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Sample records for nonpathogenic neisseria species

  1. The majority of genes in the pathogenic Neisseria species are present in non-pathogenic Neisseria lactamica, including those designated as 'virulence genes'

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    Saunders Nigel J

    2006-05-01

    Full Text Available Abstract Background Neisseria meningitidis causes the life-threatening diseases meningococcal meningitis and meningococcal septicemia. Neisseria gonorrhoeae is closely related to the meningococcus, but is the cause of the very different infection, gonorrhea. A number of genes have been implicated in the virulence of these related yet distinct pathogens, but the genes that define and differentiate the species and their behaviours have not been established. Further, a related species, Neisseria lactamica is not associated with either type of infection in normally healthy people, and lives as a harmless commensal. We have determined which of the genes so far identified in the genome sequences of the pathogens are also present in this non-pathogenic related species. Results Thirteen unrelated strains of N. lactamica were investigated using comparative genome hybridization to the pan-Neisseria microarray-v2, which contains 2845 unique gene probes. The presence of 127 'virulence genes' was specifically addressed; of these 85 are present in N. lactamica. Of the remaining 42 'virulence genes' only 11 are present in all four of the sequenced pathogenic Neisseria. Conclusion Assessment of the complete dataset revealed that the vast majority of genes present in the pathogens are also present in N. lactamica. Of the 1,473 probes to genes shared by all four pathogenic genome sequences, 1,373 hybridize to N. lactamica. These shared genes cannot include genes that are necessary and sufficient for the virulence of the pathogens, since N. lactamica does not share this behaviour. This provides an essential context for the interpretation of gene complement studies of the pathogens.

  2. Comparison of three methods for identification of pathogenic Neisseria species

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    Appelbaum, P.C.; Lawrence, R.B.

    1979-05-01

    A radiometric procedure was compared with the Minitek and Cystine Trypticase Agar sugar degradation methods for identification of 113 Neisseria species (58 Neisseria meningitidis, 51 Neisseria gonorrhoeae, 2 Neisseria lactamica, 2 Neisseria sicca). Identification of meningococci and gonoccoi was confirmed by agglutination and fluorescent antibody techniques, respectively. The Minitek method identified 97% of meningococci, 92% of gonococci, and 100% of other Neisseria after 4 h of incubation. The radiometric (Bactec) procedure identified 100% of gonococci and 100% of miscellaneous Neisseria after 3 h, but problems were encountered with meningococci: 45% of the later strains yielded index values for fructose between 20 and 28 (recommended negative cut-off point, less than 20), with strongly positive (greater than 100) glucose and maltose and negative o-nitrophenyl-beta-0-galactopyranoside reactions in all 58 strains. The Cystine Trypticase Agar method identified 91% of meningococci, ases.

  3. Field efficacy of nonpathogenic Streptomyces species against potato common scab

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    Reports of potato fields suppressive to common scab (CS) and of association of non-pathogenic streptomycetes with CS resistance suggest that non-pathogenic strains have potential to control or modulate CS disease. Biocontrol potential of non-pathogenic Streptomyces was examined in field experiments ...

  4. Analyzing the Differences and Preferences of Pathogenic and Nonpathogenic Prokaryote Species

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    Nolen, L.; Duong, K.; Heim, N. A.; Payne, J.

    2015-12-01

    A limited amount of knowledge exists on the large-scale characteristics and differences of pathogenic species in comparison to all prokaryotes. Pathogenic species, like other prokaryotes, have attributes specific to their environment and lifestyles. However, because they have evolved to coexist inside their hosts, the conditions they occupy may be more limited than those of non-pathogenic species. In this study we investigate the possibility of divergent evolution between pathogenic and non-pathogenic species by examining differences that may have evolved as a result of the need to adapt to their host. For this research we analyzed data collected from over 1900 prokaryotic species and performed t-tests using R to quantify potential differences in preferences. To examine the possible divergences from nonpathogenic bacteria, we focused on three variables: cell biovolume, preferred environmental pH, and preferred environmental temperature. We also looked at differences between pathogenic and nonpathogenic species belonging to the same phylum. Our results suggest a strong divergence in abiotic preferences between the two groups, with pathogens occupying a much smaller range of temperatures and pHs than their non-pathogenic counterparts. However, while the median biovolume is different when comparing pathogens and nonpathogens, we cannot conclude that the mean values are significantly different from each other. In addition, we found evidence of convergent evolution, as the temperature and pH preferences of pathogenic bacteria species from different phlya all approach the same values. Pathogenic species do not, however, all approach the same biovolume values, suggesting that specific pH and temperature preferences are more characteristic of pathogens than certain biovolumes.

  5. Insight of Genus Corynebacterium: Ascertaining the Role of Pathogenic and Non-pathogenic Species.

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    Oliveira, Alberto; Oliveira, Leticia C; Aburjaile, Flavia; Benevides, Leandro; Tiwari, Sandeep; Jamal, Syed B; Silva, Arthur; Figueiredo, Henrique C P; Ghosh, Preetam; Portela, Ricardo W; De Carvalho Azevedo, Vasco A; Wattam, Alice R

    2017-01-01

    This review gathers recent information about genomic and transcriptomic studies in the Corynebacterium genus, exploring, for example, prediction of pathogenicity islands and stress response in different pathogenic and non-pathogenic species. In addition, is described several phylogeny studies to Corynebacterium , exploring since the identification of species until biological speciation in one species belonging to the genus Corynebacterium . Important concepts associated with virulence highlighting the role of Pld protein and Tox gene. The adhesion, characteristic of virulence factor, was described using the sortase mechanism that is associated to anchorage to the cell wall. In addition, survival inside the host cell and some diseases, were too addressed for pathogenic corynebacteria, while important biochemical pathways and biotechnological applications retain the focus of this review for non-pathogenic corynebacteria. Concluding, this review broadly explores characteristics in genus Corynebacterium showing to have strong relevance inside the medical, veterinary, and biotechnology field.

  6. Genetic islands in pome fruit pathogenic and nonpathogenic Erwinia species and related plasmids

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    Pablo eLlop

    2015-08-01

    Full Text Available New pathogenic bacteria species belonging to the genus Erwinia associated with pome fruit trees (Erwinia pyrifoliae, E. piriflorinigrans, E. uzenensis have been increasingly described in the last years, and comparative analyses have found that all these species share several genetic characteristics. Studies at different level (whole genome comparison, virulence genes, plasmid content, etc. show a high intraspecies homogeneity (i.e. among E. amylovora strains and also abundant similarities appear between the different Erwinia species: presence of plasmids of similar size in the pathogenic species; high similarity in several genes associated with exopolysaccharide production and hence, with virulence, as well as in some other genes, in the chromosomes. Many genetic similarities have been observed also among some of the plasmids (and genomes from the pathogenic species and E. tasmaniensis or E. billingiae, two epiphytic species on the same hosts. The amount of genetic material shared in this genus varies from individual genes to clusters, genomic islands and genetic material that even may constitute a whole plasmid. Recent research on evolution of erwinias point out the horizontal transfer acquisition of some genomic islands that were subsequently lost in some species and several pathogenic traits that are still present. How this common material has been obtained and is efficiently maintained in different species belonging to the same genus sharing a common ecological niche provides an idea of the origin and evolution of the pathogenic Erwinia and the interaction with nonpathogenic species present in the same niche, and the role of the genes that are conserved in all of them.

  7. Arginase activity in pathogenic and non-pathogenic species of Leishmania parasites.

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    Badirzadeh, Alireza; Taheri, Tahereh; Taslimi, Yasaman; Abdossamadi, Zahra; Heidari-Kharaji, Maryam; Gholami, Elham; Sedaghat, Baharehsadat; Niyyati, Maryam; Rafati, Sima

    2017-07-01

    Proliferation of Leishmania (L.) parasites depends on polyamine availability, which can be generated by the L-arginine catabolism and the enzymatic activity of arginase (ARG) of the parasites and of the mammalian hosts. In the present study, we characterized and compared the arginase (arg) genes from pathogenic L. major and L. tropica and from non-pathogenic L. tarentolae. We quantified the level of the ARG activity in promastigotes and macrophages infected with pathogenic L. major and L. tropica and non-pathogenic L. tarentolae amastigotes. The ARG's amino acid sequences of the pathogenic and non-pathogenic Leishmania demonstrated virtually 98.6% and 88% identities with the reference L. major Friedlin ARG. Higher ARG activity was observed in all pathogenic promastigotes as compared to non-pathogenic L. tarentolae. In vitro infection of human macrophage cell line (THP1) with pathogenic and non-pathogenic Leishmania spp. resulted in increased ARG activities in the infected macrophages. The ARG activities present in vivo were assessed in susceptible BALB/c and resistant C57BL/6 mice infected with L. major, L. tropica and L. tarentolae. We demonstrated that during the development of the infection, ARG is induced in both strains of mice infected with pathogenic Leishmania. However, in L. major infected BALB/c mice, the induction of ARG and parasite load increased simultaneously according to the time course of infection, whereas in C57BL/6 mice, the enzyme is upregulated solely during the period of footpad swelling. In L. tropica infected mice, the footpads' swellings were slow to develop and demonstrated minimal cutaneous pathology and ARG activity. In contrast, ARG activity was undetectable in mice inoculated with the non-pathogenic L. tarentolae. Our data suggest that infection by Leishmania parasites can increase ARG activity of the host and provides essential polyamines for parasite salvage and its replication. Moreover, the ARG of Leishmania is vital for parasite

  8. Carriage of Neisseria Species in Communities with Different Rates of Meningococcal Disease

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    Nicole Le Saux

    1992-01-01

    Full Text Available A single clone, Neisseria meningitidis serogroup C (C:2a:P1.2, was isolated from seven patients during a cluster of cases of meningococcal disease in Ontario in 1989. To determine whether the clone was present in asymptomatic individuals in the same population, pharyngeal swabs were taken from 7% (644 of 9125 of residents who were vaccinated during the outbreak. Rates of isolation of Neisseria species were also compared to those in two other geographical areas which did not have an elevated incidence of meningococcal disease. The rate of carriage of N meningitidis in the asymptomatic individuals sampled was between 1.9% and 5.4%. The clone isolated from patients was not present among the carrier strains as determined by sero- and subtyping and electrophoretic analysis of metabolic enzymes. Age greater than six years was the only factor associated with colonization with N meningitidis.

  9. Differentiated THP-1 Cells Exposed to Pathogenic and Nonpathogenic Borrelia Species Demonstrate Minimal Differences in Production of Four Inflammatory Cytokines.

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    Stokes, John V; Moraru, Gail M; McIntosh, Chelsea; Kummari, Evangel; Rausch, Keiko; Varela-Stokes, Andrea S

    2016-11-01

    Tick-borne borreliae include Lyme disease and relapsing fever agents, and they are transmitted primarily by ixodid (hard) and argasid (soft) tick vectors, respectively. Tick-host interactions during feeding are complex, with host immune responses influenced by biological differences in tick feeding and individual differences within and between host species. One of the first encounters for spirochetes entering vertebrate host skin is with local antigen-presenting cells, regardless of whether the tick-associated Borrelia sp. is pathogenic. In this study, we performed a basic comparison of cytokine responses in THP-1-derived macrophages after exposure to selected borreliae, including a nonpathogen. By using THP-1 cells, differentiated to macrophages, we eliminated variations in host response and reduced the system to an in vitro model to evaluate the extent to which the Borrelia spp. influence cytokine production. Differentiated THP-1 cells were exposed to four Borrelia spp., Borrelia hermsii (DAH), Borrelia burgdorferi (B31), B. burgdorferi (NC-2), or Borrelia lonestari (LS-1), or lipopolysaccharides (LPS) (activated) or media (no treatment) controls. Intracellular and secreted interferon (IFN)-γ, interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α were measured using flow cytometric and Luminex-based assays, respectively, at 6, 24, and 48 h postexposure time points. Using a general linear model ANOVA for each cytokine, treatment (all Borrelia spp. and LPS compared to no treatment) had a significant effect on secreted TNF-α only. Time point had a significant effect on intracellular IFN-γ, TNF-α and IL-6. However, we did not see significant differences in selected cytokines among Borrelia spp. Thus, in this model, we were unable to distinguish pathogenic from nonpathogenic borreliae using the limited array of selected cytokines. While unique immune profiles may be detectable in an in vitro model and may reveal predictors for pathogenicity in borreliae

  10. Some South African Rubiaceae Tree Leaf Extracts Have Antimycobacterial Activity Against Pathogenic and Non-pathogenic Mycobacterium Species.

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    Aro, Abimbola O; Dzoyem, Jean P; Hlokwe, Tiny M; Madoroba, Evelyn; Eloff, Jacobus N; McGaw, Lyndy J

    2015-07-01

    Tuberculosis (TB) caused by Mycobacterium tuberculosis remains an ongoing threat to human health. Many plant species contain antimycobacterial compounds, which may serve as template molecules for new anti-TB drugs. The Rubiaceae family is the largest family of trees in southern Africa, and preliminary evidence revealed antimycobacterial activity in several species of the genus, motivating further studies. Leaf extracts of 15 tree species from the Rubiaceae family were screened for antimycobacterial activity against pathogenic M. tuberculosis and non-pathogenic Mycobacterium smegmatis, Mycobacterium aurum and Mycobacterium bovis BCG (Bacillus Calmette-Guérin) using a twofold serial microdilution assay. Cytotoxicity was determined using a tetrazolium-based colorimetric assay against C3A liver cells and Vero kidney cells. Minimum inhibitory concentration values as low as 0.04 mg/mL against M. smegmatis and M. tuberculosis were recorded. Activity against M. aurum was the best predictor of activity against pathogenic M. tuberculosis (correlation coefficient = 0.9). Bioautography indicated at least 40 different antimycobacterial compounds in the extracts. Cytotoxicity of the extracts varied, and Oxyanthus speciosus had the most promising selectivity index values. Copyright © 2015 John Wiley & Sons, Ltd.

  11. The use of high-throughput DNA sequencing in the investigation of antigenic variation: application to Neisseria species.

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    John K Davies

    Full Text Available Antigenic variation occurs in a broad range of species. This process resembles gene conversion in that variant DNA is unidirectionally transferred from partial gene copies (or silent loci into an expression locus. Previous studies of antigenic variation have involved the amplification and sequencing of individual genes from hundreds of colonies. Using the pilE gene from Neisseria gonorrhoeae we have demonstrated that it is possible to use PCR amplification, followed by high-throughput DNA sequencing and a novel assembly process, to detect individual antigenic variation events. The ability to detect these events was much greater than has previously been possible. In N. gonorrhoeae most silent loci contain multiple partial gene copies. Here we show that there is a bias towards using the copy at the 3' end of the silent loci (copy 1 as the donor sequence. The pilE gene of N. gonorrhoeae and some strains of Neisseria meningitidis encode class I pilin, but strains of N. meningitidis from clonal complexes 8 and 11 encode a class II pilin. We have confirmed that the class II pili of meningococcal strain FAM18 (clonal complex 11 are non-variable, and this is also true for the class II pili of strain NMB from clonal complex 8. In addition when a gene encoding class I pilin was moved into the meningococcal strain NMB background there was no evidence of antigenic variation. Finally we investigated several members of the opa gene family of N. gonorrhoeae, where it has been suggested that limited variation occurs. Variation was detected in the opaK gene that is located close to pilE, but not at the opaJ gene located elsewhere on the genome. The approach described here promises to dramatically improve studies of the extent and nature of antigenic variation systems in a variety of species.

  12. Where does Neisseria acquire foreign DNA from: an examination of the source of genomic and pathogenic islands and the evolution of the Neisseria genus.

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    Putonti, Catherine; Nowicki, Bogdan; Shaffer, Michael; Fofanov, Yuriy; Nowicki, Stella

    2013-09-04

    Pathogenicity islands (PAIs) or genomic islands (GEIs) are considered to be the result of a recent horizontal transfer. Detecting PAIs/GEIs as well as their putative source can provide insight into the organism's pathogenicity within its host. Previously we introduced a tool called S-plot which provides a visual representation of the variation in compositional properties across and between genomic sequences. Utilizing S-plot and new functionality developed here, we examined 18 publicly available Neisseria genomes, including strains of both pathogenic and non-pathogenic species, in order to identify regions of unusual compositional properties (RUCPs) using both a sliding window as well as a gene-by-gene approach. Numerous GEIs and PAIs were identified including virulence genes previously found within the pathogenic Neisseria species. While some genes were conserved amongst all species, only pathogenic species, or an individual species, a number of genes were detected that are unique to an individual strain. While the majority of such genes have an origin unknown, a number of putative sources including pathogenic and capsule-containing bacteria were determined, indicative of gene exchange between Neisseria spp. and other bacteria within their microhabitat. Furthermore, we uncovered evidence that both N. meningitidis and N. gonorrhoeae have separately acquired DNA from their human host. Data suggests that all three Neisseria species have received horizontally transferred elements post-speciation. Using this approach, we were able to not only find previously identified regions of virulence but also new regions which may be contributing to the virulence of the species. This comparative analysis provides a means for tracing the evolutionary history of the acquisition of foreign DNA within this genus. Looking specifically at the RUCPs present within the 18 genomes considered, a stronger similarity between N. meningitidis and N. lactamica is observed, suggesting that N

  13. Functional analysis of the interdependence between DNA uptake sequence and its cognate ComP receptor during natural transformation in Neisseria species.

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    Jamie-Lee Berry

    Full Text Available Natural transformation is the widespread biological process by which "competent" bacteria take up free DNA, incorporate it into their genomes, and become genetically altered or "transformed". To curb often deleterious transformation by foreign DNA, several competent species preferentially take up their own DNA that contains specific DUS (DNA uptake sequence watermarks. Our recent finding that ComP is the long sought DUS receptor in Neisseria species paves the way for the functional analysis of the DUS-ComP interdependence which is reported here. By abolishing/modulating ComP levels in Neisseria meningitidis, we show that the enhancement of transformation seen in the presence of DUS is entirely dependent on ComP, which also controls transformation in the absence of DUS. While peripheral bases in the DUS were found to be less important, inner bases are essential since single base mutations led to dramatically impaired interaction with ComP and transformation. Strikingly, naturally occurring DUS variants in the genomes of human Neisseria commensals differing from DUS by only one or two bases were found to be similarly impaired for transformation of N. meningitidis. By showing that ComPsub from the N. subflava commensal specifically binds its cognate DUS variant and mediates DUS-enhanced transformation when expressed in a comP mutant of N. meningitidis, we confirm that a similar mechanism is used by all Neisseria species to promote transformation by their own, or closely related DNA. Together, these findings shed new light on the molecular events involved in the earliest step in natural transformation, and reveal an elegant mechanism for modulating horizontal gene transfer between competent species sharing the same niche.

  14. Independent evolution of the core and accessory gene sets in the genus Neisseria: insights gained from the genome of Neisseria lactamica isolate 020-06

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    White Brian

    2010-11-01

    Full Text Available Abstract Background The genus Neisseria contains two important yet very different pathogens, N. meningitidis and N. gonorrhoeae, in addition to non-pathogenic species, of which N. lactamica is the best characterized. Genomic comparisons of these three bacteria will provide insights into the mechanisms and evolution of pathogenesis in this group of organisms, which are applicable to understanding these processes more generally. Results Non-pathogenic N. lactamica exhibits very similar population structure and levels of diversity to the meningococcus, whilst gonococci are essentially recent descendents of a single clone. All three species share a common core gene set estimated to comprise around 1190 CDSs, corresponding to about 60% of the genome. However, some of the nucleotide sequence diversity within this core genome is particular to each group, indicating that cross-species recombination is rare in this shared core gene set. Other than the meningococcal cps region, which encodes the polysaccharide capsule, relatively few members of the large accessory gene pool are exclusive to one species group, and cross-species recombination within this accessory genome is frequent. Conclusion The three Neisseria species groups represent coherent biological and genetic groupings which appear to be maintained by low rates of inter-species horizontal genetic exchange within the core genome. There is extensive evidence for exchange among positively selected genes and the accessory genome and some evidence of hitch-hiking of housekeeping genes with other loci. It is not possible to define a 'pathogenome' for this group of organisms and the disease causing phenotypes are therefore likely to be complex, polygenic, and different among the various disease-associated phenotypes observed.

  15. Enfoques mucosales en vacunologia de Neisseria

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    Pérez O

    2009-08-01

    Full Text Available Meningococcal B strains accounts for some 72% and 28% of meningococcal diseases in infants and toddlers in Europe and the USA, respectively. Nevertheless, meningococcal diseases are rare in Cuba owing to the wide spread program on antimeningococcal vaccination in the country. Finlay Institute is one of the pioneering organizations in Neisseria Vaccinology mainly by its contribution to N. meningitidis serogroup B outer membrane-based bivalent vaccine, VA-MENGOC-BC™. This vaccine was given intramuscularly in more than 60 million doses corresponding 10.7 millions of them to Cuban young adults, children, and infants. However, most dangerous or commensally Neisseria strains enter and establish in the mucosa, where the secretory (S IgA is the main specific guardian and is mainly induced by mucosal routes. However, few mucosal vaccines exist principally due to the absent of mucosal adjuvants. We develop a Finlay Adjuvant (AF platform based in outer membrane vesicles (Proteoliposome, PL and its derivate Cochleate (Co. AFPL1 derived from serogroup B N. meningitidis is a potent Th1/CTL driving parenteral adjuvant. AFCo1 is a potent mucosal adjuvant. Therefore, we sought to go deeper in the possible mucosal cross recognition between N. meningitidis serogroups and Neisseria species and explore a concurrent mucosal and parenteral immunization strategy (SinTimVaS in order to develop suitable mucosal vaccines. Experiments were conducted in Balb/c or C57Bl6 mice with mucosal and systemic immunization using AFCo1 and AFPL1. Human sera and saliva were also analyzed for cross cognition. Mucosal cross recognition at SIgA level in human saliva between N. meningitidis serogroups B, A, C, Y, and W135 were observed. This SIgA cross recognition response was also observed between pathogenic (N. meningitidis serogroup B, N. gonorrhoeae and non-pathogenic strains (N. flava, N. lactamica. The possible influence of meningococcal vaccination against Gonorrhea was also

  16. Genetic distribution of noncapsular meningococcal group B vaccine antigens in Neisseria lactamica.

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    Lucidarme, Jay; Gilchrist, Stefanie; Newbold, Lynne S; Gray, Stephen J; Kaczmarski, Edward B; Richardson, Lynne; Bennett, Julia S; Maiden, Martin C J; Findlow, Jamie; Borrow, Ray

    2013-09-01

    The poor immunogenicity of the meningococcal serogroup B (MenB) capsule has led to the development of vaccines targeting subcapsular antigens, in particular the immunodominant and diverse outer membrane porin, PorA. These vaccines are largely strain specific; however, they offer limited protection against the diverse MenB-associated diseases observed in many industrialized nations. To broaden the scope of its protection, the multicomponent vaccine (4CMenB) incorporates a PorA-containing outer membrane vesicle (OMV) alongside relatively conserved recombinant protein components, including factor H-binding protein (fHbp), Neisseria adhesin A (NadA), and neisserial heparin-binding antigen (NHBA). The expression of PorA is unique to meningococci (Neisseria meningitidis); however, many subcapsular antigens are shared with nonpathogenic members of the genus Neisseria that also inhabit the nasopharynx. These organisms may elicit cross-protective immunity against meningococci and/or occupy a niche that might otherwise accommodate pathogens. The potential for 4CMenB responses to impact such species (and vice versa) was investigated by determining the genetic distribution of the primary 4CMenB antigens among diverse members of the common childhood commensal, Neisseria lactamica. All the isolates possessed nhba but were devoid of fhbp and nadA. The nhba alleles were mainly distinct from but closely related to those observed among a representative panel of invasive MenB isolates from the same broad geographic region. We made similar findings for the immunogenic typing antigen, FetA, which constitutes a major part of the 4CMenB OMV. Thus, 4CMenB vaccine responses may impact or be impacted by nasopharyngeal carriage of commensal neisseriae. This highlights an area for further research and surveillance should the vaccine be routinely implemented.

  17. Live Streptococcus pneumoniae, Haemophilus influenzae, and Neisseria meningitidis activate the inflammatory response trhough Toll-like receptors 2, 4, and 9 in species-specific patterns

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    Mogensen, T.H.; Paludan, Søren Riis; Kilian, Mogens

    2006-01-01

    activation by live bacteria. Here, we demonstrate that live Streptococcus pneumoniae, Haemophilus influenzae type b, and Neisseria meningitidis, the three principal causes of bacterial meningitis, use distinct sets of TLRs to trigger the inflammatory response. Using human embryonic kidney 293 cell lines......, each overexpressing one type of TLR, we found that S. pneumoniae triggered activation of the transcription factor nuclear factor-kappaB and expression of interleukin-8, only in cells expressing TLR2 or -9. The same response was evoked by H. influenzae in cells expressing TLR2 or -4 and by N...... and confirmed the essential role of these TLRs and also identified differential functions of TLRs in activation of the inflammatory response. Collectively, we here demonstrate that S. pneumoniae, H. influenzae, and N. meningitidis each activate several TLRs in species-specific patterns and show that infection...

  18. NeisseriaBase: a specialised Neisseria genomic resource and analysis platform

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    Wenning Zheng

    2016-03-01

    Full Text Available Background. The gram-negative Neisseria is associated with two of the most potent human epidemic diseases: meningococcal meningitis and gonorrhoea. In both cases, disease is caused by bacteria colonizing human mucosal membrane surfaces. Overall, the genus shows great diversity and genetic variation mainly due to its ability to acquire and incorporate genetic material from a diverse range of sources through horizontal gene transfer. Although a number of databases exist for the Neisseria genomes, they are mostly focused on the pathogenic species. In this present study we present the freely available NeisseriaBase, a database dedicated to the genus Neisseria encompassing the complete and draft genomes of 15 pathogenic and commensal Neisseria species. Methods. The genomic data were retrieved from National Center for Biotechnology Information (NCBI and annotated using the RAST server which were then stored into the MySQL database. The protein-coding genes were further analyzed to obtain information such as calculation of GC content (%, predicted hydrophobicity and molecular weight (Da using in-house Perl scripts. The web application was developed following the secure four-tier web application architecture: (1 client workstation, (2 web server, (3 application server, and (4 database server. The web interface was constructed using PHP, JavaScript, jQuery, AJAX and CSS, utilizing the model-view-controller (MVC framework. The in-house developed bioinformatics tools implemented in NeisseraBase were developed using Python, Perl, BioPerl and R languages. Results. Currently, NeisseriaBase houses 603,500 Coding Sequences (CDSs, 16,071 RNAs and 13,119 tRNA genes from 227 Neisseria genomes. The database is equipped with interactive web interfaces. Incorporation of the JBrowse genome browser in the database enables fast and smooth browsing of Neisseria genomes. NeisseriaBase includes the standard BLAST program to facilitate homology searching, and for Virulence

  19. NeisseriaBase: a specialised Neisseria genomic resource and analysis platform.

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    Zheng, Wenning; Mutha, Naresh V R; Heydari, Hamed; Dutta, Avirup; Siow, Cheuk Chuen; Jakubovics, Nicholas S; Wee, Wei Yee; Tan, Shi Yang; Ang, Mia Yang; Wong, Guat Jah; Choo, Siew Woh

    2016-01-01

    Background. The gram-negative Neisseria is associated with two of the most potent human epidemic diseases: meningococcal meningitis and gonorrhoea. In both cases, disease is caused by bacteria colonizing human mucosal membrane surfaces. Overall, the genus shows great diversity and genetic variation mainly due to its ability to acquire and incorporate genetic material from a diverse range of sources through horizontal gene transfer. Although a number of databases exist for the Neisseria genomes, they are mostly focused on the pathogenic species. In this present study we present the freely available NeisseriaBase, a database dedicated to the genus Neisseria encompassing the complete and draft genomes of 15 pathogenic and commensal Neisseria species. Methods. The genomic data were retrieved from National Center for Biotechnology Information (NCBI) and annotated using the RAST server which were then stored into the MySQL database. The protein-coding genes were further analyzed to obtain information such as calculation of GC content (%), predicted hydrophobicity and molecular weight (Da) using in-house Perl scripts. The web application was developed following the secure four-tier web application architecture: (1) client workstation, (2) web server, (3) application server, and (4) database server. The web interface was constructed using PHP, JavaScript, jQuery, AJAX and CSS, utilizing the model-view-controller (MVC) framework. The in-house developed bioinformatics tools implemented in NeisseraBase were developed using Python, Perl, BioPerl and R languages. Results. Currently, NeisseriaBase houses 603,500 Coding Sequences (CDSs), 16,071 RNAs and 13,119 tRNA genes from 227 Neisseria genomes. The database is equipped with interactive web interfaces. Incorporation of the JBrowse genome browser in the database enables fast and smooth browsing of Neisseria genomes. NeisseriaBase includes the standard BLAST program to facilitate homology searching, and for Virulence Factor

  20. Susceptibility of pathogenic and nonpathogenic Naegleria ssp

    International Nuclear Information System (INIS)

    Whiteman, L.Y.

    1988-01-01

    The susceptibility of four species of Naegleria amoebae to complement-mediated lysis was determined. The amoebicidal activity of normal human serum (NHS) and normal guinea pig serum (NGPS) for Naegleria amoebae was measured by an in vitro cytotoxicity assay. Release of radioactivity from amoebae labeled with 3 H-uridine and visual observation with a compound microscope were used as indices of lysis. Susceptibility or resistance to complement-mediated lysis in vitro correlated with the in vivo pathogenic potential. Nonpathogenic Naegleria amoebae were lysed at a faster rate and at higher cell concentrations than were pathogenic amoebae. Electrophoretic analysis of NHS incubated with pathogenic or nonpathogenic Naegleria spp. demonstrated that amoebae activate the complement cascade resulting in the production of C3 and C5 complement cleavage products. Treatment with papain or trypsin for 1 h, but not with sialidase, increase the susceptibility of highly pathogenic, mouse-passaged N. fowleri to lysis. Treatment with actinomycin D, cycloheximide or various protease inhibitors for 4 h did not increase susceptibility to lysis. Neither a repair process involving de novo protein synthesis nor a complement-inactivating protease appear to account for the increase resistance of N. fowleri amoebae to complement-mediated lysis. A binding study with 125 I radiolabeled C9 indicated that the terminal complement component does not remain stably bound to the membrane of pathogenic amoebae

  1. Production of 14C-labeled gas in BACTEC Neisseria Differentiation kits by Neisseria cinerea

    International Nuclear Information System (INIS)

    Boyce, J.M.; Mitchell, E.B. Jr.; Knapp, J.S.; Buttke, T.M.

    1985-01-01

    Six strains of Neisseria cinerea were tested in BACTEC Neisseria Differentiation kits (Johnston Laboratories, Inc., Towson, Md.), and all yielded positive glucose growth indices and negative maltose and fructose growth indices. These results were similar to those achieved with Neisseria gonorrhoeae. However, most of the N. cinerea isolates tested yielded 3-h glucose growth indices that were lower than those obtained with gonococci. 14 C-labeled gas was produced significantly faster by N. gonorrhoeae than by N. cinerea. Additional studies suggested that the 14 C-labeled gas produced by N. cinerea was carbon dioxide. N. cinerea strains were similar to Branhamella catarrhalis strains because both species failed to produce detectable acid from glucose, maltose, sucrose, fructose, and lactose in cysteine-tryptic agar media. However, in contrast to N. cinerea strains, B. catarrhalis strains did not metabolize glucose in BACTEC Neisseria Differentiation kits

  2. Riboregulation in Neisseria meningitidis

    NARCIS (Netherlands)

    Huis in 't Veld, R.A.G.

    2017-01-01

    Neisseria meningitidis (the meningococcus) is primarily a commensal of the human oropharynx that sporadically causes septicemia and meningitis. Meningococci adapt to diverse local host conditions that differ in nutrient supply such as the nasopharynx, blood and cerebrospinal fluid by changing

  3. The Biology of Neisseria Adhesins

    Directory of Open Access Journals (Sweden)

    Miao-Chiu Hung

    2013-07-01

    Full Text Available Members of the genus Neisseria include pathogens causing important human diseases such as meningitis, septicaemia, gonorrhoea and pelvic inflammatory disease syndrome. Neisseriae are found on the exposed epithelia of the upper respiratory tract and the urogenital tract. Colonisation of these exposed epithelia is dependent on a repertoire of diverse bacterial molecules, extending not only from the surface of the bacteria but also found within the outer membrane. During invasive disease, pathogenic Neisseriae also interact with immune effector cells, vascular endothelia and the meninges. Neisseria adhesion involves the interplay of these multiple surface factors and in this review we discuss the structure and function of these important molecules and the nature of the host cell receptors and mechanisms involved in their recognition. We also describe the current status for recently identified Neisseria adhesins. Understanding the biology of Neisseria adhesins has an impact not only on the development of new vaccines but also in revealing fundamental knowledge about human biology.

  4. Rhamnolipids from non-pathogenic Burkholderia thailandensis E264: Physicochemical characterization, antimicrobial and antibiofilm efficacy against oral hygiene related pathogens.

    Science.gov (United States)

    Elshikh, Mohamed; Funston, Scott; Chebbi, Alif; Ahmed, Syed; Marchant, Roger; Banat, Ibrahim M

    2017-05-25

    Biosurfactants are naturally occurring surface active compounds that have mainly been exploited for environmental applications and consumer products, with their biomedical efficacy an emerging area of research. Rhamnolipids area major group of biosurfactants that have been reported for their antimicrobial and antibiofilm efficacy. One of the main limiting factors for scaled up production and downstream applications of rhamnolipids is the fact that they are predominantly produced from the opportunistic pathogen Pseudomonas aeruginosa. In this article, we have reported the production and characterisation of long chain rhamnolipids from non-pathogenic Burkholderia thailandensis E264 (ATCC 700388). We have also investigated the antibacterial and antibiofilm properties of these rhamnolipids against some oral pathogens (Streptococcus oralis, Actinomyces naeslundii, Neisseria mucosa and Streptococcus sanguinis), important for oral health and hygiene. Treating these bacteria with different concentrations of long chain rhamnolipids resulted in a reduction of 3-4 log of bacterial viability, placing these rhamnolipids close to being classified as biocidal. Investigating long chain rhamnolipid efficacy as antibiofilm agents for prospective oral-related applications revealed good potency against oral-bacteria biofilms in a co-incubation experiments, in a pre-coated surface format, in disrupting immature biofilms and has shown excellent combination effect with Lauryl Sodium Sulphate which resulted in a drastic decrease in its minimal inhibitory concentration against different bacteria. Investigating the rhamnolipid permeabilization effect along with their ability to induce the formation of reactive oxygen species has shed light on the mechanism through which inhibition/killing of bacteria may occur. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Definition of a virulence-related antigen of Neisseria gonorrhoeae with monoclonal antibodies and lectins.

    Science.gov (United States)

    Demarco de Hormaeche, R; Bundell, C; Chong, H; Taylor, D W; Wildy, P

    1986-03-01

    Variants of one strain of Neisseria gonorrhoeae, grown in vivo or in vitro, that have been previously shown to differ in infectivity, serum resistance, and capsule production were compared with use of monoclonal antibodies and lectins. Monoclonal antibodies to virulent gonococci recognized an antigenic site of the lipopolysaccharide (LPS) produced in large amounts by gonococci grown in vivo but present only in a small proportion of in vitro-grown gonococci. This antigen (C-LPS) was found in all 85 different gonococcal isolates studied but not among nonpathogenic neisseriae. It was shared by group B and C meningococci but not by groups A and D. Enzyme-linked immunosorbent assay and Western blot analysis showed that N-acetylglucosamine and N-acetylgalactosamine form part of the epitope. The C-LPS antigen was shown by immunofluorescence to be present on the surface of the gonococci and also free as slime. This antigen appears to confer resistance to killing by normal sera.

  6. Environmental survival of Neisseria meningitidis.

    Science.gov (United States)

    Tzeng, Y-L; Martin, L E; Stephens, D S

    2014-01-01

    Neisseria meningitidis is transmitted through the inhalation of large human respiratory droplets, but the risk from contaminated environmental surfaces is controversial. Compared to Streptococcus pneumoniae and Acinetobacter baumanni, meningococcal viability after desiccation on plastic, glass or metal surfaces decreased rapidly, but viable meningococci were present for up to 72 h. Encapsulation did not provide an advantage for meningococcal environmental survival on environmental surfaces.

  7. A novel approach for differentiating pathogenic and non-pathogenic Leptospira based on molecular fingerprinting.

    Science.gov (United States)

    Xiao, Di; Zhang, Cuicai; Zhang, Huifang; Li, Xiuwen; Jiang, Xiugao; Zhang, Jianzhong

    2015-04-24

    Leptospirosis is a worldwide, deadly zoonotic disease. Pathogenic Leptospira causes leptospirosis. The rapid and accurate identification of pathogenic and non-pathogenic Leptospira strains is essential for appropriate therapeutic management and timely intervention for infection control. The molecular fingerprint is a simple and rapid alternative tool for microorganisms identification, which is based on matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). In this study, molecular fingerprint was performed to identify pathogenic strains of Leptospira. Phylogenetic analysis based on 16S rRNA gene sequences was used as the reference method. In addition, a label-free technique was used to reveal the different proteins of pathogenic or non-pathogenic Leptospira. A reference database was constructed using 30 Leptospira strains, including 16 pathogenic strains and 14 non-pathogenic strains. Two super reference spectra that were associated with pathogenicity were established. Overall, 33 Leptospira strains were used for validation, and 32 of 33 Leptospira strains could be identified on the species level and all the 33 could be classified as pathogenic or non-pathogenic. The super reference spectra and the major spectra projection (MSP) dendrogram correctly categorized the Leptospira strains into pathogenic and non-pathogenic groups, which was consistent with the 16S rRNA reference methods. Between the pathogenic and non-pathogenic strains, 108 proteins were differentially expressed. molecular fingerprint is an alternative to conventional molecular identification and can rapidly distinguish between pathogenic and non-pathogenic Leptospira strains. Therefore, molecular fingerprint may play an important role in the clinical diagnosis, treatment, surveillance, and tracking of epidemic outbreaks of leptospirosis. Leptospirosis is a worldwide zoonosis that is caused by spirochetes of the genus Leptospira. Leptospirosis is a serious zoonotic

  8. Algunas consideraciones sobre Neisseria gonorrhoeae

    OpenAIRE

    Pardi, Germán; Pérez, María Fernanda; Pacheco, Aura; Mata de Henning, Magdalena

    2004-01-01

    En el presente artículo, se describen los principales aspectos relacionados con Neisseria gonorrhoeae, microorganismo que se puede encontrar presente como parte de la microbiota transitoria o transeúnte de la cavidad bucal de algunos individuos, donde se destacan: Historia, taxonomía, características morfológicas, fisiológicas y de cultivo, ultraestructura, estructura antigénica, así como algunas consideraciones en referencia a la ecología y a los mecanismos de patogenicidad por parte de esta...

  9. Comparison of the cystine-tryptic digest agar-carbohydrate co-agglutination and BACTEC Neisseria differentiation methods for identification of Neisseria gonorrhoeae in the clinical laboratory

    International Nuclear Information System (INIS)

    Morello, J.A.; Beheshti, S.; Bohnhoff, M.

    1980-01-01

    The author evaluated CTA-carbohydrate, BACTEC and co-agglutination systems to determine their accuracy for identifying N. gonorrhoeae strains and for distinguishing them from other Neisseria species. BACTEC is a radiometric assay based on the measurement of liberated radiolabelled CO 2 from metabolised carbohydrates which have been tagged with 14 C. (Auth.)

  10. Antimicrobial susceptibility pattern of Neisseria gonorrhoeae ...

    African Journals Online (AJOL)

    The high levels of bacterial resistance against ampicillin, ciprofloxacin, tetracycline, penicillin and spectinomycin, should be taken into account in developing any new guidelines in the management of the infection. Keywords: Neisseria gonorrhoeae, Female infertility Drug Resistance, Ciprofloxacin, Tetracycline, ...

  11. Phylogeographic Diversity of Pathogenic and Non-Pathogenic Hantaviruses in Slovenia

    Science.gov (United States)

    Korva, Miša; Knap, Nataša; Resman Rus, Katarina; Fajs, Luka; Grubelnik, Gašper; Bremec, Matejka; Knapič, Tea; Trilar, Tomi; Avšič Županc, Tatjana

    2013-01-01

    Slovenia is a very diverse country from a natural geography point of view, with many different habitats within a relatively small area, in addition to major geological and climatic differences. It is therefore not surprising that several small mammal species have been confirmed to harbour hantaviruses: A. flavicollis (Dobrava virus), A. agrarius (Dobrava virus–Kurkino), M. glareolus (Puumala virus), S. areanus (Seewis virus), M. agrestis, M. arvalis and M. subterraneus (Tula virus). Three of the viruses, namely the Dobrava, Dobrava–Kurkino and Puumala viruses, cause disease in humans, with significant differences in the severity of symptoms. Due to changes in haemorrhagic fever with renal syndrome cases (HFRS) epidemiology, a detailed study on phylogenetic diversity and molecular epidemiology of pathogenic and non-pathogenic hantaviruses circulating in ecologically diverse endemic regions was performed. The study presents one of the largest collections of hantavirus L, M and S sequences obtained from hosts and patients within a single country. Several genetic lineages were determined for each hantavirus species, with higher diversity among non-pathogenic compared to pathogenic viruses. For pathogenic hantaviruses, a significant geographic clustering of human- and rodent-derived sequences was confirmed. Several geographic and ecological factors were recognized as influencing and limiting the formation of endemic areas. PMID:24335778

  12. Cephalosporin resistance in Neisseria gonorrhoeae

    Directory of Open Access Journals (Sweden)

    Manju Bala

    2010-01-01

    Full Text Available Gonorrhea, a disease of public health importance, not only leads to high incidence of acute infections and complications but also plays a major role in facilitating human immunodeficiency virus (HIV acquisition and transmission. One of the major public health needs for gonorrhea control is appropriate, effective treatment. However, treatment options for gonorrhea are diminishing as Neisseria gonorrhoeae have developed resistance to several antimicrobial drugs such as sulfonamides, penicillin, tetracyclines and quinolones. Antimicrobial resistance (AMR surveillance of N. gonorrhoeae helps establish and maintain the efficacy of standard treatment regimens. AMR surveillance should be continuous to reveal the emergence of new resistant strains, monitor the changing patterns of resistance, and be able to update treatment recommendations so as to assist in disease control. Current treatment guidelines recommend the use of single dose injectable or oral cephalosporins. The emergence and spread of cephalosporin resistant and multi drug resistant N. gonorrhoeae strains, represents a worrying trend that requires monitoring and investigation. Routine clinical laboratories need to be vigilant for the detection of such strains such that strategies for control and prevention could be reviewed and revised from time to time. It will be important to elucidate the genetic mechanisms responsible for decreased susceptibility and future resistance. There is also an urgent need for research of safe, alternative anti-gonococcal compounds that can be administered orally and have effective potency, allowing high therapeutic efficacy (greater than 95.0% cure rate.

  13. Use of Green Fluorescent Protein-Transgenic Strains to Study Pathogenic and Nonpathogenic Lifestyles in Colletotrichum acutatum.

    Science.gov (United States)

    Horowitz, Sigal; Freeman, Stanley; Sharon, Amir

    2002-07-01

    ABSTRACT Colletotrichum acutatum, which causes anthracnose disease on strawberry, can also persist on several other plant species without causing disease symptoms. The genetic and molecular bases that determine pathogenic and nonpathogenic lifestyles in C. acutatum are unclear. We developed a transformation system for C. acutatum by electroporation of germinating conidia, and transgenic isolates that express the green fluorescent protein (GFP) were produced. Details of the pathogenic and nonpathogenic lifestyles of C. acutatum were determined by using GFP-transgenic isolates. Major differences between colonization-mediating processes of strawberry and of other plants were observed. On the main host, strawberry, the germinating conidia formed branched, thick hyphae, and large numbers of appressoria were produced that were essential for plant penetration. In strawberry, the fungus developed rapidly, filling the mesophyll with dense mycelium that invaded the cells and caused necrosis of the tissue. In nonpathogenic interactions on pepper, eggplant, and tomato, the conidia germinated, producing thin, straight germ tubes. Appressoria were produced but failed to germinate and penetrate leaf tissue, resulting in epiphytic growth without invasion of the plant. Penetration of the plant occurred only several days after inoculation and was restricted to the intercellular spaces of the first cell layers of infected tissue without causing any visible damage. Much of the new fungal biomass continued to develop on the surface of inoculated organs in the nonpathogenic interaction. The differences in fungal development on strawberry compared with the other plant species suggest that signal molecules, which may be present only in strawberry, trigger appressorial germination and penetration of the primary host.

  14. A new oligonucleotide microarray for detection of pathogenic and non-pathogenic Legionella spp.

    Directory of Open Access Journals (Sweden)

    Boyang Cao

    Full Text Available Legionella pneumophila has been recognized as the major cause of legionellosis since the discovery of the deadly disease. Legionella spp. other than L. pneumophila were later found to be responsible to many non-pneumophila infections. The non-L. pneumophila infections are likely under-detected because of a lack of effective diagnosis. In this report, we have sequenced the 16S-23S rRNA gene internal transcribed spacer (ITS of 10 Legionella species and subspecies, including L. anisa, L. bozemanii, L. dumoffii, L. fairfieldensis, L. gormanii, L. jordanis, L. maceachernii, L. micdadei, L. pneumophila subspp. fraseri and L. pneumophila subspp. pasculleii, and developed a rapid oligonucleotide microarray detection technique accordingly to identify 12 most common Legionella spp., which consist of 11 pathogenic species of L. anisa, L. bozemanii, L. dumoffii, L. gormanii, L. jordanis, L. longbeachae, L. maceachernii, L. micdadei, and L. pneumophila (including subspp. pneumophila, subspp. fraseri, and subspp. pasculleii and one non-pathogenic species, L. fairfieldensis. Twenty-nine probes that reproducibly detected multiple Legionella species with high specificity were included in the array. A total of 52 strains, including 30 target pathogens and 22 non-target bacteria, were used to verify the oligonucleotide microarray assay. The sensitivity of the detection was at 1.0 ng with genomic DNA or 13 CFU/100 mL with Legionella cultures. The microarray detected seven samples of air conditioner-condensed water with 100% accuracy, validating the technique as a promising method for applications in basic microbiology, clinical diagnosis, food safety, and epidemiological surveillance. The phylogenetic study based on the ITS has also revealed that the non-pathogenic L. fairfieldensis is the closest to L. pneumophila than the nine other pathogenic Legionella spp.

  15. A New Oligonucleotide Microarray for Detection of Pathogenic and Non-Pathogenic Legionella spp.

    Science.gov (United States)

    Cao, Boyang; Liu, Xiangqian; Yu, Xiang; Chen, Min; Feng, Lu; Wang, Lei

    2014-01-01

    Legionella pneumophila has been recognized as the major cause of legionellosis since the discovery of the deadly disease. Legionella spp. other than L. pneumophila were later found to be responsible to many non-pneumophila infections. The non-L. pneumophila infections are likely under-detected because of a lack of effective diagnosis. In this report, we have sequenced the 16S-23S rRNA gene internal transcribed spacer (ITS) of 10 Legionella species and subspecies, including L. anisa, L. bozemanii, L. dumoffii, L. fairfieldensis, L. gormanii, L. jordanis, L. maceachernii, L. micdadei, L. pneumophila subspp. fraseri and L. pneumophila subspp. pasculleii, and developed a rapid oligonucleotide microarray detection technique accordingly to identify 12 most common Legionella spp., which consist of 11 pathogenic species of L. anisa, L. bozemanii, L. dumoffii, L. gormanii, L. jordanis, L. longbeachae, L. maceachernii, L. micdadei, and L. pneumophila (including subspp. pneumophila, subspp. fraseri, and subspp. pasculleii) and one non-pathogenic species, L. fairfieldensis. Twenty-nine probes that reproducibly detected multiple Legionella species with high specificity were included in the array. A total of 52 strains, including 30 target pathogens and 22 non-target bacteria, were used to verify the oligonucleotide microarray assay. The sensitivity of the detection was at 1.0 ng with genomic DNA or 13 CFU/100 mL with Legionella cultures. The microarray detected seven samples of air conditioner-condensed water with 100% accuracy, validating the technique as a promising method for applications in basic microbiology, clinical diagnosis, food safety, and epidemiological surveillance. The phylogenetic study based on the ITS has also revealed that the non-pathogenic L. fairfieldensis is the closest to L. pneumophila than the nine other pathogenic Legionella spp. PMID:25469776

  16. NeisseriaBase: a specialised Neisseria genomic resource and analysis platform

    OpenAIRE

    Wenning Zheng; Naresh V.R. Mutha; Hamed Heydari; Avirup Dutta; Cheuk Chuen Siow; Nicholas S. Jakubovics; Wei Yee Wee; Shi Yang Tan; Mia Yang Ang; Guat Jah Wong; Siew Woh Choo

    2016-01-01

    Background. The gram-negative Neisseria is associated with two of the most potent human epidemic diseases: meningococcal meningitis and gonorrhoea. In both cases, disease is caused by bacteria colonizing human mucosal membrane surfaces. Overall, the genus shows great diversity and genetic variation mainly due to its ability to acquire and incorporate genetic material from a diverse range of sources through horizontal gene transfer. Although a number of databases exist for the Neisseria genome...

  17. Exposure to a widespread non-pathogenic bacterium magnifies sublethal pesticide effects in the damselfly Enallagma cyathigerum: From the suborganismal level to fitness-related traits

    International Nuclear Information System (INIS)

    Janssens, Lizanne; Stoks, Robby

    2013-01-01

    While there is increasing concern that pesticide stress can interact with stress imposed by antagonistic species including pathogens, it is unknown whether this also holds for non-pathogenic bacteria. We exposed Enallagma cyathigerum damselfly larvae to the pesticide chlorpyrifos and a non-pathogenic Escherichia coli strain. Both exposure to chlorpyrifos and E. coli reduced growth rate and fat storage, probably due to the observed energetically costly increases in physiological defence (glutathione-S-transferase and Hsp70) and, for E. coli, immune defence (phenoloxidase). Moreover, these stressors interacted for both fitness-related traits. Most importantly, another fitness-related trait, bacterial load, increased drastically with chlorpyrifos concentration. A possible explanation is that the upregulation of phenoloxidase in the presence of E. coli changed into a downregulation when combined with chlorpyrifos. We argue that the observed interactive, partly synergistic effects between pesticides and widespread non-pathogenic bacteria may be common and deserves further attention to improve ecological risk assessment of pesticides. -- Highlights: ► Non-pathogens such as the bacterium E. coli are ignored in ecotoxicology. ► Both E. coli and chlorpyrifos impaired fitness-related traits in damselfly larvae. ► E. coli modulated and magnified effects of chlorpyrifos on physiology and fitness. ► Bacterial load was magnified >10× in the presence of chlorpyrifos. ► Risk assessment of pesticides should consider synergisms with non-pathogens. -- Non-pathogenic bacteria reduce fitness-related traits and can synergistically interact with sublethal pesticide effects for physiological and fitness-related traits

  18. Trehalolipid biosurfactants from nonpathogenic Rhodococcus actinobacteria with diverse immunomodulatory activities.

    Science.gov (United States)

    Kuyukina, Maria S; Ivshina, Irena B; Baeva, Tatiana A; Kochina, Olesia A; Gein, Sergey V; Chereshnev, Valery A

    2015-12-25

    Actinobacteria of the genus Rhodococcus produce trehalolipid biosurfactants with versatile biochemical properties and low toxicity. In recent years, these biosurfactants are increasingly studied as possible biomedical agents with expressed immunological activities. Applications of trehalolipids from Rhodococcus, predominantly cell-bound, in biomedicine are also attractive because their cost drawback could be less significant for high-value products. The review summarizes recent findings in immunomodulatory activities of trehalolipid biosurfactants from nonpathogenic Rhodococcus and related actinobacteria and compares their biomedical potential with well-known immunomodifying properties of trehalose dimycolates from Mycobacterium tuberculosis. Molecular mechanisms of trehalolipid interactions with immunocompetent cells are also discussed. Copyright © 2015. Published by Elsevier B.V.

  19. A genetic screen reveals a periplasmic copper chaperone required for nitrite reductase activity in pathogenic Neisseria.

    Science.gov (United States)

    Jen, Freda E-C; Djoko, Karrera Y; Bent, Stephen J; Day, Christopher J; McEwan, Alastair G; Jennings, Michael P

    2015-09-01

    Under conditions of low oxygen availability, Neisseria meningitidis and Neisseria gonorrhoeae are able to respire via a partial denitrification pathway in which nitrite is converted to nitrous oxide. In this process, nitrite reductase (AniA), a copper (Cu)-containing protein converts nitrite to NO, and this product is converted to nitrous oxide by nitric oxide reductase (NorB). NorB also confers protection against toxic NO, and so we devised a conditional lethal screen, using a norB mutant, to identify mutants that were resistant to nitrite-dependent killing. After random-deletion mutagenesis of N. meningitidis, this genetic screen identified a gene encoding a Cu chaperone that is essential for AniA function, AccA. Purified AccA binds one Cu (I) ion and also possesses a second binding site for Cu (II). This novel periplasmic Cu chaperone (AccA) appears to be essential for provision of Cu ions to AniA of pathogenic Neisseria to generate an active nitrite reductase. Apart from the Neisseria genus, AccA is distributed across a wide range of environmental Proteobacteria species. © FASEB.

  20. Nucleotide sequence composition and method for detection of neisseria gonorrhoeae

    International Nuclear Information System (INIS)

    Lo, A.; Yang, H.L.

    1990-01-01

    This patent describes a composition of matter that is specific for Neisseria gonorrhoeae. It comprises: at least one nucleotide sequence for which the ratio of the amount of the sequence which hybridizes to chromosomal DNA of Neisseria gonorrhoeae to the amount of the sequence which hybridizes to chromosomal DNA of Neisseria meningitidis is greater than about five. The ratio being obtained by a method described

  1. Nucleotide sequence composition and method for detection of neisseria gonorrhoeae

    Energy Technology Data Exchange (ETDEWEB)

    Lo, A.; Yang, H.L.

    1990-02-13

    This patent describes a composition of matter that is specific for {ital Neisseria gonorrhoeae}. It comprises: at least one nucleotide sequence for which the ratio of the amount of the sequence which hybridizes to chromosomal DNA of {ital Neisseria gonorrhoeae} to the amount of the sequence which hybridizes to chromosomal DNA of {ital Neisseria meningitidis} is greater than about five. The ratio being obtained by a method described.

  2. In vitro antimycobacterial activity and toxicity of eight medicinal plants against pathogenic and nonpathogenic mycobacterial strains.

    Science.gov (United States)

    Nguta, Joseph M; Appiah-Opong, Regina; Nyarko, Alexander K; Yeboah-Manu, Dorothy; Addo, Phyllis G A; Otchere, Isaac Darko; Kissi-Twum, Abena

    2016-12-01

    Tuberculosis (TB) caused by Mycobacterium tuberculosis remains a serious public health challenge towards which new hits are urgently needed. Medicinal plants remains a major source of new ligands against global infectious illnesses. In our laboratories, we are currently investigating locally used ethnobotanicals for novel compounds against zoonotic tuberculosis. The microplate alamar blue assay (MABA) was used to study the anti-TB activity while the CellTiter 96® AQ ueous Assay, which is composed of solutions of a novel tetrazolium compound [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt; MTS] and an electron coupling reagent (phenazine methosulfate) PMS, was used for cytotoxic studies. Correlation coefficients (R 2 ) were used to compare the relationship between antimycobacterial activity of the eight crude extracts against nonpathogenic strains and the pathogenic Mycobacterium bovis. Minimum inhibitory concentration (MICs) values indicated that all the eight tested medicinal plant species had activity against all the three tested mycobacterial strains. Minimum inhibitory concentration value as low as 19.5µg/mL was observed against non-pathogenic strains M. bovis. Activity of the crude extracts against M. aurum was the best predictor of natural product activity against the pathogenic Mycobacterium bovis strain, with a correlation coefficient value (R 2 ) of 0.1371. Results obtained from the current study validate, in part, the traditional utilization of the tested medicinal plants against tuberculosis. The unripe fruits from Solanum torvum are a potential source of safe and efficacious anti-TB crude drugs as well as a source for natural compounds that act as new anti-infection agents, and thus deserve further investigation towards development of a new class of molecules with activity against sensitive and drug resistant strains of M. bovis. Copyright © 2016.

  3. In vitro antimycobacterial activity and toxicity of eight medicinal plants against pathogenic and nonpathogenic mycobacterial strains

    Directory of Open Access Journals (Sweden)

    Joseph M Nguta

    2016-01-01

    Full Text Available Tuberculosis (TB caused by Mycobacterium tuberculosis remains a serious public health challenge towards which new hits are urgently needed. Medicinal plants remains a major source of new ligands against global infectious illnesses. In our laboratories, we are currently investigating locally used ethnobotanicals for novel compounds against zoonotic tuberculosis. The microplate alamar blue assay (MABA was used to study the anti-TB activity while the CellTiter 96® AQueous Assay, which is composed of solutions of a novel tetrazolium compound [3-(4,5-dimethylthiazol-2-yl-5-(3-carboxymethoxyphenyl-2-(4-sulfophenyl-2H-tetrazolium, inner salt; MTS] and an electron coupling reagent (phenazine methosulfate PMS, was used for cytotoxic studies. Correlation coefficients (R2 were used to compare the relationship between antimycobacterial activity of the eight crude extracts against nonpathogenic strains and the pathogenic Mycobacterium bovis. Minimum inhibitory concentration (MICs values indicated that all the eight tested medicinal plant species had activity against all the three tested mycobacterial strains. Minimum inhibitory concentration value as low as 19.5 μg/mL was observed against non-pathogenic strains M. bovis. Activity of the crude extracts against M. aurum was the best predictor of natural product activity against the pathogenic Mycobacterium bovis strain, with a correlation coefficient value (R2 of 0.1371. Results obtained from the current study validate, in part, the traditional utilization of the tested medicinal plants against tuberculosis. The unripe fruits from Solanum torvum are a potential source of safe and efficacious anti-TB crude drugs as well as a source for natural compounds that act as new anti-infection agents, and thus deserve further investigation towards development of a new class of molecules with activity against sensitive and drug resistant strains of M. bovis.

  4. Structural alterations in a component of cytochrome c oxidase and molecular evolution of pathogenic Neisseria in humans.

    Directory of Open Access Journals (Sweden)

    Marina Aspholm

    2010-08-01

    Full Text Available Three closely related bacterial species within the genus Neisseria are of importance to human disease and health. Neisseria meningitidis is a major cause of meningitis, while Neisseria gonorrhoeae is the agent of the sexually transmitted disease gonorrhea and Neisseria lactamica is a common, harmless commensal of children. Comparative genomics have yet to yield clear insights into which factors dictate the unique host-parasite relationships exhibited by each since, as a group, they display remarkable conservation at the levels of nucleotide sequence, gene content and synteny. Here, we discovered two rare alterations in the gene encoding the CcoP protein component of cytochrome cbb(3 oxidase that are phylogenetically informative. One is a single nucleotide polymorphism resulting in CcoP truncation that acts as a molecular signature for the species N. meningitidis. We go on to show that the ancestral ccoP gene arose by a unique gene duplication and fusion event and is specifically and completely distributed within species of the genus Neisseria. Surprisingly, we found that strains engineered to express either of the two CcoP forms conditionally differed in their capacity to support nitrite-dependent, microaerobic growth mediated by NirK, a nitrite reductase. Thus, we propose that changes in CcoP domain architecture and ensuing alterations in function are key traits in successive, adaptive radiations within these metapopulations. These findings provide a dramatic example of how rare changes in core metabolic proteins can be connected to significant macroevolutionary shifts. They also show how evolutionary change at the molecular level can be linked to metabolic innovation and its reversal as well as demonstrating how genotype can be used to infer alterations of the fitness landscape within a single host.

  5. Comparative genome analysis of pathogenic and non-pathogenic Clavibacter strains reveals adaptations to their lifestyle

    OpenAIRE

    Załuga, Joanna; Stragier, Pieter; Baeyen, Steve; Haegeman, Annelies; Van Vaerenbergh, Johan; Maes, Martine; De Vos, Paul

    2014-01-01

    Background The genus Clavibacter harbors economically important plant pathogens infecting agricultural crops such as potato and tomato. Although the vast majority of Clavibacter strains are pathogenic, there is an increasing number of non-pathogenic isolates reported. Non-pathogenic Clavibacter strains isolated from tomato seeds are particularly problematic because they affect the current detection and identification tests for Clavibacter michiganensis subsp. michiganensis (Cmm), which is reg...

  6. Targeting solid tumors with non-pathogenic obligate anaerobic bacteria.

    Science.gov (United States)

    Taniguchi, Shun'ichiro; Fujimori, Minoru; Sasaki, Takayuki; Tsutsui, Hiroko; Shimatani, Yuko; Seki, Keiichi; Amano, Jun

    2010-09-01

    Molecular-targeting drugs with fewer severe adverse effects are attracting great attention as the next wave of cancer treatment. There exist, however, populations of cancer cells resistant to these drugs that stem from the instability of tumor cells and/or the existence of cancer stem cells, and thus specific toxicity is required to destroy them. If such selectivity is not available, these targets may be sought out not by the cancer cell types themselves, but rather in their adjacent cancer microenvironments by means of hypoxia, low pH, and so on. The anaerobic conditions present in malignant tumor tissues have previously been regarded as a source of resistance in cancer cells against conventional therapy. However, there now appears to be a way to make use of these limiting factors as a selective target. In this review, we will refer to several trials, including our own, to direct attention to the utilizable anaerobic conditions present in malignant tumor tissues and the use of bacteria as carriers to target them. Specifically, we have been developing a method to attack solid cancers using the non-pathogenic obligate anaerobic bacterium Bifidobacterium longum as a vehicle to selectively recognize and target the anaerobic conditions in solid cancer tissues. We will also discuss the existence of low oxygen pressure in tumor masses in spite of generally enhanced angiogenesis, overview current cancer therapies, especially the history and present situation of bacterial utility to treat solid tumors, and discuss the rationality and future possibilities of this novel mode of cancer treatment. © 2010 Japanese Cancer Association.

  7. Neisseria meningitidis serogroup A capsular polysaccharide acetyltransferase, methods and compositions

    Energy Technology Data Exchange (ETDEWEB)

    Stephens, David S [Stone Mountain, GA; Gudlavalleti, Seshu K [Kensington, MD; Tzeng, Yih-Ling [Atlanta, GA; Datta, Anup K [San Diego, CA; Carlson, Russell W [Athens, GA

    2011-02-08

    Provided are methods for recombinant production of an O-acetyltransferase and methods for acetylating capsular polysaccharides, especially those of a Serogroup A Neisseria meningitidis using the recombinant O-acetyltransferase, and immunogenic compositions comprising the acetylated capsular polysaccharide.

  8. Recruitment of a penicillin-binding protein gene from Neisseria flavescens during the emergence of penicillin resistance in Neisseria meningitidis

    OpenAIRE

    SPRATT, BG; ZHANG, QY; JONES, DM; HUTCHISON, A; BRANNIGAN, JA; DOWSON, CG

    1989-01-01

    Non-beta-lactamase-producing, penicillin-resistant strains of Neisseria meningitidis produce altered forms of penicillin-binding protein 2 that have decreased affinity for penicillin. The sequence of the penicillin-binding protein 2 gene (penA) from a penicillin-resistant strain of N. meningitidis was compared to the sequence of the same gene from penicillin-sensitive strains and from penicillin-sensitive and penicillin-resistant strains of Neisseria gonorrhoeae. The penA genes from penicilli...

  9. INFEKSI NEISSERIA GONORRHOEAE AKIBAT SEXUAL ABUSE PADA SEORANG ANAK PEREMPUAN

    Directory of Open Access Journals (Sweden)

    Satya Wydya Yenny

    2008-09-01

    Full Text Available AbstrakInfeksi Neisseria gonorrhoeae pada anak akibat sexual abuse sangat jarang dilaporkan.Dilaporkan satu kasus infeksi Neisseria gonorrhoeae pada seorang anak perempuan usia 6 tahun setelah mengalami sexual abuse satu minggu yang lalu.Diagnosis ditegakkan berdasarkan anamnesis, pemeriksaan klinis dan pemeriksaan laboratorium. Anamnesis adanya keputihan sejak 5 hari sebelum berobat. Pada pemeriksaan fisis tampak cairan berwarna krem menempel pada celana dalam, cukup banyak, serta sedikit kemerahan dan duh genital pada vulva. Hasil pemeriksaan mikroskopis ditemukan diplokokus Gram negatif dan kultur didapatkan Neisseria gonorrhoeae. Berdasarkan hasil tes sensitivitas, pasien diterapi dengan ceftriaxon 125 mg i.m, dosis tunggal dan memberikan kesembuhan.Infeksi ini membutuhkan penatalaksanaan yang komprehensif karena mempunyai dampak psikologis baik bagi anak maupun keluarga seumur hidupKata kunci : Neisseria gonorrhoeae, sexual abuse, anakAbstractNeisseria gonorrhoe infection in childhood caused by sexual abuse is considered rare reported.A young girl 6 years old suffering gonococcal infection was reported. The diagnostic procedure were base on clinically and laboratory findings. The source of transmission was sexual abuse by an adult man. Physical examination revealed purulent discharge, cream in colour that stains the underwear with minimal vaginal discharge and vulval erythema. Laboratory examination showed Gram-negative diplococcic and isolation of Neisseria gonorrhoeae. This patient had been treated with ceftriaxon 125mg given intramuscularly in a single dose. Result of the treatment was good.The psychological sequelae of sexual abuse and the turmoil in the family produced by suspicions and allegations are largely unknown, but are probably life long.Keywords: Neisseria gonorrhoeae, sexual abuse, childLAPORAN

  10. Comparative genome analysis of pathogenic and non-pathogenic Clavibacter strains reveals adaptations to their lifestyle.

    Science.gov (United States)

    Załuga, Joanna; Stragier, Pieter; Baeyen, Steve; Haegeman, Annelies; Van Vaerenbergh, Johan; Maes, Martine; De Vos, Paul

    2014-05-22

    The genus Clavibacter harbors economically important plant pathogens infecting agricultural crops such as potato and tomato. Although the vast majority of Clavibacter strains are pathogenic, there is an increasing number of non-pathogenic isolates reported. Non-pathogenic Clavibacter strains isolated from tomato seeds are particularly problematic because they affect the current detection and identification tests for Clavibacter michiganensis subsp. michiganensis (Cmm), which is regulated with a zero tolerance in tomato seed. Their misidentification as pathogenic Cmm hampers a clear judgment on the seed quality and health. To get more insight in the genetic features linked to the lifestyle of these bacteria, a whole-genome sequence of the tomato seed-borne non-pathogenic Clavibacter LMG 26808 was determined. To gain a better understanding of the molecular determinants of pathogenicity, the genome sequence of LMG 26808 was compared with that of the pathogenic Cmm strain (NCPPB 382). The comparative analysis revealed that LMG 26808 does not contain plasmids pCM1 and pCM2 and also lacks the majority of important virulence factors described so far for pathogenic Cmm. This explains its apparent non-pathogenic nature in tomato plants. Moreover, the genome analysis of LMG 26808 detected sequences from a plasmid originating from a member of Enterobacteriaceae/Klebsiella relative. Genes received that way and coding for antibiotic resistance may provide a competitive advantage for survival of LMG 26808 in its ecological niche. Genetically, LMG 26808 was the most similar to the pathogenic Cmm NCPPB 382 but contained more mobile genetic elements. The genome of this non-pathogenic Clavibacter strain contained also a high number of transporters and regulatory genes. The genome sequence of the non-pathogenic Clavibacter strain LMG 26808 and the comparative analyses with other pathogenic Clavibacter strains provided a better understanding of the genetic bases of virulence and

  11. Diagnosis of Neisseria gonorrhoeae Using Molecular Beacon

    Science.gov (United States)

    Patel, Achchhe Lal; Sonkar, Subash Chandra; Kumari, Indu; Saluja, Daman

    2015-01-01

    Neisseria gonorrhoeae is an important sexually transmitted diseases (STD) causing pathogen worldwide. Due to absence of an affordable diagnostic assay, routine screening of gonococcal infection becomes impossible in developing countries where infection rates are maximum. Treatment is given on the basis of symptoms alone which leads to spread of infection. Thus, development of a rapid, sensitive, specific, and PCR based visual diagnostic assay suitable for developing countries, required for better disease management, is aimed at in present study. Endocervical swabs were collected from patients visiting gynecology department of various hospitals in Delhi. In-house PCR based assay was developed and modified to visual assay using molecular beacon for end-point detection. It was evaluated against Roche AMPLICOR NG kit and rmp gene. Specificity of beacon was confirmed by competition experiments. Diagnostic test was 98.21% specific and 99.59% sensitive whereas negative and positive predicted value were 99.40% and 98.78%, respectively. We also observed that twice the concentration (2X) of premix was stable at 4°C for 4 months and dry swab samples gave concordant results with that of wet swabs. These features make the test best suitable for routine diagnosis of genital infections in developing countries. PMID:25802857

  12. Metabolism and virulence in Neisseria meningitidis

    Directory of Open Access Journals (Sweden)

    Christoph eSchoen

    2014-08-01

    Full Text Available A longstanding question in infection biology addresses the genetic basis for invasive behaviour in commensal pathogens. A prime example for such a pathogen is Neisseria meningitidis. On the one hand it is a harmless commensal bacterium exquisitely adapted to humans, and on the other hand it sometimes behaves like a ferocious pathogen causing potentially lethal disease such as sepsis and acute bacterial meningitis. Despite the lack of a classical repertoire of virulence genes in N. meningitidis separating commensal from invasive strains, molecular epidemiology suggests that carriage and invasive strains belong to genetically distinct populations. In recent years, it has become increasingly clear that metabolic adaptation enables meningococci to exploit host resources, supporting the concept of nutritional virulence as a crucial determinant of invasive capability. Here, we discuss the contribution of core metabolic pathways in the context of colonization and invasion with special emphasis on results from genome-wide surveys. The metabolism of lactate, the oxidative stress response, and, in particular, glutathione metabolism as well as the denitrification pathway provide examples of how meningococcal metabolism is intimately linked to pathogenesis. We further discuss evidence from genome-wide approaches regarding potential metabolic differences between strains from hyperinvasive and carriage lineages and present new data assessing in vitro growth differences of strains from these two populations. We hypothesize that strains from carriage and hyperinvasive lineages differ in the expression of regulatory genes involved particularly in stress responses and amino acid metabolism under infection conditions.

  13. Co-occurrence of pathogenic and non-pathogenic Fusarium decemcellulare and Lasiodiplodia theobromae isolates in cushion galls disease of cacao (Theobroma cacao L.

    Directory of Open Access Journals (Sweden)

    Castillo Daynet Sosa del

    2016-04-01

    Full Text Available Flowery cushion gall of cacao is a disease complex with six types. Fusarium decemcellulare have been isolated from both flowery and green point galls and recognized as the etiological agent of the disease. In the present work we: i identified by ITS-rDNA sequencing and/or taxonomy the cultivable fungal species or Operative Taxonomic Units (OTUs associated with the five symptoms of cushion galls in cacao from Venezuela, and ii determined the gall inducing capacity on cacao peeled seeds after 45 days of inoculation with suspensions of mycelia/ spores from distinct isolate types. The whole isolate collection rendered an abundance of 113 isolates with a richness of 39 OTUs (27 and eight identified at the species or genera levels, respectively, and in unidentified fungi. The dominant recovered species (≈36% were F. decemcellulare and Lasiodiplodia theobromae. Some isolates of F. decemcellulare, L. theobromae, F. equiseti, Fusarium spp., F. solani, F. incarnatum, Rhizocthonia solani and Penicillium sp. were pathogenic. Some other isolates of the first six mentioned taxa behave as non-pathogenic. Furthermore, pathogenic and non-pathogenic isolates can also co-occur within a single plant and gall type. Moreover, 2-5 species within a single gall symptom in a single tree were identified (not necessarily at the same point in the tree, indicating a broad diversity of co-occurring taxa.

  14. Differentiation between a pathogenic and a non-pathogenic form of Gyrodactylus salaris using PCR-RFLP

    DEFF Research Database (Denmark)

    Kania, Per Walther; Jørgensen, Thomas Rohde; Buchmann, Kurt

    2007-01-01

    A new method based on PCR-RFLP is presented. It is able to differentiate between the Danish non-pathogenic form of Gyrodactylus salaris and the Norwegian pathogenic form.......A new method based on PCR-RFLP is presented. It is able to differentiate between the Danish non-pathogenic form of Gyrodactylus salaris and the Norwegian pathogenic form....

  15. Nanostructured platform for the detection of Neisseria gonorrhoeae using electrochemical impedance spectroscopy and differential pulse voltammetry

    International Nuclear Information System (INIS)

    Singh, R.; Matharu, Z.; Srivastava, A.K.; Sood, S.; Gupta, R.K.; Malhotra, B.D.

    2012-01-01

    We report on a nanocomposite based genosensor for the detection of Neisseria gonorrhoeae, a bacterium causing the sexually transmitted disease gonorrhoea. Amino-labeled probe DNA was covalently immobilized on electrochemically prepared polyaniline and iron oxide (PANI-Fe 3 O 4 ) nanocomposite film on an indium tin oxide (ITO) electrode. Scanning electron microscopy, transmission electron microscopy, electrochemical impedance spectroscopy (EIS) and differential pulse voltammetry (DPV) techniques have been employed to characterize surface of the modified electrode. The genosensor has detection limits of 1 x 10 -15 M and 1 x 10 -17 M, respectively, using the EIS and DPV techniques. This biosensor can discriminate a complementary sequence from a single-base mismatch and from non-complementary DNA, and has been utilized for detection of DNA extracted from N. gonorrhoeae culture, and from patient samples with N. gonorrhoeae. It is found to exhibit good specificity for N. gonorrhoeae species and shows no response towards non-gonorrhoeae type of Neisseria species (NgNs) and other gram-negative bacterias (GNBs). The affinity constant for hybridization calculated using the Langmuir adsorption isotherm model is found to be 3. 39 x 10 8 M -1 . (author)

  16. Reinforcing effects of non-pathogenic bacteria and predation risk: from physiology to life history.

    Science.gov (United States)

    Janssens, Lizanne; Stoks, Robby

    2014-10-01

    The important ecological role of predation risk in shaping populations, communities and ecosystems is becoming increasingly clear. In this context, synergistic effects between predation risk and other natural stressors on prey organisms are gaining attention. Although non-pathogenic bacteria can be widespread in aquatic ecosystems, their role in mediating effects of predation risk has been ignored. We here address the hypothesis that non-pathogenic bacteria may reinforce the negative effects of predation risk in larvae of the damselfly Coenagrion puella. We found synergistic effects for all three life history variables studied: mortality increased, growth reductions were magnified and bacterial load was higher when both non-lethal stressors were combined. The combined exposure to the bacterium and predation risk considerably impaired the two key antipredator mechanisms of the damselfly larvae: they no longer reduced their food intake under predation risk and showed a synergistic reduction in escape swimming speed. The reinforcing negative effects on the fitness-related traits could be explained by the observed synergistic effects on food intake, swimming muscle mass, immune function and oxidative damage. These are likely widespread consequences of energetic constraints and increased metabolic rates associated with the fight-or-flight response. We therefore hypothesize that the here documented synergistic interactions with non-pathogenic bacteria may be widespread. Our results highlight the ignored ecological role of non-pathogenic bacteria in reinforcing the negative effects of predation risk on prey organisms.

  17. Nonprogressing HIV-infected children share fundamental immunological features of nonpathogenic SIV infection

    DEFF Research Database (Denmark)

    Muenchhoff, Maximilian; Adland, Emily; Karimanzira, Owen

    2016-01-01

    nonprogressors. These children therefore express two cardinal immunological features of nonpathogenic SIV infection in sooty mangabeys-low immune activation despite high viremia and low CCR5 expression on long-lived central memory CD4 T cells-suggesting closer similarities with nonpathogenetic mechanisms evolved...

  18. Genetic transformation of Neisseria gonorrhoeae shows a strand preference

    OpenAIRE

    Duffin, Paul M.; Seifert, H. Steven

    2012-01-01

    Natural transformation is the main means of horizontal genetic exchange in the obligate human pathogen Neisseria gonorrhoeae. Neisseria spp. have been shown to preferentially take up and transform their own DNA by recognizing a non-palindromic 10 or 12 nucleotide DNA uptake sequence (DUS10 or DUS12). We investigated the ability of the DUS12 to enhance single-stranded DNA (ssDNA) transformation. Given the non-palindromic nature of the DUS12, we tested whether both strands of the DUS equally en...

  19. Antimicrobial blue light inactivation of Neisseria gonorrhoeae

    Science.gov (United States)

    Wang, Ying; Gu, Ying; Dai, Tianhong

    2018-02-01

    Neisseria gonorrhoeae is a human-adapted, gram-negative diplococcus that infects human reproductive tracts and causes gonorrhea, a sexually transmitted disease, resulting in discharge and inflammation at the urethra, cervix, pharynx, or rectum. Over the years, N. gonorrhoeae has developed resistance to nearly every drug ever used to treat it, including sulfonamides, penicillin, tetracycline, and fluoroquinolones. Drug-resistant N. gonorrhoeae is now considered by the Centers for Disease Control and Prevention (CDC) as an urgent threat. The present study aimed to evaluate the efficacy of antimicrobial blue light (aBL) at 405 and 470 nm for inactivating N. gonorrhoeae and reveal the mechanism of action. Our results showed that an exposure of 45 J/cm2 aBL at 405 nm reduced the bacterial CFU by 7.16-log10. When the aBL exposure was increased to 54 J/cm2, eradication of bacterial CFU was achieved. When the bacteria were exposed to aBL at 470 nm, 3-log10 reduction of CFU was observed at an aBL exposure of higher than 126 J/cm2. Absorption and fluorescence spectroscopic analyses revealed the presence of endogenous porphyrins and flavins in N. gonorrhoeae cells. The present study indicated that aBL is a potential strategy to control N. gonorrhoeae infections. Endogenous porphyrins play a vital role in the killing effects of aBL. In vivo experiments are ongoing in our laboratory to treat genital tract infections in mice using aBL and explore the potential clinical applications.

  20. Outbreak of serotype W135 Neisseria meningitidis in central river ...

    African Journals Online (AJOL)

    2012-06-21

    Jun 21, 2012 ... program on immunization schedule of the Gambia and other countries within the meningitic epidemic belt. Key words: Neisseria ... The African meningitis belt extends from Ethiopia in the. East, to Senegal in the West within ..... surveillance and management system at the national level for effective control of ...

  1. Carriage rate of Neisseria meningitides among pupils of islamic ...

    African Journals Online (AJOL)

    The study was a cross-sectional study that determined the carriage rate of Neisseria meningitides among pupils of Islamic boarding schools (Tsangaya Almajirai) in Kano, Nigeria. Nasal swabs were randomly collected from 150 children aged 5 years to 10 years and above from three selected Tsangaya Almajiri schools in ...

  2. Oligo-DNA custom macroarray for monitoring major pathogenic and non-pathogenic fungi and bacteria in the phyllosphere of apple trees.

    Science.gov (United States)

    He, Ying-Hong; Isono, Sayaka; Shibuya, Makoto; Tsuji, Masaharu; Adkar Purushothama, Charith-Raj; Tanaka, Kazuaki; Sano, Teruo

    2012-01-01

    To monitor the richness in microbial inhabitants in the phyllosphere of apple trees cultivated under various cultural and environmental conditions, we developed an oligo-DNA macroarray for major pathogenic and non-pathogenic fungi and bacteria inhabiting the phyllosphere of apple trees. First, we isolated culturable fungi and bacteria from apple orchards by an agar-plate culture method, and detected 32 fungal and 34 bacterial species. Alternaria, Aureobasidium, Cladosporium, Rhodotorula, Cystofilobasidium, and Epicoccum genera were predominant among the fungi, and Bacillus, Pseudomonas, Sphingomonas, Methylobacterium, and Pantoea genera were predominant among the bacteria. Based on the data, we selected 29 major non-pathogenic and 12 phytopathogenic fungi and bacteria as the targets of macroarray. Forty-one species-specific 40-base pair long oligo-DNA sequences were selected from the nucleotide sequences of rDNA-internal transcribed spacer region for fungi and 16S rDNA for bacteria. The oligo-DNAs were fixed on nylon membrane and hybridized with digoxigenin-labeled cRNA probes prepared for each species. All arrays except those for Alternaria, Bacillus, and their related species, were specifically hybridized. The array was sensitive enough to detect 10(3) CFU for Aureobasidium pullulans and Bacillus cereus. Nucleotide sequencing of 100 each of independent fungal rDNA-ITS and bacterial 16S-rDNA sequences from apple tree was in agreement with the macroarray data obtained using the same sample. Finally, we analyzed the richness in the microbial inhabitants in the samples collected from apple trees in four orchards. Major apple pathogens that cause scab, Alternaria blotch, and Marssonina blotch were detected along with several non-phytopathogenic fungal and bacterial inhabitants. The macroarray technique presented here is a strong tool to monitor the major microbial species and the community structures in the phyllosphere of apple trees and identify key species

  3. Lectins discriminate between pathogenic and nonpathogenic South American trypanosomes

    International Nuclear Information System (INIS)

    de Miranda Santos, I.K.; Pereira, M.E.

    1984-01-01

    Cell surface carbohydrates of Trypanosoma cruzi, Trypanosoma rangeli, and Trypanosoma conorhini were analyzed by a micro-agglutination assay employing 27 highly purified lectins and by binding assays using various 125 I-labeled lectins. The following seven lectins discriminated between the trypanosomes: 1) tomato lectin (an N-acetyl-D-glucosamine-binding protein), both in purified form and as crude tomato juice; 2) Bauhinea purpurea and Sophora japonica lectins (both N-acetyl-D-galactosamine-binding proteins), which selectively agglutinated T. cruzi; 3) Vicia villosa (an N-acetyl-D-galactosamine-binding protein) which was specific for T. rangeli; 4) peanut lectin (a D-galactose-binding protein) both in purified form and as crude saline extract; and 5) Ulex europaeus and Lotus tetragonolobus (both L-fucose-binding proteins) lectins which reacted only with T. conorhini. Binding studies with 125I-labeled lectins were performed to find whether unagglutinated cells of the three different species of trypanosomes might have receptors for these lectins, in which case absence of agglutination could be due to a peculiar arrangement of the receptors. These assays essentially confirmed the agglutination experiments

  4. Lectins discriminate between pathogenic and nonpathogenic South American trypanosomes

    Energy Technology Data Exchange (ETDEWEB)

    de Miranda Santos, I.K.; Pereira, M.E.

    1984-09-01

    Cell surface carbohydrates of Trypanosoma cruzi, Trypanosoma rangeli, and Trypanosoma conorhini were analyzed by a micro-agglutination assay employing 27 highly purified lectins and by binding assays using various /sup 125/I-labeled lectins. The following seven lectins discriminated between the trypanosomes: 1) tomato lectin (an N-acetyl-D-glucosamine-binding protein), both in purified form and as crude tomato juice; 2) Bauhinea purpurea and Sophora japonica lectins (both N-acetyl-D-galactosamine-binding proteins), which selectively agglutinated T. cruzi; 3) Vicia villosa (an N-acetyl-D-galactosamine-binding protein) which was specific for T. rangeli; 4) peanut lectin (a D-galactose-binding protein) both in purified form and as crude saline extract; and 5) Ulex europaeus and Lotus tetragonolobus (both L-fucose-binding proteins) lectins which reacted only with T. conorhini. Binding studies with 125I-labeled lectins were performed to find whether unagglutinated cells of the three different species of trypanosomes might have receptors for these lectins, in which case absence of agglutination could be due to a peculiar arrangement of the receptors. These assays essentially confirmed the agglutination experiments.

  5. Adjuvantes:Un componente esencial de las vacunas de Neisseria

    Directory of Open Access Journals (Sweden)

    Reinaldo Acevedo

    2009-08-01

    Full Text Available Adjuvants may be classified into delivery systems and immune potentiator or modulator molecules based on their mechanism of action. Neisseria vaccines containing traditional adjuvants such as aluminium salts have existed for long time, but meningitis caused by Neisseria meningitidis serogroups, particularly serogroup B, continues to be a global health problem. Novel strategies have applied in silico and recombinant technologies to develop "universal" antigens (e.g. proteins, peptides and plasmid DNA for vaccines, but these antigens have been shown to be poorly immunogenic even when alum adjuvanted, implying a need for better vaccine design. In this work we review the use of natural, detoxified, or synthetic molecules in combination with antigens to activate the innate immune system and to modulate the adaptive immune responses. In the main, antigenic and imune potentiator signals are delivered using nano-, micro-particles, alum, or emulsions. The importance of interaction between adjuvants and antigens to activate and target dendritic cells, the bridge between the innate and adaptive immune systems, will be discussed. In addition, nasal vaccine strategies based on the development of mucosal adjuvants and Neisseria derivatives to eliminate the pathogen at the site of infection provide promising adjuvants effective not only against respiratory pathogens, but also against pathogens responsible for enteric and sexually transmitted diseases.

  6. Role of penA polymorphisms for penicillin susceptibility in Neisseria lactamica and Neisseria meningitidis.

    Science.gov (United States)

    Karch, André; Vogel, Ulrich; Claus, Heike

    2015-10-01

    In meningococci, reduced penicillin susceptibility is associated with five specific mutations in the transpeptidase region of penicillin binding protein 2 (PBP2). We showed that the same set of mutations was present in 64 of 123 Neisseria lactamica strains obtained from a carriage study (MIC range: 0.125-2.0mg/L). The PBP2 encoding penA alleles in these strains were genetically similar to those found in intermediate resistant meningococci suggesting frequent interspecies genetic exchange. Fifty-six N. lactamica isolates with mostly lower penicillin MICs (range: 0.064-0.38mg/L) exhibited only three of the five mutations. The corresponding penA alleles were unique to N. lactamica and formed a distinct genetic clade. PenA alleles with no mutations on the other hand were unique to meningococci. Under penicillin selective pressure, genetic transformation of N. lactamica penA alleles in meningococci was only possible for alleles encoding five mutations, but not for those encoding three mutations; the transfer resulted in MICs comparable to those of meningococci harboring penA alleles that encoded PBP2 with five mutations, but considerably lower than those of the corresponding N. lactamica donor strains. Due to a transformation barrier the complete N. lactamica penA could not be transformed into N. meningitidis. In summary, penicillin MICs in N. lactamica were associated with the number of mutations in the transpeptidase region of PBP2. Evidence for interspecific genetic transfer was only observed for penA alleles associated with higher MICs, suggesting that alleles encoding only three mutations in the transpeptidase region are biologically not effective in N. meningitidis. Factors other than PBP2 seem to be responsible for the high levels of penicillin resistance in N. lactamica. A reduction of penicillin susceptibility in N. meningitidis by horizontal gene transfer from N. lactamica is unlikely to happen. Copyright © 2015 Elsevier GmbH. All rights reserved.

  7. Neisseria meningitidis Infecting a Prosthetic Knee Joint: A New Case of an Unusual Disease

    Directory of Open Access Journals (Sweden)

    Berta Becerril Carral

    2017-01-01

    Full Text Available Primary meningococcal meningitis is an infrequent but known disease. However, the infection of a prosthetic joint with Neisseria meningitidis is rare. We hereby describe the second case of an arthroplasty infected with Neisseria meningitidis that responded favourably to prosthesis retention with surgical debridement, in combination with antibiotics treatment.

  8. Use of restriction fragment length polymorphisms to investigate strain variation within Neisseria meningitidis

    Energy Technology Data Exchange (ETDEWEB)

    Williams, S.D.

    1989-01-01

    Similarity within bacterial populations is difficult to assess due to the limited number of characters available for evaluation and the heterogeneity of bacterial species. Currently, the preferred method used to evaluate the structure of bacterial populations is multilocus enzyme electrophoresis. However, this method is extremely cumbersome and only offers an indirect measure of genetic similarities. The development of a more direct and less cumbersome method for this purpose is warranted. Restriction fragment length polymorphism analysis was evaluated as a tool for use in the study of bacterial population structures and in the epidemiology and surveillance of infectious disease. A collection of Neisseria meningitidis was available for use in the investigation of this technique. Neisseria meningitidis is the causative agent of epidemic cerebrospinal meningitis and septicemia as well as a variety of other clinical manifestations. Each isolate in the collection was defined in terms of serogroup specificity, clinical history, geographic source, and date of isolation. Forty-six strains were chosen for this study. The DNA from each strain was restricted with Pst1 and EcoR1 and electrophoresed on agarose gels. The DNA was transferred to nylon filters and hybridized with P{sup 32} labeled DNA probes. Two randomly generated probes and a gene-specific probe were used to estimate the genetic similarities between and among the strains in the study population. A total of 28 different restriction fragment migration types were detected by the probes used. Data obtained from the RFLP analysis was analyzed by cluster analysis and multivariate statistical methods. A total of 7 clones groups were detected. Two of these appear to be major clones that comprise 35% of the population.

  9. Use of restriction fragment length polymorphisms to investigate strain variation within Neisseria meningitidis

    International Nuclear Information System (INIS)

    Williams, S.D.

    1989-01-01

    Similarity within bacterial populations is difficult to assess due to the limited number of characters available for evaluation and the heterogeneity of bacterial species. Currently, the preferred method used to evaluate the structure of bacterial populations is multilocus enzyme electrophoresis. However, this method is extremely cumbersome and only offers an indirect measure of genetic similarities. The development of a more direct and less cumbersome method for this purpose is warranted. Restriction fragment length polymorphism analysis was evaluated as a tool for use in the study of bacterial population structures and in the epidemiology and surveillance of infectious disease. A collection of Neisseria meningitidis was available for use in the investigation of this technique. Neisseria meningitidis is the causative agent of epidemic cerebrospinal meningitis and septicemia as well as a variety of other clinical manifestations. Each isolate in the collection was defined in terms of serogroup specificity, clinical history, geographic source, and date of isolation. Forty-six strains were chosen for this study. The DNA from each strain was restricted with Pst1 and EcoR1 and electrophoresed on agarose gels. The DNA was transferred to nylon filters and hybridized with P 32 labeled DNA probes. Two randomly generated probes and a gene-specific probe were used to estimate the genetic similarities between and among the strains in the study population. A total of 28 different restriction fragment migration types were detected by the probes used. Data obtained from the RFLP analysis was analyzed by cluster analysis and multivariate statistical methods. A total of 7 clones groups were detected. Two of these appear to be major clones that comprise 35% of the population

  10. Genome wide expression profiling reveals suppression of host defence responses during colonisation by Neisseria meningitides but not N. lactamica.

    Directory of Open Access Journals (Sweden)

    Hazel En En Wong

    Full Text Available Both Neisseria meningitidis and the closely related bacterium Neisseria lactamica colonise human nasopharyngeal mucosal surface, but only N. meningitidis invades the bloodstream to cause potentially life-threatening meningitis and septicaemia. We have hypothesised that the two neisserial species differentially modulate host respiratory epithelial cell gene expression reflecting their disease potential. Confluent monolayers of 16HBE14 human bronchial epithelial cells were exposed to live and/or dead N. meningitidis (including capsule and pili mutants and N. lactamica, and their transcriptomes were compared using whole genome microarrays. Changes in expression of selected genes were subsequently validated using Q-RT-PCR and ELISAs. Live N. meningitidis and N. lactamica induced genes involved in host energy production processes suggesting that both bacterial species utilise host resources. N. meningitidis infection was associated with down-regulation of host defence genes. N. lactamica, relative to N. meningitidis, initiates up-regulation of proinflammatory genes. Bacterial secreted proteins alone induced some of the changes observed. The results suggest N. meningitidis and N. lactamica differentially regulate host respiratory epithelial cell gene expression through colonisation and/or protein secretion, and that this may contribute to subsequent clinical outcomes associated with these bacteria.

  11. A new laboratory cultivation of Paramecium bursaria using non-pathogenic bacteria strains.

    Science.gov (United States)

    Bator, Tomasz

    2010-01-01

    In most studies dealing with the laboratory cultivation of paramecia (Paramecium bursaria), Klebsiella pneumoniae bacteria are used to inoculate the medium. However, Klebsiella pneumoniae is a typical pathogen, and its use is always associated with a risk of infection. The aim of the present research was to examine non-pathogenic bacteria strains as components of the medium for Paramecium bursaria. The paramecia were incubated on lettuce infusions bacterized with different bacteria strains: Bacillus subtilis DSM 10, Bacillus megaterium DSM 32, Escherichia coli DSM 498, Micrococcus luteus DSM 348. A strain derived from the natural habitat of Paramecium bursaria was used as the control one. Experiments were conducted under constant light and in the dark. Paramecia cells were counted under a stereomicroscope on consecutive days of incubation. The obtained results show that the most intensive growth of Paramecium bursaria occurs in the presence of Escherichia coli DSM 498. The use of this strain as a component of the medium allows one to obtain a high number of ciliates regardless of the light conditions. It can be concluded that the Paramecium bursaria cultivation procedure can be modified by using the non-pathogenic bacteria strain Escherichia coli DSM 498 instead of Klebsiella pneumoniae.

  12. Comparative proteomic analysis of pathogenic and non-pathogenic strains from the swine pathogen Mycoplasma hyopneumoniae

    Directory of Open Access Journals (Sweden)

    Klein Cátia S

    2009-12-01

    Full Text Available Abstract Background Mycoplasma hyopneumoniae is a highly infectious swine pathogen and is the causative agent of enzootic pneumonia (EP. Following the previous report of a proteomic survey of the pathogenic 7448 strain of swine pathogen, Mycoplasma hyopneumoniae, we performed comparative protein profiling of three M. hyopneumoniae strains, namely the non-pathogenic J strain and the two pathogenic strains 7448 and 7422. Results In 2DE comparisons, we were able to identify differences in expression levels for 67 proteins, including the overexpression of some cytoadherence-related proteins only in the pathogenic strains. 2DE immunoblot analyses allowed the identification of differential proteolytic cleavage patterns of the P97 adhesin in the three strains. For more comprehensive protein profiling, an LC-MS/MS strategy was used. Overall, 35% of the M. hyopneumoniae genome coding capacity was covered. Partially overlapping profiles of identified proteins were observed in the strains with 81 proteins identified only in one strain and 54 proteins identified in two strains. Abundance analysis of proteins detected in more than one strain demonstrates the relative overexpression of 64 proteins, including the P97 adhesin in the pathogenic strains. Conclusions Our results indicate the physiological differences between the non-pathogenic strain, with its non-infective proliferate lifestyle, and the pathogenic strains, with its constitutive expression of adhesins, which would render the bacterium competent for adhesion and infection prior to host contact.

  13. Antimicrobial susceptibility profile of Neisseria gonorrhoeae at STI clinic

    Directory of Open Access Journals (Sweden)

    Shilpee C

    2008-01-01

    Full Text Available A total of 100 consecutive patients who attended a sexually transmitted infections clinic were studied. Thirteen had gonococcal urethritis, of which 10 showed growth of Neisseria gonorrhoeae on culture. All the isolates were tested for antimicrobial susceptibility by Australian Gonococcal Surveillance Programme (AGSP method and beta lactamase production by chromogenic cephalosporin test. Four patients were co-infected with each of the following: HIV, HBV and Chlamydia trachomatis . Gonococcal urethritis (13% was found more in male patients. Ten percent gonococcal isolates were penicillinase-producing N. gonorrhoeae , and another 10% were tetracycline-resistant N. gonorrhoeae .

  14. Polymicrobial infective endocarditis caused by Neisseria sicca and Haemophilus parainfluenzae

    Directory of Open Access Journals (Sweden)

    Nikoloz Koshkelashvili

    2016-01-01

    Full Text Available Infective endocarditis is a common clinical problem in industrialized countries. Risk factors include abnormal cardiac valves, a history of endocarditis, intracardiac devices, prosthetic valves and intravenous drug use. We report a case of polymicrobial infective endocarditis in a 33 year-old female with a history chronic heroin use caused by Neisseria sicca and Haemophilus parainfluenzae. We believe the patient was exposed to these microbes by cleansing her skin with saliva prior to injection. Pairing a detailed history with the consideration of atypical agents is crucial in the proper diagnosis and management of endocarditis in patients with high-risk injection behaviors.

  15. Oligo-DNA custom macroarray for monitoring major pathogenic and non-pathogenic fungi and bacteria in the phyllosphere of apple trees.

    Directory of Open Access Journals (Sweden)

    Ying-Hong He

    Full Text Available BACKGROUND: To monitor the richness in microbial inhabitants in the phyllosphere of apple trees cultivated under various cultural and environmental conditions, we developed an oligo-DNA macroarray for major pathogenic and non-pathogenic fungi and bacteria inhabiting the phyllosphere of apple trees. METHODS AND FINDINGS: First, we isolated culturable fungi and bacteria from apple orchards by an agar-plate culture method, and detected 32 fungal and 34 bacterial species. Alternaria, Aureobasidium, Cladosporium, Rhodotorula, Cystofilobasidium, and Epicoccum genera were predominant among the fungi, and Bacillus, Pseudomonas, Sphingomonas, Methylobacterium, and Pantoea genera were predominant among the bacteria. Based on the data, we selected 29 major non-pathogenic and 12 phytopathogenic fungi and bacteria as the targets of macroarray. Forty-one species-specific 40-base pair long oligo-DNA sequences were selected from the nucleotide sequences of rDNA-internal transcribed spacer region for fungi and 16S rDNA for bacteria. The oligo-DNAs were fixed on nylon membrane and hybridized with digoxigenin-labeled cRNA probes prepared for each species. All arrays except those for Alternaria, Bacillus, and their related species, were specifically hybridized. The array was sensitive enough to detect 10(3 CFU for Aureobasidium pullulans and Bacillus cereus. Nucleotide sequencing of 100 each of independent fungal rDNA-ITS and bacterial 16S-rDNA sequences from apple tree was in agreement with the macroarray data obtained using the same sample. Finally, we analyzed the richness in the microbial inhabitants in the samples collected from apple trees in four orchards. Major apple pathogens that cause scab, Alternaria blotch, and Marssonina blotch were detected along with several non-phytopathogenic fungal and bacterial inhabitants. CONCLUSIONS: The macroarray technique presented here is a strong tool to monitor the major microbial species and the community structures in

  16. Origin of the diversity in DNA recognition domains in phasevarion associated modA genes of pathogenic Neisseria and Haemophilus influenzae.

    Science.gov (United States)

    Gawthorne, Jayde A; Beatson, Scott A; Srikhanta, Yogitha N; Fox, Kate L; Jennings, Michael P

    2012-01-01

    Phase variable restriction-modification (R-M) systems have been identified in a range of pathogenic bacteria. In some it has been demonstrated that the random switching of the mod (DNA methyltransferase) gene mediates the coordinated expression of multiple genes and constitutes a phasevarion (phase variable regulon). ModA of Neisseria and Haemophilus influenzae contain a highly variable, DNA recognition domain (DRD) that defines the target sequence that is modified by methylation and is used to define modA alleles. 18 distinct modA alleles have been identified in H. influenzae and the pathogenic Neisseria. To determine the origin of DRD variability, the 18 modA DRDs were used to search the available databases for similar sequences. Significant matches were identified between several modA alleles and mod gene from distinct bacterial species, indicating one source of the DRD variability was via horizontal gene transfer. Comparison of DRD sequences revealed significant mosaicism, indicating exchange between the Neisseria and H. influenzae modA alleles. Regions of high inter- and intra-allele similarity indicate that some modA alleles had undergone recombination more frequently than others, generating further diversity. Furthermore, the DRD from some modA alleles, such as modA12, have been transferred en bloc to replace the DRD from different modA alleles.

  17. Fastidious Gram-Negatives: Identification by the Vitek 2 Neisseria-Haemophilus Card and by Partial 16S rRNA Gene Sequencing Analysis

    DEFF Research Database (Denmark)

    Wolff Sönksen, Ute; Christensen, Jens Jørgen; Nielsen, Lisbeth

    2010-01-01

    Taxonomy and identification of fastidious Gram negatives are evolving and challenging. We compared identifications achieved with the Vitek 2 Neisseria-Haemophilus (NH) card and partial 16S rRNA gene sequence (526 bp stretch) analysis with identifications obtained with extensive phenotypic...... characterization using 100 fastidious Gram negative bacteria. Seventy-five strains represented 21 of the 26 taxa included in the Vitek 2 NH database and 25 strains represented related species not included in the database. Of the 100 strains, 31 were the type strains of the species. Vitek 2 NH identification...

  18. Ecology and Genomic Insights into Plant-Pathogenic and Plant-Nonpathogenic Endophytes.

    Science.gov (United States)

    Brader, Günter; Compant, Stéphane; Vescio, Kathryn; Mitter, Birgit; Trognitz, Friederike; Ma, Li-Jun; Sessitsch, Angela

    2017-08-04

    Plants are colonized on their surfaces and in the rhizosphere and phyllosphere by a multitude of different microorganisms and are inhabited internally by endophytes. Most endophytes act as commensals without any known effect on their plant host, but multiple bacteria and fungi establish a mutualistic relationship with plants, and some act as pathogens. The outcome of these plant-microbe interactions depends on biotic and abiotic environmental factors and on the genotype of the host and the interacting microorganism. In addition, endophytic microbiota and the manifold interactions between members, including pathogens, have a profound influence on the function of the system plant and the development of pathobiomes. In this review, we elaborate on the differences and similarities between nonpathogenic and pathogenic endophytes in terms of host plant response, colonization strategy, and genome content. We furthermore discuss environmental effects and biotic interactions within plant microbiota that influence pathogenesis and the pathobiome.

  19. Living biointerfaces based on non-pathogenic bacteria to direct cell differentiation

    Science.gov (United States)

    Rodrigo-Navarro, Aleixandre; Rico, Patricia; Saadeddin, Anas; Garcia, Andres J.; Salmeron-Sanchez, Manuel

    2014-07-01

    Genetically modified Lactococcus lactis, non-pathogenic bacteria expressing the FNIII7-10 fibronectin fragment as a protein membrane have been used to create a living biointerface between synthetic materials and mammalian cells. This FNIII7-10 fragment comprises the RGD and PHSRN sequences of fibronectin to bind α5β1 integrins and triggers signalling for cell adhesion, spreading and differentiation. We used L. lactis strain to colonize material surfaces and produce stable biofilms presenting the FNIII7-10 fragment readily available to cells. Biofilm density is easily tunable and remains stable for several days. Murine C2C12 myoblasts seeded over mature biofilms undergo bipolar alignment and form differentiated myotubes, a process triggered by the FNIII7-10 fragment. This biointerface based on living bacteria can be further modified to express any desired biochemical signal, establishing a new paradigm in biomaterial surface functionalisation for biomedical applications.

  20. Effects of nonpathogenic bacteria on cytokine secretion by human intestinal mucosa.

    Science.gov (United States)

    Borruel, Natalia; Casellas, Francesc; Antolín, María; Llopis, Marta; Carol, Monica; Espíin, Eloy; Naval, Javier; Guarner, Francisco; Malagelada, Juan R

    2003-04-01

    The human intestine harbors a complex microbial ecosystem, and the mucosa is the interface between the immune system and the luminal environment. The aim of this study was to elucidate whether host-bacteria interactions influence mucosal cytokine production. Macroscopically normal colonic specimens were obtained at surgery from eight patients with neoplasm, and inflamed ileal specimens were obtained from two patients with Crohn's disease. Mucosal explants were cultured for 24 h with either nonpathogenic Escherichia coli ECOR-26, Lactobacillus casei DN-114 001, L. casei DN-114 056, L. casei ATCC-334, or Lactobacillus bulgaricus LB-10. Each study included blank wells with no bacteria. Tissue and bacteria viability were confirmed by LDH release and culture. Concentration of tumor necrosis factor (TNF)alpha, transforming growth factor beta1, interleukin (IL)-8, and IL-10 was measured in supernatants. In parallel experiments, neutralizing anti-TNFalpha antibody was added to the culture. Co-culture of mucosa with bacteria did not modify LDH release. Co-culture with L. casei strains significantly reduced TNFalpha release, whereas E. coli increased it. These effects were observed both in normal and inflamed mucosa. In combination studies, L. casei DN-114 001 prevented TNFalpha stimulation by E. coli. L. casei DN-114 001 also reduced IL-8 release via a TNFalpha-independent pathway. L. casei DN-114 056 or E. coli increased IL-10 release in the presence of neutralizing anti-TNFalpha. Nonpathogenic bacteria interact with human intestinal mucosa and can induce changes in cytokine production that are strain specific.

  1. The Tick Microbiome: Why Non-pathogenic Microorganisms Matter in Tick Biology and Pathogen Transmission

    Directory of Open Access Journals (Sweden)

    Sarah I. Bonnet

    2017-06-01

    Full Text Available Ticks are among the most important vectors of pathogens affecting humans and other animals worldwide. They do not only carry pathogens however, as a diverse group of commensal and symbiotic microorganisms are also present in ticks. Unlike pathogens, their biology and their effect on ticks remain largely unexplored, and are in fact often neglected. Nonetheless, they can confer multiple detrimental, neutral, or beneficial effects to their tick hosts, and can play various roles in fitness, nutritional adaptation, development, reproduction, defense against environmental stress, and immunity. Non-pathogenic microorganisms may also play a role in driving transmission of tick-borne pathogens (TBP, with many potential implications for both human and animal health. In addition, the genetic proximity of some pathogens to mutualistic symbionts hosted by ticks is evident when studying phylogenies of several bacterial genera. The best examples are found within members of the Rickettsia, Francisella, and Coxiella genera: while in medical and veterinary research these bacteria are traditionally recognized as highly virulent vertebrate pathogens, it is now clear to evolutionary ecologists that many (if not most Coxiella, Francisella, and Rickettsia bacteria are actually non-pathogenic microorganisms exhibiting alternative lifestyles as mutualistic ticks symbionts. Consequently, ticks represent a compelling yet challenging system in which to study microbiomes and microbial interactions, and to investigate the composition, functional, and ecological implications of bacterial communities. Ultimately, deciphering the relationships between tick microorganisms as well as tick symbiont interactions will garner invaluable information, which may aid in the future development of arthropod pest and vector-borne pathogen transmission control strategies.

  2. Coating of silicone with mannoside-PAMAM dendrimers to enhance formation of non-pathogenic Escherichia coli biofilms against colonization of uropathogens.

    Science.gov (United States)

    Zhu, Zhiling; Yu, Fei; Chen, Haoqing; Wang, Jun; Lopez, Analette I; Chen, Quan; Li, Siheng; Long, Yuyu; Darouiche, Rabih O; Hull, Richard A; Zhang, Lijuan; Cai, Chengzhi

    2017-12-01

    Bacterial interference using non-pathogenic Escherichia coli 83972 is a novel strategy for preventing catheter-associated urinary tract infection (CAUTI). Crucial to the success of this strategy is to establish a high coverage and stable biofilm of the non-pathogenic bacteria on the catheter surface. However, this non-pathogenic strain is sluggish to form biofilms on silicone as the most widely used material for urinary catheters. We have addressed this issue by modifying the silicone catheter surfaces with mannosides that promote the biofilm formation, but the stability of the non-pathogenic biofilms challenged by uropathogens over long-term remains a concern. Herein, we report our study on the stability of the non-pathogenic biofilms grown on propynylphenyl mannoside-modified silicone. The result shows that 94% non-pathogenic bacteria were retained on the modified silicone under >0.5 Pa shear stress. After being challenged by three multidrug-resistant uropathogenic isolates in artificial urine for 11 days, large amounts (>4 × 10 6  CFU cm -2 ) of the non-pathogenic bacteria remained on the surfaces. These non-pathogenic biofilms reduced the colonization of the uropathogens by >3.2-log. In bacterial interference, the non-pathogenic Escherichia coli strains are sluggish to form biofilms on the catheter surfaces, due to rapid removal by urine flow. We have demonstrated a solution to this bottleneck by pre-functionalization of mannosides on the silicone surfaces to promote E. coli biofilm formation. A pre-conjugated high affinity propynylphenyl mannoside ligand tethered to the nanometric amino-terminated poly(amido amine) (PAMAM) dendrimer is used for binding to a major E. coli adhesin FimH. It greatly improves the efficiency for the catheter modification, the non-pathogenic biofilm coverage, as well as the (long-term) stability for prevention of uropathogen infections. Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  3. Neisseria gonorrhoeae: testing, typing and treatment in an era of increased antimicrobial resistance

    NARCIS (Netherlands)

    Wind, C.M.

    2017-01-01

    This thesis discusses the management of Neisseria gonorrhoeae infections while under threat of emerging antimicrobial resistance. It focuses on improved diagnostics, and antimicrobial resistance to current and future therapies. We describe a new method of targeted deferred culture, using nucleic

  4. Distinct Neisseria gonorrhoeae Transmission Networks Among Men Who Have Sex With Men in Amsterdam, the Netherlands

    NARCIS (Netherlands)

    Heymans, Raymond; A Matser, Amy; Bruisten, Sylvia M.; Heijman, Titia; Geskus, Ronald B.; Speksnijder, Adrianus G. C. L.; Davidovich, Udi; de Vries, Henry J. C.; Coutinho, Roel A.; Schim van der Loeff, Maarten F.

    2012-01-01

    Background. Molecular typing was used to elucidate Neisseria gonorrhoeae transmission networks among men who have sex with men (MSM) in Amsterdam, the Netherlands. We determined whether clusters of patients infected with specific N. gonorrhoeae genotypes were related to various epidemiological

  5. 21 CFR 866.3390 - Neisseria spp. direct serological test reagents.

    Science.gov (United States)

    2010-04-01

    ... SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3390... Neisseria spp. directly from clinical specimens. The identification aids in the diagnosis of disease caused...

  6. Rapid change in the ciprofloxacin resistance pattern among Neisseria gonorrhoeae strains in Nuuk, Greenland

    DEFF Research Database (Denmark)

    Skjerbæk Rolskov, Anne; Bjorn-Mortensen, Karen; Mulvad, Gert

    2015-01-01

    OBJECTIVES: Sexually transmitted infections (STIs), including infections with Neisseria gonorrhoeae (GC), are highly incident in Greenland. Since January 2011, GC testing has been performed on urine with nucleic acid amplification tests (NAATs) by strand displacement amplification (Becton Dickins...

  7. Meropenem susceptibility of Neisseria meningitidis and Streptococcus pneumoniae from meningitis patients in The Netherlands

    NARCIS (Netherlands)

    van de Beek, D.; Hensen, E. F.; Spanjaard, L.; de Gans, J.; Enting, R. H.; Dankert, J.

    1997-01-01

    In-vitro susceptibility of 299 Neisseria meningitidis and 157 Streptococcus pneumoniae strains from meningitis patients in The Netherlands in 1993 and 1994 to meropenem was determined using the Etest. Susceptibility to penicillin, ceftriaxone, and chloramphenicol was also determined. Rifampicin

  8. Design of a multiplex PCR assay for the simultaneous detection and confirmation of Neisseria gonorrhoeae.

    LENUS (Irish Health Repository)

    O'Callaghan, Isabelle

    2010-05-01

    To improve the detection of Neisseria gonorrhoeae by designing a multiplex PCR assay using two N gonorrhoeae-specific genes as targets, thereby providing detection and confirmation of a positive result simultaneously.

  9. Antimicrobial susceptibility pattern of Neisseria gonorrhoeae in western Austria.

    Science.gov (United States)

    Allerberger, F; Kofler, H; Brezinka, C; Guggenbichler, J P; Dierich, M P

    1993-01-01

    From January to October 1992 24 Neisseria gonorrhoeae isolates from clinical specimens were collected at the Federal Public Health Laboratory in Innsbruck (Austria) and screened for resistance to penicillin G, erythromycin, tetracycline, spectinomycin, ceftriaxone, cefuroxime, ciprofloxacine, and silver nitrate. Patients originated from the Austrian provinces Salzburg, Tirol, and Vorarlberg, and presented with manifest gonorrhoea. Two of 24 isolates were penicillinase-producing N. gonorrhoeae. Both strains were isolated from men who had just returned from Thailand or Kenya. The isolate from Africa was also resistant to tetracycline. Five of 24 infections were acquired abroad, sex tourism being involved in four cases. The antimicrobial resistance pattern found in gonococci in western Austria revealed that topical silver nitrate and erythromycin are equally acceptable for use in prophylaxis of neonatal ophthalmia. Penicillin is still the drug of choice in the treatment of endemic infections. If gonorrhoea has been acquired abroad, especially in Asia or Africa, ceftriaxone, spectinomycin or ciprofloxazine are recommended for therapy.

  10. Neisseria meningitidis presenting as acute abdomen and recurrent reactive pericarditis

    Directory of Open Access Journals (Sweden)

    Karolina Akinosoglou

    2016-11-01

    Full Text Available Meningococcal meningitis is a well established potential fatal infection characterized by fever, headache, petechial rash, and vomiting in the majority of cases. However, protean manifestations including abdominal pain, sore throat, diarrhea and cough, even though rare, should not be overlooked. Similarly, although disseminated infection could potentially involve various organ-targets, secondary immune related complications including joints or pericardium should be dealt with caution, since they remain unresponsive to appropriate antibiotic regimens. We hereby report the rare case of an otherwise healthy adult female, presenting with acute abdominal pain masking Neisseria meningitidis serotype B meningitis, later complicated with recurrent reactive pericarditis despite appropriate antibiotic treatment. There follows a review of current literature.

  11. Large Cluster of Neisseria meningitidis Urethritis in Columbus, Ohio, 2015.

    Science.gov (United States)

    Bazan, Jose A; Turner, Abigail Norris; Kirkcaldy, Robert D; Retchless, Adam C; Kretz, Cecilia B; Briere, Elizabeth; Tzeng, Yih-Ling; Stephens, David S; Maierhofer, Courtney; Del Rio, Carlos; Abrams, A Jeanine; Trees, David L; Ervin, Melissa; Licon, Denisse B; Fields, Karen S; Roberts, Mysheika Williams; Dennison, Amanda; Wang, Xin

    2017-07-01

    Neisseria meningitidis (Nm) is a Gram-negative diplococcus that normally colonizes the nasopharynx and rarely infects the urogenital tract. On Gram stain of urethral exudates, Nm can be misidentified as the more common sexually transmitted pathogen Neisseria gonorrhoeae. In response to a large increase in cases of Nm urethritis identified among men presenting for screening at a sexually transmitted disease clinic in Columbus, Ohio, we investigated the epidemiologic characteristics of men with Nm urethritis and the molecular and phylogenetic characteristics of their Nm isolates. The study was conducted between 1 January and 18 November 2015. Seventy-five Nm urethritis cases were confirmed by biochemical and polymerase chain reaction testing. Men with Nm urethritis were a median age of 31 years (interquartile range [IQR] = 24-38) and had a median of 2 sex partners in the last 3 months (IQR = 1-3). Nm cases were predominantly black (81%) and heterosexual (99%). Most had urethral discharge (91%), reported oral sex with a female in the last 12 months (96%), and were treated with a ceftriaxone-based regimen (95%). A minority (15%) also had urethral chlamydia coinfection. All urethral Nm isolates were nongroupable, ST-11 clonal complex (cc11), ET-15, and clustered together phylogenetically. Urethral Nm isolates were similar by fine typing (PorA P1.5-1,10-8, PorB 2-2, FetA F3-6), except 2, which had different PorB types (2-78 and 2-52). Between January and November 2015, 75 urethritis cases due to a distinct Nm clade occurred among primarily black, heterosexual men in Columbus, Ohio. Future urogenital Nm infection studies should focus on pathogenesis and modes of sexual transmission. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.

  12. Antimicrobial effect of probiotics on bacterial species from dental plaque.

    Science.gov (United States)

    Zambori, Csilla; Morvay, Attila Alexandru; Sala, Claudia; Licker, Monica; Gurban, Camelia; Tanasie, Gabriela; Tirziu, Emil

    2016-03-31

    The antimicrobial role of probiotic Lactobacillus casei subspecies casei DG (L. casei DG) and of the mix culture of probiotic Lactobacillus acidophilus LA-5 and Bifidobacterium BB-12 was tested on species of Staphylococcus, Streptococcus, Pasteurella, and Neisseria genera from supragingival sites from dogs with dental disease of different breed, age, sex, weight, and diet. The research was conducted on these four genera because of their importance in zoonotic infections after dog bites. Species from Staphylococcus, Streptococcus, Pasteurella, and Neisseria genera were isolated and identified. To test the antimicrobial efficacy of L. casei DG and the mixed culture of probiotic L. acidophilus LA-5 and Bifidobacterium bifidum BB-12 on the pathogenic species, the agar overlay method was used. L. casei DG had a bactericidal effect on all analyzed species isolated from Staphylococcus, Streptococcus, Pasteurella, and Neisseria genera after 24 hours of incubation. The mixed probiotic culture made up of L. acidophilus LA-5 and Bifidobacterium BB-12 species had no bactericidal effect on the species of Staphylococcus and Streptococcus genera, which were resistant. However, it had a bacteriostatic effect on several species of Pasteurella and Neisseria genera. This work highlights the antimicrobial potential of probiotics in vitro, demonstrating that the probiotic L. casei DG has a bactericidal effect on all analyzed species isolated from dental plaque and that the mix culture of probiotic L. acidophilus LA-5 and Bifidobacterium BB-12 has only a bacteriostatic effect.

  13. Cloning, nucleotide sequence and transcriptional analysis of the uvrA gene from Neisseria gonorrhoeae

    International Nuclear Information System (INIS)

    Black, C.G.; Fyfe, J.A.M.; Davies, J.K.

    1997-01-01

    A recombinant plasmid capable of restoring UV resistance to an Escherichia coli uvrA mutant was isolated from a genomic library of Neisseria gonorrhoeae. Sequence analysis revealed an open reading frame whose deduced amino acid sequence displayed significant similarity to those of the UvrA proteins of other bacterial species. A second open reading frame (ORF259) was identified upstream from, and in the opposite orientation to the gonococcal uvrA gene. Transcriptional fusions between portions of the gonococcal uvrA upstream region and a reporter gene were used to localise promoter activity in both E. coli and N. gonorrhoeae. The transcriptional starting points of uvrA and ORF259 were mapped in E. coli by primer extension analysis, and corresponding σ 70 promoters were identified. The arrangement of the uvrA-ORF259 intergenic region is similar to that of the gonococcal recA-aroD intergenic region. Both contain inverted copies of the 10 bp neisserial DNA uptake sequence situated between divergently transcribed genes. However, there is no evidence that either the uptake sequence or the proximity of the promoters influences expression of these genes. (author)

  14. Biochemical analysis of plant protection afforded by a nonpathogenic endophytic mutant of Colletotrichum magna

    Energy Technology Data Exchange (ETDEWEB)

    Redman, R.S.; Rodriguez, R.J. (Geological Survey, Seattle, WA (United States) Univ. of Washington, Seattle, WA (United States). Dept. of Botany); Clifton, D.R.; Morrel, J.; Brown, G. (Geological Survey, Seattle, WA (United States)); Freeman, S. (Volcani Center, Bet Dagan (Israel). Dept. of Plant Pathology)

    1999-02-01

    A nonpathogenic mutant of Colletotrichum magna (path-1) was previously shown to protect watermelon (Citrullus lanatus) and cucumber (Cucumis sativus) seedlings from anthracnose disease elicited by wild-type C. magna. Disease protection was observed in stems of path-1-colonized cucurbits but not in cotyledons, indicating that path-1 conferred tissue-specific and/or localized protection. Plant biochemical indicators of a localized and systemic (peroxidase, phenylalanine ammonia-lyase, lignin, and salicylic acid) plant-defense response were investigated in anthracnose-resistant and-susceptible cultivars of cucurbit seedlings exposed to four treatments: (1) water (control), (2) path-1 conidia, (3) wild-type conidia, and (4) challenge conditions (inoculation into path-1 conidia for 48 h and then exposure to wild-type conidia). Collectively, these analyses indicated that disease protection in path-1-colonized plants was correlated with the ability of these plants to mount a defense response more rapidly and to equal or greater levels than plants exposed to wild-type C. magna alone. Watermelon plants colonized with path-1 were also protected against disease caused by Colletotrichum orbiculare and Fusarium oxysporum. A model based on the kinetics of plant-defense activation is presented to explain the mechanism of path-1-conferred disease protection.

  15. A nonpathogenic Fusarium oxysporum strain enhances phytoextraction of heavy metals by the hyperaccumulator Sedum alfredii Hance.

    Science.gov (United States)

    Zhang, Xincheng; Lin, Li; Chen, Mingyue; Zhu, Zhiqiang; Yang, Weidong; Chen, Bao; Yang, Xiaoe; An, Qianli

    2012-08-30

    Low biomass and shallow root systems limit the application of heavy metal phytoextraction by hyperaccumulators. Plant growth-promoting microbes may enhance hyperaccumulators'phytoextraction. A heavy metal-resistant fungus belonged to the Fusarium oxysporum complex was isolated from the Zn/Cd co-hyperaccumulator Sedum alfredii Hance grown in a Pb/Zn mined area. This Fusarium fungus was not pathogenic to plants but promoted host growth. Hydroponic experiments showed that 500 μM Zn(2+) or 50 μM Cd(2+) combined with the fungus increased root length, branches, and surface areas, enhanced nutrient uptake and chlorophyll synthesis, leading to more vigorous hyperaccumulators with greater root systems. Soil experiments showed that the fungus increased root and shoot biomass and S. alfredii-mediated heavy metal availabilities, uptake, translocation or concentrations, and thus increased phytoextraction of Zn (144% and 44%), Cd (139% and 55%), Pb (84% and 85%) and Cu (63% and 77%) from the original Pb/Zn mined soil and a multi-metal contaminated paddy soil. Together, the nonpathogenic Fusarium fungus was able to increase S. alfredii root systems and function, metal availability and accumulation, plant biomass, and thus phytoextraction efficiency. This study showed a great application potential for culturable indigenous fungi other than symbiotic mycorrhizas to enhance the phytoextraction by hyperaccumulators. Copyright © 2012 Elsevier B.V. All rights reserved.

  16. Living biointerfaces based on non-pathogenic bacteria support stem cell differentiation

    Science.gov (United States)

    Hay, Jake J.; Rodrigo-Navarro, Aleixandre; Hassi, Karoliina; Moulisova, Vladimira; Dalby, Matthew J.; Salmeron-Sanchez, Manuel

    2016-02-01

    Lactococcus lactis, a non-pathogenic bacteria, has been genetically engineered to express the III7-10 fragment of human fibronectin as a membrane protein. The engineered L. lactis is able to develop biofilms on different surfaces (such as glass and synthetic polymers) and serves as a long-term substrate for mammalian cell culture, specifically human mesenchymal stem cells (hMSC). This system constitutes a living interface between biomaterials and stem cells. The engineered biofilms remain stable and viable for up to 28 days while the expressed fibronectin fragment induces hMSC adhesion. We have optimised conditions to allow long-term mammalian cell culture, and found that the biofilm is functionally equivalent to a fibronectin-coated surface in terms of osteoblastic differentiation using bone morphogenetic protein 2 (BMP-2) added to the medium. This living bacteria interface holds promise as a dynamic substrate for stem cell differentiation that can be further engineered to express other biochemical cues to control hMSC differentiation.

  17. Phasevarions mediate random switching of gene expression in pathogenic Neisseria.

    Directory of Open Access Journals (Sweden)

    Yogitha N Srikhanta

    2009-04-01

    Full Text Available Many host-adapted bacterial pathogens contain DNA methyltransferases (mod genes that are subject to phase-variable expression (high-frequency reversible ON/OFF switching of gene expression. In Haemophilus influenzae, the random switching of the modA gene controls expression of a phase-variable regulon of genes (a "phasevarion", via differential methylation of the genome in the modA ON and OFF states. Phase-variable mod genes are also present in Neisseria meningitidis and Neisseria gonorrhoeae, suggesting that phasevarions may occur in these important human pathogens. Phylogenetic studies on phase-variable mod genes associated with type III restriction modification (R-M systems revealed that these organisms have two distinct mod genes--modA and modB. There are also distinct alleles of modA (abundant: modA11, 12, 13; minor: modA4, 15, 18 and modB (modB1, 2. These alleles differ only in their DNA recognition domain. ModA11 was only found in N. meningitidis and modA13 only in N. gonorrhoeae. The recognition site for the modA13 methyltransferase in N. gonorrhoeae strain FA1090 was identified as 5'-AGAAA-3'. Mutant strains lacking the modA11, 12 or 13 genes were made in N. meningitidis and N. gonorrhoeae and their phenotype analyzed in comparison to a corresponding mod ON wild-type strain. Microarray analysis revealed that in all three modA alleles multiple genes were either upregulated or downregulated, some of which were virulence-associated. For example, in N. meningitidis MC58 (modA11, differentially expressed genes included those encoding the candidate vaccine antigens lactoferrin binding proteins A and B. Functional studies using N. gonorrhoeae FA1090 and the clinical isolate O1G1370 confirmed that modA13 ON and OFF strains have distinct phenotypes in antimicrobial resistance, in a primary human cervical epithelial cell model of infection, and in biofilm formation. This study, in conjunction with our previous work in H. influenzae, indicates

  18. Phasevarions mediate random switching of gene expression in pathogenic Neisseria.

    Science.gov (United States)

    Srikhanta, Yogitha N; Dowideit, Stefanie J; Edwards, Jennifer L; Falsetta, Megan L; Wu, Hsing-Ju; Harrison, Odile B; Fox, Kate L; Seib, Kate L; Maguire, Tina L; Wang, Andrew H-J; Maiden, Martin C; Grimmond, Sean M; Apicella, Michael A; Jennings, Michael P

    2009-04-01

    Many host-adapted bacterial pathogens contain DNA methyltransferases (mod genes) that are subject to phase-variable expression (high-frequency reversible ON/OFF switching of gene expression). In Haemophilus influenzae, the random switching of the modA gene controls expression of a phase-variable regulon of genes (a "phasevarion"), via differential methylation of the genome in the modA ON and OFF states. Phase-variable mod genes are also present in Neisseria meningitidis and Neisseria gonorrhoeae, suggesting that phasevarions may occur in these important human pathogens. Phylogenetic studies on phase-variable mod genes associated with type III restriction modification (R-M) systems revealed that these organisms have two distinct mod genes--modA and modB. There are also distinct alleles of modA (abundant: modA11, 12, 13; minor: modA4, 15, 18) and modB (modB1, 2). These alleles differ only in their DNA recognition domain. ModA11 was only found in N. meningitidis and modA13 only in N. gonorrhoeae. The recognition site for the modA13 methyltransferase in N. gonorrhoeae strain FA1090 was identified as 5'-AGAAA-3'. Mutant strains lacking the modA11, 12 or 13 genes were made in N. meningitidis and N. gonorrhoeae and their phenotype analyzed in comparison to a corresponding mod ON wild-type strain. Microarray analysis revealed that in all three modA alleles multiple genes were either upregulated or downregulated, some of which were virulence-associated. For example, in N. meningitidis MC58 (modA11), differentially expressed genes included those encoding the candidate vaccine antigens lactoferrin binding proteins A and B. Functional studies using N. gonorrhoeae FA1090 and the clinical isolate O1G1370 confirmed that modA13 ON and OFF strains have distinct phenotypes in antimicrobial resistance, in a primary human cervical epithelial cell model of infection, and in biofilm formation. This study, in conjunction with our previous work in H. influenzae, indicates that

  19. [Neisseria meningitidis urethritis: Two case reports].

    Science.gov (United States)

    Dubois, C; Liegeon, A-L; Fabbro, C; Truchetet, F

    2017-10-01

    Neisseria meningitidis (NM) is a commensal bacteria present in the oropharyngeal flora that causes invasive infections. There have been rarer reports of presence in the genital region. Herein, we present two cases of acute NM urethritis. Two men aged 30 and 31years, one of whom is homosexual and seropositive for HIV infection, presented urethral discharge which was diagnosed as acute urethritis. The unit through samples indicated the presence of NM of serogroups B and C. One of the antibiotic sensitivity tests revealed intermediate susceptibility to penicillin G and to amoxicillin. The clinical presentation of acute NM urethritis is non-specific, because of which urethral samples should be taken wherever acute urethritis is suspected. NM urethritis is infrequent and primarily affects men who have sex with men (MSM). Its current increase is due to unprotected oral-genital sexual practices. Due to the emergence of resistance to NM, antibiotic susceptibility testing should be carried out routinely to ensure appropriate therapy and prophylaxis. Cases of invasive serogroup C meningococcal infections have been recorded within the MSM population with hypothetical sexual port of entry. Thus, the French High Public Health Authority recommends vaccination against meningitis C in this population. Copyright © 2017. Published by Elsevier Masson SAS.

  20. Antimicrobial drug susceptibility of Neisseria meningitidis strains isolated from carriers

    Directory of Open Access Journals (Sweden)

    Dayamí García

    2000-06-01

    Full Text Available When it is necessary to determine the susceptibility of Neisseria meningitidis (Nm strains to antimicrobial drugs, it is important to consider that it should be analyzed in a double context. One of them related to the use of drugs in a specific medical treatment; and the other; to chemoprophylatic drugs, both with the same purpose: the accurate selection of the “in vivo” antimicrobial agent. This requires the study of the sensitivity and resistance of strains isolated in both carriers and patients. With the aim of further studying the behavior of the strains that currently circulate in Cuba, an antimicrobial drug susceptibility study was conducted in 90 strains isolated from carriers during the first half of 1998. The agar dilution method was used to determine the minimum inhibitory concentrations (MICs to: penicillin, ampicillin, rifampin, sulfadiazine, chloramphenicol, ciprofloxacin, ceftriaxone, cefotaxime. The study of the three latter drugs was done for the first time in our country. The search for β- lactamase-producer strains was also performed. There was a predominance of penicillin sensitive strains (82,2% with an intermediate sensitivity to ampicillin (57,8%, while 70% of the strains were sensitive to sulfadiazine. Regarding the rest of the antimicrobial drugs, 100% of the strains were sensitive. The paper shows the MICs for each drug as well as the phenotypic characteristics of the strains with the penicillin and sulfadiazine sensitivity and resistance patterns. No β-lactamase-producer strains were found.

  1. Agar dilution method for susceptibility testing of Neisseria gonorrhoeae

    Directory of Open Access Journals (Sweden)

    Marta C de Castillo

    1996-12-01

    Full Text Available The antibiotic susceptibilities of Neisseria gonorrhoeae isolates obtained from patients attending a clinic for sexually transmitted diseases in Tucumán, Argentina, were determined by the agar dilution method (MIC. 3.5% of the isolates produced ²-lactamase. A total of 96.5% of ²-lactamase negative isolates tested were susceptible to penicillin (MIC < 2 µgml-1; 14.03% of the tested isolates were resistant to tetracycline (MIC < 2 µgml-1, and 98% of the tested isolates were susceptible to spectinomycin (MIC < 64 µgml-1. The MICs for 95% of the isolates, tested for other drugs were: < 2 µgml-1 for cefoxitin, < 0.06 µgml-1 for cefotaxime, < 0.25 µgml-1 for norfloxacin, < 10 µgml-1 for cephaloridine, < 10 µgml-1 for cephalexin, and < 50 µgml-1 for kanamycin. Antibiotic resistance among N. gonorrhoeae isolates from Tucumán, Argentina, appeared to be primarily limited to penicillin and tetracycline, which has been a general use against gonorrhoeae in Tucumán since 1960. Periodic monitoring of the underlying susceptibility profiles of the N. gonorrhoeae strains prevalent in areas of frequent transmission may provide clues regarding treatment options and emerging of drug resistance.

  2. Biological Functions of the Secretome of Neisseria meningitidis

    Directory of Open Access Journals (Sweden)

    Jan Tommassen

    2017-06-01

    Full Text Available Neisseria meningitidis is a Gram-negative bacterial pathogen that normally resides as a commensal in the human nasopharynx but occasionally causes disease with high mortality and morbidity. To interact with its environment, it transports many proteins across the outer membrane to the bacterial cell surface and into the extracellular medium for which it deploys the common and well-characterized autotransporter, two-partner and type I secretion mechanisms, as well as a recently discovered pathway for the surface exposure of lipoproteins. The surface-exposed and secreted proteins serve roles in host-pathogen interactions, including adhesion to host cells and extracellular matrix proteins, evasion of nutritional immunity imposed by iron-binding proteins of the host, prevention of complement activation, neutralization of antimicrobial peptides, degradation of immunoglobulins, and permeabilization of epithelial layers. Furthermore, they have roles in interbacterial interactions, including the formation and dispersal of biofilms and the suppression of the growth of bacteria competing for the same niche. Here, we will review the protein secretion systems of N. meningitidis and focus on the functions of the secreted proteins.

  3. [A case of bacterial peritonitis caused by Neisseria gonorrhoeae].

    Science.gov (United States)

    Akahane, T; Kawakami, Y; Oana, K

    2001-10-01

    On January 17, 2001, a 39-year old female with sudden abdominal pain was admitted to her neighboring outpatient clinic and diagnosed as suspicious of infectious enteritis. However, on the next day (January 18, 2001) she was soon transferred to Toyoshina Red Cross Hospital with the chief complaint of severe abdominal pain, high fever, and of conspicuous leucocytosis. Laboratory data on her admission demonstrated apparent signs of inflammation and she was soon undergone an emergency operation. Neisseria gonorrhoeae was recovered from her ascetic fluid, otherwise Chlamydia EIA was negative. The antibiotic chemotherapy of minocycline (200 mg/day) was continued for the first 9 days and sulbactam/cefoperazone (2 g/day) had been administered for the first 5 days. Her symptoms were discontinued on her 10th hospital day, and she was discharged on the 14th hospital day. There have been few reported cases in Japan of bacterial peritonitis due to N. gonorrhoeae. This is, to the best of our knowledge, the first reported case of N. gonorrhoeae peritonitis in Japan.

  4. Functional analysis of the Gonococcal Genetic Island of Neisseria gonorrhoeae.

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    Emilia Pachulec

    Full Text Available Neisseria gonorrhoeae is an obligate human pathogen that is responsible for the sexually-transmitted disease gonorrhea. N. gonorrhoeae encodes a T4SS within the Gonococcal Genetic Island (GGI, which secretes ssDNA directly into the external milieu. Type IV secretion systems (T4SSs play a role in horizontal gene transfer and delivery of effector molecules into target cells. We demonstrate that GGI-like T4SSs are present in other β-proteobacteria, as well as in α- and γ-proteobacteria. Sequence comparison of GGI-like T4SSs reveals that the GGI-like T4SSs form a highly conserved unit that can be found located both on chromosomes and on plasmids. To better understand the mechanism of DNA secretion by N. gonorrhoeae, we performed mutagenesis of all genes encoded within the GGI, and studied the effects of these mutations on DNA secretion. We show that genes required for DNA secretion are encoded within the yaa-atlA and parA-parB regions, while genes encoded in the yfeB-exp1 region could be deleted without any effect on DNA secretion. Genes essential for DNA secretion are encoded within at least four different operons.

  5. Epidemiological markers in Neisseria meningitidis: an estimate of the performance of genotyping vs phenotyping

    DEFF Research Database (Denmark)

    Weis, N; Lind, I

    1998-01-01

    In order to estimate the performance of genotypic vs phenotypic characterization of Neisseria meningitidis, 2 methods, DNA fingerprinting and multilocus enzyme electrophoresis (MEE), were assessed as regards applicability, reproducibility and discriminating capacity. 50 serogroup B and 52 serogro......, and as applied in the study MEE was superior to DNA fingerprinting. Clusters of invasive strains were reliably identified by phenotyping alone, whereas determination of identity of carrier strains and an invasive strain required genotyping.......In order to estimate the performance of genotypic vs phenotypic characterization of Neisseria meningitidis, 2 methods, DNA fingerprinting and multilocus enzyme electrophoresis (MEE), were assessed as regards applicability, reproducibility and discriminating capacity. 50 serogroup B and 52 serogroup...... C Neisseria meningitidis strains from 96 patients with meningococcal disease and 22 serogroup C strains from healthy carriers were investigated. Both methods were 100% applicable to meningococcal strains and results of DNA fingerprinting as well as of MEE were reproducible. The number of types...

  6. Fournier’s Gangrene in a Heterosexual Man: A Complication of Neisseria meningitidis Urethritis

    Directory of Open Access Journals (Sweden)

    Tariq A. Khemees

    2012-01-01

    Full Text Available A 55-year-old heterosexual male presented to the emergency department with a symptomatology consistent with urethritis and Fournier’s gangrene. Urethral swab and operative tissue cultures were positive for coagulase-negative Staphylococcus and an intracellular Gram-negative diplococcus. The latter was initially thought to be Neisseria gonorrhea; however, DNA sequencing technique confirmed it to be Neisseria meningitidis. The patient required three separate surgical debridements to control widespread necrotizing infection. Following documentation of sterile wound healing with appropriate antibiotics, four reconstructive surgeries were necessary to manage the resultant wound defects. To our knowledge, Neisseria meningitidis as a causative organism in Fournier’s gangrene has not been reported in the literature.

  7. Fastidious Gram-Negatives: Identification by the Vitek 2 Neisseria-Haemophilus Card and by Partial 16S rRNA Gene Sequencing Analysis

    DEFF Research Database (Denmark)

    Wolff Sönksen, Ute; Christensen, Jens Jørgen; Nielsen, Lisbeth

    2010-01-01

    Taxonomy and identification of fastidious Gram negatives are evolving and challenging. We compared identifications achieved with the Vitek 2 Neisseria-Haemophilus (NH) card and partial 16S rRNA gene sequence (526 bp stretch) analysis with identifications obtained with extensive phenotypic...... characterization using 100 fastidious Gram negative bacteria. Seventy-five strains represented 21 of the 26 taxa included in the Vitek 2 NH database and 25 strains represented related species not included in the database. Of the 100 strains, 31 were the type strains of the species. Vitek 2 NH identification...... results: 48 of 75 database strains were correctly identified, 11 strains gave `low discrimination´, seven strains were unidentified, and nine strains were misidentified. Identification of 25 non-database strains resulted in 14 strains incorrectly identified as belonging to species in the database. Partial...

  8. Resistance to β-Lactams in Neisseria ssp Due to Chromosomally Encoded Penicillin-Binding Proteins.

    Science.gov (United States)

    Zapun, André; Morlot, Cécile; Taha, Muhamed-Kheir

    2016-09-28

    Neisseria meningitidis and Neisseria gonorrhoeae are human pathogens that cause a variety of life-threatening systemic and local infections, such as meningitis or gonorrhoea. The treatment of such infection is becoming more difficult due to antibiotic resistance. The focus of this review is on the mechanism of reduced susceptibility to penicillin and other β-lactams due to the modification of chromosomally encoded penicillin-binding proteins (PBP), in particular PBP2 encoded by the penA gene. The variety of penA alleles and resulting variant PBP2 enzymes is described and the important amino acid substitutions are presented and discussed in a structural context.

  9. Overexpression of Differentially Expressed Genes Identified in Non-pathogenic and Pathogenic Entamoeba histolytica Clones Allow Identification of New Pathogenicity Factors Involved in Amoebic Liver Abscess Formation.

    Directory of Open Access Journals (Sweden)

    Martin Meyer

    2016-08-01

    Full Text Available We here compared pathogenic (p and non-pathogenic (np isolates of Entamoeba histolytica to identify molecules involved in the ability of this parasite to induce amoebic liver abscess (ALA-like lesions in two rodent models for the disease. We performed a comprehensive analysis of 12 clones (A1-A12 derived from a non-pathogenic isolate HM-1:IMSS-A and 12 clones (B1-B12 derived from a pathogenic isolate HM-1:IMSS-B. "Non-pathogenicity" included the induction of small and quickly resolved lesions while "pathogenicity" comprised larger abscess development that overstayed day 7 post infection. All A-clones were designated as non-pathogenic, whereas 4 out of 12 B-clones lost their ability to induce ALAs in gerbils. No correlation between ALA formation and cysteine peptidase (CP activity, haemolytic activity, erythrophagocytosis, motility or cytopathic activity was found. To identify the molecular framework underlying different pathogenic phenotypes, three clones were selected for in-depth transcriptome analyses. Comparison of a non-pathogenic clone A1np with pathogenic clone B2p revealed 76 differentially expressed genes, whereas comparison of a non-pathogenic clone B8np with B2p revealed only 19 differentially expressed genes. Only six genes were found to be similarly regulated in the two non-pathogenic clones A1np and B8np in comparison with the pathogenic clone B2p. Based on these analyses, we chose 20 candidate genes and evaluated their roles in ALA formation using the respective gene-overexpressing transfectants. We conclude that different mechanisms lead to loss of pathogenicity. In total, we identified eight proteins, comprising a metallopeptidase, C2 domain proteins, alcohol dehydrogenases and hypothetical proteins, that affect the pathogenicity of E. histolytica.

  10. Overexpression of Differentially Expressed Genes Identified in Non-pathogenic and Pathogenic Entamoeba histolytica Clones Allow Identification of New Pathogenicity Factors Involved in Amoebic Liver Abscess Formation.

    Science.gov (United States)

    Meyer, Martin; Fehling, Helena; Matthiesen, Jenny; Lorenzen, Stephan; Schuldt, Kathrin; Bernin, Hannah; Zaruba, Mareen; Lender, Corinna; Ernst, Thomas; Ittrich, Harald; Roeder, Thomas; Tannich, Egbert; Lotter, Hannelore; Bruchhaus, Iris

    2016-08-01

    We here compared pathogenic (p) and non-pathogenic (np) isolates of Entamoeba histolytica to identify molecules involved in the ability of this parasite to induce amoebic liver abscess (ALA)-like lesions in two rodent models for the disease. We performed a comprehensive analysis of 12 clones (A1-A12) derived from a non-pathogenic isolate HM-1:IMSS-A and 12 clones (B1-B12) derived from a pathogenic isolate HM-1:IMSS-B. "Non-pathogenicity" included the induction of small and quickly resolved lesions while "pathogenicity" comprised larger abscess development that overstayed day 7 post infection. All A-clones were designated as non-pathogenic, whereas 4 out of 12 B-clones lost their ability to induce ALAs in gerbils. No correlation between ALA formation and cysteine peptidase (CP) activity, haemolytic activity, erythrophagocytosis, motility or cytopathic activity was found. To identify the molecular framework underlying different pathogenic phenotypes, three clones were selected for in-depth transcriptome analyses. Comparison of a non-pathogenic clone A1np with pathogenic clone B2p revealed 76 differentially expressed genes, whereas comparison of a non-pathogenic clone B8np with B2p revealed only 19 differentially expressed genes. Only six genes were found to be similarly regulated in the two non-pathogenic clones A1np and B8np in comparison with the pathogenic clone B2p. Based on these analyses, we chose 20 candidate genes and evaluated their roles in ALA formation using the respective gene-overexpressing transfectants. We conclude that different mechanisms lead to loss of pathogenicity. In total, we identified eight proteins, comprising a metallopeptidase, C2 domain proteins, alcohol dehydrogenases and hypothetical proteins, that affect the pathogenicity of E. histolytica.

  11. A new zearalenone biodegradation strategy using non-pathogenic Rhodococcus pyridinivorans K408 strain.

    Science.gov (United States)

    Kriszt, Rókus; Krifaton, Csilla; Szoboszlay, Sándor; Cserháti, Mátyás; Kriszt, Balázs; Kukolya, József; Czéh, Arpád; Fehér-Tóth, Szilvia; Török, Lívia; Szőke, Zsuzsanna; Kovács, Krisztina J; Barna, Teréz; Ferenczi, Szilamér

    2012-01-01

    Zearalenone (hereafter referred to as ZEA) is a nonsteroidal estrogenic mycotoxin produced by several Fusarium spp. on cereal grains. ZEA is one of the most hazardous natural endocrine disrupting chemicals (EDC) which induces hyper estrogenic responses in mammals. This can result in reproductive disorders in farm animals as well as in humans. Consequently, detoxification strategies for contaminated crops are crucial for food safety. In this study we have developed a bacterial based detoxification system using a non-pathogen Rhodococcus pyridinivorans K408 strain. Following 5 days treatment of ZEA with R. pyridinivorans K408 strain HPLC analyses showed an 87.21% ZEA-degradation efficiency of the bacterial enzyme systems. In another approach, the strain biotransformation ability has also been confirmed by a bioluminescent version of the yeast estrogen screening system (BLYES), which detected an 81.75% of biodegradability of ZEA, in a good agreement with the chemical analyses. Furthermore, the capacity of R. pyridinivorans to eliminate the estrogenic effects of ZEA was tested by using an immature uterotrophic assay. Prepubertal female rats were treated with vehicle (olive oil), 17β-estradiol, ZEA (0.1-1-5-10 mg/kg body weight) and LB broth containing 500 mg/l ZEA that has already been incubated with or without Rhodococcus pyridinivorans K408 strain. Uterine weights were measured and the mRNA level changes relating to apelin, aquaporin 5, complement component 2, and calbindin-3 genes were measured by qRT-PCR. These genes represent the major pathways that are affected by estromimetic compounds. Zearalenone feeding significantly increased the uterus weight in a dose dependent manner and at the same time upregulated complement component 2 and calbindin-3 expression as well as decreased apelin and aquaporin 5 mRNA levels comparable to that seen in 17β-estradiol exposed rats. In contrast, LB broth in which ZEA was incubated with Rhodococcus pyridinivorans K408 prior to

  12. A new zearalenone biodegradation strategy using non-pathogenic Rhodococcus pyridinivorans K408 strain.

    Directory of Open Access Journals (Sweden)

    Rókus Kriszt

    Full Text Available Zearalenone (hereafter referred to as ZEA is a nonsteroidal estrogenic mycotoxin produced by several Fusarium spp. on cereal grains. ZEA is one of the most hazardous natural endocrine disrupting chemicals (EDC which induces hyper estrogenic responses in mammals. This can result in reproductive disorders in farm animals as well as in humans. Consequently, detoxification strategies for contaminated crops are crucial for food safety. In this study we have developed a bacterial based detoxification system using a non-pathogen Rhodococcus pyridinivorans K408 strain. Following 5 days treatment of ZEA with R. pyridinivorans K408 strain HPLC analyses showed an 87.21% ZEA-degradation efficiency of the bacterial enzyme systems. In another approach, the strain biotransformation ability has also been confirmed by a bioluminescent version of the yeast estrogen screening system (BLYES, which detected an 81.75% of biodegradability of ZEA, in a good agreement with the chemical analyses. Furthermore, the capacity of R. pyridinivorans to eliminate the estrogenic effects of ZEA was tested by using an immature uterotrophic assay. Prepubertal female rats were treated with vehicle (olive oil, 17β-estradiol, ZEA (0.1-1-5-10 mg/kg body weight and LB broth containing 500 mg/l ZEA that has already been incubated with or without Rhodococcus pyridinivorans K408 strain. Uterine weights were measured and the mRNA level changes relating to apelin, aquaporin 5, complement component 2, and calbindin-3 genes were measured by qRT-PCR. These genes represent the major pathways that are affected by estromimetic compounds. Zearalenone feeding significantly increased the uterus weight in a dose dependent manner and at the same time upregulated complement component 2 and calbindin-3 expression as well as decreased apelin and aquaporin 5 mRNA levels comparable to that seen in 17β-estradiol exposed rats. In contrast, LB broth in which ZEA was incubated with Rhodococcus pyridinivorans K

  13. Genomic Epidemiology of Hypervirulent Serogroup W, ST-11 Neisseria meningitidis.

    Science.gov (United States)

    Mustapha, Mustapha M; Marsh, Jane W; Krauland, Mary G; Fernandez, Jorge O; de Lemos, Ana Paula S; Dunning Hotopp, Julie C; Wang, Xin; Mayer, Leonard W; Lawrence, Jeffrey G; Hiller, N Luisa; Harrison, Lee H

    2015-10-01

    Neisseria meningitidis is a leading bacterial cause of sepsis and meningitis globally with dynamic strain distribution over time. Beginning with an epidemic among Hajj pilgrims in 2000, serogroup W (W) sequence type (ST) 11 emerged as a leading cause of epidemic meningitis in the African 'meningitis belt' and endemic cases in South America, Europe, Middle East and China. Previous genotyping studies were unable to reliably discriminate sporadic W ST-11 strains in circulation since 1970 from the Hajj outbreak strain (Hajj clone). It is also unclear what proportion of more recent W ST-11 disease clusters are caused by direct descendants of the Hajj clone. Whole genome sequences of 270 meningococcal strains isolated from patients with invasive meningococcal disease globally from 1970 to 2013 were compared using whole genome phylogenetic and major antigen-encoding gene sequence analyses. We found that all W ST-11 strains were descendants of an ancestral strain that had undergone unique capsular switching events. The Hajj clone and its descendants were distinct from other W ST-11 strains in that they shared a common antigen gene profile and had undergone recombination involving virulence genes encoding factor H binding protein, nitric oxide reductase, and nitrite reductase. These data demonstrate that recent acquisition of a distinct antigen-encoding gene profile and variations in meningococcal virulence genes was associated with the emergence of the Hajj clone. Importantly, W ST-11 strains unrelated to the Hajj outbreak contribute a significant proportion of W ST-11 cases globally. This study helps illuminate genomic factors associated with meningococcal strain emergence and evolution.

  14. Neisseria meningitidis rifampicin resistant strains: analysis of protein differentially expressed

    Directory of Open Access Journals (Sweden)

    Schininà Maria

    2010-09-01

    Full Text Available Abstract Background Several mutations have been described as responsible for rifampicin resistance in Neisseria meningitidis. However, the intriguing question on why these strains are so rare remains open. The aim of this study was to investigate the protein content and to identify differential expression in specific proteins in two rifampicin resistant and one susceptible meningococci using two-dimensional electrophoresis (2-DE combined with mass spectrometry. Results In our experimental conditions, able to resolve soluble proteins with an isoelectric point between 4 and 7, twenty-three proteins have been found differentially expressed in the two resistant strains compared to the susceptible. Some of them, involved in the main metabolic pathways, showed an increased expression, mainly in the catabolism of pyruvate and in the tricarboxylic acid cycle. A decreased expression of proteins belonging to gene regulation and to those involved in the folding of polypeptides has also been observed. 2-DE analysis showed the presence of four proteins displaying a shift in their isoelectric point in both resistant strains, confirmed by the presence of amino acid changes in the sequence analysis, absent in the susceptible. Conclusions The analysis of differentially expressed proteins suggests that an intricate series of events occurs in N. meningitidis rifampicin resistant strains and the results here reported may be considered a starting point in understanding their decreased invasion capacity. In fact, they support the hypothesis that the presence of more than one protein differentially expressed, having a role in the metabolism of the meningococcus, influences its ability to infect and to spread in the population. Different reports have described and discussed how a drug resistant pathogen shows a high biological cost for survival and that may also explain why, for some pathogens, the rate of resistant organisms is relatively low considering the

  15. Persistence of Pathogenic and Non-Pathogenic Escherichia coli Strains in Various Tropical Agricultural Soils of India.

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    S Naganandhini

    Full Text Available The persistence of Shiga-like toxin producing E. coli (STEC strains in the agricultural soil creates serious threat to human health through fresh vegetables growing on them. However, the survival of STEC strains in Indian tropical soils is not yet understood thoroughly. Additionally how the survival of STEC strain in soil diverges with non-pathogenic and genetically modified E. coli strains is also not yet assessed. Hence in the present study, the survival pattern of STEC strain (O157-TNAU was compared with non-pathogenic (MTCC433 and genetically modified (DH5α strains on different tropical agricultural soils and on a vegetable growing medium, cocopeat under controlled condition. The survival pattern clearly discriminated DH5α from MTCC433 and O157-TNAU, which had shorter life (40 days than those compared (60 days. Similarly, among the soils assessed, the red laterite and tropical latosol supported longer survival of O157-TNAU and MTCC433 as compared to wetland and black cotton soils. In cocopeat, O157 recorded significantly longer survival than other two strains. The survival data were successfully analyzed using Double-Weibull model and the modeling parameters were correlated with soil physico-chemical and biological properties using principal component analysis (PCA. The PCA of all the three strains revealed that pH, microbial biomass carbon, dehydrogenase activity and available N and P contents of the soil decided the survival of E. coli strains in those soils and cocopeat. The present research work suggests that the survival of O157 differs in tropical Indian soils due to varied physico-chemical and biological properties and the survival is much shorter than those reported in temperate soils. As the survival pattern of non-pathogenic strain, MTCC433 is similar to O157-TNAU in tropical soils, the former can be used as safe model organism for open field studies.

  16. Comparative Analyses of Nonpathogenic, Opportunistic, and Totally Pathogenic Mycobacteria Reveal Genomic and Biochemical Variabilities and Highlight the Survival Attributes of Mycobacterium tuberculosis

    Science.gov (United States)

    Singh, Yadvir; Kohli, Sakshi; Ahmad, Javeed; Ehtesham, Nasreen Z.; Tyagi, Anil K.

    2014-01-01

    ABSTRACT Mycobacterial evolution involves various processes, such as genome reduction, gene cooption, and critical gene acquisition. Our comparative genome size analysis of 44 mycobacterial genomes revealed that the nonpathogenic (NP) genomes were bigger than those of opportunistic (OP) or totally pathogenic (TP) mycobacteria, with the TP genomes being smaller yet variable in size—their genomic plasticity reflected their ability to evolve and survive under various environmental conditions. From the 44 mycobacterial species, 13 species, representing TP, OP, and NP, were selected for genomic-relatedness analyses. Analysis of homologous protein-coding genes shared between Mycobacterium indicus pranii (NP), Mycobacterium intracellulare ATCC 13950 (OP), and Mycobacterium tuberculosis H37Rv (TP) revealed that 4,995 (i.e., ~95%) M. indicaus pranii proteins have homology with M. intracellulare, whereas the homologies among M. indicus pranii, M. intracellulare ATCC 13950, and M. tuberculosis H37Rv were significantly lower. A total of 4,153 (~79%) M. indicus pranii proteins and 4,093 (~79%) M. intracellulare ATCC 13950 proteins exhibited homology with the M. tuberculosis H37Rv proteome, while 3,301 (~82%) and 3,295 (~82%) M. tuberculosis H37Rv proteins showed homology with M. indicus pranii and M. intracellulare ATCC 13950 proteomes, respectively. Comparative metabolic pathway analyses of TP/OP/NP mycobacteria showed enzymatic plasticity between M. indicus pranii (NP) and M. intracellulare ATCC 13950 (OP), Mycobacterium avium 104 (OP), and M. tuberculosis H37Rv (TP). Mycobacterium tuberculosis seems to have acquired novel alternate pathways with possible roles in metabolism, host-pathogen interactions, virulence, and intracellular survival, and by implication some of these could be potential drug targets. PMID:25370496

  17. Activation of Exogenous Fatty Acids to Acyl-Acyl Carrier Protein Cannot Bypass FabI Inhibition in Neisseria*

    Science.gov (United States)

    Yao, Jiangwei; Bruhn, David F.; Frank, Matthew W.; Lee, Richard E.; Rock, Charles O.

    2016-01-01

    Neisseria is a Gram-negative pathogen with phospholipids composed of straight chain saturated and monounsaturated fatty acids, the ability to incorporate exogenous fatty acids, and lipopolysaccharides that are not essential. The FabI inhibitor, AFN-1252, was deployed as a chemical biology tool to determine whether Neisseria can bypass the inhibition of fatty acid synthesis by incorporating exogenous fatty acids. Neisseria encodes a functional FabI that was potently inhibited by AFN-1252. AFN-1252 caused a dose-dependent inhibition of fatty acid synthesis in growing Neisseria, a delayed inhibition of growth phenotype, and minimal inhibition of DNA, RNA, and protein synthesis, showing that its mode of action is through inhibiting fatty acid synthesis. Isotopic fatty acid labeling experiments showed that Neisseria encodes the ability to incorporate exogenous fatty acids into its phospholipids by an acyl-acyl carrier protein-dependent pathway. However, AFN-1252 remained an effective antibacterial when Neisseria were supplemented with exogenous fatty acids. These results demonstrate that extracellular fatty acids are activated by an acyl-acyl carrier protein synthetase (AasN) and validate type II fatty acid synthesis (FabI) as a therapeutic target against Neisseria. PMID:26567338

  18. Neisseria gonorrhoeae strain with reduced susceptibilities to extended-spectrum cephalosporins.

    Science.gov (United States)

    Nguyen, Duylinh; Gose, Severin; Castro, Lina; Chung, Kathleen; Bernstein, Kyle; Samuel, Micheal; Bauer, Heidi; Pandori, Mark

    2014-07-01

    The spread of Neisseria gonorrhoeae strains with reduced susceptibility to extended-spectrum cephalosporins is an increasing public health threat. Using Etest and multiantigen sequence typing, we detected sequence type 1407, which is associated with reduced susceptibilities to extended-spectrum cephalosporins, in 4 major populated regions in California, USA, in 2012.

  19. Neisseria meningitidis ST11 Complex Isolates Associated with Nongonococcal Urethritis, Indiana, USA, 2015-2016.

    Science.gov (United States)

    Toh, Evelyn; Gangaiah, Dharanesh; Batteiger, Byron E; Williams, James A; Arno, Janet N; Tai, Albert; Batteiger, Teresa A; Nelson, David E

    2017-02-01

    At a clinic in Indianapolis, Indiana, USA, we observed an increase in Neisseria gonorrhoeae-negative men with suspected gonococcal urethritis who had urethral cultures positive for N. meningitidis. We describe genomes of 2 of these N. meningitidis sequence type 11 complex urethritis isolates. Clinical evidence suggests these isolates may represent an emerging urethrotropic clade.

  20. Survivors of septic shock caused by Neisseria meningitidis in childhood: psychosocial outcomes in young adulthood

    NARCIS (Netherlands)

    Vermunt, Lindy C.; Buysse, Corinne M.; Joosten, Koen F.; Duivenvoorden, Hugo J.; Hazelzet, Jan A.; Verhulst, Frank C.; Utens, Elisabeth M.

    2011-01-01

    To investigate long-term psychosocial outcomes in young adults who survived septic shock caused by Neisseria meningitidis (meningococcal septic shock) during childhood. A cross-sectional study. The psychological investigation took place in the department of Child and Adolescent Psychiatry of the

  1. Survivors of septic shock caused by Neisseria meningitidis in childhood : Psychosocial outcomes in young adulthood

    NARCIS (Netherlands)

    Vermunt, Lindy C.; Buysse, Corinne M.; Joosten, Koen F.; Duivenvoorden, Hugo J.; Hazelzet, Jan A.; Verhulst, Frank C.; Utens, Elisabeth M.

    Objective: To investigate long-term psychosocial outcomes in young adults who survived septic shock caused by Neisseria meningitidis (meningococcal septic shock) during childhood. Design: A cross-sectional study. Setting: The psychological investigation took place in the department of Child and

  2. Neisseria meningitidis ST11 Complex Isolates Associated with Nongonococcal Urethritis, Indiana, USA, 2015–2016

    Science.gov (United States)

    Toh, Evelyn; Gangaiah, Dharanesh; Batteiger, Byron E.; Williams, James A.; Arno, Janet N.; Tai, Albert; Batteiger, Teresa A.

    2017-01-01

    At a clinic in Indianapolis, Indiana, USA, we observed an increase in Neisseria gonorrhoeae–negative men with suspected gonococcal urethritis who had urethral cultures positive for N. meningitidis. We describe genomes of 2 of these N. meningitidis sequence type 11 complex urethritis isolates. Clinical evidence suggests these isolates may represent an emerging urethrotropic clade. PMID:28098538

  3. A first meningococcal meningitis case caused by serogroup Ⅹ Neisseria meningitidis strains in China

    Institute of Scientific and Technical Information of China (English)

    CHEN Chao; UANG Ying-chun; ZHANG Tie-gang; HE Jing-guo; WU Jiang; CHEN Li-juan; LIU Jun-feng; PANG Xing-huo; YANG Jie; SHAO Zhu-jun

    2008-01-01

    @@ Neisseria meningitidis is the leading cause of bacterial meningitis and classified into 13 serogroups based on the immunological reactivity of the capsular polysaccharide.1 Serogroups A,B,C,W135 and Y are the most common causes of meningitis.2

  4. 21 CFR 866.2410 - Culture medium for pathogenic Neisseria spp.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Culture medium for pathogenic Neisseria spp. 866.2410 Section 866.2410 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Microbiology Devices § 866.2410...

  5. Molecular basis of the amylose-like polymer formation catalyzed by Neisseria polysaccharea amylosucrase

    DEFF Research Database (Denmark)

    Albenne, Cécile; Skov, Lars; Mirza, Osman Asghar

    2004-01-01

    Amylosucrase from Neisseria polysaccharea is a remarkable transglucosidase from family 13 of the glycoside-hydrolases that synthesizes an insoluble amylose-like polymer from sucrose in the absence of any primer. Amylosucrase shares strong structural similarities with alpha-amylases. Exactly how...

  6. Fit genotypes and escape variants of subgroup III Neisseria meningitidis during three pandemics of epidemic meningitis

    NARCIS (Netherlands)

    Zhu, P.; van der Ende, A.; Falush, D.; Brieske, N.; Morelli, G.; Linz, B.; Popovic, T.; Schuurman, I. G.; Adegbola, R. A.; Zurth, K.; Gagneux, S.; Platonov, A. E.; Riou, J. Y.; Caugant, D. A.; Nicolas, P.; Achtman, M.

    2001-01-01

    The genetic variability at six polymorphic loci was examined within a global collection of 502 isolates of subgroup III, serogroup A Neisseria meningitidis. Nine "genoclouds" were identified, consisting of genotypes that were isolated repeatedly plus 48 descendent genotypes that were isolated

  7. Comparison of commercial diagnostic tests for identification of serogroup antigens of Neisseria meningitidis

    NARCIS (Netherlands)

    van der Ende, A.; Schuurman, I. G.; Hopman, C. T.; Fijen, C. A.; Dankert, J.

    1995-01-01

    In the study that is described the sensitivities and specificities of three commercial tests and the standard Reference Laboratory test, used since 1961, to identify Neisseria meningitidis serogroups were compared. The tests marketed by Difco, Murex/Wellcome, and Sanofi/Pasteur showed overall

  8. Comparison of four techniques for the confirmatory identification of Neisseria gonorrhoeae

    International Nuclear Information System (INIS)

    Jacobs, P.F.

    1980-01-01

    The authors have compared four assay techniques for the confirmatory identification of Neisseria gonorrhoeae. On of these is a radiometric assay, based on the measurement of liberated radiolabelled CO 2 from metabolized carbohydrates which have been tagged with 14 C. The assay uses glucose, maltose and fructose as its differentiating sugars, plus the ONPG reaction, and can be read in three hours. (Auth.)

  9. Towards an improved Neisseria meningitidis B vaccine: vesicular PorA formulations

    NARCIS (Netherlands)

    Arigita Maza, C. (Carmen)

    2003-01-01

    There is a great need for vaccines against Neisseria meningitidis serogroup B. This is especially important in Western European countries, were approximately two thirds of the cases of meningococcal disease can be attributed to serogroup B strains. Against this serogroup, traditional vaccines based

  10. Multiple mechanisms of phase variation of PorA in Neisseria meningitidis

    NARCIS (Netherlands)

    van der Ende, A.; Hopman, C. T.; Dankert, J.

    2000-01-01

    Previously, we reported that PorA expression in Neisseria meningitidis is modulated by variation in the length of the homopolymeric tract of guanidine residues between the -35 and -10 regions of the promoter or by deletion of porA. To reveal additional mechanisms of variation in PorA expression, the

  11. Celulitis por Neisseria meningitidis: comunicación de un caso

    OpenAIRE

    Lissarrague, Sabina; Bernstein, Judith Celina; Schell, Celia María; Stagnaro, J. P.; De Luca, María Marta; López, M.; Basualdo Farjat, Juan Ángel; Sparo, Mónica

    2017-01-01

    Objetivo: comunicar un caso de celulitis por Neisseria meningitidis en muslo izquierdo en un lactante atendido en el Hospital de Niños del Municipio de Tandil, Provincia de Buenos Aires e investigar la portación familiar de esta bacteria.

  12. Reproducibility Problems with the Abbott Laboratories LCx Assay for Chlamydia trachomatis and Neisseria gonorrhoeae

    OpenAIRE

    Gronowski, Ann M.; Copper, Susan; Baorto, David; Murray, Patrick R.

    2000-01-01

    This study demonstrates that significant reproducibility problems can occur during routine use of the Abbott Laboratories LCx assay for Chlamydia trachomatis and Neisseria gonorrhoeae. These problems can go undetected by the quality control procedures outlined in the manufacturer's package insert. We outline here procedures for detecting and preventing contamination and reproducibility problems.

  13. Genome sequence of Neisseria meningitidis serogroup B strain H44/76

    NARCIS (Netherlands)

    Piet, J. R.; Huis in 't Veld, R. A. G.; van Schaik, B. D. C.; van Kampen, A. H. C.; Baas, F.; van de Beek, D.; Pannekoek, Y.; van der Ende, A.

    2011-01-01

    Neisseria meningitidis is an obligate human pathogen. While it is a frequent commensal of the upper respiratory tract, in some individuals the bacterium spreads to the bloodstream, causing meningitis and/or sepsis, which are serious conditions with high morbidity and mortality. Here we report the

  14. The iron-regulated transcriptome and proteome of Neisseria meningitidis serogroup C

    Czech Academy of Sciences Publication Activity Database

    Basler, Marek; Linhartová, Irena; Halada, Petr; Novotná, Jana; Bezoušková, Silvia; Osička, Radim; Weiser, Jaroslav; Vohradský, Jiří; Šebo, Peter

    2006-01-01

    Roč. 6, č. 23 (2006), s. 6194-6206 ISSN 1615-9853 R&D Projects: GA ČR GA310/04/0804; GA MZe 1G46068 Institutional research plan: CEZ:AV0Z50200510 Keywords : iron regulation * Neisseria meningitidis * proteome Subject RIV: EE - Microbiology, Virology Impact factor: 5.735, year: 2006

  15. Neisseria meningitidis endocarditis: a case report and review of the literature.

    LENUS (Irish Health Repository)

    Ali, Mohammed

    2012-02-01

    Neisseria meningitidis is the leading cause of bacterial meningitis in children and young adults, with an overall mortality rate of up to 25%, but it is a rare cause of infective endocarditis. We present herein a case of N. meningitidis meningitis complicated with infective endocarditis.

  16. Neisseria meningitidis endocarditis: A case report and review of the literature.

    LENUS (Irish Health Repository)

    Ali, Mohammed

    2011-04-08

    Abstract Neisseria meningitidis is the leading cause of bacterial meningitis in children and young adults, with an overall mortality rate of up to 25%, but it is a rare cause of infective endocarditis. We present herein a case of N. meningitidis meningitis complicated with infective endocarditis.

  17. A probable prehistoric case of meningococcal disease from San Francisco Bay: Next generation sequencing of Neisseria meningitidis from dental calculus and osteological evidence.

    Science.gov (United States)

    Eerkens, Jelmer W; Nichols, Ruth V; Murray, Gemma G R; Perez, Katherine; Murga, Engel; Kaijankoski, Phil; Rosenthal, Jeffrey S; Engbring, Laurel; Shapiro, Beth

    2018-05-25

    Next Generation Sequencing (NGS) of ancient dental calculus samples from a prehistoric site in San Francisco Bay, CA-SCL-919, reveals a wide range of potentially pathogenic bacteria. One older adult woman, in particular, had high levels of Neisseria meningitidis and low levels of Haemophilus influenzae, species that were not observed in the calculus from three other individuals. Combined with the presence of incipient endocranial lesions and pronounced meningeal grooves, we interpret this as an ancient case of meningococcal disease. This disease afflicts millions around the globe today, but little is known about its (pre)history. With additional sampling, we suggest NGS of calculus offers an exciting new window into the evolutionary history of these bacterial species and their interactions with humans. Copyright © 2018 Elsevier Inc. All rights reserved.

  18. Standardization of Neisseria meningitidis Serogroup B Colorimetric Serum Bactericida Assay

    Science.gov (United States)

    Rodríguez, Tamara; Lastre, Miriam; Cedré, Barbara; Campo, Judith del; Bracho, Gustavo; Zayas, Caridad; Taboada, Carlos; Díaz, Miriam; Sierra, Gustavo; Pérez, Oliver

    2002-01-01

    The correlate of protection for serogroup B meningococci is not currently known, but for serogroup C it is believed to be the serum bactericidal assay (SBA). The current SBAs are labor intensive and the variations in protocols among different laboratories make interpretation of results difficult. A colorimetric SBA (cSBA), based on the ability of Neisseria meningitidis serogroup B to consume glucose, leading to acid production, was standardized by using group B strain Cu385-83 as the target. The cSBA results were compared to those obtained for a traditional colony-counting microassay (mSBA). Glucose and bromocresol purple pH indicator were added to the medium in order to estimate growth of cSBA target cell survivors through color change. Different variants of the assay parameters were optimized: growth of target cells (Mueller Hinton agar plates), target cell number (100 CFU/per well), and human complement source used at a final concentration of 25%. After the optimization, three other group B strains (H44/76, 490/91, and 511/91) were used as targets for the cSBA. The selection of the assay parameters and the standardization of cSBA were done with 13 sera from vaccinated volunteers. The titers were determined as the higher serum dilution that totally inhibited the bacterial growth marked by the color invariability of the pH indicator. This was detected visually as well as spectrophotometrically and was closely related to a significant difference in the growth of target cell survivors determined using Student’s t test. Intralaboratory reproducibility was ±1 dilution. The correlation between bactericidal median titers and specific immunoglobulin G serum concentration by enzyme immunoassay was high (r = 0.910, P < 0.01). The bactericidal titers generated by the cSBA and the mSBA were nearly identical, and there was a high correlation between the two assays (r = 0.974, P < 0.01). The standardized cSBA allows easy, fast, and efficient evaluation of samples. PMID

  19. Molecular epidemiology of Neisseria gonorrhoeae strains circulating in Indonesia using multi-locus variable number tandem repeat analysis (MLVA) and Neisseria gonorrhoeae multi-antigen sequence typing (NG-NAST) techniques

    NARCIS (Netherlands)

    Hananta, I. Putu Yuda; van Dam, Alje Pieter; Schim van der Loeff, Maarten Franciscus; Dierdorp, Mirjam; Wind, Carolien Marleen; Soebono, Hardyanto; de Vries, Henry John Christiaan; Bruisten, Sylvia Maria

    2018-01-01

    Background: Control of gonorrhea in resource-limited countries, such as Indonesia, is mostly unsuccessful. Examining Neisseria gonorrhoeae (Ng) transmission networks using strain typing might help prioritizing public health interventions. Methods: In 2014, urogenital Ng strains were isolated from

  20. Vaginal Lactobacilli Reduce Neisseria gonorrhoeae Viability through Multiple Strategies: An in Vitro Study

    Directory of Open Access Journals (Sweden)

    Claudio Foschi

    2017-12-01

    Full Text Available The emergence and spread of antimicrobial resistance in Neisseria gonorrhoeae (GC underline the need of “antibiotic-free” strategies for the control of gonorrhea. The aim of this study was to assess the anti-gonococcal activity of 14 vaginal Lactobacillus strains, belonging to different species (L. crispatus, L. gasseri, L. vaginalis, isolated from healthy pre-menopausal women. In particular, we performed “inhibition” experiments, evaluating the ability of both lactobacilli cells and culture supernatants in reducing GC viability, at two different contact times (7 and 60 min. First, we found that the acidic environment, associated to lactobacilli metabolism, is extremely effective in counteracting GC growth, in a pH- and time-dependent manner. Indeed, a complete abolishment of GC viability by lactobacilli supernatants was observed only for pH values < 4.0, even at short contact times. On the contrary, for higher pH values, no 100%-reduction of GC growth was reached at any contact time. Experiments with organic/inorganic acid solutions confirmed the strict correlation between the pH levels and the anti-gonococcal effect. In this context, the presence of lactate seemed to be crucial for the anti-gonococcal activity, especially for pH values in the range 4.4–5.3, indicating that the presence of H+ ions is necessary but not sufficient to kill gonococci. Moreover, experiments with buffered supernatants led to exclude a direct role in the GC killing by other bioactive molecules produced by lactobacilli. Second, we noticed that lactobacilli cells are able to reduce GC viability and to co-aggregate with gonococci. In this context, we demonstrated that released-surface components with biosurfactant properties, isolated from “highly-aggregating” lactobacilli, could affect GC viability. The antimicrobial potential of biosurfactants isolated from lactobacilli against pathogens has been largely investigated, but this is the first report about a

  1. Detection of Neisseria meningitidis in a paediatric patient with septic arthritis using multiplexed diagnostic PCR targeting meningitis/encephalitis (ME).

    LENUS (Irish Health Repository)

    O'Sullivan, Donnchadh

    2018-03-23

    Neisseria meningitidis is associated with meningitis and septicemia. Septic meningococcal arthritis is relatively uncommon and its diagnosis associated with clinical and microbiological challenges. Early recognition and treatment is required to prevent joint destruction.

  2. Structural, functional and immunogenic insights on Cu,Zn Superoxide Dismutase pathogenic virulence factors from Neisseria meningitidis and Brucella abortus

    Science.gov (United States)

    Bacterial pathogens Neisseria meningitidis and Brucella abortus pose threats to human and animal health worldwide, causing meningococcal disease and brucellosis, respectively. Mortality from acute N. meningitidis infections remains high despite antibiotics, and brucellosis presents alimentary and he...

  3. Laboratory Predictors of Meningococcal Disease And Vaccination in Children: studies on the host immune response against Neisseria meningitidis

    NARCIS (Netherlands)

    C.L. Vermont (Clementien)

    2004-01-01

    markdownabstract__Abstract__ Neisseria meningitidis is a gram-negative diplococcus which was first identified by Anton Weichselbaum in 1887. Strains of N. meningitidis can be classified into serogroups based upon the different composition of its capsular polysaccharide. Thirteen serogroups

  4. Fuzzy species among recombinogenic bacteria

    Directory of Open Access Journals (Sweden)

    Fraser Christophe

    2005-03-01

    Full Text Available Abstract Background It is a matter of ongoing debate whether a universal species concept is possible for bacteria. Indeed, it is not clear whether closely related isolates of bacteria typically form discrete genotypic clusters that can be assigned as species. The most challenging test of whether species can be clearly delineated is provided by analysis of large populations of closely-related, highly recombinogenic, bacteria that colonise the same body site. We have used concatenated sequences of seven house-keeping loci from 770 strains of 11 named Neisseria species, and phylogenetic trees, to investigate whether genotypic clusters can be resolved among these recombinogenic bacteria and, if so, the extent to which they correspond to named species. Results Alleles at individual loci were widely distributed among the named species but this distorting effect of recombination was largely buffered by using concatenated sequences, which resolved clusters corresponding to the three species most numerous in the sample, N. meningitidis, N. lactamica and N. gonorrhoeae. A few isolates arose from the branch that separated N. meningitidis from N. lactamica leading us to describe these species as 'fuzzy'. Conclusion A multilocus approach using large samples of closely related isolates delineates species even in the highly recombinogenic human Neisseria where individual loci are inadequate for the task. This approach should be applied by taxonomists to large samples of other groups of closely-related bacteria, and especially to those where species delineation has historically been difficult, to determine whether genotypic clusters can be delineated, and to guide the definition of species.

  5. Fastidious Gram-Negatives: Identification by the Vitek 2 Neisseria-Haemophilus Card and by Partial 16S rRNA Gene Sequencing Analysis.

    Science.gov (United States)

    Sönksen, Ute Wolff; Christensen, Jens Jørgen; Nielsen, Lisbeth; Hesselbjerg, Annemarie; Hansen, Dennis Schrøder; Bruun, Brita

    2010-12-31

    Taxonomy and identification of fastidious Gram negatives are evolving and challenging. We compared identifications achieved with the Vitek 2 Neisseria-Haemophilus (NH) card and partial 16S rRNA gene sequence (526 bp stretch) analysis with identifications obtained with extensive phenotypic characterization using 100 fastidious Gram negative bacteria. Seventy-five strains represented 21 of the 26 taxa included in the Vitek 2 NH database and 25 strains represented related species not included in the database. Of the 100 strains, 31 were the type strains of the species. Vitek 2 NH identification results: 48 of 75 database strains were correctly identified, 11 strains gave `low discrimination´, seven strains were unidentified, and nine strains were misidentified. Identification of 25 non-database strains resulted in 14 strains incorrectly identified as belonging to species in the database. Partial 16S rRNA gene sequence analysis results: For 76 strains phenotypic and sequencing identifications were identical, for 23 strains the sequencing identifications were either probable or possible, and for one strain only the genus was confirmed. Thus, the Vitek 2 NH system identifies most of the commonly occurring species included in the database. Some strains of rarely occurring species and strains of non-database species closely related to database species cause problems. Partial 16S rRNA gene sequence analysis performs well, but does not always suffice, additional phenotypical characterization being useful for final identification.

  6. Diagnosis of Neisseria gonorrhoeae among pregnant women by culture method and PCR on cppB gene

    Directory of Open Access Journals (Sweden)

    Jalal Mardaneh

    2013-11-01

    Full Text Available Background: Neisseria gonorrhoeae is a human obligate pathogen and the etiological agent of gonorrhea. Health irreparable complications resulting from gonorrhea disease occur mainly in pregnant women and neonates. Aim of this study was diagnosis of Neisseria gonorrhoeae among pregnant women with using culture and molecular method by amplification of cppB gene with PCR. Material and Methods: In this cross-sectional study, two endocervical swab specimens were obtained from 1100 pregnant women who referred to Shiraz Hospitals. Culture on nonselective and selective media and nucleic acid amplification test (NAAT were performed for detection of Neisseria gonorrhoeae cppB gene. Results: All endocervical swabs cultures on selective and nonselective media were negative for Neisseria gonorrhoeae. Among examined endocervical swabs, 13samples (1.18% were positive by nucleic acid amplification of Neisseria gonorrgoeae cppB gene. Conclusion: Negative results of culture and positive results of PCR in this study indicate that however culture is gold standard method for detection of Neisseria gonorrhoeae but due to bacterial autolysis, poor sampling techniques and improper specimen storage and transport, its value decline as compared with Nucleic acid amplification test (NAAT.

  7. The role of glyceraldehyde 3-phosphate dehydrogenase (GapA-1 in Neisseria meningitidis adherence to human cells

    Directory of Open Access Journals (Sweden)

    Wooldridge Karl G

    2010-11-01

    Full Text Available Abstract Background Glyceraldehyde 3-phosphate dehydrogenases (GAPDHs are cytoplasmic glycolytic enzymes, which although lacking identifiable secretion signals, have also been found localized to the surface of several bacteria (and some eukaryotic organisms; where in some cases they have been shown to contribute to the colonization and invasion of host tissues. Neisseria meningitidis is an obligate human nasopharyngeal commensal which can cause life-threatening infections including septicaemia and meningitis. N. meningitidis has two genes, gapA-1 and gapA-2, encoding GAPDH enzymes. GapA-1 has previously been shown to be up-regulated on bacterial contact with host epithelial cells and is accessible to antibodies on the surface of capsule-permeabilized meningococcal cells. The aims of this study were: 1 to determine whether GapA-1 was expressed across different strains of N. meningitidis; 2 to determine whether GapA-1 surface accessibility to antibodies was dependant on the presence of capsule; 3 to determine whether GapA-1 can influence the interaction of meningococci and host cells, particularly in the key stages of adhesion and invasion. Results In this study, expression of GapA-1 was shown to be well conserved across diverse isolates of Neisseria species. Flow cytometry confirmed that GapA-1 could be detected on the cell surface, but only in a siaD-knockout (capsule-deficient background, suggesting that GapA-1 is inaccessible to antibody in in vitro-grown encapsulated meningococci. The role of GapA-1 in meningococcal pathogenesis was addressed by mutational analysis and functional complementation. Loss of GapA-1 did not affect the growth of the bacterium in vitro. However, a GapA-1 deficient mutant showed a significant reduction in adhesion to human epithelial and endothelial cells compared to the wild-type and complemented mutant. A similar reduction in adhesion levels was also apparent between a siaD-deficient meningococcal strain and an

  8. Pathogenic and Nonpathogenic Lifestyles in Colletotrichum acutatum from Strawberry and Other Plants.

    Science.gov (United States)

    Freeman, S; Horowitz, S; Sharon, A

    2001-10-01

    ABSTRACT Anthracnose is one of the major fungal diseases of strawberry occurring worldwide. In Israel, the disease is caused primarily by the species Colletotrichum acutatum. The pathogen causes black spot on fruit, root necrosis, and crown rot resulting in mortality of transplants in the field. The host range and specificity of C. acutatum from strawberry was examined on pepper, eggplant, tomato, bean, and strawberry under greenhouse conditions. The fungus was recovered from all plant species over a 3-month period but caused disease symptoms only on strawberry. Epiphytic and endophytic (colonization) fungal growth in the different plant species was confirmed by reisolation from leaf tissues and by polymerase chain reaction (PCR)-specific primer amplification. C. acutatum was also isolated from healthy looking, asymptomatic plants of the weed genera Vicia and Conyza. Isolates that were recovered from the weeds caused disease symptoms on strawberry and were positively identified as C. acutatum by PCR. The habitation of a large number of plant species, including weeds, by C. acutatum suggests that, although it causes disease only on strawberry and anemone in Israel, this fungus can persist on many other plant species. Therefore, plants that are not considered hosts of C. acutatum may serve as a potential inoculum source for strawberry infection and permit survival of the pathogen between seasons.

  9. Investigations on the effects of triazole group fungicides on some important antagonistic fungi and non-pathogen Fusarium oxysporum (Schlecht) in vitro.

    OpenAIRE

    Demirci, A.; Katırcıoğlu, Z.; Demirci, F.

    2008-01-01

    The effects of eight triazole fungicides (cyproconazole, diniconazole, flusilazole hexaconazole, myclobutanil, penconazole, tebuconazole and triticinazole) on some important antagonistic fungi [Trichoderma harzianum (Rifai), T. viride (Pers. ex Gray), T. pseudokoningii (Rifai), T. hamatum (Bonard), Gliociadium viride (Matrouchot), Aspergillus niger (Tieghem), Penicillium verrııcosum (Dierckx)] and non-pathogen Fusarium oxysporum (Schlecht) were investigated on PDA in vitro. EC5 0 values ...

  10. Investigations on the effects of triazole group fungicides on some important antagonistic fungi and non-pathogen Fusarium oxysporum (Schlecht) in vitro.

    OpenAIRE

    Demirci, A.; Katırcıoğlu, Z.; Demirci, F.

    2008-01-01

    The effects of eight triazole fungicides (cyproconazole, diniconazole, flusilazole hexaconazole, myclobutanil, penconazole, tebuconazole and triticinazole) on some important antagonistic fungi [Trichoderma harzianum (Rifai), T. viride (Pers. ex Gray), T. pseudokoningii (Rifai), T. hamatum (Bonard), Gliociadium viride (Matrouchot), Aspergillus niger (Tieghem), Penicillium verrııcosum (Dierckx)] and non-pathogen Fusarium oxysporum (Schlecht) were investigated on PDA in vitro. EC5 0 values ...

  11. Resource capture and competitive ability of non-pathogenic Pseudogymnoascus spp. and P. destructans, the cause of white-nose syndrome in bats.

    Directory of Open Access Journals (Sweden)

    Michael B Wilson

    Full Text Available White-nose syndrome (WNS is a devastating fungal disease that has been causing the mass mortality of hibernating bats in North America since 2006 and is caused by the psychrophilic dermatophyte Pseudogymnoascus destructans. Infected bats shed conidia into hibernaculum sediments and surfaces, but it is unknown if P. destructans can form stable, reproductive populations outside its bat hosts. Previous studies have found non-pathogenic Pseudogymnoascus in bat hibernacula, and these fungi may provide insight into the natural history of P. destructans. We compared the relatedness, resource capture, and competitive ability of non-pathogenic Pseudogymnoascus isolates with P. destructans to determine if they have similar adaptations for survival in hibernacula sediment. All non-pathogenic Pseudogymnoascus isolates grew faster, utilized a broader range of substrates with higher efficiency, and were generally more resistant to antifungals compared to P. destructans. All isolates also showed the ability to displace P. destructans in co-culture assays, but only some produced extractible antifungal metabolites. These results suggest that P. destructans would perform poorly in the same environmental niche as non-pathogenic Pseudogymnoascus, and must have an alternative saprophytic survival strategy if it establishes active populations in hibernaculum sediment and non-host surfaces.

  12. Resource capture and competitive ability of non-pathogenic Pseudogymnoascus spp. and P. destructans, the cause of white-nose syndrome in bats.

    Science.gov (United States)

    Wilson, Michael B; Held, Benjamin W; Freiborg, Amanda H; Blanchette, Robert A; Salomon, Christine E

    2017-01-01

    White-nose syndrome (WNS) is a devastating fungal disease that has been causing the mass mortality of hibernating bats in North America since 2006 and is caused by the psychrophilic dermatophyte Pseudogymnoascus destructans. Infected bats shed conidia into hibernaculum sediments and surfaces, but it is unknown if P. destructans can form stable, reproductive populations outside its bat hosts. Previous studies have found non-pathogenic Pseudogymnoascus in bat hibernacula, and these fungi may provide insight into the natural history of P. destructans. We compared the relatedness, resource capture, and competitive ability of non-pathogenic Pseudogymnoascus isolates with P. destructans to determine if they have similar adaptations for survival in hibernacula sediment. All non-pathogenic Pseudogymnoascus isolates grew faster, utilized a broader range of substrates with higher efficiency, and were generally more resistant to antifungals compared to P. destructans. All isolates also showed the ability to displace P. destructans in co-culture assays, but only some produced extractible antifungal metabolites. These results suggest that P. destructans would perform poorly in the same environmental niche as non-pathogenic Pseudogymnoascus, and must have an alternative saprophytic survival strategy if it establishes active populations in hibernaculum sediment and non-host surfaces.

  13. Genomic Characterization of Urethritis-Associated Neisseria meningitidis Shows that a Wide Range of N. meningitidis Strains Can Cause Urethritis.

    Science.gov (United States)

    Ma, Kevin C; Unemo, Magnus; Jeverica, Samo; Kirkcaldy, Robert D; Takahashi, Hideyuki; Ohnishi, Makoto; Grad, Yonatan H

    2017-12-01

    Neisseria meningitidis , typically a resident of the oro- or nasopharynx and the causative agent of meningococcal meningitis and meningococcemia, is capable of invading and colonizing the urogenital tract. This can result in urethritis, akin to the syndrome caused by its sister species, N. gonorrhoeae , the etiologic agent of gonorrhea. Recently, meningococcal strains associated with outbreaks of urethritis were reported to share genetic characteristics with the gonococcus, raising the question of the extent to which these strains contain features that promote adaptation to the genitourinary niche, making them gonococcus-like and distinguishing them from other N. meningitidis strains. Here, we analyzed the genomes of 39 diverse N. meningitidis isolates associated with urethritis, collected independently over a decade and across three continents. In particular, we characterized the diversity of the nitrite reductase gene ( aniA ), the factor H-binding protein gene ( fHbp ), and the capsule biosynthetic locus, all of which are loci previously suggested to be associated with urogenital colonization. We observed notable diversity, including frameshift variants, in aniA and fHbp and the presence of intact, disrupted, and absent capsule biosynthetic genes, indicating that urogenital colonization and urethritis caused by N. meningitidis are possible across a range of meningococcal genotypes. Previously identified allelic patterns in urethritis-associated N. meningitidis strains may reflect genetic diversity in the underlying meningococcal population rather than novel adaptation to the urogenital tract. Copyright © 2017 American Society for Microbiology.

  14. Epidemiological markers in Neisseria meningitidis: an estimate of the performance of genotyping vs phenotyping

    DEFF Research Database (Denmark)

    Weis, N; Lind, I

    1998-01-01

    In order to estimate the performance of genotypic vs phenotypic characterization of Neisseria meningitidis, 2 methods, DNA fingerprinting and multilocus enzyme electrophoresis (MEE), were assessed as regards applicability, reproducibility and discriminating capacity. 50 serogroup B and 52 serogroup...... C Neisseria meningitidis strains from 96 patients with meningococcal disease and 22 serogroup C strains from healthy carriers were investigated. Both methods were 100% applicable to meningococcal strains and results of DNA fingerprinting as well as of MEE were reproducible. The number of types...... defined by DNA fingerprinting and MEE as compared to that defined by phenotypic characteristics (serogroup, serotype, serosubtype and sulphonamide resistance) was as follows: for serogroup B strains from patients, 11 and 12 vs 8; for serogroup C strains from patients, 10 and 15 vs 8; and for serogroup C...

  15. Infective endocarditis caused by Neisseria elongata on a native tricuspid valve and confirmed by DNA sequencing.

    Science.gov (United States)

    Yoo, Yeon Pyo; Kang, Ki-Woon; Yoon, Hyeon Soo; Yoo, Seungmin; Lee, Myung-Shin

    2014-04-01

    Neisseria elongata, a common oral bacterium, has been recognized as a cause of infections such as infective endocarditis, septicemia, and osteomyelitis. Neisseria-induced infective endocarditis, although infrequently reported, typically arises after dental procedures. Without antibiotic therapy, its complications can be severe. We report the case of a 27-year-old man who presented with fever, severe dyspnea, and a leg abscess from cellulitis. An echocardiogram showed a vegetation-like echogenic structure on the septal leaflet of the patient's native tricuspid valve, and an insignificant Gerbode defect. Three blood cultures grew gram-negative, antibiotic-susceptible coccobacilli that were confirmed to be N. elongata. Subsequent DNA sequencing conclusively isolated N. elongata subsp nitroreducens as the organism responsible for the infective endocarditis. The patient recovered after 21 days of antibiotic therapy. In addition to the patient's unusual case, we discuss the nature and isolation of N. elongata and its subspecies.

  16. Chlamydia trachomatis Serovar Distribution and Neisseria gonorrhoeae Coinfection in Male Patients with Urethritis in Greece▿

    Science.gov (United States)

    Papadogeorgakis, Helen; Pittaras, Theodore E.; Papaparaskevas, Joseph; Pitiriga, Vassiliki; Katsambas, Andreas; Tsakris, Athanassios

    2010-01-01

    The distribution of Chlamydia trachomatis serovars and Neisseria gonorrhoeae coinfection was studied in a group of 100 C. trachomatis-positive males with urethritis in Greece. The serovar distribution revealed that apart from the predominant worldwide types E and F, the relatively uncommon type G is also prevalent. Gonococcal coinfection was frequent (30%) and was associated with genovariant Ja (75%, P = 0.008). PMID:20357220

  17. Resurgence of Neisseria meningitidis serogroup W ST-11 (cc11) in Madagascar, 2015-2016.

    Science.gov (United States)

    Rasoanandrasana, Saïda; Raberahona, Mihaja; Milenkov, Milen; Rakotomahefa Narison, Mbolanirina Lala; Ranaivo Rabetokotany, Felana; Rakotovao, Luc; Randria, Mamy Jean de Dieu; Hong, Eva; Paranhos-Baccalà, Glaucia; Taha, Muhamed-Kheir; Rakoto-Andrianarivelo, Mala

    2017-02-01

    The resurgence of invasive meningococcal disease caused by Neisseria meningitidis serogroup W with sequence type ST-11 (cc11) was observed in Madagascar in 2015-2016. Three cases were investigated in this study. Molecular characterization of the strains suggests the local transmission of a single genotype that may have been circulating for years. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  18. Enhancement of recovery of Neisseria meningitidis by gelatin in blood culture media.

    OpenAIRE

    Pai, C H; Sorger, S

    1981-01-01

    The efficacy of gelatin for the recovery of Neisseria meningitidis from blood cultures was evaluated in a clinical setting. The organism was isolated from seven patients with meningococcal infections in blood culture media containing 1% gelatin. In contrast, only two blood cultures from these patients were positive in media without gelatin (P less than 0.05). Gelatin did not influence the recovery of other organisms isolated during this study. Conventional blood culture media may be supplemen...

  19. Crystallographic characterization of the outer membrane lipoprotein FrpD from Neisseria meningitidis

    Czech Academy of Sciences Publication Activity Database

    Sviridova, Ekaterina; Bumba, Ladislav; Řezáčová, Pavlína; Veverka, Václav; Šebo, Peter; Kutá-Smatanová, Ivana

    2015-01-01

    Roč. 22, č. 1 (2015), s. 57-58 ISSN 1211-5894. [Discussions in Structural Molecular Biology. Annual Meeting of the Czech Society for Structural Biology /13./. 19.03.2015-21.03.2015, Nové Hrady] R&D Projects: GA ČR(CZ) GAP207/11/0717; GA MŠk(CZ) LC06010 Institutional support: RVO:61388963 ; RVO:67179843 ; RVO:61388971 Keywords : FrpD * Neisseria meningitidis Subject RIV: CE - Biochemistry

  20. Backbone resonance assignments of the outer membrane lipoprotein FrpD from Neisseria meningitidis

    Czech Academy of Sciences Publication Activity Database

    Bumba, Ladislav; Sviridova, E.; Kutá-Smatanová, Ivana; Řezáčová, Pavlína; Veverka, Václav

    2014-01-01

    Roč. 8, č. 1 (2014), s. 53-55 ISSN 1874-2718 R&D Projects: GA ČR(CZ) GAP207/11/0717; GA MŠk(CZ) LK11205 Institutional support: RVO:61388963 ; RVO:61388971 ; RVO:67179843 Keywords : Neisseria meningitidis * FrpC * FrpD * backbone assignments * NMR * iron-regulated protein Subject RIV: CE - Biochemistry Impact factor: 0.760, year: 2014

  1. Chlamydia trachomatis and Neisseria gonorrhoeae in asymptomatic family planning patients in rural New Mexico.

    OpenAIRE

    Bell, T A; Ebenezer, M R

    1989-01-01

    We tested 98 asymptomatic women seen in state-funded contraception clinics in rural New Mexico. A fluorescein-conjugated monoclonal antibody stain revealed Chlamydia trachomatis infection in 25% of asymptomatic unmarried women and 3% of married women (P = .03). Neisseria gonorrhoeae was detected in only one woman. As in urban clinics providing contraception, the prevalence of gonorrhea is rare in rural New Mexico, but chlamydial infections are common in young unmarried women.

  2. The Neisseria meningitidis Outer Membrane Lipoprotein FrpD Binds the RTX Protein FrpC

    Czech Academy of Sciences Publication Activity Database

    Procházková, Kateřina; Osička, Radim; Linhartová, Irena; Halada, Petr; Šulc, Miroslav; Šebo, Peter

    2005-01-01

    Roč. 280, č. 5 (2005), s. 3251-3258 ISSN 0021-9258 R&D Projects: GA ČR GA310/02/1448 Grant - others:Howard Hughes Medical Institute International Research Scholarship Award 55000334 Institutional research plan: CEZ:AV0Z50200510 Keywords : neisseria meningitidis * FrpD * FrpC Subject RIV: EE - Microbiology, Virology Impact factor: 5.854, year: 2005

  3. Tetracycline resistance and TetM in oral anaerobic bacteria and Neisseria perflava-N. sicca.

    OpenAIRE

    Roberts, M C; Moncla, B J

    1988-01-01

    Tetracycline-resistant organisms isolated from six patients with periodontal disease included Bacteroides spp., Eubacterium spp., Fusobacterium nucleatum, Neisseria perflava-N. sicca, Peptostreptococcus anaerobius, Veillonella parvula, and facultative streptococci. All but the Bacteroides spp. and Eubacterium spp. hybridized with the TetM determinant. An additional 417 bacterial strains were screened, and 4% of both the oral streptococci and the Fusobacterium spp. hybridized with the TetM probe.

  4. Resistencia de Neisseria gonorrhoeae a ciprofloxacina según hábitos sexuales Ciprofloxacin resistance of Neisseria gonorrhoeae according to sexual habits

    Directory of Open Access Journals (Sweden)

    Susana García

    2008-10-01

    Full Text Available En la Argentina los primeros hallazgos de Neisseria gonorrhoeae resistentes a las fluorquinolonas se documentaron en el año 2000. Desde enero de 2005 hasta junio de 2007, se evaluaron 595 hombres que tienen sexo con hombres (HSH y 571 varones heterosexuales para investigar la presencia de N. gonorrhoeae y la resistencia a los antimicrobianos. La prevalencia de gonorrea en HSH y varones heterosexuales fue 0.091(91/1000 en ambos grupos y el % de N. gonorrhoeae resistente a ciprofloxacina (NGRC fue 20.0% y 3.8% respectivamente (p: 0.0416. Trece de 106 aislamientos fueron NGRC, correspondieron a 11 HSH y 2 varones heterosexuales. Seis HSH presentaron uretritis, uno de ellos con localización simultánea en recto y cinco pacientes fueron asintomáticos (recto, 2; faringe, 2; uretra, 1. No se pudo demostrar relación epidemiológica entre ellos. Dos varones heterosexuales presentaron uretritis. Los 8 pacientes sintomáticos fueron tratados empíricamente con ciprofloxacina y se documentó fracaso de tratamiento. Estos y los portadores de NGRC recibieron tratamiento con 500 mg de ceftriaxona IM. Los controles postratamiento demostraron la erradicación del microorganismo. Los aislamientos de NGRC presentaron CIM de ciprofloxacina entre 2 y 32 µg/ml, todos fueron beta-lactamasa negativos, 4/13 presentaron resistencia cromosómica a penicilina (CIM= 1 µg/ml, y los rangos de CIM (µg/ml para los siguientes antibióticos fueron: penicilina: 0.016-1; tetraciclina: 0.125-2; ceftriaxona: 0.004-0.008; eritromicina: 0.032-2; azitromicina: 0.032-0.5; espectinomicina: 8-32. Dado el elevado porcentaje de aislamientos de NGRC en HSH en nuestro hospital, debería utilizarse otro antimicrobiano para el tratamiento empírico en estos pacientes.The first isolates of Neisseria gonorrhoeae resistant to fluorquinolones in Argentina were reported in 2000. Since January 2005 to June 2007 Neisseria gonorrhoeae was studied in 595 men who have sex with men (MSM and 571

  5. Longitudinal Comparison of Antibiotic Resistance in Diarrheagenic and Non-pathogenic E. coli from Young Tanzanian Children

    Directory of Open Access Journals (Sweden)

    Jessica Couvillion Seidman

    2016-09-01

    Full Text Available Enteroaggregative, enteropathogenic, and enterotoxigenic E. coli contribute significantly to the burden of diarrheal infections particularly in developing countries. Antibiotic resistance is increasingly common among bacterial pathogens including pathogenic E. coli. We assessed the relationship between pathogenic E. coli carriage and resistance to 6 antibiotics in E. coli isolated from young children in rural Tanzania. We surveyed temporal stability in antibiotic resistance in 2492 E. coli isolated from fecal samples obtained from young children in rural Tanzania collected over a 6 month period. Enteroaggregative, enteropathogenic, and enterotoxigenic E. coli contribute significantly to the burden of diarrheal infections particularly in developing countries. Antibiotic resistance is increasingly common among bacterial pathogens including pathogenic E. coli. We assessed the relationship between pathogenic E. coli carriage and resistance to 6 antibiotics in E. coli isolated from young children in rural Tanzania. We surveyed temporal stability in antibiotic resistance in 2492 E. coli isolated from fecal samples obtained from young children in rural Tanzania collected over a 6 month period. Approximately half of the 377 children sampled were exposed to an azithromycin mass treatment program for trachoma control and half resided in control villages. Children were sampled at baseline, 1-, 3- and 6 months following azithromycin treatment. We compared resistance to 6 antibiotics in pathogenic and non-pathogenic strains at the population level, within fecal specimens, and within individuals over time using chi-square tests, paired odds ratios, and logistic regression, respectively. Resistance to ampicillin and trimethoprim/sulfamethoxazole was highly prevalent (>65%. Resistance to 5 of 6 antibiotics tested and multi-drug resistance occurred more frequently in pathogenic isolates (p≤0.001 within fecal specimens and overall. Azithromycin mass treatment

  6. Non-pathogenic rhizobacteria interfere with the attraction of parasitoids to aphid-induced plant volatiles via jasmonic acid signalling.

    Science.gov (United States)

    Pineda, Ana; Soler, Roxina; Weldegergis, Berhane T; Shimwela, Mpoki M; VAN Loon, Joop J A; Dicke, Marcel

    2013-02-01

    Beneficial soil-borne microbes, such as mycorrhizal fungi or rhizobacteria, can affect the interactions of plants with aboveground insects at several trophic levels. While the mechanisms of interactions with herbivorous insects, that is, the second trophic level, are starting to be understood, it remains unknown how plants mediate the interactions between soil microbes and carnivorous insects, that is, the third trophic level. Using Arabidopsis thaliana Col-0 and the aphid Myzus persicae, we evaluate here the underlying mechanisms involved in the plant-mediated interaction between the non-pathogenic rhizobacterium Pseudomonas fluorescens and the parasitoid Diaeretiella rapae, by combining ecological, chemical and molecular approaches. Rhizobacterial colonization modifies the composition of the blend of herbivore-induced plant volatiles. The volatile blend from rhizobacteria-treated aphid-infested plants is less attractive to an aphid parasitoid, in terms of both olfactory preference behaviour and oviposition, than the volatile blend from aphid-infested plants without rhizobacteria. Importantly, the effect of rhizobacteria on both the emission of herbivore-induced volatiles and parasitoid response to aphid-infested plants is lost in an Arabidopsis mutant (aos/dde2-2) that is impaired in jasmonic acid production. By modifying the blend of herbivore-induced plant volatiles that depend on the jasmonic acid-signalling pathway, root-colonizing microbes interfere with the attraction of parasitoids of leaf herbivores. © 2012 Blackwell Publishing Ltd.

  7. Prevention of immunodeficiency virus induced CD4+ T-cell depletion by prior infection with a non-pathogenic virus

    International Nuclear Information System (INIS)

    TerWee, Julie A.; Carlson, Jennifer K.; Sprague, Wendy S.; Sondgeroth, Kerry S.; Shropshire, Sarah B.; Troyer, Jennifer L.; VandeWoude, Sue

    2008-01-01

    Immune dysregulation initiated by a profound loss of CD4+ T-cells is fundamental to HIV-induced pathogenesis. Infection of domestic cats with a non-pathogenic lentivirus prevalent in the puma (puma lentivirus, PLV or FIV PCO ) prevented peripheral blood CD4+ T-cell depletion caused by subsequent virulent FIV infection. Maintenance of this critical population was not associated with a significant decrease in FIV viremia, lending support to the hypothesis that direct viral cytopathic effect is not the primary cause of immunodeficiency. Although this approach was analogous to immunization with a modified live vaccine, correlates of immunity such as a serum-neutralizing antibody or virus-specific T-cell proliferative response were not found in protected animals. Differences in cytokine transcription profile, most notably in interferon gamma, were observed between the protected and unprotected groups. These data provide support for the importance of non-adaptive enhancement of the immune response in the prevention of CD4+ T-cell loss

  8. Green synthesis of highly stabilized nanocrystalline silver particles by a non-pathogenic and agriculturally important fungus T. asperellum

    Energy Technology Data Exchange (ETDEWEB)

    Mukherjee, P; Mukherjee, P K; Kale, S P [Nuclear Agriculture and Biotechnology Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Roy, M; Mandal, B P; Tyagi, A K [Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Dey, G K [Material Science Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Ghatak, J [Institute of Physics, Bhubaneswar 751005 (India)], E-mail: sharadkale@gmail.com

    2008-02-20

    A controlled and up-scalable biosynthetic route to nanocrystalline silver particles with well-defined morphology using cell-free aqueous filtrate of a non-pathogenic and commercially viable biocontrol agent Trichoderma asperellum is being reported for the first time. A transparent solution of the cell-free filtrate of Trichoderma asperellum containing 1 mM AgNO{sub 3} turns progressively dark brown within 5 d of incubation at 25 deg. C. The kinetics of the reaction was studied using UV-vis spectroscopy. An intense surface plasmon resonance band at {approx}410 nm in the UV-vis spectrum clearly reveals the formation of silver nanoparticles. The size of the silver particles using TEM and XRD studies is found to be in the range 13-18 nm. These nanoparticles are found to be highly stable and even after prolonged storage for over 6 months they do not show significant aggregation. A plausible mechanism behind the formation of silver nanoparticles and their stabilization via capping has been investigated using FTIR and surface-enhanced resonance Raman spectroscopy.

  9. Efficacy of the Non-Pathogenic Agrobacterium Strains K84 and K1026 against Crown Gall in Tunisia

    Directory of Open Access Journals (Sweden)

    A. Rhouma

    2004-08-01

    Full Text Available The non-pathogenic Agrobacterium radiobacter strain K84 and its genetically modified (GEM strain K1026 were tested for their effectiveness against local Tunisian strains and two reference strains (C58 and B6 of the crown gall bacterium Agrobacterium tumefaciens. Tests in planta were carried out on herbaceous plants (tomato and tagetes and on some sensitive rootstocks (bitter almond, peach almond hybrid GF677 and quince BA29. In vitro tests showed that both K84 and K1026 were effective and that the difference between these strains was not statistically significant. On tomato and tagetes, strain K84 was effective against all crown gall isolates with the exception of the A. tumefaciens reference strain B6. GEM strain K1026 was very effective against all isolates from Tunisia and against the reference strains. Both antagonistic strains significantly reduced the percentage of galled plants as well as the number of galls per plant. Under field conditions, both antagonists controlled crown gall effectively. Best results were obtained on the bitter almond-tree rootstock. Antagonist effectiveness was less evident on quince BA29 and peach almond GF677 rootstocks. The genetically modified strain K1026 is of interest in controlling crown gall disease in Tunisia.

  10. Green synthesis of highly stabilized nanocrystalline silver particles by a non-pathogenic and agriculturally important fungus T. asperellum

    International Nuclear Information System (INIS)

    Mukherjee, P; Mukherjee, P K; Kale, S P; Roy, M; Mandal, B P; Tyagi, A K; Dey, G K; Ghatak, J

    2008-01-01

    A controlled and up-scalable biosynthetic route to nanocrystalline silver particles with well-defined morphology using cell-free aqueous filtrate of a non-pathogenic and commercially viable biocontrol agent Trichoderma asperellum is being reported for the first time. A transparent solution of the cell-free filtrate of Trichoderma asperellum containing 1 mM AgNO 3 turns progressively dark brown within 5 d of incubation at 25 deg. C. The kinetics of the reaction was studied using UV-vis spectroscopy. An intense surface plasmon resonance band at ∼410 nm in the UV-vis spectrum clearly reveals the formation of silver nanoparticles. The size of the silver particles using TEM and XRD studies is found to be in the range 13-18 nm. These nanoparticles are found to be highly stable and even after prolonged storage for over 6 months they do not show significant aggregation. A plausible mechanism behind the formation of silver nanoparticles and their stabilization via capping has been investigated using FTIR and surface-enhanced resonance Raman spectroscopy

  11. A misleading false-negative result using Neisseria gonorrhoeae opa MGB multiplex PCR assay in patient's rectal sample due to partial mutations of the opa gene.

    Science.gov (United States)

    Vahidnia, Ali; van Empel, Pieter Jan; Costa, Sandra; Oud, Rob T N; van der Straaten, Tahar; Bliekendaal, Harry; Spaargaren, Joke

    2015-07-01

    A 53-year-old homosexual man presented at his general practitioner (GP) practice with a suspicion of sexually transmitted infection. Initial NAAT screening was performed for Chlamydia trachomatis and Neisseria gonorrhoeae. The patient was positive for Neisseria gonorrhoeae both for his urine and rectal sample. The subsequent confirmation test for Neisseria gonorrhoeae by a second laboratory was only confirmed for the urine sample and the rectal sample was negative. We report a case of a potential false-negative diagnosis of Neisseria gonorrhoeae due to mutations of DNA sequence in the probe region of opa-MGB assay of the rectal sample. The patient did not suffer any discomfort as diagnosis of Neisseria gonorrhoeae in his urine sample had already led to treatment by prescribing the patient with Ceftriaxone 500 mg IV dissolved in 1 ml lidocaine 2% and 4 mL saline. The patient also received a prescription for Azithromycin (2x500 mg).

  12. High temperature in combination with UV irradiation enhances horizontal transfer of stx2 gene from E. coli O157:H7 to non-pathogenic E. coli.

    Directory of Open Access Journals (Sweden)

    Wan-Fu Yue

    Full Text Available Shiga toxin (stx genes have been transferred to numerous bacteria, one of which is E. coli O157:H7. It is a common belief that stx gene is transferred by bacteriophages, because stx genes are located on lambdoid prophages in the E. coli O157:H7 genome. Both E. coli O157:H7 and non-pathogenic E. coli are highly enriched in cattle feedlots. We hypothesized that strong UV radiation in combination with high temperature accelerates stx gene transfer into non-pathogenic E. coli in feedlots.E. coli O157:H7 EDL933 strain were subjected to different UV irradiation (0 or 0.5 kJ/m(2 combination with different temperature (22, 28, 30, 32, and 37 °C treatments, and the activation of lambdoid prophages was analyzed by plaque forming unit while induction of Stx2 prophages was quantified by quantitative real-time PCR. Data showed that lambdoid prophages in E. coli O157:H7, including phages carrying stx2, were activated under UV radiation, a process enhanced by elevated temperature. Consistently, western blotting analysis indicated that the production of Shiga toxin 2 was also dramatically increased by UV irradiation and high temperature. In situ colony hybridization screening indicated that these activated Stx2 prophages were capable of converting laboratory strain of E. coli K12 into new Shiga toxigenic E. coli, which were further confirmed by PCR and ELISA analysis.These data implicate that high environmental temperature in combination with UV irradiation accelerates the spread of stx genes through enhancing Stx prophage induction and Stx phage mediated gene transfer. Cattle feedlot sludge are teemed with E. coli O157:H7 and non-pathogenic E. coli, and is frequently exposed to UV radiation via sunlight, which may contribute to the rapid spread of stx gene to non-pathogenic E. coli and diversity of shiga toxin producing E. coli.

  13. DNA microarray-based genome comparison of a pathogenic and a nonpathogenic strain of Xylella fastidiosa delineates genes important for bacterial virulence.

    Science.gov (United States)

    Koide, Tie; Zaini, Paulo A; Moreira, Leandro M; Vêncio, Ricardo Z N; Matsukuma, Adriana Y; Durham, Alan M; Teixeira, Diva C; El-Dorry, Hamza; Monteiro, Patrícia B; da Silva, Ana Claudia R; Verjovski-Almeida, Sergio; da Silva, Aline M; Gomes, Suely L

    2004-08-01

    Xylella fastidiosa is a phytopathogenic bacterium that causes serious diseases in a wide range of economically important crops. Despite extensive comparative analyses of genome sequences of Xylella pathogenic strains from different plant hosts, nonpathogenic strains have not been studied. In this report, we show that X. fastidiosa strain J1a12, associated with citrus variegated chlorosis (CVC), is nonpathogenic when injected into citrus and tobacco plants. Furthermore, a DNA microarray-based comparison of J1a12 with 9a5c, a CVC strain that is highly pathogenic and had its genome completely sequenced, revealed that 14 coding sequences of strain 9a5c are absent or highly divergent in strain J1a12. Among them, we found an arginase and a fimbrial adhesin precursor of type III pilus, which were confirmed to be absent in the nonpathogenic strain by PCR and DNA sequencing. The absence of arginase can be correlated to the inability of J1a12 to multiply in host plants. This enzyme has been recently shown to act as a bacterial survival mechanism by down-regulating host nitric oxide production. The lack of the adhesin precursor gene is in accordance with the less aggregated phenotype observed for J1a12 cells growing in vitro. Thus, the absence of both genes can be associated with the failure of the J1a12 strain to establish and spread in citrus and tobacco plants. These results provide the first detailed comparison between a nonpathogenic strain and a pathogenic strain of X. fastidiosa, constituting an important step towards understanding the molecular basis of the disease.

  14. Effect of nonpathogenic Escherichia coli monoassociation on small intestinal brush-border glycoconjugate moieties and cytokine production after colonization in ex-germ-free rats and pigs

    Czech Academy of Sciences Publication Activity Database

    Kolínská, Jiřina; Zákostelecká, Marie; Schwarzer, Martin; Štěpánková, Renata; Hudcovic, Tomáš; Kozáková, Hana

    2010-01-01

    Roč. 2, - (2010), s. 73-84 ISSN 1179-139X R&D Projects: GA MŠk(CZ) ME10017 Grant - others:GA AV ČR(CZ) IAA500200710; GA ČR(CZ) GA303/09/0449 Program:IA; GA Institutional research plan: CEZ:AV0Z50110509; CEZ:AV0Z50200510 Keywords : nonpathogenic E. coli * glycoconjugates * brush-border vesicles Subject RIV: CE - Biochemistry

  15. Modified Primers for the Identification of Nonpathogenic Fusarium oxysporum Isolates That Have Biological Control Potential against Fusarium Wilt of Cucumber in Taiwan

    Science.gov (United States)

    Wang, Chaojen; Lin, Yisheng; Lin, Yinghong; Chung, Wenhsin

    2013-01-01

    Previous investigations demonstrated that Fusarium oxysporum (Fo), which is not pathogenic to cucumbers, could serve as a biological control agent for managing Fusarium wilt of cucumber caused by Fo f. sp. cucumerinum (Foc) in Taiwan. However, thus far it has not been possible to separate the populations of pathogenic Fo from the nonpathogenic isolates that have biological control potential through their morphological characteristics. Although these two populations can be distinguished from one another using a bioassay, the work is laborious and time-consuming. In this study, a fragment of the intergenic spacer (IGS) region of ribosomal DNA from an Fo biological control agent, Fo366, was PCR-amplified with published general primers, FIGS11/FIGS12 and sequenced. A new primer, NPIGS-R, which was designed based on the IGS sequence, was paired with the FIGS11 primer. These primers were then evaluated for their specificity to amplify DNA from nonpathogenic Fo isolates that have biological control potential. The results showed that the modified primer pair, FIGS11/NPIGS-R, amplified a 500-bp DNA fragment from five of seven nonpathogenic Fo isolates. These five Fo isolates delayed symptom development of cucumber Fusarium wilt in greenhouse bioassay tests. Seventy-seven Fo isolates were obtained from the soil and plant tissues and then subjected to amplification using the modified primer pair; six samples showed positive amplification. These six isolates did not cause symptoms on cucumber seedlings when grown in peat moss infested with the isolates and delayed disease development when the same plants were subsequently inoculated with a virulent isolate of Foc. Therefore, the modified primer pair may prove useful for the identification of Fo isolates that are nonpathogenic to cucumber which can potentially act as biocontrol agents for Fusarium wilt of cucumber. PMID:23762289

  16. Resource capture and competitive ability of non-pathogenic Pseudogymnoascus spp. and P. destructans, the cause of white-nose syndrome in bats

    OpenAIRE

    Wilson, Michael B.; Held, Benjamin W.; Freiborg, Amanda H.; Blanchette, Robert A.; Salomon, Christine E.

    2017-01-01

    White-nose syndrome (WNS) is a devastating fungal disease that has been causing the mass mortality of hibernating bats in North America since 2006 and is caused by the psychrophilic dermatophyte Pseudogymnoascus destructans. Infected bats shed conidia into hibernaculum sediments and surfaces, but it is unknown if P. destructans can form stable, reproductive populations outside its bat hosts. Previous studies have found non-pathogenic Pseudogymnoascus in bat hibernacula, and these fungi may pr...

  17. FREKUENSI KUMAN Neisseriae gonorrhoeae YANG MENGINFEKSI WANITA USIA ANAK DI PADANG

    Directory of Open Access Journals (Sweden)

    Elizabeth Bahar

    2008-09-01

    Full Text Available AbstrakInfeksi traktus reproduksi wanita dapat disebabkan oleh penyakit hubungan seksual (sifilis, gonore, trikhomonas dan sebagainya. Dari semua penyakit kelamin insidens gonore merupakan yang tertinggi. Gonore penyakit yang disebabkan oleh kuman Neisseriae gonorrhoea atau disebut juga Coccus Gram negatif sampai saat ini merupakan suatu penyakit yang banyak menimbulkan problem bukan saja di negara berkembang, tetapi juga merupakan masalah di negara super power (adikuasa bahkan di seluruh dunia. Selain mempengaruhi kesehatan reproduksi erat sekali hubungannya dengan perilaku seks. Dari sudut psikologi sosial sebagian besar perilaku seks adalah perilaku sosial.Telah dilakukan penelitian dengan pengumpulan sampel secara cross sectional sampling dari wanita usia anak di Padang untuk mengetahui adanya kuman Neisseriae gonorrhoeae. Penelitian deskriptif dengan menggunakan metoda pewarnaan Gram mikroskopis langsung. Dari 18 sampel, ditemukan frekuensi penderita terinfeksi kuman Neisseriae gonorrhoeae 11 (61% dan 7 (38,9% non N gonorrhoeae. Dari variable-variable yang diuji anak sebagai sample yang terinfeksi kuman gonore berusia 1 – 3 tahun 4 (22,2 %, 4 – 7 tahun 6 (33,3%, 8 – 11 tahun 1 (5,5%} dan 12 – 15 tahun 0 (0%, di mana di lihat tingkat usia pendidikan anak pra sekolah dan sekolah. Orang tua si anak, ibu dan ayah pendidikan mencakup SD 0 (0%, SLP 0 (0%, SLA 14 (77,8 dan 7 (38,9% dan PT 4 (22,2% dan 10 (55,5 %. Kemudian pekerjaan orang tua anak meliputi RT 9 (50%, PNS/Swasta 8 (44,4% dan 14 (77,8%. Dagang 1 (5,6% dan 2 (11,1% dan sopir 2 (11,1%. Kesimpulannya penderita wanita usia anak di Padang cukup tinggi terinfeksi kuman N gonorrhoeae.Kata Kunci : gonore, wanita usia anak-anak, resistensi antibiotika.AbstractFemale genital infection may causes by sexual transmitted diseases (Syphilis, gonorrhoea, ect. From all vebereal diseases, incidence of gonorrhoeae is the highest. Current gonorrhoeae caused by Neisseriae gonorrhoeae or Gram

  18. The gonococcal genetic island and type IV secretion in the pathogenic Neisseria

    Directory of Open Access Journals (Sweden)

    Meghan E Ramsey

    2011-04-01

    Full Text Available Eighty percent of Neisseria gonorrhoeae strains and some Neisseria meningitidis strains encode a 57 kb gonococcal genetic island (GGI. The GGI was horizontally acquired and is inserted in the chromosome at the replication terminus. The GGI is flanked by direct repeats, and site-specific recombination at these sites results in excision of the GGI and may be responsible for its original acquisition. Although the role of the GGI in N. meningitidis is unclear, the GGI in N. gonorrhoeae encodes a type IV secretion system (T4SS. Type IV secretion systems are versatile multi-protein complexes and include both conjugation systems as well as effector systems that translocate either proteins or DNA-protein complexes. In N. gonorrhoeae, the T4SS secretes single-stranded chromosomal DNA into the extracellular milieu in a contact-independent manner. Importantly, the DNA secreted through the T4SS is effective in natural transformation and therefore contributes to the spread of genetic information through Neisseria populations. Mutagenesis experiments have identified genes for DNA secretion including those encoding putative structural components of the apparatus, peptidoglycanases which may act in assembly, and relaxosome components for processing the DNA and delivering it to the apparatus. The T4SS may also play a role in infection by N. gonorrhoeae. During intracellular infection, N. gonorrhoeae requires the Ton complex for iron acquisition and survival. However, N. gonorrhoeae strains that do not express the Ton complex can survive intracellularly if they express structural components of the T4SS. These data provide evidence that the T4SS is expressed during intracellular infection and suggest that the T4SS may provide an advantage for intracellular survival. Here we review our current understanding of how the GGI and type IV secretion affect natural transformation and pathogenesis in N. gonorrhoeae and N. meningitidis.

  19. Neisseria lactamica Causing a Lung Cavity and Skin Rash in a Renal Transplant Patient: First Report from India

    Directory of Open Access Journals (Sweden)

    Khalid Hamid Changal

    2016-01-01

    Full Text Available Neisseria lactamica, a commensal, has been very rarely reported to cause diseases in immunocompromised hosts. In medical literature, there is only one report of a cavitatory lung lesion caused by it. The patient was a kidney transplant recipient. Neisseria lactamica was found to be the cause of his pulmonary cavity and a desquamating rash on feet. With the rapidly spreading medical advance, more and more patients are getting organ transplants, so the population of immunocompromised people is on the rise. We expect more sinister and less expected organisms to cause diseases in patients who have organ transplants.

  20. A Neisseria meningitidis fbpABC mutant is incapable of using nonheme iron for growth.

    Science.gov (United States)

    Khun, H H; Kirby, S D; Lee, B C

    1998-05-01

    The neisserial fbpABC locus has been proposed to act as an iron-specific ABC transporter system. To confirm this assigned function, we constructed an fbpABC mutant in Neisseria meningitidis by insertional inactivation of fbpABC with a selectable antibiotic marker. The mutant was unable to use iron supplied from human transferrin, human lactoferrin, or iron chelates. However, the use of iron from heme and human hemoglobin was unimpaired. These results support the obligatory participation of fbpABC in neisserial periplasmic iron transport and do not indicate a role for this genetic locus in the heme iron pathway.

  1. fbpABC gene cluster in Neisseria meningitidis is transcribed as an operon.

    Science.gov (United States)

    Khun, H H; Deved, V; Wong, H; Lee, B C

    2000-12-01

    The neisserial fbpABC locus has been proposed to constitute a single transcriptional unit. To confirm this operonic arrangement, transcription assays using reverse transcriptase PCR amplification were conducted with Neisseria meningitidis. The presence of fbpAB and fbpBC transcripts obtained by priming cDNA synthesis with an fbpC-sequence-specific oligonucleotide indicates that fbpABC is organized as a single expression unit. The ratio of fbpA to fbpABC mRNA was approximately between 10- to 20-fold, as determined by real-time quantitative PCR.

  2. Neisseria meningitidis: a neglected cause of infectious haemorrhagic fever in the amazon rainforest.

    Science.gov (United States)

    Barroso, David E; Silva, Luciete A

    2007-12-01

    Neisseria meningitidis has not been seen as a significant cause of infectious haemorrhagic fever in the Amazon inlands; most reported cases are from the city of Manaus, the capital of the State of Amazonas. This picture is sustained by the lack of reliable microbiology laboratories, the perception of the health care workers, and the difficult to reach medical assistance; thus the number of confirmed cases is even lower with no reference of the strains phenotype. We report here the investigation of a case of suspected meningococcemia and his close contacts in a rural community in the Coari Lake, up the Amazon River.

  3. Neisseria meningitidis: a neglected cause of infectious haemorrhagic fever in the amazon rainforest

    Directory of Open Access Journals (Sweden)

    David E. Barroso

    Full Text Available Neisseria meningitidis has not been seen as a significant cause of infectious haemorrhagic fever in the Amazon inlands; most reported cases are from the city of Manaus, the capital of the State of Amazonas. This picture is sustained by the lack of reliable microbiology laboratories, the perception of the health care workers, and the difficult to reach medical assistance; thus the number of confirmed cases is even lower with no reference of the strains phenotype. We report here the investigation of a case of suspected meningococcemia and his close contacts in a rural community in the Coari Lake, up the Amazon River.

  4. Clinical evaluation of a loop-mediated isothermal amplification (LAMP) assay for rapid detection of Neisseria meningitidis in cerebrospinal fluid.

    Science.gov (United States)

    Lee, DoKyung; Kim, Eun Jin; Kilgore, Paul E; Kim, Soon Ae; Takahashi, Hideyuki; Ohnishi, Makoto; Anh, Dang Duc; Dong, Bai Qing; Kim, Jung Soo; Tomono, Jun; Miyamoto, Shigehiko; Notomi, Tsugunori; Kim, Dong Wook; Seki, Mitsuko

    2015-01-01

    Neisseria meningitidis (Nm) is a leading causative agent of bacterial meningitis in humans. Traditionally, meningococcal meningitis has been diagnosed by bacterial culture. However, isolation of bacteria from patients' cerebrospinal fluid (CSF) is time consuming and sometimes yields negative results. Recently, polymerase chain reaction (PCR)-based diagnostic methods of detecting Nm have been considered the gold standard because of their superior sensitivity and specificity compared with culture. In this study, we developed a loop-mediated isothermal amplification (LAMP) method and evaluated its ability to detect Nm in cerebrospinal fluid (CSF). We developed a meningococcal LAMP assay (Nm LAMP) that targets the ctrA gene. The primer specificity was validated using 16 strains of N. meningitidis (serogroup A, B, C, D, 29-E, W-135, X, Y, and Z) and 19 non-N. meningitidis species. Within 60 min, the Nm LAMP detected down to ten copies per reaction with sensitivity 1000-fold more than that of conventional PCR. The LAMP assays were evaluated using a set of 1574 randomly selected CSF specimens from children with suspected meningitis collected between 1998 and 2002 in Vietnam, China, and Korea. The LAMP method was shown to be more sensitive than PCR methods for CSF samples (31 CSF samples were positive by LAMP vs. 25 by PCR). The detection rate of the LAMP method was substantially higher than that of the PCR method. In a comparative analysis of the PCR and LAMP assays, the clinical sensitivity, specificity, positive predictive value, and negative predictive value of the LAMP assay were 100%, 99.6%, 80.6%, and 100%, respectively. Compared to PCR, LAMP detected Nm with higher analytical and clinical sensitivity. This sensitive and specific LAMP method offers significant advantages for screening patients on a population basis and for diagnosis in clinical settings.

  5. Clinical evaluation of a loop-mediated isothermal amplification (LAMP assay for rapid detection of Neisseria meningitidis in cerebrospinal fluid.

    Directory of Open Access Journals (Sweden)

    DoKyung Lee

    Full Text Available Neisseria meningitidis (Nm is a leading causative agent of bacterial meningitis in humans. Traditionally, meningococcal meningitis has been diagnosed by bacterial culture. However, isolation of bacteria from patients' cerebrospinal fluid (CSF is time consuming and sometimes yields negative results. Recently, polymerase chain reaction (PCR-based diagnostic methods of detecting Nm have been considered the gold standard because of their superior sensitivity and specificity compared with culture. In this study, we developed a loop-mediated isothermal amplification (LAMP method and evaluated its ability to detect Nm in cerebrospinal fluid (CSF.We developed a meningococcal LAMP assay (Nm LAMP that targets the ctrA gene. The primer specificity was validated using 16 strains of N. meningitidis (serogroup A, B, C, D, 29-E, W-135, X, Y, and Z and 19 non-N. meningitidis species. Within 60 min, the Nm LAMP detected down to ten copies per reaction with sensitivity 1000-fold more than that of conventional PCR. The LAMP assays were evaluated using a set of 1574 randomly selected CSF specimens from children with suspected meningitis collected between 1998 and 2002 in Vietnam, China, and Korea. The LAMP method was shown to be more sensitive than PCR methods for CSF samples (31 CSF samples were positive by LAMP vs. 25 by PCR. The detection rate of the LAMP method was substantially higher than that of the PCR method. In a comparative analysis of the PCR and LAMP assays, the clinical sensitivity, specificity, positive predictive value, and negative predictive value of the LAMP assay were 100%, 99.6%, 80.6%, and 100%, respectively.Compared to PCR, LAMP detected Nm with higher analytical and clinical sensitivity. This sensitive and specific LAMP method offers significant advantages for screening patients on a population basis and for diagnosis in clinical settings.

  6. Distribution and prevalence of the Australian non-pathogenic rabbit calicivirus is correlated with rainfall and temperature.

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    June Liu

    Full Text Available BACKGROUND: Australia relies heavily on rabbit haemorrhagic disease virus (RHDV for the biological control of introduced European wild rabbits Oryctolagus cuniculus, which are significant economic and environmental pests. An endemic non-pathogenic rabbit calicivirus termed RCV-A1 also occurs in wild rabbits in Australian and provides partial protection against lethal RHDV infection, thus interfering with effective rabbit control. Despite its obvious importance for rabbit population management, little is known about the epidemiology of this benign rabbit calicivirus. METHODS: We determined the continent-wide distribution and prevalence of RCV-A1 by analysing 1,805 serum samples from wild rabbit populations at 78 sites across Australia for the presence of antibodies to RCV-A1 using a serological test that specifically detects RCV-A1 antibodies and does not cross-react with co-occurring RHDV antibodies. We also investigated possible correlation between climate variables and prevalence of RCV-A1 by using generalised linear mixed effect models. RESULTS: Antibodies to RCV-A1 were predominantly detected in rabbit populations in cool, high rainfall areas of the south-east and south-west of the continent. There was strong support for modelling RCV-A1 prevalence as a function of average annual rainfall and minimum temperature. The best ranked model explained 26% of the model structural deviance. According to this model, distribution and prevalence of RCV-A1 is positively correlated with periods of above average rainfall and negatively correlated with periods of drought. IMPLICATIONS: Our statistical model of RCV-A1 prevalence will greatly increase our understanding of RCV-A1 epidemiology and its interaction with RHDV in Australia. By defining the environmental conditions associated with the prevalence of RCV-A1, it also contributes towards understanding the distribution of similar viruses in New Zealand and Europe.

  7. The sugarcane defense protein SUGARWIN2 causes cell death in Colletotrichum falcatum but not in non-pathogenic fungi.

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    Flávia P Franco

    Full Text Available Plants respond to pathogens and insect attacks by inducing and accumulating a large set of defense-related proteins. Two homologues of a barley wound-inducible protein (BARWIN have been characterized in sugarcane, SUGARWIN1 and SUGARWIN2 (sugarcane wound-inducible proteins. Induction of SUGARWINs occurs in response to Diatraea saccharalis damage but not to pathogen infection. In addition, the protein itself does not show any effect on insect development; instead, it has antimicrobial activities toward Fusarium verticillioides, an opportunistic fungus that usually occurs after D. saccharalis borer attacks on sugarcane. In this study, we sought to evaluate the specificity of SUGARWIN2 to better understand its mechanism of action against phytopathogens and the associations between fungi and insects that affect plants. We used Colletotrichum falcatum, a fungus that causes red rot disease in sugarcane fields infested by D. saccharalis, and Ceratocystis paradoxa, which causes pineapple disease in sugarcane. We also tested whether SUGARWIN2 is able to cause cell death in Aspergillus nidulans, a fungus that does not infect sugarcane, and in the model yeast Saccharomyces cerevisiae, which is used for bioethanol production. Recombinant SUGARWIN2 altered C. falcatum morphology by increasing vacuolization, points of fractures and a leak of intracellular material, leading to germling apoptosis. In C. paradoxa, SUGARWIN2 showed increased vacuolization in hyphae but did not kill the fungi. Neither the non-pathogenic fungus A. nidulans nor the yeast S. cerevisiae was affected by recombinant SUGARWIN2, suggesting that the protein is specific to sugarcane opportunistic fungal pathogens.

  8. Refolding, purification and crystallization of the FrpB outer membrane iron transporter from Neisseria meningitidis

    International Nuclear Information System (INIS)

    Saleem, Muhammad; Prince, Stephen M.; Patel, Hema; Chan, Hannah; Feavers, Ian M.; Derrick, Jeremy P.

    2012-01-01

    The refolding, purification and crystallization of FrpB from the meningitis pathogen Neisseria meningitidis is described. FrpB is an integral outer membrane protein from the human pathogen Neisseria meningitidis. It is a member of the TonB-dependent transporter family and promotes the uptake of iron across the outer membrane. There is also evidence that FrpB is an antigen and hence a potential component of a vaccine against meningococcal meningitis. FrpB incorporating a polyhistidine tag was overexpressed in Escherichia coli into inclusion bodies. The protein was then solubilized in urea, refolded and purified to homogeneity. Two separate antigenic variants of FrpB were crystallized by sitting-drop vapour diffusion. Crystals of the F5-1 variant diffracted to 2.4 Å resolution and belonged to space group C2, with unit-cell parameters a = 176.5, b = 79.4, c = 75.9 Å, β = 98.3°. Crystal-packing calculations suggested the presence of a monomer in the asymmetric unit. Crystals of the F3-3 variant also diffracted to 2.4 Å resolution and belonged to space group P2 1 2 1 2 1 , with unit-cell parameters a = 85.3, b = 104.6, c = 269.1 Å. Preliminary analysis suggested the presence of an FrpB trimer in the asymmetric unit

  9. Molecular biology of Neisseria meningitidis class 5 and H. 8 outer membrane proteins

    Energy Technology Data Exchange (ETDEWEB)

    Kawula, T.H.

    1987-01-01

    One of the surface structures responsible for inter- and intrastrain antigenic variability in meningococci is the heat-modifiable class 5 (C.5) protein. Neisseria meningitidis strain FAM18 (a meningococcal disease isolate) expressed two different C.5 proteins (C.5a and C.5b) identifiable by sodium dodecyl sulfate polyacrylamide gel electrophoresis. We generated two monoclonal antibodies (MAbs), each specific for one of the identified C.5 proteins. The MAbs, which were bactericidal for variants expressing the appropriate C.5 protein, were used to study C.5 expression changes in FAM18. The H.8 protein is an antigenically conserved outer membrane protein expressed almost exclusively by the pathogenic Neisseria. We have cloned and sequenced an H.8 gene from N. meningitidis FAM18. The predicted H.8 amino acid sequence indicated that the most probable signal peptide processing site matched the consensus prokaryotic lipoprotein processing/modification sequence. We then showed that the H.8 protein could be labeled with {sup 14}C-palmitic acid, confirming that H.8 was a lipoprotein. Processing of the H.8 protein was inhibited by globomycin in E. coli indicating that H.8 was modified by the described lipoprotein processing/modifying pathway described in both gram negative and gram positive genera.

  10. Molecular detection and confirmation of Neisseria gonorrhoeae in urogenital and extragenital specimens using the Abbott CT/NG RealTime assay and an in-house assay targeting the porA pseudogene.

    LENUS (Irish Health Repository)

    Walsh, A

    2011-04-01

    Culture for detection of Neisseria gonorrhoeae (NG) is being replaced by molecular assays, but difficulties are observed with false positive and negatives results, especially for extragenital samples. This study evaluates the Abbott CT\\/NG Real-Time assay and a real-time porA pseudogene assay. Samples (n = 600) from a mixed prevalence Irish population include 164 male urines with corresponding urethral swabs, 58 endocervical swabs, 173 male pharyngeal swabs, 205 male rectal swabs, 36 NG clinical isolates and 26 commensal Neisseria species isolates. There was a 100% concordance between the Abbott CT\\/NG Real-Time and the porA assay. The positivity rate was 1.2%, 1.7%, 8.1% and 5.8% for FVU\\/urethral swabs, endocervical, pharyngeal and rectal swabs, respectively. These results were compared to culture and discrepancies were found with nine pharyngeal and three rectal swabs. Seven of the 12 discrepant positive samples were sequenced and were confirmed "true positives". The sensitivity and specificity of the molecular assays was 100%. The sensitivity of the culture-based testing was 100% for urogenital samples but 36% and 75% for pharyngeal and rectal swabs, respectively. The combined Abbott CT\\/NG and porA assays provide a valuable alternative to culture and also generate a significant increase in the diagnosis of pharyngeal and rectal NG infection.

  11. Comparison of Neisseria gonorrhoeae MICs Obtained by Etest and Agar Dilution for Ceftriaxone, Cefpodoxime, Cefixime and Azithromycin.

    Science.gov (United States)

    Gose, Severin; Kong, Carol J; Lee, Yer; Samuel, Michael C; Bauer, Heidi M; Dixon, Paula; Soge, Olusegun O; Lei, John; Pandori, Mark

    2013-10-24

    We evaluated Neisseria gonorrhoeae Etest minimum inhibitory concentrations (MICs) relative to agar dilution MICs for 664 urethral isolates for ceftriaxone (CRO) and azithromycin (AZM), 351 isolates for cefpodoxime (CPD) and 315 isolates for cefixime (CFM). Etest accurately determined CPD, CFM and AZM MICs, but resulted in higher CRO MICs. © 2013. Published by Elsevier B.V. All rights reserved.

  12. NMR assignment of intrinsically disordered self-processing module of the FrpC protein of Neisseria meningitidis

    Czech Academy of Sciences Publication Activity Database

    Kubáň, V.; Nováček, J.; Bumba, Ladislav; Žídek, L.

    2015-01-01

    Roč. 9, č. 2 (2015), s. 435-440 ISSN 1874-2718 R&D Projects: GA ČR(CZ) GAP207/11/0717 Institutional support: RVO:61388971 Keywords : FrpC * Self-processing module * Neisseria meningitidis Subject RIV: EE - Microbiology, Virology Impact factor: 0.687, year: 2015

  13. Draft Genome Sequence of Neisseria gonorrhoeae Strain NG_869 with Penicillin, Tetracycline and Ciprofloxacin Resistance Determinants Isolated from Malaysia

    OpenAIRE

    Ang, Geik Yong; Yu, Choo Yee; Yong, Delicia Ann; Cheong, Yuet Meng; Yin, Wai-Fong; Chan, Kok-Gan

    2016-01-01

    Gonorrhea is a sexually transmitted infection caused by Neisseria gonorrhoeae and the increasing reports of multidrug-resistant gonococcal isolates are a global public health care concern. Herein, we report the genome sequence of N. gonorrhoeae strain NG_869 isolated from Malaysia which may provide insights into the drug resistance determinants in gonococcal bacteria.

  14. Deletion of porA by recombination between clusters of repetitive extragenic palindromic sequences in Neisseria meningitidis

    NARCIS (Netherlands)

    van der Ende, A.; Hopman, C. T.; Dankert, J.

    1999-01-01

    PorA is an important component in a vaccine against infection with Neisseria meningitidis. However, porA-negative meningococci were isolated from patients, thereby potentially limiting the role of PorA-mediated immunity. To analyze the mechanism by which the porA deletion occurred, the regions

  15. Representational difference analysis of Neisseria meningitidis identifies sequences that are specific for the hyper-virulent lineage III clone

    NARCIS (Netherlands)

    Bart, A.; Dankert, J.; van der Ende, A.

    2000-01-01

    Neisseria meningitidis may cause meningitis and septicemia. Since the early 1980s, an increased incidence of meningococcal disease has been caused by the lineage III clone in many countries in Europe and in New Zealand. We hypothesized that lineage III meningococci have specific DNA sequences,

  16. NmeSI restriction-modification system identified by representational difference analysis of a hypervirulent Neisseria meningitidis strain

    NARCIS (Netherlands)

    Bart, A.; Pannekoek, Y.; Dankert, J.; van der Ende, A.

    2001-01-01

    Neisseria meningitidis is a gram-negative bacterium that may cause meningitis, sepsis, or both. The increase in the incidence of meningococcal disease in various countries in the past 2 decades is mainly due the genotypically related lineage III meningococci. The chromosomal DNA differences between

  17. Phenotypic and genotypic changes in a new clone complex of Neisseria meningitidis causing disease in The Netherlands, 1958-1990

    NARCIS (Netherlands)

    Scholten, R. J.; Poolman, J. T.; Valkenburg, H. A.; Bijlmer, H. A.; Dankert, J.; Caugant, D. A.

    1994-01-01

    To characterize the phenotypic and genotypic changes that occurred in a new clone lineage of Neisseria meningitidis (lineage III) in the Netherlands, the electrophoretic type (ET) was determined for 79 serogroup B isolates of serotype 4 or subtype P1.4 (or both) obtained between 1958 and 1990 from

  18. Self-esteem in children and adolescents after septic shock caused by Neisseria meningitidis: scars do matter

    NARCIS (Netherlands)

    Vermunt, Lindy C.; Buysse, Corinne M.; Joosten, Koen F.; Oranje, Arnold P.; Hazelzet, Jan A.; Verhulst, Frank C.; Utens, Elisabeth M.

    2008-01-01

    To investigate self-esteem and its relation to scars, amputations, and orthopedic sequelae in children and adolescents long term after meningococcal septic shock (MSS) caused by Neisseria meningitidis. The Dutch versions of the Self-Perception Profile for Children (SPP-C; 8-11 years) and the

  19. Asymtomatic carriage of Neisseria meningitidis and Neisseria lactamica in relation to Streptococcus pneumoniae and Haemophilus influenzae colonization in healthy children: Apropos of 1400 children sampled

    International Nuclear Information System (INIS)

    Bakir, Mustafa; Yagci, Aysegul; Ulger, Nurver; Akbenlioglu, Cengiz; Ilki, Arzu; Soyletir, Guner

    2001-01-01

    Meningococcal disease is one of the most important causes of morbidity and mortality among children in many parts of the world. Main reservoir of carriage and site of meningococcal dissemination appears to be the upper respiratory tract. Colonization of Neisseria meningitidis and lactamica and factors affecting this carriage were determined in a group of healthy children aged 0-10 years. Meningococcus and N. lactamica carriage were detected in 17 (1.23%) and 245 (17.7%) of 1382 subjects, respectively. Number (%) of serogroups for meningococci was 1 (6), 5 (29), 0 (0), 1 (6), 1 (6), and 9 (53) for A, B, C, D, W135, and Y, respectively. Having more than three household members, elementary school attendance, pharyngeal carriage of Streptococcus pneumoniae and Haemophilus influenzae were associated with carriage of meningococci, whereas age less than 24-month was associated with carriage of N. lactamica. There was a reverse carriage rate between N. meningitidis and N. lactamica by age which may suggest a possible protective role of N. lactamica against meningococcal colonization among pre-school children

  20. Gonorrhea in Indonesia: High Prevalence of Asymptomatic Urogenital Gonorrhea but No Circulating Extended Spectrum Cephalosporins-Resistant Neisseria gonorrhoeae Strains in Jakarta, Yogyakarta, and Denpasar, Indonesia

    NARCIS (Netherlands)

    Hananta, I. Putu Yuda; van Dam, Alje P.; Bruisten, Sylvia Maria; Schim van der Loeff, Maarten Franciscus; Soebono, Hardyanto; de Vries, Henry John Christiaan

    2016-01-01

    Little is known about the epidemiology of asymptomatic urogenital gonorrhea and antimicrobial susceptibility of Neisseria gonorrhoeae (NG) strains circulating in Indonesia. We studied these issues in 3 large Indonesian cities. In 2014, participants were recruited from sexually transmitted infection

  1. Risk factors for antimicrobial-resistant Neisseria gonorrhoeae and characteristics of patients infected with gonorrhea.

    Science.gov (United States)

    Fuertes de Vega, Irene; Baliu-Piqué, Carola; Bosch Mestres, Jordi; Vergara Gómez, Andrea; Vallés, Xavier; Alsina Gibert, Mercè

    2018-03-01

    There are very few data available regarding risk factors associated with antibiotic resistant-Neisseria gonorrhoeae. A study was conducted on 110 samples from 101 patients with gonococcal infection, in order to describe their characteristics and compare them with the antimicrobial susceptibility profile of their samples. An association was observed between resistant infections and heterosexual men, older age, concurrent sexually transmitted infection, and unsafe sexual behaviors. There is a need for improved data on the risk factors associated with antibiotic resistant gonococcal infection in order to identify risk groups, and to propose public health strategies to control this infection. Copyright © 2016 Elsevier España, S.L.U. and Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.

  2. Identification of Novel Immunogenic Proteins of Neisseria gonorrhoeae by Phage Display.

    Directory of Open Access Journals (Sweden)

    Daniel O Connor

    Full Text Available Neisseria gonorrhoeae is one of the most prevalent sexually transmitted diseases worldwide with more than 100 million new infections per year. A lack of intense research over the last decades and increasing resistances to the recommended antibiotics call for a better understanding of gonococcal infection, fast diagnostics and therapeutic measures against N. gonorrhoeae. Therefore, the aim of this work was to identify novel immunogenic proteins as a first step to advance those unresolved problems. For the identification of immunogenic proteins, pHORF oligopeptide phage display libraries of the entire N. gonorrhoeae genome were constructed. Several immunogenic oligopeptides were identified using polyclonal rabbit antibodies against N. gonorrhoeae. Corresponding full-length proteins of the identified oligopeptides were expressed and their immunogenic character was verified by ELISA. The immunogenic character of six proteins was identified for the first time. Additional 13 proteins were verified as immunogenic proteins in N. gonorrhoeae.

  3. Crystal structure of the Neisseria gonorrhoeae MtrD inner membrane multidrug efflux pump.

    Directory of Open Access Journals (Sweden)

    Jani Reddy Bolla

    Full Text Available Neisseria gonorrhoeae is an obligate human pathogen and the causative agent of the sexually-transmitted disease gonorrhea. The control of this disease has been compromised by the increasing proportion of infections due to antibiotic-resistant strains, which are growing at an alarming rate. The MtrCDE tripartite multidrug efflux pump, belonging to the hydrophobic and amphiphilic efflux resistance-nodulation-cell division (HAE-RND family, spans both the inner and outer membranes of N. gonorrhoeae and confers resistance to a variety of antibiotics and toxic compounds. We here report the crystal structure of the inner membrane MtrD multidrug efflux pump, which reveals a novel structural feature that is not found in other RND efflux pumps.

  4. Immunogenicity of recombinant class 1 protein from Neisseria meningitidis refolded into phospholipid vesicles and detergent.

    Science.gov (United States)

    Niebla, O; Alvarez, A; Martín, A; Rodríguez, A; Delgado, M; Falcón, V; Guillén, G

    2001-05-14

    The possibility of eliciting bactericidal antibodies against a recombinant class 1 protein (P1) from Neisseria meningitidis, joined to the first 45 amino acids of the neisserial LpdA protein (PM82), was examined. P1 was produced in Escherichia coli as intracellular inclusion bodies, from which it was purified and reconstituted by (a) inclusion into phospholipid vesicles and detergent and (b) refolding in 0.1% SDS. When Balb/c mice were immunised, high titres of subtype-specific bactericidal antibodies against P1 were obtained in both cases. These results suggest that in spite of being a denaturing agent, it is possible to use SDS to reconstitute the P1 protein in a conformation that exposes the immunodominat regions.

  5. Pneumonia caused by Neisseria meningitidis: report of a case and review of the literature

    International Nuclear Information System (INIS)

    Acosta M, Rafael E; Rada E, Robin A

    2010-01-01

    Pneumonia caused by Neisseria meningitidis, a gram-negative diplococcus affecting only humans, is a rare disease that was first recognized more than 60 years ago. The infection is usually manifested as meningitis and septicemia with cutaneous manifestations. Involvement of the lower respiratory tract is much less frequently diagnosed, partly because this microorganism can be present in the oropharyngeal flora of up to 10% of asymptomatic people. The serotypes most frequently involved in lung infections are: B, Y, and W-135. Serotype Y has been held to be most important. In cases of pneumonia, diagnosis has to be reached by isolation of the microorganism in blood and/or pleural fluid. Mortality is low, and person-to-person transmission, although documented, is rare. Complications such as pulmonary abscess, pleural effusion, and pericarditis are infrequent.

  6. Neisseria meningitidis expressing lgtB lipopolysaccharide targets DC-SIGN and modulates dendritic cell function.

    Science.gov (United States)

    Steeghs, Liana; van Vliet, Sandra J; Uronen-Hansson, Heli; van Mourik, Andries; Engering, Anneke; Sanchez-Hernandez, Martha; Klein, Nigel; Callard, Robin; van Putten, Jos P M; van der Ley, Peter; van Kooyk, Yvette; van de Winkel, Jan G J

    2006-02-01

    Neisseria meningitidis lipopolysaccharide (LPS) has been identified as a major determinant of dendritic cell (DC) function. Here we report that one of a series of meningococcal mutants with defined truncations in the lacto-N-neotetraose outer core of the LPS exhibited unique strong adhesion and internalization properties towards DC. These properties were mediated by interaction of the GlcNAc(beta1-3)-Gal(beta1-4)-Glc-R oligosaccharide outer core of lgtB LPS with the dendritic-cell-specific ICAM-3 grabbing non-integrin (DC-SIGN) lectin receptor. Activation of DC-SIGN with this novel oligosaccharide ligand skewed T-cell responses driven by DC towards T helper type 1 activity. Thus, the use of lgtB LPS may provide a powerful instrument to selectively induce the desired arm of the immune response and potentially increase vaccine efficacy.

  7. Intercontinental spread of a genetically distinctive complex of clones of Neisseria meningitidis causing epidemic disease.

    Science.gov (United States)

    Caugant, D A; Frøholm, L O; Bøvre, K; Holten, E; Frasch, C E; Mocca, L F; Zollinger, W D; Selander, R K

    1986-07-01

    Strains of Neisseria meningitidis responsible for an epidemic of meningococcal disease occurring in Norway since the mid-1970s and for recent increases in the incidence of disease in several other parts of Europe have been identified by multilocus enzyme electrophoresis as members of a distinctive group of 22 closely related clones (the ET-5 complex). Clones of this complex have also colonized South Africa, Chile, Cuba, and Florida, where they have been identified as the causative agents of recent outbreaks of meningococcal disease. There is strong circumstantial evidence that outbreaks of disease occurring in Miami in 1981 and 1982 were caused in large part by bacteria that reached Florida via human immigrants from Cuba.

  8. SIGNIFICATIVE ANO PROBLEM BASED LEARNING IN IMMUNOLOGY: OBTAINING A KIT TO TYPE NEISSERIA GONORRHOEAE

    Directory of Open Access Journals (Sweden)

    Marina Miguez

    2003-06-01

    Full Text Available Neisseria gonorrhoeae (Ng have been classified serologically on the basis of the antigenicity of the major porin (Por. Por! occurs in two immunochemically distinct serogroups: PorlA and Porffi. Because the diagnostic, therapeutic, social, and legal corisequences of misidentification of a nongonococcal Neisseria isolate as Ng can be substantial, the accurate and rapid identification of this organism is important. Typifying of Ng is done by techniques baséd on phenotypic characteristics and plasmidic content that individually don't reach an adequate discrimination, and so combination of techniques ·must be used. The aim of this work is to obtain polyclonal specificAb that discriminate Ng types Por!Aand Porffi. For this purpose, weimmunized two rabbits with sonicated PorlA and Porm strains ofNg (isolated from clínica! samples and serologically classified. The Ab response was analyzed along the protocol by ELISAand by direct agglutination with latex coated with sonicated Ng. With these data, we selected the bleeding providing the serum with maximum specific Ab ti ter to prepare the typing reagents. Unwanted Ab directed against shared epitopes were removed by adsorption with Ng latex. The typing reagents were obtained by coating latex with each depleted sera. Our results suggest that high titers of specific Ab be obtained for both strains ofNg and the depleted sera be discriminated between both strains. These results suggest that these diagnostic reagents could be useful to confirrn presumptive identification by a simple and rapid method.

  9. A non-pathogenic live vector as an efficient delivery system in vaccine design for the prevention of HPV16 E7-overexpressing cancers.

    Science.gov (United States)

    Hosseinzadeh, Sahar; Bolhassani, Azam; Rafati, Sima; Taheri, Tahereh; Zahedifard, Farnaz; Daemi, Amin; Taslimi, Yasaman; Hashemi, Mehrdad; Memarnejadian, Arash

    2013-01-01

    The attenuated or non-pathogenic live vectors have been evolved specifically to deliver DNA into cells as efficient delivery tools in gene therapy. Recently, a non-pathogenic protozoan, Leishmania tarentolae (L.tar) has attracted a great attention. In current study, we used Leishmania expression system (LEXSY) for stable expression of HPV16 E7 linked to different mini-chaperones [N-/C-terminal of gp96] and compared their immunogenicity and protective effects in C57BL/6 mice against TC-1 challenge. TC-1 murine model is primary C57BL/6 mice lung epithelial cells co-transformed with HPV16 E6, HPV16 E7 and ras oncogenes. Our results showed that subcutaneous administration of mice with both the recombinant L.tar-E7-NT (gp96) and L.tar-E7-CT (gp96) led to enhance the levels of IFN-γ and also IgG2a before and after challenge with TC-1. Furthermore, L.tar-E7-CT (gp96) live vaccine indicated significant protective effects as compared to control groups as well as group vaccinated with L.tar-E7. Indeed, the recombinant live vector is capable of eliciting effective humoral and cellular immune responses in mice, but however, further studies are required to increase their efficacy.

  10. A comparison of the endotoxin biosynthesis and protein oxidation pathways in the biogenesis of the outer membrane of Escherichia coli and Neisseria meningitidis

    Directory of Open Access Journals (Sweden)

    Susannah ePiek

    2012-12-01

    Full Text Available The Gram-negative bacterial cell envelope consists of an inner membrane (IM that surrounds the cytoplasm, and an asymmetrical outer-membrane (OM that forms a protective barrier to the external environment. The OM consists of lipopolysaccahride (LPS, phospholipids, outer membrane proteins (OMPs and lipoproteins. Oxidative protein folding mediated by periplasmic oxidoreductases is required for the correct biogenesis of the protein components, mainly constituents of virulence determinants such as pili, flagella and toxins, of the Gram-negative OM. Recently, periplasmic oxidoreductases have been implicated in LPS biogenesis of Escherichia coli and Neisseria meningitidis. Differences in OM biogenesis, in particular the transport pathways for endotoxin to the OM, the composition and role of the protein oxidation and isomerisation pathways and the regulatory networks that control them have been found in these two Gram-negative species suggesting that although form and function of the OM is conserved, these conserved pathways have been modified to suit the lifestyle of each organism.

  11. Detección de cepas de Neisseria meningitidis resistentes a rifampicina en el Uruguay Detection of rifampicin-resistant strains of Neisseria meningitidis in Uruguay

    Directory of Open Access Journals (Sweden)

    Gabriel Pérez Giffoni

    2011-12-01

    Full Text Available El objetivo de este trabajo fue caracterizar fenotípica y genotípicamente dos aislamientos de Neisseria meningitidis resistentes a rifampicina relacionados con dos eventos independientes de transmisión de enfermedad meningocócica grave que se presentaron en septiembre y octubre de 2010 en Montevideo, Uruguay. Se revisó también la base de datos de la vigilancia nacional de resistencia a los antimicrobianos de los últimos 10 años, para estimar la frecuencia de la particularidad de los meningococos caracterizados. La resistencia a rifampicina se estudió por el método epsilométrico. El serotipo y serosubtipo de los aislamientos se determinaron por ELISA y la caracterización genotípica se realizó por digestión del ADN con NheI y electroforesis en gel con campo pulsátil. Ambos aislamientos eran idénticos, B:2a:P1.5, y su fenotipo no figuraba en la colección de 408 cepas de N. meningitidis aisladas en el Uruguay en los últimos 10 años, con la excepción de dos aislamientos sensibles a rifampicina. Los dos aislamientos estudiados también compartían un pulsotipo único, diferente del de otros dos aislamientos resistentes a rifampicina obtenidos en 2003 y 2007. Por lo tanto, ambos eventos de transmisión fueron causados por una única cepa resistente a rifampicina, que podría haberse introducido al país desde otras regiones o haberse originado por un cambio del serogrupo C al B, como producto de la presión selectiva ejercida por vacunas administradas a la población. Es necesario mantener y extremar la vigilancia. No obstante, en vista de que hasta el momento este tipo de hallazgo ha sido esporádico, no se justifica cambiar el fármaco antimicrobiano que se administra a los contactos para la profilaxis, a menos que se identifique un caso secundario.The objective of this study was to characterize the phenotype and genotype of two isolates of rifampicin-resistant Neisseria meningitidis associated with two independent events

  12. A misleading urethral smear with polymorphonuclear leucocytes and intracellular diplococci; case report of urethritis caused by Neisseria meningitidis.

    Science.gov (United States)

    Genders, R E; Spitaels, D; Jansen, C L; van den Akker, Th W; Quint, K D

    2013-12-01

    The primary pathogens found in men with urethritis are Chlamydia trachomatis and Neisseria gonorrhoeae. Rapid diagnosis of N. gonorrhoeae infection can be made based on a Gram- or methylene blue-stained urethral smear. We describe a case of a man with purulent penile discharge, in which microscopic examination led to the presumptive diagnosis of gonorrhoea. A nucleic acid amplification test was negative for N. gonorrhoeae but positive for C. trachomatis. Culture showed Gram-negative diplococci which were identified as Neisseria meningitidis. N. meningitidis can be sporadically pathogenic in the genito-urinary tract and mimicks gonococcal urethritis, and appears identical by microscopy. When a gonococcal urethritis is suspected based on clinical signs and microscopic examination, but investigatory tests cannot confirm the diagnosis, a N. meningitidis infection should be considered.

  13. In Vitro Susceptibility of Neisseria gonorrhoeae Strains to Mupirocin, an Antibiotic Reformulated for Parenteral Administration in Nanoliposomes.

    Science.gov (United States)

    Cern, Ahuva; Connolly, Kristie L; Jerse, Ann E; Barenholz, Yechezkel

    2018-04-01

    Neisseria gonorrhoeae is an urgent antibiotic-resistant threat. This study determined the MICs of mupirocin to be 0.0039 to 0.0625 μg/ml for 94 N. gonorrhoeae strains. Cross-resistance with other antibiotics was not detected. Mupirocin, which is currently limited to topical administration, demonstrated activity by injection when delivered in nanoliposomes. The nanoliposomal formulation of mupirocin is a potential treatment for drug-resistant N. gonorrhoeae . Copyright © 2018 American Society for Microbiology.

  14. AtlA Functions as a Peptidoglycan Lytic Transglycosylase in the Neisseria gonorrhoeae Type IV Secretion System▿

    OpenAIRE

    Kohler, Petra L.; Hamilton, Holly L.; Cloud-Hansen, Karen; Dillard, Joseph P.

    2007-01-01

    Type IV secretion systems require peptidoglycan lytic transglycosylases for efficient secretion, but the function of these enzymes is not clear. The type IV secretion system gene cluster of Neisseria gonorrhoeae encodes two peptidoglycan transglycosylase homologues. One, LtgX, is similar to peptidoglycan transglycosylases from other type IV secretion systems. The other, AtlA, is similar to endolysins from bacteriophages and is not similar to any described type IV secretion component. We chara...

  15. Increase of Neisseria meningitidis W:cc11 invasive disease in Chile has no correlation with carriage in adolescents.

    Directory of Open Access Journals (Sweden)

    Paulina S Rubilar

    Full Text Available Neisseria meningitidis is a human exclusive pathogen that can lead to invasive meningococcal disease or may be carried in the upper respiratory tract without symptoms. The relationship between carriage and disease remains poorly understood but it is widely accepted that decreasing carriage by immunization should lead to a reduction of invasive cases. Latin America has experienced an increased incidence of serogroup W invasive cases of Neisseria meningitidis in the last decade. Specifically in Chile, despite low total incidence of invasive cases, serogroup W has become predominant since 2011 and has been associated with elevated mortality. Expecting to gain insight into the epidemiology of this disease, this study has used molecular typing schemes to compare Neisseria meningitidis isolates causing invasive disease with those isolates collected from adolescent carriers during the same period in Chile. A lower carriage of the serogroup W clonal complex ST-11/ET37 than expected was found; whereas, the same clonal complex accounted for 66% of total invasive meningococcal disease cases in the country that year. A high diversity of PorA variable regions and fHbp peptides was also ascertained in the carrier isolates compared to the invasive ones. According to the results shown here, the elevated number of serogroup W invasive cases in our country cannot be explained by a rise of carriage of pathogenic isolates. Overall, this study supports the idea that some strains, as W:cc11 found in Chile, possess an enhanced virulence to invade the host. Notwithstanding hypervirulence, this strain has not caused an epidemic in Chile. Finally, as genetic transfer occurs often, close surveillance of Neisseria meningitidis strains causing disease, and particularly hypervirulent W:cc11, should be kept as a priority in our country, in order to prepare the best response to face genetic changes that could lead to enhanced fitness of this pathogen.

  16. Crystal structure of the iron-regulated outer membrane lipoprotein FrpD (NMB0584) from Neisseria meningitidis

    Czech Academy of Sciences Publication Activity Database

    Sviridova, E.; Bumba, Ladislav; Řezáčová, Pavlína; Šebo, Peter; Kutá-Smatanová, Ivana

    2012-01-01

    Roč. 12, č. 1 (2012), s. 49-49 ISSN 1210-8529. [10th Discussions in Structural Molecular Biology. 22.03.2012-24.03.2012, Nové Hrady] R&D Projects: GA ČR(CZ) GAP207/11/0717 Institutional research plan: CEZ:AV0Z40550506; CEZ:AV0Z60870520; CEZ:AV0Z50200510 Keywords : Neisseria meningitidis * FrpD Subject RIV: EE - Microbiology, Virology

  17. Impact of the conjugate vaccine, MenAfriVac, on carriage of serogroup A Neisseria meningitidis and disease transmission

    OpenAIRE

    Kristiansen, Paul Arne

    2013-01-01

    Neisseria meningitidis (Nm), also referred to as meningococcus, is a human commensal colonising the oropharynx, transmittable by close contact between healthy people. The bacterium can act as an opportunistic pathogen and cause bacterial meningitis and septicaemia. Meningococci are classified into 12 serogroups based on the composition of their polysaccharide (Ps) capsule. Six of these serogroups, serogroups A, B, C, W, X and Y cause meningococcal disease worldwide. The populations most affec...

  18. Study of 138 Neisseria meningitidis strains isolated from blood or cerebrospinal fluid in Lombardy between 2007 and 2010

    Directory of Open Access Journals (Sweden)

    Laura Daprai

    2012-06-01

    Full Text Available Neisseria meningitidis, Streptococcus pneumoniae, and Haemophilus influenzae type b cause the majority of cases of bacterial septicaemia in children and young adults. Disease epidemiology is evolving rapidly due to the introduction of vaccines and changing in bacterial antibiotic-resistance patterns. (Asymptomatic nasopharyngeal colonization with Neisseria meningitides occurs in 5-10% of adult. The aim of this study was to calculate the frequency of each serogroup of this pathogens involved in invasive infection and to study susceptibility to antibiotics of these strains. Between March 2007 and June 2010 we received, from 43 hospitals of Lombardy, 138 strains of Neisseria meningitidis, from 138 patients aged (2-80yrs. The most frequent serogroup was B (58%, followed by serogroup C (34%, serogroup G (4% and W 135 (2%. Serogroup A end X accounted for 1% of invasive infection, each. We observed a decrease in susceptibility towards penicillin in 38% of strains. In addition we studied, by REP- PCR, genotype of 9 strains selected on the basis of epidemiological data.Among these strains, 3 different clusters according to the 3 small epidemic outbreaks occurred between June and September 2009, were recognised. Seven of these strains, although belonged to the same serogroup, brought about two different clusters. The present findings demonstrated that phenotypic data are not sufficient to define epidemic clusters, therefore molecular genotyping is required.

  19. Draft Genome Sequence of the Dimorphic Fungus Sporothrix pallida, a Nonpathogenic Species Belonging to Sporothrix, a Genus Containing Agents of Human and Feline Sporotrichosis

    NARCIS (Netherlands)

    D'Alessandro, Enrico; Giosa, Domenico; Huang, Lilin; Zhang, Jing; Gao, Wenchao; Brankovics, Balázs; Oliveira, Manoel Marques Evangelista; Scordino, Fabio; Lo Passo, Carla; Criseo, Giuseppe; van Diepeningen, Anne D; Huang, Huaiqiu; de Hoog, G Sybren; Romeo, Orazio

    2016-01-01

    Sporothrix pallidais considered to be a mostly avirulent environmental fungus, phylogenetically closely related to the well-known pathogenSporothrix schenckii Here, we present the first assembly of its genome, which provides a valuable resource for future comparative genomic studies between

  20. Methylobacteria isolated from bryophytes and the 2-fold description of the same microbial species

    OpenAIRE

    Schauer, S.; Kutschera, U.

    2013-01-01

    On the surface of healthy land plants (embryophytes), numerous non-pathogenic bacteria have been discovered and described. Among these epiphytic microbes, pink-pigmented facultative methylotrophic microbes of the genus Methylobacterium are of special significance, because these microorganisms consume methanol emitted via the stomatal pores and secrete growth-promoting phytohormones. Methylobacterium funariae, Schauer and Kutschera 2011, a species isolated in our lab from the common cord moss,...

  1. Decoding the similarities and differences among mycobacterial species.

    Directory of Open Access Journals (Sweden)

    Sony Malhotra

    2017-08-01

    Full Text Available Mycobacteriaceae comprises pathogenic species such as Mycobacterium tuberculosis, M. leprae and M. abscessus, as well as non-pathogenic species, for example, M. smegmatis and M. thermoresistibile. Genome comparison and annotation studies provide insights into genome evolutionary relatedness, identify unique and pathogenicity-related genes in each species, and explore new targets that could be used for developing new diagnostics and therapeutics. Here, we present a comparative analysis of ten-mycobacterial genomes with the objective of identifying similarities and differences between pathogenic and non-pathogenic species. We identified 1080 core orthologous clusters that were enriched in proteins involved in amino acid and purine/pyrimidine biosynthetic pathways, DNA-related processes (replication, transcription, recombination and repair, RNA-methylation and modification, and cell-wall polysaccharide biosynthetic pathways. For their pathogenicity and survival in the host cell, pathogenic species have gained specific sets of genes involved in repair and protection of their genomic DNA. M. leprae is of special interest owing to its smallest genome (1600 genes and ~1300 psuedogenes, yet poor genome annotation. More than 75% of the pseudogenes were found to have a functional ortholog in the other mycobacterial genomes and belong to protein families such as transferases, oxidoreductases and hydrolases.

  2. Effects of co-occurring Wolbachia and Spiroplasma endosymbionts on the Drosophila immune response against insect pathogenic and non-pathogenic bacteria.

    Science.gov (United States)

    Shokal, Upasana; Yadav, Shruti; Atri, Jaishri; Accetta, Julia; Kenney, Eric; Banks, Katherine; Katakam, Akash; Jaenike, John; Eleftherianos, Ioannis

    2016-02-09

    Symbiotic interactions between microbes and animals are common in nature. Symbiotic organisms are particularly common in insects and, in some cases, they may protect their hosts from pathogenic infections. Wolbachia and Spiroplasma endosymbionts naturally inhabit various insects including Drosophila melanogaster fruit flies. Therefore, this symbiotic association is considered an excellent model to investigate whether endosymbiotic bacteria participate in host immune processes against certain pathogens. Here we have investigated whether the presence of Wolbachia alone or together with Spiroplasma endosymbionts in D. melanogaster adult flies affects the immune response against the virulent insect pathogen Photorhabdus luminescens and against non-pathogenic Escherichia coli bacteria. We found that D. melanogaster flies carrying no endosymbionts, those carrying both Wolbachia and Spiroplasma, and those containing Wolbachia only had similar survival rates after infection with P. luminescens or Escherichia coli bacteria. However, flies carrying both endosymbionts or Wolbachia only contained higher numbers of E. coli cells at early time-points post infection than flies without endosymbiotic bacteria. Interestingly, flies containing Wolbachia only had lower titers of this endosymbiont upon infection with the pathogen P. luminescens than uninfected flies of the same strain. We further found that the presence of Wolbachia and Spiroplasma in D. melanogaster up-regulated certain immune-related genes upon infection with P. luminescens or E. coli bacteria, but it failed to alter the phagocytic ability of the flies toward E. coli inactive bioparticles. Our results suggest that the presence of Wolbachia and Spiroplasma in D. melanogaster can modulate immune signaling against infection by certain insect pathogenic and non-pathogenic bacteria. Results from such studies are important for understanding the molecular basis of the interactions between endosymbiotic bacteria of insects

  3. The ability of algal organic matter and surface runoff to promote the abundance of pathogenic and non-pathogenic strains of Vibrio parahaemolyticus in Long Island Sound, USA.

    Directory of Open Access Journals (Sweden)

    Jake D Thickman

    Full Text Available Food safety is a major concern in the shellfish industry, as severe illness can result from consuming shellfish that have accumulated waterborne pathogens. Shellfish harvesting areas are typically monitored for indicator bacteria such as fecal coliforms that serve as proxies for enteric pathogens although these indicators have shown little relation to some naturally occurring pathogenic bacteria such as Vibrio parahaemolyticus. To examine the dynamics and ecology of pathogenic and non-pathogenic strains of V. parahaemolyticus and address the relevance of indicator bacteria in predicting V. parahaemolyticus concentrations, field surveys and experiments were carried out in western Long Island Sound, NY, USA, a region that has experienced recent outbreaks of shellfish contaminated with V. parahaemolyticus. Pathogenic and non-pathogenic strains were quantified via PCR detection of marker genes and most probable number techniques. Field survey data showed little correspondence between fecal coliforms and V. parahaemolyticus, but significant correlations between V. parahaemolyticus and an alternative indicator, enterococci, and between V. parahaemolyticus and short-term (48 h rainfall were observed. Experiments demonstrated that enrichment of seawater with phytoplankton-derived dissolved organic matter significantly increased the concentration of total V. parahaemolyticus and the presence pathogenic V. parahaemolyticus, but higher temperatures did not. Collectively, these study results suggest that fecal coliforms may fail to account for the full suite of important shellfish pathogens but that enterococci could provide a potential alternative or supplement to shellfish sanitation monitoring. Given the ability of algal-derived dissolved organic matter to promote the growth of pathogenic V. parahaemolyticus, restricting nutrient inputs into coastal water bodies that promote algal blooms may indirectly decrease the proliferation of V. parahaemolyticus

  4. Enfermedad por meningococo, Neisseria meningitidis: perspectiva epidemiológica, clínica y preventiva Meningococcal disease caused by Neisseria meningitidis: epidemiological, clinical, and preventive perspectives

    Directory of Open Access Journals (Sweden)

    Lourdes Almeida-González

    2004-10-01

    Full Text Available La meningitis bacteriana continúa siendo uno de los grandes problemas de la salud pública mundial. En particular, la infección por Neisseria meningitidis afecta tanto a países desarrollados como subdesarrollados, y se presenta en formas endémicas y epidémicas. La enfermedad meningocóccica se puede manifestar clínicamente no sólo como meningitis, sino con cuadros fulminantes de meningococcemia. La persistencia de N. meningitidis se debe al gran porcentaje de portadores y a la dinámica de transmisión de la bacteria. Aproximadamente 500 millones de personas en el mundo son portadoras de N. meningitidis en la nasofaringe. Los factores de transmisiblidad identificados han sido el tabaquismo activo o pasivo, la presencia de infecciones virales del tracto respiratorio superior, épocas de sequía, y el hacinamiento. Por lo anterior, se han descrito brotes de enfermedad meningocóccica en cuarteles militares, escuelas, cárceles y dormitorios. Algunos determinantes que permiten la invasión sistémica incluyen daños en la mucosa nasofaríngea de portadores, cepas virulentas con formación de cápsula, ausencia de anticuerpos bactericidas y deficiencias del sistema del complemento. El control de la enfermedad meningocóccica en circunstancias endémicas y epidémicas se logra por el tratamiento de casos con antibióticos adecuados (penicilina, ceftriaxona o cloranfenicol, la quimioprofilaxis de contactos cercanos (ciprofloxacina, rifampicina o ceftriaxona, y la vigilancia clínica de éstos. Sin embargo, es fundamental subrayar que la clave para el control efectivo de la enfermedad meningocóccica es la inmunoprofilaxis. Las vacunas disponibles incluyen las de polisacáridos monovalentes o bivalentes (serogrupos A y C, tetravalentes (A, C, Y, W-135, la conjugada (C o la combinada de proteínas de membrana celular y polisacárido (B y C. Recientemente nos hemos visto forzados a establecer planes nacionales de respuesta que incluyen la

  5. Escherichia coli and Neisseria gonorrhoeae UvrD helicase unwinds G4 DNA structures.

    Science.gov (United States)

    Shukla, Kaustubh; Thakur, Roshan Singh; Ganguli, Debayan; Rao, Desirazu Narasimha; Nagaraju, Ganesh

    2017-10-18

    G-quadruplex (G4) secondary structures have been implicated in various biological processes, including gene expression, DNA replication and telomere maintenance. However, unresolved G4 structures impede replication progression which can lead to the generation of DNA double-strand breaks and genome instability. Helicases have been shown to resolve G4 structures to facilitate faithful duplication of the genome. Escherichia coli UvrD (EcUvrD) helicase plays a crucial role in nucleotide excision repair, mismatch repair and in the regulation of homologous recombination. Here, we demonstrate a novel role of E. coli and Neisseria gonorrhoeae UvrD in resolving G4 tetraplexes. EcUvrD and N gonorrhoeae UvrD were proficient in unwinding previously characterized tetramolecular G4 structures. Notably, EcUvrD was equally efficient in resolving tetramolecular and bimolecular G4 DNA that were derived from the potential G4-forming sequences from the genome of E. coli Interestingly, in addition to resolving intermolecular G4 structures, EcUvrD was robust in unwinding intramolecular G4 structures. These data for the first time provide evidence for the role of UvrD in the resolution of G4 structures, which has implications for the in vivo role of UvrD helicase in G4 DNA resolution and genome maintenance. © 2017 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.

  6. Bim and Bmf synergize to induce apoptosis in Neisseria gonorrhoeae infection.

    Directory of Open Access Journals (Sweden)

    Oliver Kepp

    2009-03-01

    Full Text Available Bcl-2 family proteins including the pro-apoptotic BH3-only proteins are central regulators of apoptotic cell death. Here we show by a focused siRNA miniscreen that the synergistic action of the BH3-only proteins Bim and Bmf is required for apoptosis induced by infection with Neisseria gonorrhoeae (Ngo. While Bim and Bmf were associated with the cytoskeleton of healthy cells, they both were released upon Ngo infection. Loss of Bim and Bmf from the cytoskeleton fraction required the activation of Jun-N-terminal kinase-1 (JNK-1, which in turn depended on Rac-1. Depletion and inhibition of Rac-1, JNK-1, Bim, or Bmf prevented the activation of Bak and Bax and the subsequent activation of caspases. Apoptosis could be reconstituted in Bim-depleted and Bmf-depleted cells by additional silencing of antiapoptotic Mcl-1 and Bcl-X(L, respectively. Our data indicate a synergistic role for both cytoskeletal-associated BH3-only proteins, Bim, and Bmf, in an apoptotic pathway leading to the clearance of Ngo-infected cells.

  7. Neisseria gonorrhoeae DNA bacterial load in men with symptomatic and asymptomatic gonococcal urethritis.

    Science.gov (United States)

    Priest, David; Ong, Jason J; Chow, Eric P F; Tabrizi, Sepehr; Phillips, Sam; Bissessor, Melanie; Fairley, Christopher K; Bradshaw, Catriona S; Read, Tim R H; Garland, Suzanne; Chen, Marcus

    2017-11-01

    Previous studies have quantified bacterial loads of Neisseria gonorrhoeae in the pharynx and rectum of men but not the urethra. We quantified the bacterial load of N. gonorrhoeae in men with symptomatic and asymptomatic urethral gonorrhoea infections. Consecutive men diagnosed with urethral gonorrhoea by Aptima Combo 2 testing of urine at the Melbourne Sexual Health Centre between March and July 2016 were eligible for the study: symptomatic men with purulent urethral discharge and asymptomatic men with no urethral symptoms. The gonococcal bacterial load in both groups was measured by urethral swab using a standardised collection method and real-time quantitative PCR targeting the opa gene. Twenty men were recruited into the study: 16 had purulent urethral discharge and 4 had asymptomatic urethral gonorrhoea. The median gonococcal bacterial load was significantly higher among symptomatic men (3.7×10 6 copies per swab, IQR 2.5×10 6 -4.7×10 6 ) compared with asymptomatic men (2.0×10 5 copies per swab, IQR 2.7×10 4 -4.5×10 5 ) (p=0.002). Gonococcal loads in men with urethral discharge were higher than loads seen with asymptomatic urethral gonorrhoea and loads seen in asymptomatic pharyngeal and rectal gonorrhoea infections in previous studies. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  8. Nasopharyngeal Carriage Rate and Serogroups of Neisseria meningitidis in Turkish recruits upon entry to the military

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    Ahmet Basustaoglu

    2011-08-01

    Full Text Available Aim: The aim of this study was to determine nasopharyngeal carriage rate and serogroup of Neisseria meningitidis strains isolated from Turkish recruits upon entry to the military. Material and Methods: Nasopharyngeal swab samples were obtained from 1995 soldiers and were inoculated immediately on BBL-modified Thayer-Martin medium plates. The plates were examined for the presence of colonies showing the typical morphology of N. meningitidis. Suspect colonies were screened for oxidase reactivity, and positive colonies were Gram stained. If Gram-negative diplococci were present, a biochemical profile by the API NH system was used for confirmation. Serogrouping of the meningococcal isolates was performed by a slide agglutination technique. Findings: The nasopharyngeal carriage rate of N. meningitidis was found to be 4.2% (n=83. Of these meningococci, 15.6% (n=13 were serogroup Y, 10.8% (n=9 were serogroup W-135, 9.6% (n=8 were serogroup C, 6.1% (n=5 were serogroup B, 2.4% (n=2 were serogroup A. The 46 isolates (55.4% were detected as nonserogroupable. Conclusion: Since serogroup Y and W-135 are predominant in this study population, it was suggest that Turkish recruits should be vaccinated by quadrivalent vaccine (A,C,Y, and W-135 upon the military instead of A+C polysaccharide vaccine and now quadrivalent vaccine has been carried out. [TAF Prev Med Bull 2011; 10(4.000: 447-450

  9. Rapid Laboratory Identification of Neisseria meningitidis Serogroup C as the Cause of an Outbreak - Liberia, 2017.

    Science.gov (United States)

    Patel, Jaymin C; George, Josiah; Vuong, Jeni; Potts, Caelin C; Bozio, Catherine; Clark, Thomas A; Thomas, Jerry; Schier, Joshua; Chang, Arthur; Waller, Jessica L; Diaz, Maureen H; Whaley, Melissa; Jenkins, Laurel T; Fuller, Serena; Williams, Desmond E; Redd, John T; Arthur, Ray R; Taweh, Fahn; Vera Walker, Yatta; Hardy, Patrick; Freeman, Maxwell; Katawera, Victoria; Gwesa, Gulu; Gbanya, Miatta Z; Clement, Peter; Kohar, Henry; Stone, Mardia; Fallah, Mosoka; Nyenswah, Tolbert; Winchell, Jonas M; Wang, Xin; McNamara, Lucy A; Dokubo, E Kainne; Fox, LeAnne M

    2017-10-27

    On April 25, 2017, a cluster of unexplained illness and deaths among persons who had attended a funeral during April 21-22 was reported in Sinoe County, Liberia (1). Using a broad initial case definition, 31 cases were identified, including 13 (42%) deaths. Twenty-seven cases were from Sinoe County (1), and two cases each were from Grand Bassa and Monsterrado counties, respectively. On May 5, 2017, initial multipathogen testing of specimens from four fatal cases using the Taqman Array Card (TAC) assay identified Neisseria meningitidis in all specimens. Subsequent testing using direct real-time polymerase chain reaction (PCR) confirmed N. meningitidis in 14 (58%) of 24 patients with available specimens and identified N. meningitidis serogroup C (NmC) in 13 (54%) patients. N. meningitidis was detected in specimens from 11 of the 13 patients who died; no specimens were available from the other two fatal cases. On May 16, 2017, the National Public Health Institute of Liberia and the Ministry of Health of Liberia issued a press release confirming serogroup C meningococcal disease as the cause of this outbreak in Liberia.

  10. Parameter and state estimation in a Neisseria meningitidis model: A study case of Niger

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    Bowong, S.; Mountaga, L.; Bah, A.; Tewa, J. J.; Kurths, J.

    2016-12-01

    Neisseria meningitidis (Nm) is a major cause of bacterial meningitidis outbreaks in Africa and the Middle East. The availability of yearly reported meningitis cases in the African meningitis belt offers the opportunity to analyze the transmission dynamics and the impact of control strategies. In this paper, we propose a method for the estimation of state variables that are not accessible to measurements and an unknown parameter in a Nm model. We suppose that the yearly number of Nm induced mortality and the total population are known inputs, which can be obtained from data, and the yearly number of new Nm cases is the model output. We also suppose that the Nm transmission rate is an unknown parameter. We first show how the recruitment rate into the population can be estimated using real data of the total population and Nm induced mortality. Then, we use an auxiliary system called observer whose solutions converge exponentially to those of the original model. This observer does not use the unknown infection transmission rate but only uses the known inputs and the model output. This allows us to estimate unmeasured state variables such as the number of carriers that play an important role in the transmission of the infection and the total number of infected individuals within a human community. Finally, we also provide a simple method to estimate the unknown Nm transmission rate. In order to validate the estimation results, numerical simulations are conducted using real data of Niger.

  11. Synthesis and immunological evaluation of protein conjugates of Neisseria meningitidis X capsular polysaccharide fragments

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    Laura Morelli

    2014-10-01

    Full Text Available A vaccine to prevent infections from the emerging Neisseria meningitidis X (MenX is becoming an urgent issue. Recently MenX capsular polysaccharide (CPS fragments conjugated to CRM197 as carrier protein have been confirmed at preclinical stage as promising candidates for vaccine development. However, more insights about the minimal epitope required for the immunological activity of MenX CPS are needed. We report herein the chemical conjugation of fully synthetic MenX CPS oligomers (monomer, dimer, and trimer to CRM197. Moreover, improvements in some crucial steps leading to the synthesis of MenX CPS fragments are described. Following immunization with the obtained neoglycoconjugates, the conjugated trimer was demonstrated as the minimal fragment possessing immunogenic activity, even though significantly lower than a pentadecamer obtained from the native polymer and conjugated to the same protein. This finding suggests that oligomers longer than three repeating units are possibly needed to mimic the activity of the native polysaccharide.

  12. Nationwide surveillance of the antimicrobial susceptibility of Neisseria gonorrhoeae from male urethritis in Japan.

    Science.gov (United States)

    Hamasuna, Ryoichi; Yasuda, Mitsuru; Ishikawa, Kiyohito; Uehara, Shinya; Takahashi, Satoshi; Hayami, Hiroshi; Yamamoto, Shingo; Matsumoto, Tetsuro; Minamitani, Shinichi; Watanabe, Akira; Iwamoto, Aikichi; Totsuka, Kyoichi; Kadota, Junichi; Sunakawa, Keisuke; Sato, Junko; Hanaki, Hideaki; Tsukamoto, Taiji; Kiyota, Hiroshi; Egawa, Shin; Tanaka, Kazushi; Arakawa, Soichi; Fujisawa, Masato; Kumon, Hiromi; Kobayashi, Kanao; Matsubara, Akio; Naito, Seiji; Tatsugami, Katsunori; Ito, Shin; Narita, Harunori; Kanokogi, Mototsugu; Sumii, Toru; Ito, Kenji; Hosobe, Takahide; Kawai, Shuichi; Kawano, Hiromi; Takayama, Kazuo; Yamaguchi, Takamasa; Endo, Katsuhisa; Yamauchi, Takamine; Maeda, Shinichi; Yoh, Mutsumasa; Horie, Masanobu; Ito, Masayasu; Chokyu, Hirofumi; Ihara, Hideari; Akiyama, Kikuo; Uno, Satoshi; Monden, Koichi; Kaji, Shinichi; Nishimura, Hirofumi; Kawahara, Motoshi; Sato, Takashi; Konishi, Takatoshi; Nishi, Shohei; Ishihara, Satoshi; Yoshioka, Masaru

    2013-08-01

    Neisseria gonorrhoeae is one of the most important pathogens causing sexually transmitted infection, and strains that are resistant to several antimicrobials are increasing. To investigate the trends of antimicrobial susceptibility among N. gonorrhoeae strains isolated from male patients with urethritis, a Japanese surveillance committee conducted the first nationwide surveillance. The urethral discharge was collected from male patients with urethritis at 51 medical facilities from April 2009 to October 2010. Of the 156 specimens, 83 N. gonorrhoeae strains were tested for susceptibility to 18 antimicrobial agents. The prevalence of β-lactamase-producing strains and chromosomally mediated resistant strains were 7.2 % and 16.5 %, respectively. None of the strains was resistant to ceftriaxone, but the minimum inhibitory concentration (MIC) of ceftriaxone for 7 strains (8.4 %) was 0.125 μg/ml. One strain was resistant to cefixime (MIC 0.5 μg/ml). The MICs of fluoroquinolones, such as ciprofloxacin, levofloxacin, and tosufloxacin, showed a bimodal distribution. The MIC of sitafloxacin was lower than those of the three fluoroquinolones listed here, and it was found that the antimicrobial activity of sitafloxacin was stronger than that of the fluoroquinolones. The MIC of azithromycin in 2 strains was 2 μg/ml, but no high-level resistance to macrolides was detected.

  13. Non-cytotoxic nanomaterials enhance antimicrobial activities of cefmetazole against multidrug-resistant Neisseria gonorrhoeae.

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    Lan-Hui Li

    Full Text Available The emergence and spread of antibiotic-resistant Neisseria gonorrhoeae has led to difficulties in treating patients, and novel strategies to prevent and treat this infection are urgently needed. Here, we examined 21 different nanomaterials for their potential activity against N. gonorrhoeae (ATCC 49226. Silver nanoparticles (Ag NPs, 120 nm showed the greatest potency for reducing N. gonorrhoeae colony formation (MIC: 12.5 µg/ml and possessed the dominant influence on the antibacterial activity with their properties of the nanoparticles within a concentration range that did not induce cytotoxicity in human fibroblasts or epithelial cells. Electron microscopy revealed that the Ag NPs significantly reduced bacterial cell membrane integrity. Furthermore, the use of clinical isolates of multidrug-resistant N. gonorrhoeae showed that combined treatment with 120 nm Ag NPs and cefmetazole produced additive effects. This is the first report to screen the effectiveness of nanomaterials against N. gonorrhoeae, and our results indicate that 120 nm Ag NPs deliver low levels of toxicity to human epithelial cells and could be used as an adjuvant with antibiotic therapy, either for topical use or as a coating for biomaterials, to prevent or treat multidrug-resistant N. gonorrhoeae.

  14. Effects of multi-walled carbon nanotubes (MWCNT under Neisseria meningitidis transformation process

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    Mattos Ives B

    2011-11-01

    Full Text Available Abstract Background This study aimed at verifying the action of multi-walled carbon nanotubes (MWCNT under the naturally transformable Neisseria meningitidis against two different DNA obtained from isogenic mutants of this microorganism, an important pathogen implicated in the genetic horizontal transfer of DNA, causing the escape of the principal vaccination measured worldwide by the capsular switching process. Materials and methods The bacterium receptor strain C2135 was cultivated and had its mutant DNA donor M2 and M6, which received a receptor strain and MWCNT at three different concentrations. The inhibition effect of DNAse on the DNA in contact with nanoparticles was evaluated. Results The results indicated an in increase in the transformation capacity of N. meninigtidis in different concentrations of MWCNT when compared with negative control without nanotubes. A final analysis of the interaction between DNA and MWCNT was carried out using Raman Spectroscopy. Conclusion These increases in the transformation capacity mediated by MWCNT, in meningococci, indicate the interaction of these particles with the virulence acquisition of these bacteria, as well as with the increase in the vaccination escape process.

  15. Prevention of Ophthalmia Neonatorum Caused by Neisseria gonorrhoeae Using a Fatty Acid-Based Formulation

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    Colin P. Churchward

    2017-07-01

    Full Text Available Ophthalmia neonatorum, also called neonatal conjunctivitis, acquired during delivery can occur in the first 28 days of life. Commonly caused by the bacterial pathogen Neisseria gonorrhoeae, infection can lead to corneal scarring, perforation of the eye, and blindness. One approach that can be taken to prevent the disease is the use of an ophthalmic prophylaxis, which kills the bacteria on the surface of the eye shortly after birth. Current prophylaxes are based on antibiotic ointments. However, N. gonorrhoeae is resistant to many antibiotics and alternative treatments must be developed before the condition becomes untreatable. This study focused on developing a fatty acid-based prophylaxis. For this, 37 fatty acids or fatty acid derivatives were screened in vitro for fast antigonococcal activity. Seven candidates were identified as bactericidal at 1 mM. These seven were subjected to irritation testing using three separate methods: the bovine corneal opacity and permeability (BCOP test; the hen’s egg test—chorioallantoic membrane (HET-CAM; and the red blood cell (RBC lysis assay. The candidates were also tested in artificial tear fluid to determine whether they were effective in this environment. Four of the candidates remained effective. Among these, two lead candidates, monocaprin and myristoleic acid, displayed the best potential as active compounds in the development of a fatty acid-based prophylaxis for prevention of ophthalmia neonatorum.

  16. A Systematic Review of Point of Care Testing for Chlamydia trachomatis, Neisseria gonorrhoeae, and Trichomonas vaginalis

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    Sasha Herbst de Cortina

    2016-01-01

    Full Text Available Objectives. Systematic review of point of care (POC diagnostic tests for sexually transmitted infections: Chlamydia trachomatis (CT, Neisseria gonorrhoeae (NG, and Trichomonas vaginalis (TV. Methods. Literature search on PubMed for articles from January 2010 to August 2015, including original research in English on POC diagnostics for sexually transmitted CT, NG, and/or TV. Results. We identified 33 publications with original research on POC diagnostics for CT, NG, and/or TV. Thirteen articles evaluated test performance, yielding at least one test for each infection with sensitivity and specificity ≥90%. Each infection also had currently available tests with sensitivities <60%. Three articles analyzed cost effectiveness, and five publications discussed acceptability and feasibility. POC testing was acceptable to both providers and patients and was also demonstrated to be cost effective. Fourteen proof of concept articles introduced new tests. Conclusions. Highly sensitive and specific POC tests are available for CT, NG, and TV, but improvement is possible. Future research should focus on acceptability, feasibility, and cost of POC testing. While pregnant women specifically have not been studied, the results available in nonpregnant populations are encouraging for the ability to test and treat women in antenatal care to prevent adverse pregnancy and neonatal outcomes.

  17. Arginine- and Polyamine-Induced Lactic Acid Resistance in Neisseria gonorrhoeae.

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    Zheng Gong

    Full Text Available Microbe-derived lactic acid protects women from pathogens in their genital tract. The purpose of this study was to determine lactic acid susceptibility of Neisseria gonorrhoeae, and identify potential acid resistance mechanisms present in this pathogen. Tested in vitro, lactic acid killed all 10 gonococcal strains analyzed in a low pH-dependent manner. Full inactivation occurred at pH 4.5. At low pH, lactic acid treatment resulted in the entry of the DNA-binding fluorochrome propidium iodide into the microbial cells, suggesting that hydrogen ions from lactic acid compromise the integrity of the bacterial cell wall/membrane. Most likely, hydrogen ions also inactivate intracellular proteins since arginine rendered significant protection against lactic acid presumably through action of the gonococcal arginine decarboxylase, an enzyme located in the bacterial cytoplasm. Surprisingly, arginine also lessened lactic acid-mediated cell wall/membrane disruption. This effect is probably mediated by agmatine, a triamine product of arginine decarboxylase, since agmatine demonstrated a stronger protective effect on GC than arginine at equal molar concentration. In addition to agmatine, diamines cadaverine and putrescine, which are generated by bacterial vaginosis-associated microbes, also induced significant resistance to lactic acid-mediated GC killing and cell wall/membrane disruption. These findings suggest that the arginine-rich semen protects gonococci through both neutralization-dependent and independent mechanisms, whereas polyamine-induced acid resistance contributes to the increased risk of gonorrhea in women with bacterial vaginosis.

  18. Variation of Neisseria gonorrhoeae lipooligosaccharide directs dendritic cell-induced T helper responses.

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    Sandra J van Vliet

    2009-10-01

    Full Text Available Gonorrhea is one of the most prevalent sexually transmitted diseases in the world. A naturally occurring variation of the terminal carbohydrates on the lipooligosaccharide (LOS molecule correlates with altered disease states. Here, we investigated the interaction of different stable gonoccocal LOS phenotypes with human dendritic cells and demonstrate that each variant targets a different set of receptors on the dendritic cell, including the C-type lectins MGL and DC-SIGN. Neisseria gonorrhoeae LOS phenotype C constitutes the first bacterial ligand to be described for the human C-type lectin receptor MGL. Both MGL and DC-SIGN are locally expressed at the male and female genital area, the primary site of N. gonorrhoeae infection. We show that targeting of different C-type lectins with the N. gonorrhoeae LOS variants results in alterations in dendritic cell cytokine secretion profiles and the induction of distinct adaptive CD4(+ T helper responses. Whereas N. gonorrhoeae variant A with a terminal N-acetylglucosamine on its LOS was recognized by DC-SIGN and induced significantly more IL-10 production, phenotype C, carrying a terminal N-acetylgalactosamine, primarily interacted with MGL and skewed immunity towards the T helper 2 lineage. Together, our results indicate that N. gonorrhoeae LOS variation allows for selective manipulation of dendritic cell function, thereby shifting subsequent immune responses in favor of bacterial survival.

  19. Antibodies with higher bactericidal activity induced by a Neisseria gonorrhoeae Rmp deletion mutant strain.

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    Guocai Li

    Full Text Available Neisseria gonorrhoeae (N. gonorrhoeae outer membrane protein reduction modifiable protein (Rmp has strong immunogenicity. However, anti-Rmp antibodies block rather than preserve the antibacterial effects of protective antibodies, which hampers the development of vaccines for gonococcal infections. We herein constructed an Rmp deletion mutant strain of N. gonorrhoeae by gene homologous recombination. The 261-460 nucleotide residues of Rmp gene amplified from N. gonorrhoeae WHO-A strain were replaced with a kanamycin-resistant Kan gene amplified from pET-28a. The resultant hybridized DNA was transformed into N. gonorrhoeae WHO-A strain. PCR was used to screen the colonies in which wild-type Rmp gene was replaced with a mutant gene fragment. Western blotting revealed that the Rmp deletion mutant strain did not express Rmp protein. Rmp deletion did not alter the morphological and Gram staining properties of the mutant strain that grew slightly more slowly than the wild-type one. Rmp gene mutated stably throughout 25 generations of passage. Antibody-mediated complement-dependent cytotoxicity assay indicated that the antibodies induced by the mutant strain had evidently higher bactericidal activities than those induced by the wild-type strain. Further modification of the Rmp deletion mutant strain is still required in the development of novel live attenuated vaccines for gonorrhea by Opa genes deletion or screening of phenotypic variant strains that do not express Opa proteins.

  20. Mutation in ribosomal protein S5 leads to spectinomycin resistance in Neisseria gonorrhoeae.

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    Elena eIlina

    2013-07-01

    Full Text Available Spectinomycin remains a useful reserve option for therapy of gonorrhea. The emergence of multidrug-resistant Neisseria gonorrhoeae strains with decreased susceptibility to cefixime and to ceftriaxone makes it the only medicine still effective for treatment of gonorrhea infection in analogous cases. However, adoption of spectinomycin as a routinely used drug of choice was soon followed by reports of spectinomycin resistance. The main molecular mechanism of spectinomycin resistance in N. gonorrhoeae was C1192T substitution in 16S rRNA genes. Here we reported a Thr-24→Pro mutation in ribosomal protein S5 found in spectinomycin resistant clinical N. gonorrhoeae strain, which carried no changes in 16S rRNA. In a series of experiments, the transfer of rpsE gene allele encoding the mutant ribosomal protein S5 to the recipient N. gonorrhoeae strains was analyzed. The relatively high rate of transformation (ca. 10-5 CFUs indicates the possibility of spread of spectinonycin resistance within gonococcal population due to the horizontal gene transfer.

  1. Structure and Function of Neisseria gonorrhoeae MtrF Illuminates a Class of Antimetabolite Efflux Pumps

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    Chih-Chia Su

    2015-04-01

    Full Text Available Neisseria gonorrhoeae is an obligate human pathogen and the causative agent of the sexually transmitted disease gonorrhea. The control of this disease has been compromised by the increasing proportion of infections due to antibiotic-resistant strains, which are growing at an alarming rate. N. gonorrhoeae MtrF is an integral membrane protein that belongs to the AbgT family of transporters for which no structural information is available. Here, we describe the crystal structure of MtrF, revealing a dimeric molecule with architecture distinct from all other families of transporters. MtrF is a bowl-shaped dimer with a solvent-filled basin extending from the cytoplasm to halfway across the membrane bilayer. Each subunit of the transporter contains nine transmembrane helices and two hairpins, posing a plausible pathway for substrate transport. A combination of the crystal structure and biochemical functional assays suggests that MtrF is an antibiotic efflux pump mediating bacterial resistance to sulfonamide antimetabolite drugs.

  2. Phosphoethanolamine Modification of Neisseria gonorrhoeae Lipid A Reduces Autophagy Flux in Macrophages.

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    Susu M Zughaier

    Full Text Available Autophagy, an ancient homeostasis mechanism for macromolecule degradation, performs an important role in host defense by facilitating pathogen elimination. To counteract this host defense strategy, bacterial pathogens have evolved a variety of mechanisms to avoid or otherwise dysregulate autophagy by phagocytic cells so as to enhance their survival during infection. Neisseria gonorrhoeae is a strictly human pathogen that causes the sexually transmitted infection, gonorrhea. Phosphoethanolamine (PEA addition to the 4' position of the lipid A (PEA-lipid A moiety of the lipooligosaccharide (LOS produced by gonococci performs a critical role in this pathogen's ability to evade innate defenses by conferring decreased susceptibility to cationic antimicrobial (or host-defense peptides, complement-mediated killing by human serum and intraleukocytic killing by human neutrophils compared to strains lacking this PEA decoration. Heretofore, however, it was not known if gonococci can evade autophagy and if so, whether PEA-lipid A contributes to this ability. Accordingly, by using murine macrophages and human macrophage-like phagocytic cell lines we investigated if PEA decoration of gonococcal lipid A modulates autophagy formation. We report that infection with PEA-lipid A-producing gonococci significantly reduced autophagy flux in murine and human macrophages and enhanced gonococcal survival during their association with macrophages compared to a PEA-deficient lipid A mutant. Our results provide further evidence that PEA-lipid A produced by gonococci is a critical component in the ability of this human pathogen to evade host defenses.

  3. Neisseria meningitidis antigen NMB0088: sequence variability, protein topology and vaccine potential.

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    Sardiñas, Gretel; Yero, Daniel; Climent, Yanet; Caballero, Evelin; Cobas, Karem; Niebla, Olivia

    2009-02-01

    The significance of Neisseria meningitidis serogroup B membrane proteins as vaccine candidates is continually growing. Here, we studied different aspects of antigen NMB0088, a protein that is abundant in outer-membrane vesicle preparations and is thought to be a surface protein. The gene encoding protein NMB0088 was sequenced in a panel of 34 different meningococcal strains with clinical and epidemiological relevance. After this analysis, four variants of NMB0088 were identified; the variability was confined to three specific segments, designated VR1, VR2 and VR3. Secondary structure predictions, refined with alignment analysis and homology modelling using FadL of Escherichia coli, revealed that almost all the variable regions were located in extracellular loop domains. In addition, the NMB0088 antigen was expressed in E. coli and a procedure for obtaining purified recombinant NMB0088 is described. The humoral immune response elicited in BALB/c mice was measured by ELISA and Western blotting, while the functional activity of these antibodies was determined in a serum bactericidal assay and an animal protection model. After immunization in mice, the recombinant protein was capable of inducing a protective response when it was administered inserted into liposomes. According to our results, the recombinant NMB0088 protein may represent a novel antigen for a vaccine against meningococcal disease. However, results from the variability study should be considered for designing a cross-protective formulation in future studies.

  4. Lipoprotein NMB0928 from Neisseria meningitidis serogroup B as a novel vaccine candidate.

    Science.gov (United States)

    Delgado, Maité; Yero, Daniel; Niebla, Olivia; González, Sonia; Climent, Yanet; Pérez, Yusleydis; Cobas, Karem; Caballero, Evelín; García, Darien; Pajón, Rolando

    2007-12-05

    Polysaccharide-based vaccines for serogroup B Neisseria meningitidis have failed to induce protective immunity. As a result, efforts to develop vaccines for serogroup B meningococcal disease have mostly focused on outer membrane proteins (OMP). Vaccine candidates based on meningococcal OMP have emerged in the form of outer membrane vesicles (OMVs) or, more recently, purified recombinant proteins, as alternative strategies for serogroup B vaccine development. In our group, the protein composition of the Cuban OMVs-based vaccine VA-MENGOC-BC was elucidated using two-dimensional gel electrophoresis and mass spectrometry. The proteomic map of this product allowed the identification of new putative protective proteins not previously reported as components of an antimeningococcal vaccine. In the present study, we have determined the immunogenicity and protective capacity of NMB0928, one of those proteins present in the OMVs. The antigen was obtained as a recombinant protein in Escherichia coli, purified and used to immunize mice. The antiserum produced against the protein was capable to recognize the natural protein in different meningococcal strains by whole-cell ELISA and Western blotting. After immunization, recombinant NMB0928 induced bactericidal antibodies, and when the protein was administered inserted into liposomes, the elicited antibodies were protective in the infant rat model. These results suggest that NMB0928 is a novel antigen worth to be included in a broadly protective meningococcal vaccine.

  5. Structural and Biochemical Characterization of the Oxidoreductase NmDsbA3 from Neisseria meningitidis

    Energy Technology Data Exchange (ETDEWEB)

    Vivian, Julian P.; Scoullar, Jessica; Robertson, Amy L.; Bottomley, Stephen P.; Horne, James; Chin, Yanni; Wielens, Jerome; Thompson, Philip E.; Velkov, Tony; Piek, Susannah; Byres, Emma; Beddoe, Travis; Wilce, Matthew C.J.; Kahler, Charlene M.; Rossjohn, Jamie; Scanlon, Martin J. (UWA); (Monash)

    2009-09-02

    DsbA is an enzyme found in the periplasm of Gram-negative bacteria that catalyzes the formation of disulfide bonds in a diverse array of protein substrates, many of which are involved in bacterial pathogenesis. Although most bacteria possess only a single essential DsbA, Neisseria meningitidis is unusual in that it possesses three DsbAs, although the reason for this additional redundancy is unclear. Two of these N. meningitidis enzymes (NmDsbA1 and NmDsbA2) play an important role in meningococcal attachment to human epithelial cells, whereas NmDsbA3 is considered to have a narrow substrate repertoire. To begin to address the role of DsbAs in the pathogenesis of N. meningitidis, we have determined the structure of NmDsbA3 to 2.3-{angstrom} resolution. Although the sequence identity between NmDsbA3 and other DsbAs is low, the NmDsbA3 structure adopted a DsbA-like fold. Consistent with this finding, we demonstrated that NmDsbA3 acts as a thiol-disulfide oxidoreductase in vitro and is reoxidized by Escherichia coli DsbB (EcDsbB). However, pronounced differences in the structures between DsbA3 and EcDsbA, which are clustered around the active site of the enzyme, suggested a structural basis for the unusual substrate specificity that is observed for NmDsbA3.

  6. Methods for identifying Neisseria meningitidis carriers: a multi-center study in the African meningitis belt.

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    Nicole E Basta

    Full Text Available Detection of meningococcal carriers is key to understanding the epidemiology of Neisseria meningitidis, yet no gold standard has been established. Here, we directly compare two methods for collecting pharyngeal swabs to identify meningococcal carriers.We conducted cross-sectional surveys of schoolchildren at multiple sites in Africa to compare swabbing the posterior pharynx behind the uvula (U to swabbing the posterior pharynx behind the uvula plus one tonsil (T. Swabs were cultured immediately and analyzed using molecular methods.One thousand and six paired swab samples collected from schoolchildren in four countries were analyzed. Prevalence of meningococcal carriage was 6.9% (95% CI: 5.4-8.6% based on the results from both swabs, but the observed prevalence was lower based on one swab type alone. Prevalence based on the T swab or the U swab alone was similar (5.2% (95% CI: 3.8-6.7% versus 4.9% (95% CI: 3.6-6.4% respectively (p=0.6. The concordance between the two methods was 96.3% and the kappa was 0.61 (95% CI: 0.50-0.73, indicating good agreement.These two commonly used methods for collecting pharyngeal swabs provide consistent estimates of the prevalence of carriage, but both methods misclassified carriers to some degree, leading to underestimates of the prevalence.

  7. Structural basis for solute transport, nucleotide regulation, and immunological recognition of Neisseria meningitidis PorB

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    Tanabe, Mikio; Nimigean, Crina M.; Iverson, T.M. (Weill-Med); (Vanderbilt)

    2010-06-25

    PorB is the second most prevalent outer membrane protein in Neisseria meningitidis. PorB is required for neisserial pathogenesis and can elicit a Toll-like receptor mediated host immune response. Here, the x-ray crystal structure of PorB has been determined to 2.3 {angstrom} resolution. Structural analysis and cocrystallization studies identify three putative solute translocation pathways through the channel pore: One pathway transports anions nonselectively, one transports cations nonselectively, and one facilitates the specific uptake of sugars. During infection, PorB likely binds host mitochondrial ATP, and cocrystallization with the ATP analog AMP-PNP suggests that binding of nucleotides regulates these translocation pathways both by partial occlusion of the pore and by restricting the motion of a putative voltage gating loop. PorB is located on the surface of N. meningitidis and can be recognized by receptors of the host innate immune system. Features of PorB suggest that Toll-like receptor mediated recognition outer membrane proteins may be initiated with a nonspecific electrostatic attraction.

  8. Improved production process for native outer membrane vesicle vaccine against Neisseria meningitidis.

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    Bas van de Waterbeemd

    Full Text Available An improved detergent-free process has been developed to produce vaccine based on native outer membrane vesicles (NOMV against Neisseria meningitidis serogroup B. Performance was evaluated with the NonaMen vaccine concept, which provides broad coverage based on nine distinct PorA antigens. Scalable aseptic equipment was implemented, replacing undesirable steps like ultracentrifugation, inactivation with phenol, and the use of preservatives. The resulting process is more consistent and gives a higher yield than published reference processes, enabling NOMV production at commercial scale. Product quality met preliminary specifications for 9 consecutive batches, and an ongoing study confirmed real-time stability up to 12 months after production. As the NOMV had low endotoxic activity and induced high bactericidal titres in mice, they are expected to be safe and effective in humans. The production process is not limited to NonaMen and may be applicable for other N. meningitidis serogroups and other gram-negative pathogens. The current results therefore facilitate the late-stage development and clinical evaluation of NOMV vaccines.

  9. The prevalences of Neisseria gonorrhoeae and Chlamydia trachomatis infections among female sex workers in China

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    Chen Xiang-Sheng

    2013-02-01

    Full Text Available Abstract Background Sexually transmitted infections (STIs have become a major public health problem among female sex workers (FSWs in China. There have been many studies on prevalences of HIV and syphilis but the data about Neisseria gonorrhoeae (NG and Chlamydia trachomatis (CT infections are limited in this population in China. Methods A cross-sectional study was performed among FSWs recruited from different types of venues in 8 cities in China. An interview with questionnaire was conducted, followed by collection of a blood and cervical swab specimens for tests of HIV, syphilis, NG and CT infections. Results A total of 3,099 FSWs were included in the study. The overall prevalence rates of HIV, syphilis, NG and CT were 0.26%, 6.45%, 5.91% and 17.30%, respectively. Being a FSW from low-tier venue (adjusted odds ratios [AOR]=1.39 had higher risk and being age of ≥ 21 years (AOR=0.60 for 21–25 years; AOR=0.29 for 26–30 years; AOR=0.35 for 31 years or above had lower risk for CT infection; and having CT infection was significantly associated with NG infection. Conclusions The high STI prevalence rates found among FSWs, especially among FSWs in low-tier sex work venues, suggest that the comprehensive prevention and control programs including not only behavioral interventions but also screening and medical care are needed to meet the needs of this population.

  10. Olfactory nerve--a novel invasion route of Neisseria meningitidis to reach the meninges.

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    Hong Sjölinder

    Full Text Available Neisseria meningitidis is a human-specific pathogen with capacity to cause septic shock and meningitis. It has been hypothesized that invasion of the central nervous system (CNS is a complication of a bacteremic condition. In this study, we aimed to characterize the invasion route of N. meningitidis to the CNS. Using an intranasally challenged mouse disease model, we found that twenty percent of the mice developed lethal meningitis even though no bacteria could be detected in blood. Upon bacterial infection, epithelial lesions and redistribution of intracellular junction protein N-cadherin were observed at the nasal epithelial mucosa, especially at the olfactory epithelium, which is functionally and anatomically connected to the CNS. Bacteria were detected in the submucosa of the olfactory epithelium, along olfactory nerves in the cribriform plate, at the olfactory bulb and subsequently at the meninges and subarachnoid space. Furthermore, our data suggest that a threshold level of bacteremia is required for the development of meningococcal sepsis. Taken together, N. meningitidis is able to pass directly from nasopharynx to meninges through the olfactory nerve system. This study enhances our understanding how N. meningitidis invades the meninges. The nasal olfactory nerve system may be a novel target for disease prevention that can improve outcome and survival.

  11. Olfactory nerve--a novel invasion route of Neisseria meningitidis to reach the meninges.

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    Sjölinder, Hong; Jonsson, Ann-Beth

    2010-11-18

    Neisseria meningitidis is a human-specific pathogen with capacity to cause septic shock and meningitis. It has been hypothesized that invasion of the central nervous system (CNS) is a complication of a bacteremic condition. In this study, we aimed to characterize the invasion route of N. meningitidis to the CNS. Using an intranasally challenged mouse disease model, we found that twenty percent of the mice developed lethal meningitis even though no bacteria could be detected in blood. Upon bacterial infection, epithelial lesions and redistribution of intracellular junction protein N-cadherin were observed at the nasal epithelial mucosa, especially at the olfactory epithelium, which is functionally and anatomically connected to the CNS. Bacteria were detected in the submucosa of the olfactory epithelium, along olfactory nerves in the cribriform plate, at the olfactory bulb and subsequently at the meninges and subarachnoid space. Furthermore, our data suggest that a threshold level of bacteremia is required for the development of meningococcal sepsis. Taken together, N. meningitidis is able to pass directly from nasopharynx to meninges through the olfactory nerve system. This study enhances our understanding how N. meningitidis invades the meninges. The nasal olfactory nerve system may be a novel target for disease prevention that can improve outcome and survival.

  12. Olfactory Nerve—A Novel Invasion Route of Neisseria meningitidis to Reach the Meninges

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    Sjölinder, Hong; Jonsson, Ann-Beth

    2010-01-01

    Neisseria meningitidis is a human-specific pathogen with capacity to cause septic shock and meningitis. It has been hypothesized that invasion of the central nervous system (CNS) is a complication of a bacteremic condition. In this study, we aimed to characterize the invasion route of N. meningitidis to the CNS. Using an intranasally challenged mouse disease model, we found that twenty percent of the mice developed lethal meningitis even though no bacteria could be detected in blood. Upon bacterial infection, epithelial lesions and redistribution of intracellular junction protein N-cadherin were observed at the nasal epithelial mucosa, especially at the olfactory epithelium, which is functionally and anatomically connected to the CNS. Bacteria were detected in the submucosa of the olfactory epithelium, along olfactory nerves in the cribriform plate, at the olfactory bulb and subsequently at the meninges and subarachnoid space. Furthermore, our data suggest that a threshold level of bacteremia is required for the development of meningococcal sepsis. Taken together, N. meningitidis is able to pass directly from nasopharynx to meninges through the olfactory nerve system. This study enhances our understanding how N. meningitidis invades the meninges. The nasal olfactory nerve system may be a novel target for disease prevention that can improve outcome and survival. PMID:21124975

  13. An Annotated Checklist of the Human and Animal Entamoeba (Amoebida: Endamoebidae Species- A Review Article.

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    Hossein Hooshyar

    2015-06-01

    Full Text Available The number of valid of pathogen and non-pathogen species of Entamoeba has continuously increased in human and animals. This review is performed to provide an update list and some summarized information on Entamoeba species, which were identified up to the 2014.We evaluated the Entamoeba genus with a broad systematic review of the literature, books and electronic databases until February 2014. The synonyms, hosts, pathogenicity and geographical distribution of valid species were considered and recorded. Repeated and unrelated cases were excluded.Totally 51 defined species of Entamoeba were found and arranged by the number of nuclei in mature cyst according to Levin's grouping. Seven of these species within the 4 nucleate mature cysts group and 1 species with one nucleate mature cyst are pathogen. E. histolytica, E. invadence, E. rananrum and E. anatis causes lethal infection in human, reptiles, amphibians and brides respectively, four species causes non-lethal mild dysentery. The other species were non-pathogen and are important to differential diagnosis of amoebiasis.There are some unknown true species of Entamoeba that available information on the morphology, hosts, pathogenicity and distribution of them are still very limited and more considerable investigation will be needed in order to clarify the status of them.

  14. Notes from the Field: Increase in Neisseria meningitidis-Associated Urethritis Among Men at Two Sentinel Clinics - Columbus, Ohio, and Oakland County, Michigan, 2015.

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    Bazan, Jose A; Peterson, Amy S; Kirkcaldy, Robert D; Briere, Elizabeth C; Maierhofer, Courtney; Turner, Abigail Norris; Licon, Denisse B; Parker, Nicole; Dennison, Amanda; Ervin, Melissa; Johnson, Laura; Weberman, Barbara; Hackert, Pamela; Wang, Xin; Kretz, Cecilia B; Abrams, A Jeanine; Trees, David L; Del Rio, Carlos; Stephens, David S; Tzeng, Yih-Ling; DiOrio, Mary; Roberts, Mysheika Williams

    2016-06-03

    Neisseria meningitidis (Nm) urogenital infections, although less common than infections caused by Neisseria gonorrhoeae (Ng), have been associated with urethritis, cervicitis, proctitis, and pelvic inflammatory disease. Nm can appear similar to Ng on Gram stain analysis (gram-negative intracellular diplococci) (1-5). Because Nm colonizes the nasopharynx, men who receive oral sex (fellatio) can acquire urethral Nm infections (1,3,5). This report describes an increase in Nm-associated urethritis in men attending sexual health clinics in Columbus, Ohio, and Oakland County, Michigan.

  15. Molecular epidemiology and emergence of worldwide epidemic clones of Neisseria meningitidis in Taiwan

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    Chang Hsiu-Li

    2006-02-01

    Full Text Available Abstract Background Meningococcal disease is infrequently found in Taiwan, a country with 23 million people. Between 1996 and 2002, 17 to 81 clinical cases of the disease were reported annually. Reported cases dramatically increased in 2001–2002. Our record shows that only serogroup B and W135 meningococci have been isolated from patients with meningococcal disease until 2000. However, serogroup A, C and Y meningococci were detected for the first time in 2001 and continued to cause disease through 2002. Most of serogroup Y meningococcus infections localized in Central Taiwan in 2001, indicating that a small-scale outbreak of meningococcal disease had occurred. The occurrence of a meningococcal disease outbreak and the emergence of new meningococcal strains are of public health concern. Methods Neisseria meningitidis isolates from patients with meningococcal disease from 1996 to 2002 were collected and characterized by serogrouping, pulsed-field gel electrophoresis (PFGE and multilocus sequence typing (MLST. The genetic relatedness and clonal relationship between the isolates were analyzed by using the PFGE patterns and the allelic profiles of the sequence types (STs. Results Serogroups A, B, C, W135, Y, and non-serogroupable Neisseria meningitidis were, respectively, responsible for 2%, 50%, 2%, 35%, 9%, and 2% of 158 culture-confirmed cases of meningococcal disease in 1996–2002. Among 100 N. meningitidis isolates available for PFGE and MLST analyses, 51 different PFGE patterns and 30 STs were identified with discriminatory indices of 0.95 and 0.87, respectively. Of the 30 STs, 21 were newly identified and of which 19 were found in serogroup B isolates. A total of 40 PFGE patterns were identified in 52 serogroup B isolates with the patterns distributed over several distinct clusters. In contrast, the isolates within each of the serogroups A, C, W135, and Y shared high levels of PFGE pattern similarity. Analysis of the allelic profile of the

  16. Geotemporal analysis of Neisseria meningitidis clones in the United States: 2000-2005.

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    Ann E Wiringa

    Full Text Available The detection of meningococcal outbreaks relies on serogrouping and epidemiologic definitions. Advances in molecular epidemiology have improved the ability to distinguish unique Neisseria meningitidis strains, enabling the classification of isolates into clones. Around 98% of meningococcal cases in the United States are believed to be sporadic.Meningococcal isolates from 9 Active Bacterial Core surveillance sites throughout the United States from 2000 through 2005 were classified according to serogroup, multilocus sequence typing, and outer membrane protein (porA, porB, and fetA genotyping. Clones were defined as isolates that were indistinguishable according to this characterization. Case data were aggregated to the census tract level and all non-singleton clones were assessed for non-random spatial and temporal clustering using retrospective space-time analyses with a discrete Poisson probability model.Among 1,062 geocoded cases with available isolates, 438 unique clones were identified, 78 of which had ≥2 isolates. 702 cases were attributable to non-singleton clones, accounting for 66.0% of all geocoded cases. 32 statistically significant clusters comprised of 107 cases (10.1% of all geocoded cases were identified. Clusters had the following attributes: included 2 to 11 cases; 1 day to 33 months duration; radius of 0 to 61.7 km; and attack rate of 0.7 to 57.8 cases per 100,000 population. Serogroups represented among the clusters were: B (n = 12 clusters, 45 cases, C (n = 11 clusters, 27 cases, and Y (n = 9 clusters, 35 cases; 20 clusters (62.5% were caused by serogroups represented in meningococcal vaccines that are commercially available in the United States.Around 10% of meningococcal disease cases in the U.S. could be assigned to a geotemporal cluster. Molecular characterization of isolates, combined with geotemporal analysis, is a useful tool for understanding the spread of virulent meningococcal clones and patterns of

  17. Apoptosis related genes expressed in cultured Fallopian tube epithelial cells infected in vitro with Neisseria gonorrhoeae

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    PAZ A REYES

    2007-01-01

    Full Text Available Background: Infection of the Fallopian tubes (FT by Neisseria gonorrhoeae (Ngo can lead to acute salpingitis, an inflammatory condition resulting in damage primarily to the ciliated cells, with loss of ciliary activity and sloughing of the cells from the epithelium. Recently, we have shown that Ngo infection induced apoptosis in FT epithelium cells by a TNF-alpha dependent mechanism that could contribute to the cell and tissue damage observed in gonococcal salpingitis. Aim: To investigate the apoptosis-related genes expressed during apoptosis induction in cultured FT epithelial cells infected in vitro by Ngo. Materials and Methods: In the current study, we used cDNA macroarrays and real time PCR to identify and determine the expression levels of apoptosis related genes during the in vitro gonococci infection of FT epithelial cells. Results: Significant apoptosis was induced following infection with Ngo. Macroarray analysis identified the expression of multiple genes of the TNF receptor family (TNFRSF1B, -4, -6, -10A, -10B and -10D and the Bcl-2 family (BAK1, BAX, BLK, HRK and MCL-1 without differences between controls and infected cells. This lack of difference was confirmed by RT-PCR of BAX, Bcl-2, TNFRS1A (TNFR-I and TNFRSF1B (TNFR-II. Conclusion: Several genes related to apoptosis are expressed in primary cultures of epithelial cells of the human Fallopian tube. Infection with Ngo induces apoptosis without changes in the pattern of gene expression of several apoptosis-related genes. Results strongly suggest that Ngo regulates apoptosis in the FT by post-transcriptional mechanisms that need to be further addressed

  18. Deep sequencing-based analysis of the anaerobic stimulon in Neisseria gonorrhoeae

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    Clark Virginia L

    2011-01-01

    Full Text Available Abstract Background Maintenance of an anaerobic denitrification system in the obligate human pathogen, Neisseria gonorrhoeae, suggests that an anaerobic lifestyle may be important during the course of infection. Furthermore, mounting evidence suggests that reduction of host-produced nitric oxide has several immunomodulary effects on the host. However, at this point there have been no studies analyzing the complete gonococcal transcriptome response to anaerobiosis. Here we performed deep sequencing to compare the gonococcal transcriptomes of aerobically and anaerobically grown cells. Using the information derived from this sequencing, we discuss the implications of the robust transcriptional response to anaerobic growth. Results We determined that 198 chromosomal genes were differentially expressed (~10% of the genome in response to anaerobic conditions. We also observed a large induction of genes encoded within the cryptic plasmid, pJD1. Validation of RNA-seq data using translational-lacZ fusions or RT-PCR demonstrated the RNA-seq results to be very reproducible. Surprisingly, many genes of prophage origin were induced anaerobically, as well as several transcriptional regulators previously unknown to be involved in anaerobic growth. We also confirmed expression and regulation of a small RNA, likely a functional equivalent of fnrS in the Enterobacteriaceae family. We also determined that many genes found to be responsive to anaerobiosis have also been shown to be responsive to iron and/or oxidative stress. Conclusions Gonococci will be subject to many forms of environmental stress, including oxygen-limitation, during the course of infection. Here we determined that the anaerobic stimulon in gonococci was larger than previous studies would suggest. Many new targets for future research have been uncovered, and the results derived from this study may have helped to elucidate factors or mechanisms of virulence that may have otherwise been overlooked.

  19. First genome report on novel sequence types of Neisseria meningitidis: ST12777 and ST12778.

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    Veeraraghavan, Balaji; Lal, Binesh; Devanga Ragupathi, Naveen Kumar; Neeravi, Iyyan Raj; Jeyaraman, Ranjith; Varghese, Rosemol; Paul, Miracle Magdalene; Baskaran, Ashtawarthani; Ranjan, Ranjini

    2018-03-01

    Neisseria meningitidis is an important causative agent of meningitis and/or sepsis with high morbidity and mortality. Baseline genome data on N. meningitidis, especially from developing countries such as India, are lacking. This study aimed to investigate the whole genome sequences of N. meningitidis isolates from a tertiary care centre in India. Whole-genome sequencing was performed using an Ion Torrent™ Personal Genome Machine™ (PGM) with 400-bp chemistry. Data were assembled de novo using SPAdes Genome Assembler v.5.0.0.0. Sequence annotation was performed through PATRIC, RAST and the NCBI PGAAP server. Downstream analysis of the isolates was performed using the Center for Genomic Epidemiology databases for antimicrobial resistance genes and sequence types. Virulence factors and CRISPR were analysed using the PubMLST database and CRISPRFinder, respectively. This study reports the whole genome shotgun sequences of eight N. meningitidis isolates from bloodstream infections. The genome data revealed two novel sequence types (ST12777 and ST12778), along with ST11, ST437 and ST6928. The virulence profile of the isolates matched their sequence types. All isolates were negative for plasmid-mediated resistance genes. To the best of our knowledge, this is the first report of ST11 and ST437 N. meningitidis isolates in India along with two novel sequence types (ST12777 and ST12778). These results indicate that the sequence types circulating in India are diverse and require continuous monitoring. Further studies strengthening the genome data on N. meningitidis are required to understand the prevalence, spread, exact resistance and virulence mechanisms along with serotypes. Copyright © 2017 International Society for Chemotherapy of Infection and Cancer. Published by Elsevier Ltd. All rights reserved.

  20. The prevalence of Chlamydia trachomatis and Neisseria gonorrhoeae infections among men with urethritis in Kuwait.

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    Al-Sweih, N A; Khan, S; Rotimi, V O

    2011-09-01

    Chlamydial non-gonococcal urethritis and gonorrhoea are the most common sexually transmitted bacterial infections worldwide. Data on these infections are scanty in the Islamic world, especially Kuwait. The objective of this study was to establish the prevalence of Chlamydia trachomatis and Neisseria gonorrhoeae among men with symptomatic urethritis in Kuwait. Men with urethral discharge seen and managed at eight governmental hospitals were recruited into the study. A pair of urethral swab and first-voided urine sample were taken from the patients and sent immediately to the laboratory where they were processed using strand displacement nucleic acid amplification kits (SDA; ProbeTec, Becton Dickinson); one pair per patient was studied. A total of 426 symptomatic men were studied, out of whom 155 (36.4%) were infected by either C. trachomatis or N. gonorrhoeae, or both. The overall prevalence rates of C. trachomatis and N. gonorrhoeae were 12.4% and 23.9%, respectively. There was no significant difference in chlamydial and gonococcal prevalence between Kuwaiti men and non-Kuwaitis (P>0.05). Infection rates were much lower in married men than unmarried men. Men in the age range of 21-35 years were more vulnerable to both infections. The findings show that N. gonorrhoeae and, to a lesser extent, C. trachomatis are common in men with urethritis in Kuwait. Appropriate preventive strategies that conform to Islamic rules and values should be of highest priority of the policymakers. Copyright © 2011 King Saud Bin Abdulaziz University for Health Sciences. Published by Elsevier Ltd. All rights reserved.

  1. Neisseria gonorrhoeae Modulates Immunity by Polarizing Human Macrophages to a M2 Profile.

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    María Carolina Ortiz

    Full Text Available Current data suggest that Neisseria gonorrhoeae is able to suppress the protective immune response at different levels, such as B and T lymphocytes and antigen-presenting cells. The present report is focused on gonococcus evasion mechanism on macrophages (MФ and its impact in the subsequent immune response. In response to various signals MФ may undergo classical-M1 (M1-MФ or alternative-M2 (M2-MФ activation. Until now there are no reports of the gonococcus effects on human MФ polarization. We assessed the phagocytic ability of monocyte-derived MФ (MDM upon gonococcal infection by immunofluorescence and gentamicin protection experiments. Then, we evaluated cytokine profile and M1/M2 specific-surface markers on MФ challenged with N. gonorrhoeae and their proliferative effect on T cells. Our findings lead us to suggest N. gonorrhoeae stimulates a M2-MФ phenotype in which some of the M2b and none of the M1-MФ-associated markers are induced. Interestingly, N. gonorrhoeae exposure leads to upregulation of a Programmed Death Ligand 1 (PD-L1, widely known as an immunosuppressive molecule. Moreover, functional results showed that N. gonorrhoeae-treated MФ are unable to induce proliferation of human T-cells, suggesting a more likely regulatory phenotype. Taken together, our data show that N. gonorroheae interferes with MФ polarization. This study has important implications for understanding the mechanisms of clearance versus long-term persistence of N. gonorroheae infection and might be applicable for the development of new therapeutic strategies.

  2. Proteomics of Neisseria gonorrhoeae: the treasure hunt for countermeasures against an old disease

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    Benjamin I Baarda

    2015-10-01

    Full Text Available Neisseria gonorrhoeae is an exquisitely adapted, strictly human pathogen and the causative agent of the sexually transmitted infection gonorrhea. This ancient human disease remains a serious problem, occurring at high incidence globally and having a major impact on reproductive and neonatal health. N. gonorrhoeae is rapidly evolving into a superbug and no effective vaccine exists to prevent gonococcal infections. Untreated or inadequately treated gonorrhea can lead to severe sequelae, including pelvic inflammatory disease and infertility in women, epididymitis in men, and sight- threatening conjunctivitis in infants born to infected mothers. Therefore, there is an immediate need for accelerated research toward the identification of molecular targets for development of drugs with new mechanisms of action and preventive vaccine(s. Global proteomic approaches are ideally suited to guide these studies. Recent quantitative proteomics (SILAC, iTRAQ, and ICAT have illuminated the pathways utilized by N. gonorrhoeae to adapt to different lifestyles and micro-ecological niches within the host, while comparative 2D SDS-PAGE analysis has been used to elucidate spectinomycin resistance mechanisms. Further, high-throughput examinations of cell envelopes and naturally released membrane vesicles have unveiled the ubiquitous and differentially expressed proteins between temporally and geographically diverse N. gonorrhoeae isolates. This review will focus on these different approaches, emphasizing the role of proteomics in the search for vaccine candidates. Although our knowledge of N. gonorrhoeae has been expanded, still far less is known about this bacterium than the closely related N. meningitidis, where genomics- and proteomics-driven studies have led to the successful development of vaccines.

  3. Zinc piracy as a mechanism of Neisseria meningitidis for evasion of nutritional immunity.

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    Michiel Stork

    2013-10-01

    Full Text Available The outer membrane of Gram-negative bacteria functions as a permeability barrier that protects these bacteria against harmful compounds in the environment. Most nutrients pass the outer membrane by passive diffusion via pore-forming proteins known as porins. However, diffusion can only satisfy the growth requirements if the extracellular concentration of the nutrients is high. In the vertebrate host, the sequestration of essential nutrient metals is an important defense mechanism that limits the growth of invading pathogens, a process known as "nutritional immunity." The acquisition of scarce nutrients from the environment is mediated by receptors in the outer membrane in an energy-requiring process. Most characterized receptors are involved in the acquisition of iron. In this study, we characterized a hitherto unknown receptor from Neisseria meningitidis, a causative agent of sepsis and meningitis. Expression of this receptor, designated CbpA, is induced when the bacteria are grown under zinc limitation. We demonstrate that CbpA functions as a receptor for calprotectin, a protein that is massively produced by neutrophils and other cells and that has been shown to limit bacterial growth by chelating Zn²⁺ and Mn²⁺ ions. Expression of CbpA enables N. meningitidis to survive and propagate in the presence of calprotectin and to use calprotectin as a zinc source. Besides CbpA, also the TonB protein, which couples energy of the proton gradient across the inner membrane to receptor-mediated transport across the outer membrane, is required for the process. CbpA was found to be expressed in all N. meningitidis strains examined, consistent with a vital role for the protein when the bacteria reside in the host. Together, our results demonstrate that N. meningitidis is able to subvert an important defense mechanism of the human host and to utilize calprotectin to promote its growth.

  4. Prevalence of Chlamydia Trachomatis, Neisseria Gonorrhoeae, and Trichomonas Vaginalis Infection in Chilean Adolescents and Young Adults.

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    Huneeus, Andrea; Schilling, Andrea; Fernandez, Mario I

    2018-02-01

    To determine the prevalence of Chlamydia trachomatis, Neisseria gonorrhoeae, and Trichomonas vaginalis infection in sexually active Chilean adolescents and young adults. A comparative analysis was performed between genders to identify demographic, clinical, and sexual behavior characteristics to predict the occurrence of C trachomatis. Analytical observational study. Santiago, Chile. Two hundred eighty-six sexually active volunteers aged 24 years or younger (171 female and 115 male); 82.9% (237/286) of them were classified as having high socioeconomic status. Confidential survey and self-collected samples (urine for men and vaginal swabs for women). Prevalence, demographic characteristics, symptoms, and sexual behavior characteristics. The prevalence rate of C trachomatis was 8.7% (10/115) in men and 8.8% (15/171) in women (P = .58). N gonorrhoeae was detected in 1 subject, whereas no T vaginalis cases were detected. In multivariate analysis, having some college education was protective (odds ratio [OR], 0.28; 95% confidence interval [CI], 0.09-0.89), whereas having a higher number of sexual partners was a risk factor (OR, 1.19; 95% CI, 1.1-1.3) for C trachomatis infection. The latter was also predicted by postcoital bleeding (OR, 4.6; 95% CI, 1.30-16.23) in the female model. C trachomatis infection rates were similar between both genders. Protective characteristics for the occurrence of this infection were having some college education, lower number of sexual partners, and if female, the absence of postcoital bleeding. This study highlights the importance of C trachomatis screening among the Chilean affluent population younger than 25 years. However, further studies are needed in a more diverse and representative sample to recommend universal screening in Chilean adolescents and young adults. Copyright © 2018 North American Society for Pediatric and Adolescent Gynecology. Published by Elsevier Inc. All rights reserved.

  5. Outer membrane biogenesis in Escherichia coli, Neisseria meningitidis, and Helicobacter pylori: paradigm deviations in H. pylori.

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    Liechti, George; Goldberg, Joanna B

    2012-01-01

    The bacterial pathogen Helicobacter pylori is capable of colonizing the gastric mucosa of the human stomach using a variety of factors associated with or secreted from its outer membrane (OM). Lipopolysaccharide (LPS) and numerous OM proteins have been shown to be involved in adhesion and immune stimulation/evasion. Many of these factors are essential for colonization and/or pathogenesis in a variety of animal models. Despite this wide array of potential targets present on the bacterial surface, the ability of H. pylori to vary its OM profile limits the effectiveness of vaccines or therapeutics that target any single one of these components. However, it has become evident that the proteins comprising the complexes that transport the majority of these molecules to the OM are highly conserved and often essential. The field of membrane biogenesis has progressed remarkably in the last few years, and the possibility now exists for targeting the mechanisms by which β-barrel proteins, lipoproteins, and LPS are transported to the OM, resulting in loss of bacterial fitness and significant altering of membrane permeability. In this review, the OM transport machinery for LPS, lipoproteins, and outer membrane proteins (OMPs) are discussed. While the principal investigations of these transport mechanisms have been conducted in Escherichia coli and Neisseria meningitidis, here these systems will be presented in the genetic context of ε proteobacteria. Bioinformatic analysis reveals that minimalist genomes, such as that of Helicobacter pylori, offer insight into the smallest number of components required for these essential pathways to function. Interestingly, in the majority of ε proteobacteria, while the inner and OM associated apparatus of LPS, lipoprotein, and OMP transport pathways appear to all be intact, most of the components associated with the periplasmic compartment are either missing or are almost unrecognizable when compared to their E. coli counterparts. Eventual

  6. Neisseria gonorrhoeae molecular typing for understanding sexual networks and antimicrobial resistance transmission: A systematic review.

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    Town, Katy; Bolt, Hikaru; Croxford, Sara; Cole, Michelle; Harris, Simon; Field, Nigel; Hughes, Gwenda

    2018-06-01

    Neisseria gonorrhoeae (NG) is a significant global public health concern due to rising diagnoses rates and antimicrobial resistance. Molecular combined with epidemiological data have been used to understand the distribution and spread of NG, as well as relationships between cases in sexual networks, but the public health value gained from these studies is unclear. We conducted a systematic review to examine how molecular epidemiological studies have informed understanding of sexual networks and NG transmission, and subsequent public health interventions. Five research databases were systematically searched up to 31st March 2017 for studies that used sequence-based DNA typing methods, including whole genome sequencing, and linked molecular data to patient-level epidemiological data. Data were extracted and summarised to identify common themes. Of the 49 studies included, 82% used NG Multi-antigen Sequence Typing. Gender and sexual orientation were commonly used to characterise sexual networks that were inferred using molecular clusters; clusters predominantly of one patient group often contained a small number of isolates from other patient groups. Suggested public health applications included using these data to target interventions at specific populations, confirm outbreaks, and inform partner management, but these were mainly untested. Combining molecular and epidemiological data has provided insight into sexual mixing patterns, and dissemination of NG, but few studies have applied these findings to design or evaluate public health interventions. Future studies should focus on the application of molecular epidemiology in public health practice to provide evidence for how to prevent and control NG. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

  7. Extragenital Infections Caused by Chlamydia trachomatis and Neisseria gonorrhoeae: A Review of the Literature

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    Philip A. Chan

    2016-01-01

    Full Text Available In the United States, sexually transmitted diseases due to Chlamydia trachomatis and Neisseria gonorrhoeae continue to be a major public health burden. Screening of extragenital sites including the oropharynx and rectum is an emerging practice based on recent studies highlighting the prevalence of infection at these sites. We reviewed studies reporting the prevalence of extragenital infections in women, men who have sex with men (MSM, and men who have sex only with women (MSW, including distribution by anatomical site. Among women, prevalence was found to be 0.6–35.8% for rectal gonorrhea (median reported prevalence 1.9%, 0–29.6% for pharyngeal gonorrhea (median 2.1%, 2.0–77.3% for rectal chlamydia (median 8.7%, and 0.2–3.2% for pharyngeal chlamydia (median 1.7%. Among MSM, prevalence was found to be 0.2–24.0% for rectal gonorrhea (median 5.9%, 0.5–16.5% for pharyngeal gonorrhea (median 4.6%, 2.1–23.0% for rectal chlamydia (median 8.9%, and 0–3.6% for pharyngeal chlamydia (median 1.7%. Among MSW, the prevalence was found to be 0–5.7% for rectal gonorrhea (median 3.4%, 0.4–15.5% for pharyngeal gonorrhea (median 2.2%, 0–11.8% for rectal chlamydia (median 7.7%, and 0–22.0% for pharyngeal chlamydia (median 1.6%. Extragenital infections are often asymptomatic and found in the absence of reported risk behaviors, such as receptive anal and oral intercourse. We discuss current clinical recommendations and future directions for research.

  8. Expression capable library for studies of Neisseria gonorrhoeae, version 1.0

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    Wachocki Susi

    2005-09-01

    Full Text Available Abstract Background The sexually transmitted disease, gonorrhea, is a serious health problem in developed as well as in developing countries, for which treatment continues to be a challenge. The recent completion of the genome sequence of the causative agent, Neisseria gonorrhoeae, opens up an entirely new set of approaches for studying this organism and the diseases it causes. Here, we describe the initial phases of the construction of an expression-capable clone set representing the protein-coding ORFs of the gonococcal genome using a recombination-based cloning system. Results The clone set thus far includes 1672 of the 2250 predicted ORFs of the N. gonorrhoeae genome, of which 1393 (83% are sequence-validated. Included in this set are 48 of the 61 ORFs of the gonococcal genetic island of strain MS11, not present in the sequenced genome of strain FA1090. L-arabinose-inducible glutathione-S-transferase (GST-fusions were constructed from random clones and each was shown to express a fusion protein of the predicted size following induction, demonstrating the use of the recombination cloning system. PCR amplicons of each ORF used in the cloning reactions were spotted onto glass slides to produce DNA microarrays representing 2035 genes of the gonococcal genome. Pilot experiments indicate that these arrays are suitable for the analysis of global gene expression in gonococci. Conclusion This archived set of Gateway® entry clones will facilitate high-throughput genomic and proteomic studies of gonococcal genes using a variety of expression and analysis systems. In addition, the DNA arrays produced will allow us to generate gene expression profiles of gonococci grown in a wide variety of conditions. Together, the resources produced in this work will facilitate experiments to dissect the molecular mechanisms of gonococcal pathogenesis on a global scale, and ultimately lead to the determination of the functions of unknown genes in the genome.

  9. Deep sequencing whole transcriptome exploration of the σE regulon in Neisseria meningitidis.

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    Robert Antonius Gerhardus Huis in 't Veld

    Full Text Available Bacteria live in an ever-changing environment and must alter protein expression promptly to adapt to these changes and survive. Specific response genes that are regulated by a subset of alternative σ(70-like transcription factors have evolved in order to respond to this changing environment. Recently, we have described the existence of a σ(E regulon including the anti-σ-factor MseR in the obligate human bacterial pathogen Neisseria meningitidis. To unravel the complete σ(E regulon in N. meningitidis, we sequenced total RNA transcriptional content of wild type meningococci and compared it with that of mseR mutant cells (ΔmseR in which σ(E is highly expressed. Eleven coding genes and one non-coding gene were found to be differentially expressed between H44/76 wildtype and H44/76ΔmseR cells. Five of the 6 genes of the σ(E operon, msrA/msrB, and the gene encoding a pepSY-associated TM helix family protein showed enhanced transcription, whilst aniA encoding a nitrite reductase and nspA encoding the vaccine candidate Neisserial surface protein A showed decreased transcription. Analysis of differential expression in IGRs showed enhanced transcription of a non-coding RNA molecule, identifying a σ(E dependent small non-coding RNA. Together this constitutes the first complete exploration of an alternative σ-factor regulon in N. meningitidis. The results direct to a relatively small regulon indicative for a strictly defined response consistent with a relatively stable niche, the human throat, where N. meningitidis resides.

  10. In vivo adaptation and persistence of Neisseria meningitidis within the nasopharyngeal mucosa.

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    Kay O Johswich

    Full Text Available Neisseria meningitidis (Nme asymptomatically colonizes the human nasopharynx, yet can initiate rapidly-progressing sepsis and meningitis in rare instances. Understanding the meningococcal lifestyle within the nasopharyngeal mucosa, a phase of infection that is prerequisite for disease, has been hampered by the lack of animal models. Herein, we compare mice expressing the four different human carcinoembryonic antigen-related cell adhesion molecules (CEACAMs that can bind the neisserial Opa protein adhesins, and find that expression of human CEACAM1 is necessary and sufficient to establish intranasal colonization. During infection, in vivo selection for phase variants expressing CEACAM1-specific Opa proteins occurs, allowing mucosal attachment and entry into the subepithelial space. Consistent with an essential role for Opa proteins in this process, Opa-deficient meningococci were unable to colonize the CEACAM1-humanized mice. While simple Opa-mediated attachment triggered an innate response regardless of meningococcal viability within the inoculum, persistence of viable Opa-expressing bacteria within the CEACAM1-humanized mice was required for a protective memory response to be achieved. Parenteral immunization with a capsule-based conjugate vaccine led to the accumulation of protective levels of Nme-specific IgG within the nasal mucus, yet the sterilizing immunity afforded by natural colonization was instead conferred by Nme-specific IgA without detectable IgG. Considered together, this study establishes that the availability of CEACAM1 helps define the exquisite host specificity of this human-restricted pathogen, displays a striking example of in vivo selection for the expression of desirable Opa variants, and provides a novel model in which to consider meningococcal infection and immunity within the nasopharyngeal mucosa.

  11. Virulence evolution of the human pathogen Neisseria meningitidis by recombination in the core and accessory genome.

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    Biju Joseph

    Full Text Available BACKGROUND: Neisseria meningitidis is a naturally transformable, facultative pathogen colonizing the human nasopharynx. Here, we analyze on a genome-wide level the impact of recombination on gene-complement diversity and virulence evolution in N. meningitidis. We combined comparative genome hybridization using microarrays (mCGH and multilocus sequence typing (MLST of 29 meningococcal isolates with computational comparison of a subset of seven meningococcal genome sequences. PRINCIPAL FINDINGS: We found that lateral gene transfer of minimal mobile elements as well as prophages are major forces shaping meningococcal population structure. Extensive gene content comparison revealed novel associations of virulence with genetic elements besides the recently discovered meningococcal disease associated (MDA island. In particular, we identified an association of virulence with a recently described canonical genomic island termed IHT-E and a differential distribution of genes encoding RTX toxin- and two-partner secretion systems among hyperinvasive and non-hyperinvasive lineages. By computationally screening also the core genome for signs of recombination, we provided evidence that about 40% of the meningococcal core genes are affected by recombination primarily within metabolic genes as well as genes involved in DNA replication and repair. By comparison with the results of previous mCGH studies, our data indicated that genetic structuring as revealed by mCGH is stable over time and highly similar for isolates from different geographic origins. CONCLUSIONS: Recombination comprising lateral transfer of entire genes as well as homologous intragenic recombination has a profound impact on meningococcal population structure and genome composition. Our data support the hypothesis that meningococcal virulence is polygenic in nature and that differences in metabolism might contribute to virulence.

  12. Antimicrobial resistance in Neisseria gonorrhoeae in China: a meta-analysis.

    Science.gov (United States)

    Chen, Yawen; Gong, Yanhong; Yang, Tingting; Song, Xingyue; Li, Jing; Gan, Yong; Yin, Xiaoxv; Lu, Zuxun

    2016-03-03

    Neisseria gonorrhoeae (N. gonorrhoeae) resistance to antimicrobial has been a major concern in China, and epidemiological data on N. gonorrhoeae resistance are not well understood. This meta-analysis was aimed at summarizing the evidence on N. gonorrhoeae resistance to penicillin, tetracycline, ciprofloxacin, ceftriaxone and spectinomycin in China. Two researchers independently searched five databases to identify studies on N. gonorrhoeae resistance to antimicrobials from the databases' inception to November 7, 2014. A random-effects model was used to estimate the antimicrobial resistance rates and their corresponding 95% confidence intervals (CIs). Publication bias was assessed with the Begg rank correlation test and the Egger test. We included 127 studies in our synthesis reporting antimicrobial resistance. Our analyses demonstrated that N. gonorrhoeae resistance to penicillin and tetracycline respectively increased from 74.41% (95% CI: 64.1-84.7%) and 68.3% (95% CI: 58.7-78.0%) in 2000 to 84.2% (95% CI: 79.7-88.8%) and 82.4% (95% CI: 79.9-84.7%) in 2012. N. gonorrhoeae resistance to ciprofloxacin experienced a steady increase from 12.7% (95% CI, 8.6-16.7%) in 1995 and reached 93.8% (95% CI: 91.9-95.7%) in 2003. N. gonorrhoeae resistance to ceftriaxone was 1.7% (95% CI: 0.5-5.7%) before 1995 and 0.5% (95% CI: 0.2-1.4%) in 2012, and N. gonorrhoeae resistance to spectinomycin was less than 2% from 1995 to 2012. N. gonorrhoeae resistance rates to penicillin, tetracycline and ciprofloxacin were high in China. Ceftriaxone and spectinomycin remained effective therapy for the treatment of gonorrhea. It is essential to strengthen N. gonorrhoeae resistance surveillance and update treatment guidelines timely.

  13. Host iron binding proteins acting as niche indicators for Neisseria meningitidis.

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    Philip W Jordan

    Full Text Available Neisseria meningitidis requires iron, and in the absence of iron alters its gene expression to increase iron acquisition and to make the best use of the iron it has. During different stages of colonization and infection available iron sources differ, particularly the host iron-binding proteins haemoglobin, transferrin, and lactoferrin. This study compared the transcriptional responses of N. meningitidis, when grown in the presence of these iron donors and ferric iron, using microarrays.Specific transcriptional responses to the different iron sources were observed, including genes that are not part of the response to iron restriction. Comparisons between growth on haemoglobin and either transferrin or lactoferrin identified changes in 124 and 114 genes, respectively, and 33 genes differed between growth on transferrin or lactoferrin. Comparison of gene expression from growth on haemoglobin or ferric iron showed that transcription is also affected by the entry of either haem or ferric iron into the cytoplasm. This is consistent with a model in which N. meningitidis uses the relative availability of host iron donor proteins as niche indicators.Growth in the presence of haemoglobin is associated with a response likely to be adaptive to survival within the bloodstream, which is supported by serum killing assays that indicate growth on haemoglobin significantly increases survival, and the response to lactoferrin is associated with increased expression of epithelial cell adhesins and oxidative stress response molecules. The transferrin receptor is the most highly transcribed receptor and has the fewest genes specifically induced in its presence, suggesting this is the favoured iron source for the bacterium. Most strikingly, the responses to haemoglobin, which is associated with unrestricted growth, indicates a low iron transcriptional profile, associated with an aggressive phenotype that may be adaptive to access host iron sources but which may also

  14. Comparing the disk-diffusion and agar dilution tests for Neisseria gonorrhoeae antimicrobial susceptibility testing

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    Hsi Liu

    2016-11-01

    Full Text Available Abstract Background We assessed the validity of testing for antimicrobial susceptibility of clinical and mutant Neisseria gonorrhoeae (GC isolates by disk diffusion in comparison to agar dilution, and Etest® (bioMerieux, France, respectively, for three third generation extended spectrum cephalosporins (ESC: ceftriaxone (CRO, cefixime (CFX, and cefpodoxime (CPD. Methods One hundred and five clinical isolates and ten laboratory-mutants were tested following Clinical Laboratory Standard Institute (CLSI and manufacturer’s standards for each of the three methods. The measured diameters by the disk diffusion method were tested for correlation with the MIC values by agar dilution. In addition, comparisons with the Etest® were made. Categorical results for concordance, based on standard CLSI cutoffs, between the disk diffusion and the other two methods, respectively, were tested using the Chi-square statistics. Reproducibility was tested for CFX across a 6-month interval by repeated disk tests. Results Across all 115 specimens, the disk diffusion tests produced good categorical agreements, exhibiting concordance of 93.1%, 92.1%, and 90.4% with agar dilution and 93.0%, 92.1%, and 90.4% with Etest®, for CRO, CFX, and CPD, respectively. Pearson correlations between disk-diffusion diameters and agar dilution MIC’s were -0.59, -0.67, and -0.81 for CRO, CFX, and CPD, respectively. The correlations between disk diffusion and Etest® were -0.58, -0.73, and -0.49. Pearson correlation between the CFX disk readings over a 6-month interval was 91%. Conclusions Disk diffusion tests remain to be a useful, reliable and fast screening method for qualitative antimicrobial susceptibility testing for ceftriaxone, cefixime, and cefpodoxime.

  15. A virulence-associated filamentous bacteriophage of Neisseria meningitidis increases host-cell colonisation.

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    Emmanuelle Bille

    2017-07-01

    Full Text Available Neisseria meningitidis is a commensal of human nasopharynx. In some circumstances, this bacteria can invade the bloodstream and, after crossing the blood brain barrier, the meninges. A filamentous phage, designated MDAΦ for Meningococcal Disease Associated, has been associated with invasive disease. In this work we show that the prophage is not associated with a higher virulence during the bloodstream phase of the disease. However, looking at the interaction of N. meningitidis with epithelial cells, a step essential for colonization of the nasopharynx, we demonstrate that the presence of the prophage, via the production of viruses, increases colonization of encapsulated meningococci onto monolayers of epithelial cells. The analysis of the biomass covering the epithelial cells revealed that meningococci are bound to the apical surface of host cells by few layers of heavily piliated bacteria, whereas, in the upper layers, bacteria are non-piliated but surrounded by phage particles which (i form bundles of filaments, and/or (ii are in some places associated with bacteria. The latter are likely to correspond to growing bacteriophages during their extrusion through the outer membrane. These data suggest that, as the biomass increases, the loss of piliation in the upper layers of the biomass does not allow type IV pilus bacterial aggregation, but is compensated by a large production of phage particles that promote bacterial aggregation via the formation of bundles of phage filaments linked to the bacterial cell walls. We propose that MDAΦ by increasing bacterial colonization in the mucosa at the site-of-entry, increase the occurrence of diseases.

  16. Preliminary crystallographic data of the three homologues of the thiol–disulfide oxidoreductase DsbA in Neisseria meningitidis

    Energy Technology Data Exchange (ETDEWEB)

    Lafaye, Céline [Laboratoire des Protéines Membranaires, Institut de Biologie Structurale, CEA/CNRS/Université Joseph Fourier, 41 Rue Jules Horowitz, 38027 Grenoble CEDEX 01 (France); Iwena, Thomas; Ferrer, Jean-Luc [Laboratoire de Cristallogénèse et Cristallisation des Protéines, Institut de Biologie Structurale, CEA/CNRS/Université Joseph Fourier, 41 Rue Jules Horowitz, 38027 Grenoble CEDEX 01 (France); Kroll, J. Simon [Department of Paediatrics, Imperial College London, St Mary’s Hospital Campus, Norfolk Place, London W2 1PG (United Kingdom); Griat, Mickael; Serre, Laurence, E-mail: laurence.serre@ibs.fr [Laboratoire des Protéines Membranaires, Institut de Biologie Structurale, CEA/CNRS/Université Joseph Fourier, 41 Rue Jules Horowitz, 38027 Grenoble CEDEX 01 (France)

    2008-02-01

    The Neisseria meningitidis genome possesses three genes encoding active DsbAs. To throw light on the reason for this genetic multiplicity, the three enzymes have been purified and crystallized. Bacterial virulence depends on the correct folding of surface-exposed proteins, a process that is catalyzed by the thiol-disulfide oxidoreductase DsbA, which facilitates the synthesis of disulfide bonds in Gram-negative bacteria. Uniquely among bacteria, the Neisseria meningitidis genome possesses three genes encoding active DsbAs: DsbA1, DsbA2 and DsbA3. DsbA1 and DsbA2 have been characterized as lipoproteins involved in natural competence and in host-interactive biology, while the function of DsbA3 remains unknown. In an attempt to shed light on the reason for this multiplicity of dsbA genes, the three enzymes from N. meningitidis have been purified and crystallized in the presence of high concentrations of ammonium sulfate. The best crystals were obtained using DsbA1 and DsbA3; they belong to the orthorhombic and tetragonal systems and diffract to 1.5 and 2.7 Å resolution, respectively.

  17. Structure of the P{sub II} signal transduction protein of Neisseria meningitidis at 1.85 Å resolution

    Energy Technology Data Exchange (ETDEWEB)

    Nichols, Charles E. [Division of Structural Biology, Henry Wellcome Building for Genomic Medicine, University of Oxford, Roosevelt Drive, Oxford OX3 7BN (United Kingdom); Sainsbury, Sarah; Berrow, Nick S.; Alderton, David [The Oxford Protein Production Facility, Henry Wellcome Building for Genomic Medicine, University of Oxford, Roosevelt Drive, Oxford OX3 7BN (United Kingdom); Saunders, Nigel J. [The Bacterial Pathogenesis and Functional Genomics Group, The Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE (United Kingdom); Stammers, David K. [Division of Structural Biology, Henry Wellcome Building for Genomic Medicine, University of Oxford, Roosevelt Drive, Oxford OX3 7BN (United Kingdom); The Oxford Protein Production Facility, Henry Wellcome Building for Genomic Medicine, University of Oxford, Roosevelt Drive, Oxford OX3 7BN (United Kingdom); Owens, Raymond J., E-mail: ray@strubi.ox.ac.uk [The Oxford Protein Production Facility, Henry Wellcome Building for Genomic Medicine, University of Oxford, Roosevelt Drive, Oxford OX3 7BN (United Kingdom); Division of Structural Biology, Henry Wellcome Building for Genomic Medicine, University of Oxford, Roosevelt Drive, Oxford OX3 7BN (United Kingdom)

    2006-06-01

    The structure of the P{sub II} signal transduction protein of N. meningitidis at 1.85 Å resolution is described. The P{sub II} signal transduction proteins GlnB and GlnK are implicated in the regulation of nitrogen assimilation in Escherichia coli and other enteric bacteria. P{sub II}-like proteins are widely distributed in bacteria, archaea and plants. In contrast to other bacteria, Neisseria are limited to a single P{sub II} protein (NMB 1995), which shows a high level of sequence identity to GlnB and GlnK from Escherichia coli (73 and 62%, respectively). The structure of the P{sub II} protein from N. meningitidis (serotype B) has been solved by molecular replacement to a resolution of 1.85 Å. Comparison of the structure with those of other P{sub II} proteins shows that the overall fold is tightly conserved across the whole population of related proteins, in particular the positions of the residues implicated in ATP binding. It is proposed that the Neisseria P{sub II} protein shares functions with GlnB/GlnK of enteric bacteria.

  18. The tomato wilt fungus Fusarium oxysporum f. sp. lycopersici shares common ancestors with nonpathogenic F. oxysporum isolated from wild tomatoes in the Peruvian Andes.

    Science.gov (United States)

    Inami, Keigo; Kashiwa, Takeshi; Kawabe, Masato; Onokubo-Okabe, Akiko; Ishikawa, Nobuko; Pérez, Enrique Rodríguez; Hozumi, Takuo; Caballero, Liliana Aragón; de Baldarrago, Fatima Cáceres; Roco, Mauricio Jiménez; Madadi, Khalid A; Peever, Tobin L; Teraoka, Tohru; Kodama, Motoichiro; Arie, Tsutomu

    2014-01-01

    Fusarium oxysporum is an ascomycetous fungus that is well-known as a soilborne plant pathogen. In addition, a large population of nonpathogenic F. oxysporum (NPF) inhabits various environmental niches, including the phytosphere. To obtain an insight into the origin of plant pathogenic F. oxysporum, we focused on the tomato (Solanum lycopersicum) and its pathogenic F. oxysporum f. sp. lycopersici (FOL). We collected F. oxysporum from wild and transition Solanum spp. and modern cultivars of tomato in Chile, Ecuador, Peru, Mexico, Afghanistan, Italy, and Japan, evaluated the fungal isolates for pathogenicity, VCG, mating type, and distribution of SIX genes related to the pathogenicity of FOL, and constructed phylogenies based on ribosomal DNA intergenic spacer sequences. All F. oxysporum isolates sampled were genetically more diverse than FOL. They were not pathogenic to the tomato and did not carry SIX genes. Certain NPF isolates including those from wild Solanum spp. in Peru were grouped in FOL clades, whereas most of the NPF isolates were not. Our results suggested that the population of NPF isolates in FOL clades gave rise to FOL by gaining pathogenicity.

  19. Host plant-dependent phenotypic reversion of Ralstonia solanacearum from non-pathogenic to pathogenic forms via alterations in the phcA gene.

    Science.gov (United States)

    Poussier, Stéphane; Thoquet, Philippe; Trigalet-Demery, Danièle; Barthet, Séverine; Meyer, Damien; Arlat, Matthieu; Trigalet, André

    2003-08-01

    Ralstonia solanacearum is a plant pathogenic bacterium that undergoes a spontaneous phenotypic conversion (PC) from a wild-type pathogenic to a non-pathogenic form. PC is often associated with mutations in phcA, which is a key virulence regulatory gene. Until now, reversion to the wild-type pathogenic form has not been observed for PC variants and the biological significance of PC has been questioned. In this study, we characterized various alterations in phcA (eight IS element insertions, three tandem duplications, seven deletions and a base substitution) in 19 PC mutants from the model strain GMI1000. In five of these variants, reversion to the pathogenic form was observed in planta, while no reversion was ever noticed in vitro whatever culture media used. However, reversion was observed for a 64 bp tandem duplication in vitro in the presence of tomato root exudate. This is the first report showing a complete cycle of phenotypic conversion/reversion in a plant pathogenic bacterium.

  20. A Novel Mechanism of High-Level, Broad-Spectrum Antibiotic Resistance Caused by a Single Base Pair Change in Neisseria gonorrhoeae

    Science.gov (United States)

    2011-09-20

    respect, Eisenstein and Sparling noted that a single base pair deletion in the inverted repeat in the mtrR promoter, a mutation which also confers high...Regulation of the MtrC-MtrD-MtrE efflux-pump system modulates the in vivo fitness of Neisseria gonorrhoeae. J. Infect. Dis. 196:1804 –1812. 21. Eisenstein BI

  1. Meningococcal disease in The Netherlands, 1958-1990: a steady increase in the incidence since 1982 partially caused by new serotypes and subtypes of Neisseria meningitidis

    NARCIS (Netherlands)

    Scholten, R. J.; Bijlmer, H. A.; Poolman, J. T.; Kuipers, B.; Caugant, D. A.; van Alphen, L.; Dankert, J.; Valkenburg, H. A.

    1993-01-01

    In order to explain a threefold increase in the incidence of meningococcal disease in the Netherlands during the 1980s, we serotyped and subtyped Neisseria meningitidis isolates recovered between 1958 and 1990 from > 3,000 patients with systemic disease. No single strain could be held responsible

  2. Multiple-locus variable-number tandem repeat analysis of Neisseria meningitidis yields groupings similar to those obtained by multilocus sequence typing.

    NARCIS (Netherlands)

    Schouls, Leo M; Ende, Arie van der; Damen, Marjolein; Pol, Ingrid van de

    2006-01-01

    We identified many variable-number tandem repeat (VNTR) loci in the genomes of Neisseria meningitidis serogroups A, B, and C and utilized a number of these loci to develop a multiple-locus variable-number tandem repeat analysis (MLVA). Eighty-five N. meningitidis serogroup B and C isolates obtained

  3. IgA1 antibodies specific for outer membrane protein PorA modulate the interaction between Neisseria meningitidis and the epithelium

    NARCIS (Netherlands)

    Horton, R. E.; Vidarsson, G.; Virji, M.; Williams, N. A.; Heyderman, R. S.

    2009-01-01

    Despite high carriage rates of Neisseria meningitidis, incidence of meningococcal disease remains low, partially due to development of natural immunity. We have previously demonstrated an inverse relationship between salivary anti-meningococcal IgA and disease incidence, but little is known about

  4. Necrotising fasciitis as atypical presentation of infection with emerging Neisseria meningitidis serogroup W (MenW) clonal complex 11, the Netherlands, March 2017

    NARCIS (Netherlands)

    Russcher, Anne; Fanoy, Ewout; van Olden, Ger D. J.; Graafland, Antonie D.; van der Ende, Arie; Knol, Mirjam J.

    2017-01-01

    In March 2017, a patient with necrotising fasciitis caused by Neisseria meningitidis serogroup W (MenW) clonal complex 11 was diagnosed in the Netherlands. Unusual and severe presentations of MenW infections are common in the current European epidemic. In the Netherlands, the incidence of MenW

  5. Interlaboratory comparison of agar dilution and Etest methods for determining the MICs of antibiotics used in management of Neisseria meningitidis infections

    NARCIS (Netherlands)

    Vázquez, Julio A.; Arreaza, Luisa; Block, Colin; Ehrhard, Ingrid; Gray, Stephen J.; Heuberger, Sigrid; Hoffmann, Steen; Kriz, Paula; Nicolas, Pierre; Olcen, Per; Skoczynska, Anna; Spanjaard, Lodewijk; Stefanelli, Paola; Taha, Muhamed-Kheir; Tzanakaki, Georgina

    2003-01-01

    Previous studies have shown that there is considerable variation in the methods and media used to determine the susceptibility of Neisseria meningitidis to antimicrobial agents in different countries. In this study, national and regional reference laboratories used a standardized methodology to

  6. The monomeric form of Neisseria DNA mimic protein DMP19 prevents DNA from binding to the histone-like HU protein

    Science.gov (United States)

    Ko, Tzu-Ping; Liao, Yi-Ting; Hsu, Kai-Cheng

    2017-01-01

    DNA mimicry is a direct and effective strategy by which the mimic competes with DNA for the DNA binding sites on other proteins. Until now, only about a dozen proteins have been shown to function via this strategy, including the DNA mimic protein DMP19 from Neisseria meningitides. We have shown previously that DMP19 dimer prevents the operator DNA from binding to the transcription factor NHTF. Here, we provide new evidence that DMP19 monomer can also interact with the Neisseria nucleoid-associated protein HU. Using BS3 crosslinking, gel filtration and isothermal titration calorimetry assays, we found that DMP19 uses its monomeric form to interact with the Neisseria HU dimer. Crosslinking conjugated mass spectrometry was used to investigate the binding mode of DMP19 monomer and HU dimer. Finally, an electrophoretic mobility shift assay (EMSA) confirmed that the DNA binding affinity of HU is affected by DMP19. These results showed that DMP19 is bifunctional in the gene regulation of Neisseria through its variable oligomeric forms. PMID:29220372

  7. Behavioural, emotional, and post-traumatic stress problems in children and adolescents, long term after septic shock caused by Neisseria meningitidis

    NARCIS (Netherlands)

    Vermunt, L. C. A. C.; Buysse, C. M. P.; Joosten, K. F. M.; Hazelzet, J. A.; Verhulst, F. C.; Utens, E. M. W. J.

    2008-01-01

    To assess the occurrence of a wide range of behavioural, emotional, and post-traumatic stress problems in children and adolescents, long term after septic shock caused by Neisseria meningitidis (MSS). This study included 6- to 17-year-old patients who survived MSS and were admitted to the PICU of

  8. Comparative innate immune interactions of human and bovine secretory IgA with pathogenic and non-pathogenic bacteria.

    Science.gov (United States)

    Hodgkinson, Alison J; Cakebread, Julie; Callaghan, Megan; Harris, Paul; Brunt, Rachel; Anderson, Rachel C; Armstrong, Kelly M; Haigh, Brendan

    2017-03-01

    Secretory IgA (SIgA) from milk contributes to early colonization and maintenance of commensal/symbiotic bacteria in the gut, as well as providing defence against pathogens. SIgA binds bacteria using specific antigenic sites or non-specifically via its glycans attached to α-heavy-chain and secretory component. In our study, we tested the hypothesis that human and bovine SIgA have similar innate-binding activity for bacteria. SIgAs, isolated from human and bovine milk, were incubated with a selection of commensal, pathogenic and probiotic bacteria. Using flow cytometry, we measured numbers of bacteria binding SIgA and their level of SIgA binding. The percentage of bacteria bound by human and bovine SIgA varied from 30 to 90% depending on bacterial species and strains, but was remarkably consistent between human and bovine SIgA. The level of SIgA binding per bacterial cell was lower for those bacteria that had a higher percentage of SIgA-bound bacteria, and higher for those bacteria that had lower percentage of SIgA-bound bacteria. Overall, human and bovine SIgA interacted with bacteria in a comparable way. This contributes to longer term research about the potential benefits of bovine SIgA for human consumers. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Efficacy of a Blend of Sulfuric Acid and Sodium Sulfate against Shiga Toxin-Producing Escherichia coli, Salmonella, and Nonpathogenic Escherichia coli Biotype I on Inoculated Prerigor Beef Surface Tissue.

    Science.gov (United States)

    Scott-Bullard, Britteny R; Geornaras, Ifigenia; Delmore, Robert J; Woerner, Dale R; Reagan, James O; Morgan, J Bred; Belk, Keith E

    2017-12-01

    A study was conducted to investigate the efficacy of a sulfuric acid-sodium sulfate blend (SSS) against Escherichia coli O157:H7, non-O157 Shiga toxin-producing E. coli (STEC), Salmonella, and nonpathogenic E. coli biotype I on prerigor beef surface tissue. The suitability of using the nonpathogenic E. coli as a surrogate for in-plant validation studies was also determined by comparing the data obtained for the nonpathogenic inoculum with those for the pathogenic inocula. Prerigor beef tissue samples (10 by 10 cm) were inoculated (ca. 6 log CFU/cm 2 ) on the adipose side in a laboratory-scale spray cabinet with multistrain mixtures of E. coli O157:H7 (5 strains), non-O157 STEC (12 strains), Salmonella (6 strains), or E. coli biotype I (5 strains). Treatment parameters evaluated were two SSS pH values (1.5 and 1.0) and two spray application pressures (13 and 22 lb/in 2 ). Untreated inoculated beef tissue samples served as controls for initial bacterial populations. Overall, the SSS treatments lowered inoculated (6.1 to 6.4 log CFU/cm 2 ) bacterial populations by 0.6 to 1.5 log CFU/cm 2 (P SSS was applied to samples inoculated with any of the tested E. coli inocula; however, solution pH did have a significant effect (P SSS was applied to samples inoculated with Salmonella. Results indicated that the response of the nonpathogenic E. coli inoculum to the SSS treatments was similar (P ≥ 0.05) to that of the pathogenic inocula tested, making the E. coli biotype I strains viable surrogate organisms for in-plant validation of SSS efficacy on beef. The application of SSS at the tested parameters to prerigor beef surface tissue may be an effective intervention for controlling pathogens in a commercial beef harvest process.

  10. Pathogenicity of Human ST23 Streptococcus agalactiae to Fish and Genomic Comparison of Pathogenic and Non-pathogenic Isolates

    Directory of Open Access Journals (Sweden)

    Rui Wang

    2017-10-01

    Full Text Available Streptococcus agalactiae, or Group B Streptococcus (GBS, is a major pathogen causing neonatal sepsis and meningitis, bovine mastitis, and fish meningoencephalitis. CC23, including its namesake ST23, is not only the predominant GBS strain derived from human and cattle, but also can infect a variety of homeothermic and poikilothermic species. However, it has never been characterized in fish. This study aimed to determine the pathogenicity of ST23 GBS to fish and explore the mechanisms causing the difference in the pathogenicity of ST23 GBS based on the genome analysis. Infection of tilapia with 10 human-derived ST23 GBS isolates caused tissue damage and the distribution of pathogens within tissues. The mortality rate of infection was ranged from 76 to 100%, and it was shown that the mortality rate caused by only three human isolates had statistically significant difference compared with fish-derived ST7 strain (P < 0.05, whereas the mortality caused by other seven human isolates did not show significant difference compared with fish-derived ST7 strain. The genome comparison and prophage analysis showed that the major genome difference between virulent and non-virulent ST23 GBS was attributed to the different prophage sequences. The prophage in the P1 region contained about 43% GC and encoded 28–39 proteins, which can mediate the acquisition of YafQ/DinJ structure for GBS by phage recombination. YafQ/DinJ belongs to one of the bacterial toxin–antitoxin (TA systems and allows cells to cope with stress. The ST23 GBS strains carrying this prophage were not pathogenic to tilapia, but the strains without the prophage or carrying the pophage that had gene mutation or deletion, especially the deletion of YafQ/DinJ structure, were highly pathogenic to tilapia. In conclusion, human ST23 GBS is highly pathogenic to fish, which may be related to the phage recombination.

  11. Portadores nasofaríngeos de Neisseria meningitidis en trabajadores con riesgo ocupacional

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    Isabel Martínez

    2010-04-01

    Full Text Available Los portadores de Neisseria meningitidis constituyen la principal fuente de infección y transmisión de la enfermedad meningocócica. Conocer su prevalencia, las características de las cepas aisladas y los factores de riesgos asociados con el estado de portador, aportan datos valiosos al control y vigilancia epidemiológica de esta entidad clínica. Para cumplimentar los objetivos propuestos se realizó un estudio transversal descriptivo de portadores de N. meningitidis en 112 trabajadores de un centro de producción de biofarmacéuticos de La Habana, con edades comprendidas entre 18_60 años. Previo a su realización se cumplió con las exigencias bioéticas requeridas para este tipo de estudio. A todos se les realizó un exudado nasofaríngeo y una encuesta, donde se indagó sobre factores de riesgo (edad, sexo, hacinamiento, hábito de fumar, consumo de bebidas alcohólicas, amigdalectomía y antecedentes de infección respiratoria que favorecen la condición del portador. La identificación de las cepas de N. meningitidis se realizó según métodos convencionales, la clasificación de los serogrupos se hizo por aglutinación en láminas portaobjetos con antisueros comerciales y para la identificación de los serotipos y subtipos se empleó un ensayo inmunoenzimático (ELISA de células enteras con anticuerpos monoclonales. Se detectó un 8% de portadores de N. meningitidis con predominio del serogrupo B (77,8% y el fenotipo más frecuente fue el B:4:P1.4 (33,3%. Al analizar el estado de portador y su asociación con los factores de riesgo, la edad (p = 0,05 y el sexo (p = 0,013 mostraron diferencias significativas. Se demostró la posibilidad del riesgo ocupacional en aquellos individuos que por su profesión están en contacto con microorganismos patógenos

  12. THE SECOND BLIND SPOT: SMALL RETINAL VESSEL VASCULOPATHY AFTER VACCINATION AGAINST NEISSERIA MENINGITIDIS AND YELLOW FEVER.

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    Moysidis, Stavros N; Koulisis, Nicole; Patel, Vivek R; Kashani, Amir H; Rao, Narsing A; Humayun, Mark S; Rodger, Damien C

    2017-01-01

    To describe a case of small retinal vessel vasculopathy postvaccination. We report the case of a 41-year-old white man who presented with a "second blind spot," describing a nasal scotoma in the right eye that started 4 days after vaccinations against Neisseria meningitidis and the yellow fever virus, and after a 2-month period of high stress and decreased sleep. Clinical examination, Humphrey visual field testing, and multimodal imaging with fundus photographs, autofluorescence, fluorescein angiography, and spectral domain optical coherence tomography and angiography were performed. Clinical examination revealed a well-circumscribed, triangular area of retinal graying of about 1-disk diameter in size, located at the border of the temporal macula. This corresponded to a deep scotoma similar in size to the physiologic blind spot on Humphrey visual field 24-2 testing. There was mild hypoautofluoresence of this lesion on autofluorescence, hypofluorescence on fluorescein angiography, and focal attenuation of a small artery just distal to the bifurcation of an artery supplying the involved area. Spectral domain optical coherence tomography through the lesion conveyed hyperreflectivity most prominent in the inner and outer plexiform layers, with extension of the hyperreflectivity into the ganglion cell and inner nuclear layers. Spectral domain optical coherence tomography angiography demonstrated arteriolar and capillary dropout, more pronounced in the superficial retinal layer compared to the deeper retinal layer. At 1-month follow-up, his scotoma improved with monitoring, with reduction from -32 dB to -7 dB on Humphrey visual field testing. There was clinical resolution of the area of graying and decreased hyperreflectivity on spectral domain optical coherence tomography, with atrophy of the inner retina. Spectral domain optical coherence tomography angiography showed progression of arteriolar and capillary dropout, more so in the superficial than in the deep capillary

  13. SENSITIVITAS KUMAN NEISSERIA MENINGITIDIS YANG DIISOLASI DARI JAMAAH HAJI INDONESIA TERHADAP BEBERAPA ANTIBIOTIK

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    Muljati Prijanto

    2012-09-01

    Full Text Available The meningitis meningococcal disease caused by Neisseriae meningitidis is an infection of meninges and cerebrospinal fluid (CSF of the brain and the spinal cord. N. meningitidis is classified into 13 serogroups based on the immunologic reactivity of the capsular polysaccharide. Since 1993 the number of cases and carriers of haj pilgrims from Indonesia have increased. In 1996 the carrier rate was 9,4%, and case fatality rate of Indonesian haj pilgrims in Saudi Arabia was 71,4%. The dominant serogroup was serogroup B. The meningitis vaccine of serogroup B is not available yet. Until now there is not enough information of the laboratory results from the hospital in Saudi Arabia, regarding the strain that caused the infection of haj pilgrims from Indonesia. To prevent transmission of the disease among Haj pilgrims, since 1997, chemoprophylaxis with ciprofloxacine has been given to close contact persons of haj pilgrim patient. The objectives of this study are: First, to know the effectiveness of ciprofloxacin in decreasing the carrier rate of meningitis meningococcus in haj pilgrims. Second, to identify the serogroup of N. meningitidis isolated from carrier or patient and thirdly to know the sensitivity of bacteria to several antibiotics recommended by WHO. Nasofaringeal swabs were taken from 914 haj pilgrims from group of contact person of cases or suspected cases and 311 haj pilgrims from control group at embarkation in Jakarta. Ciprofloxacin was given to the study group in Saudi Arabia. Isolation and serogrouping were carried out for serogroup A, B, C. The result shows that the effectiveness of ciprofloxacin to N. meningitidis in the treated group were 98.58% and control were 85.54%, respectively. The serogroup of N. meningitidis is isolated from 13 carriers of treated group 69,23% could not be classified as serogroup A, B, or C. In the control group, 45 isolated strains from carriers consist of serogroup B 40%, serogroup C 28,9%, serogroup A 20

  14. Surveillance for Neisseria meningitidis Disease Activity and Transmission Using Information Technology.

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    S Sohail Ahmed

    Full Text Available While formal reporting, surveillance, and response structures remain essential to protecting public health, a new generation of freely accessible, online, and real-time informatics tools for disease tracking are expanding the ability to raise earlier public awareness of emerging disease threats. The rationale for this study is to test the hypothesis that the HealthMap informatics tools can complement epidemiological data captured by traditional surveillance monitoring systems for meningitis due to Neisseria meningitides (N. meningitides by highlighting severe transmissible disease activity and outbreaks in the United States.Annual analyses of N. meningitides disease alerts captured by HealthMap were compared to epidemiological data captured by the Centers for Disease Control's Active Bacterial Core surveillance (ABCs for N. meningitides. Morbidity and mortality case reports were measured annually from 2010 to 2013 (HealthMap and 2005 to 2012 (ABCs.HealthMap N. meningitides monitoring captured 80-90% of alerts as diagnosed N. meningitides, 5-20% of alerts as suspected cases, and 5-10% of alerts as related news articles. HealthMap disease alert activity for emerging disease threats related to N. meningitides were in agreement with patterns identified historically using traditional surveillance systems. HealthMap's strength lies in its ability to provide a cumulative "snapshot" of weak signals that allows for rapid dissemination of knowledge and earlier public awareness of potential outbreak status while formal testing and confirmation for specific serotypes is ongoing by public health authorities.The underreporting of disease cases in internet-based data streaming makes inadequate any comparison to epidemiological trends illustrated by the more comprehensive ABCs network published by the Centers for Disease Control. However, the expected delays in compiling confirmatory reports by traditional surveillance systems (at the time of writing, ABCs data

  15. Identification and characterization of AckA-dependent protein acetylation in Neisseria gonorrhoeae.

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    Deborah M B Post

    Full Text Available Neisseria gonorrhoeae, the causative agent of gonorrhea, has a number of factors known to contribute to pathogenesis; however, a full understanding of these processes and their regulation has proven to be elusive. Post-translational modifications (PTMs of bacterial proteins are now recognized as one mechanism of protein regulation. In the present study, Western blot analyses, with an anti-acetyl-lysine antibody, indicated that a large number of gonococcal proteins are post-translationally modified. Previous work has shown that Nε-lysine acetylation can occur non-enzymatically with acetyl-phosphate (AcP as the acetyl donor. In the current study, an acetate kinase mutant (1291ackA, which accumulates AcP, was generated in N. gonorrhoeae. Broth cultures of N. gonorrhoeae 1291wt and 1291ackA were grown, proteins extracted and digested, and peptides containing acetylated-lysines (K-acetyl were affinity-enriched from both strains. Mass spectrometric analyses of these samples identified a total of 2686 unique acetylation sites. Label-free relative quantitation of the K-acetyl peptides derived from the ackA and wild-type (wt strains demonstrated that 109 acetylation sites had an ackA/wt ratio>2 and p-values <0.05 in at least 2/3 of the biological replicates and were designated as "AckA-dependent". Regulated K-acetyl sites were found in ribosomal proteins, central metabolism proteins, iron acquisition and regulation proteins, pilus assembly and regulation proteins, and a two-component response regulator. Since AckA is part of a metabolic pathway, comparative growth studies of the ackA mutant and wt strains were performed. The mutant showed a growth defect under aerobic conditions, an inability to grow anaerobically, and a defect in biofilm maturation. In conclusion, the current study identified AckA-dependent acetylation sites in N. gonorrhoeae and determined that these sites are found in a diverse group of proteins. This work lays the foundation for

  16. Differences in the population structure of Neisseria meningitidis in two Australian states: Victoria and Western Australia.

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    Shakeel Mowlaboccus

    Full Text Available Neisseria meningitidis is the causative agent of invasive meningococcal disease (IMD. A recombinant vaccine called Bexsero® incorporates four subcapsular antigens (fHbp, NHBA, NadA and PorA which are used to assign a Bexsero® antigen sequence type (BAST to each meningococcal strain. The vaccine elicits an immune response against combinations of variants of these antigens which have been grouped into specific BAST profiles that have been shown to have different distributions within geographical locations thus potentially affecting the efficacy of the vaccine. In this study, invasive meningococcal disease isolates from the western seaboard of Australia (Western Australia; WA were compared to those from the south-eastern seaboard (Victoria; VIC from 2008 to 2012. Whole-genome sequencing (WGS of 131 meningococci from VIC and 70 meningococci from WA were analysed for MLST, FetA and BAST profiling. Serogroup B predominated in both jurisdictions and a total of 10 MLST clonal complexes (cc were shared by both states. Isolates belonging to cc22, cc103 and cc1157 were unique to VIC whilst isolates from cc60 and cc212 were unique to WA. Clonal complex 41/44 represented one-third of the meningococcal population in each state but the predominant ST was locally different: ST-6058 in VIC and ST-146 in WA. Of the 108 BAST profiles identified in this collection, only 9 BASTs were simultaneously observed in both states. A significantly larger proportion of isolates in VIC harboured alleles for the NHBA-2 peptide and fHbp-1, antigenic variants predicted to be covered by the Bexsero® vaccine. The estimate for vaccine coverage in WA (47.1% [95% CI: 41.1-53.1%] was significantly lower than that in VIC (66.4% [95% CI: 62.3-70.5%]. In conclusion, the antigenic structure of meningococci causing invasive disease in two geographically distinct states of Australia differed significantly during the study period which may affect vaccine effectiveness and highlights the

  17. Antiseptic mouthwash against pharyngeal Neisseria gonorrhoeae: a randomised controlled trial and an in vitro study.

    Science.gov (United States)

    Chow, Eric Pf; Howden, Benjamin P; Walker, Sandra; Lee, David; Bradshaw, Catriona S; Chen, Marcus Y; Snow, Anthony; Cook, Stuart; Fehler, Glenda; Fairley, Christopher K

    2017-03-01

    Gonorrhoea is increasing among men who have sex with men (MSM). We aimed to determine whether Listerine, a commercial mouthwash product, has an inhibitory effect against Neisseria gonorrhoeae in a randomised controlled trial (RCT) and an in vitro study, and therefore may be a potentially useful agent for gonorrhoea control. In vitro: a suspension of ∼10 8 colony forming units per mL (CFU/mL) of N. gonorrhoeae was added to a serial of dilutions (up to 1:32) of alcohol-containing Listerine mouthwashes (Cool Mint and Total Care) for 1 min. A 10 µL aliquot was spread over the surface of a gonococcal agar plate and the number of N. gonorrhoeae colonies present at each dilution was calculated. The phosphate buffered saline (PBS) was used as a control. RCT: we recruited MSM with pharyngeal gonorrhoea who returned for treatment at the Melbourne Sexual Health Centre between May 2015 and February 2016. Untreated men were randomised to rinse and gargle either Listerine Cool Mint or saline for 1 min. Pharyngeal swabs were taken before and after rinsing and gargling for culture of N. gonorrhoeae . The analysis included only men who were culture positive for N. gonorrhoeae before using the allocated solution on the day of recruitment. In vitro: Listerine mouthwashes at dilutions of up to 1:4 for 1 min resulted in significant reduction of total N. gonorrhoeae counts but PBS has no inhibitory effect against N. gonorrhoeae . RCT: a total of 196 MSM were recruited, 58 (30%) were culture positive before using the solution. After gargling the allocated solution, men in the Listerine group were significantly less likely to be culture positive on the pharyngeal surface (52%) compared with men in the saline group (84%) (p=0.013). This data suggest Listerine, significantly reduces the amount of N. gonorrhoeae on the pharyngeal surface. With daily use it may increase gonococcal clearance and have important implications for prevention strategies. ACTRN12615000716561. Published by

  18. Identifying optimal vaccination strategies for serogroup A Neisseria meningitidis conjugate vaccine in the African meningitis belt.

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    Sara Tartof

    Full Text Available The optimal long-term vaccination strategies to provide population-level protection against serogroup A Neisseria meningitidis (MenA are unknown. We developed an age-structured mathematical model of MenA transmission, colonization, and disease in the African meningitis belt, and used this model to explore the impact of various vaccination strategies.The model stratifies the simulated population into groups based on age, infection status, and MenA antibody levels. We defined the model parameters (such as birth and death rates, age-specific incidence rates, and age-specific duration of protection using published data and maximum likelihood estimation. We assessed the validity of the model by comparing simulated incidence of invasive MenA and prevalence of MenA carriage to observed incidence and carriage data.The model fit well to observed age- and season-specific prevalence of carriage (mean pseudo-R2 0.84 and incidence of invasive disease (mean R2 0.89. The model is able to reproduce the observed dynamics of MenA epidemics in the African meningitis belt, including seasonal increases in incidence, with large epidemics occurring every eight to twelve years. Following a mass vaccination campaign of all persons 1-29 years of age, the most effective modeled vaccination strategy is to conduct mass vaccination campaigns every 5 years for children 1-5 years of age. Less frequent campaigns covering broader age groups would also be effective, although somewhat less so. Introducing conjugate MenA vaccine into the EPI vaccination schedule at 9 months of age results in higher predicted incidence than periodic mass campaigns.We have developed the first mathematical model of MenA in Africa to incorporate age structures and progressively waning protection over time. Our model accurately reproduces key features of MenA epidemiology in the African meningitis belt. This model can help policy makers consider vaccine program effectiveness when determining the

  19. Sustained transmission of high-level azithromycin-resistant Neisseria gonorrhoeae in England: an observational study.

    Science.gov (United States)

    Fifer, Helen; Cole, Michelle; Hughes, Gwenda; Padfield, Simon; Smolarchuk, Christa; Woodford, Neil; Wensley, Adrian; Mustafa, Nazim; Schaefer, Ulf; Myers, Richard; Templeton, Kate; Shepherd, Jill; Underwood, Anthony

    2018-05-01

    Between Nov 3, 2014, and Feb 24, 2017, 70 cases of high-level azithromycin-resistant (HL-AziR; minimum inhibitory concentration [MIC] ≥256 mg/L) Neisseria gonorrhoeae were reported from across England. Whole-genome sequencing was done to investigate this outbreak to determine whether the ongoing outbreak represented clonal spread of an HL-AziR N gonorrhoeae strain identified in Leeds. We also wanted to elucidate the molecular mechanisms of azithromycin resistance in N gonorrhoeae in the UK. In this observational study, whole-genome sequencing was done on the HL-AziR N gonorrhoeae isolates from England. As comparators, 110 isolates from the UK and Ireland with a range of azithromycin MICs were also sequenced, including eight isolates from Scotland with azithromycin MICs ranging from 0·12 mg/L to 1·00 mg/L that were N gonorrhoeae multi-antigen sequence type 9768 (ST9768), which was the sequence type initially responsible for the outbreak. The presence of mutations or genes associated with azithromycin resistance was also investigated. 37 of the 60 HL-AziR isolates from England belonged to ST9768, and were genetically similar (mean 4·3 single-nucleotide polymorphisms). A 2059A→G mutation was detected in three or all four alleles of the 23S rRNA gene. Five susceptible ST9768 isolates had one mutated 23S rRNA allele and one low-level resistant ST9768 isolate had two mutated alleles. Sustained transmission of a successful HL-AziR clone was seen across England. Mutation 2059A→G was found in isolates with lower azithromycin MICs. Azithromycin exposure might have provided the selection pressure for one or two mutated copies of the 23S rRNA gene to recombine with wild-type copies, leading to three or four mutated copies and the HL-AziR phenotype. HL-AziR could emerge in isolates with low azithromycin MICs and eliminate the effectiveness of azithromycin as part of dual therapy for the treatment of gonorrhoea. Public Health England. Copyright © 2018 Elsevier Ltd. All

  20. Optimization of Molecular Approaches to Genogroup Neisseria meningitidis Carriage Isolates and Implications for Monitoring the Impact of New Serogroup B Vaccines.

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    Eduardo Rojas

    Full Text Available The reservoir for Neisseria meningitidis (Nm is the human oropharynx. Implementation of Nm serogroup C (NmC glycoconjugate vaccines directly reduced NmC carriage. Prophylactic vaccines are now available to prevent disease caused by the five major Nm disease causing serogroups (ABCWY. Nm serogroup B (NmB vaccines are composed of antigens that are conserved across Nm serogroups and therefore have the potential to impact all Nm carriage. To assess the effect of these vaccines on carriage, standardized approaches to identify and group Nm are required. Real-time PCR (rt-PCR capsule grouping assays that were internally controlled to confirm Nm species were developed for eight serogroups associated with carriage (A, B, C, E, W, X, Y and Z. The grouping scheme was validated using diverse bacterial species associated with carriage and then used to evaluate a collection of diverse Nm carriage isolates (n=234. A scheme that also included porA and ctrA probes was able to speciate the isolates, while ctrA also provided insights on the integrity of the polysaccharide loci. Isolates were typed for the Nm vaccine antigen factor H binding protein (fHbp, and were found to represent the known diversity of this antigen. The porA rt-PCR yielded positive results with all 234 of the Nm carriage isolates. Genogrouping assays classified 76.5% (179/234 of these isolates to a group, categorized 53 as nongenogroupable (NGG and two as mixed results. Thirty seven NGG isolates evidenced a disrupted capsular polysaccharide operon judged by a ctrA negative result. Only 28.6% (67/234 of the isolates were serogrouped by slide agglutination (SASG, highlighting the reduced capability of carriage strains to express capsular polysaccharide. These rt-PCR assays provide a comprehensive means to identify and genogroup N. meningitidis in carriage studies used to guide vaccination strategies and to assess the impact of novel fHbp containing vaccines on meningococcal carriage.

  1. Prevalence of Entamoeba species in captive primates in zoological gardens in the UK

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    Carl S. Regan

    2014-07-01

    Full Text Available The aim of this study was to determine the prevalence of amoebic infection in non-human primates (NHPs from six Zoological gardens in the United Kingdom. Initially, 126 faecal samples were collected from 37 individually identified NHPs at Twycross Zoo, UK, and were subjected to microscopic examination. A subsequent, nationwide experiment included 350 faecal samples from 89 individually identified NHPs and 73 unidentified NHPs from a number of UK captive wildlife facilities: Twycross Zoo (n = 60, Colchester Zoo (n = 3, Edinburgh Zoo (n = 6, Port Lympne Wild Animal Park (n = 58, Howletts Wild Animal Park (n = 31, and Cotswold Wildlife Park (n = 4. Samples were examined by PCR and sequencing using four specific primer sets designed to differentiate between the pathogenic E. histolytica, the non-pathogenic E. dispar, and non-pathogenic uninucleate cyst-producing Entamoeba species. In the first experiment, Entamoeba was detected in 30 primates (81.1%. Six (16.2% primates were infected with E. histolytica species complex. The highest carriage of Entamoeba species was found in Old World Colobinae primates. In the nationwide experiment, molecular analysis of faecal samples revealed notable rates of Entamoeba infection (101 samples, 28.9%, including one sample infected with E. histolytica, 14 samples with E. dispar, and 86 samples with uninucleated-cyst producing Entamoeba species. Sequences of positive uninucleated-cyst producing Entamoeba samples from Twycross Zoo clustered with the E. polecki reference sequences ST4 reported in Homo sapiens, and are widely separated from other Entamoeba species. These findings suggest a low prevalence of the pathogenic Entamoeba infection, but notable prevalence of non-pathogenic E. polecki infection in NHPs in the UK.

  2. Colonization by non-pathogenic bacteria alters mRNA expression of cytochromes P450 in originally germ-free mice.

    Science.gov (United States)

    Jourová, L; Anzenbacher, P; Lišková, B; Matušková, Z; Hermanová, P; Hudcovic, T; Kozáková, H; Hrnčířová, L; Anzenbacherová, E

    2017-11-01

    Gut microbiota provides a wide range of beneficial function for the host and has an immense effect on the host's health state. It has also been shown that gut microbiome is often involved in the biotransformation of xenobiotics; however, the molecular mechanisms of the interaction between the gut bacteria and the metabolism of drugs by the host are still unclear. To investigate the effect of microbial colonization on messenger RNA (mRNA) expression of liver cytochromes P450 (CYPs), the main drug-metabolizing enzymes, we used germ-free (GF) mice, lacking the intestinal flora and mice monocolonized by non-pathogenic bacteria Lactobacillus plantarum NIZO2877 or probiotic bacteria Escherichia coli Nissle 1917 compared to specific pathogen-free (SPF) mice. Our results show that the mRNA expression of Cyp1a2 and Cyp2e1 was significantly increased, while the expression of Cyp3a11 mRNA was decreased under GF conditions compared to the SPF mice. The both bacteria L. plantarum NIZO2877 and E. coli Nissle 1917 given to the GF mice decreased the level of Cyp1a2 mRNA and normalized it to the control level. On the other hand, the colonization by these bacteria had no effect on the expression of Cyp3a11 mRNA in the liver of the GF mice (which remained decreased). Surprisingly, monocolonization with chosen bacterial strains has shown a different effect on the expression of Cyp2e1 mRNA in GF mice. Increased level of Cyp2e1 expression observed in the GF mice was found also in mice colonized by L. plantarum NIZO2877 ; however, the colonization with probiotic E. coli Nissle 1917 caused a decrease in Cyp2e1 expression and partially restored the SPF mice conditions.

  3. Case Report of Urethritis in a Male Patient Infected with Two Different Isolates of Multiple Drug-Resistant Neisseria gonorrhoeae

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    Lamiaa Al-Madboly

    2017-11-01

    Full Text Available We report a brief description of a case suffering from bacterial urethritis, conjunctivitis, and arthritis, caused by two different isolates of multiple drug-resistant Neisseria gonorrhoeae. Initial diagnosis was dependent on the patient history, clinical findings, symptoms, and the bacteriological data. Polymerase chain reaction confirmed the identification of the pathogens. Random amplified polymorphic DNA revealed two different patterns. Susceptibility testing was performed using Kirby–Bauer disk diffusion method and the minimum inhibitory concentration was also determined. It revealed multiple drug resistance associated with β-lactamase production. Only gentamicin, rifampicin, and azithromycin were active against the test pathogens. A dual therapy was initiated using gentamicin as well as azithromycin to treat the possible co-infection with Chlamydia trachomatis. Complete recovery of the patient achieved with resolved symptoms a week later.

  4. Case Report of Urethritis in a Male Patient Infected with Two Different Isolates of Multiple Drug-Resistant Neisseria gonorrhoeae.

    Science.gov (United States)

    Al-Madboly, Lamiaa; Gheida, Shereen

    2017-01-01

    We report a brief description of a case suffering from bacterial urethritis, conjunctivitis, and arthritis, caused by two different isolates of multiple drug-resistant Neisseria gonorrhoeae . Initial diagnosis was dependent on the patient history, clinical findings, symptoms, and the bacteriological data. Polymerase chain reaction confirmed the identification of the pathogens. Random amplified polymorphic DNA revealed two different patterns. Susceptibility testing was performed using Kirby-Bauer disk diffusion method and the minimum inhibitory concentration was also determined. It revealed multiple drug resistance associated with β-lactamase production. Only gentamicin, rifampicin, and azithromycin were active against the test pathogens. A dual therapy was initiated using gentamicin as well as azithromycin to treat the possible co-infection with Chlamydia trachomatis . Complete recovery of the patient achieved with resolved symptoms a week later.

  5. Prevalencia de infeccion por Neisseria Gonorrhoeae en trabajadoras sexuales atendidas en el Centro de Salud Antivenereo de Lima, 1995

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    José L Portilla C

    1997-01-01

    Full Text Available Entre Junio a Diciembre del año 1995, se estudiaron a 233 trabajadoras sexuales legales con control sanitario y 171 trabajadoras sexuales clandestinas que evaden dicho control sanitario, quienes fueron atendidas en el Centro de Salud Antivenéreo de Lima con la finalidad de investigar la frecuencia de las infecciones gonocócicas en estos grupos de población y detectar cepas de Neisseria gonorrhoeae productoras de beta-lactamasa. Se encontró diferencia significativa (p=0,014 entre las frecuencias de aislamiento del gonococo procedente de las trabajadores sexuales legales, 1,72% (4/233, en comparación con lo encontrado en las clandestinas, 7,02% (12/171. Del total de las cepas aisladas de N. gonorrhoeae, el 37,5% (6/16 resultaron ser productoras de beta-lactamasa.

  6. Experimental gonococcal infection in male volunteers: Cumulative experience with Neisseria gonorrhoeae strains FA1090 and MS11mkC

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    Marcia Metzgar Hobbs

    2011-05-01

    Full Text Available Experimental infection of male volunteers with Neisseria gonorrhoeae is safe and reproduces the clinical features of naturally acquired gonococcal urethritis. Human inoculation studies have helped define the natural history of experimental infection with two well-characterized strains of N. gonorrhoeae, FA1090 and MS11mkC. The human model has proved useful for testing the importance of putative gonococcal virulence factors for urethral infection in men. Studies with isogenic mutants have improved our understanding of the requirements for gonococcal LOS structures, pili, opacity proteins, IgA1 protease and the ability of infecting organisms to obtain iron from human transferrin and lactoferrin during uncomplicated urethritis. The model also presents opportunities to examine innate host immune responses that may be exploited or improved in development and testing of gonococcal vaccines. Here we review results to date with human experimental gonorrhea.

  7. Expression, purification and preliminary X-ray analysis of the Neisseria meningitidis outer membrane protein PorB

    Energy Technology Data Exchange (ETDEWEB)

    Tanabe, Mikio; Iverson, Tina M.; (Vanderbilt)

    2010-01-28

    The Neisseria meningitidis outer membrane protein PorB was expressed in Escherichia coli and purified from inclusion bodies by denaturation in urea followed by refolding in buffered LDAO on a size-exclusion column. PorB has been crystallized in three different crystal forms: C222, R32 and P6{sub 3}. The C222 crystal form may contain either one or two PorB monomers in the asymmetric unit, while both the R32 and P6{sub 3} crystal forms contained one PorB monomer in the asymmetric unit. Of the three, the P6{sub 3} crystal form had the best diffraction quality, yielding data extending to 2.3 {angstrom} resolution.

  8. Structure of the cold-shock domain protein from Neisseria meningitidis reveals a strand-exchanged dimer

    Energy Technology Data Exchange (ETDEWEB)

    Ren, Jingshan [The Oxford Protein Production Facility, Henry Wellcome Building for Genomic Medicine, University of Oxford, Roosevelt Drive, Oxford OX3 7BN (United Kingdom); Division of Structural Biology, Henry Wellcome Building for Genomic Medicine, University of Oxford, Roosevelt Drive, Oxford OX3 7BN (United Kingdom); Nettleship, Joanne E.; Sainsbury, Sarah [The Oxford Protein Production Facility, Henry Wellcome Building for Genomic Medicine, University of Oxford, Roosevelt Drive, Oxford OX3 7BN (United Kingdom); Saunders, Nigel J. [Bacterial Pathogenesis and Functional Genomics Group, Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE (United Kingdom); Owens, Raymond J., E-mail: ray@strubi.ox.ac.uk [The Oxford Protein Production Facility, Henry Wellcome Building for Genomic Medicine, University of Oxford, Roosevelt Drive, Oxford OX3 7BN (United Kingdom)

    2008-04-01

    The X-ray crystal structure of the cold-shock domain protein from N. meningitidis reveals a strand-exchanged dimer. The structure of the cold-shock domain protein from Neisseria meningitidis has been solved to 2.6 Å resolution and shown to comprise a dimer formed by the exchange of two β-strands between protein monomers. The overall fold of the monomer closely resembles those of other bacterial cold-shock proteins. The neisserial protein behaved as a monomer in solution and was shown to bind to a hexathymidine oligonucleotide with a stoichiometry of 1:1 and a K{sub d} of 1.25 µM.

  9. Infection of Human Fallopian Tube Epithelial Cells with Neisseria gonorrhoeae Protects Cells from Tumor Necrosis Factor Alpha-Induced Apoptosis

    Science.gov (United States)

    Morales, Priscilla; Reyes, Paz; Vargas, Macarena; Rios, Miguel; Imarai, Mónica; Cardenas, Hugo; Croxatto, Horacio; Orihuela, Pedro; Vargas, Renato; Fuhrer, Juan; Heckels, John E.; Christodoulides, Myron; Velasquez, Luis

    2006-01-01

    Following infection with Neisseria gonorrhoeae, bacteria may ascend into the Fallopian tubes (FT) and induce salpingitis, a major cause of infertility. In the FT, interactions between mucosal epithelial cells and gonococci are pivotal events in the pathogen's infection cycle and the inflammatory response. In the current study, primary FT epithelial cells were infected in vitro with different multiplicities of infection (MOI) of Pil+ Opa+ gonococci. Bacteria showed a dose-dependent association with cells and induced the secretion of tumor necrosis factor alpha (TNF-α). A significant finding was that gonococcal infection (MOI = 1) induced apoptosis in approximately 30% of cells, whereas increasing numbers of bacteria (MOI = 10 to 100) did not induce apoptosis. Apoptosis was observed in only 11% of cells with associated bacteria, whereas >84% of cells with no adherent bacteria were apoptotic. TNF-α was a key contributor to apoptosis, since (i) culture supernatants from cells infected with gonococci (MOI = 1) induced apoptosis in naïve cultures, suggesting that a soluble factor was responsible; (ii) gonococcal infection-induced apoptosis was inhibited with anti-TNF-α antibodies; and (iii) the addition of exogenous TNF-α induced apoptosis, which was inhibited by the presence of increasing numbers of bacteria (MOI = 10 to 100). These data suggest that TNF-α-mediated apoptosis of FT epithelial cells is likely a primary host defense mechanism to prevent pathogen colonization. However, epithelial cell-associated gonococci have evolved a mechanism to protect the cells from undergoing TNF-α-mediated apoptosis, and this modulation of the host innate response may contribute to establishment of infection. Understanding the antiapoptotic mechanisms used by Neisseria gonorrhoeae will inform the pathogenesis of salpingitis and could suggest new intervention strategies for prevention and treatment of the disease. PMID:16714596

  10. Comparison of dot-ELISA and standard ELISA for detection of Neisseria meningitidis outer membrane complex-specific antibodies

    Directory of Open Access Journals (Sweden)

    Elza FT Belo

    Full Text Available Dot-ELISA using the outer membrane complex antigens of Neisseria meningitidis as a target was standardized for rapid detection of meningococcal-specific antibodies in human serum. We investigated the level of meningococcal-specific IgG, IgA, and IgM in serum using dot-ELISA with outer membrane antigens prepared from Neisseria meningitidis serotype B:4.19:P1.15,3,7,9 (a strain isolated from a Brazilian epidemic. The dot-ELISA is based on the same principles as the standard ELISA and is useful for detection of anti-N. meningitidis B antibodies in serum of patients with meningococcal infections. For the assay, outer membrane complexes (OMCs were absorbed by nitrocellulose membrane and blocked with a 5% skim milk solution. Serum samples were drawn upon hospital admission and during convalescence from patients with meningococcal septicemia, and single samples were drawn from uninfected controls. We retrospectively examined a total of 57 serum samples: 35 from patients infected with N. meningitidis B, 12 from patients infected with Haemophilus influenzae b, and 10 from health individuals. When performed at room temperature, dot-ELISA took approximately four hours to perform, and the optimum antigen concentration was 0.42 µg per dot. The specificity of IgG, IgM, and IgA demonstrates that dot-ELISA using OMCs from N. meningitidis B as a target is suitable for serologic verification of clinically suspected meningococcal disease in patients and for titer determination of antibodies produced during different phases of natural infection. Furthermore, the sensitivity of dot-ELISA was comparable to that of standard ELISA. Overall, dot-ELISA is simple to perform, rapid, and low cost. Further validation of the test as a screening tool is required.

  11. Encuesta de portadores de Neisseria meningitidis en el Área de Salud de Gran Canaria

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    García Rojas Amós

    2000-01-01

    Full Text Available FUNDAMENTOS: Se plantea A Conocer la tasa de portadores y los tipos circulantes de Neisseria Meningitidis en la población residente en el área de salud de Gran Canaria. B Conocer el patrón de distribución de estos portadores. MÉTODOS: Se realizó un diseño descriptivo transversal, con un muestreo aleatorio en etapas múltiples y por conglomerados. Se determinó un tamaño muestral mínimo de 707 personas para una prevalencia esperada del 8,6 %, con una confianza del 95,6 % y precisión de 0,02. Asumiendo que un 15 % de las personas no quisieran colaborar, se incrementó el tamaño muestral a 831 personas, distribuidas en cada conglomerado de manera proporcional a la población existente. Este tamaño se distribuyó a su vez, en cuatro grandes grupos de edad y sexo, proporcionalmente a su importancia en cada zona básica de salud seleccionada aleatoriamente. Los individuos de la muestra se identificaban entre los que acudían a las unidades de extracción, y una vez superados los criterios de exclusión se les solicitaba su colaboración voluntaria en el estudio. Si aceptaban, se les cumplimentaba un cuestionario que englobaba diferentes variables de interés epidemiológico y se les realizaba un frotis faríngeo. Al haber seleccionado los equipos de Atención Primaria con muestreo aleatorio simple y seguir el mismo método para elegir los individuos dentro de ellos, la estimación de la prevalencia se realizó mediante estimador no sesgado. RESULTADOS: Se obtuvieron un total de 828 muestras, lo que supuso un 99,6% de las previstas. Salvo tres, todos los individuos seleccionados participaron voluntariamente en el estudio, lo que le confiere una alta representatividad. Todas las cepas obtenidas correspondían a N. Meningitidis Serogrupo B, salvo una identificada como N. Meningitidis Serogrupo C Sero/Subtipo 4:P1.2,5. Las cepas de N. Meningitidis serogrupo B identificadas, correspondían a 25 serosubtipos diferentes. La prevalencia puntual

  12. Immunogenicity and protective efficacy of a single-dose live non-pathogenic Escherichia coli oral vaccine against F4-positive enterotoxigenic Escherichia coli challenge in pigs.

    Science.gov (United States)

    Fairbrother, John Morris; Nadeau, Éric; Bélanger, Louise; Tremblay, Cindy-Love; Tremblay, Danielle; Brunelle, Mélanie; Wolf, Regina; Hellmann, Klaus; Hidalgo, Álvaro

    2017-01-05

    Enterotoxigenic Escherichia coli strains expressing F4 (K88) fimbriae (F4-ETEC) are one of the most important causes of post-weaning diarrhea (PWD) in pigs. F4, a major antigen, plays an important role in the early steps of the infection. Herein, the efficacy of a live oral vaccine consisting of a non-pathogenic E. coli strain expressing F4 for protection of pigs against PWD was evaluated. Three blinded, placebo-controlled, block design, parallel-group confirmatory experiments were conducted, using an F4-ETEC PWD challenge model, each with a different vaccination-challenge interval (3, 7, and 21days). The pigs were vaccinated via the drinking water with a single dose of the Coliprotec® F4 vaccine one day post-weaning. Efficacy was assessed by evaluating diarrhea, clinical observations, intestinal fluid accumulation, weight gain, intestinal colonization and fecal shedding of F4-ETEC. The immune response was evaluated by measuring serum and intestinal F4-specific antibodies. The administration of the vaccine resulted in a significant reduction of the incidence of moderate to severe diarrhea, ileal colonization by F4-ETEC, and fecal shedding of F4-ETEC after the heterologous challenge at 7 and 21days post-vaccination. The 7-day onset of protection was associated with an increase of serum anti-F4 IgM whereas the 21-day duration of protection was associated with an increase of both serum anti-F4 IgM and IgA. Significant correlations between levels of serum and intestinal secretory anti-F4 antibodies were detected. Maternally derived F4-specific serum antibodies did not interfere with the vaccine efficacy. The evaluation of protection following a challenge three days after vaccination showed a reduction of the severity and the duration of diarrhea and of fecal shedding of F4-ETEC. The 7-day onset and the 21-day duration of protection induced by Coliprotec® F4 vaccine administered once in drinking water to pigs of at least 18days of age were confirmed by protection

  13. Validation of Baking To Control Salmonella Serovars in Hamburger Bun Manufacturing, and Evaluation of Enterococcus faecium ATCC 8459 and Saccharomyces cerevisiae as Nonpathogenic Surrogate Indicators.

    Science.gov (United States)

    Channaiah, Lakshmikantha H; Holmgren, Elizabeth S; Michael, Minto; Sevart, Nicholas J; Milke, Donka; Schwan, Carla L; Krug, Matthew; Wilder, Amanda; Phebus, Randall K; Thippareddi, Harshavardhan; Milliken, George

    2016-04-01

    This study was conducted to validate a simulated commercial baking process for hamburger buns to destroy Salmonella serovars and to determine the appropriateness of using nonpathogenic surrogates (Enterococcus faecium ATCC 8459 or Saccharomyces cerevisiae) for in-plant process validation studies. Wheat flour was inoculated (∼6 log CFU/g) with three Salmonella serovars (Typhimurium, Newport, or Senftenberg 775W) or with E. faecium. Dough was formed, proofed, and baked to mimic commercial manufacturing conditions. Buns were baked for up to 13 min in a conventional oven (218.3°C), with internal crumb temperature increasing to ∼100°C during the first 8 min of baking and remaining at this temperature until removal from the oven. Salmonella and E. faecium populations were undetectable by enrichment (>6-log CFU/g reductions) after 9.0 and 11.5 min of baking, respectively, and ≥5-log-cycle reductions were achieved by 6.0 and 7.75 min, respectively. D-values of Salmonella (three-serovar cocktail) and E. faecium 8459 in dough were 28.64 and 133.33, 7.61 and 55.67, and 3.14 and 14.72 min at 55, 58, and 61°C, respectively, whereas D-values of S. cerevisiae were 18.73, 5.67, and 1.03 min at 52, 55, and 58°C, respectivly. The z-values of Salmonella, E. faecium, and S. cerevisiae were 6.58, 6.25, and 4.74°C, respectively. A high level of thermal lethality was observed for baking of typical hamburger bun dough, resulting in rapid elimination of high levels of the three-strain Salmonella cocktail; however, the lethality and microbial destruction kinetics should not be extrapolated to other bakery products without further research. E. faecium demonstrated greater thermal resistance compared with Salmonella during bun baking and could serve as a conservative surrogate to validate thermal process lethality in commercial bun baking operations. Low thermal tolerance of S. cerevisiae relative to Salmonella serovars limits its usefulness as a surrogate for process validations.

  14. Characterization of a non-pathogenic H5N1 influenza virus isolated from a migratory duck flying from Siberia in Hokkaido, Japan, in October 2009

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    Okamatsu Masatoshi

    2011-02-01

    Full Text Available Abstract Background Infection with H5N1 highly pathogenic avian influenza viruses (HPAIVs of domestic poultry and wild birds has spread to more than 60 countries in Eurasia and Africa. It is concerned that HPAIVs may be perpetuated in the lakes in Siberia where migratory water birds nest in summer. To monitor whether HPAIVs circulate in migratory water birds, intensive surveillance of avian influenza has been performed in Mongolia and Japan in autumn each year. Until 2008, there had not been any H5N1 viruses isolated from migratory water birds that flew from their nesting lakes in Siberia. In autumn 2009, A/mallard/Hokkaido/24/09 (H5N1 (Mal/Hok/24/09 was isolated from a fecal sample of a mallard (Anas platyrhynchos that flew from Siberia to Hokkaido, Japan. The isolate was assessed for pathogenicity in chickens, domestic ducks, and quails and analyzed antigenically and phylogenetically. Results No clinical signs were observed in chickens inoculated intravenously with Mal/Hok/24/09 (H5N1. There was no viral replication in chickens inoculated intranasally with the isolate. None of the domestic ducks and quails inoculated intranasally with the isolate showed any clinical signs. There were no multiple basic amino acid residues at the cleavage site of the hemagglutinin (HA of the isolate. Each gene of Mal/Hok/24/09 (H5N1 is phylogenetically closely related to that of influenza viruses isolated from migratory water birds that flew from their nesting lakes in autumn. Additionally, the antigenicity of the HA of the isolate was similar to that of the viruses isolated from migratory water birds in Hokkaido that flew from their northern territory in autumn and different from those of HPAIVs isolated from birds found dead in China, Mongolia, and Japan on the way back to their northern territory in spring. Conclusion Mal/Hok/24/09 (H5N1 is a non-pathogenic avian influenza virus for chickens, domestic ducks, and quails, and is antigenically and genetically

  15. Endangered Species

    Science.gov (United States)

    EPA's Endangered Species Protection Program helps promote recovery of listed species. The ESPP determines if pesticide use in a geographic area may affect any listed species. Find needed limits on pesticide use in Endangered Species Protection Bulletins.

  16. Desarrollo de una Sonda de ADN de Origen Plasmídico para la identificación y detección de Neisseria gonorrhoeae.

    OpenAIRE

    Torres Sánchez, María José

    2016-01-01

    Neisseria gonorrhoeae, es el agente causal de la gonococia, enfermedad de transmisión sexual reconocida como una de las causas principales de morbilidad en muchas zonas del mundo (Donegan, 1985). La gonococia es a menudo recurrente y ocasionalmente produce complicaciones, como la enfermedad inflamatoria pélvica –causa de embarazos ectópicos e infertilidad--, la infección gonocócica diseminada y la epididimitis, entre otras. Ya que el diagnós...

  17. Characterization of a catalase-deficient strain of Neisseria gonorrhoeae: evidence for the significance of catalase in the biology of N. gonorrhoeae.

    OpenAIRE

    Johnson, S R; Steiner, B M; Cruce, D D; Perkins, G H; Arko, R J

    1993-01-01

    We obtained a catalase-deficient (Kat-) strain of Neisseria gonorrhoeae isolated from a patient who had been unsuccessfully treated with penicillin. Quantitative enzyme assays and electrophoresis of cell extracts on native polyacrylamide gels subsequently stained for catalase and peroxidase activities failed to detect both enzymes. The strain exhibited no growth anomalies or unusual requirements when grown under ordinary laboratory conditions. However, the Kat- strain proved extremely sensiti...

  18. Rapid species specific identification and subtyping of Yersinia enterocolitica by MALDI-TOF mass spectrometry.

    Science.gov (United States)

    Stephan, Roger; Cernela, Nicole; Ziegler, Dominik; Pflüger, Valentin; Tonolla, Mauro; Ravasi, Damiana; Fredriksson-Ahomaa, Maria; Hächler, Herbert

    2011-11-01

    Yersinia enterocolitica are Gram-negative pathogens and known as important causes of foodborne infections. Rapid and reliable identification of strains of the species Y. enterocolitica within the genus Yersinia and the differentiation of the pathogenic from the non-pathogenic biotypes has become increasingly important. We evaluated here the application of matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) for rapid species identification and subtyping of Y. enterocolitica. To this end, we developed a reference MS database library including 19 Y. enterocolitica (non-pathogenic biotype 1A and pathogenic biotypes 2 and 4) as well as 24 non-Y. enterocolitica strains, belonging to eleven different other Yersinia spp. The strains provided reproducible and unique mass spectra profiles covering a wide molecular mass range (2000 to 30,000 Da). Species-specific and biotype-specific biomarker protein mass patterns were determined for Y. enterocolitica. The defined biomarker mass patterns (SARAMIS SuperSpectrum™) were validated using 117 strains from various Y. enterocolitica bioserotypes in a blind-test. All strains were correctly identified and for all strains the mass spectrometry-based identification scheme yielded identical results compared to a characterization by a combination of biotyping and serotyping. Our study demonstrates that MALDI-TOF-MS is a reliable and powerful tool for the rapid identification of Y. enterocolitica strains to the species level and allows subtyping of strains to the biotype level. Copyright © 2011 Elsevier B.V. All rights reserved.

  19. Distribution of Plasmids in Distinct Leptospira Pathogenic Species.

    Science.gov (United States)

    Wang, Yanzhuo; Zhuang, Xuran; Zhong, Yi; Zhang, Cuicai; Zhang, Yan; Zeng, Lingbing; Zhu, Yongzhang; He, Ping; Dong, Ke; Pal, Utpal; Guo, Xiaokui; Qin, Jinhong

    2015-11-01

    Leptospirosis, caused by pathogenic Leptospira, is a worldwide zoonotic infection. The genus Leptospira includes at least 21 species clustered into three groups--pathogens, non-pathogens, and intermediates--based on 16S rRNA phylogeny. Research on Leptospira is difficult due to slow growth and poor transformability of the pathogens. Recent identification of extrachromosomal elements besides the two chromosomes in L. interrogans has provided new insight into genome complexity of the genus Leptospira. The large size, low copy number, and high similarity of the sequence of these extrachromosomal elements with the chromosomes present challenges in isolating and detecting them without careful genome assembly. In this study, two extrachromosomal elements were identified in L. borgpetersenii serovar Ballum strain 56604 through whole genome assembly combined with S1 nuclease digestion following pulsed-field gel electrophoresis (S1-PFGE) analysis. Further, extrachromosomal elements in additional 15 Chinese epidemic strains of Leptospira, comprising L. borgpetersenii, L. weilii, and L. interrogans, were successfully separated and identified, independent of genome sequence data. Southern blot hybridization with extrachromosomal element-specific probes, designated as lcp1, lcp2 and lcp3-rep, further confirmed their occurrences as extrachromosomal elements. In total, 24 plasmids were detected in 13 out of 15 tested strains, among which 11 can hybridize with the lcp1-rep probe and 11 with the lcp2-rep probe, whereas two can hybridize with the lcp3-rep probe. None of them are likely to be species-specific. Blastp search of the lcp1, lcp2, and lcp3-rep genes with a nonredundant protein database of Leptospira species genomes showed that their homologous sequences are widely distributed among clades of pathogens but not non-pathogens or intermediates. These results suggest that the plasmids are widely distributed in Leptospira species, and further elucidation of their biological

  20. Leptospira species in floodwater during the 2011 floods in the Bangkok Metropolitan Region, Thailand.

    Science.gov (United States)

    Thaipadungpanit, Janjira; Wuthiekanun, Vanaporn; Chantratita, Narisara; Yimsamran, Surapon; Amornchai, Premjit; Boonsilp, Siriphan; Maneeboonyang, Wanchai; Tharnpoophasiam, Prapin; Saiprom, Natnaree; Mahakunkijcharoen, Yuvadee; Day, Nicholas P J; Singhasivanon, Pratap; Peacock, Sharon J; Limmathurotsakul, Direk

    2013-10-01

    Floodwater samples (N = 110) collected during the 2011 Bangkok floods were tested for Leptospira using culture and polymerase chain reaction (PCR); 65 samples were PCR-positive for putatively non-pathogenic Leptospira species, 1 sample contained a putatively pathogenic Leptospira, and 6 samples contained Leptospira clustering phylogenetically with the intermediate group. The low prevalence of pathogenic and intermediate Leptospira in floodwater was consistent with the low number of human leptospirosis cases reported to the Bureau of Epidemiology in Thailand. This study provides baseline information on environmental Leptospira in Bangkok together with a set of laboratory tests that could be readily deployed in the event of future flooding.

  1. Neisseria gonorrhoeae and extended-spectrum cephalosporins in California: surveillance and molecular detection of mosaic penA.

    Science.gov (United States)

    Gose, Severin; Nguyen, Duylinh; Lowenberg, Daniella; Samuel, Michael; Bauer, Heidi; Pandori, Mark

    2013-12-04

    The spread of Neisseria gonorrhoeae strains with mosaic penA alleles and reduced susceptibility to extended-spectrum cephalosporins is a major public health problem. While much work has been performed internationally, little is known about the genetics or molecular epidemiology of N. gonorrhoeae isolates with reduced susceptibility to extended-spectrum cephalosporins in the United States. The majority of N. gonorrhoeae infections are diagnosed without a live culture. Molecular tools capable of detecting markers of extended-spectrum cephalosporin resistance are needed. Urethral N. gonorrhoeae isolates were collected from 684 men at public health clinics in California in 2011. Minimum inhibitory concentrations (MICs) to ceftriaxone, cefixime, cefpodoxime and azithromycin were determined by Etest and categorized according to the U.S. Centers for Disease Control 2010 alert value breakpoints. 684 isolates were screened for mosaic penA alleles using real-time PCR (RTPCR) and 59 reactive isolates were subjected to DNA sequencing of their penA alleles and Neisseria gonorrhoeae multi-antigen sequence typing (NG-MAST). To increase the specificity of the screening RTPCR in detecting isolates with alert value extended-spectrum cephalosporin MICs, the primers were modified to selectively amplify the mosaic XXXIV penA allele. Three mosaic penA alleles were detected including two previously described alleles (XXXIV, XXXVIII) and one novel allele (LA-A). Of the 29 isolates with an alert value extended-spectrum cephalosporin MIC, all possessed the mosaic XXXIV penA allele and 18 were sequence type 1407, an internationally successful strain associated with multi-drug resistance. The modified RTPCR detected the mosaic XXXIV penA allele in urethral isolates and urine specimens and displayed no amplification of the other penA alleles detected in this study. N. gonorrhoeae isolates with mosaic penA alleles and reduced susceptibility to extended-spectrum cephalosporins are currently

  2. Prevalencia de anticuerpos anti-Chlamydia trachomatis y anti-Neisseria gonorrhoeae en grupos de individuos de la población mexicana Prevalence of antibodies against Chlamydia trachomatis and Neisseria gonorrhoeae in Mexican populations

    Directory of Open Access Journals (Sweden)

    María del Carmen Cravioto

    2003-01-01

    Full Text Available OBJETIVO: Estimar la prevalencia de infección por Chlamydia trachomatis (CT y Neisseria gonorrhoeae (NG en grupos de individuos con diferente riesgo para infecciones de transmisión sexual. MATERIAL Y MÉTODOS: Estudio transversal multicéntrico efectuado en el Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, de la Ciudad de México, de enero de 1992 a diciembre de 1993, en el que se estudiaron 945 individuos en edad reproductiva, 585 mujeres y 360 hombres. Según su riesgo para infecciones de transmisión sexual se clasificaron en grupos de alto y bajo riesgo. Los de alto riesgo incluyeron mujeres infértiles con daño tubario, mujeres con embarazo ectópico o aborto, hombres infértiles, pacientes con VIH/SIDA, hombres homo o bisexuales y trabajadoras del sexo comercial (TSC. Los de bajo riesgo: mujeres primigestas, hombres fértiles y mujeres infértiles sin daño tubario. Se determinó en duplicado IgG e IgA anti-NG y anti-CT en suero, por análisis inmunoenzimático, utilizando como antígeno el pili de NG y la fracción L1 de CT. Se calcularon porcentajes. RESULTADOS: En mujeres la prevalencia para NG fue IgG 13.7% e IgA 14.3%, y para CT fue IgG 11.4% e IgA 4.4%. En hombres, NG 3.3% y 13.3%, respectivamente, y para CT 7.2% y 5.5%, respectivamente. En TSC se encontró NG en 31.2 % y 28.4%, respectivamente, y para CT 25.0% y 5.7%, respectivamente. En mujeres con infertilidad por daño tubario, NG 5.6% y 9.8%, respectivamente, y CT 8.4% y 1.4%, respectivamente. En 110 primigestas jóvenes, NG 4.5% y 10.0%, respectivamente, y CT 3.6% y 9.1%, respectivamente. CONCLUSIONES: Estos datos confirman la prevalencia elevada de Neisseria gonorrhoeae y Chlamydia trachomatis en trabajadoras del sexo comercial y en hombres homo/bisexuales, pero no en otros grupos de alto riesgo como las mujeres infértiles, con aborto o embarazo ectópico.OBJECTIVE: To estimate the prevalence of Chlamydia trachomatis (CT and Neisseria gonorrhoeae

  3. Diagnostic aspects of infections with Chlamydia trachomatis, Neisseria gonorrhoeae and herpes simplex virus

    NARCIS (Netherlands)

    J. Ulsen (Josina)

    1994-01-01

    textabstractThe sexually transmitted diseases (STOs) constitute a worldwide problem of major significance in terms of health. economic and social consequences. The most important STOs are Ihe bacterial infections syphilis (causative agent Treponema pal/idum sub·species pallidum), gonorrhoea

  4. Dinámicas de las interacciones de Neisseria meningitidis con las barreras celulares y los efectores inmunes

    Directory of Open Access Journals (Sweden)

    Natalie J. Griffiths

    2009-08-01

    Full Text Available Neisseria meningitidis outer membrane (OM adhesins, Opa and Opc are known to exert significant influence on bacterial adhesion and invasion properties. They are also likely to affect the dynamics of cellular barrier penetration as they target human receptors that are subject to upregulation under inflammatory conditions. As some of the targeted receptors are also expressed on immune cells, it is possible that the OM proteins, when presented on bacteria or in OM vesicle vaccines, have the additional capacity to modulate host immune responses. In our recent studies, in vitro model systems were used to further explore these possibilities. The studies illustrated that the major human receptors targeted by Opa and Opc, i.e. CEACAMs and integrins, when upregulated by inflammatory cytokines, encourage enhanced cellular adhesion, invasion and barrier traversal. Tissue infiltration by fully capsulate bacteria via Opa proteins was also observed for piliated Opa+ meningococci. Other studies indicate that Opc increases meningococcal resistance to serum-mediated killing by binding to the complement regulatory molecule vitronectin. In addition, although adverse immunomodulatory effects have been reported for Opa-expressing gonococci and meningococcal OMVs, our studies indicate that interactions with CD4+ T cell expressed CEACAM1 does not offer immunomodulatory properties to meningococci.

  5. The second nationwide surveillance of the antimicrobial susceptibility of Neisseria gonorrhoeae from male urethritis in Japan, 2012-2013.

    Science.gov (United States)

    Hamasuna, Ryoichi; Yasuda, Mitsuru; Ishikawa, Kiyohito; Uehara, Shinya; Hayami, Hiroshi; Takahashi, Satoshi; Matsumoto, Tetsuro; Yamamoto, Shingo; Minamitani, Shinichi; Watanabe, Akira; Iwata, Satoshi; Kaku, Mitsuo; Kadota, Junichi; Sunakawa, Keisuke; Sato, Junko; Hanaki, Hideaki; Tsukamoto, Taiji; Kiyota, Hiroshi; Egawa, Shin; Tanaka, Kazushi; Arakawa, Soichi; Fujisawa, Masato; Kumon, Hiromi; Kobayashi, Kanao; Matsubara, Akio; Naito, Seiji; Kuroiwa, Kentaro; Hirayama, Hideo; Narita, Harunori; Hosobe, Takahide; Ito, Shin; Ito, Kenji; Kawai, Shuichi; Ito, Masayasu; Chokyu, Hirofumi; Matsumura, Masaru; Yoshioka, Masaru; Uno, Satoshi; Monden, Koichi; Takayama, Kazuo; Kaji, Shinichi; Kawahara, Motoshi; Sumii, Toru; Kadena, Hitoshi; Yamaguchi, Takamasa; Maeda, Shinichi; Nishi, Shohei; Nishimura, Hirofumi; Shirane, Takeshi; Yoh, Mutsumasa; Akiyama, Kikuo; Imai, Toshio; Kano, Motonori

    2015-05-01

    Worldwide, the most important concern in the treatment of sexually transmitted infections is the increase in antimicrobial resistant Neisseria gonorrhoeae strains including resistance to cephalosporins, penicillins, fluoroquinolones or macrolides. To investigate the trends of antimicrobial susceptibility among N. gonorrhoeae strains isolated from male patients with urethritis, a Japanese surveillance committee conducted the second nationwide surveillance study. Urethral discharge was collected from male patients with urethritis at 26 medical facilities from March 2012 to January 2013. Of the 151 specimens, 103 N. gonorrhoeae strains were tested for susceptibility to 20 antimicrobial agents. None of the strains was resistant to ceftriaxone, but the minimum inhibitory concentration (MIC) 90% of ceftriaxone increased to 0.125 μg/ml, and 11 (10.7%) strains were considered less susceptible with an MIC of 0.125 μg/ml. There were 11 strains resistant to cefixime, and the MICs of these strains were 0.5 μg/ml. The distributions of the MICs of fluoroquinolones, such as ciprofloxacin, levofloxacin and tosufloxacin, were bimodal. Sitafloxacin, a fluoroquinolone, showed strong activity against all strains, including strains resistant to other three fluoroquinolones, such as ciprofloxacin, levofloxacin and tosufloxacin. The azithromycin MICs in 2 strains were 1 μg/ml. Copyright © 2015 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

  6. Short-term and long-term antibody response by mice after immunization against Neisseria meningitidis B or diphtheria toxoid

    Directory of Open Access Journals (Sweden)

    G.P. Silva

    2013-02-01

    Full Text Available Serogroup B Neisseria meningitidis (MenB is a major cause of invasive disease in early childhood worldwide. The only MenB vaccine available in Brazil was produced in Cuba and has shown unsatisfactory efficacy when used to immunize millions of children in Brazil. In the present study, we compared the specific functional antibody responses evoked by the Cuban MenB vaccine with a standard vaccine against diphtheria (DTP: diphtheria, tetanus, pertussis after primary immunization and boosting of mice. The peak of bactericidal and opsonic antibody titers to MenB and of neutralizing antibodies to diphtheria toxoid (DT was reached after triple immunization with the MenB vaccine or DTP vaccine, respectively. However, 4 months after immunization, protective DT antibody levels were present in all DTP-vaccinated mice but in only 20% of the mice immunized against MenB. After 6 months of primary immunization, about 70% of animals still had protective neutralizing DT antibodies, but none had significant bactericidal antibodies to MenB. The booster doses of DTP or MenB vaccines produced a significant antibody recall response, suggesting that both vaccines were able to generate and maintain memory B cells during the period studied (6 months post-triple immunization. Therefore, due to the short duration of serological memory induced by the MenB vaccine (VA-MENGOC-BC® vaccine, its use should be restricted to outbreaks of meningococcal disease.

  7. Could the multicomponent meningococcal serogroup B vaccine (4CMenB) control Neisseria meningitidis capsular group X outbreaks in Africa?

    Science.gov (United States)

    Hong, Eva; Giuliani, Marzia Monica; Deghmane, Ala-Eddine; Comanducci, Maurizio; Brunelli, Brunella; Dull, Peter; Pizza, Mariagrazia; Taha, Muhamed-Kheir

    2013-02-04

    A new vaccine, 4CMenB, is composed of surface proteins of Neisseria meningitidis and is aimed to target serogroup B (MenB) isolates. The vaccine components are present in meningococcal isolates of other serogroups allowing potential use against meningococcal isolates belonging to non-B serogroups. Isolates of serogroup X (MenX) have been emerged in countries of the African meningitis belt. 4CMenB may offer a vaccine strategy against these isolates as there is no available capsule-based vaccine against MenX. We used the Meningococcal Antigen Typing System (MATS) to determine presence, diversity and levels of expression of 4CMenB antigens among 9 MenX isolates from several African countries in order to estimate the potential coverage of MenX by the 4CMenB vaccine. We performed bactericidal assays against these isolates, using pooled sera from 4CMenB-vaccinated infants, adolescents and adults. The African MenX isolates belonged to the same genotype but showed variation in the vaccine antigens. MATS data and bactericidal assays suggest coverage of the 9 African MenX isolates by 4CMenB but not of two unrelated MenX isolates from France. 4CMenB vaccine can be considered for further investigation to control MenX outbreaks in Africa. Copyright © 2012 Elsevier Ltd. All rights reserved.

  8. Genital Chlamydia trachomatis and Neisseria gonorrhoeae infections among women in sub-Saharan Africa: A structured review.

    Science.gov (United States)

    Dubbink, Jan Henk; Verweij, Stephan P; Struthers, Helen E; Ouburg, Sander; McIntyre, James A; Morré, Servaas A; Peters, Remco Ph

    2018-01-01

    Chlamydia trachomatis and Neisseria gonorrhoeae constitute major public health problems among women, but the burden of infection in sub-Saharan Africa is poorly documented. We conducted a structured review of the prevalence and incidence of genital, oral and anal C. trachomatis and N. gonorrhoeae infection in women in sub-Saharan Africa. We searched Medline, EMBASE and Web of Science over a 10-year period for studies on epidemiology of genital, oral and anal chlamydial infection and gonorrhoea in women in all countries of sub-Saharan Africa. We assessed geographic and demographic differences in prevalence and incidence of infection; weighted mean prevalence estimates were calculated with a random-effect model. A total of 102 study results were included, with data available for 24/49 of sub-Saharan countries. The weighted prevalence of chlamydial infection was lower among women in community-based studies (3.9%; 95% CI: 2.9-5.1%) than for women recruited at primary healthcare facilities (6.0%; 95% CI: 4.2-8.4%, p sub-Saharan Africa. Better control strategies are warranted to reduce the burden of infection and to prevent long-term complications of these infections.

  9. Should urologists care for the pharyngeal infection of Neisseria gonorrhoeae or Chlamydia trachomatis when we treat male urethritis?

    Science.gov (United States)

    Hamasuna, Ryoichi; Takahashi, Satoshi; Uehara, Shinya; Matsumoto, Tetsuro

    2012-06-01

    Detection of Neisseria gonorrhoeae (NG) or Chlamydia trachomatis (CT) from the pharynx of women or men is not uncommon. However, there is no recommendation how urologists should care for the pharyngeal infection of men with urethritis in Japan. The aim of this study is to clarify the prevalence of NG or CT infection in the pharynx of men and to show a recommendation for urologists. The Japanese reports about the detection of NG or CT from the pharynx or the oral cavity of men in Japan are reviewed in the literature from 1990 to 2011. The prevalence of NG or CT in the pharynx was 4% or 6% in men who attended clinics, and 20% or 6% in men who were positive for NG or CT from genital specimens, respectively. Single 1-g dose ceftriaxone was recommended to treat pharyngeal NG, but no evidence was found for pharyngeal CT. There was not enough evidence for recommendation. However, when men with urethritis only caused by NG or CT are treated through the guideline of the Japanese Society of Sexually Transmitted Infection, we do not think additional tests or treatment for the pharynx are needed when a single 1-g dose ceftriaxone for gonococcal urethritis or a single 1- or 2- g dose azithromycin is prescribed for chlamydial urethritis in Japan.

  10. Meningitis caused by Neisseria Meningitidis, Hemophilus Influenzae Type B and Streptococcus Pneumoniae during 2005–2012 in Turkey

    Science.gov (United States)

    Ceyhan, Mehmet; Gürler, Nezahat; Ozsurekci, Yasemin; Keser, Melike; Aycan, Ahmet Emre; Gurbuz, Venhar; Salman, Nuran; Camcioglu, Yildiz; Dinleyici, Ener Cagri; Ozkan, Sengul; Sensoy, Gulnar; Belet, Nursen; Alhan, Emre; Hacimustafaoglu, Mustafa; Celebi, Solmaz; Uzun, Hakan; Faik Oner, Ahmet; Kurugol, Zafer; Ali Tas, Mehmet; Aygun, Denizmen; Oncel, Eda Karadag; Celik, Melda; Yasa, Olcay; Akin, Fatih; Coşkun, Yavuz

    2014-01-01

    Successful vaccination policies for protection from bacterial meningitis are dependent on determination of the etiology of bacterial meningitis. Cerebrospinal fluid (CSF) samples were obtained prospectively from children from 1 month to ≤ 18 years of age hospitalized with suspected meningitis, in order to determine the etiology of meningitis in Turkey. DNA evidence of Neisseria meningitidis (N. meningitidis), Streptococcus pneumoniae (S. pneumoniae), and Hemophilus influenzae type b (Hib) was detected using multiplex polymerase chain reaction (PCR). In total, 1452 CSF samples were evaluated and bacterial etiology was determined in 645 (44.4%) cases between 2005 and 2012; N. meningitidis was detected in 333 (51.6%), S. pneumoniae in 195 (30.2%), and Hib in 117 (18.1%) of the PCR positive samples. Of the 333 N. meningitidis positive samples 127 (38.1%) were identified as serogroup W-135, 87 (26.1%) serogroup B, 28 (8.4%) serogroup A and 3 (0.9%) serogroup Y; 88 (26.4%) were non-groupable. As vaccines against the most frequent bacterial isolates in this study are available and licensed, these results highlight the need for broad based protection against meningococcal disease in Turkey. PMID:25483487

  11. Determination of in vitro synergy for dual antimicrobial therapy against resistant Neisseria gonorrhoeae using Etest and agar dilution.

    Science.gov (United States)

    Wind, Carolien M; de Vries, Henry J C; van Dam, Alje P

    2015-03-01

    In response to antimicrobial resistance of Neisseria gonorrhoeae to last-resort extended-spectrum cephalosporins, combination therapy of azithromycin+ceftriaxone is now recommended. Dual therapy can be effective to treat monoresistant strains as well as multidrug-resistant strains, preferably employing the effect of in vitro synergy. As reports on in vitro synergy of azithromycin+ceftriaxone in N. gonorrhoeae are conflicting, in this study an evaluation of this combination was performed using a cross-wise Etest method and agar dilution. Synergy was defined as a fractional inhibitory concentration index (FICI) of ≤0.5. To identify other dual treatment options for gonorrhoea, in vitro synergy was evaluated for 65 dual antimicrobial combinations using Etest. Azithromycin, cefixime, ceftriaxone, colistin, ertapenem, fosfomycin, gentamicin, minocycline, moxifloxacin, rifampicin, spectinomycin and tigecycline were screened for synergy in all possible combinations. No synergy or antagonism was found for any of the 65 combinations. The geometric mean FICI ranged from 0.82 to 2.00. The mean FICI of azithromycin+ceftriaxone was 1.18 (Etest) and 0.55 (agar dilution). The difference between both methods did not result in a difference in interpretation of synergy. Ceftriaxone-resistant strain F89 was tested in all combinations and no synergy was found for any of them. Most importantly, the ceftriaxone minimum inhibitory concentration of F89 was not decreased below the breakpoint with any concentration of azithromycin. Copyright © 2014 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.

  12. Chlamydia trachomatis, Neisseria gonorrhoeae, and Trichomonas vaginalis screening and treatment of pregnant women in Port-au-Prince, Haiti.

    Science.gov (United States)

    Bristow, Claire C; Mathelier, Patricia; Ocheretina, Oksana; Benoit, Daphne; Pape, Jean W; Wynn, Adriane; Klausner, Jeffrey D

    2017-10-01

    In Haiti, routine screening for Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG), and Trichomonas vaginalis (TV) among pregnant women is not conducted; yet these sexually transmitted infections (STIs) are associated with adverse birth and newborn health outcomes. We aimed to assess the acceptability and feasibility of screening and the prevalence of STIs among pregnant women in Port-au-Prince, Haiti. Pregnant women of at least 18 years of age who attend Haitian Study Group for Kaposi's sarcoma and Opportunistic Infections (GHESKIO) clinics in Port-au-Prince, Haiti provided self-collected vaginal swab specimens. Laboratory testing was done with Xpert® CT/NG and Xpert® TV. The results of this study showed that of the 322 pregnant women who visited GHESKIO for their regular scheduled appointments, 300 (93.2%) consented for CT, NG, and TV testing. Of those, 107 women (35.7%) tested positive for at least one STI. There were 42 (14.7%) cases of CT, 8 (2.8%) NG, and 83 (29.0%) TV infections. Most infections were treated - 122 of 133 (91.7%). In summary, we found that it was highly acceptable and feasible to implement CT, NG, and TV screening among pregnant women in Port-au-Prince, Haiti. We found high prevalence of STIs among pregnant women, which suggest that STI screening in this population may be warranted.

  13. Molecular characterization of Neisseria gonorrhoeae isolates in Almaty, Kazakhstan, by VNTR analysis, Opa-typing and NG-MAST.

    Science.gov (United States)

    Kushnir, Anastasiya V; Muminov, Talgat A; Bayev, Assylzhan I; Khrapov, Evgeny A; Filipenko, Maxim L

    2012-04-01

    In the present study, new variable number tandem repeats (VNTR) loci in the Neisseria gonorrhoeae genome were identified in silico. VNTR analysis scheme using PCR and agarose or polyacrylamide gel electrophoresis was developed based on nine VNTR loci with various degrees of polymorphism. The method was used to genotype a collection of 48 isolates, obtained from patients with gonorrhea in Almaty, Kazakhstan during the period from December 2008 to November 2009. This collection of isolates was also characterized by the opa-typing and multiantigen sequence typing (NG-MAST). The discriminatory power of the VNTR analysis translated by Hunter-Gaston Discrimination Index (HGDI) was similar to that of opa typing (HGDI=0.98 versus 0.97) and slightly higher than that of NG-MAST (HDGI=0.95). The adjusted Rand (AR) coefficients and Wallace coefficients showed that the overall concordance between the typing methods was not high. VNTR analysis described here is simple, inexpensive, easy to interpret, and it would be reliable for the comparison of data obtained in different laboratories. The proposed VNTR loci might be used for epidemiological studies of gonococcal infections. Copyright © 2012 Elsevier B.V. All rights reserved.

  14. Antimicrobial Resistance Expressed by Neisseria gonorrhoeae: A Major Global Public Health Problem in the 21st Century.

    Science.gov (United States)

    Unemo, Magnus; Del Rio, Carlos; Shafer, William M

    2016-06-01

    Neisseria gonorrhoeae is a strictly human pathogen that is typically transmitted by sexual contact. The associated disease gonorrhea has plagued humankind for thousands of years, with a current estimated incidence of 78 million cases per year. Advances in antimicrobial discovery in the 1920s and 1930s leading to the discovery of sulfonamides and penicillin begun the era of effective antimicrobial treatment of gonorrhea. Unfortunately, the gonococcus developed decreased susceptibility or even resistance to these initially employed antibiotics, a trend that continued over subsequent decades with each new antibiotic that was brought into clinical practice. As this pattern of resistance has continued into the 21st century, there is now reason for great concern, especially in an era when few new antibiotics have prospects for use as treatment of gonorrhea. Here, we review the history of gonorrhea treatment regimens and gonococcal resistance to antibiotics, the mechanisms of resistance, resistance monitoring schemes that exist in different international settings, global responses to the challenge of resistance, and prospects for future treatment regimens in the 21st century.

  15. [Surveillance of Neisseria meningitidis in Argentina, 1993-2005: distribution of serogroups, serotypes and serosubtypes isolated from invasive disease].

    Science.gov (United States)

    Chiávetta, L; Chávez, E; Ruzic, A; Mollerach, M; Regueira, M

    2007-01-01

    Neisseria meningitidis is an important cause of meningitis, bacteremia and septic shock syndrome. We herein present the distribution of serogroups, serotypes and serosubtypes of 2244 isolates of N. meningitidis from patients with meningitis or meningococcemia, received within the period 1993-2005, in the National Reference Laboratory, INEI-ANLIS "Dr. Carlos G. Malbrán", from 33 Argentine hospitals that are included in a National Network devoted to for the study of bacterial meningitis. Between 1993-1995, serogroup B was prevalent (66%) whereas in the period from 1995-2001, serogroup C prevailed (65%). However, following but after that period, the prevalence of serogroup B was recovered. In the last 5 years of the studied period, the serogroups Y and W135 represented as a whole a 15.6% as a whole whereas up to the year 2000 during the first 6 years they accounted for it was of 4.7%. Higher diversity in the distribution of serotypes and serosubtypes was observed within serogroup B. The nonsubtypable isolates throughout the period of study represented the 52.8%, this high percentage demonstrates the limited capacity of the serotyping for the determination of meningococcal/meningococcus subtypes. of meningococco.

  16. Whole-Genome Characterization of Epidemic Neisseria meningitidis Serogroup C and Resurgence of Serogroup W, Niger, 2015

    Science.gov (United States)

    Kretz, Cecilia B.; Retchless, Adam C.; Sidikou, Fati; Issaka, Bassira; Ousmane, Sani; Schwartz, Stephanie; Tate, Ashley H.; Pana, Assimawè; Njanpop-Lafourcade, Berthe-Marie; Nzeyimana, Innocent; Nse, Ricardo Obama; Deghmane, Ala-Eddine; Hong, Eva; Brynildsrud, Ola Brønstad; Novak, Ryan T.; Meyer, Sarah A.; Oukem-Boyer, Odile Ouwe Missi; Ronveaux, Olivier; Caugant, Dominique A.; Taha, Muhamed-Kheir

    2016-01-01

    In 2015, Niger reported the largest epidemic of Neisseria meningitidis serogroup C (NmC) meningitis in sub-Saharan Africa. The NmC epidemic coincided with serogroup W (NmW) cases during the epidemic season, resulting in a total of 9,367 meningococcal cases through June 2015. To clarify the phylogenetic association, genetic evolution, and antibiotic determinants of the meningococcal strains in Niger, we sequenced the genomes of 102 isolates from this epidemic, comprising 81 NmC and 21 NmW isolates. The genomes of 82 isolates were completed, and all 102 were included in the analysis. All NmC isolates had sequence type 10217, which caused the outbreaks in Nigeria during 2013–2014 and for which a clonal complex has not yet been defined. The NmC isolates from Niger were substantially different from other NmC isolates collected globally. All NmW isolates belonged to clonal complex 11 and were closely related to the isolates causing recent outbreaks in Africa. PMID:27649262

  17. Cervical Infection with Herpes simplex Virus, Chlamydia trachomatis, and Neisseria gonorrhoeae among Symptomatic Women, Dubai, UAE: A Molecular Approach

    Directory of Open Access Journals (Sweden)

    Davood Mehrabani

    2014-01-01

    Full Text Available Tragically, genital tract infections are still a major public health problem in many regions. This study was undertaken to determine the prevalence of cervical infection with Herpes simplex virus (HSV, Chlamydia trachomatis (CT, and Neisseria gonorrhoeae (NG among married women referring to Iranian Hospital, Dubai, UAE. In a retrospective cross-sectional survey, 201 female patients aged 16–80 years who referred to the Obstetrics and Gynecology Department of Iranian Hospital, Dubai, UAE, in 2010 were enrolled. The patients were categorized into three age groups: 15–30 (group I, 31–40 (group II, and ≥41 years old (group III. A cervical swab sample was collected from each woman and the prevalence of cervical infection with HSV, CT, and NG was determined by PCR method. HSV, CT, and NG were detected in 6.5%, 10.4%, and 5.5% of swab samples, respectively. Regarding age, a significant difference was noticed for prevalence of NG and HSV between groups I and III. Because of public health importance of sexual transmitted diseases (STDs, their long-lasting impact on quality of life, and their economic burden, preventing measures and education of women seem necessary.

  18. Meningococcal Disease Caused by Neisseria meningitidis Serogroup B Serotype 4 in São Paulo, Brazil, 1990 to 1996

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    Sacchi Claudio Tavares

    1998-01-01

    Full Text Available A large epidemic of serogroup B meningococcal disease (MD, has been occurring in greater São Paulo, Brazil, since 1988.21 A Cuban-produced vaccine, based on outer-membrane-protein (OMP from serogroup B: serotype 4: serosubtype P1.15 (B:4:P1.15 Neisseria meningitidis, was given to about 2.4 million children aged from 3 months to 6 years during 1989 and 1990. The administration of vaccine had little or no measurable effects on this outbreak. In order to detect clonal changes that could explain the continued increase in the incidence of disease after the vaccination, we serotyped isolates recovered between 1990 and 1996 from 834 patients with systemic disease. Strains B:4:P1.15, which was detected in the area as early as 1977, has been the most prevalent phenotype since 1988. These strains are still prevalent in the area and were responsible for about 68% of 834 serogroup B cases in the last 7 years. We analyzed 438 (52% of these strains by restriction fragment length polymorphism (RFLPs of rRNA genes (ribotyping. The most frequent pattern obtained was referred to as Rb1 (68%. We concluded that the same clone of B:4:P1.15-Rb1 strains was the most prevalent strain and responsible for the continued increase of incidence of serogroup B MD cases in greater São Paulo during the last 7 years in spite of the vaccination trial.

  19. Clonal Distribution of Disease-Associated and Healthy Carrier Isolates of Neisseria meningitidis between 1983 and 2005 in Cuba ▿

    Science.gov (United States)

    Climent, Yanet; Yero, Daniel; Martinez, Isabel; Martín, Alejandro; Jolley, Keith A.; Sotolongo, Franklin; Maiden, Martin C. J.; Urwin, Rachel; Pajón, Rolando

    2010-01-01

    In response to epidemic levels of serogroup B meningococcal disease in Cuba during the 1980s, the VA-MENGOC-BC vaccine was developed and introduced into the National Infant Immunization Program in 1991. Since then the incidence of meningococcal disease in Cuba has returned to the low levels recorded before the epidemic. A total of 420 Neisseria meningitidis strains collected between 1983 and 2005 in Cuba were analyzed by multilocus sequence typing (MLST). The set of strains comprised 167 isolated from disease cases and 253 obtained from healthy carriers. By MLST analysis, 63 sequence types (STs) were identified, and 32 of these were reported to be a new ST. The Cuban isolates were associated with 12 clonal complexes; and the most common were ST-32 (246 isolates), ST-53 (86 isolates), and ST-41/44 (36 isolates). This study also showed that the application of VA-MENGOC-BC, the Cuban serogroup B and C vaccine, reduced the frequency and diversity of hypervirulent clonal complexes ST-32 (vaccine serogroup B type-strain) and ST-41/44 and also affected other lineages. Lineages ST-8 and ST-11 were no longer found during the postvaccination period. The vaccine also affected the genetic composition of the carrier-associated meningococcal isolates. The number of carrier isolates belonging to hypervirulent lineages decreased significantly after vaccination, and ST-53, a sequence type common in carriers, became the predominant ST. PMID:20042619

  20. Restriction endonucleases from invasive Neisseria gonorrhoeae cause double-strand breaks and distort mitosis in epithelial cells during infection.

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    Linda Weyler

    Full Text Available The host epithelium is both a barrier against, and the target for microbial infections. Maintaining regulated cell growth ensures an intact protective layer towards microbial-induced cellular damage. Neisseria gonorrhoeae infections disrupt host cell cycle regulation machinery and the infection causes DNA double strand breaks that delay progression through the G2/M phase. We show that intracellular gonococci upregulate and release restriction endonucleases that enter the nucleus and damage human chromosomal DNA. Bacterial lysates containing restriction endonucleases were able to fragment genomic DNA as detected by PFGE. Lysates were also microinjected into the cytoplasm of cells in interphase and after 20 h, DNA double strand breaks were identified by 53BP1 staining. In addition, by using live-cell microscopy and NHS-ester stained live gonococci we visualized the subcellular location of the bacteria upon mitosis. Infected cells show dysregulation of the spindle assembly checkpoint proteins MAD1 and MAD2, impaired and prolonged M-phase, nuclear swelling, micronuclei formation and chromosomal instability. These data highlight basic molecular functions of how gonococcal infections affect host cell cycle regulation, cause DNA double strand breaks and predispose cellular malignancies.

  1. Restriction endonucleases from invasive Neisseria gonorrhoeae cause double-strand breaks and distort mitosis in epithelial cells during infection.

    Science.gov (United States)

    Weyler, Linda; Engelbrecht, Mattias; Mata Forsberg, Manuel; Brehwens, Karl; Vare, Daniel; Vielfort, Katarina; Wojcik, Andrzej; Aro, Helena

    2014-01-01

    The host epithelium is both a barrier against, and the target for microbial infections. Maintaining regulated cell growth ensures an intact protective layer towards microbial-induced cellular damage. Neisseria gonorrhoeae infections disrupt host cell cycle regulation machinery and the infection causes DNA double strand breaks that delay progression through the G2/M phase. We show that intracellular gonococci upregulate and release restriction endonucleases that enter the nucleus and damage human chromosomal DNA. Bacterial lysates containing restriction endonucleases were able to fragment genomic DNA as detected by PFGE. Lysates were also microinjected into the cytoplasm of cells in interphase and after 20 h, DNA double strand breaks were identified by 53BP1 staining. In addition, by using live-cell microscopy and NHS-ester stained live gonococci we visualized the subcellular location of the bacteria upon mitosis. Infected cells show dysregulation of the spindle assembly checkpoint proteins MAD1 and MAD2, impaired and prolonged M-phase, nuclear swelling, micronuclei formation and chromosomal instability. These data highlight basic molecular functions of how gonococcal infections affect host cell cycle regulation, cause DNA double strand breaks and predispose cellular malignancies.

  2. Molecular Diagnosis of Pathogenic Sporothrix Species.

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    Anderson Messias Rodrigues

    2015-12-01

    Full Text Available Sporotrichosis is a chronic (subcutaneous infection caused by thermodimorphic fungi in the order, Ophiostomatales. These fungi are characterized by major differences in routes of transmission, host predilections, species virulence, and susceptibilities to antifungals. Sporothrix species emerge in the form of outbreaks. Large zoonoses and sapronoses are ongoing in Brazil and China, respectively. Current diagnostic methods based on morphology and physiology are inaccurate due to closely related phenotypes with overlapping components between pathogenic and non-pathogenic Sporothrix. There is a critical need for new diagnostic tools that are specific, sensitive, and cost-effective.We developed a panel of novel markers, based on calmodulin (CAL gene sequences, for the large-scale diagnosis and epidemiology of clinically relevant members of the Sporothrix genus, and its relative, Ophiostoma. We identified specific PCR-based markers for S. brasiliensis, S. schenckii, S. globosa, S. mexicana, S. pallida, and O. stenoceras. We employed a murine model of disseminated sporotrichosis to optimize a PCR assay for detecting Sporothrix in clinical specimens.Primer-BLAST searches revealed candidate sequences that were conserved within a single species. Species-specific primers showed no significant homology with human, mouse, or microorganisms outside the Sporothrix genus. The detection limit was 10-100 fg of DNA in a single round of PCR for identifying S. brasiliensis, S. schenckii, S. globosa, S. mexicana, and S. pallida. A simple, direct PCR assay, with conidia as a source of DNA, was effective for rapid, low-cost genotyping. Samples from a murine model of disseminated sporotrichosis confirmed the feasibility of detecting S. brasiliensis and S. schenckii DNA in spleen, liver, lungs, heart, brain, kidney, tail, and feces of infected animals.This PCR-based method could successfully detect and identify a single species in samples from cultures and from clinical

  3. Molecular Diagnosis of Pathogenic Sporothrix Species

    Science.gov (United States)

    Rodrigues, Anderson Messias; de Hoog, G. Sybren; de Camargo, Zoilo Pires

    2015-01-01

    Background Sporotrichosis is a chronic (sub)cutaneous infection caused by thermodimorphic fungi in the order, Ophiostomatales. These fungi are characterized by major differences in routes of transmission, host predilections, species virulence, and susceptibilities to antifungals. Sporothrix species emerge in the form of outbreaks. Large zoonoses and sapronoses are ongoing in Brazil and China, respectively. Current diagnostic methods based on morphology and physiology are inaccurate due to closely related phenotypes with overlapping components between pathogenic and non-pathogenic Sporothrix. There is a critical need for new diagnostic tools that are specific, sensitive, and cost-effective. Methodology We developed a panel of novel markers, based on calmodulin (CAL) gene sequences, for the large-scale diagnosis and epidemiology of clinically relevant members of the Sporothrix genus, and its relative, Ophiostoma. We identified specific PCR-based markers for S. brasiliensis, S. schenckii, S. globosa, S. mexicana, S. pallida, and O. stenoceras. We employed a murine model of disseminated sporotrichosis to optimize a PCR assay for detecting Sporothrix in clinical specimens. Results Primer-BLAST searches revealed candidate sequences that were conserved within a single species. Species-specific primers showed no significant homology with human, mouse, or microorganisms outside the Sporothrix genus. The detection limit was 10–100 fg of DNA in a single round of PCR for identifying S. brasiliensis, S. schenckii, S. globosa, S. mexicana, and S. pallida. A simple, direct PCR assay, with conidia as a source of DNA, was effective for rapid, low-cost genotyping. Samples from a murine model of disseminated sporotrichosis confirmed the feasibility of detecting S. brasiliensis and S. schenckii DNA in spleen, liver, lungs, heart, brain, kidney, tail, and feces of infected animals. Conclusions This PCR-based method could successfully detect and identify a single species in samples

  4. Prevalencia de infecciones por Chlamydia trachomatis y Neisseria gonorrhoeae en adolescentes de colegios de la provincia de Sabana Centro, Cundinamarca, Colombia

    OpenAIRE

    María Cecilia Paredes; Yenny Milena Gómez; Ana Marcela Torres; Marcela Fernández; María Belén Tovar

    2015-01-01

    Introducción. Las infecciones por Chlamydia trachomatis y Neisseria gonorrhoeae son las dos infecciones bacterianas de transmisión sexual más frecuentes en el mundo, principalmente en menores de 25 años, en cuya salud sexual, reproductiva y materno-infantil producen secuelas. Objetivo. Estimar la prevalencia de las infecciones por C. trachomatis y N. gonorrhoeae entre adolescentes en colegios de la provincia de Sabana Centro, Cundinamarca, Colombia. Materiales y métodos. Se hizo un estu...

  5. Type I interferon induction by Neisseria gonorrhoeae: Dual requirement of cyclic GMP-AMP synthase and Toll-like receptor 4

    OpenAIRE

    Andrade, Warrison A.; Agarwal, Sarika; Mo, Shunyan; Shaffer, Scott A.; Dillard, Joseph P.; Schmidt, Tobias; Hornung, Veit; Fitzgerald, Katherine A.; Kurt-Jones, Evelyn A.; Golenbock, Douglas T.

    2016-01-01

    The innate immune system is the first line of defense against Neisseria gonorrhoeae (GC). Exposure of cells to GC lipooligosaccharides induces a strong immune response, leading to type I interferon (IFN) production via TLR4/MD-2. In addition to living freely in the extracellular space, GC can invade the cytoplasm to evade detection and elimination. Double-stranded DNA introduced into the cytosol binds and activates the enzyme cyclic-GMP-AMP synthase (cGAS), which produces 2′3′-cGAMP and trigg...

  6. Inhibition of the dapE-Encoded N-Succinyl-L,L-diaminopimelic Acid Desuccinylase from Neisseria meningitidis by L-Captopril

    OpenAIRE

    Starus, Anna; Nocek, Boguslaw; Bennett, Brian; Larrabee, James A.; Shaw, Daniel L.; Sae-Lee, Wisath; Russo, Marie T.; Gillner, Danuta M.; Makowska-Grzyska, Magdalena; Joachimiak, Andrzej; Holz, Richard C.

    2015-01-01

    Binding of the competitive inhibitor L-captopril to the dapE-encoded N-succinyl-L,L-diaminopimelic acid desuccinylase from Neisseria meningitidis (NmDapE) was examined by kinetic, spectroscopic, and crystallographic methods. L-Captopril, an angiotensin-converting enzyme (ACE) inhibitor, was previously shown to be a potent inhibitor of the DapE from Haemophilus influenzae (HiDapE) with an IC50 of 3.3 μM and a measured Ki of 1.8 μM and displayed a dose-responsive antibiotic activity toward Esch...

  7. Vigilancia de Neisseria meningitidis en Argentina, 1993-2005: distribución de serogrupos, serotipos y serosubtipos causantes de enfermedad invasiva

    OpenAIRE

    Chiavetta, L.; Chávez, E.; Ruzic, A.; Mollerach, M.; Regueira, M.

    2007-01-01

    Neisseria meningitidis es agente causal de enfermedades severas como meningitis, bacteriemia y síndrome de shock séptico. Se presenta la distribución en serogrupos, serotipos y serosubtipos de 2244 aislamientos de N. meningitidis obtenidos de cuadros de meningitis y/o meningococcemia durante el período 1993-2005 y analizados en el Laboratorio Nacional de Referencia del INEI-ANLIS "Dr. Carlos G. Malbrán". Estos aislamientos eran provenientes de 33 hospitales de todo el país, conformados en una...

  8. Evaluation of the new AmpliSens multiplex real-time PCR assay for simultaneous detection of Neisseria gonorrhoeae, Chlamydia trachomatis, Mycoplasma genitalium, and Trichomonas vaginalis.

    Science.gov (United States)

    Rumyantseva, Tatiana; Golparian, Daniel; Nilsson, Christian S; Johansson, Emma; Falk, My; Fredlund, Hans; Van Dam, Alje; Guschin, Alexander; Unemo, Magnus

    2015-10-01

    In this study, we performed an evaluation of the new CE-marked multiplex real-time AmpliSens N.gonorrhoeae/C.trachomatis/M.genitalium/T.vaginalis-MULTIPRIME-FRT PCR assay compared to APTIMA tests, i.e., APTIMA COMBO 2 assay, APTIMA Trichomonas vaginalis assay (FDA-approved), and two different APTIMA Mycoplasma genitalium assays (research use only; one of them only used for discrepancy analysis). Vaginal swabs (n = 209) and first-void urine (FVU) specimens from females (n = 498) and males (n = 554), consecutive attendees (n = 1261) at a dermatovenerological clinic in Sweden, were examined. The sensitivity of the AmpliSens PCR assay for detection of C. trachomatis (6.3% prevalence), M. genitalium (5.7% prevalence), N. gonorrhoeae (0.3% prevalence), and T. vaginalis (0.08% prevalence) was 97.5% (95% confidence interval (CI): 91.2-99.6%), 81.9% (95% CI: 70.7-89.7%), 100% (95% CI: 40.2-100%) and 100% (95% CI: 16.5-100%), respectively. The specificity of the AmpliSens PCR assay was 100% (95% CI: 99.6-100%) for all agents. The analytical sensitivity and specificity for N. gonorrhoeae detection was excellent, i.e., 55 international gonococcal strains detected and 135 isolates of 13 non-gonococcal Neisseria species were negative. In conclusion, the multiplex real-time AmpliSens N.gonorrhoeae/C.trachomatis/M.genitalium/T.vaginalis-MULTIPRIME-FRT PCR assay demonstrated high sensitivity and excellent specificity for the detection of C. trachomatis, N. gonorrhoeae, and T. vaginalis, and excellent specificity but suboptimal sensitivity for M. genitalium detection. © 2015 APMIS. Published by John Wiley & Sons Ltd.

  9. Recombinant outer membrane secretin PilQ(406-770) as a vaccine candidate for serogroup B Neisseria meningitidis.

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    Haghi, Fakhri; Peerayeh, Shahin Najar; Siadat, Seyed Davar; Zeighami, Habib

    2012-02-21

    Secretin PilQ is an antigenically conserved outer membrane protein which is present on most meningococci. This protein naturally expressed at high levels and is essential for meningococcal pilus expression at the cell surface. A 1095 bp fragment of C-terminal of secretin pilQ from serogroup B Neisseria meningitidis was cloned into prokaryotic expression vector pET-28a. Recombinant protein was overexpressed with IPTG and affinity-purified by Ni-NTA agarose. BALB/c mice were immunized subcutaneously with purified rPilQ(406-770) mixed with Freund's adjuvant. Serum antibody responses to serogroups A and B N. meningitidis whole cells or purified rPilQ(406-770) and functional activity of antibodies were determined by ELISA and SBA, respectively. The output of rPilQ(406-770) was approximately 50% of the total bacterial proteins. Serum IgG responses were significantly increased in immunized group with PilQ(406-770) mixed with Freund's adjuvant in comparison with control groups. Antisera produced against rPilQ(406-770) demonstrated strong surface reactivity to serogroups A and B N. meningitidis tested by whole-cell ELISA. Surface reactivity to serogroup B N. meningitidis was higher than serogroup A. The sera from PilQ(406-770) immunized animals were strongly bactericidal against serogroups A and B. These results suggest that rPilQ(406-770) is a potential vaccine candidate for serogroup B N. meningitidis. Copyright © 2011 Elsevier Ltd. All rights reserved.

  10. Expansion of a urethritis-associated Neisseria meningitidis clade in the United States with concurrent acquisition of N. gonorrhoeae alleles.

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    Retchless, Adam C; Kretz, Cécilia B; Chang, How-Yi; Bazan, Jose A; Abrams, A Jeanine; Norris Turner, Abigail; Jenkins, Laurel T; Trees, David L; Tzeng, Yih-Ling; Stephens, David S; MacNeil, Jessica R; Wang, Xin

    2018-03-02

    Increased reports of Neisseria meningitidis urethritis in multiple U.S. cities during 2015 have been attributed to the emergence of a novel clade of nongroupable N. meningitidis within the ST-11 clonal complex, the "U.S. NmNG urethritis clade". Genetic recombination with N. gonorrhoeae has been proposed to enable efficient sexual transmission by this clade. To understand the evolutionary origin and diversification of the U.S. NmNG urethritis clade, whole-genome phylogenetic analysis was performed to identify its members among the N. meningitidis strain collection from the Centers for Disease Control and Prevention, including 209 urogenital and rectal N. meningitidis isolates submitted by U.S. public health departments in eleven states starting in 2015. The earliest representatives of the U.S. NmNG urethritis clade were identified from cases of invasive disease that occurred in 2013. Among 209 urogenital and rectal isolates submitted from January 2015 to September 2016, the clade accounted for 189/198 male urogenital isolates, 3/4 female urogenital isolates, and 1/7 rectal isolates. In total, members of the clade were isolated in thirteen states between 2013 and 2016, which evolved from a common ancestor that likely existed during 2011. The ancestor contained N. gonorrhoeae-like alleles in three regions of its genome, two of which may facilitate nitrite-dependent anaerobic growth during colonization of urogenital sites. Additional gonococcal-like alleles were acquired as the clade diversified. Notably, one isolate contained a sequence associated with azithromycin resistance in N. gonorrhoeae, but no other gonococcal antimicrobial resistance determinants were detected. Interspecies genetic recombination contributed to the early evolution and subsequent diversification of the U.S. NmNG urethritis clade. Ongoing acquisition of N. gonorrhoeae alleles by the U.S. NmNG urethritis clade may facilitate the expansion of its ecological niche while also increasing the

  11. Cluster of Neisseria gonorrhoeae Isolates With High-level Azithromycin Resistance and Decreased Ceftriaxone Susceptibility, Hawaii, 2016.

    Science.gov (United States)

    Katz, Alan R; Komeya, Alan Y; Kirkcaldy, Robert D; Whelen, A Christian; Soge, Olusegun O; Papp, John R; Kersh, Ellen N; Wasserman, Glenn M; O'Connor, Norman P; O'Brien, Pamela S; Sato, Douglas T; Maningas, Eloisa V; Kunimoto, Gail Y; Tomas, Juval E

    2017-09-15

    The Centers for Disease Control and Prevention (CDC) currently recommends dual therapy with ceftriaxone and azithromycin for gonorrhea to ensure effective treatment and slow emergence of antimicrobial resistance. Since 2013, the prevalence of reduced azithromycin susceptibility increased in the United States; however, these strains were highly susceptible to cephalosporins. We identified a cluster of Neisseria gonorrhoeae isolates with high-level azithromycin resistance, several of which also demonstrated decreased ceftriaxone susceptibility. Eight N. gonorrhoeae isolates collected from 7 patients on Oahu, Hawaii, seen 21 April 2016 through 10 May 2016 underwent routine Etest antimicrobial susceptibility testing by the Hawaii Department of Health. All demonstrated elevated azithromycin minimum inhibitory concentrations (MICs) >256 μg/mL and elevated ceftriaxone MICs (≥0.125 μg/mL). Isolates were sent to the University of Washington and CDC for confirmatory agar dilution testing; sequence data were sent to CDC for analysis. All patients were interviewed and treated, and when possible, partners were interviewed, tested, and treated. All isolates had azithromycin MICs >16 µg/mL and 5 had ceftriaxone MICs = 0.125 µg/mL by agar dilution. All isolates were β-lactamase positive and were resistant to penicillin, tetracycline, and ciprofloxacin. Genomic analysis revealed genetic relatedness. No patients reported recent travel or antibiotic use, and no male patients reported male sex partners. All patients were successfully treated. This cluster of genetically related gonococcal isolates with decreased ceftriaxone susceptibility and high-level azithromycin resistance may bring the threat of treatment failure in the United States with the current recommended dual therapy one step closer. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.

  12. Quality assurance for antimicrobial susceptibility testing of Neisseria gonorrhoeae in Latin American and Caribbean countries, 2013-2015.

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    Sawatzky, Pam; Martin, Irene; Galarza, Patricia; Carvallo, Marıa Elena Trigoso; Araya Rodriguez, Pamela; Cruz, Olga Marina Sanabria; Hernandez, Alina Llop; Martinez, Mario Fabian; Borthagaray, Graciela; Payares, Daisy; Moreno, José E; Chiappe, Marina; Corredor, Aura Helena; Thakur, Sidharath Dev; Dillon, Jo-Anne R

    2018-04-19

    A Neisseria gonorrhoeae antimicrobial susceptibility quality control comparison programme was re-established in Latin America and the Caribbean to ensure antimicrobial susceptibility data produced from the region are comparable nationally and internationally. Three panels, consisting of N. gonorrhoeae isolates comprising reference strains and other characterised isolates were sent to 11 participating laboratories between 2013 and 2015. Antimicrobial susceptibilities for these isolates were determined using agar dilution, Etest or disc diffusion methods. Modal minimum inhibitory concentrations (MICs) for each panel isolate/antibiotic combination were calculated. The guidelines of the Clinical and Laboratory Standards Institute were used for interpretations of antimicrobial susceptibility. The agreement of MICs with the modal MICs was determined for each of the participating laboratories as well as for each of the antibiotics tested. Five of 11 laboratories that participated in at least one panel had an overall average agreement between participants' MIC results and modal MICs of >90%. For other laboratories, agreements ranged from 60.0% to 82.4%. The proportion of agreement between interpretations for all the antibiotics, except penicillin and tetracycline, was >90%. The percentages of agreement between MIC results and their modes for erythromycin, spectinomycin, cefixime and azithromycin were >90%. Tetracycline, ceftriaxone and ciprofloxacin agreement ranged from 84.5% to 89.1%, while penicillin had 78.8% agreement between MICs and modal MICs. The participating laboratories had acceptable results, similar to other international quality assurance programmes. It is important to ensure continuation of the International Gonococcal Antimicrobial Susceptibility Quality Control Comparison Programme to ensure that participants can identify and correct any problems in antimicrobial susceptibility testing for N. gonorrhoeae as they arise and continue to generate reproducible

  13. Neisseria gonorrhoeae co-infection exacerbates vaginal HIV shedding without affecting systemic viral loads in human CD34+ engrafted mice.

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    Stacey X Xu

    Full Text Available HIV synergy with sexually transmitted co-infections is well-documented in the clinic. Co-infection with Neisseria gonorrhoeae in particular, increases genital HIV shedding and mucosal transmission. However, no animal model of co-infection currently exists to directly explore this relationship or to bridge the gap in understanding between clinical and in vitro studies of this interaction. This study aims to test the feasibility of using a humanized mouse model to overcome this barrier. Combining recent in vivo modelling advancements in both HIV and gonococcal research, we developed a co-infection model by engrafting immunodeficient NSG mice with human CD34+ hematopoietic stem cells to generate humanized mice that permit both systemic HIV infection and genital N. gonorrhoeae infection. Systemic plasma and vaginal lavage titres of HIV were measured in order to assess the impact of gonococcal challenge on viral plasma titres and genital shedding. Engrafted mice showed human CD45+ leukocyte repopulation in blood and mucosal tissues. Systemic HIV challenge resulted in 104-105 copies/mL of viral RNA in blood by week 4 post-infection, as well as vaginal shedding of virus. Subsequent gonococcal challenge resulted in unchanged plasma HIV levels but higher viral shedding in the genital tract, which reflects published clinical observations. Thus, human CD34+ stem cell-transplanted NSG mice represent an experimentally tractable animal model in which to study HIV shedding during gonococcal co-infection, allowing dissection of molecular and immunological interactions between these pathogens, and providing a platform to assess future therapeutics aimed at reducing HIV transmission.

  14. Prevalence of Chlamydia trachomatis and Neisseria gonorrhoeae infection in adolescents in Northern Italy: an observational school-based study

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    Alberto Matteelli

    2016-02-01

    Full Text Available Abstract Background We carried out a study to evaluate the prevalence of Chlamydia trachomatis and Neisseria gonorrhoeae genital infections in school-based adolescents in Northern Italy. Methods Systematic screening for C. trachomatis and N. gonorrhoeae genital infection was performed in 13th grade students in the province of Brescia, an industrialized area in Northern Italy. Student filled in a questionnaire on sexual behaviour and provided a urine sample for microbiological testing. Results A total of 2,718 students (mean age: 18.4 years; 59.1 % females provided complete data (62.2 % of those eligible. Overall 2,059 students (75.8 % were sexually active (i.e. had had at least one partner, and the mean age at sexual debut was 16.1 years (SD: 1.4. Only 27.5 % of the sexually active students reported regular condom use during the previous 6 months, with higher frequency in males than in females (33.8 % vs 24.2 %. No case of N. gonorrhoeae infection was detected, while C. trachomatis was found in 36 adolescents, with a prevalence of 1.7 % (95 % CI: 1.2–2.4 among sexually active students, and no statistical difference between females and males (1.9 and 1.4 %, respectively. Inconsistent condom use (odds ratio, OR = 5.5 and having had more than one sexual partner during the previous 6 months (OR = 6.8 were associated with an increased risk of Chlamydia infection at multivariate analysis. Conclusion The prevalence of C. trachomatis infection among sexually active adolescents in Northern Italy was low, despite a high proportion of students who engage in risky sexual behaviour. No cases of N. gonorrhoeae infection were identified.

  15. AtlA functions as a peptidoglycan lytic transglycosylase in the Neisseria gonorrhoeae type IV secretion system.

    Science.gov (United States)

    Kohler, Petra L; Hamilton, Holly L; Cloud-Hansen, Karen; Dillard, Joseph P

    2007-08-01

    Type IV secretion systems require peptidoglycan lytic transglycosylases for efficient secretion, but the function of these enzymes is not clear. The type IV secretion system gene cluster of Neisseria gonorrhoeae encodes two peptidoglycan transglycosylase homologues. One, LtgX, is similar to peptidoglycan transglycosylases from other type IV secretion systems. The other, AtlA, is similar to endolysins from bacteriophages and is not similar to any described type IV secretion component. We characterized the enzymatic function of AtlA in order to examine its role in the type IV secretion system. Purified AtlA was found to degrade macromolecular peptidoglycan and to produce 1,6-anhydro peptidoglycan monomers, characteristic of lytic transglycosylase activity. We found that AtlA can functionally replace the lambda endolysin to lyse Escherichia coli. In contrast, a sensitive measure of lysis demonstrated that AtlA does not lyse gonococci expressing it or gonococci cocultured with an AtlA-expressing strain. The gonococcal type IV secretion system secretes DNA during growth. A deletion of ltgX or a substitution in the putative active site of AtlA severely decreased DNA secretion. These results indicate that AtlA and LtgX are actively involved in type IV secretion and that AtlA is not involved in lysis of gonococci to release DNA. This is the first demonstration that a type IV secretion peptidoglycanase has lytic transglycosylase activity. These data show that AtlA plays a role in type IV secretion of DNA that requires peptidoglycan breakdown without cell lysis.

  16. Mucosal immunization using proteoliposome and cochleate structures from Neisseria meningitidis serogroup B induce mucosal and systemic responses.

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    Campo, Judith Del; Zayas, Caridad; Romeu, Belkis; Acevedo, Reinaldo; González, Elizabeth; Bracho, Gustavo; Cuello, Maribel; Cabrera, Osmir; Balboa, Julio; Lastre, Miriam

    2009-12-01

    Most pathogens either invade the body or establish infection in mucosal tissues and represent an enormous challenge for vaccine development by the absence of good mucosal adjuvants. A proteoliposome-derived adjuvant from Neisseria meningitidis serogroup B (AFPL1, Adjuvant Finlay Proteoliposome 1) and its derived cochleate form (Co, AFCo1) contain multiple pathogen-associated molecular patterns as immunopotentiators, and can also serve as delivery systems to elicit a Th1-type immune response. The present studies demonstrate the ability of AFPL1and AFCo1 to induce mucosal and systemic immune responses by different mucosal immunizations routes and significant adjuvant activity for antibody responses of both structures: a microparticle and a nanoparticle with a heterologous antigen. Therefore, we used female mice immunized by intragastric, intravaginal, intranasal or intramuscular routes with both structures alone or incorporated with ovalbumin (OVA). High levels of specific IgG antibody were detected in all sera and in vaginal washes, but specific IgA antibody in external secretions was only detected in mucosally immunized mice. Furthermore, antigen specific IgG1 and IgG2a isotypes were all induced. AFPL1 and AFCo1 are capable of inducing IFN-gamma responses, and chemokine secretions, like MIP-1alpha and MIP-1beta. However, AFCo1 is a better alternative to induce immune responses at mucosal level. Even when we use a heterologous antigen, the AFCo1 response was better than with AFPL1 in inducing mucosal and systemic immune responses. These results support the use of AFCo1 as a potent Th1 inducing adjuvant particularly suitable for mucosal immunization.

  17. Neisseria gonorrhoeae co-infection exacerbates vaginal HIV shedding without affecting systemic viral loads in human CD34+ engrafted mice.

    Science.gov (United States)

    Xu, Stacey X; Leontyev, Danila; Kaul, Rupert; Gray-Owen, Scott D

    2018-01-01

    HIV synergy with sexually transmitted co-infections is well-documented in the clinic. Co-infection with Neisseria gonorrhoeae in particular, increases genital HIV shedding and mucosal transmission. However, no animal model of co-infection currently exists to directly explore this relationship or to bridge the gap in understanding between clinical and in vitro studies of this interaction. This study aims to test the feasibility of using a humanized mouse model to overcome this barrier. Combining recent in vivo modelling advancements in both HIV and gonococcal research, we developed a co-infection model by engrafting immunodeficient NSG mice with human CD34+ hematopoietic stem cells to generate humanized mice that permit both systemic HIV infection and genital N. gonorrhoeae infection. Systemic plasma and vaginal lavage titres of HIV were measured in order to assess the impact of gonococcal challenge on viral plasma titres and genital shedding. Engrafted mice showed human CD45+ leukocyte repopulation in blood and mucosal tissues. Systemic HIV challenge resulted in 104-105 copies/mL of viral RNA in blood by week 4 post-infection, as well as vaginal shedding of virus. Subsequent gonococcal challenge resulted in unchanged plasma HIV levels but higher viral shedding in the genital tract, which reflects published clinical observations. Thus, human CD34+ stem cell-transplanted NSG mice represent an experimentally tractable animal model in which to study HIV shedding during gonococcal co-infection, allowing dissection of molecular and immunological interactions between these pathogens, and providing a platform to assess future therapeutics aimed at reducing HIV transmission.

  18. Genital infections and reproductive complications associated with Trichomonas vaginalis, Neisseria gonorrhoeae, and Streptococcus agalactiae in women of Qom, central Iran

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    Mahmoud Nateghi Rostam

    2017-07-01

    Full Text Available Background: Trichomonas vaginalis (T.vaginalis and Neisseria gonorrhoeae (N.gonorrhoeae are two most common non-viral sexually transmitted infections in the world. No data are available regarding the epidemiology of genital infections in women of Qom, central Iran. Objective: Epidemiological investigation of sexually transmitted infections in genital specimens of women referred to the referral gynecology hospital in Qom, central Iran. Materials and Methods: Genital swab specimens were collected from women volunteers and used for identification of bacterial and protozoal infections by conventional microbial diagnostics, porA pseudo gene LightCycler® real-time PCR (for N.gonorrhoeae and ITS-PCR (for T.vaginalis. Results: Of 420 volunteers, 277 (65.9% had genital signs/symptoms, including 38.3% malodorous discharge, 37.9% dyspareunia, and 54.8% abdominal pain. Totally, 2 isolates of Streptococcus agalactiae were identified. Five specimens (1.2% in Thayer-Martin culture and 17 (4.1% in real-time PCR were identified as N.gonorrhoeae. Fifty-four specimens (12.9% in wet mount, 64 (15.2% in Dorset’s culture, and 81 (19.3% in ITS-PCR showed positive results for T.vaginalis. Five mixed infections of T.vaginalis+ N.gonorrhoeae were found. The risk of T.vaginalis infection was increased in women with low-birth-weight (p=0.00; OR=43.29, history of abortion (p=0.00; OR=91.84, and premature rupture of membranes (PROM (p=0.00; OR=21.75. The probability of finding nuclear leukocytes (p=0.00; OR=43.34 in vaginal smear was higher in T.vaginalis infection. Conclusion: The significant prevalence of trichomoniasis and gonorrhea emphasizes the need for accurate diagnosis and effective surveillance to prevent serious reproductive complications in women.

  19. Lipooligosaccharide structure is an important determinant in the resistance of Neisseria gonorrhoeae to antimicrobial agents of innate host defense

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    Jacqueline T Balthazar

    2011-02-01

    Full Text Available The strict human pathogen Neisseria gonorrhoeae has caused the sexually transmitted infection termed gonorrhea for thousands of years. Over the millennia, the gonococcus has likely evolved mechanisms to evade host defense systems that operate on the genital mucosal surfaces in both males and females. Past research has shown that the presence or modification of certain cell envelope structures can significantly impact levels of gonococcal susceptibility to host-derived antimicrobial compounds that bathe genital mucosal surfaces and participate in innate host defense against invading pathogens. In order to facilitate the identification of gonococcal genes that are important in determining levels of bacterial susceptibility to mediators of innate host defense, we used the Himar I mariner in vitro mutagenesis system to construct a transposon insertion library in strain F62. As proof of principle that this strategy would be suitable for this purpose, we screened the library for mutants expressing decreased susceptibility to the bacteriolytic action of normal human serum (NHS. We found that a transposon insertion in the lgtD gene, which encodes an N-acetylgalactosamine transferase involved in the extension of the α-chain of lipooligosaccharide (LOS, could confer decreased susceptibility of strain F62 to complement-mediated killing by NHS. By complementation and chemical analyses, we demonstrated both linkage of the transposon insertion to the NHS-resistance phenotype and chemical changes in LOS structure that resulted from loss of LgtD production. Further truncation of the LOS α-chain or loss of phosphoethanolamine (PEA from the lipid A region of LOS also impacted levels of NHS-resistance. PEA decoration of lipid A also increased gonococcal resistance to the model cationic antimicrobial polymyxin B. Taken together, we conclude that the Himar I mariner in vitro mutagenesis procedure can facilitate studies on structures involved in gonococcal

  20. Antigen sequence typing of outer membrane protein (fetA gene of Neisseria meningitidis serogroup A from Delhi & adjoining areas

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    S Dwivedi

    2014-01-01

    Full Text Available Background & objectives: Meningitis caused by Neisseria meningitidis is a fatal disease. Meningococcal meningitis is an endemic disease in Delhi and irregular pattern of outbreaks has been reported in India. All these outbreaks were associated with serogroup A. Detailed molecular characterization of N. meningitidis is required for the management of this fatal disease. In this study, we characterized antigenic diversity of surface exposed outer membrane protein (OMP FetA antigen of N. meningitidis serogroup A isolates obtained from cases of invasive meningococcal meningitis in Delhi, India. Methods: Eight isolates of N. meningitidis were collected from cerebrospinal fluid during October 2008 to May 2011 from occasional cases of meningococcal meningitis. Seven isolates were from outbreaks of meningococcal meningitis in 2005-2006 in Delhi and its adjoining areas. These were subjected to molecular typing of fetA gene, an outer membrane protein gene. Results: All 15 N. meningitides isolates studied were serogroup A. This surface exposed porin is putatively under immune pressure. Hence as a part of molecular characterization, genotyping was carried out to find out the diversity in outer membrane protein (FetA gene among the circulating isolates of N. meningitidis. All 15 isolates proved to be of the same existing allele type of FetA variable region (VR when matched with global database. The allele found was F3-1 for all the isolates. Interpretation & conclusions: There was no diversity reported in the outer membrane protein FetA in the present study and hence this protein appeared to be a stable molecule. More studies on molecular characterization of FetA antigen are required from different serogroups circulating in different parts of the world.

  1. Extracts of Canadian first nations medicinal plants, used as natural products, inhibit neisseria gonorrhoeae isolates with different antibiotic resistance profiles.

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    Cybulska, Paulina; Thakur, Sidharath D; Foster, Brian C; Scott, Ian M; Leduc, Renée I; Arnason, John T; Dillon, Jo-Anne R

    2011-07-01

    Neisseria gonorrhoeae (Ng) has developed resistance to most antimicrobial agents and the antibiotics recommended for therapy are restricted, for the most part, to third generation cephalosporins. In order to investigate new potential sources of antimicrobial agents, the antibacterial properties of 14 Canadian plants used in traditional First Nations' medicine were tested against Ng isolates having differing antimicrobial susceptibility profiles. Ethanolic extracts of 14 Canadian botanicals, analyzed by high-performance liquid chromatography, were tested for their antimicrobial activity (disc diffusion and/or agar dilution assays) against susceptible Ng reference strains and a panel of 28 Ng isolates with various antimicrobial resistance profiles. Extracts of Arctostaphylos uva ursi (kinnikinnick or bearberry), Hydrastis canadensis (goldenseal), Prunus serotina (black cherry), and Rhodiola rosea (roseroot) inhibited the growth of all Ng isolates with minimum inhibitory concentrations of 32 μg/mL, 4 to 32 μg/mL, 16 to >32 μg/mL, and 32 to 64 μg/mL, respectively. Extracts of Acorus americanus (sweet flag), Berberis vulgaris (barberry), Cimicifuga racemosa (black cohosh), Equisetum arvense (field horsetail), Gaultheria procumbens (wintergreen), Ledum groenlandicum (Labrador tea), Ledum palustre (marsh Labrador tea), Oenothera biennis (common evening primrose), Sambucus nigra (elderberry), and Zanthoxylum americanum (prickly ash) had weak or no antimicrobial activity against the Ng isolates with minimum inhibitory concentrations ≥256 μg/mL. The phytochemical berberine from H. canadensis inhibited the growth of all Ng isolates. The phytochemicals, salidroside and rosavin, present in R. rosea, also showed inhibitory activity against Ng strains. Canadian botanicals represent a potential source of novel compounds which inhibit Ng, including isolates resistant to antibiotics.

  2. DprA from Neisseria meningitidis: properties and role in natural competence for transformation.

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    Hovland, Eirik; Beyene, Getachew Tesfaye; Frye, Stephan A; Homberset, Håvard; Balasingham, Seetha V; Gómez-Muñoz, Marta; Derrick, Jeremy P; Tønjum, Tone; Ambur, Ole H

    2017-07-01

    DNA processing chain A (DprA) is a DNA-binding protein that is ubiquitous in bacteria and expressed in some archaea. DprA is active in many bacterial species that are competent for transformation of DNA, but its role in Neisseriameningitidis (Nm) is not well characterized. An Nm mutant lacking DprA was constructed, and the phenotypes of the wild-type and ΔdprA mutant were compared. The salient feature of the phenotype of dprA null cells is the total lack of competence for genetic transformation shown by all of the donor DNA substrates tested in this study. Here, Nm wild-type and dprA null cells appeared to be equally resistant to genotoxic stress. The gene encoding DprANm was cloned and overexpressed, and the biological activities of DprANm were further investigated. DprANm binds ssDNA more strongly than dsDNA, but lacks DNA uptake sequence-specific DNA binding. DprANm dimerization and interaction with the C-terminal part of the single-stranded binding protein SSBNmwere demonstrated. dprA is co-expressed with smg, a downstream gene of unknown function, and the gene encoding topoisomerase 1, topA.

  3. Prevalence of Chlamydia trachomatis, Trichomonas vaginalis and Neisseria gonorrhoeae Based on Data Collected by a Network of Clinical Microbiology Laboratories, in Italy.

    Science.gov (United States)

    Salfa, Maria Cristina; Suligoi, Barbara

    Bacterial and protozoal sexually transmitted infections (STIs), such as Chlamydia trachomatis, Trichomonas vaginalis and Neisseria gonorrhoeae, may cause acute symptoms, chronic infections and severe long-term complications. The complications of these infections in women include pelvic inflammatory disease, chronic pelvic pain, tubal infertility, ectopic pregnancy, and infertility. Moreover, infection during pregnancy is associated with premature rupture of the membranes, low birth weight and miscarriage.In Italy, Chlamydia trachomatis and Trichomonas vaginalis infections are not subject to mandatory reporting; while gonorrhoea is subject to mandatory reporting.To extend surveillance to STIs that are widespread yet often asymptomatic and to improve the knowledge on the epidemiology of these infections in Italy, in 2009 the "Centro Operativo AIDS of the Istituto Superiore di SanitÁ", in collaboration with the Association of Italian Clinical Microbiologists (AMCLI, Associazione Microbiologi Clinici Italiani), launched the sentinel STIs surveillance system based on a network of 13 clinical microbiology laboratories.The main objective of the surveillance was to assess the prevalence and risk factors associated with Chlamydia trachomatis, Trichomonas vaginalis and Neisseria gonorrhoea infections among individuals attending microbiology laboratories in Italy.

  4. Vigilancia de la resistencia de Neisseria gonorrhoeae en un hospital de la provincia de Santa Fe, Argentina: 1997-2004 Resistance surveillance of Neisseria gonorrhoeae in a hospital in Santa Fe province, Argentina: 1997-2004

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    E. De Los A. Méndez

    2008-09-01

    Full Text Available Se determinaron los fenotipos de resistencia caracterizados por la concentración inhibitoria mínima, la difusión con discos y la producción de β-lactamasa de 434 aislamientos de Neisseria gonorrhoeae obtenidos de pacientes atendidos en el Servicio de Enfermedades de Transmisión Sexual del Hospital Dr. José María Cullen, Santa Fe, Argentina. Se realizaron pruebas de sensibilidad a los siguientes antimicrobianos: penicilina, tetraciclina, ciprofloxacina, espectinomicina, azitromicina y ceftriaxona. A tres aislamientos resistentes a ciprofloxacina se les realizó electroforesis de campo pulsado. Se destacaron tres situaciones epidemiológicas de interés: en el año 1997, alta incidencia de aislamientos con resistencia plasmídica a tetraciclina (33,3%; en el período 2002-2004, un aumento significativo de la resistencia plasmídica a penicilina (9,7% a 34,8%; y en el año 2000, la emergencia de dos de los tres primeros aislamientos con resistencia a quinolonas del país. El primer aislamiento resistente a azitromicina en nuestro hospital emerge en el 2004. Este trabajo jerarquiza el rol del Laboratorio de Microbiología Clínica en la orientación del tratamiento empírico de la gonorrea.Resistance phenotypes characterized by minimum inhibitory concentration, disk diffusion and β-lactamase production were determined in 434 isolates from patients attending the Sexually Transmitted Disease Service at Dr. José María Cullen Hospital in Santa Fe, Argentina. Susceptibility tests to penicillin, tetracycline, ciprofloxacin, espectinomycin, azithromycin and ceftriaxone were performed. Pulsed-field gel electrophoresis was conducted made to on three ciprofloxacin-resistant isolates. Epidemiologically speaking, three interesting events should be highlighted: during 1997, plasmid-mediated high level tetracycline-resistant strains were observed (33.3%; from 2002 to 2004 a significant increase of plasmid-mediated penicillin-resistant strains was

  5. Amplified Fragment Length Polymorphism Fingerprinting for Identification of a Core Group of Neisseria gonorrhoeae Transmitters in the Population Attending a Clinic for Treatment of Sexually Transmitted Diseases in Amsterdam, The Netherlands

    OpenAIRE

    Spaargaren, Joke; Stoof, Jeroen; Fennema, Han; Coutinho, Roel; Savelkoul, Paul

    2001-01-01

    Amplified fragment length polymorphism analysis seems well suited for studying the epidemiology of isolates of Neisseria gonorrhoeae obtained from patients attending the Sexually Transmitted Disease Outpatient Clinic in Amsterdam, The Netherlands. It shows potential to identify the core group of transmitters.

  6. Working mechanism of immunoglobulin A1 (IgA1) protease: cleavage of IgA1 antibody to Neisseria meningitidis PorA requires de novo synthesis of IgA1 Protease

    NARCIS (Netherlands)

    Vidarsson, Gestur; Overbeeke, Natasja; Stemerding, Annette M.; van den Dobbelsteen, Germie; van Ulsen, Peter; van der Ley, Peter; Kilian, Mogens; van de Winkel, Jan G. J.

    2005-01-01

    Neisseria meningitidis secretes a protease that specifically cleaves the hinge region of immunoglobulin A1 (IgA1), releasing the effector (Fc) domain of IgA1 from the antigen binding (Fab) determinants. Theoretically, the remaining Fab fragments can block pathogen receptors or toxins and still

  7. Working mechanism of immunoglobulin A1 (IgA1) protease: cleavage of IgA1 antibody to Neisseria meningitidis PorA requires de novo synthesis of IgA1 Protease

    DEFF Research Database (Denmark)

    Vidarsson, G; Overbeeke, N; Stemerding, AM

    2005-01-01

    Neisseria meningitidis secretes a protease that specifically cleaves the hinge region of immunoglobulin A1 (IgA1), releasing the effector (Fc) domain of IgA1 from the antigen binding (Fab) determinants. Theoretically, the remaining Fab fragments can block pathogen receptors or toxins and still...

  8. Neisseria meningitidis RTX protein FrpC induced high levels of serum antibodies during invasive disease: polymorphism of frpC alleles and purification of recombinant FrpC

    Czech Academy of Sciences Publication Activity Database

    Osička, Radim; Kalmusová, J.; Křížová, P.; Šebo, Peter

    2001-01-01

    Roč. 69, č. 9 (2001), s. 5509-5519 ISSN 0019-9567 R&D Projects: GA ČR GV310/96/K102; GA MŠk ME 167 Institutional research plan: CEZ:AV0Z5020903 Keywords : Neisseria meningitidis * meningococcal infections Subject RIV: EE - Microbiology, Virology Impact factor: 4.212, year: 2001

  9. Nitrogen consumption during batch cultivation of Neisseria meningitidis (serogroup C in Frantz medium Consumo de nitrogênio durante cultivo descontínuo de Neisseria meningitidis (sorogrupo C em meio de Frantz

    Directory of Open Access Journals (Sweden)

    Júlia Baruque-Ramos

    2001-12-01

    Full Text Available Capsular polysaccharide, extracted from microorganism cultivations, is the principal antigen for elaboration of vaccine against the disease caused by Neisseria meningitidis serogroup C. The final protein content allowed in this vaccine is 1%. In order to find a relationship between nitrogen consumption and cell growth, including polysaccharide production, and cell nitrogen content, cultivations were carried out in an 80 liters bioreactor (total capacity, under the following conditions: Frantz medium; temperature of 35ºC; air flow of 5 L/min (0.125 vvm; agitation frequency of 120 rpm and vessel pressure of 6 psi (kLa = 0.07 min-1. Concentrations of biomass, total polysaccharide, cellular nitrogen, residual organic and inorganic nitrogen in the medium were measured during cultivation. From five cultivations carried out under the same conditions, a mean cell nitrogen percentage of 12.6% (w/w in respect to the dry biomass was found. The inorganic nitrogen in the medium did not change significantly along the cultivation time, whereas the organic nitrogen consumption was linearly related to cell growth, with constant yield factors (average of 8.44. Polysaccharide production kinetics followed the cell growth kinetics until the beginning of the stationary growth phase. A supplemental polysaccharide production was observed until the end of cultivation, but without cell nitrogen absorption. Thus, the results indicate that polysaccharide is produced in two phases, being the first one biomass formation followed by non-associated to growth.Polissacarídeo capsular, extraído de cultivos microbianos, é o principal antígeno para o preparo da vacina contra a doença causada por Neisseria meningitidis sorogrupo C. O conteúdo final de proteína permitido nessa vacina é de 1%. De modo a encontrar uma relação entre o consumo de nitrogênio, o crescimento microbiano (incluindo a produção de polissacarídeo e o conteúdo de nitrogênio celular, cultivos

  10. Estimating the fitness cost and benefit of cefixime resistance in Neisseria gonorrhoeae to inform prescription policy: A modelling study.

    Directory of Open Access Journals (Sweden)

    Lilith K Whittles

    2017-10-01

    Full Text Available Gonorrhoea is one of the most common bacterial sexually transmitted infections in England. Over 41,000 cases were recorded in 2015, more than half of which occurred in men who have sex with men (MSM. As the bacterium has developed resistance to each first-line antibiotic in turn, we need an improved understanding of fitness benefits and costs of antibiotic resistance to inform control policy and planning. Cefixime was recommended as a single-dose treatment for gonorrhoea from 2005 to 2010, during which time resistance increased, and subsequently declined.We developed a stochastic compartmental model representing the natural history and transmission of cefixime-sensitive and cefixime-resistant strains of Neisseria gonorrhoeae in MSM in England, which was applied to data on diagnoses and prescriptions between 2008 and 2015. We estimated that asymptomatic carriers play a crucial role in overall transmission dynamics, with 37% (95% credible interval CrI 24%-52% of infections remaining asymptomatic and untreated, accounting for 89% (95% CrI 82%-93% of onward transmission. The fitness cost of cefixime resistance in the absence of cefixime usage was estimated to be such that the number of secondary infections caused by resistant strains is only about half as much as for the susceptible strains, which is insufficient to maintain persistence. However, we estimated that treatment of cefixime-resistant strains with cefixime was unsuccessful in 83% (95% CrI 53%-99% of cases, representing a fitness benefit of resistance. This benefit was large enough to counterbalance the fitness cost when 31% (95% CrI 26%-36% of cases were treated with cefixime, and when more than 55% (95% CrI 44%-66% of cases were treated with cefixime, the resistant strain had a net fitness advantage over the susceptible strain. Limitations include sparse data leading to large intervals on key model parameters and necessary assumptions in the modelling of a complex epidemiological process

  11. Characterization of the dsDNA prophage sequences in the genome of Neisseria gonorrhoeae and visualization of productive bacteriophage

    Directory of Open Access Journals (Sweden)

    Maugel Timothy K

    2007-07-01

    Full Text Available Abstract Background Bioinformatic analysis of the genome sequence of Neisseria gonorrhoeae revealed the presence of nine probable prophage islands. The distribution, conservation and function of many of these sequences, and their ability to produce bacteriophage particles are unknown. Results Our analysis of the genomic sequence of FA1090 identified five genomic regions (NgoΦ1 – 5 that are related to dsDNA lysogenic phage. The genetic content of the dsDNA prophage sequences were examined in detail and found to contain blocks of genes encoding for proteins homologous to proteins responsible for phage DNA replication, structural proteins and proteins responsible for phage assembly. The DNA sequences from NgoΦ1, NgoΦ2 and NgoΦ3 contain some significant regions of identity. A unique region of NgoΦ2 showed very high similarity with the Pseudomonas aeruginosa generalized transducing phage F116. Comparative analysis at the nucleotide and protein levels suggests that the sequences of NgoΦ1 and NgoΦ2 encode functionally active phages, while NgoΦ3, NgoΦ4 and NgoΦ5 encode incomplete genomes. Expression of the NgoΦ1 and NgoΦ2 repressors in Escherichia coli inhibit the growth of E. coli and the propagation of phage λ. The NgoΦ2 repressor was able to inhibit transcription of N. gonorrhoeae genes and Haemophilus influenzae HP1 phage promoters. The holin gene of NgoΦ1 (identical to that encoded by NgoΦ2, when expressed in E. coli, could serve as substitute for the phage λ s gene. We were able to detect the presence of the DNA derived from NgoΦ1 in the cultures of N. gonorrhoeae. Electron microscopy analysis of culture supernatants revealed the presence of multiple forms of bacteriophage particles. Conclusion These data suggest that the genes similar to dsDNA lysogenic phage present in the gonococcus are generally conserved in this pathogen and that they are able to regulate the expression of other neisserial genes. Since phage particles were

  12. Overall Low Extended-Spectrum Cephalosporin Resistance but high Azithromycin Resistance in Neisseria gonorrhoeae in 24 European Countries, 2015.

    Science.gov (United States)

    Cole, Michelle J; Spiteri, Gianfranco; Jacobsson, Susanne; Woodford, Neil; Tripodo, Francesco; Amato-Gauci, Andrew J; Unemo, Magnus

    2017-09-11

    Surveillance of Neisseria gonorrhoeae antimicrobial susceptibility in Europe is performed through the European Gonococcal Antimicrobial Surveillance Programme (Euro-GASP), which additionally provides data to inform the European gonorrhoea treatment guideline; currently recommending ceftriaxone 500 mg plus azithromycin 2 g as first-line therapy. We present antimicrobial susceptibility data from 24 European countries in 2015, linked to epidemiological data of patients, and compare the results to Euro-GASP data from previous years. Antimicrobial susceptibility testing by MIC gradient strips or agar dilution methodology was performed on 2134 N. gonorrhoeae isolates and interpreted using EUCAST breakpoints. Patient variables associated with resistance were established using logistic regression to estimate odds ratios (ORs). In 2015, 1.7% of isolates were cefixime resistant compared to 2.0% in 2014. Ceftriaxone resistance was detected in only one (0.05%) isolate in 2015, compared with five (0.2%) in 2014. Azithromycin resistance was detected in 7.1% of isolates in 2015 (7.9% in 2014), and five (0.2%) isolates displayed high-level azithromycin resistance (MIC ≥ 256 mg/L) compared with one (0.05%) in 2014. Ciprofloxacin resistance remained high (49.4%, vs. 50.7% in 2014). Cefixime resistance significantly increased among heterosexual males (4.1% vs. 1.7% in 2014), which was mainly attributable to data from two countries with high cefixime resistance (~11%), however rates among men-who-have-sex-with-men (MSM) and females continued to decline to 0.5% and 1%, respectively. Azithromycin resistance in MSM and heterosexual males was higher (both 8.1%) than in females (4.9% vs. 2.2% in 2014). The association between azithromycin resistance and previous gonorrhoea infection, observed in 2014, continued in 2015 (OR 2.1, CI 1.2-3.5, p resistance and low overall resistance to ceftriaxone and cefixime. The low cephalosporin resistance may be attributable to the effectiveness

  13. Utilizing CMP-Sialic Acid Analogs to Unravel Neisseria gonorrhoeae Lipooligosaccharide-Mediated Complement Resistance and Design Novel Therapeutics.

    Directory of Open Access Journals (Sweden)

    Sunita Gulati

    2015-12-01

    Full Text Available Neisseria gonorrhoeae deploys a novel immune evasion strategy wherein the lacto-N-neotetraose (LNnT structure of lipooligosaccharide (LOS is capped by the bacterial sialyltransferase, using host cytidine-5'-monophosphate (CMP-activated forms of the nine-carbon nonulosonate (NulO sugar N-acetyl-neuraminic acid (Neu5Ac, a sialic acid (Sia abundant in humans. This allows evasion of complement-mediated killing by recruiting factor H (FH, an inhibitor of the alternative complement pathway, and by limiting classical pathway activation ("serum-resistance". We utilized CMP salts of six additional natural or synthetic NulOs, Neu5Gc, Neu5Gc8Me, Neu5Ac9Ac, Neu5Ac9Az, legionaminic acid (Leg5Ac7Ac and pseudaminic acid (Pse5Ac7Ac, to define structural requirements of Sia-mediated serum-resistance. While all NulOs except Pse5Ac7Ac were incorporated into the LNnT-LOS, only Neu5Gc incorporation yielded high-level serum-resistance and FH binding that was comparable to Neu5Ac, whereas Neu5Ac9Az and Leg5Ac7Ac incorporation left bacteria fully serum-sensitive and did not enhance FH binding. Neu5Ac9Ac and Neu5Gc8Me rendered bacteria resistant only to low serum concentrations. While serum-resistance mediated by Neu5Ac was associated with classical pathway inhibition (decreased IgG binding and C4 deposition, Leg5Ac7Ac and Neu5Ac9Az incorporation did not inhibit the classical pathway. Remarkably, CMP-Neu5Ac9Az and CMP-Leg5Ac7Ac each prevented serum-resistance despite a 100-fold molar excess of CMP-Neu5Ac in growth media. The concomitant presence of Leg5Ac7Ac and Neu5Ac on LOS resulted in uninhibited classical pathway activation. Surprisingly, despite near-maximal FH binding in this instance, the alternative pathway was not regulated and factor Bb remained associated with bacteria. Intravaginal administration of CMP-Leg5Ac7Ac to BALB/c mice infected with gonorrhea (including a multidrug-resistant isolate reduced clearance times and infection burden. Bacteria recovered

  14. Prevalence and treatment outcomes of routine Chlamydia trachomatis, Neisseria gonorrhoeae and Trichomonas vaginalis testing during antenatal care, Gaborone, Botswana.

    Science.gov (United States)

    Wynn, Adriane; Ramogola-Masire, Doreen; Gaolebale, Ponatshego; Moshashane, Neo; Sickboy, Ontiretse; Duque, Sofia; Williams, Elizabeth; Doherty, Klara; Klausner, Jeffrey D; Morroni, Chelsea

    2017-11-02

    Chlamydia trachomatis (CT) , Neisseria gonorrhoeae (NG) and Trichomonas vaginalis (TV) are curable, mostly asymptomatic, STIs that cause adverse maternal and perinatal outcomes. Most countries do not test for those infections during antenatal care. We implemented a CT, NG and TV testing and treatment programme in an antenatal clinic in Gaborone, Botswana. We conducted a prospective study in the antenatal clinic at Princess Marina Hospital in Gaborone, Botswana. We offered pregnant women who were 18 years or older and less than 35 weeks of gestation, CT, NG and TV testing using self-collected vaginal swabs. Testing was conducted using a GeneXpert® CT/NG and TV system. Those who tested positive were given directly observed antibiotic therapy and asked to return for a test of cure. We determined the prevalence of infections, uptake of treatment and proportion cured. The relationships between positive STI test and participant characteristics were assessed. We enrolled 400 pregnant women. Fifty-four (13.5%) tested positive for CT, NG and/or TV: 31 (8%) for CT, 5 (1.3%) for NG and 21 (5%) for TV. Among those who tested positive, 74% (40) received same-day, in person results and treatment. Among those who received delayed results (6), 67% (4) were treated. Statistical comparisons showed that being unmarried and HIV infected were positively association CT, NG and/or TV infection. Self-reported STI symptoms were not associated with CT, NG and/or TV infection. The prevalence of CT, NG and/or TV was high, particularly among women with HIV infection. Among women with CT, NG and/or TV infection, those who received same-day results were more likely to be treated than those who received delayed results. More research is needed on the costs and benefits of integrating highly sensitive and specific STI testing into antenatal care in Southern Africa. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No

  15. Type III methyltransferase M.NgoAX from Neisseria gonorrhoeae FA1090 regulates biofilm formation and human cell invasion

    Directory of Open Access Journals (Sweden)

    Agnieszka eKwiatek

    2015-12-01

    Full Text Available Neisseria gonorrhoeae is the etiological factor of the sexually transmitted gonorrhea disease that may lead, under specific conditions, to systemic infections. The gonococcal genome encodes many Restriction Modification (RM systems, which main biological role is to defend the pathogen from potentially harmful foreign DNA. However, RM systems seem also to be involved in several other functions. In this study, we examined the effect of inactivation the N. gonorrhoeae FA1090 ngo0545 gene encoding M.NgoAX methyltransferase on the global gene expression, biofilm formation, interactions with human epithelial host cells and overall bacterial growth. Expression microarrays showed at least a two-fold deregulation of a total of 121 genes in the NgoAX knock-out mutant compared to the wt strain under standard grow conditions. As determined by the assay with crystal violet, the NgoAX knock-out strain formed a slightly larger biofilm biomass per cell than the wt strain (OD570/600 = 13.8  2.24 and 9.35  2.06, respectively. SCLM observations showed that the biofilm formed by the gonococcal ngo0545 gene mutant is more relaxed and dispersed than the one formed by the wt strain. Thickness of the biofilm formed by both strains was 48.3 (14.9 µm for the mutant and 28.6 (4.0 µm for the wt. This more relaxed feature of the biofilm in respect to adhesion and bacterial interactions seems advantageous for pathogenesis of the NgoAX-deficient gonococci at the stage of human epithelial cell invasion. Indeed, the overall adhesion of mutant bacterial cells to human cells was lower than adhesion of the wt gonococci (adhesion index = 0.672 ( 0.2 and 2.15 ( 1.53, respectively; yet, a higher number of mutant than wt bacteria were found inside the Hec-1-B epithelial cells (invasion index = 3.38 ( 0.93  105 for mutant and 4.67 ( 3.09  104 for the wt strain. These results indicate that NgoAX-deficient cells have lower ability to attach to human cells

  16. Performance of the Abbott RealTime CT/NG for Detection of Chlamydia trachomatis and Neisseria gonorrhoeae▿

    Science.gov (United States)

    Gaydos, C. A.; Cartwright, C. P.; Colaninno, P.; Welsch, J.; Holden, J.; Ho, S. Y.; Webb, E. M.; Anderson, C.; Bertuzis, R.; Zhang, L.; Miller, T.; Leckie, G.; Abravaya, K.; Robinson, J.

    2010-01-01

    A multicenter clinical study was conducted to evaluate the performance characteristics of the Abbott RealTime CT/NG assay, a multiplex real-time PCR assay, for simultaneous detection of Chlamydia trachomatis and Neisseria gonorrhoeae. The specimens were collected from a total of 3,832 male and female subjects at 16 geographically diverse sites. Specimens included male and female urine samples, male urethral swabs, female endocervical swabs, and self-collected and clinician-collected vaginal swabs. Specimens were tested with the automated Abbott RealTime CT/NG assay, Aptima Combo 2 assay (Gen-Probe), ProbeTec ET CT/GC assay (Becton Dickinson), and culture for N. gonorrhoeae. The Aptima Combo 2 assay, the ProbeTec assay, and the N. gonorrhoeae culture were used as the reference assays. For each subject, a patient infected status (PIS) was determined based on the combined results from the reference assays. The overall prevalence in female subjects was 8.9% for C. trachomatis and 3.8% for N. gonorrhoeae. The overall male prevalence was 18.2% for C. trachomatis and 16.7% for N. gonorrhoeae. The overall sensitivity and specificity of the Abbott RealTime CT/NG assay were 92.4% and 99.2% for C. trachomatis and 96.9% and 99.7% for N. gonorrhoeae, respectively. In comparison, the sensitivity and specificity, respectively, for the Aptima Combo 2 assay were 94.5% and 99.0% for C. trachomatis and 96.1% and 99.5% for N. gonorrhoeae, and those for the ProbeTec ET assay were 90.3% and 99.5% for C. trachomatis and 92.0% and 97.3% for N. gonorrhoeae in this study. The Abbott RealTime CT/NG assay offers C. trachomatis and N. gonorrhoeae dual detection with high sensitivity and specificity. The automated assay provides a useful alternative nucleic acid amplification assay for clinical laboratories and clinicians. PMID:20668135

  17. Performance of the Abbott RealTime CT/NG for detection of Chlamydia trachomatis and Neisseria gonorrhoeae.

    Science.gov (United States)

    Gaydos, C A; Cartwright, C P; Colaninno, P; Welsch, J; Holden, J; Ho, S Y; Webb, E M; Anderson, C; Bertuzis, R; Zhang, L; Miller, T; Leckie, G; Abravaya, K; Robinson, J

    2010-09-01

    A multicenter clinical study was conducted to evaluate the performance characteristics of the Abbott RealTime CT/NG assay, a multiplex real-time PCR assay, for simultaneous detection of Chlamydia trachomatis and Neisseria gonorrhoeae. The specimens were collected from a total of 3,832 male and female subjects at 16 geographically diverse sites. Specimens included male and female urine samples, male urethral swabs, female endocervical swabs, and self-collected and clinician-collected vaginal swabs. Specimens were tested with the automated Abbott RealTime CT/NG assay, Aptima Combo 2 assay (Gen-Probe), ProbeTec ET CT/GC assay (Becton Dickinson), and culture for N. gonorrhoeae. The Aptima Combo 2 assay, the ProbeTec assay, and the N. gonorrhoeae culture were used as the reference assays. For each subject, a patient infected status (PIS) was determined based on the combined results from the reference assays. The overall prevalence in female subjects was 8.9% for C. trachomatis and 3.8% for N. gonorrhoeae. The overall male prevalence was 18.2% for C. trachomatis and 16.7% for N. gonorrhoeae. The overall sensitivity and specificity of the Abbott RealTime CT/NG assay were 92.4% and 99.2% for C. trachomatis and 96.9% and 99.7% for N. gonorrhoeae, respectively. In comparison, the sensitivity and specificity, respectively, for the Aptima Combo 2 assay were 94.5% and 99.0% for C. trachomatis and 96.1% and 99.5% for N. gonorrhoeae, and those for the ProbeTec ET assay were 90.3% and 99.5% for C. trachomatis and 92.0% and 97.3% for N. gonorrhoeae in this study. The Abbott RealTime CT/NG assay offers C. trachomatis and N. gonorrhoeae dual detection with high sensitivity and specificity. The automated assay provides a useful alternative nucleic acid amplification assay for clinical laboratories and clinicians.

  18. Transcriptome analysis of Neisseria meningitidis in human whole blood and mutagenesis studies identify virulence factors involved in blood survival.

    Directory of Open Access Journals (Sweden)

    Hebert Echenique-Rivera

    2011-05-01

    Full Text Available During infection Neisseria meningitidis (Nm encounters multiple environments within the host, which makes rapid adaptation a crucial factor for meningococcal survival. Despite the importance of invasion into the bloodstream in the meningococcal disease process, little is known about how Nm adapts to permit survival and growth in blood. To address this, we performed a time-course transcriptome analysis using an ex vivo model of human whole blood infection. We observed that Nm alters the expression of ≈30% of ORFs of the genome and major dynamic changes were observed in the expression of transcriptional regulators, transport and binding proteins, energy metabolism, and surface-exposed virulence factors. In particular, we found that the gene encoding the regulator Fur, as well as all genes encoding iron uptake systems, were significantly up-regulated. Analysis of regulated genes encoding for surface-exposed proteins involved in Nm pathogenesis allowed us to better understand mechanisms used to circumvent host defenses. During blood infection, Nm activates genes encoding for the factor H binding proteins, fHbp and NspA, genes encoding for detoxifying enzymes such as SodC, Kat and AniA, as well as several less characterized surface-exposed proteins that might have a role in blood survival. Through mutagenesis studies of a subset of up-regulated genes we were able to identify new proteins important for survival in human blood and also to identify additional roles of previously known virulence factors in aiding survival in blood. Nm mutant strains lacking the genes encoding the hypothetical protein NMB1483 and the surface-exposed proteins NalP, Mip and NspA, the Fur regulator, the transferrin binding protein TbpB, and the L-lactate permease LctP were sensitive to killing by human blood. This increased knowledge of how Nm responds to adaptation in blood could also be helpful to develop diagnostic and therapeutic strategies to control the devastating

  19. Molecular characterization of two high-level ceftriaxone-resistant Neisseria gonorrhoeae isolates detected in Catalonia, Spain.

    Science.gov (United States)

    Cámara, Jordi; Serra, Judit; Ayats, Josefina; Bastida, Teresa; Carnicer-Pont, Dolors; Andreu, Antònia; Ardanuy, Carmen

    2012-08-01

    The aim of this study was to characterize the first two extended-spectrum cephalosporin-resistant and multidrug-resistant (MDR) Neisseria gonorrhoeae isolates collected from two sexually related patients (men who have sex with men) in Spain. Antimicrobial susceptibility was studied by Etest. Genes involved in quinolone, ceftriaxone and multidrug resistance were amplified by PCR and sequenced in both directions. The isolates were typed by N. gonorrhoeae multi-antigen sequence typing (NG-MAST). The two isolates had the same MDR profile, showing resistance to penicillin (MIC 0.094 mg/L; β-lactamase negative), ceftriaxone (MIC 1.5 mg/L), cefixime (MIC 1.5 mg/L), cefotaxime (MIC 1 mg/L), ciprofloxacin (MIC >32 mg/L) and tetracycline (MIC 1.5 mg/L). NG-MAST showed that both isolates belonged to sequence type (ST) 1407 (porB-908 and tbpB-110). Ciprofloxacin resistance was due to amino acid substitutions in GyrA (S91F and D95G) and ParC (S87R). An A deletion in the promoter of the MtrCDE efflux pump (mtrR) was detected. No changes were detected in the pilQ gene. The outer membrane protein PorB showed two substitutions at G120K and A121N. An L421P substitution was observed in the PBP1A (ponA) sequence. The sequence of PBP2 (penA) showed a mosaic structure related to genotype XXXIV with a single additional amino acid substitution (A501P). This genotype was identical to a recently described French isolate (F89). This is the first reported case of high-level extended-spectrum cephalosporin-resistant N. gonorrhoeae transmission. The molecular typing and MDR genotype suggest possible European spread of this strain, highlighting the need for surveillance and the importance of testing the susceptibility of N. gonorrhoeae to extended-spectrum cephalosporins.

  20. Susceptibility to invasive meningococcal disease: polymorphism of complement system genes and Neisseria meningitidis factor H binding protein.

    Directory of Open Access Journals (Sweden)

    Declan T Bradley

    Full Text Available Neisseria meningitidis can cause severe infection in humans. Polymorphism of Complement Factor H (CFH is associated with altered risk of invasive meningococcal disease (IMD. We aimed to find whether polymorphism of other complement genes altered risk and whether variation of N. meningitidis factor H binding protein (fHBP affected the risk association.We undertook a case-control study with 309 European cases and 5,200 1958 Birth Cohort and National Blood Service cohort controls. We used additive model logistic regression, accepting P<0.05 as significant after correction for multiple testing. The effects of fHBP subfamily on the age at infection and severity of disease was tested using the independent samples median test and Student's T test. The effect of CFH polymorphism on the N. meningitidis fHBP subfamily was investigated by logistic regression and Chi squared test.Rs12085435 A in C8B was associated with odds ratio (OR of IMD (0.35 [95% CI 0.19-0.67]; P = 0.03 after correction. A CFH haplotype tagged by rs3753396 G was associated with IMD (OR 0.56 [95% CI 0.42-0.76], P = 1.6x10⁻⁴. There was no bacterial load (CtrA cycle threshold difference associated with carriage of this haplotype. Host CFH haplotype and meningococcal fHBP subfamily were not associated. Individuals infected with meningococci expressing subfamily A fHBP were younger than those with subfamily B fHBP meningococci (median 1 vs 2 years; P = 0.025.The protective CFH haplotype alters odds of IMD without affecting bacterial load for affected heterozygotes. CFH haplotype did not affect the likelihood of infecting meningococci having either fHBP subfamily. The association between C8B rs12085435 and IMD requires independent replication. The CFH association is of interest because it is independent of known functional polymorphisms in CFH. As fHBP-containing vaccines are now in use, relationships between CFH polymorphism and vaccine effectiveness and side-effects may become

  1. Prevalent bacterial species and novel phylotypes in advanced noma lesions.

    Science.gov (United States)

    Paster, B J; Falkler Jr, W A; Enwonwu, C O; Idigbe, E O; Savage, K O; Levanos, V A; Tamer, M A; Ericson, R L; Lau, C N; Dewhirst, F E

    2002-06-01

    The purpose of this study was to determine the bacterial diversity in advanced noma lesions using culture-independent molecular methods. 16S ribosomal DNA bacterial genes from DNA isolated from advanced noma lesions of four Nigerian children were PCR amplified with universally conserved primers and spirochetal selective primers and cloned into Escherichia coli. Partial 16S rRNA sequences of approximately 500 bases from 212 cloned inserts were used initially to determine species identity or closest relatives by comparison with sequences of known species or phylotypes. Nearly complete sequences of approximately 1,500 bases were obtained for most of the potentially novel species. A total of 67 bacterial species or phylotypes were detected, 25 of which have not yet been grown in vitro. Nineteen of the species or phylotypes, including Propionibacterium acnes, Staphylococcus spp., and the opportunistic pathogens Stenotrophomonas maltophilia and Ochrobactrum anthropi were detected in more than one subject. Other known species that were detected included Achromobacter spp., Afipia spp., Brevundimonas diminuta, Capnocytophaga spp., Cardiobacterium sp., Eikenella corrodens, Fusobacterium spp., Gemella haemoylsans, and Neisseria spp. Phylotypes that were unique to noma infections included those in the genera Eubacterium, Flavobacterium, Kocuria, Microbacterium, and Porphyromonas and the related Streptococcus salivarius and genera Sphingomonas and TREPONEMA: Since advanced noma lesions are infections open to the environment, it was not surprising to detect species not commonly associated with the oral cavity, e.g., from soil. Several species previously implicated as putative pathogens of noma, such as spirochetes and Fusobacterium spp., were detected in at least one subject. However, due to the limited number of available noma subjects, it was not possible at this time to associate specific species with the disease.

  2. Replacement of glycoprotein B gene in the Herpes simplex virus type 1 strain ANGpath DNA that originating from non-pathogenic strain KOS reduces the pathogenicity of recombinant virus

    International Nuclear Information System (INIS)

    Kostal, M.; Bacik, I.; Rajcani, J.; Kaerner, H.C.

    1994-01-01

    Herpes simplex virus type-1 (HSV-1) strain ANGpath and its recombinants, in which the 8.1 kbp BamHI G restriction fragment (0.345-0.399) containing the glycoprotein B (gB path ) gene (UL27) or its sub-fragments-coding either for cytoplasmic or surface domain of gB-had been replaced with the corresponding fragments from non-pathogenic KOS virus DNA (gB KOS ), were tested for their pathogenicity for DBA/2 mice and rabbits. The recombinant ANGpath/B6 KOS prepared by transferring the 2.7 kbp SstI-SstI sub-fragment (0.351-0.368) of the BamHI G KOS fragment still had the original sequence of ANGpath DNA coding for the syn 3 marker in the cytoplasmic domain of gB and was pathogenic for mice as well as for rabbits. Virological and immuno-histological studies in DBA/2 mice infected with the latter pathogenic recombinant and with ANGpath showed the presence of infectious virus and viral antigen at inoculation site (epidermis, subcutaneous connective tissue and striated muscle in the area of right lip), in homo-lateral trigeminal nerve and ganglion, brain stem, midbrain, thalamic and hypothalamic nuclei. In contrast, non-pathogenic recombinants ANGpath/syn + B6 KOS (prepared by transferring the whole BamHI G KOS fragment) and ANGpath/syn +KOS (prepared by transferring the 0.8 kbp BamHI-SstI sub-fragment of the BamHI G KOS fragment) showed limited hematogenous and neural spread, but no evidence of replication in CNS; thus, their behaviour resembled that of the wild type strain KOS. The recombinant ANGpath/syn +KOS , which was not pathogenic for mice, still remained pathogenic for rabbits, a phenomenon indicating the presence of an additional locus in the gB molecule participating on virulence. Sequencing the 1478 bp SstI-SstI sub-fragment of the BamHI G path fragment (nt 53,348 - 54,826 of UL segment) showed the presence of at least 3 mutations as compared to the KOS sequence, from which the change of cytosine at nt 54,2251 altered the codon for arginine to that histidine

  3. Vigilancia de Neisseria meningitidis en Argentina, 1993-2005: distribución de serogrupos, serotipos y serosubtipos causantes de enfermedad invasiva Surveillance of Neisseria meningitidis in Argentina, 1993-2005: Distribution of serogroups, serotypes and serosubtypes isolated from invasive disease

    OpenAIRE

    L. Chiavetta; E. Chávez; A. Ruzic; M. Mollerach; M. Regueira

    2007-01-01

    Neisseria meningitidis es agente causal de enfermedades severas como meningitis, bacteriemia y síndrome de shock séptico. Se presenta la distribución en serogrupos, serotipos y serosubtipos de 2244 aislamientos de N. meningitidis obtenidos de cuadros de meningitis y/o meningococcemia durante el período 1993-2005 y analizados en el Laboratorio Nacional de Referencia del INEI-ANLIS "Dr. Carlos G. Malbrán". Estos aislamientos eran provenientes de 33 hospitales de todo el país, conformados en una...

  4. Native Mitral Valve Endocarditis Caused by Neisseria elongata subsp. nitroreducens in a Patient with Marfan Syndrome: First Case in Italy and Review of the Literature

    Directory of Open Access Journals (Sweden)

    Parrinello Rossella

    2016-01-01

    Full Text Available Neisseria elongata (NE is an aerobic Gram-negative organism that constitutes part of the commensal human normal oropharyngeal flora. Although previously considered not to be pathogenic, it has been recognized as an occasional cause of significant infections in humans. We report here the first case in Italy of infective endocarditis of a native prolapsing mitral valve in a patient with Marfan syndrome, caused by NE subspecies nitroreducens which has been rarely isolated from clinical specimens. The culprit organism has been confirmed by mass spectrometry directly from the positive blood culture, as previously reported. The amplified gene has been deposited in GenBank under accession number KT591873. In spite of the reported aggressive nature of NE, clinical remission was promptly obtained, there being no requirement for surgery.

  5. Potential Capsule Switching from Serogroup Y to B: The Characterization of Three such Neisseria meningitidis Isolates Causing Invasive Meningococcal Disease in Canada

    Directory of Open Access Journals (Sweden)

    Raymond SW Tsang

    2005-01-01

    Full Text Available Three group B Neisseria meningitidis isolates, recovered from meningococcal disease cases in Canada and typed as B:2c:P1.5, were characterized. Multilocus sequence typing showed that all three isolates were related because of an identical sequence type (ST 573. Isolates typed as 2c:P1.5 are common in serogroup Y meningococci but rare in isolates from serogroups B or C. Although no serogroup Y isolates have been typed as ST-573, eight isolates showed five to six housekeeping gene alleles that were identical to that of ST-573. This suggested that the B:2c:P1.5 isolates may have originated from serogroup Y organisms, possibly by capsule switching.

  6. Selective testing of women based on age for genital Chlamydia trachomatis and Neisseria gonorrhoeae infection in a centralized regional microbiology laboratory.

    Science.gov (United States)

    Church, Deirdre L; Amante, L; Semeniuk, H; Gregson, D B

    2007-04-01

    Calgary Laboratory Services, Alberta, Canada, provides microbiology services via a centralized laboratory to the Calgary Health Region. A selective genital Chlamydia trachomatis (CT)/Neisseria gonorrhoeae (GC) testing policy for women >35 years was implemented. The changes in physician ordering practice, the rate of detection of infections, and the test turnaround times were monitored. The volume of tests, the cost/test, and the total service costs accrued in the year before and after this policy change were compared. An immediate impact was a 30% decrease in tests performed due to the laboratory rejecting samples from older women. Subsequently, physicians' practice changed so that tests were ordered when test criteria were met. Detection rates did not change in any age group. A 27.9% decrease in the total service costs resulted in a labor reduction of 0.2 FTE. Selective testing of women >35 years with a low prevalence of CT/GC infection is clinically relevant and cost-effective.

  7. In silico analysis of different generation β lactams antibiotics with penicillin binding protein-2 of Neisseria meningitidis for curing meningococcal disease.

    Science.gov (United States)

    Tripathi, Vijay; Tripathi, Pooja; Srivastava, Navita; Gupta, Dwijendra

    2014-12-01

    Neisseria meningitidis is a gram negative, diplococcic pathogen responsible for the meningococcal disease and fulminant septicemia. Penicillin-binding proteins-2 (PBPs) is crucial for the cell wall biosynthesis during cell proliferation of N. meningitidis and these are the target for β-lactam antibiotics. For many years penicillin has been recognized as the antibiotic for meningococcal disease but the meningococcus has seemed to be antibiotic resistance. In the present work we have verified the molecular interaction of Penicillin binding protein-2 N. meningitidis to different generation of β-lactam antibiotics and concluded that the third generation of β-lactam antibiotics shows efficient binding with Penicillin binding protein-2 of N. meningitidis. On the basis of binding efficiency and inhibition constant, ceftazidime emerged as the most efficient antibiotic amongst the other advanced β-lactam antibiotics against Penicillin-binding protein-2 of N. meningitidis.

  8. Two Neisseria meningitidis strains with different ability to stimulate toll-like receptor 4 through the MyD88-independent pathway

    DEFF Research Database (Denmark)

    Mogensen, T.H.; Paludan, Søren Riis; Kilian, Mogens

    2006-01-01

    Neisseria meningitidis causes acute severe diseases, including sepsis and meningitis, and more benign manifestations such as chronic meningococcemia or colonization of the upper respiratory tract. The inflammatory response, which contributes to the pathogenesis of meningococcal disease......, is initiated by pattern recognition receptors, among which Toll-like receptors (TLR)s have been ascribed a particularly important role. We have previously demonstrated that N. meningitidis induce proinflammatory cytokine expression through TLR2 and TLR4. Here we characterize the molecular basis...... for differential activation of the inflammatory response by two N. meningitidis strains. This difference was due to differential ability to activate signal transduction through TLR4, as HEK293 cells expressing TLR4 produced significantly different levels of interleukin-8 in response to these strains. At the level...

  9. Carrier state of Haemophilus influenzae type b (Hib, Streptococcus pneumoniae, Streptococcus pyogenes, Neisseria meningitidis and Corynebacterium diphtheriae among school children in Pokhara, Nepal

    Directory of Open Access Journals (Sweden)

    Dharm Raj Bhatta

    2014-02-01

    Full Text Available Objective: To determine the incidence of carrier state of Haemophilus influenzae type b, Streptococcus pneumoniae (S. pneumoniae, Streptococcus pyogenes, Neisseria meningitidis and Corynebacterium diphtheriae among school children. Methods: Specimen from posterior pharyngeal wall and tonsils were collected on calcium alginate coated swabs from 1 02 participants. Processing of specimen and antimicrobial susceptibility testing was done by standard procedures. Results: Potential pathogens isolated in our study were S. pneumoniae (14.7%, Staphylococcus aureus (12.7%, Corynebacterium diphtheriae (3.9%, Streptococcus pyogenes (3.9% and Haemophilus influenzae (1.9%. Important findings in antibiogram include high resistance of S. pneumoniae to penicillin (73% and resistance of Staphylococcus aureus to oxacillin (23%. Conclusions: Pharyngeal colonization by S. pneumoniae among school children was found high and there is need of introduction of pneumococcal vaccines among children. Despite expected universal vaccination, pharyngeal colonization by Corynebacterium diphtheriae is possible and there is possibility of transmission.

  10. Use of sodC versus ctrA for real-time polymerase chain reaction-based detection of Neisseria meningitidis in sterile body fluids

    Directory of Open Access Journals (Sweden)

    Fábio Takenori Higa

    2013-04-01

    Full Text Available We evaluated the use of a newly described sodC-based real-time-polymerase chain reaction (RT-PCR assay for detecting Neisseria meningitidis in normally sterile sites, such as cerebrospinal fluid and serum. The sodC-based RT-PCR assay has an advantage over ctrA for detecting nongroupable N. meningitidis isolates, which are commonly present in asymptomatic pharyngeal carriage. However, in our study, sodC-based RT-PCR was 7.5% less sensitive than ctrA. Given the public health impact of possible false-negative results due to the use of the sodC target gene alone, sodC-based RT-PCR for the diagnosis of meningococcal meningitis should be used with caution.

  11. SALMONELLA SPECIES

    African Journals Online (AJOL)

    DR. AMINU

    ... of Salmonella species serotypes in relation to age and sex among children, ..... However, most antimicrobials show sufficient selective toxicity to be of value in ... salmonellosis should be given good attention (Barrow et al., 2007). To reduce ...

  12. The structure of lactoferrin-binding protein B from Neisseria meningitidis suggests roles in iron acquisition and neutralization of host defences

    Science.gov (United States)

    Brooks, Cory L.; Arutyunova, Elena; Lemieux, M. Joanne

    2014-01-01

    Pathogens have evolved a range of mechanisms to acquire iron from the host during infection. Several Gram-negative pathogens including members of the genera Neisseria and Moraxella have evolved two-component systems that can extract iron from the host glycoproteins lactoferrin and transferrin. The homologous iron-transport systems consist of a membrane-bound transporter and an accessory lipoprotein. While the mechanism behind iron acquisition from transferrin is well understood, relatively little is known regarding how iron is extracted from lactoferrin. Here, the crystal structure of the N-terminal domain (N-lobe) of the accessory lipoprotein lactoferrin-binding protein B (LbpB) from the pathogen Neisseria meningitidis is reported. The structure is highly homologous to the previously determined structures of the accessory lipoprotein transferrin-binding protein B (TbpB) and LbpB from the bovine pathogen Moraxella bovis. Docking the LbpB structure with lactoferrin reveals extensive binding interactions with the N1 subdomain of lactoferrin. The nature of the interaction precludes apolactoferrin from binding LbpB, ensuring the specificity of iron-loaded lactoferrin. The specificity of LbpB safeguards proper delivery of iron-bound lactoferrin to the transporter lactoferrin-binding protein A (LbpA). The structure also reveals a possible secondary role for LbpB in protecting the bacteria from host defences. Following proteolytic digestion of lactoferrin, a cationic peptide derived from the N-terminus is released. This peptide, called lactoferricin, exhibits potent antimicrobial effects. The docked model of LbpB with lactoferrin reveals that LbpB interacts extensively with the N-terminal lactoferricin region. This may provide a venue for preventing the production of the peptide by proteolysis, or directly sequestering the peptide, protecting the bacteria from the toxic effects of lactoferricin. PMID:25286931

  13. Whole genome typing of the recently emerged Canadian serogroup W Neisseria meningitidis sequence type 11 clonal complex isolates associated with invasive meningococcal disease

    Directory of Open Access Journals (Sweden)

    Raymond S.W. Tsang

    2018-04-01

    Full Text Available Objectives: This study was performed to analyze the Canadian invasive serogroup W Neisseria meningitidis (MenW sequence type 11 (ST-11 clonal complex (CC isolates by whole genome typing and to compare Canadian isolates with similar isolates from elsewhere. Methods: Whole genome typing of 30 MenW ST-11 CC, 20 meningococcal group C (MenC ST-11 CC, and 31 MenW ST-22 CC isolates was performed on the Bacterial Isolate Genome Sequence database platform. Canadian MenW ST-11 CC isolates were compared with the 2000 MenW Hajj outbreak strain, as well as with MenW ST-11 CC from other countries. Results: Whole genome typing showed that the Canadian MenW ST-11 CC isolates were distinct from the traditional MenW ST-22 CC; they were not capsule-switched contemporary MenC strains that incorporated MenW capsules. While some recent MenW disease cases in Canada were caused by MenW ST-11 CC isolates showing relatedness to the 2000 MenW Hajj strain, many were non-Hajj isolates similar to current MenW ST-11 isolates found globally. Geographical and temporal variations in genotypes and surface protein antigen genes were found among the MenW ST-11 CC isolates. Conclusions: The current MenW ST-11 isolates did not arise by capsule switching from contemporary MenC ST-11 isolates. Both the Hajj-related and non-Hajj MenW ST-11 CC strains were associated with invasive meningococcal disease in Canada. Keywords: Neisseria meningitidis, Invasive meningococcal disease, Whole genome typing

  14. Control of gdhR Expression in Neisseria gonorrhoeae via Autoregulation and a Master Repressor (MtrR of a Drug Efflux Pump Operon

    Directory of Open Access Journals (Sweden)

    Corinne E. Rouquette-Loughlin

    2017-04-01

    Full Text Available The MtrCDE efflux pump of Neisseria gonorrhoeae contributes to gonococcal resistance to a number of antibiotics used previously or currently in treatment of gonorrhea, as well as to host-derived antimicrobials that participate in innate defense. Overexpression of the MtrCDE efflux pump increases gonococcal survival and fitness during experimental lower genital tract infection of female mice. Transcription of mtrCDE can be repressed by the DNA-binding protein MtrR, which also acts as a global regulator of genes involved in important metabolic, physiologic, or regulatory processes. Here, we investigated whether a gene downstream of mtrCDE, previously annotated gdhR in Neisseria meningitidis, is a target for regulation by MtrR. In meningococci, GdhR serves as a regulator of genes involved in glucose catabolism, amino acid transport, and biosynthesis, including gdhA, which encodes an l-glutamate dehydrogenase and is located next to gdhR but is transcriptionally divergent. We report here that in N. gonorrhoeae, expression of gdhR is subject to autoregulation by GdhR and direct repression by MtrR. Importantly, loss of GdhR significantly increased gonococcal fitness compared to a complemented mutant strain during experimental murine infection. Interestingly, loss of GdhR did not influence expression of gdhA, as reported for meningococci. This variance is most likely due to differences in promoter localization and utilization between gonococci and meningococci. We propose that transcriptional control of gonococcal genes through the action of MtrR and GdhR contributes to fitness of N. gonorrhoeae during infection.

  15. Antimicrobial susceptibility of Neisseria gonorrhoeae isolates from patients attending a public referral center for sexually transmitted diseases in Belo Horizonte, State of Minas Gerais, Brazil

    Directory of Open Access Journals (Sweden)

    Ligia Maria Bedeschi Costa

    2013-06-01

    Full Text Available Introduction The aim of this study was to determine the antimicrobial susceptibility of Neisseria gonorrhoeae isolates obtained from patients attending a public referral center for sexually transmitted diseases and specialized care services (STD/SCS in Belo Horizonte, Brazil. Methods Between March 2011 and February 2012, 201 specimens of Neisseria gonorrhoeae were consecutively obtained from men with symptoms of urethritis and women with symptons of cervicitis or were obtained during their initial consultation. The strains were tested using the disk diffusion method, and the minimum inhibitory concentrations of azithromycin, cefixime, ceftriaxone, ciprofloxacin, chloramphenicol, penicillin, tetracycline and spectinomycin were determined using the E-test. Results The specimens were 100% sensitive to cefixime, ceftriaxone and spectinomycin and exhibited resistances of 4.5% (9/201, 21.4% (43/201, 11.9% (24/201, 22.4% (45/201 and 32.3% (65/201 to azithromycin, ciprofloxacin, chloramphenicol, penicillin and tetracycline, respectively. Intermediate sensitivities of 17.9% (36/201, 4% (8/201, 16.9% (34/201, 71.1% (143/201 and 22.9% (46/201 were observed for azithromycin, ciprofloxacin, chloramphenicol, penicillin and tetracycline, respectively. The specimens had plasmid-mediated resistance to penicillin PPNG 14.5% (29/201 and tetracycline TRNG 11.5% (23/201. Conclusions The high percentage of detected resistance to penicillin, tetracycline, chloramphenicol and ciprofloxacin indicates that these antibiotics are not appropriate for gonorrhea treatment at the Health Clinic and possibly in Belo Horizonte. The resistance and intermediate sensitivity of these isolates indicates that caution is recommended in the use of azithromycin and emphasizes the need to establish mechanisms for the surveillance of antimicrobial resistance for the effective control of gonorrhea.

  16. The Thioredoxin Domain of Neisseria Gonorrhoeae PilB can use Electrons from DsbD to Reduce Downstream Methionine Sulfoxide Reductases

    Energy Technology Data Exchange (ETDEWEB)

    Brot,N.; Collet, J.; Johnson, L.; Jonsson, T.; Weissbach, H.; Lowther, W.

    2006-01-01

    The PilB protein from Neisseria gonorrhoeae is located in the periplasm and made up of three domains. The N-terminal, thioredoxin-like domain (NT domain) is fused to tandem methionine sulfoxide reductase A and B domains (MsrA/B). We show that the {alpha} domain of Escherichia coli DsbD is able to reduce the oxidized NT domain, which suggests that DsbD in Neisseria can transfer electrons from the cytoplasmic thioredoxin to the periplasm for the reduction of the MsrA/B domains. An analysis of the available complete genomes provides further evidence for this proposition in other bacteria where DsbD/CcdA, Trx, MsrA, and MsrB gene homologs are all located in a gene cluster with a common transcriptional direction. An examination of wild-type PilB and a panel of Cys to Ser mutants of the full-length protein and the individually expressed domains have also shown that the NT domain more efficiently reduces the MsrA/B domains when in the polyprotein context. Within this framework there does not appear to be a preference for the NT domain to reduce the proximal MsrA domain over MsrB domain. Finally, we report the 1.6 {angstrom} crystal structure of the NT domain. This structure confirms the presence of a surface loop that makes it different from other membrane-tethered, Trx-like molecules including TlpA, CcmG and ResA. Subtle differences are observed in this loop when compared to the N. meningitidis NT domain structure. The data taken together supports the formation of specific NT domain interactions with the MsrA/B domains and its in vivo recycling partner, DsbD.

  17. Is the C-terminal insertional signal in Gram-negative bacterial outer membrane proteins species-specific or not?

    Directory of Open Access Journals (Sweden)

    Paramasivam Nagarajan

    2012-09-01

    Full Text Available Abstract Background In Gram-negative bacteria, the outer membrane is composed of an asymmetric lipid bilayer of phopspholipids and lipopolysaccharides, and the transmembrane proteins that reside in this membrane are almost exclusively β-barrel proteins. These proteins are inserted into the membrane by a highly conserved and essential machinery, the BAM complex. It recognizes its substrates, unfolded outer membrane proteins (OMPs, through a C-terminal motif that has been speculated to be species-specific, based on theoretical and experimental results from only two species, Escherichia coli and Neisseria meningitidis, where it was shown on the basis of individual sequences and motifs that OMPs from the one cannot easily be over expressed in the other, unless the C-terminal motif was adapted. In order to determine whether this species specificity is a general phenomenon, we undertook a large-scale bioinformatics study on all predicted OMPs from 437 fully sequenced proteobacterial strains. Results We were able to verify the incompatibility reported between Escherichia coli and Neisseria meningitidis, using clustering techniques based on the pairwise Hellinger distance between sequence spaces for the C-terminal motifs of individual organisms. We noticed that the amino acid position reported to be responsible for this incompatibility between Escherichia coli and Neisseria meningitidis does not play a major role for determining species specificity of OMP recognition by the BAM complex. Instead, we found that the signal is more diffuse, and that for most organism pairs, the difference between the signals is hard to detect. Notable exceptions are the Neisseriales, and Helicobacter spp. For both of these organism groups, we describe the specific sequence requirements that are at the basis of the observed difference. Conclusions Based on the finding that the differences between the recognition motifs of almost all organisms are small, we assume that

  18. Recombinant Protein Truncation Strategy for Inducing Bactericidal Antibodies to the Macrophage Infectivity Potentiator Protein of Neisseria meningitidis and Circumventing Potential Cross-Reactivity with Human FK506-Binding Proteins

    OpenAIRE

    Bielecka, Magdalena K.; Devos, Nathalie; Gilbert, Mélanie; Hung, Miao-Chiu; Weynants, Vincent; Heckels, John E.; Christodoulides, Myron

    2014-01-01

    A recombinant macrophage infectivity potentiator (rMIP) protein of Neisseria meningitidis induces significant serum bactericidal antibody production in mice and is a candidate meningococcal vaccine antigen. However, bioinformatics analysis of MIP showed some amino acid sequence similarity to human FK506-binding proteins (FKBPs) in residues 166 to 252 located in the globular domain of the protein. To circumvent the potential concern over generating antibodies that could recognize human protein...

  19. Metabolismo intermedio e patogenicità microbica: studio della regolazione e dell’espressione differenziale del gene gdhA, codificante la L-glutammato deidrogenasi NADP-specifica, in isolati clinici di Neisseria meningitidis

    OpenAIRE

    Colicchio, Roberta

    2006-01-01

    Neisseria meningitidis (meningococco) è un batterio a ristretto spettro d’ospite e presenta “stili di vita” alternativi: commensale-patogeno, intracellulare-extracellulare. Un fattore cruciale per tale comportamento risiede nella capacità di sintetizzare ed utilizzare nutrienti essenziali per la propria sopravvivenza nei diversi microambienti dell’ospite durante un naturale ciclo infettivo. Dati di letteratura indicano che gdhA, codificante la L-glutammato deidrogenasi NADP-specifica (NADP...

  20. Assets of the non-pathogenic microorganism Dictyostelium discoideum as a model for the study of eukaryotic extracellular vesicles [v1; ref status: indexed, http://f1000r.es/pa

    Directory of Open Access Journals (Sweden)

    Irène Tatischeff

    2013-03-01

    Full Text Available Dictyostelium discoideum microvesicles have recently been presented as a valuable model for eukaryotic extracellular vesicles. Here, the advantages of D. discoideum for unraveling important biological functions of extracellular vesicles in general are detailed. D. discoideum, a non-pathogenic eukaryotic microorganism, belongs to a billion-year-old Amoeboza lineage, which diverged from the animal-fungal lineage after the plant animal-split. During growth and early starvation-induced development, it presents analogies with lymphocytes and macrophages with regard to motility and phagocytosis capability, respectively. Its 6-chromosome genome codes for about 12,500 genes, some showing analogies with human genes. The presence of extracellular vesicles during cell growth has been evidenced as a detoxification mechanism of various structurally unrelated drugs. Controls led to the discovery of constitutive extracellular vesicle secretion in this microorganism, which was an important point. It means that the secretion of extracellular vesicles occurs, in the absence of any drug, during both cell growth and early development. This constitutive secretion of D. discoideum cells is very likely to play a role in intercellular communication. The detoxifying secreted vesicles, which can transport drugs outside the cells, can also act as "Trojan horses", capable of transferring these drugs not only into naïve D. discoideum cells, but into human cells as well. Therefore, these extracellular vesicles were proposed as a new biological drug delivery tool. Moreover, Dictyostelium, chosen by the NIH (USA as a new model organism for biomedical research, has already been used for studying some human diseases. These cells, which are much easier to manipulate than human cells, can be easily designed in simple conditioned medium experiments. Owing to the increasing consensus that extracellular vesicles are probably important mediators of intercellular communication, D

  1. Plant-Associated Symbiotic Burkholderia Species Lack Hallmark Strategies Required in Mammalian Pathogenesis

    Science.gov (United States)

    Fong, Stephanie; Yerrapragada, Shailaja; Estrada-de los Santos, Paulina; Yang, Paul; Song, Nannie; Kano, Stephanie; de Faria, Sergio M.; Dakora, Felix D.; Weinstock, George; Hirsch, Ann M.

    2014-01-01

    Burkholderia is a diverse and dynamic genus, containing pathogenic species as well as species that form complex interactions with plants. Pathogenic strains, such as B. pseudomallei and B. mallei, can cause serious disease in mammals, while other Burkholderia strains are opportunistic pathogens, infecting humans or animals with a compromised immune system. Although some of the opportunistic Burkholderia pathogens are known to promote plant growth and even fix nitrogen, the risk of infection to infants, the elderly, and people who are immunocompromised has not only resulted in a restriction on their use, but has also limited the application of non-pathogenic, symbiotic species, several of which nodulate legume roots or have positive effects on plant growth. However, recent phylogenetic analyses have demonstrated that Burkholderia species separate into distinct lineages, suggesting the possibility for safe use of certain symbiotic species in agricultural contexts. A number of environmental strains that promote plant growth or degrade xenobiotics are also included in the symbiotic lineage. Many of these species have the potential to enhance agriculture in areas where fertilizers are not readily available and may serve in the future as inocula for crops growing in soils impacted by climate change. Here we address the pathogenic potential of several of the symbiotic Burkholderia strains using bioinformatics and functional tests. A series of infection experiments using Caenorhabditis elegans and HeLa cells, as well as genomic characterization of pathogenic loci, show that the risk of opportunistic infection by symbiotic strains such as B. tuberum is extremely low. PMID:24416172

  2. Comparative analyses identified species-specific functional roles in oral microbial genomes

    Science.gov (United States)

    Chen, Tsute; Gajare, Prasad; Olsen, Ingar; Dewhirst, Floyd E.

    2017-01-01

    ABSTRACT The advent of next generation sequencing is producing more genomic sequences for various strains of many human oral microbial species and allows for insightful functional comparisons at both intra- and inter-species levels. This study performed in-silico functional comparisons for currently available genomic sequences of major species associated with periodontitis including Aggregatibacter actinomycetemcomitans (AA), Porphyromonas gingivalis (PG), Treponema denticola (TD), and Tannerella forsythia (TF), as well as several cariogenic and commensal streptococcal species. Complete or draft sequences were annotated with the RAST to infer structured functional subsystems for each genome. The subsystems profiles were clustered to groups of functions with similar patterns. Functional enrichment and depletion were evaluated based on hypergeometric distribution to identify subsystems that are unique or missing between two groups of genomes. Unique or missing metabolic pathways and biological functions were identified in different species. For example, components involved in flagellar motility were found only in the motile species TD, as expected, with few exceptions scattered in several streptococcal species, likely associated with chemotaxis. Transposable elements were only found in the two Bacteroidales species PG and TF, and half of the AA genomes. Genes involved in CRISPR were prevalent in most oral species. Furthermore, prophage related subsystems were also commonly found in most species except for PG and Streptococcus mutans, in which very few genomes contain prophage components. Comparisons between pathogenic (P) and nonpathogenic (NP) genomes also identified genes potentially important for virulence. Two such comparisons were performed between AA (P) and several A. aphrophilus (NP) strains, and between S. mutans + S. sobrinus (P) and other oral streptococcal species (NP). This comparative genomics approach can be readily used to identify functions unique to

  3. Time-Motion Analysis of Four Automated Systems for the Detection of Chlamydia trachomatis and Neisseria gonorrhoeae by Nucleic Acid Amplification Testing.

    Science.gov (United States)

    Williams, James A; Eddleman, Laura; Pantone, Amy; Martinez, Regina; Young, Stephen; Van Der Pol, Barbara

    2014-08-01

    Next-generation diagnostics for Chlamydia trachomatis and Neisseria gonorrhoeae are available on semi- or fully-automated platforms. These systems require less hands-on time than older platforms and are user friendly. Four automated systems, the ABBOTT m2000 system, Becton Dickinson Viper System with XTR Technology, Gen-Probe Tigris DTS system, and Roche cobas 4800 system, were evaluated for total run time, hands-on time, and walk-away time. All of the systems evaluated in this time-motion study were able to complete a diagnostic test run within an 8-h work shift, instrument setup and operation were straightforward and uncomplicated, and walk-away time ranged from approximately 90 to 270 min in a head-to-head comparison of each system. All of the automated systems provide technical staff with increased time to perform other tasks during the run, offer easy expansion of the diagnostic test menu, and have the ability to increase specimen throughput. © 2013 Society for Laboratory Automation and Screening.

  4. Ion torrent personal genome machine sequencing for genomic typing of Neisseria meningitidis for rapid determination of multiple layers of typing information.

    Science.gov (United States)

    Vogel, Ulrich; Szczepanowski, Rafael; Claus, Heike; Jünemann, Sebastian; Prior, Karola; Harmsen, Dag

    2012-06-01

    Neisseria meningitidis causes invasive meningococcal disease in infants, toddlers, and adolescents worldwide. DNA sequence-based typing, including multilocus sequence typing, analysis of genetic determinants of antibiotic resistance, and sequence typing of vaccine antigens, has become the standard for molecular epidemiology of the organism. However, PCR of multiple targets and consecutive Sanger sequencing provide logistic constraints to reference laboratories. Taking advantage of the recent development of benchtop next-generation sequencers (NGSs) and of BIGSdb, a database accommodating and analyzing genome sequence data, we therefore explored the feasibility and accuracy of Ion Torrent Personal Genome Machine (PGM) sequencing for genomic typing of meningococci. Three strains from a previous meningococcus serogroup B community outbreak were selected to compare conventional typing results with data generated by semiconductor chip-based sequencing. In addition, sequencing of the meningococcal type strain MC58 provided information about the general performance of the technology. The PGM technology generated sequence information for all target genes addressed. The results were 100% concordant with conventional typing results, with no further editing being necessary. In addition, the amount of typing information, i.e., nucleotides and target genes analyzed, could be substantially increased by the combined use of genome sequencing and BIGSdb compared to conventional methods. In the near future, affordable and fast benchtop NGS machines like the PGM might enable reference laboratories to switch to genomic typing on a routine basis. This will reduce workloads and rapidly provide information for laboratory surveillance, outbreak investigation, assessment of vaccine preventability, and antibiotic resistance gene monitoring.

  5. Auditing the use and assessing the clinical utility of microscopy as a point-of-care test for Neisseria gonorrhoeae in a Sexual Health clinic.

    Science.gov (United States)

    Mensforth, Sarah; Thorley, Nicola; Radcliffe, Keith

    2018-02-01

    We assessed whether urethral microscopy was performed as per clinic protocol for male clinic attendees reporting contact with Neisseria gonorrhoeae (GC), urethral symptoms or given a diagnosis of epididymo-orchitis (EO) over a 12-month period (9732 patients). Prevalence of gonorrhoea in the contacts, urethral symptoms and EO groups was 50, 12.7 and 1.6%, respectively. Microscopy was performed reliably for contacts (96%), those with discharge/dysuria with evidence of urethritis on examination (98%), but not those with EO (43%). We explored the clinical utility of microscopy as a point-of-care test for identifying urethral GC in each subgroup, using the APTIMA Combo 2 CT/GC nucleic acid amplification test as the comparator (1710 patients). Sensitivity of microscopy for each subgroup was good; there was no statistical difference between subgroup sensitivity using Fisher's exact test. Microscopy is valuable to ensure prompt diagnosis and contact tracing. All GC contacts were treated 'epidemiologically'; however, half of GC contacts did not have GC. Microscopy identified the majority of GC cases, including amongst contacts (71% of heterosexual contacts, 66% of contacts reporting sex with men). We propose that epidemiological treatment for GC contacts should be reconsidered on the grounds of antibiotic stewardship, favouring use of microscopy to guide treatment decisions.

  6. Type I Interferon Induction by Neisseria gonorrhoeae: Dual Requirement of Cyclic GMP-AMP Synthase and Toll-like Receptor 4.

    Science.gov (United States)

    Andrade, Warrison A; Agarwal, Sarika; Mo, Shunyan; Shaffer, Scott A; Dillard, Joseph P; Schmidt, Tobias; Hornung, Veit; Fitzgerald, Katherine A; Kurt-Jones, Evelyn A; Golenbock, Douglas T

    2016-06-14

    The innate immune system is the first line of defense against Neisseria gonorrhoeae (GC). Exposure of cells to GC lipooligosaccharides induces a strong immune response, leading to type I interferon (IFN) production via TLR4/MD-2. In addition to living freely in the extracellular space, GC can invade the cytoplasm to evade detection and elimination. Double-stranded DNA introduced into the cytosol binds and activates the enzyme cyclic-GMP-AMP synthase (cGAS), which produces 2'3'-cGAMP and triggers STING/TBK-1/IRF3 activation, resulting in type I IFN expression. Here, we reveal a cytosolic response to GC DNA that also contributes to type I IFN induction. We demonstrate that complete IFN-β induction by live GC depends on both cGAS and TLR4. Type I IFN is detrimental to the host, and dysregulation of iron homeostasis genes may explain lower bacteria survival in cGAS(-/-) and TLR4(-/-) cells. Collectively, these observations reveal cooperation between TLRs and cGAS in immunity to GC infection. Copyright © 2016. Published by Elsevier Inc.

  7. Type I Interferon Induction by Neisseria gonorrhoeae: Dual Requirement of Cyclic GMP-AMP Synthase and Toll-like Receptor 4

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    Warrison A. Andrade

    2016-06-01

    Full Text Available The innate immune system is the first line of defense against Neisseria gonorrhoeae (GC. Exposure of cells to GC lipooligosaccharides induces a strong immune response, leading to type I interferon (IFN production via TLR4/MD-2. In addition to living freely in the extracellular space, GC can invade the cytoplasm to evade detection and elimination. Double-stranded DNA introduced into the cytosol binds and activates the enzyme cyclic-GMP-AMP synthase (cGAS, which produces 2′3′-cGAMP and triggers STING/TBK-1/IRF3 activation, resulting in type I IFN expression. Here, we reveal a cytosolic response to GC DNA that also contributes to type I IFN induction. We demonstrate that complete IFN-β induction by live GC depends on both cGAS and TLR4. Type I IFN is detrimental to the host, and dysregulation of iron homeostasis genes may explain lower bacteria survival in cGAS−/− and TLR4−/− cells. Collectively, these observations reveal cooperation between TLRs and cGAS in immunity to GC infection.

  8. How the Knowledge of Interactions between Meningococcus and the Human Immune System Has Been Used to Prepare Effective Neisseria meningitidis Vaccines

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    R. Gasparini

    2015-01-01

    Full Text Available In the last decades, tremendous advancement in dissecting the mechanisms of pathogenicity of Neisseria meningitidis at a molecular level has been achieved, exploiting converging approaches of different disciplines, ranging from pathology to microbiology, immunology, and omics sciences (such as genomics and proteomics. Here, we review the molecular biology of the infectious agent and, in particular, its interactions with the immune system, focusing on both the innate and the adaptive responses. Meningococci exploit different mechanisms and complex machineries in order to subvert the immune system and to avoid being killed. Capsular polysaccharide and lipooligosaccharide glycan composition, in particular, play a major role in circumventing immune response. The understanding of these mechanisms has opened new horizons in the field of vaccinology. Nowadays different licensed meningococcal vaccines are available and used: conjugate meningococcal C vaccines, tetravalent conjugate vaccines, an affordable conjugate vaccine against the N. menigitidis serogroup A, and universal vaccines based on multiple antigens each one with a different and peculiar function against meningococcal group B strains.

  9. Genomic Investigation Reveals Highly Conserved, Mosaic, Recombination Events Associated with Capsular Switching among Invasive Neisseria meningitidis Serogroup W Sequence Type (ST)-11 Strains.

    Science.gov (United States)

    Mustapha, Mustapha M; Marsh, Jane W; Krauland, Mary G; Fernandez, Jorge O; de Lemos, Ana Paula S; Dunning Hotopp, Julie C; Wang, Xin; Mayer, Leonard W; Lawrence, Jeffrey G; Hiller, N Luisa; Harrison, Lee H

    2016-07-03

    Neisseria meningitidis is an important cause of meningococcal disease globally. Sequence type (ST)-11 clonal complex (cc11) is a hypervirulent meningococcal lineage historically associated with serogroup C capsule and is believed to have acquired the W capsule through a C to W capsular switching event. We studied the sequence of capsule gene cluster (cps) and adjoining genomic regions of 524 invasive W cc11 strains isolated globally. We identified recombination breakpoints corresponding to two distinct recombination events within W cc11: A 8.4-kb recombinant region likely acquired from W cc22 including the sialic acid/glycosyl-transferase gene, csw resulted in a C→W change in capsular phenotype and a 13.7-kb recombinant segment likely acquired from Y cc23 lineage includes 4.5 kb of cps genes and 8.2 kb downstream of the cps cluster resulting in allelic changes in capsule translocation genes. A vast majority of W cc11 strains (497/524, 94.8%) retain both recombination events as evidenced by sharing identical or very closely related capsular allelic profiles. These data suggest that the W cc11 capsular switch involved two separate recombination events and that current global W cc11 meningococcal disease is caused by strains bearing this mosaic capsular switch. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  10. Duration of polymerase chain reaction-detectable DNA after treatment of Chlamydia trachomatis, Neisseria gonorrhoeae, and Trichomonas vaginalis infections in women.

    Science.gov (United States)

    Williams, James A; Ofner, Susan; Batteiger, Byron E; Fortenberry, J Dennis; Van Der Pol, Barbara

    2014-03-01

    To avoid positive results attributable to residual DNA, the Centers for Disease Control and Prevention recommends avoiding repeat testing with nucleic-acid based tests within 3 weeks after treatment of chlamydial (Chlamydia trachomatis [CT]) or gonococcal (Neisseria gonorrhoeae [GC]) infection. We retrospectively analyzed the duration of detectable DNA from a longitudinal cohort of adolescent women after diagnosis and treatment of infection with CT, GC, or Trichomonas vaginalis (TV). Vaginal swabs were obtained weekly from young women for up to 12 weeks (observation period) after treatment of CT, GC and TV infections. Swabs were tested using a commercially available first generation nucleic acid amplification test (NAAT) for CT and GC, and a laboratory developed NAAT for TV. Kaplan-Meier statistics were used to estimate median time to the first negative DNA-based polymerase chain reaction (PCR) result. Observation periods were available for analysis for 195, 82 and 102 treatments for CT, GC, and TV infection, respectively. Median time to a first negative PCR result for CT, GC, and TV was 9 (range 0-84), 6 (0-76), and 7 (0-84) days, and by day 21, 89%, 95%, and 85% were negative, respectively. Data from this retrospective analysis indicate that greater than 85% of these young women did not have detectable CT, GC, or TV DNA by day 21 post-treatment. This data may be useful to clinicians for patient management and post-treatment testing purposes.

  11. Review and International Recommendation of Methods for Typing Neisseria gonorrhoeae Isolates and Their Implications for Improved Knowledge of Gonococcal Epidemiology, Treatment, and Biology

    Science.gov (United States)

    Unemo, Magnus; Dillon, Jo-Anne R.

    2011-01-01

    Summary: Gonorrhea, which may become untreatable due to multiple resistance to available antibiotics, remains a public health problem worldwide. Precise methods for typing Neisseria gonorrhoeae, together with epidemiological information, are crucial for an enhanced understanding regarding issues involving epidemiology, test of cure and contact tracing, identifying core groups and risk behaviors, and recommending effective antimicrobial treatment, control, and preventive measures. This review evaluates methods for typing N. gonorrhoeae isolates and recommends various methods for different situations. Phenotypic typing methods, as well as some now-outdated DNA-based methods, have limited usefulness in differentiating between strains of N. gonorrhoeae. Genotypic methods based on DNA sequencing are preferred, and the selection of the appropriate genotypic method should be guided by its performance characteristics and whether short-term epidemiology (microepidemiology) or long-term and/or global epidemiology (macroepidemiology) matters are being investigated. Currently, for microepidemiological questions, the best methods for fast, objective, portable, highly discriminatory, reproducible, typeable, and high-throughput characterization are N. gonorrhoeae multiantigen sequence typing (NG-MAST) or full- or extended-length porB gene sequencing. However, pulsed-field gel electrophoresis (PFGE) and Opa typing can be valuable in specific situations, i.e., extreme microepidemiology, despite their limitations. For macroepidemiological studies and phylogenetic studies, DNA sequencing of chromosomal housekeeping genes, such as multilocus sequence typing (MLST), provides a more nuanced understanding. PMID:21734242

  12. Outbreak of Neisseria meningitidis C in workers at a large food-processing plant in Brazil: challenges of controlling disease spread to the larger community.

    Science.gov (United States)

    Iser, B P M; Lima, H C A V; de Moraes, C; de Almeida, R P A; Watanabe, L T; Alves, S L A; Lemos, A P S; Gorla, M C O; Gonçalves, M G; Dos Santos, D A; Sobel, J

    2012-05-01

    SUMMARYAn outbreak of meningococcal disease (MD) with severe morbidity and mortality was investigated in midwestern Brazil in order to identify control measures. A MD case was defined as isolation of Neisseria meningitidis, or detection of polysaccharide antigen in a sterile site, or presence of clinical purpura fulminans, or an epidemiological link with a laboratory-confirmed case-patient, between June and August 2008. In 8 out of 16 MD cases studied, serogroup C ST103 complex was identified. Five (31%) cases had neurological findings and five (31%) died. The attack rate was 12 cases/100 000 town residents and 60 cases/100 000 employees in a large local food-processing plant. We conducted a matched case-control study of eight primary laboratory-confirmed cases (1:4). Factors associated with illness in single variable analysis were work at the processing plant [matched odds ratio (mOR) 22, 95% confidence interval (CI) 2·3-207·7, P10 000 plant employees) stopped propagation in the plant, but not in the larger community.

  13. Interactions of proteoliposomes from serogroup B Neisseria meningitidis with bone marrow-derived dendritic cells and macrophages: adjuvant effects and antigen delivery.

    Science.gov (United States)

    Rodríguez, Tamara; Pérez, Oliver; Ménager, Nathalie; Ugrinovic, Sanja; Bracho, Gustavo; Mastroeni, Pietro

    2005-01-26

    Exposure to proteoliposomes from serogroup B Neisseria meningitidis (PL) induced up-regulation of MHC-II, MHC-I, CD40, CD80 and CD86 expression on the surface of murine bone marrow-derived dendritic cells (DC). CD40, CD80 and CD86 were up-regulated on bone marrow-derived macrophages (MPhi) upon stimulation with PL. Both DC and MPhi released TNFalpha, but only DC produced IL12(p70) in response to PL. A small increase in the expression of MHC-II, CD40 and CD86, as well as production of IL12(p70), was observed on the cell surface of DC, but not MPhi from LPS-non-responder C3H/HeJ after exposure to PL. DC, but not MPhi, incubated with PL containing ovalbumin (PL-OVA) presented OVA-specific peptides to CD4+ and CD8+ OVA-specific T-cell hybridomas. These data clearly indicate that PL exert an immunomodulatory effect on DC and MPhi, with some contribution of non-LPS components besides the main role of LPS. The work also shows the potential of PL as a general system to deliver antigens to DC for presentation to CD4+ and CD8+ T-cells.

  14. Immunological evaluation in nonhuman primates of formulations based on the chimeric protein P64k-domain III of dengue 2 and two components of Neisseria meningitidis.

    Science.gov (United States)

    Valdés, Iris; Hermida, Lisset; Martín, Jorge; Menéndez, Tamara; Gil, Lázaro; Lazo, Laura; Castro, Jorge; Niebla, Olivia; López, Carlos; Bernardo, Lídice; Sánchez, Jorge; Romero, Yaremis; Martínez, Rafael; Guzmán, María G; Guillén, Gerardo

    2009-02-11

    The main problem in the development of successful vaccines against dengue based on recombinant proteins is the necessity to use potent adjuvants to reach a proper functional immune response. Our group reported the expression, characterization and immunological evaluation of the recombinant protein PD5, which contains the domain III of the Envelope protein from dengue 2 virus fused to the carrier protein P64k. This construct completely protected monkeys against viral challenge when the Freund's adjuvant was employed. Therefore, to define suitable formulations for human use, the present work relies on the evaluation of PD5, produced with a high purity and under GMP conditions, when formulated either with outer membrane vesicles (OMV) or the serogroup A capsular polysaccharide (CPS-A) from Neisseria meningitidis, both adsorbed on aluminium hydroxide. The antibody response to the formulation containing the CPS-A was clearly superior to that of the formulation with OMV. The experiment of in vivo protection supported this evidence, since only the group immunized with PD5 and CPS-A was partially protected upon viral challenge. This is the first study in which the polysaccharide A of N. meningitidis is successfully employed as adjuvant for viral antigens.

  15. Genetic diversity of Neisseria meningitidis serogroup C ST-4821 in China based on multiple-locus variable number tandem repeat analysis.

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    Xiaoying Shan

    Full Text Available Neisseria meningitidis sequence type (ST-4821 was first reported in China in 2003, and a new hyper-virulent lineage has been designated as the ST-4821 complex. A large number of N. meningitidis ST-4821 strains have been identified in China since 2003; however, the microevolution characteristics of this complex are unclear. Different combinations of variable number of tandem repeats (VNTR loci were used in multiple-locus VNTR analysis (MLVA to analyze 118 N. meningitidis serogroup C ST-4821 strains isolated from seventeen provinces between 2003 and 2012. Additionally, MLVA with five VNTR loci was performed due to its high discriminatory power. One hundred and eighteen isolates were found to comprise 112 subtypes based on MLVA, and 16 outbreak-associated strains were clustered into one group. These data indicate a high level of diversity for N. meningitidis ST-4821 due to microevolution in the last decade. In addition, the results revealed high similarity between isolates from the same geographic origins, which is helpful when monitoring the spread of N. meningitidis serogroup C ST-4821 and will provide valuable information for the control and prevention of bacterial meningitis in China.

  16. Immunochemical studies and genetic background of two Neisseria meningitidis isolates expressing unusual capsule polysaccharide antigens with specificities of both serogroup Y and W135.

    Science.gov (United States)

    Tsang, Raymond S W; Tsai, Chao Ming; Henderson, Averil M; Tyler, Shaun; Law, Dennis K S; Zollinger, Wendell; Jamieson, Frances

    2008-03-01

    We described 2 unusual Neisseria meningitidis strains isolated from epidemiologically unrelated invasive meningococcal disease cases in Ontario, Canada. Both isolates have features typical of serogroup Y N. meningitidis: are of serotype 2c, are of the multi-locus sequence types typical of the serogroup Y strains in Canada, and are genotyped as serogroup Y based on a previously described PCR-ELISA method that detects the serogroup-Y-specific siaD gene. However, both strains were poly-agglutinable in both anti-Y and anti-W135 antisera. Further studies on 1 of these 2 isolates showed the presence of glucose and galactose as well as sialic acids in its purified capsular polysaccharide, suggesting the presence of both serogroup Y and serogroup W135 polysaccharides. Rabbit antisera produced to this strain contained antibodies to both purified serogroup Y and serogroup W135 capsular polysaccharides. Absorption experiments with either serogroup Y or serogroup W135 bacteria confirmed the presence of antibodies to these 2 different polysaccharides. DNA sequencing of the cps operon from both isolates revealed a siaD gene with 99.7% homology to the published siaD sequence from a serogroup Y strain but with 3 point mutations that all resulted in amino acid changes. How these strains may affect results of routine surveillance, PCR diagnosis, and immuno-protection by vaccination are discussed.

  17. The structure of a contact-dependent growth-inhibition (CDI) immunity protein from Neisseria meningitidis MC58

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    Tan, Kemin; Johnson, Parker M.; Stols, Lucy; Boubion, Bryan; Eschenfeldt, William; Babnigg, Gyorgy; Hayes, Christopher S.; Joachimiak, Andrezj; Goulding, Celia W.

    2015-05-20

    Contact-dependent growth inhibition (CDI) is an important mechanism of intercellular competition between neighboring Gram-negative bacteria. CDI systems encode large surface-exposed CdiA effector proteins that carry a variety of C-terminal toxin domains (CdiA-CTs). All CDI+bacteria also produce CdiI immunity proteins that specifically bind to the cognate CdiA-CT and neutralize its toxin activity to prevent auto-inhibition. Here, the X-ray crystal structure of a CdiI immunity protein fromNeisseria meningitidisMC58 is presented at 1.45 Å resolution. The CdiI protein has structural homology to the Whirly family of RNA-binding proteins, but appears to lack the characteristic nucleic acid-binding motif of this family. Sequence homology suggests that the cognate CdiA-CT is related to the eukaryotic EndoU family of RNA-processing enzymes. A homology model is presented of the CdiA-CT based on the structure of the XendoU nuclease fromXenopus laevis. Molecular-docking simulations predict that the CdiA-CT toxin active site is occluded upon binding to the CdiI immunity protein. Together, these observations suggest that the immunity protein neutralizes toxin activity by preventing access to RNA substrates.

  18. Differential expression of hemoglobin receptor, HmbR, between carriage and invasive isolates of Neisseria meningitidis contributes to virulence: lessons from a clonal outbreak.

    Science.gov (United States)

    Sevestre, Julien; Diene, Seydina M; Aouiti-Trabelsi, Myriam; Deghmane, Ala-Eddine; Tournier, Isabelle; François, Patrice; Caron, François; Taha, Muhamed-Kheir

    2018-04-11

    Carriage and invasion balance in the pathogenesis of Neisseria meningitidis was analyzed during a recent clonal outbreak of meningococcal B in Normandy, France, that offered the opportunity to compare six isolates undistinguable by conventional typing (B:P1.7,16:F3-3/ST-32) isolated from invasive disease or pharyngeal asymptomatic carriage. Data from animal model (transgenic mice rendered susceptible to N. meningitidis infection) showed an absence of virulence for two non-capsulated carriage isolates, an intermediate virulence for two capsulated carriage isolates and a marked virulence for two capsulated invasive isolates. This differential pathogenesis well correlated with whole genome sequencing analysis that clustered together both isolates of each group together, forming their own arm within the Norman cluster. Gene-by-gene analysis specified that genes involved in iron acquisition were among the elements differentially represented in cluster of invasive isolates compared to cluster of capsulated carriage isolates. The hemoglobin receptor encoding gene hmbR was in an ON-phase in the capsulated invasive isolates while carriage capsulated isolates were in an OFF-phase. An ON-phase variant of a capsulated carriage isolate showed enhanced virulence. These data underline the role of phase variation (ON/OFF) of HmbR in the balance between disease isolates/carriage isolates.

  19. Shifts in the Antibiotic Susceptibility, Serogroups, and Clonal Complexes of Neisseria meningitidis in Shanghai, China: A Time Trend Analysis of the Pre-Quinolone and Quinolone Eras.

    Science.gov (United States)

    Chen, Mingliang; Guo, Qinglan; Wang, Ye; Zou, Ying; Wang, Gangyi; Zhang, Xi; Xu, Xiaogang; Zhao, Miao; Hu, Fupin; Qu, Di; Chen, Min; Wang, Minggui

    2015-06-01

    Fluoroquinolones have been used broadly since the end of the 1980s and have been recommended for Neisseria meningitidis prophylaxis since 2005 in China. The aim of this study was to determine whether and how N. meningitidis antimicrobial susceptibility, serogroup prevalence, and clonal complex (CC) prevalence shifted in association with the introduction and expanding use of quinolones in Shanghai, a region with a traditionally high incidence of invasive disease due to N. meningitidis. A total of 374 N. meningitidis isolates collected by the Shanghai Municipal Center for Disease Control and Prevention between 1965 and 2013 were studied. Shifts in the serogroups and CCs were observed, from predominantly serogroup A CC5 (84%) in 1965-1973 to serogroup A CC1 (58%) in 1974-1985, then to serogroup C or B CC4821 (62%) in 2005-2013. The rates of ciprofloxacin nonsusceptibility in N. meningitidis disease isolates increased from 0% in 1965-1985 to 84% (31/37) in 2005-2013 (p convenience isolates from 1965-1985 were available. The increasing prevalence of ciprofloxacin resistance since 2005 in Shanghai was associated with the spread of hypervirulent lineages CC4821 and CC5. Two resistant meningococcal clones ChinaCC4821-R1-C/B and ChinaCC5-R14-A have emerged in Shanghai during the quinolone era. Ciprofloxacin should be utilized with caution for the chemoprophylaxis of N. meningitidis in China.

  20. ATP Induces IL-1β Secretion in Neisseria gonorrhoeae-Infected Human Macrophages by a Mechanism Not Related to the NLRP3/ASC/Caspase-1 Axis

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    Killen García

    2016-01-01

    Full Text Available Neisseria gonorrhoeae (Ngo has developed multiple immune evasion mechanisms involving the innate and adaptive immune responses. Recent findings have reported that Ngo reduces the IL-1β secretion of infected human monocyte-derived macrophages (MDM. Here, we investigate the role of adenosine triphosphate (ATP in production and release of IL-1β in Ngo-infected MDM. We found that the exposure of Ngo-infected MDM to ATP increases IL-1β levels about ten times compared with unexposed Ngo-infected MDM (P0.05 and caspase-1 (CASP1, P>0.05. In addition, ATP was not able to modify caspase-1 activity in Ngo-infected MDM but was able to increase pyroptosis (P>0.01. Notably ATP treatment defined an increase of positive staining for IL-1β with a distinctive intracellular pattern of distribution. Collectively, these data demonstrate that ATP induces IL-1β secretion by a mechanism not related to the NLRP3/ASC/caspase-1 axis and likely is acting at the level of vesicle trafficking or pore formation.

  1. Strong positive selection and recombination drive the antigenic variation of the PilE protein of the human pathogen Neisseria meningitidis.

    Science.gov (United States)

    Andrews, T Daniel; Gojobori, Takashi

    2004-01-01

    The PilE protein is the major component of the Neisseria meningitidis pilus, which is encoded by the pilE/pilS locus that includes an expressed gene and eight homologous silent fragments. The silent gene fragments have been shown to recombine through gene conversion with the expressed gene and thereby provide a means by which novel antigenic variants of the PilE protein can be generated. We have analyzed the evolutionary rate of the pilE gene using the nucleotide sequence of two complete pilE/pilS loci. The very high rate of evolution displayed by the PilE protein appears driven by both recombination and positive selection. Within the semivariable region of the pilE and pilS genes, recombination appears to occur within multiple small sequence blocks that lie between conserved sequence elements. Within the hypervariable region, positive selection was identified from comparison of the silent and expressed genes. The unusual gene conversion mechanism that operates at the pilE/pilS locus is a strategy employed by N. meningitidis to enhance mutation of certain regions of the PilE protein. The silent copies of the gene effectively allow "parallelized" evolution of pilE, thus enabling the encoded protein to rapidly explore a large area of sequence space in an effort to find novel antigenic variants.

  2. Aplicación de una biblioteca de anticuerpos lineales humanos frente al polisacárido capsular de Neisseria meningitidis serogrupo B

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    Emigdio León-Toirac

    2013-12-01

    Full Text Available Neisseria meningitidis serogrupo B produce aún morbimortalidad significativa. Su polisacárido capsular muestra similitud estructural con proteínas humanas y pobre inmunogenicidad, obstaculizando así el desarrollo de vacunas y anticuerpos monoclonales (AcM y policlonales contra esta bacteria. Recientemente se han creado bibliotecas artificiales de anticuerpos humanos expresados en bacteriófagos que reconocen específicamente a moléculas diana existentes, con la ventaja sobre los AcM convencionales por su rápida obtención, sin utilización de animales de laboratorio, lo que emerge como alternativa atractiva para la producción de AcM contra antígenos peculiares o complejos. Se realizó un trabajo de investigación básica, utilizando una biblioteca de fagos filamentosos que expresan constitutivamente regiones variables de anticuerpos humanos, que se enfrentó al polisacárido capsular de N. meningitidis serogrupo B. Los resultados que se obtuvieron mediante ELISA policlonal sugieren la existencia de anticuerpos humanos expresados en fagos que lo reconocen.

  3. Distribution of the type III DNA methyltransferases modA, modB and modD among Neisseria meningitidis genotypes: implications for gene regulation and virulence.

    Science.gov (United States)

    Tan, Aimee; Hill, Dorothea M C; Harrison, Odile B; Srikhanta, Yogitha N; Jennings, Michael P; Maiden, Martin C J; Seib, Kate L

    2016-02-12

    Neisseria meningitidis is a human-specific bacterium that varies in invasive potential. All meningococci are carried in the nasopharynx, and most genotypes are very infrequently associated with invasive meningococcal disease; however, those belonging to the 'hyperinvasive lineages' are more frequently associated with sepsis or meningitis. Genome content is highly conserved between carriage and disease isolates, and differential gene expression has been proposed as a major determinant of the hyperinvasive phenotype. Three phase variable DNA methyltransferases (ModA, ModB and ModD), which mediate epigenetic regulation of distinct phase variable regulons (phasevarions), have been identified in N. meningitidis. Each mod gene has distinct alleles, defined by their Mod DNA recognition domain, and these target and methylate different DNA sequences, thereby regulating distinct gene sets. Here 211 meningococcal carriage and >1,400 disease isolates were surveyed for the distribution of meningococcal mod alleles. While modA11-12 and modB1-2 were found in most isolates, rarer alleles (e.g., modA15, modB4, modD1-6) were specific to particular genotypes as defined by clonal complex. This suggests that phase variable Mod proteins may be associated with distinct phenotypes and hence invasive potential of N. meningitidis strains.

  4. Prevalence of Rickettsia species in Dermacentor variabilis ticks from Ontario, Canada.

    Science.gov (United States)

    Wood, Heidi; Dillon, Liz; Patel, Samir N; Ralevski, Filip

    2016-07-01

    Relatively little is known about the prevalence of rickettsial species in Dermacentor ticks in eastern Canada. In this study, Dermacentor ticks from the province of Ontario, Canada, were tested for the presence of spotted fever group rickettsial (SFGR) species, Coxiella burnetii and Francisella tularensis. Rickettsia rickettsii was not detected in any ticks tested, but R. montanensis was detected at a prevalence of 2.2% in D. variabilis (17/778). Two other SFGR species, R. parkeri and Candidatus R. andeanae, were detected individually in 2 Amblyomma maculatum ticks. Rickettsia peacockii, a non-pathogenic endosymbiont, was detected in two D. andersonii ticks. Given the highly abundant nature of D. variabilis, surveillance for human pathogens in this species of tick has important public health implications, but the lack of detection of known human pathogens indicates a low risk of infection via this tick species in Ontario. However, the detection of R. parkeri in an adventive A. maculatum tick indicates that health care providers should be aware of the possibility of spotted fever rickettsioses in individuals with a history of travel outside of Ontario and symptoms compatible with a spotted fever rickettsiosis. Coxiella burnetii and Francisella tularensis, human pathogens also potentially transmitted by D. variabilis, were not detected in a subset of the ticks. Copyright © 2016 Elsevier GmbH. All rights reserved.

  5. Endangered Species Day | Endangered Species Coalition

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    Annual Top 10 Report Protecting the Endangered Species Act Wildlife Voices Stand for Wolves Endangered Campaigns Wildlife Voices Protecting the Endangered Species Act Annual Top 10 Report Endangered Species Day Stand for Wolves Vanishing BOOK: A Wild Success The Endangered Species Act at 40 Endangered Species The

  6. Molecular Detection of Rickettsia Species Within Ticks (Acari: Ixodidae) Collected from Arkansas United States.

    Science.gov (United States)

    Trout Fryxell, R T; Steelman, C D; Szalanski, A L; Billingsley, P M; Williamson, P C

    2015-05-01

    Rocky Mountain spotted fever (RMSF), caused by the etiological agent Rickettsia rickettsii, is the most severe and frequently reported rickettsial illness in the United States, and is commonly diagnosed throughout the southeast. With the discoveries of Rickettsia parkeri and other spotted fever group rickettsiae (SFGR) in ticks, it remains inconclusive if the cases reported as RMSF are truly caused by R. rickettsii or other SFGR. Arkansas reports one of the highest incidence rates of RMSF in the country; consequently, to identify the rickettsiae in Arkansas, 1,731 ticks, 250 white-tailed deer, and 189 canines were screened by polymerase chain reaction (PCR) for the rickettsial genes gltA, rompB, and ompA. None of the white-tailed deer were positive, while two of the canines (1.1%) and 502 (29.0%) of the ticks were PCR positive. Five different tick species were PCR positive: 244 (37%) Amblyomma americanum L., 130 (38%) Ixodes scapularis Say, 65 (39%) Amblyomma maculatum (Koch), 30 (9%) Rhipicephalus sanguineus Latreille, 7 (4%) Dermacentor variabilis Say, and 26 (44%) unidentified Amblyomma ticks. None of the sequenced products were homologous to R. rickettsii. The most common Rickettsia via rompB amplification was Rickettsia montanensis and nonpathogenic Candidatus Rickettsia amblyommii, whereas with ompA amplification the most common Rickettsia was Ca. R. amblyommii. Many tick specimens collected in northwest Arkansas were PCR positive and these were commonly A. americanum harboring Ca. R. amblyommii, a currently nonpathogenic Rickettsia. Data reported here indicate that pathogenic R. rickettsii was absent from these ticks and suggest by extension that other SFGR are likely the causative agents for Arkansas diagnosed RMSF cases. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  7. Update on antibiotic resistance in foodborne Lactobacillus and Lactococcus species

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    Chiara eDevirgiliis

    2013-10-01

    Full Text Available Lactobacilli represent a major Lactic Acid Bacteria (LAB component within the complex microbiota of fermented foods obtained from meat, dairy and vegetable sources. Lactococci, on the other hand, are typical of milk and fermented dairy products, which in turn represent the vast majority of fermented products. As is the case for all species originating from the environment, foodborne lactobacilli and lactococci consist of natural, uncharacterized strains, whose biodiversity depends on geographical origin, seasonality, animal feeding/plant growth conditions. Although a few species of opportunistic pathogens have been described in lactobacilli and lactococci, they are mostly non-pathogenic, Gram-positive bacteria displaying probiotic features. Since antibiotic resistant (AR strains do not constitute an immediate threat to human health, scientific interest for detailed studies on AR genes in these species has been greatly hindered. However, increasing evidence points at a crucial role for foodborne LAB as reservoir of potentially transmissible AR genes, underlining the need for further, more detailed studies aimed at identifying possible strategies to avoid AR spread to pathogens through fermented food consumption. The availability of a growing number of sequenced bacterial genomes has been very helpful in identifying the presence/distribution of mobile elements associated with AR genes, but open questions and knowledge gaps still need to be filled, underlining the need for systematic and datasharing approaches to implement both surveillance and mechanistic studies on transferability of AR genes. In the present review we report an update of the recent literature on AR in lactobacilli and lactococci following the 2006 EU-wide ban of the use of antibiotics as feed additives in animal farming, and we discuss the limits of the present knowledge in evaluating possible risks for human health.

  8. In Vitro Activity of the New Fluoroketolide Solithromycin (CEM-101) against a Large Collection of Clinical Neisseria gonorrhoeae Isolates and International Reference Strains, Including Those with High-Level Antimicrobial Resistance: Potential Treatment Option for Gonorrhea?

    Science.gov (United States)

    Golparian, Daniel; Fernandes, Prabhavathi; Ohnishi, Makoto; Jensen, Jörgen S.

    2012-01-01

    Gonorrhea may become untreatable, and new treatment options are essential. We investigated the in vitro activity of the first fluoroketolide, solithromycin. Clinical Neisseria gonorrhoeae isolates and reference strains (n = 246), including the two extensively drug-resistant strains H041 and F89 and additional isolates with clinical cephalosporin resistance and multidrug resistance, were examined. The activity of solithromycin was mainly superior to that of other antimicrobials (n = 10) currently or previously recommended for gonorrhea treatment. Solithromycin might be an effective treatment option for gonorrhea. PMID:22354296

  9. In Vivo-Selected Compensatory Mutations Restore the Fitness Cost of Mosaic penA Alleles That Confer Ceftriaxone Resistance in Neisseria gonorrhoeae.

    Science.gov (United States)

    Vincent, Leah R; Kerr, Samuel R; Tan, Yang; Tomberg, Joshua; Raterman, Erica L; Dunning Hotopp, Julie C; Unemo, Magnus; Nicholas, Robert A; Jerse, Ann E

    2018-04-03

    Resistance to ceftriaxone in Neisseria gonorrhoeae is mainly conferred by mosaic penA alleles that encode penicillin-binding protein 2 (PBP2) variants with markedly lower rates of acylation by ceftriaxone. To assess the impact of these mosaic penA alleles on gonococcal fitness, we introduced the mosaic penA alleles from two ceftriaxone-resistant (Cro r ) clinical isolates (H041 and F89) into a Cro s strain (FA19) by allelic exchange and showed that the resultant Cro r mutants were significantly outcompeted by the Cro s parent strain in vitro and in a murine infection model. Four Cro r compensatory mutants of FA19 penA41 were isolated independently from mice that outcompeted the parent strain both in vitro and in vivo One of these compensatory mutants (LV41C) displayed a unique growth profile, with rapid log growth followed by a sharp plateau/gradual decline at stationary phase. Genome sequencing of LV41C revealed a mutation (G348D) in the acnB gene encoding the bifunctional aconitate hydratase 2/2 methylisocitrate dehydratase. Introduction of the acnB G348D allele into FA19 penA41 conferred both a growth profile that phenocopied that of LV41C and a fitness advantage, although not as strongly as that exhibited by the original compensatory mutant, suggesting the existence of additional compensatory mutations. The mutant aconitase appears to be a functional knockout with lower activity and expression than wild-type aconitase. Transcriptome sequencing (RNA-seq) analysis of FA19 penA41 acnB G348D revealed a large set of upregulated genes involved in carbon and energy metabolism. We conclude that compensatory mutations can be selected in Cro r gonococcal strains that increase metabolism to ameliorate their fitness deficit. IMPORTANCE The emergence of ceftriaxone-resistant (Cro r ) Neisseria gonorrhoeae has led to the looming threat of untreatable gonorrhea. Whether Cro resistance is likely to spread can be predicted from studies that compare the relative fitnesses of

  10. Evaluation of sexual history-based screening of anatomic sites for chlamydia trachomatis and neisseria gonorrhoeae infection in men having sex with men in routine practice

    Directory of Open Access Journals (Sweden)

    Jansen Casper L

    2011-07-01

    Full Text Available Abstract Background Sexually transmitted infection (STI screening programmes are implemented in many countries to decrease burden of STI and to improve sexual health. Screening for Chlamydia trachomatis and Neisseria gonorrhoeae has a prominent role in these protocols. Most of the screening programmes concerning men having sex with men (MSM are based on opportunistic urethral testing. In The Netherlands, a history-based approach is used. The aim of this study is to evaluate the protocol of screening anatomic sites for C. trachomatis and N. gonorrhoeae infection based on sexual history in MSM in routine practice in The Netherlands. Methods All MSM visiting the clinic for STI in The Hague are routinely asked about their sexual practice during consulting. As per protocol, tests for urogenital, oropharyngeal and anorectal infection are obtained based on reported site(s of sexual contact. All consultations are entered into a database as part of the national STI monitoring system. Data of an 18 months period were retrieved from this database and analysed. Results A total of 1455 consultations in MSM were registered during the study period. The prevalence of C. trachomatis and N. gonorrhoeae per anatomic site was: urethral infection 4.0% respectively and 2.8%, oropharynx 1.5% and 4.2%, and anorectum 8.2% and 6.0%. The majority of chlamydia cases (72% involved a single anatomic site, which was especially manifest for anorectal infections (79%, while 42% of gonorrhoea cases were single site. Twenty-six percent of MSM with anorectal chlamydia and 17% with anorectal gonorrhoea reported symptoms of proctitis; none of the oropharyngeal infections were symptomatic. Most cases of anorectal infection (83% and oropharyngeal infection (100% would have remained undiagnosed with a symptom-based protocol. Conclusions The current strategy of sexual-history based screening of multiple anatomic sites for chlamydia and gonorrhoea in MSM is a useful and valid guideline

  11. Whole genome typing of the recently emerged Canadian serogroup W Neisseria meningitidis sequence type 11 clonal complex isolates associated with invasive meningococcal disease.

    Science.gov (United States)

    Tsang, Raymond S W; Ahmad, Tauqeer; Tyler, Shaun; Lefebvre, Brigitte; Deeks, Shelley L; Gilca, Rodica; Hoang, Linda; Tyrrell, Gregory; Van Caeseele, Paul; Van Domselaar, Gary; Jamieson, Frances B

    2018-04-01

    This study was performed to analyze the Canadian invasive serogroup W Neisseria meningitidis (MenW) sequence type 11 (ST-11) clonal complex (CC) isolates by whole genome typing and to compare Canadian isolates with similar isolates from elsewhere. Whole genome typing of 30 MenW ST-11 CC, 20 meningococcal group C (MenC) ST-11 CC, and 31 MenW ST-22 CC isolates was performed on the Bacterial Isolate Genome Sequence database platform. Canadian MenW ST-11 CC isolates were compared with the 2000 MenW Hajj outbreak strain, as well as with MenW ST-11 CC from other countries. Whole genome typing showed that the Canadian MenW ST-11 CC isolates were distinct from the traditional MenW ST-22 CC; they were not capsule-switched contemporary MenC strains that incorporated MenW capsules. While some recent MenW disease cases in Canada were caused by MenW ST-11 CC isolates showing relatedness to the 2000 MenW Hajj strain, many were non-Hajj isolates similar to current MenW ST-11 isolates found globally. Geographical and temporal variations in genotypes and surface protein antigen genes were found among the MenW ST-11 CC isolates. The current MenW ST-11 isolates did not arise by capsule switching from contemporary MenC ST-11 isolates. Both the Hajj-related and non-Hajj MenW ST-11 CC strains were associated with invasive meningococcal disease in Canada. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

  12. Remarkable increase of Neisseria gonorrhoeae with decreased susceptibility of azithromycin and increase in the failure of azithromycin therapy in male gonococcal urethritis in Sendai in 2015.

    Science.gov (United States)

    Yasuda, Mitsuru; Ito, Shin; Hatazaki, Kyoko; Deguchi, Takashi

    2016-12-01

    The antimicrobial resistance of Neisseria gonorrhoeae is a serious problem worldwide. In this study, we examined the susceptibility of N. gonorrhoeae isolated from male gonococcal urethritis in Sendai in 2014 and 2015. Furthermore, of all cases, we investigated the clinical efficacy of a single 2-g dose of extended-release azithromycin (AZM-SR) in the treatment of male gonococcal urethritis retrospectively. Sixty N. gonorrhoeae strains in 2014 and 54 strains in 2015 were isolated from male gonococcal urethritis and stored each year. The MIC of AZM was ≥1 mg/L in 4 strains (6.7%) in 2014 and in 13 strains (24.1%) in 2015 and the number of strains having ≥1 mg/L MIC increased significantly (P = 0.016). Microbiological efficacy was evaluated in 32 and 29 of these patients, and the rates of treatment success were 93.8% and 79.3%, respectively. All of the treatment failures were caused by strains having a MIC of AZM of ≥0.5 mg/L. In particular, the increase in the isolates having a MIC of AZM of ≥1 mg/L was remarkable. Therefore, it was thought that the increase in these strains was the reason for the increase in treatment failures in 2015. Because no other drug is effective, it is currently necessary to use AZM-SR to treat gonococcal infections caused by ceftriaxone-resistant strains or patients allergic to ceftriaxone. To prevent a further increase in resistance to AZM, we should not use AZM-SR to treat normal cases of gonococcal infection. Copyright © 2016 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

  13. Structural effect of the Asp345a insertion in penicillin-binding protein 2 from penicillin-resistant strains of Neisseria gonorrhoeae.

    Science.gov (United States)

    Fedarovich, Alena; Cook, Edward; Tomberg, Joshua; Nicholas, Robert A; Davies, Christopher

    2014-12-09

    A hallmark of penicillin-binding protein 2 (PBP2) from penicillin-resistant strains of Neisseria gonorrhoeae is insertion of an aspartate after position 345. The insertion resides on a loop near the active site and is immediately adjacent to an existing aspartate (Asp346) that forms a functionally important hydrogen bond with Ser363 of the SxN conserved motif. Insertion of other amino acids, including Glu and Asn, can also lower the rate of acylation by penicillin, but these insertions abolish transpeptidase function. Although the kinetic consequences of the Asp insertion are well-established, how it impacts the structure of PBP2 is unknown. Here, we report the 2.2 Å resolution crystal structure of a truncated construct of PBP2 containing all five mutations present in PBP2 from the penicillin-resistant strain 6140, including the Asp insertion. Commensurate with the strict specificity for the Asp insertion over similar amino acids, the insertion does not cause disordering of the structure, but rather induces localized flexibility in the β2c-β2d loop. The crystal structure resolves the ambiguity of whether the insertion is Asp345a or Asp346a (due to the adjacent Asp) because the hydrogen bond between Asp346 and Ser362 is preserved and the insertion is therefore Asp346a. The side chain of Asp346a projects directly toward the β-lactam-binding site near Asn364 of the SxN motif. The Asp insertion may lower the rate of acylation by sterically impeding binding of the antibiotic or by hindering breakage of the β-lactam ring during acylation because of the negative charge of its side chain.

  14. The vaginal microbiota and its association with Human Papillomavirus, Chlamydia trachomatis, Neisseria gonorrhea and Mycoplasma genitalium infections: a systematic review and meta-analysis.

    Science.gov (United States)

    Tamarelle, Jeanne; Thiébaut, Anne C M; de Barbeyrac, Bertille; Bébéar, Cécile; Ravel, Jacques; Delarocque-Astagneau, Elisabeth

    2018-05-02

    The vaginal microbiota may modulate susceptibility to Human papillomavirus, Chlamydia trachomatis, Neisseria gonorrhea and Mycoplasma genitalium infections. The objective of this meta-analysis was to evaluate the association between these infections and the vaginal microbiota. The search (2000-2016) yielded 1054 articles, of which 39 articles meeting the inclusion criteria were analyzed. The vaginal microbiota was dichotomized into high-Lactobacillus vaginal microbiota (HL-VMB) and low-Lactobacillus vaginal microbiota (LL-VMB), using either Nugent score, Amsel's criteria, presence of clue cells or gene sequencing. Measures of association with LL-VMB ranged from 0.6 (95% Confidence Interval 0.3, 1.2) to 2.8 (0.3, 28.0), 0.7 (0.4, 1.2) to 5.2 (1.9, 14.8), 0.8 (0.5, 1.4) to 3.8 (0.4, 36.2), and 0.4 (0.1, 1.5) to 6.1 (2.0, 18.5) for HPV, C. trachomatis, N. gonorrhea and M. genitalium infections respectively. While no clear trend for N. gonorrhea and M. genitalium infections could be detected, our results support a protective role of HL-VMB for HPV and C. trachomatis. Overall, these findings advocate for the use of high-resolution characterization methods for the vaginal microbiota to lay the foundation for its integration in prevention and treatment strategies. Copyright © 2018 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

  15. High-Throughput Testing of Urogenital and Extragenital Specimens for Detection of Chlamydia Trachomatis and Neisseria Gonorrhoeae with Cobas® CT/NG.

    Science.gov (United States)

    Marlowe, Elizabeth M; Hardy, David; Krevolin, Mark; Gohl, Peter; Bertram, Alexander; Arcenas, Rodney; Seiverth, Britta; Schneider, Tanja; Liesenfeld, Oliver

    2017-09-01

    We compared the analytical and clinical performance of cobas ® CT/NG for use on the Cobas ® 6800/8800 Systems with the Cobas ® 4800 CT/NG Test from urogenital and extragenital specimens in over 12,000 specimens from both male and female subjects in Germany and the United States. The analytical sensitivity was ≤40 EB/ml for Chlamydia trachomatis (CT) and ≤1 CFU/ml for Neisseria gonorrhoeae (NG). Using clinical specimens, the overall percent agreement with the Cobas ® 4800 CT/NG Test was >98.5%. Across urogenital specimens, there were 93 discrepant specimens; 76 (93.8%) of 81 CT discrepant specimens were 6800+/4800- and 10 (83.3%) of 12 NG discrepant specimens were 6800+/4800-. Sequencing verified CT results for 45 (61.6%) of 73 samples positive by 6800 and 1 (20%) of 5 positive by 4800. Similarly, 7 (70.0%) of 10 NG samples positive by 6800 and 1 of 2 positive by 4800 were confirmed by sequencing. Among discrepant extragenital specimens (all 6800+/4800-), 7 (50%) of 14 oropharyngeal and 23 (76.7%) of 30 anorectal CT discordant samples were confirmed as CT positive by sequencing; all 8 anorectal and 20 (90.9%) of 22 oropharyngeal NG discordant results were also confirmed as NG positive. In conclusion, Cobas ® CT/NG for use on the Cobas ® 6800/8800 Systems provides high-throughput automated solutions for sexually transmitted infection (STI) screening programs.

  16. Utility of pooled urine specimens for detection of Chlamydia trachomatis and Neisseria gonorrhoeae in men attending public sexually transmitted infection clinics in Mumbai, India, by PCR.

    Science.gov (United States)

    Lindan, Christina; Mathur, Meenakshi; Kumta, Sameer; Jerajani, Hermangi; Gogate, Alka; Schachter, Julius; Moncada, Jeanne

    2005-04-01

    Pooling urogenital specimens for the detection of Chlamydia trachomatis and Neisseria gonorrhoeae by nucleic acid amplification tests is an attractive alternative to individual testing. As pooling can reduce the costs of testing as well as labor, it has been advocated for use in resource-poor settings. However, it has neither been widely adopted nor evaluated for use in developing countries. We evaluated the practical use of pooling first-catch urine (FCU) specimens for the detection of C. trachomatis and N. gonorrhoeae from 690 men in Mumbai, India, by PCR. FCU, urethral smears, and swabs were collected from men seen at two sexually transmitted infection (STI) clinics. All laboratory testing was done at the Lokmanya Tilak General Hospital. Gram stain smears and culture isolation for N. gonorrhoeae were performed. Each FCU was tested individually and in pools using the Roche Amplicor PCR for C. trachomatis and N. gonorrhoeae with an internal control for inhibition. Specimen pools consisted of aliquots from five consecutively processed FCUs combined into an amplification tube. An optical density reading of > or =0.20 indicated a pool for which subsequent testing of individual samples was required. Prevalence by PCR on single specimens was 2.2% (15/690) for C. trachomatis and 5.4% (37/690) for N. gonorrhoeae. Compared to individual FCU results, pooling for C. trachomatis and N. gonorrhoeae had an overall sensitivity of 96.1% (50/52). Specificity was 96.5% (83/86) in that three pools required single testing that failed to identify a positive specimen. Pooling missed two positive specimens, decreased the inhibition rate, and saved 50.3% of reagent costs. In this resource-limited setting, the use of pooling to detect C. trachomatis and N. gonorrhoeae by PCR proved to be a simple, accurate, and cost-effective procedure compared to individual testing.

  17. In Vivo-Selected Compensatory Mutations Restore the Fitness Cost of Mosaic penA Alleles That Confer Ceftriaxone Resistance in Neisseria gonorrhoeae

    Directory of Open Access Journals (Sweden)

    Leah R. Vincent

    2018-04-01

    Full Text Available Resistance to ceftriaxone in Neisseria gonorrhoeae is mainly conferred by mosaic penA alleles that encode penicillin-binding protein 2 (PBP2 variants with markedly lower rates of acylation by ceftriaxone. To assess the impact of these mosaic penA alleles on gonococcal fitness, we introduced the mosaic penA alleles from two ceftriaxone-resistant (Cror clinical isolates (H041 and F89 into a Cros strain (FA19 by allelic exchange and showed that the resultant Cror mutants were significantly outcompeted by the Cros parent strain in vitro and in a murine infection model. Four Cror compensatory mutants of FA19 penA41 were isolated independently from mice that outcompeted the parent strain both in vitro and in vivo. One of these compensatory mutants (LV41C displayed a unique growth profile, with rapid log growth followed by a sharp plateau/gradual decline at stationary phase. Genome sequencing of LV41C revealed a mutation (G348D in the acnB gene encoding the bifunctional aconitate hydratase 2/2 methylisocitrate dehydratase. Introduction of the acnBG348D allele into FA19 penA41 conferred both a growth profile that phenocopied that of LV41C and a fitness advantage, although not as strongly as that exhibited by the original compensatory mutant, suggesting the existence of additional compensatory mutations. The mutant aconitase appears to be a functional knockout with lower activity and expression than wild-type aconitase. Transcriptome sequencing (RNA-seq analysis of FA19 penA41 acnBG348D revealed a large set of upregulated genes involved in carbon and energy metabolism. We conclude that compensatory mutations can be selected in Cror gonococcal strains that increase metabolism to ameliorate their fitness deficit.

  18. Inhibition of the dapE-Encoded N-Succinyl-L,L-diaminopimelic Acid Desuccinylase from Neisseria meningitidis by L-Captopril.

    Science.gov (United States)

    Starus, Anna; Nocek, Boguslaw; Bennett, Brian; Larrabee, James A; Shaw, Daniel L; Sae-Lee, Wisath; Russo, Marie T; Gillner, Danuta M; Makowska-Grzyska, Magdalena; Joachimiak, Andrzej; Holz, Richard C

    2015-08-11

    Binding of the competitive inhibitor L-captopril to the dapE-encoded N-succinyl-L,L-diaminopimelic acid desuccinylase from Neisseria meningitidis (NmDapE) was examined by kinetic, spectroscopic, and crystallographic methods. L-Captopril, an angiotensin-converting enzyme (ACE) inhibitor, was previously shown to be a potent inhibitor of the DapE from Haemophilus influenzae (HiDapE) with an IC50 of 3.3 μM and a measured Ki of 1.8 μM and displayed a dose-responsive antibiotic activity toward Escherichia coli. L-Captopril is also a competitive inhibitor of NmDapE with a Ki of 2.8 μM. To examine the nature of the interaction of L-captopril with the dinuclear active site of DapE, we have obtained electron paramagnetic resonance (EPR) and magnetic circular dichroism (MCD) data for the enzymatically hyperactive Co(II)-substituted forms of both HiDapE and NmDapE. EPR and MCD data indicate that the two Co(II) ions in DapE are antiferromagnetically coupled, yielding an S = 0 ground state, and suggest a thiolate bridge between the two metal ions. Verification of a thiolate-bridged dinuclear complex was obtained by determining the three-dimensional X-ray crystal structure of NmDapE in complex with L-captopril at 1.8 Å resolution. Combination of these data provides new insights into binding of L-captopril to the active site of DapE enzymes as well as important inhibitor-active site residue interaction's. Such information is critical for the design of new, potent inhibitors of DapE enzymes.

  19. The prevalence and epidemiology of plasmid-mediated penicillin and tetracycline resistance among Neisseria gonorrhoeae isolates in Guangzhou, China, 2002-2012.

    Science.gov (United States)

    Zheng, Heping; Wu, Xingzhong; Huang, Jinmei; Qin, Xiaolin; Xue, Yaohua; Zeng, Weiying; Lan, Yinyuan; Ou, Jiangli; Tang, Sanmei; Fang, Mingheng

    2015-10-09

    Gonococcal antimicrobial resistance is a global problem. Different resistance plasmids have emerged and spread among the isolates of Neisseria gonorrhoeae worldwide and in China. We conducted this study to monitor the plasmid-mediated penicillin and tetracycline resistance among N. gonorrhoeae isolates in Guangzhou from 2002 to 2012. Consecutive isolates of N. gonorrhoeae were collected from outpatients with gonorrhea attending the STD clinic in Guangdong Provincial Centre for Skin Diseases and STIs Control and Prevention. Penicillinase-producing N. gonorrhoeae (PPNG) isolates were analyzed by the paper acidometric method. Plasmid-mediated resistance to tetracycline in N. gonorrhoeae (TRNG) isolates was screened by the agar plate dilution method. Plasmid types were determined for TRNG and PPNG isolates using polymerase chain reaction (PCR). Minimum inhibitory concentrations (MICs) to penicillin and tetracycline were detected by the agar plate dilution. Of 1378 consecutive N. gonorrhoeae isolates, 429 PPNG and 639 TRNG isolates were identified. The prevalence of PPNG, TRNG, and PPNG/TRNG increased from 18.3 to 47.1 % (χ (2) = 31.57, p penicillin G and tetracycline persisted at high levels and the MIC90s were 32-fold higher than the resistant cutoff point over 11 years. The prevalence rates of penicillin- and tetracycline-resistant N. gonorrhoeae varied from 90.9 to 91.1 % and from 88.3 to 89.3 % during 2002 to 2012, respectively. Resistance to penicillin and tetracycline among N. gonorrhoeae isolates remained at high levels in Guangzhou. The Asian type PPNG continued to spread and Dutch type TRNG was still the dominant strain. The African type PPNG has emerged and is spreading rapidly.

  20. The Design of New Adjuvants for Mucosal Immunity to Neisseria meningitidis B in Nasally Primed Neonatal Mice for Adult Immune Response

    Directory of Open Access Journals (Sweden)

    Tatiane Ferreira

    2012-01-01

    Full Text Available The aim of this study was to determine the value of detoxified Shiga toxins Stx1 and Stx2 (toxoids of Escherichia coli as mucosal adjuvants in neonatal mice for immunogenicity against the outer membrane proteins (OMPs of Neisseria meningitidis B. Mucosal immunization has been shown to be effective for the induction of antigen-specific immune responses in both the systemic and mucosal compartments. Systemic antibody levels (IgG, IgG1, IgG2a, IgG2b, IgM, and IgA and mucosal IgM and IgA were measured by ELISA using an N. meningitidis as an antigen. In addition, IFN-γ and IL-6 production were measured after stimulated proliferation of immune cells. Intranasal administration elicited a higher anti-OMP IgA response in both saliva and vaginal fluids. Our results suggest that both Stx1 and Stx2 toxoids are effective mucosal adjuvants for the induction of Ag-specific IgG, IgM, and IgA antibodies. The toxoids significantly enhanced the IgG and IgM response against OMPs with a potency equivalent to CT, with the response being characterized by both IgG1 and IgG2a isotypes, and increased IFN-gamma production. Additionally, bactericidal activity was induced with IgG and IgM antibodies of high avidity. These results support the use of the new toxoids as potent inducing adjuvants that are particularly suitable for mucosal immunization.

  1. Phenotypic and molecular characterization of Neisseria gonorrhoeae isolates from Slovenia, 2006-12: rise and fall of the multidrug-resistant NG-MAST genogroup 1407 clone?

    Science.gov (United States)

    Jeverica, Samo; Golparian, Daniel; Matičič, Mojca; Potočnik, Marko; Mlakar, Boštjan; Unemo, Magnus

    2014-06-01

    To determine the phenotypic and molecular characteristics of Neisseria gonorrhoeae isolates obtained between 2006 and 2012 in Slovenia. Gonococcal isolates obtained between 2006 and 2012 in Slovenia (n = 194) were investigated with Etest for susceptibility to cefixime, ceftriaxone, penicillin, ciprofloxacin, azithromycin, tetracycline, gentamicin and spectinomycin. All isolates were examined with N. gonorrhoeae multiantigen sequence typing for molecular epidemiology and sequencing of the major extended-spectrum cephalosporin (ESC) resistance determinants (penA, mtrR and penB) was performed. The overall prevalence of decreased susceptibility or resistance to cefixime and ceftriaxone (MIC ≥0.125 mg/L) was 11% and 5%, respectively. The decreased susceptibility or resistance showed an epidemic peak in 2011 (33% for cefixime and 11% for ceftriaxone), decreasing to 6% and 4%, respectively, in 2012. ST1407 (9% of isolates), ST21 (6%) and ST225 (6%) were the most common sequence types (STs) during 2006-12. Genogroup G1407 (ST1407 most prevalent ST), an internationally spread clone with decreased susceptibility or resistance to ESCs, was most prevalent (48%) in 2009. However, the G1407 prevalence then declined: in 2010, 30%; in 2011, 28%; and in 2012, 8%. Instead, in 2012 the ESC- and ciprofloxacin-susceptible G21 was the predominant genogroup (26%). The prevalence of gonococcal resistance to ESCs in Slovenia has been high, but fluctuating. Fortunately, in 2012 some ESC- and ciprofloxacin-susceptible clones, such as genogroups G21, G1195 and G2992, appeared to have mainly replaced the multidrug-resistant G1407 clone, a replacement also seen in several European countries. © The Author 2014. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  2. Prevalence of Trichomonas vaginalis and Coinfection with Chlamydia trachomatis and Neisseria gonorrhoeae in the United States as Determined by the Aptima Trichomonas vaginalis Nucleic Acid Amplification Assay

    Science.gov (United States)

    Chapin, K.; Smith, J. S.; Aslanzadeh, J.; Snook, J.; Hill, C. S.; Gaydos, C. A.

    2012-01-01

    Our aim was to determine Trichomonas vaginalis prevalence using the Aptima Trichomonas vaginalis assay (ATV; Gen-Probe) and the prevalence of Chlamydia trachomatis and Neisseria gonorrhoeae coinfections in U.S. women undergoing screening for C. trachomatis/N. gonorrhoeae. Discarded urogenital samples from 7,593 women (18 to 89 years old) undergoing C. trachomatis/N. gonorrhoeae screening using the Aptima Combo 2 assay (Gen-Probe) in various clinical settings were tested with ATV. Overall, T. vaginalis, C. trachomatis, and N. gonorrhoeae prevalences were 8.7%, 6.7%, and 1.7%, respectively. T. vaginalis was more prevalent than C. trachomatis or N. gonorrhoeae in all age groups except the 18- to 19-year-old group. The highest T. vaginalis prevalence was in women ≥40 years old (>11%), while the highest C. trachomatis prevalence (9.2%) and N. gonorrhoeae prevalence (2.2%) were in women vaginalis, 0.61% for C. trachomatis/N. gonorrhoeae and N. gonorrhoeae/T. vaginalis, and 0.24% for C. trachomatis/N. gonorrhoeae/T. vaginalis and highest in women vaginalis prevalence differed by race/ethnicity, with the highest prevalence in black women (20.2%). T. vaginalis prevalence ranged from 5.4% in family planning clinics to 22.3% in jails. Multivariate analysis determined that ages of ≥40 years, black race, and patient locations were significantly associated with T. vaginalis infection. T. vaginalis is the most common sexually transmitted infection (STI) in women of >40 years, while C. trachomatis and N. gonorrhoeae prevalence is lowest in that age group. Higher T. vaginalis prevalence in women of >40 years is probably attributed to the reason for testing, i.e., symptomatic status versus routine screening in younger women. Coinfections were relatively low. High T. vaginalis prevalence in all age groups suggests that women screened for C. trachomatis/N. gonorrhoeae, whether asymptomatic or symptomatic, should be screened for T. vaginalis. PMID:22622447

  3. Rapid change in the ciprofloxacin resistance pattern among Neisseria gonorrhoeae strains in Nuuk, Greenland: time to reconsider preventive and treatment strategies.

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    Rolskov, Anne Skjerbæk; Bjorn-Mortensen, Karen; Mulvad, Gert; Poulsen, Peter; Jensen, Jørgen Skov; Pedersen, Michael Lynge

    2015-01-01

    Sexually transmitted infections (STIs), including infections with Neisseria gonorrhoeae (GC), are highly incident in Greenland. Since January 2011, GC testing has been performed on urine with nucleic acid amplification tests (NAATs) by strand displacement amplification (Becton Dickinson ProbeTec). Monitoring of GC antibiotic susceptibility by culture was introduced in Nuuk in 2012. Until 2014, no cases of ciprofloxacin-resistant GC strains were reported. In this paper, we report the finding of ciprofloxacin-resistant GC and describe the most recent incidence of GC infections in Greenland. The number of urine NAATs and culture-positive swabs from January to October 2014 were obtained from the Central Laboratory at Queens Ingrid's Hospital in Nuuk and stratified on gender, place and period of testing. Incidence rates were estimated as number of urine NAAT * (12/10) per 100,000 inhabitants. Men in Nuuk with a positive NAAT for GC were encouraged to provide a urethral swab for culture and susceptibility testing. From January to October 2014, a total of 5,436 urine GC NAATs were performed on patients from Nuuk and 9,031 from the rest of Greenland. Of these, 422 (8%) and 820 (9%) were positive, respectively. From January to August, 6 (15%) cultures from Nuuk were ciprofloxacin resistant while in September and October, 26 (59%) were ciprofloxacin resistant (presistance. GC incidence in Nuuk was 3,017 per 100,000 inhabitants per year, compared to 2,491 per 100,000 inhabitants per year in the rest of Greenland. Within a short period, a rapid and dramatic change in ciprofloxacin susceptibility among GC strains isolated in Nuuk was documented and recommendation for first line treatments has changed. Continued monitoring and rethinking of primary and secondary preventive initiatives is highly recommended in this high GC incidence setting.

  4. Cross-species comparison of the Burkholderia pseudomallei, Burkholderia thailandensis, and Burkholderia mallei quorum-sensing regulons.

    Science.gov (United States)

    Majerczyk, Charlotte D; Brittnacher, Mitchell J; Jacobs, Michael A; Armour, Christopher D; Radey, Matthew C; Bunt, Richard; Hayden, Hillary S; Bydalek, Ryland; Greenberg, E Peter

    2014-11-01

    Burkholderia pseudomallei, Burkholderia thailandensis, and Burkholderia mallei (the Bptm group) are close relatives with very different lifestyles: B. pseudomallei is an opportunistic pathogen, B. thailandensis is a nonpathogenic saprophyte, and B. mallei is a host-restricted pathogen. The acyl-homoserine lactone quorum-sensing (QS) systems of these three species show a high level of conservation. We used transcriptome sequencing (RNA-seq) to define the quorum-sensing regulon in each species, and we performed a cross-species analysis of the QS-controlled orthologs. Our analysis revealed a core set of QS-regulated genes in all three species, as well as QS-controlled factors shared by only two species or unique to a given species. This global survey of the QS regulons of B. pseudomallei, B. thailandensis, and B. mallei serves as a platform for predicting which QS-controlled processes might be important in different bacterial niches and contribute to the pathogenesis of B. pseudomallei and B. mallei. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  5. Cross-Species Comparison of the Burkholderia pseudomallei, Burkholderia thailandensis, and Burkholderia mallei Quorum-Sensing Regulons

    Science.gov (United States)

    Majerczyk, Charlotte D.; Brittnacher, Mitchell J.; Jacobs, Michael A.; Armour, Christopher D.; Radey, Matthew C.; Bunt, Richard; Hayden, Hillary S.; Bydalek, Ryland

    2014-01-01

    Burkholderia pseudomallei, Burkholderia thailandensis, and Burkholderia mallei (the Bptm group) are close relatives with very different lifestyles: B. pseudomallei is an opportunistic pathogen, B. thailandensis is a nonpathogenic saprophyte, and B. mallei is a host-restricted pathogen. The acyl-homoserine lactone quorum-sensing (QS) systems of these three species show a high level of conservation. We used transcriptome sequencing (RNA-seq) to define the quorum-sensing regulon in each species, and we performed a cross-species analysis of the QS-controlled orthologs. Our analysis revealed a core set of QS-regulated genes in all three species, as well as QS-controlled factors shared by only two species or unique to a given species. This global survey of the QS regulons of B. pseudomallei, B. thailandensis, and B. mallei serves as a platform for predicting which QS-controlled processes might be important in different bacterial niches and contribute to the pathogenesis of B. pseudomallei and B. mallei. PMID:25182491

  6. Robust species taxonomy assignment algorithm for 16S rRNA NGS reads: application to oral carcinoma samples

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    Nezar Noor Al-Hebshi

    2015-09-01

    Full Text Available Background: Usefulness of next-generation sequencing (NGS in assessing bacteria associated with oral squamous cell carcinoma (OSCC has been undermined by inability to classify reads to the species level. Objective: The purpose of this study was to develop a robust algorithm for species-level classification of NGS reads from oral samples and to pilot test it for profiling bacteria within OSCC tissues. Methods: Bacterial 16S V1-V3 libraries were prepared from three OSCC DNA samples and sequenced using 454's FLX chemistry. High-quality, well-aligned, and non-chimeric reads ≥350 bp were classified using a novel, multi-stage algorithm that involves matching reads to reference sequences in revised versions of the Human Oral Microbiome Database (HOMD, HOMD extended (HOMDEXT, and Greengene Gold (GGG at alignment coverage and percentage identity ≥98%, followed by assignment to species level based on top hit reference sequences. Priority was given to hits in HOMD, then HOMDEXT and finally GGG. Unmatched reads were subject to operational taxonomic unit analysis. Results: Nearly, 92.8% of the reads were matched to updated-HOMD 13.2, 1.83% to trusted-HOMDEXT, and 1.36% to modified-GGG. Of all matched reads, 99.6% were classified to species level. A total of 228 species-level taxa were identified, representing 11 phyla; the most abundant were Proteobacteria, Bacteroidetes, Firmicutes, Fusobacteria, and Actinobacteria. Thirty-five species-level taxa were detected in all samples. On average, Prevotella oris, Neisseria flava, Neisseria flavescens/subflava, Fusobacterium nucleatum ss polymorphum, Aggregatibacter segnis, Streptococcus mitis, and Fusobacterium periodontium were the most abundant. Bacteroides fragilis, a species rarely isolated from the oral cavity, was detected in two samples. Conclusion: This multi-stage algorithm maximizes the fraction of reads classified to the species level while ensuring reliable classification by giving priority to the

  7. Characterization and pathogenicity of Fusarium species associated with leaf spot of mango (Mangifera indica L.).

    Science.gov (United States)

    Omar, Nurul Husna; Mohd, Masratulhawa; Mohamed Nor, Nik Mohd Izham; Zakaria, Latiffah

    2018-01-01

    Leaf spot diseases are mainly caused by fungi including Fusarium. In the present study several species of Fusarium were isolated from the leaf spot lesion of mango (Mangifera indica L.) Based on morphological characteristics, TEF-1α sequences and phylogenetic analysis, five species were identified as F. proliferatum, F. semitectum, F. mangiferae, F. solani and F. chlamydosporum. Pathogenicity test indicated that representative isolates of F. proliferatum, F. semitectum and F. chlamydosporum were pathogenic on mango leaves causing leaf spot with low to moderate virulence. Nevertheless, abundance of spots on the leaf can disrupt photosynthesis which in turn reduced growth, and lead to susceptibility to infection by opportunistic pathogens due to weakening of the plant. Fusarium solani and F. mangiferae were non-pathogenic and it is possible that both species are saprophyte which associated with nutrient availability on the surface of the leaf through decaying leave tissues. The occurrence of Fusarium spp. on the leaf spot lesion and the effect from the disease needs to be considered when developing disease management method of mango cultivation as numerous spot on the leaves could effect the photosynthesis process and finally giving low yield and less quality of mango. Copyright © 2017. Published by Elsevier Ltd.

  8. Methylobacteria isolated from bryophytes and the 2-fold description of the same microbial species.

    Science.gov (United States)

    Schauer, S; Kutschera, U

    2013-02-01

    On the surface of healthy land plants (embryophytes), numerous non-pathogenic bacteria have been discovered and described. Among these epiphytic microbes, pink-pigmented facultative methylotrophic microbes of the genus Methylobacterium are of special significance, because these microorganisms consume methanol emitted via the stomatal pores and secrete growth-promoting phytohormones. Methylobacterium funariae, Schauer and Kutschera 2011, a species isolated in our lab from the common cord moss, described as a nova species in this journal, was recently characterized for a second time as a "new taxon" under a different name, "M. bullatum." Based on a phylogenetic analysis, we show that these taxa are identical. In addition, we provide novel information on the exact cell size, and describe the correct type locality of this bacterial species, which was classified as a phytosymbiont. Finally, we discuss the hypothesis that certain methylobacteria may preferentially colonize bryophytes. With reference to our recent discovery that thalli of ferns form, like liverworts and moss protonemata, associations with methylobacteria, we argue that the haploid phase of cryptogames are preferred host organisms of these pink-pigmented microbial phytosymbionts.

  9. Species concept and speciation

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    Amal Y. Aldhebiani

    2018-03-01

    Full Text Available Defining and recognizing a species has been a controversial issue for a long time. To determine the variation and the limitation between species, many concepts have been proposed. When a taxonomist study a particular taxa, he/she must adopted a species concept and provide a species limitation to define this taxa. In this paper some of species concepts are discussed starting from the typological species concepts to the phylogenetic concept. Positive and negative aspects of these concepts are represented in addition to their application. Keywords: Species concept, Species limitation, Species, Taxonomy, Classification

  10. Neisseria meningitidis differentially controls host cell motility through PilC1 and PilC2 components of type IV Pili.

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    Philippe C Morand

    Full Text Available Neisseria meningitidis is a strictly human pathogen that has two facets since asymptomatic carriage can unpredictably turn into fulminant forms of infection. Meningococcal pathogenesis relies on the ability of the bacteria to break host epithelial or endothelial cellular barriers. Highly restrictive, yet poorly understood, mechanisms allow meningococcal adhesion to cells of only human origin. Adhesion of encapsulated and virulent meningococci to human cells relies on the expression of bacterial type four pili (T4P that trigger intense host cell signalling. Among the components of the meningococcal T4P, the concomitantly expressed PilC1 and PilC2 proteins regulate pili exposure at the bacterial surface, and until now, PilC1 was believed to be specifically responsible for T4P-mediated meningococcal adhesion to human cells. Contrary to previous reports, we show that, like PilC1, the meningococcal PilC2 component is capable of mediating adhesion to human ME180 epithelial cells, with cortical plaque formation and F-actin condensation. However, PilC1 and PilC2 promote different effects on infected cells. Cellular tracking analysis revealed that PilC1-expressing meningococci caused a severe reduction in the motility of infected cells, which was not the case when cells were infected with PilC2-expressing strains. The amount of both total and phosphorylated forms of EGFR was dramatically reduced in cells upon PilC1-mediated infection. In contrast, PilC2-mediated infection did not notably affect the EGFR pathway, and these specificities were shared among unrelated meningococcal strains. These results suggest that meningococci have evolved a highly discriminative tool for differential adhesion in specific microenvironments where different cell types are present. Moreover, the fine-tuning of cellular control through the combined action of two concomitantly expressed, but distinctly regulated, T4P-associated variants of the same molecule (i.e. PilC1 and Pil

  11. Portadores de Neisseria meningitidis, caracterización de las cepas aisladas y respuesta inmune basal a VA-MENGOC-BC

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    María J. Valdés

    2008-08-01

    Full Text Available Con el propósito de conocer la prevalencia de portadores de Neisseria meningitidis en un grupo de adolescentes, los marcadores epidemiológicos de las cepas aisladas, así como los factores de riesgo asociados con el estado de portador y la respuesta inmune basal a VA-MENGOC-BC , se realizó un estudio transversal descriptivo de portadores en 189 estudiantes de 12-19 años de un politécnico de Ciego de Ávila, siguiendo las Normas Bioéticas establecidas. A los estudiantes se les realizó un exudado faríngeo y una extracción de sangre para la obtención de suero, así como una encuesta relacionada con aspectos de la investigación. La identificación de N. meningitidis se hizo por el sistema API NH (bioMérieux. Los serosubtipos e inmunotipos se clasificaron por ELISA de células enteras con anticuerpos monoclonales y la respuesta inmune basal se detectó por el Ensayo Bactericida del Suero. Se determinó la susceptibilidad antimicrobiana de las cepas frente a la penicilina, cloranfenicol, rifampicina, sulfadiacina sódica, ceftriaxona y ciprofloxacina. La prevalencia de portadores de N. meningitidis fue del 17%. Predominaron las cepas no agrupables (84,7%, seguidas por los serogrupos B (12,5% y Z (3,1%, destacándose la ausencia del C. Prevaleció el fenotipo NA:NT:P1.NST:L3,7,9 (12,5%, las cepas resistentes a la sulfadiacina (78,2% y sensibles a penicilina (81,3%, aunque el 18,7% mostró sensibilidad intermedia a este fármaco. Al resto de los antimicrobianos todas fueron sensibles. Se constató una respuesta inmune de memoria a la vacuna antimeningocócica (VAMENGOC-BC®, 12 años después de su aplicación, con títulos bactericidas anti C y B de 25 y 42%, respectivamente, resultados que pudieran estar influenciados por la inmunización sistemática que se realiza en Cuba con esta vacuna desde 1991.

  12. Susceptibilidad antimicrobiana in vitro de cepas de Neisseria gonorrhoeae procesadas en el instituto nacional de salud, Lima, Perú. 1998-1999

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    José Portilla C

    2003-10-01

    Full Text Available Objetivo: Determinar la frecuencia de susceptibilidad y resistencia in vitro de cepas de Neisseria gonorrhoeae, aisladas en el Laboratorio de Bacterias de Transmisión Sexual del Instituto Nacional de Salud, Lima, Perú, frente a los antimicrobianos de uso actual en el tratamiento de la infección por el gonococo; asimismo, conocer la frecuencia con que se presentan las cepas de N. gonorrhoeae productoras de beta-lactamasas. Material y Métodos: Estudio observacional descriptivo. En el Laboratorio de Bacterias de Transmisión Sexual del Instituto Nacional de Salud, Lima, Perú, se recibieron 130 cepas de N. gonorrhoeae (49 en 1998 y 81 en 1999, procedentes de diferentes localidades del país para confirmación bacteriológica. El método de estudio de susceptibilidad antimicrobiana usado fue el de Concentración inhibitoria mínima (CIM frente a la penicilina, espectinomicina, ceftriaxona, cefotaxima, ciprofloxacina y azitromicina. Resultados: La frecuencia de la resistencia de las cepas de N. gonorrhoeae in vitro a la penicilina fue en 15/49 cepas en el año 1998 y 15/81 cepas en el año 1999. Asimismo, la resistencia a la tetraciclina fue en 31/49 cepas en el año 1998 y 51/81 cepas en 1999. El 100% de las cepas estudiadas fueron sensibles a la espectinomicina, ceftriaxona, cefotaxima y ciprofloxacina. En el país, se reporta en 9/81 cepas de N. gonorrhoeae de susceptibilidad disminuida a la azitromicina. Entre los años 1998 y 1999, se reportaron 21/52 y 6/85, respectivamente de cepas de N. gonorrhoeae productoras de beta-lactamasas. Conclusiones: Se encontró resistencia in vitro de cepas de N. gonorrhoeae frente a la penicilina y tetraciclina. Los antibióticos que se deben usar para el tratamiento de la infección son: espectinomicina, ceftriaxona, cefotaxima y ciprofloxacina. Por primer vez se reporta en el país, cepas de susceptibilidad disminuida a la azitromicina.

  13. Caracterización fenotípica de cepas invasivas de Neisseria meningitidis aisladas en Cuba durante 20 años

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    Isabel Martínez

    2006-04-01

    Full Text Available Se investigaron los marcadores epidemiológicos (serogrupos, serotipos, subtipos, inmunotipos de 429 cepas invasivas, aisladas en Cuba durante 20 años (1982-2002. Basándonos en el comportamiento de la incidencia de la Enfermedad Meningocócica (EM en el período investigado, las cepas se distribuyeron en dos etapas: epidémica y postepidémica. La epidémica, comprendió 279 cepas aisladas entre 1982-1992 y la ostepidémica, incluyó 150 aislamientos pertenecientes al período comprendido entre 1993-2002. Todas se cultivaron en Agar Mueller Hinton con suero fetal bovino (5% y se incubaron 24-48 horas, 37 0C, en atmósfera húmeda con 5% de C02. La identificación de género, especie y serogrupo, se realizó mediante métodos convencionales; para la caracterización de los sero/subtipos e inmunotipos, se utilizó el ensayo inmunoenzimático (ELISA de células enteras con anticuerpos monoclonales. En ambas etapas predominó el serogrupo B (97,90%: epidémica (96,77% y postepidémica (100%. Sin embargo, el serogrupo C (1,43% y cepas no agrupables (1,8%, sólo se observaron en aislamientos de la etapa epidémica. Los otros marcadores prevalentes fueron: serotipo 4 (86,48%, subtipo P1.19,15 (78,32%, inmunotipo L3,7,9 (90,2% , todos mostraron cifras similares en ambos períodos.Predominó el fenotipo B:4:P1.19,15:L3,7,9 (69,69%, aunque, en la etapa postepidémica (77,34%, el porcentaje fue superior al de la etapa epidémica (65,66% (p<0,05; además, en las cepas de este período, se observó una mayor diversidad de asociaciones fenotípicas. Los resultados obtenidos de esta caracterización fenotípica de las cepas de Neisseria meningitidis aisladas de enfermos aporta datos valiosos al estudio, prevención y control exitoso de la EM en Cuba.

  14. Predominant porB1A and porB1B genotypes and correlation of gene mutations with drug resistance in Neisseria gonorrhoeae isolates in Eastern China

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    Tang Renxian

    2010-11-01

    Full Text Available Abstract Background Variations of porB1A and porB1B genes and their serotypes exist in Neisseria gonorrhoeae isolates from different geographical areas, and some site mutations in the porB1B gene correlate with drug resistance. Methods The β-lactamase production of N. gonorrhoeae isolates was determined by paper acidometric test and nitrocefin discs. The porB1A and porB1B genes of 315 non-penicillinase-producting N. gonorrhoeae (non-PPNG strains were amplified by PCR for sequencing to determine serotypes and site mutations. A duplex PCR was designed to simultaneously detect both porB1A and porB1B genes. Penicillin and tetracycline resistance was assessed by an in vitro drug sensitivity test. Results Of the N. gonorrhoeae isolates, 31.1% tested positive for porB1A and 68.9% for porB1B genes. All the 98 porB1A+ isolates belonging to IA6 serotype with either no mutation at the 120 and 121 sites (88.8% or a D120G (11.2% mutation and were no resistance to both penicillin and tetracycline. Among the 217 porB1B+ isolates, 26.7%, 22.6% and 11.5% belonged to IB3, IB3/6 and IB4 serotypes, respectively. Particularly, two novel chimeric serotypes, IB3/6-IB2 and IB2-IB4-IB2, were found in 77 and 8 porB1B+ isolates. Two hundred and twelve (97.7% of the porB1B+ isolates were presented G120 and/or A121 mutations with 163 (76.9% at both sites. Interestingly, within the 77 porB1B+ isolates belonging to IB3/6-IB2 serotype, 15 were discovered to possess novel deletions at both A121 and N122 sites. All the replacement mutations at these sites in PorB1B were correlated with resistance and the deletion mutation showed the highest resistance. Conclusion N. gonorrhoeae isolates circulating in Eastern China include a sole PorB1A serotype (IA6 and five PorB1B serotypes. Multiple mutations in porB1B genes, including novel A121 and N122 deletions, are correlated with high levels of penicillin and tetracycline resistance.

  15. Neisseria gonorrhoeae Sequence Typing for Antimicrobial Resistance, a Novel Antimicrobial Resistance Multilocus Typing Scheme for Tracking Global Dissemination of N. gonorrhoeae Strains.

    Science.gov (United States)

    Demczuk, W; Sidhu, S; Unemo, M; Whiley, D M; Allen, V G; Dillon, J R; Cole, M; Seah, C; Trembizki, E; Trees, D L; Kersh, E N; Abrams, A J; de Vries, H J C; van Dam, A P; Medina, I; Bharat, A; Mulvey, M R; Van Domselaar, G; Martin, I

    2017-05-01

    A curated Web-based user-friendly sequence typing tool based on antimicrobial resistance determinants in Neisseria gonorrhoeae was developed and is publicly accessible (https://ngstar.canada.ca). The N. gonorrhoeae Sequence Typing for Antimicrobial Resistance (NG-STAR) molecular typing scheme uses the DNA sequences of 7 genes ( penA , mtrR , porB , ponA , gyrA , parC , and 23S rRNA) associated with resistance to β-lactam antimicrobials, macrolides, or fluoroquinolones. NG-STAR uses the entire penA sequence, combining the historical nomenclature for penA types I to XXXVIII with novel nucleotide sequence designations; the full mtrR sequence and a portion of its promoter region; portions of ponA , porB , gyrA , and parC ; and 23S rRNA sequences. NG-STAR grouped 768 isolates into 139 sequence types (STs) ( n = 660) consisting of 29 clonal complexes (CCs) having a maximum of a single-locus variation, and 76 NG-STAR STs ( n = 109) were identified as unrelated singletons. NG-STAR had a high Simpson's diversity index value of 96.5% (95% confidence interval [CI] = 0.959 to 0.969). The most common STs were NG-STAR ST-90 ( n = 100; 13.0%), ST-42 and ST-91 ( n = 45; 5.9%), ST-64 ( n = 44; 5.72%), and ST-139 ( n = 42; 5.5%). Decreased susceptibility to azithromycin was associated with NG-STAR ST-58, ST-61, ST-64, ST-79, ST-91, and ST-139 ( n = 156; 92.3%); decreased susceptibility to cephalosporins was associated with NG-STAR ST-90, ST-91, and ST-97 ( n = 162; 94.2%); and ciprofloxacin resistance was associated with NG-STAR ST-26, ST-90, ST-91, ST-97, ST-150, and ST-158 ( n = 196; 98.0%). All isolates of NG-STAR ST-42, ST-43, ST-63, ST-81, and ST-160 ( n = 106) were susceptible to all four antimicrobials. The standardization of nomenclature associated with antimicrobial resistance determinants through an internationally available database will facilitate the monitoring of the global dissemination of antimicrobial-resistant N. gonorrhoeae strains. © Crown copyright 2017.

  16. Susceptibility of Neisseria gonorrhoeae to azithromycin and ceftriaxone in China: A retrospective study of national surveillance data from 2013 to 2016.

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    Yue-Ping Yin

    2018-02-01

    Full Text Available Gonorrhea remains one of the most common sexually transmitted diseases worldwide. Successful treatment has been hampered by emerging resistance to each of the antibiotics recommended as first-line therapies. We retrospectively analyzed the susceptibility of gonorrhea to azithromycin and ceftriaxone using data from the China Gonococcal Resistance Surveillance Programme (China-GRSP in order to provide evidence for updating the treatment recommendations in China.In this study, we included 3,849 isolates collected from patients with a confirmed positive Neisseria gonorrhoeae (N. gonorrhoeae culture at clinic visits during the period of 1 January 2013 through 31 December 2016 in 7 provinces. Antimicrobial susceptibility testing of gonorrhea isolates using agar dilution was conducted to determine minimum inhibitory concentration (MIC. Resistance to azithromycin (RTA was defined as MIC ≥ 1.0 mg/l, and decreased susceptibility to ceftriaxone (DSC was defined as MIC ≥ 0.125 mg/l. The prevalence of isolates with RTA was 18.6% (710/3,827; 95% CI 17.4%-19.8%. The percentage of patients with DSC fluctuated between 9.7% and 12.2% over this period. The overall prevalence of isolates with both RTA and DSC was 2.3% (87/3,827; 95% CI 1.9%-2.8% and it increased from 1.9% in 2013 to 3.3% in 2016 (chi-squared test for trend, P = 0.03. Study limitations include the retrospective study design and potential biases in the sample, which may overrepresent men with symptomatic infection, coastal residents, and people reporting as heterosexual.To our knowledge, this is the first national study on susceptibility of N. gonorrhoeae to azithromycin and ceftriaxone in China. Our findings indicate high rates of RTA and DSC from 2013 to 2016. Although dual therapy with azithromycin and ceftriaxone has been recommended by WHO and many countries to treat gonorrhea, reevaluation of this therapy is needed prior to its introduction in China.

  17. Association of Neisseria gonorrhoeae Opa(CEA with dendritic cells suppresses their ability to elicit an HIV-1-specific T cell memory response.

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    Qigui Yu

    Full Text Available Infection with Neisseria gonorrhoeae (N. gonorrhoeae can trigger an intense local inflammatory response at the site of infection, yet there is little specific immune response or development of immune memory. Gonococcal surface epitopes are known to undergo antigenic variation; however, this is unlikely to explain the weak immune response to infection since individuals can be re-infected by the same serotype. Previous studies have demonstrated that the colony opacity-associated (Opa proteins on the N. gonorrhoeae surface can bind human carcinoembryonic antigen-related cellular adhesion molecule 1 (CEACAM1 on CD4⁺ T cells to suppress T cell activation and proliferation. Interesting in this regard, N. gonorrhoeae infection is associated with impaired HIV-1 (human immunodeficiency virus type 1-specific cytotoxic T-lymphocyte (CTL responses and with transient increases in plasma viremia in HIV-1-infected patients, suggesting that N. gonorrhoeae may also subvert immune responses to co-pathogens. Since dendritic cells (DCs are professional antigen presenting cells (APCs that play a key role in the induction of an adaptive immune response, we investigated the effects of N. gonorrhoeae Opa proteins on human DC activation and function. While morphological changes reminiscent of DC maturation were evident upon N. gonorrhoeae infection, we observed a marked downregulation of DC maturation marker CD83 when the gonococci expressing CEACAM1-specific Opa(CEA, but not other Opa variants. Consistent with a gonococcal-induced defect in maturation, Opa(CEA binding to CEACAM1 reduced the DCs' capacity to stimulate an allogeneic T cell proliferative response. Moreover, Opa(CEA-expressing N. gonorrhoeae showed the potential to impair DC-dependent development of specific adaptive immunity, since infection with Opa(CEA-positive gonococci suppressed the ability of DCs to stimulate HIV-1-specific memory CTL responses. These results reveal a novel mechanism to explain

  18. Immunization and chemical conjugation of Bm95 obtained from Pichia pastoris enhances the immune response against vaccinal protein and Neisseria meningitidis capsular polysaccharide

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    Rodriguez-Valle M

    2014-03-01

    Full Text Available Manuel Rodriguez-Valle,1 Leonardo Canan-Hadden,2 Olivia Niebla2 1Animal Biotechnology Division, 2Analytical Division, Centre for Genetic Engineering and Biotechnology, Havana, Cuba Abstract: The ectoparasite Rhipicephalus (Boophilus microplus causes severe economic losses to the cattle industry in tropical and subtropical regions, and transmits endoparasites, such as Babesia bovis. The glycoprotein Bm95 is homologous to Bm86, a surface membrane protein of gut epithelial cells in R. microplus, and has been shown to efficiently control this ectoparasite in regions of the Americas. The immunostimulant properties of Bm86 have already been demonstrated after its coinjection with hepatitis B surface antigen (HBsAg and the infectious bovine rhinotracheitis virus. This study evaluated the carrier and immunostimulant properties of Bm95 using low immunogenic Neisseria meningitidis capsular C polysaccharide (Men CpS and HBsAg. We produced two polysaccharide-Bm95 conjugates by carbodiimide (MenCpSBm-c and reductive amination (MenCpSBm-ra methods. These conjugates were characterized and evaluated in mice. Antibody titers against Men CpS were significantly higher in mice immunized with MenCpSBm-ra (2,350±250, P<0.01 than in those immunized with MenCpSBm-c (250±75 or Men CpS (570±104. The study data indicate effective immunological memory after booster inoculation in mice immunized with MenCpSBm-ra. Additionally, significant humoral immunity against HBsAg was documented in mice coimmunized via the intranasal route with recombinant Bm95 (11,400±345 and HBsAg (128,000±250 compared with mice immunized only with HBsAg (400±40 or Bm95 (5,461±150, P<0.01. In conclusion, the immunostimulatory properties of recombinant Bm95 make it a useful element for developing safer conjugated vaccines against bacterial pathogens and for evaluation against ticks and tick-borne diseases in the context of a polyvalent veterinary vaccine. Keywords: glycoconjugate, Bm86

  19. Multiplex quantitative PCR for detection of lower respiratory tract infection and meningitis caused by Streptococcus pneumoniae, Haemophilus influenzae and Neisseria meningitidis.

    Science.gov (United States)

    Abdeldaim, Guma M K; Strålin, Kristoffer; Korsgaard, Jens; Blomberg, Jonas; Welinder-Olsson, Christina; Herrmann, Björn

    2010-12-03

    Streptococcus pneumoniae and Haemophilus influenzae cause pneumonia and as Neisseria meningitidis they are important agents of meningitis. Although several PCR methods have been described for these bacteria the specificity is an underestimated problem. Here we present a quantitative multiplex real-time PCR (qmPCR) for detection of S. pneumoniae (9802 gene fragment), H. influenzae (omp P6 gene) and N. meningitidis (ctrA gene). The method was evaluated on bronchoalveolar lavage (BAL) samples from 156 adults with lower respiratory tract infection (LRTI) and 31 controls, and on 87 cerebrospinal fluid (CSF) samples from meningitis patients. The analytical sensitivity was not affected by using a combined mixture of reagents and a combined DNA standard (S. pneumoniae/H. influenzae/N. meningitidis) in single tubes. By blood- and BAL-culture and S. pneumoniae urinary antigen test, S. pneumoniae and H. influenzae were aetiological agents in 21 and 31 of the LTRI patients, respectively. These pathogens were identified by qmPCR in 52 and 72 of the cases, respectively, yielding sensitivities and specificities of 95% and 75% for S. pneumoniae, and 90% and 65% for H. influenzae, respectively. When using a cut-off of 10⁵ genome copies/mL for clinical positivity the sensitivities and specificities were 90% and 80% for S. pneumoniae, and 81% and 85% for H. influenzae, respectively. Of 44 culture negative but qmPCR positive for H. influenzae, 41 were confirmed by fucK PCR as H. influenzae. Of the 103 patients who had taken antibiotics prior to sampling, S. pneumoniae and H. influenzae were identified by culture in 6% and 20% of the cases, respectively, and by the qmPCR in 36% and 53% of the cases, respectively.In 87 CSF samples S. pneumoniae and N. meningitidis were identified by culture and/or 16 S rRNA in 14 and 10 samples and by qmPCR in 14 and 10 samples, respectively, giving a sensitivity of 100% and a specificity of 100% for both bacteria. The PCR provides increased

  20. Multiplex quantitative PCR for detection of lower respiratory tract infection and meningitis caused by Streptococcus pneumoniae, Haemophilus influenzae and Neisseria meningitidis

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    Welinder-Olsson Christina

    2010-12-01

    Full Text Available Abstract Background Streptococcus pneumoniae and Haemophilus influenzae cause pneumonia and as Neisseria meningitidis they are important agents of meningitis. Although several PCR methods have been described for these bacteria the specificity is an underestimated problem. Here we present a quantitative multiplex real-time PCR (qmPCR for detection of S. pneumoniae (9802 gene fragment, H. influenzae (omp P6 gene and N. meningitidis (ctrA gene. The method was evaluated on bronchoalveolar lavage (BAL samples from 156 adults with lower respiratory tract infection (LRTI and 31 controls, and on 87 cerebrospinal fluid (CSF samples from meningitis patients. Results The analytical sensitivity was not affected by using a combined mixture of reagents and a combined DNA standard (S. pneumoniae/H. influenzae/N. meningitidis in single tubes. By blood- and BAL-culture and S. pneumoniae urinary antigen test, S. pneumoniae and H. influenzae were aetiological agents in 21 and 31 of the LTRI patients, respectively. These pathogens were identified by qmPCR in 52 and 72 of the cases, respectively, yielding sensitivities and specificities of 95% and 75% for S. pneumoniae, and 90% and 65% for H. influenzae, respectively. When using a cut-off of 105 genome copies/mL for clinical positivity the sensitivities and specificities were 90% and 80% for S. pneumoniae, and 81% and 85% for H. influenzae, respectively. Of 44 culture negative but qmPCR positive for H. influenzae, 41 were confirmed by fucK PCR as H. influenzae. Of the 103 patients who had taken antibiotics prior to sampling, S. pneumoniae and H. influenzae were identified by culture in 6% and 20% of the cases, respectively, and by the qmPCR in 36% and 53% of the cases, respectively. In 87 CSF samples S. pneumoniae and N. meningitidis were identified by culture and/or 16 S rRNA in 14 and 10 samples and by qmPCR in 14 and 10 samples, respectively, giving a sensitivity of 100% and a specificity of 100% for both

  1. Shifts in the Antibiotic Susceptibility, Serogroups, and Clonal Complexes of Neisseria meningitidis in Shanghai, China: A Time Trend Analysis of the Pre-Quinolone and Quinolone Eras.

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    Mingliang Chen

    2015-06-01

    Full Text Available Fluoroquinolones have been used broadly since the end of the 1980s and have been recommended for Neisseria meningitidis prophylaxis since 2005 in China. The aim of this study was to determine whether and how N. meningitidis antimicrobial susceptibility, serogroup prevalence, and clonal complex (CC prevalence shifted in association with the introduction and expanding use of quinolones in Shanghai, a region with a traditionally high incidence of invasive disease due to N. meningitidis.A total of 374 N. meningitidis isolates collected by the Shanghai Municipal Center for Disease Control and Prevention between 1965 and 2013 were studied. Shifts in the serogroups and CCs were observed, from predominantly serogroup A CC5 (84% in 1965-1973 to serogroup A CC1 (58% in 1974-1985, then to serogroup C or B CC4821 (62% in 2005-2013. The rates of ciprofloxacin nonsusceptibility in N. meningitidis disease isolates increased from 0% in 1965-1985 to 84% (31/37 in 2005-2013 (p < 0.001. Among the ciprofloxacin-nonsusceptible isolates, 87% (27/31 were assigned to either CC4821 (n = 20 or CC5 (n = 7. The two predominant ciprofloxacin-resistant clones were designated ChinaCC4821-R1-C/B and ChinaCC5-R14-A. The ChinaCC4821-R1-C/B clone acquired ciprofloxacin resistance by a point mutation, and was present in 52% (16/31 of the ciprofloxacin-nonsusceptible disease isolates. The ChinaCC5-R14-A clone acquired ciprofloxacin resistance by horizontal gene transfer, and was found in 23% (7/31 of the ciprofloxacin-nonsusceptible disease isolates. The ciprofloxacin nonsusceptibility rate was 47% (7/15 among isolates from asymptomatic carriers, and nonsusceptibility was associated with diverse multi-locus sequence typing profiles and pulsed-field gel electrophoresis patterns. As detected after 2005, ciprofloxacin-nonsusceptible strains were shared between some of the patients and their close contacts. A limitation of this study is that isolates from 1986-2004 were not available

  2. Co-ordinate action of bacterial adhesins and human carcinoembryonic antigen receptors in enhanced cellular invasion by capsulate serum resistant Neisseria meningitidis.

    Science.gov (United States)

    Rowe, Helen A; Griffiths, Natalie J; Hill, Darryl J; Virji, Mumtaz

    2007-01-01

    Neisseria meningitidis (Nm) is a human specific opportunistic pathogen that occasionally penetrates mucosal barriers via the action of adhesins and invasins and evades host immune mechanisms during further dissemination via capsule expression. From in vitro studies, the primary adhesion of capsulate bacteria is believed to be mediated by polymeric pili, followed by invasion via outer membrane adhesins such as Opa proteins. As the latter requires the surface capsule to be down-modulated, invading bacteria would be serum sensitive and thus avirulent. However, there is recent evidence that capsulate bacteria may interact via Opa proteins when host cells express high levels of carcinoembryonic antigen-related cell adhesion molecules (CEACAMs), their target receptors. Such a situation may arise following increased circulation of inflammatory cytokines that upregulate certain adhesion molecules on host cells. In this study, using a tetracycline controlled expression system, we have developed cell lines with inducible CEACAM expression to mimic post-inflammation state of target tissues and analysed the interplay between the three surface components capsule, pili and Opa proteins in cellular interactions. With two distinct cell lines, not only the level but also the rate of adhesion of capsulate Opa-expressing Nm increased concurrently with CEACAM density. Moreover, when threshold levels of receptor were reached, cellular invasion ensued in an Opa-dependent manner. In studies with cell lines intrinsically expressing pilus receptors, notable synergism in cellular interactions between pili and Opa of several meningococcal strains was observed and was independent of capsule type. A number of internalized bacteria were shown to express capsule and when directly isolated from host cells, these bacteria were as serum resistant as the inoculated phenotype. Furthermore, we observed that agents that block Opa-CEACAM binding substantially reduced cellular invasion, while maintaining

  3. Neisseria meningitidis elicits a pro-inflammatory response involving IκBζ in a human blood-cerebrospinal fluid barrier model.

    Science.gov (United States)

    Borkowski, Julia; Li, Li; Steinmann, Ulrike; Quednau, Natascha; Stump-Guthier, Carolin; Weiss, Christel; Findeisen, Peter; Gretz, Norbert; Ishikawa, Hiroshi; Tenenbaum, Tobias; Schroten, Horst; Schwerk, Christian

    2014-09-13

    The human-specific, Gram-negative bacterium Neisseria meningitidis (Nm) is a leading cause of bacterial meningitis worldwide. The blood-cerebrospinal fluid barrier (BCSFB), which is constituted by the epithelial cells of the choroid plexus (CP), has been suggested as one of the potential entry sites of Nm into the CSF and can contribute to the inflammatory response during infectious diseases of the brain. Toll-like receptors (TLRs) are involved in mediating signal transduction caused by the pathogens. Using a recently established in vitro model of the human BCSFB based on human malignant CP papilloma (HIBCPP) cells we investigated the cellular response of HIBCPP cells challenged with the meningitis-causing Nm strain, MC58, employing transcriptome and RT-PCR analysis, cytokine bead array, and enzyme-linked immunosorbent assay (ELISA). In comparison, we analyzed the answer to the closely related unencapsulated carrier isolate Nm α14. The presence of TLRs in HIBCPP and their role during signal transduction caused by Nm was studied by RT-PCR and the use of specific agonists and mutant bacteria. We observed a stronger transcriptional response after infection with strain MC58, in particular with its capsule-deficient mutant MC58siaD-, which correlated with bacterial invasion levels. Expression evaluation and Gene Set Enrichment Analysis pointed to a NFκB-mediated pro-inflammatory immune response involving up-regulation of the transcription factor IκBζ. Infected cells secreted significant levels of pro-inflammatory chemokines and cytokines, including, among others, IL8, CXCL1-3, and the IκBζ target gene product IL6. The expression profile of pattern recognition receptors in HIBCPP cells and the response to specific agonists indicates that TLR2/TLR6, rather than TLR4 or TLR2/TLR1, is involved in the cellular reaction following Nm infection. Our data show that Nm can initiate a pro-inflammatory response in human CP epithelial cells probably involving TLR2/TLR6

  4. Species accounts. Chapter 4

    Science.gov (United States)

    Margaret K. Trani; W. Mark Ford; Brian R., eds. Chapman

    2007-01-01

    Narrative accounts for each species are presented by several authors in a consistent format to convey specific information relative to that mammal. The orders are arranged phylogenetically; families and species are arranged alphabetically to facilitate finding a particular species.

  5. Molecular Mapping to Species Level of the Tonsillar Crypt Microbiota Associated with Health and Recurrent Tonsillitis

    Science.gov (United States)

    Jensen, Anders; Fagö-Olsen, Helena; Sørensen, Christian Hjort; Kilian, Mogens

    2013-01-01

    The human palatine tonsils, which belong to the central antigen handling sites of the mucosal immune system, are frequently affected by acute and recurrent infections. This study compared the microbiota of the tonsillar crypts in children and adults affected by recurrent tonsillitis with that of healthy adults and children with tonsillar hyperplasia. An in-depth 16S rRNA gene based pyrosequencing approach combined with a novel strategy that included phylogenetic analysis and detection of species-specific sequence signatures enabled identification of the major part of the microbiota to species level. A complex microbiota consisting of between 42 and 110 taxa was demonstrated in both children and adults. This included a core microbiome of 12 abundant genera found in all samples regardless of age and health status. Yet, Haemophilus influenzae, Neisseria species, and Streptococcus pneumoniae were almost exclusively detected in children. In contrast, Streptococcus pseudopneumoniae was present in all samples. Obligate anaerobes like Porphyromonas, Prevotella, and Fusobacterium were abundantly present in children, but the species diversity of Porphyromonas and Prevotella was larger in adults and included species that are considered putative pathogens in periodontal diseases, i.e. Porphyromonas gingivalis, Porphyromonas endodontalis, and Tannerella forsythia. Unifrac analysis showed that recurrent tonsillitis is associated with a shift in the microbiota of the tonsillar crypts. Fusobacterium necrophorum, Streptococcus intermedius and Prevotella melaninogenica/histicola were associated with recurrent tonsillitis in adults, whereas species traditionally associated with acute tonsillitis like pyogenic streptococci and Staphylococcus aureus were scarce. The findings suggest that recurrent tonsillitis is a polymicrobial infection in which interactions within consortia of taxa play an etiologic role. The study contributes to the human microbiome data, to the understanding of the

  6. Molecular mapping to species level of the tonsillar crypt microbiota associated with health and recurrent tonsillitis.

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    Anders Jensen

    Full Text Available The human palatine tonsils, which belong to the central antigen handling sites of the mucosal immune system, are frequently affected by acute and recurrent infections. This study compared the microbiota of the tonsillar crypts in children and adults affected by recurrent tonsillitis with that of healthy adults and children with tonsillar hyperplasia. An in-depth 16S rRNA gene based pyrosequencing approach combined with a novel strategy that included phylogenetic analysis and detection of species-specific sequence signatures enabled identification of the major part of the microbiota to species level. A complex microbiota consisting of between 42 and 110 taxa was demonstrated in both children and adults. This included a core microbiome of 12 abundant genera found in all samples regardless of age and health status. Yet, Haemophilus influenzae, Neisseria species, and Streptococcus pneumoniae were almost exclusively detected in children. In contrast, Streptococcus pseudopneumoniae was present in all samples. Obligate anaerobes like Porphyromonas, Prevotella, and Fusobacterium were abundantly present in children, but the species diversity of Porphyromonas and Prevotella was larger in adults and included species that are considered putative pathogens in periodontal diseases, i.e. Porphyromonas gingivalis, Porphyromonas endodontalis, and Tannerella forsythia. Unifrac analysis showed that recurrent tonsillitis is associated with a shift in the microbiota of the tonsillar crypts. Fusobacterium necrophorum, Streptococcus intermedius and Prevotella melaninogenica/histicola were associated with recurrent tonsillitis in adults, whereas species traditionally associated with acute tonsillitis like pyogenic streptococci and Staphylococcus aureus were scarce. The findings suggest that recurrent tonsillitis is a polymicrobial infection in which interactions within consortia of taxa play an etiologic role. The study contributes to the human microbiome data, to the

  7. Niveles de resistencia a quinolonas y otros antimicrobianos en cepas de Escherichia coli comensales en niños de la zona periurbana de Lima, Perú Levels of quinolones resistance and other antimicrobial in non-pathogenic Escherichia coli strains in children from the periurban area of Lima, Peru

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    María J. Pons

    2012-03-01

    Full Text Available El objetivo principal del estudio fue establecer el nivel de resistencia a antimicrobianos en un total de 222 cepas comensales de E. coli de origen fecal, en Perú. Las frecuencias de resistencia encontrados, frente los antimicrobianos evaluados, fueron: ampicilina (62,6%, cotrimoxazol (48,6%, tetraciclina (43,0% y cloranfenicol (15,8%. Destacan los elevados niveles de resistencia a quinolonas: 32% al ácido nalidíxico (NAL y 12% a ciprofloxacino (CIP. Estos elevados niveles hacia las quinolonas en cepas comensales aisladas en niños de esta franja de edad, realzan el uso extendido y el impacto de consumo de este tipo de antimicrobianos en la comunidad, mostrando el riesgo potencial de su pérdida de utilidad en el área.The main aim of this study was to establish the resistance levels to antimicrobial agents, in 222 non-pathogenic E. coli strains of fecal origin in Peru. The proportion of resistance found to the evaluated antimicrobials was ampicillin (62.6%, cotrimoxazole (48,6%, tetracycline (43,0% and chloramphenicol (15,8%. We emphasize the high resistance levels found for quinolones: 32% for nalidixic acid (NAL and 12% for ciprofloxacin (CIP. These high levels of quinoloneresistance in non-pathogenic strains isolated from children in this age group highlight the extensive use and the impact of the intake of this kind of antimicrobials in the community, showing the potential risk of the loss of their utility in the area.

  8. Vigilancia de Neisseria meningitidis en Argentina, 1993-2005: distribución de serogrupos, serotipos y serosubtipos causantes de enfermedad invasiva Surveillance of Neisseria meningitidis in Argentina, 1993-2005: Distribution of serogroups, serotypes and serosubtypes isolated from invasive disease

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    L. Chiavetta

    2007-03-01

    Full Text Available Neisseria meningitidis es agente causal de enfermedades severas como meningitis, bacteriemia y síndrome de shock séptico. Se presenta la distribución en serogrupos, serotipos y serosubtipos de 2244 aislamientos de N. meningitidis obtenidos de cuadros de meningitis y/o meningococcemia durante el período 1993-2005 y analizados en el Laboratorio Nacional de Referencia del INEI-ANLIS "Dr. Carlos G. Malbrán". Estos aislamientos eran provenientes de 33 hospitales de todo el país, conformados en una red nacional de laboratorios para el estudio de meningitis bacteriana. Durante el período 1993-1995 prevaleció el serogrupo B (66%, mientras que entre los años 1995 y 2001 prevaleció el serogrupo C (65%; a partir de esta fecha se restableció la prevalencia de B. En los últimos 5 años los serogrupos Y y W135 representaron en su conjunto el 15,6%, mientras que hasta el año 2000 no superaron el 4,7%. Se registró mayor diversidad en la distribución de serotipos y serosubtipos dentro del serogrupo B que dentro del serogrupo C. Los aislamientos no subtipables durante todo el período de estudio representaron el 52,8%; este elevado porcentaje evidencia la limitada capacidad de la serología para la determinación de subtipos de meningococo.Neisseria meningitidis is an important cause of meningitis, bacteremia and septic shock syndrome. We herein present the distribution of serogroups, serotypes and serosubtypes of 2244 isolates of N. meningitidis from patients with meningitis or meningococcemia, received within the period 1993-2005, in the National Reference Laboratory, INEI-ANLIS "Dr. Carlos G. Malbrán", from 33 Argentine hospitals that are included in a National Network devoted to for the study of bacterial meningitis. Between 1993-1995, serogroup B was prevalent (66% whereas in the period from 1995-2001, serogroup C prevailed (65%. However, following but after that period, the prevalence of serogroup B was recovered. In the last 5 years of the

  9. Silica desiccant packets for storage and transport of Streptococcus pneumoniae and other clinically relevant species.

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    Casey L Pell

    Full Text Available Bacterial isolates are often transported between laboratories for research and diagnostic purposes. Silica desiccant packets (SDPs, which are inexpensive and do not require freezing, were evaluated for storage and recovery of bacterial isolates. Conditions such as inoculum size, swab type and temperature of storage were investigated using ten Streptococcus pneumoniae isolates. The optimized protocol was then tested using 49 additional S. pneumoniae isolates representing 40 serogroups. Overall, S. pneumoniae growth was considered satisfactory (>100 colony forming units for 98/109 (89.9% and 20/20 (100% swabs after 14 days at room temperature or 28 days at 4° C, respectively. Storage in SDPs did not impact on the ability of S. pneumoniae isolates to be subsequently serotyped. When the survival of nine other clinically relevant bacterial species was tested, seven were viable after 28 days at room temperature, the exceptions being Neisseria gonorrhoeae and Haemophilus influenzae. SDPs are suitable for transport and short-term storage of bacterial species including S. pneumoniae.

  10. Agroforestry Species Switchboard

    DEFF Research Database (Denmark)

    Kindt, R.; John, I.; Ordonez, J.

    2016-01-01

    The current version of the Agroforestry Species Switchboard documents the presence of a total of 26,135 plant species (33,813 species including synonyms) across 19 web-based databases. When available, hyperlinks to information on the selected species in particular databases are provided. In total...

  11. Isolation and molecular characterization of Cryptococcus species isolated from pigeon nests and Eucalyptus trees.

    Science.gov (United States)

    Kamari, A; Sepahvand, A; Mohammadi, R

    2017-06-01

    Cryptococcus species are pathogenic and non-pathogenic basidiomycete yeasts that are found widely in the environment. Based on phenotypic methods, this genus has many species; however, its taxonomy is presently being re-evaluated by modern techniques. The Cryptococcus species complex includes two sibling taxa of Cryptococcus neoformans and Cryptococcus gattii . We aimed to investigate the possible distribution of Cryptococcus species in pigeon nests and Eucalyptus trees in Ilam, Iran, using molecular techniques. Two hundred and seventy-four specimens were collected from pigeon nests and Eucalyptus trees during 2016-2017. All the specimens were sub-cultured on Sabouraud Glucose Agar with chloramphenicol and bird seed agar. For molecular identification, the ITS15.8SITS2 rDNA region was amplified using the first and fourth internal transcribed spacer (ITS1 and ITS4, respectively) primers. The purified products were applied for cycle sequencing reactions in forward direction with ITS1 primer. The obtained results were analyzed with Chromas 2.3. Thirty-three out of 186 cultures (17.7%) and 11 out of 88 cultures (12.5%) were positive among pigeon nest and Eucalyptus tree specimens, respectively. Cryptococcus albidus (17.2%), C. albidus var. kuetzingii (3.4%), C. adeliensis (3.4%), C. uzbekistanensis (3.4%), and C. neoformans var. grubii (3.4%) were isolated from pigeon nests, and Cryptococcus adeliensis (25%) was the only Cryptococcus species isolated from Eucalyptus trees. The presence of pigeons and Eucalyptus trees in the vicinity of some particular places such as rest homes and hospitals should be considered as a risk factor for the immunocompromised population.

  12. Purificación de lipopolisacárido de Neisseria meningitidis a partir de una fracción colateral del proceso de producción de VA-MENGOC-BC®

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    Julio A. Balboa

    2008-04-01

    Full Text Available El trabajo tuvo como objetivo purificar lipopolisacáridos (LPS de Neisseria meningitidis a partir de una fracción colateral del proceso de producción de la vacuna antimeningocócica VA-MENGOC-BC®, el sobrenadante que se obtiene del paso de ultracentrifugación durante el proceso de extracción de las proteínas de membrana externa del meningococo. La purificación se realizó mediante precipitación con etanol al 80%, extracción de las proteínas con fenol al 90% entre 65-70 ºC y ultracentrifugación fraccionada a 105,000 g. Se obtuvieron tres lotes de LPS, en total 1,069 g, con un contenido de proteínas, ácidos nucleicos y ácido sálico respecto al LPS de 0,5%, 0,3% y 2,2% (m/m respectivamente. La evaluación por cromatografía mostró una alta integridad molecular, con valores de constante de distribución reproducibles (0,36-0,38 y una posible asociación del ácido siálico al LPS. Se apreció homogeneidad en el perfil electroforético de los tres lotes y alta actividad endotóxica. El LPS purificado fue identificado fundamentalmente como del inmunotipo L3,7,9. El procedimiento de purificación empleado permite aprovechar una fracción colateral del proceso de producción de la vacuna, es escalable, no incluye métodos cromatográficos, y posibilita la obtención de gran cantidad de LPS de Neisseria meningitidis, no disponible en el mercado, con elevada pureza y alta actividad endotóxica.

  13. A cross-sectional study assessing the pharyngeal carriage of Neisseria meningitidis in subjects aged 1-24 years in the city of Embu das Artes, São Paulo, Brazil.

    Science.gov (United States)

    Weckx, Lily Yin; Puccini, Rosana Fiorini; Machado, Antónia; Gonçalves, Maria Gisele; Tuboi, Suely; de Barros, Eliana; Devadiga, Raghavendra; Ortega-Barria, Eduardo; Colindres, Romulo

    Meningococcal carriage is a prerequisite for invasive infection. This cross-sectional study assessed the pharyngeal carriage prevalence in healthy subjects aged 1-24 years in Embu das Artes city, São Paulo, Brazil. Pharyngeal swabs were examined for the presence of Neisseria meningitidis. The isolates were tested for different serogroups using agglutination and polymerase chain reaction. A logistic regression model assessed any independent association between Neisseria meningitidis carriage and various risk factors. A total of 87/967 subjects (9%, 95% Confidence Interval (CI): 7.3-11.0) tested positive for N. meningitidis: 6.2% (95% CI: 3.8-9.4) in 1-4 years, 8.5% (95% CI: 5.1-13.0) in 5-9 years, 12.5% (95% CI: 7.8-18.6) in 10-14 years, 12.6% (95% CI: 7.4-19.7) in 15-19 years and 9% (95% CI: 4.9-14.9) in 20-24 years age groups. Highest carriage prevalence was observed in adolescents 10-19 years old. Serogroup C was predominant (18.4%) followed by serogroup B (12.6%). The 15-19 years age group showed a significant association between number of household members and carriers of N. meningitidis. This cross-sectional study is the first in Brazil to evaluate meningococcal carriage prevalence and associated factors in a wide age range. Copyright © 2017 Sociedade Brasileira de Infectologia. Published by Elsevier Editora Ltda. All rights reserved.

  14. Beyond Streptococcus mutans: Dental Caries Onset Linked to Multiple Species by 16S rRNA Community Analysis

    Science.gov (United States)

    Gross, Erin L.; Beall, Clifford J.; Kutsch, Stacey R.; Firestone, Noah D.; Leys, Eugene J.; Griffen, Ann L.

    2012-01-01

    Dental caries in very young children may be severe, result in serious infection, and require general anesthesia for treatment. Dental caries results from a shift within the biofilm community specific to the tooth surface, and acidogenic species are responsible for caries. Streptococcus mutans, the most common acid producer in caries, is not always present and occurs as part of a complex microbial community. Understanding the degree to which multiple acidogenic species provide functional redundancy and resilience to caries-associated communities will be important for developing biologic interventions. In addition, microbial community interactions in health and caries pathogenesis are not well understood. The purpose of this study was to investigate bacterial community profiles associated with the onset of caries in the primary dentition. In a combination cross-sectional and longitudinal design, bacterial community profiles at progressive stages of caries and over time were examined and compared to those of health. 16S rRNA gene sequencing was used for bacterial community analysis. Streptococcus mutans was the dominant species in many, but not all, subjects with caries. Elevated levels of S. salivarius, S. sobrinus, and S. parasanguinis were also associated with caries, especially in subjects with no or low levels of S. mutans, suggesting these species are alternative pathogens, and that multiple species may need to be targeted for interventions. Veillonella, which metabolizes lactate, was associated with caries and was highly correlated with total acid producing species. Among children without previous history of caries, Veillonella, but not S. mutans or other acid-producing species, predicted future caries. Bacterial community diversity was reduced in caries as compared to health, as many species appeared to occur at lower levels or be lost as caries advanced, including the Streptococcus mitis group, Neisseria, and Streptococcus sanguinis. This may have

  15. Endangered Species Act

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The purpose of the Endangered Species Act (ESA) is to protect and recover imperiled species and the ecosystems upon which they depend. The U.S. Fish and Wildlife...

  16. Endangered Species Protection Bulletins

    Science.gov (United States)

    Endangered Species Protection Bulletins set forth geographically specific pesticide use limitations for the protection of threatened and endangered (listed) species and their designated critical habitat. Find out how to get and use Bulletins.

  17. Functions and origin of plasmids in Erwinia species that are pathogenic to or epiphytically associated with pome fruit trees.

    Science.gov (United States)

    Llop, Pablo; Barbé, Silvia; López, María M

    The genus Erwinia includes plant-associated pathogenic and non-pathogenic species. Among them, all species pathogenic to pome fruit trees ( E. amylovora, E. pyrifoliae, E. piriflorinigrans, Erwinia sp. from Japan) cause similar symptoms, but differ in their degrees of aggressiveness, i.e. in symptoms, host range or both. The presence of plasmids of similar size, in the range of 30 kb, is a common characteristic that they possess. Besides, they share some genetic content with high homology in several genes associated with exopolysaccharide production and hence, with virulence, as well as in some other genes. Knowledge of the content of these plasmids and comparative genetic analyses may provide interesting new clues to understanding the origin and evolution of these pathogens and the level of symptoms they produce. Furthermore, genetic similarities observed among some of the plasmids (and genomes) from the above indicated pathogenic species and E. tasmaniensis or E. billingiae , which are epiphytic on the same hosts, may reveal associations that could expose the mechanisms of origin of pathogens. A summary of the current information on their plasmids and the relationships among them is presented here.

  18. Species diversity modulates predation

    NARCIS (Netherlands)

    Kratina, P.; Vos, M.; Anholt, B.R.

    2007-01-01

    Predation occurs in a context defined by both prey and non-prey species. At present it is largely unknown how species diversity in general, and species that are not included in a predator's diet in particular, modify predator–prey interactions.Therefore we studied how both the density and diversity

  19. Bacterial Communities of Diverse Drosophila Species: Ecological Context of a Host–Microbe Model System

    Science.gov (United States)

    Bhatnagar, Srijak; Eisen, Jonathan A.; Kopp, Artyom

    2011-01-01

    Drosophila melanogaster is emerging as an important model of non-pathogenic host–microbe interactions. The genetic and experimental tractability of Drosophila has led to significant gains in our understanding of animal–microbial symbiosis. However, the full implications of these results cannot be appreciated without the knowledge of the microbial communities associated with natural Drosophila populations. In particular, it is not clear whether laboratory cultures can serve as an accurate model of host–microbe interactions that occur in the wild, or those that have occurred over evolutionary time. To fill this gap, we characterized natural bacterial communities associated with 14 species of Drosophila and related genera collected from distant geographic locations. To represent the ecological diversity of Drosophilids, examined species included fruit-, flower-, mushroom-, and cactus-feeders. In parallel, wild host populations were compared to laboratory strains, and controlled experiments were performed to assess the importance of host species and diet in shaping bacterial microbiome composition. We find that Drosophilid flies have taxonomically restricted bacterial communities, with 85% of the natural bacterial microbiome composed of only four bacterial families. The dominant bacterial taxa are widespread and found in many different host species despite the taxonomic, ecological, and geographic diversity of their hosts. Both natural surveys and laboratory experiments indicate that host diet plays a major role in shaping the Drosophila bacterial microbiome. Despite this, the internal bacterial microbiome represents only a highly reduced subset of the external bacterial communities, suggesting that the host exercises some level of control over the bacteria that inhabit its digestive tract. Finally, we show that laboratory strains provide only a limited model of natural host–microbe interactions. Bacterial taxa used in experimental studies are rare or absent in

  20. Species choice, provenance and species trials among native Brazilian species

    Energy Technology Data Exchange (ETDEWEB)

    Drumond, M A

    1982-01-01

    Six papers from the conference are presented. Drumond, M.A., Potential of species native to the semi-arid tropics, 766-781, (Refs. 18), reports on Anadenanthera macrocarpa, Mimosa species, Schinopsis brasiliensis, Spondias tuberosa, Ziziphus joazeiro, Cnidoscolus phyllacanthus, Bursera leptophleos (leptophloeos), Tabebuia impetiginosa, Astronium urundeuva, and Mimosa caesalpinia. Monteiro, R.F.R., Speltz, R.M., Gurgel, J.T. do A.; Silvicultural performance of 24 provenances of Araucaria angustifolia in Parana, 814-824, (Refs. 8). Pires, C.L. da S., Kalil Filho, A.N., Rosa, P.R.F. da, Parente, P.R., Zanatto, A.C.S.; Provenance trials of Cordia alliodora in the State of Sao Paulo, 988-995, (Refs. 9). Nogueira, J.C.B., Siqueira, A.C.M.F., Garrido, M.A.O., Gurgel Garrido, L.M. do A., Rosa, P.R.F., Moraes, J.L. de, Zandarin, M.A., Gurgel Filho, O.A., Trials of some native species in various regions of the State of Sao Paulo, 1051-1063, (Refs. 9) describes Centrolobium tomentosum, Peltophorum dubium, Tabebuia vellosoi, Cariniana legalis, and Balfourodendron riedelianum. Batista, M.P., Borges, J.F., Franco, M.A.B.; Early growth of a native species in comparison with exotics in northeastern Para, Brazil, 1105-1110, (Refs. 3). Jacaranda copaia is compared with Gmelina arborea, Pinus caribaea various hondurensis, Eucalyptus deglupta, and E. urophylla. Lima, P.C.F., Souza, S.M. de, Drumond, M.A.; Trials of native forest species at Petrolina, Pernambuco, 1139-1148, (Refs. 8), deals with Anadenanthera macrocarpa, Piptadenia obliqua, Pithecellobium foliolosum, Astronium urundeuva, Schinopsis brasiliensis, Cassia excelsa, Caesalpinia pyramidalis, Parkia platycephala, Pseudobombax simplicifolium, Tabebuia impetiginosa, Caesalpinia ferrea, and Aspidosperma pyrifolium. 18 references.

  1. Separation of chemical species

    International Nuclear Information System (INIS)

    Rentzepis, P.M.

    1977-01-01

    Isotopic separation is accomplished by (1) a second photon irradiation step for selective ionization of a first isotopic species and (2) selecti