A review of Chlamydia pneumoniae and atherosclerosis

DEFF Research Database (Denmark)

Lindholt, Jes Sanddal; Fasting, H; Henneberg, E W

1999-01-01

Chlamydia pneumoniae is a Gram-negative obligate intracellular bacterium that causes acute upper and lower respiratory infections. Its distribution is worldwide. Seroepidemiological studies have shown an association between C. pneumoniae and atherosclerosis, and the risk of acute myocardial...

PKC-η-MARCKS Signaling Promotes Intracellular Survival of Unopsonized Burkholderia thailandensis.

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Micheva-Viteva, Sofiya N; Shou, Yulin; Ganguly, Kumkum; Wu, Terry H; Hong-Geller, Elizabeth

2017-01-01

Pathogenic Burkholderia rely on host factors for efficient intracellular replication and are highly refractory to antibiotic treatment. To identify host genes that are required by Burkholderia spp. during infection, we performed a RNA interference (RNAi) screen of the human kinome and identified 35 host kinases that facilitated Burkholderia thailandensis intracellular survival in human monocytic THP-1 cells. We validated a selection of host kinases using imaging flow cytometry to assess efficiency of B. thailandensis survival in the host upon siRNA-mediated knockdown. We focused on the role of the novel protein kinase C isoform, PKC-η, in Burkholderia infection and characterized PKC-η/MARCKS signaling as a key event that promotes the survival of unopsonized B. thailandensis CDC2721121 within host cells. While infection of lung epithelial cells with unopsonized Gram-negative bacteria stimulated phosphorylation of Ser175/160 in the MARCKS effector domain, siRNA-mediated knockdown of PKC-η expression reduced the levels of phosphorylated MARCKS by >3-fold in response to infection with Bt CDC2721121. We compared the effect of the conventional PKC-α and novel PKC-η isoforms on the growth of B. thailandensis CDC2721121 within monocytic THP-1 cells and found that ≥75% knock-down of PRKCH transcript levels reduced intracellular bacterial load 100% more efficiently when compared to growth in cells siRNA-depleted of the classical PKC-α, suggesting that the PKC-η isoform can specifically mediate Burkholderia intracellular survival. Based on imaging studies of intracellular B. thailandensis , we found that PKC-η function stimulates phagocytic pathways that promote B. thailandensis escape into the cytoplasm leading to activation of autophagosome flux. Identification of host kinases that are targeted by Burkholderia during infection provides valuable molecular insights in understanding Burkholderia pathogenesis, and ultimately, in designing effective host

DXD Motif-Dependent and -Independent Effects of the Chlamydia trachomatis Cytotoxin CT166

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Miriam Bothe

2015-02-01

Full Text Available The Gram-negative, intracellular bacterium Chlamydia trachomatis causes acute and chronic urogenital tract infection, potentially leading to infertility and ectopic pregnancy. The only partially characterized cytotoxin CT166 of serovar D exhibits a DXD motif, which is important for the enzymatic activity of many bacterial and mammalian type A glycosyltransferases, leading to the hypothesis that CT166 possess glycosyltransferase activity. CT166-expressing HeLa cells exhibit actin reorganization, including cell rounding, which has been attributed to the inhibition of the Rho-GTPases Rac/Cdc42. Exploiting the glycosylation-sensitive Ras(27H5 antibody, we here show that CT166 induces an epitope change in Ras, resulting in inhibited ERK and PI3K signaling and delayed cell cycle progression. Consistent with the hypothesis that these effects strictly depend on the DXD motif, CT166 with the mutated DXD motif causes neither Ras-ERK inhibition nor delayed cell cycle progression. In contrast, CT166 with the mutated DXD motif is still capable of inhibiting cell migration, suggesting that CT166 with the mutated DXD motif cannot be regarded as inactive in any case. Taken together, CT166 affects various fundamental cellular processes, strongly suggesting its importance for the intracellular survival of chlamydia.

Chlamydia pneumoniae : studies on an emerging pathogen

NARCIS (Netherlands)

R.P.A.J. Verkooyen (Roel)

1997-01-01

textabstractThe Chlamydiae are characterized as bacteria because of the composition of their cell wall and their growth by binary division. However, they are obligate intracellular bacterial parasites of eukaryotic cells that have a unique replication cycle similar to Rickettsia. Chlamydial

Multi locus sequence typing of Chlamydiales: clonal groupings within the obligate intracellular bacteria Chlamydia trachomatis

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Langerak Ankie A

2008-02-01

Full Text Available Abstract Background The obligate intracellular growing bacterium Chlamydia trachomatis causes diseases like trachoma, urogenital infection and lymphogranuloma venereum with severe morbidity. Several serovars and genotypes have been identified, but these could not be linked to clinical disease or outcome. The related Chlamydophila pneumoniae, of which no subtypes are recognized, causes respiratory infections worldwide. We developed a multi locus sequence typing (MLST scheme to understand the population genetic structure and diversity of these species and to evaluate the association between genotype and disease. Results A collection of 26 strains of C. trachomatis of different serovars and clinical presentation and 18 strains of C. pneumoniae were included in the study. For comparison, sequences of C. abortus, C. psittaci, C. caviae, C. felis, C. pecorum (Chlamydophila, C. muridarum (Chlamydia and of Candidatus protochlamydia and Simkania negevensis were also included. Sequences of fragments (400 – 500 base pairs from seven housekeeping genes (enoA, fumC, gatA, gidA, hemN, hlfX, oppA were analysed. Analysis of allelic profiles by eBurst revealed three non-overlapping clonal complexes among the C. trachomatis strains, while the C. pneumoniae strains formed a single group. An UPGMA tree produced from the allelic profiles resulted in three groups of sequence types. The LGV strains grouped in a single cluster, while the urogenital strains were distributed over two separated groups, one consisted solely of strains with frequent occurring serovars (E, D and F. The distribution of the different serovars over the three groups was not consistent, suggesting exchange of serovar encoding ompA sequences. In one instance, exchange of fumC sequences between strains of different groups was observed. Cluster analyses of concatenated sequences of the Chlamydophila and Chlamydia species together with those of Candidatus Protochlamydia amoebophila and Simkania

Multi locus sequence typing of Chlamydiales: clonal groupings within the obligate intracellular bacteria Chlamydia trachomatis.

Science.gov (United States)

Pannekoek, Yvonne; Morelli, Giovanna; Kusecek, Barica; Morré, Servaas A; Ossewaarde, Jacobus M; Langerak, Ankie A; van der Ende, Arie

2008-02-28

The obligate intracellular growing bacterium Chlamydia trachomatis causes diseases like trachoma, urogenital infection and lymphogranuloma venereum with severe morbidity. Several serovars and genotypes have been identified, but these could not be linked to clinical disease or outcome. The related Chlamydophila pneumoniae, of which no subtypes are recognized, causes respiratory infections worldwide. We developed a multi locus sequence typing (MLST) scheme to understand the population genetic structure and diversity of these species and to evaluate the association between genotype and disease. A collection of 26 strains of C. trachomatis of different serovars and clinical presentation and 18 strains of C. pneumoniae were included in the study. For comparison, sequences of C. abortus, C. psittaci, C. caviae, C. felis, C. pecorum (Chlamydophila), C. muridarum (Chlamydia) and of Candidatus protochlamydia and Simkania negevensis were also included. Sequences of fragments (400 - 500 base pairs) from seven housekeeping genes (enoA, fumC, gatA, gidA, hemN, hlfX, oppA) were analysed. Analysis of allelic profiles by eBurst revealed three non-overlapping clonal complexes among the C. trachomatis strains, while the C. pneumoniae strains formed a single group. An UPGMA tree produced from the allelic profiles resulted in three groups of sequence types. The LGV strains grouped in a single cluster, while the urogenital strains were distributed over two separated groups, one consisted solely of strains with frequent occurring serovars (E, D and F). The distribution of the different serovars over the three groups was not consistent, suggesting exchange of serovar encoding ompA sequences. In one instance, exchange of fumC sequences between strains of different groups was observed. Cluster analyses of concatenated sequences of the Chlamydophila and Chlamydia species together with those of Candidatus Protochlamydia amoebophila and Simkania negevensis resulted in a tree identical to that

Chlamydia infection across host species boundaries promotes distinct sets of transcribed anti-apoptotic factors.

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Joshua eMessinger

2015-12-01

Full Text Available Chlamydiae, obligate intracellular bacteria, cause significant human and veterinary associated diseases. Having emerged an estimated 700-million years ago, these bacteria have twice adapted to humans as a host species, causing sexually transmitted infection (C. trachomatis and respiratory associated disease (C. pneumoniae. The principle mechanism of host cell defense against these intracellular bacteria is the induction of cell death via apoptosis. However, in the arms race of co-evolution, Chlamydiae have developed mechanisms to promote cell viability and inhibit cell death. Herein we examine the impact of Chlamydiae infection across multiple host species on transcription of anti-apoptotic genes. We found mostly distinct patterns of gene expression (Mcl1 and cIAPs elicited by each pathogen-host pair indicating Chlamydiae infection across host species boundaries does not induce a universally shared host response. Understanding species specific host-pathogen interactions is paramount to deciphering how potential pathogens become emerging diseases.

Functional and Biochemical Analysis of Chlamydia trachomatis MurC, an Enzyme Displaying UDP-N-Acetylmuramate:Amino Acid Ligase Activity

OpenAIRE

Hesse, Lars; Bostock, Julieanne; Dementin, Sebastien; Blanot, Didier; Mengin-Lecreulx, Dominique; Chopra, Ian

2003-01-01

Chlamydiae are unusual obligate intracellular bacteria that cause serious infections in humans. Chlamydiae contain genes that appear to encode products with peptidoglycan biosynthetic activity. The organisms are also susceptible to antibiotics that inhibit peptidoglycan synthesis. However, chlamydiae do not synthesize detectable peptidoglycan. The paradox created by these observations is known as the chlamydial anomaly. The MurC enzyme of chlamydiae, which is synthesized as a bifunctional Mur...

[FEMALE STEROID HORMONES - MODULATORS OF IMMUNE RESPONSE TO GENITAL CHLAMYDIA TRACHOMATIS INFECTION.

Science.gov (United States)

Kovachev, E; Ivanov, S; Bechev, B; Angelova, M; Grueva, E; Kolev, N; Ivanova, V

In the recent years according to WHO, genital chlamydia is the mos't common sexually transmitted infection. Chlamydia Trachomatis is an intracellular parasite which target are the tubular epithelial cells of the urethra, endocervix, endometrium, endosalpinx, conjunctiva, synovial lining of the joints, Glisson's capsule of the liver Our study, as well as some international researches, shows that in the cases of genital chlamydia there are changes in the ovarian hormones (estradiol and progesterone), their impact on the immune system and their importance for the development and the complications of the infection with Chlamydia trachomatis. The physiological level of the steroid hormones in its turn contributes for the normalization of the local immunity and reduces the possibility of recurrences.

Multi locus sequence typing of Chlamydia reveals an association between Chlamydia psittaci genotypes and host species.

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Pannekoek, Yvonne; Dickx, Veerle; Beeckman, Delphine S A; Jolley, Keith A; Keijzers, Wendy C; Vretou, Evangelia; Maiden, Martin C J; Vanrompay, Daisy; van der Ende, Arie

2010-12-02

Chlamydia comprises a group of obligate intracellular bacterial parasites responsible for a variety of diseases in humans and animals, including several zoonoses. Chlamydia trachomatis causes diseases such as trachoma, urogenital infection and lymphogranuloma venereum with severe morbidity. Chlamydia pneumoniae is a common cause of community-acquired respiratory tract infections. Chlamydia psittaci, causing zoonotic pneumonia in humans, is usually hosted by birds, while Chlamydia abortus, causing abortion and fetal death in mammals, including humans, is mainly hosted by goats and sheep. We used multi-locus sequence typing to asses the population structure of Chlamydia. In total, 132 Chlamydia isolates were analyzed, including 60 C. trachomatis, 18 C. pneumoniae, 16 C. abortus, 34 C. psittaci and one of each of C. pecorum, C. caviae, C. muridarum and C. felis. Cluster analyses utilizing the Neighbour-Joining algorithm with the maximum composite likelihood model of concatenated sequences of 7 housekeeping fragments showed that C. psittaci 84/2334 isolated from a parrot grouped together with the C. abortus isolates from goats and sheep. Cluster analyses of the individual alleles showed that in all instances C. psittaci 84/2334 formed one group with C. abortus. Moving 84/2334 from the C. psittaci group to the C. abortus group resulted in a significant increase in the number of fixed differences and elimination of the number of shared mutations between C. psittaci and C. abortus. C. psittaci M56 from a muskrat branched separately from the main group of C. psittaci isolates. C. psittaci genotypes appeared to be associated with host species. The phylogenetic tree of C. psittaci did not follow that of its host bird species, suggesting host species jumps. In conclusion, we report for the first time an association between C. psittaci genotypes with host species.

Multi locus sequence typing of Chlamydia reveals an association between Chlamydia psittaci genotypes and host species.

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Yvonne Pannekoek

2010-12-01

Full Text Available Chlamydia comprises a group of obligate intracellular bacterial parasites responsible for a variety of diseases in humans and animals, including several zoonoses. Chlamydia trachomatis causes diseases such as trachoma, urogenital infection and lymphogranuloma venereum with severe morbidity. Chlamydia pneumoniae is a common cause of community-acquired respiratory tract infections. Chlamydia psittaci, causing zoonotic pneumonia in humans, is usually hosted by birds, while Chlamydia abortus, causing abortion and fetal death in mammals, including humans, is mainly hosted by goats and sheep. We used multi-locus sequence typing to asses the population structure of Chlamydia. In total, 132 Chlamydia isolates were analyzed, including 60 C. trachomatis, 18 C. pneumoniae, 16 C. abortus, 34 C. psittaci and one of each of C. pecorum, C. caviae, C. muridarum and C. felis. Cluster analyses utilizing the Neighbour-Joining algorithm with the maximum composite likelihood model of concatenated sequences of 7 housekeeping fragments showed that C. psittaci 84/2334 isolated from a parrot grouped together with the C. abortus isolates from goats and sheep. Cluster analyses of the individual alleles showed that in all instances C. psittaci 84/2334 formed one group with C. abortus. Moving 84/2334 from the C. psittaci group to the C. abortus group resulted in a significant increase in the number of fixed differences and elimination of the number of shared mutations between C. psittaci and C. abortus. C. psittaci M56 from a muskrat branched separately from the main group of C. psittaci isolates. C. psittaci genotypes appeared to be associated with host species. The phylogenetic tree of C. psittaci did not follow that of its host bird species, suggesting host species jumps. In conclusion, we report for the first time an association between C. psittaci genotypes with host species.

Proteolytic cleavage of the Chlamydia pneumoniae major outer membrane protein in the absence of Pmp10

DEFF Research Database (Denmark)

Juul, Nicolai Stefan; Timmerman, E; Gevaert, K

2007-01-01

The genome of the obligate intracellular bacteria Chlamydia pneumoniae contains 21 genes encoding polymorphic membrane proteins (Pmp). While no function has yet been attributed to the Pmps, they may be involved in an antigenic variation of the Chlamydia surface. It has previously been demonstrated...

Survival of chlamydiae in human semen prepared for artificial insemination by donor

DEFF Research Database (Denmark)

Thorsen, Poul; Møller, Birger R.; Halkier-Sørensen, Lars

1991-01-01

Semen specimens from 21 men with urethral infection with Chlamydia trachomatis were tested for the presence of the organism before and after cryopreservation for 3 weeks of storage at -196 degrees C. Five specimens were chlamydia-positive before preservation and four of them were still positive...... after storage when examined by enzyme immunoassay (Chlamydiazyme). When examined by cell culture, four proved chlamydia- positive before storage and two afterwards. The results indicate that testing for C. trachomatis has to be performed from the urethra of all donors of semen used for artificial...

Chlamydia co-opts the rod shape-determining proteins MreB and Pbp2 for cell division.

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Ouellette, Scot P; Karimova, Gouzel; Subtil, Agathe; Ladant, Daniel

2012-07-01

Chlamydiae are obligate intracellular bacterial pathogens that have extensively reduced their genome in adapting to the intracellular environment. The chlamydial genome contains only three annotated cell division genes and lacks ftsZ. How this obligate intracellular pathogen divides is uncharacterized. Chlamydiae contain two high-molecular-weight (HMW) penicillin binding proteins (Pbp) implicated in peptidoglycan synthesis, Pbp2 and Pbp3/FtsI. We show here, using HMW Pbp-specific penicillin derivatives, that both Pbp2 and Pbp3 are essential for chlamydial cell division. Ultrastructural analyses of antibiotic-treated cultures revealed distinct phenotypes: Pbp2 inhibition induced internal cell bodies within a single outer membrane whereas Pbp3 inhibition induced elongated phenotypes with little internal division. Each HMW Pbp interacts with the Chlamydia cell division protein FtsK. Chlamydiae are coccoid yet contain MreB, a rod shape-determining protein linked to Pbp2 in bacilli. Using MreB-specific antibiotics, we show that MreB is essential for chlamydial growth and division. Importantly, co-treatment with MreB-specific and Pbp-specific antibiotics resulted in the MreB-inhibited phenotype, placing MreB upstream of Pbp function in chlamydial cell division. Finally, we showed that MreB also interacts with FtsK. We propose that, in Chlamydia, MreB acts as a central co-ordinator at the division site to substitute for the lack of FtsZ in this bacterium. © 2012 Blackwell Publishing Ltd.

Whole-Genome Sequence of Chlamydia abortus Strain GN6 Isolated from Aborted Yak Fetus

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Li, Zhaocai; Cai, Jinshan; Cao, Xiaoan; Lou, Zhongzi; Chao, Yilin; Kan, Wei; Zhou, Jizhang

2017-01-01

ABSTRACT The obligate intracellular Gram-negative bacterium Chlamydia abortus is one of the causative agents of abortion and fetal loss in sheep, goats, and cattle in many countries. It also affects the reproductivity of yaks (Bos grunniens). This study reports the whole-genome sequence of Chlamydia abortus strain GN6, which was isolated from aborted yak fetus in Qinghai-Tibetan Plateau, China.

Seroprevalence and Risk Factors of Chlamydia Infection in Domestic Rabbits (Oryctolagus cuniculus in China

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Xiaoting Ni

2015-01-01

Full Text Available Chlamydia spp. are obligate intracellular bacteria distributed all over the world, known to cause various forms of diseases in animals and humans. In the present study, a serological survey was conducted to detect the seroprevalence and risk factors associated with rabbit chlamydiosis in northeast China, including Liaoning province, Jilin province, Heilongjiang province, and Inner Mongolia Autonomous Region. Antibodies to Chlamydia were determined by indirect hemagglutination assay (IHA. The overall seroprevalence was estimated at 17.88% in total of 800 blood samples. The Chlamydia seroprevalence varied in domestic rabbits from different factors, and genders of domestic rabbits were considered as major risk factors associated with Chlamydia infection. Our study revealed a widespread and high prevalence of Chlamydia infection in domestic rabbits in northeast China, with higher exposure risk in female domestic rabbits. These findings suggested the potential importance of domestic rabbits in the transmission of zoonotic Chlamydia infection, and thus Chlamydia should be taken into consideration in diagnosing rabbit diseases. To our knowledge, there is no report of Chlamydia infection in domestic rabbits in China and the results extend the host range for Chlamydia, which has important implications for public health and the local economy.

Whole-Genome Sequence of Chlamydia abortus Strain GN6 Isolated from Aborted Yak Fetus.

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Li, Zhaocai; Cai, Jinshan; Cao, Xiaoan; Lou, Zhongzi; Chao, Yilin; Kan, Wei; Zhou, Jizhang

2017-08-31

The obligate intracellular Gram-negative bacterium Chlamydia abortus is one of the causative agents of abortion and fetal loss in sheep, goats, and cattle in many countries. It also affects the reproductivity of yaks ( Bos grunniens ). This study reports the whole-genome sequence of Chlamydia abortus strain GN6, which was isolated from aborted yak fetus in Qinghai-Tibetan Plateau, China. Copyright © 2017 Li et al.

Severe Tryptophan Starvation Blocks Onset of Conventional Persistence and Reduces Reactivation of Chlamydia trachomatis▿

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Leonhardt, Ralf M.; Lee, Seung-Joon; Kavathas, Paula B.; Cresswell, Peter

2007-01-01

The intracellular survival of the bacterial pathogen Chlamydia trachomatis depends on protein synthesis by the microbe soon after internalization. Pharmacologic inhibition of bacterial translation inhibits early trafficking of the parasitophorous vacuole (inclusion) to the microtubule-organizing center (MTOC) and promotes its fusion with lysosomes, which is normally blocked by Chlamydia. Depletion of cellular tryptophan pools by gamma interferon-inducible indoleamine-2,3-dioxygenase (IDO) is believed to be the major innate immune mechanism controlling C. trachomatis infection in human cells, an action to which the bacteria can respond by converting into a nonreplicating but highly reactivatable persistent state. However, whether severe IDO-mediated tryptophan starvation can be sufficient to fully arrest the chlamydial life cycle and thereby counteract the onset of persistence is unknown. Here we demonstrate that at low exogenous tryptophan concentrations a substantial fraction of C. trachomatis bacteria fail to traffic to the MTOC or to switch into the conventional persistent state in gamma interferon-induced human cells. The organisms stay scattered in the cell periphery, do not retain infectivity, and display only low transcriptional activity. Importantly, the rate at which these aberrant Chlamydia bacteria become reactivated upon replenishment of cellular tryptophan pools is substantially lower. Thus, severe tryptophan depletion in cells with high IDO activity affects chlamydial development more rigorously than previously described. PMID:17724071

Ironing Out the Unconventional Mechanisms of Iron Acquisition and Gene Regulation in Chlamydia

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Nick D. Pokorzynski

2017-09-01

Full Text Available The obligate intracellular pathogen Chlamydia trachomatis, along with its close species relatives, is known to be strictly dependent upon the availability of iron. Deprivation of iron in vitro induces an aberrant morphological phenotype termed “persistence.” This persistent phenotype develops in response to various immunological and nutritional insults and may contribute to the development of sub-acute Chlamydia-associated chronic diseases in susceptible populations. Given the importance of iron to Chlamydia, relatively little is understood about its acquisition and its role in gene regulation in comparison to other iron-dependent bacteria. Analysis of the genome sequences of a variety of chlamydial species hinted at the involvement of unconventional mechanisms, being that Chlamydia lack many conventional systems of iron homeostasis that are highly conserved in other bacteria. Herein we detail past and current research regarding chlamydial iron biology in an attempt to provide context to the rapid progress of the field in recent years. We aim to highlight recent discoveries and innovations that illuminate the strategies involved in chlamydial iron homeostasis, including the vesicular mode of acquiring iron from the intracellular environment, and the identification of a putative iron-dependent transcriptional regulator that is synthesized as a fusion with a ABC-type transporter subunit. These recent findings, along with the noted absence of iron-related homologs, indicate that Chlamydia have evolved atypical approaches to the problem of iron homeostasis, reinvigorating research into the iron biology of this pathogen.

Antigenic specificity and morphologic characteristics of Chlamydia trachomatis, strain SFPD, isolated from hamsters with proliferative ileitis.

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Fox, J G; Stills, H F; Paster, B J; Dewhirst, F E; Yan, L; Palley, L; Prostak, K

1993-10-01

Profound diarrhea associated with proliferating intestinal cells containing intraepithelial campylobacter-like organisms (ICLO) occurs in a variety of mammalian hosts, particularly swine and hamsters. Recently, intracellular bacteria were isolated from proliferative intestinal tissue of hamsters and propagated in intestine cell line 407. Oral inoculation of hamsters with cell culture lysates containing these organisms reproduced the disease in susceptible hamsters. In the present study, an intracellular bacterium from the INT 407 cell line was shown by a variety of techniques to be a member of the genus Chlamydia and has been designated Chlamydia sp. strain SFPD. McCoy cells infected with Chlamydia sp. strain SFPD demonstrated bright fluorescent-stained intracytoplasmic inclusions when examined with fluorescein-labeled species-specific C. trachomatis monoclonal antibodies. The organism also reacted to fluorescein-labeled polyclonal but not monoclonal ICLO "omega" antisera. Ultrastructural examination of the Chlamydia sp. strain SFPD from McCoy cells revealed electrondense elementary bodies and a less electron-dense reticulate-like body that was circular; both features are consistent in morphology to developmental forms of Chlamydia and do not conform to ICLO morphology. Molecular studies, 16S ribosomal sequence analysis, and sequencing of the outer membrane protein confirmed that the isolate is a C. trachomatis closely related to the mouse pneumonitis strain of C. trachomatis.

Chlamydia psittaci in birds of prey, Sweden

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Maria Blomqvist

2012-05-01

Full Text Available Background: Chlamydia psittaci is an intracellular bacterium primarily causing respiratory diseases in birds but may also be transmitted to other animals, including humans. The prevalence of the pathogen in wild birds in Sweden is largely unknown. Methods: DNA was extracted from cloacae swabs and screened for C. psittaci by using a 23S rRNA gene PCR assay. Partial 16S rRNA and ompA gene fragments were sequence determined and phylogenies were analysed by the neighbour-joining method. Results and conclusion: The C. psittaci prevalence was 1.3% in 319 Peregrine Falcons and White-tailed Sea Eagles, vulnerable top-predators in Sweden. 16S rRNA and ompA gene analysis showed that novel Chlamydia species, as well as novel C. psittaci strains, are to be found among wild birds.

Comprehensive in silico prediction and analysis of chlamydial outer membrane proteins reflects evolution and life style of the Chlamydiae

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Myers Garry

2009-12-01

Full Text Available Abstract Background Chlamydiae are obligate intracellular bacteria comprising some of the most important bacterial pathogens of animals and humans. Although chlamydial outer membrane proteins play a key role for attachment to and entry into host cells, only few have been described so far. We developed a comprehensive, multiphasic in silico approach, including the calculation of clusters of orthologues, to predict outer membrane proteins using conservative criteria. We tested this approach using Escherichia coli (positive control and Bacillus subtilis (negative control, and applied it to five chlamydial species; Chlamydia trachomatis, Chlamydia muridarum, Chlamydia (a.k.a. Chlamydophila pneumoniae, Chlamydia (a.k.a. Chlamydophila caviae, and Protochlamydia amoebophila. Results In total, 312 chlamydial outer membrane proteins and lipoproteins in 88 orthologous clusters were identified, including 238 proteins not previously recognized to be located in the outer membrane. Analysis of their taxonomic distribution revealed an evolutionary conservation among Chlamydiae, Verrucomicrobia, Lentisphaerae and Planctomycetes as well as lifestyle-dependent conservation of the chlamydial outer membrane protein composition. Conclusion This analysis suggested a correlation between the outer membrane protein composition and the host range of chlamydiae and revealed a common set of outer membrane proteins shared by these intracellular bacteria. The collection of predicted chlamydial outer membrane proteins is available at the online database pCOMP http://www.microbial-ecology.net/pcomp and might provide future guidance in the quest for anti-chlamydial vaccines.

Inhibition of Wnt Signaling Pathways Impairs Chlamydia trachomatis Infection in Endometrial Epithelial Cells.

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Kintner, Jennifer; Moore, Cheryl G; Whittimore, Judy D; Butler, Megan; Hall, Jennifer V

2017-01-01

Chlamydia trachomatis infections represent the predominant cause of bacterial sexually transmitted infections. As an obligate intracellular bacterium, C. trachomatis is dependent on the host cell for survival, propagation, and transmission. Thus, factors that affect the host cell, including nutrition, cell cycle, and environmental signals, have the potential to impact chlamydial development. Previous studies have demonstrated that activation of Wnt/β-catenin signaling benefits C. trachomatis infections in fallopian tube epithelia. In cervical epithelial cells chlamydiae sequester β-catenin within the inclusion. These data indicate that chlamydiae interact with the Wnt signaling pathway in both the upper and lower female genital tract (FGT). However, hormonal activation of canonical and non-canonical Wnt signaling pathways is an essential component of cyclic remodeling in another prominent area of the FGT, the endometrium. Given this information, we hypothesized that Wnt signaling would impact chlamydial infection in endometrial epithelial cells. To investigate this hypothesis, we analyzed the effect of Wnt inhibition on chlamydial inclusion development and elementary body (EB) production in two endometrial cell lines, Ishikawa (IK) and Hec-1B, in nonpolarized cell culture and in a polarized endometrial epithelial (IK)/stromal (SHT-290) cell co-culture model. Inhibition of Wnt by the small molecule inhibitor (IWP2) significantly decreased inclusion size in IK and IK/SHT-290 cultures ( p Wnt inhibition caused chlamydiae to become aberrant in morphology. EB formation was also impaired in IK, Hec-1B and IK/SHT-290 cultures regardless of whether Wnt inhibition occurred throughout, in the middle (24 hpi) or late (36 hpi) during the development cycle. Overall, these data lead us to conclude that Wnt signaling in the endometrium is a key host pathway for the proper development of C. trachomatis .

Characterization of interactions between inclusion membrane proteins from Chlamydia trachomatis

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Emilie eGauliard

2015-02-01

Full Text Available Chlamydiae are obligate intracellular pathogens of eukaryotes. The bacteria grow in an intracellular vesicle called an inclusion, the membrane of which is heavily modified by chlamydial proteins called Incs (Inclusion membrane proteins. Incs represent 7-10% of the genomes of Chlamydia and, given their localization at the interface between the host and the pathogen, likely play a key role in the development and pathogenesis of the bacterium. However, their functions remain largely unknown. Here, we characterized the interaction properties between various Inc proteins of C. trachomatis, using a bacterial two-hybrid (BACTH method suitable for detecting interactions between integral membrane proteins. To validate this approach, we first examined the oligomerization properties of the well-characterized IncA protein and showed that both the cytoplasmic domain and the transmembrane region independently contribute to IncA oligomerization. We then analyzed a set of Inc proteins and identified novel interactions between these components. Two small Incs, IncF and Ct222, were found here to interact with many other Inc proteins and may thus represent interaction nodes within the inclusion membrane. Our data suggest that the Inc proteins may assemble in the membrane of the inclusion to form specific multi-molecular complexes in an hierarchical and temporal manner. These studies will help to better define the putative functions of the Inc proteins in the infectious process of Chlamydia.

Brucella abortus Induces a Warburg Shift in Host Metabolism That Is Linked to Enhanced Intracellular Survival of the Pathogen.

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Czyż, Daniel M; Willett, Jonathan W; Crosson, Sean

2017-08-01

Intracellular bacterial pathogens exploit host cell resources to replicate and survive inside the host. Targeting these host systems is one promising approach to developing novel antimicrobials to treat intracellular infections. We show that human macrophage-like cells infected with Brucella abortus undergo a metabolic shift characterized by attenuated tricarboxylic acid cycle metabolism, reduced amino acid consumption, altered mitochondrial localization, and increased lactate production. This shift to an aerobic glycolytic state resembles the Warburg effect, a change in energy production that is well described in cancer cells and also occurs in activated inflammatory cells. B. abortus efficiently uses lactic acid as its sole carbon and energy source and requires the ability to metabolize lactate for normal survival in human macrophage-like cells. We demonstrate that chemical inhibitors of host glycolysis and lactate production do not affect in vitro growth of B. abortus in axenic culture but decrease its survival in the intracellular niche. Our data support a model in which infection shifts host metabolism to a Warburg-like state, and B. abortus uses this change in metabolism to promote intracellular survival. Pharmacological perturbation of these features of host cell metabolism may be a useful strategy to inhibit infection by intracellular pathogens. IMPORTANCE Brucella spp. are intracellular bacterial pathogens that cause disease in a range of mammals, including livestock. Transmission from livestock to humans is common and can lead to chronic human disease. Human macrophage-like cells infected with Brucella abortus undergo a Warburg-like metabolic shift to an aerobic glycolytic state where the host cells produce lactic acid and have reduced amino acid catabolism. We provide evidence that the pathogen can exploit this change in host metabolism to support growth and survival in the intracellular niche. Drugs that inhibit this shift in host cell metabolism

Chlamydia abortus YhbZ, a truncated Obg family GTPase, associates with the Escherichia coli large ribosomal subunit.

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Polkinghorne, Adam; Vaughan, Lloyd

2011-01-01

The stringent stress response is vital for bacterial survival under adverse environmental conditions. Obligate intracellular Chlamydia lack key stringent response proteins, but nevertheless can interrupt the cell cycle and enter stasis or persistence upon amino acid starvation. A possible key protein retained is YhbZ, a homologue of the ObgE guanosine triphosphatase (GTPase) superfamily connecting the stringent stress response to ribosome maturation. Curiously, chlamydial YhbZ lacks the ObgE C-terminal domain thought to be essential for binding the large ribosomal subunit. We expressed recombinant Chlamydia abortus YhbZ and showed it to be a functional GTPase, with similar activity to other Obg GTPase family members. As Chlamydia are resistant to genetic manipulation, we performed heterologous expression and gradient centrifugation experiments in Escherichia coli and found that, despite the missing C-terminal domain, C. abortus YhbZ co-fractionates with the E. coli 50S large ribosomal subunit. In addition, overexpression of chlamydial YhbZ in E. coli leads to growth defects and elongation, as reported for other Obg members. YhbZ did not complement an E. coli obgE temperature-sensitive mutant, indicating the C-terminal acidic domain may have an additional role. This data supports a role for YhbZ linking the chlamydial stress response to ribosome function and cellular growth. Copyright © 2010 Elsevier Ltd. All rights reserved.

Identification and characterization of a novel Chlamydia trachomatis reticulate body protein

DEFF Research Database (Denmark)

Shaw, Allan C; Larsen, Martin Røssel; Roepstorff, Peter

2002-01-01

The genome of the obligate intracellular bacterium Chlamydia trachomatis comprises 894 genes predicted by computer-based analysis. As part of a large-scale proteome analysis of C. trachomatis, a small abundant protein encoded by a previously unrecognized novel 204-bp open reading frame was identi...... cycle. The protein is rapidly degraded and is only present in reticulate or intermediate bodies, suggesting a possible function in the intracellular stage of C. trachomatis development. We have termed the protein '7-kDa reticulate body protein'....

Emendation of the family Chlamydiaceae: proposal of a single genus, Chlamydia, to include all currently recognized species.

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Sachse, Konrad; Bavoil, Patrik M; Kaltenboeck, Bernhard; Stephens, Richard S; Kuo, Cho-Chou; Rosselló-Móra, Ramon; Horn, Matthias

2015-03-01

The family Chlamydiaceae (order Chlamydiales, phylum Chlamydiae) comprises important, obligate intracellular bacterial pathogens of humans and animals. Subdivision of the family into the two genera Chlamydia and Chlamydophila has been discussed controversially during the past decade. Here, we have revisited the current classification in the light of recent genomic data and in the context of the unique biological properties of these microorganisms. We conclude that neither generally used 16S rRNA sequence identity cut-off values nor parameters based on genomic similarity consistently separate the two genera. Notably, no easily recognizable phenotype such as host preference or tissue tropism is available that would support a subdivision. In addition, the genus Chlamydophila is currently not well accepted and not used by a majority of research groups in the field. Therefore, we propose the classification of all 11 currently recognized Chlamydiaceae species in a single genus, the genus Chlamydia. Finally, we provide emended descriptions of the family Chlamydiaceae, the genus Chlamydia, as well as the species Chlamydia abortus, Chlamydia caviae and Chlamydia felis. Copyright © 2015 Elsevier GmbH. All rights reserved.

Diversification and Distribution of Ruminant Chlamydia abortus Clones Assessed by MLST and MLVA

NARCIS (Netherlands)

Siarkou, Victoria I.; Vorimore, Fabien; Vicari, Nadia; Magnino, Simone; Rodolakis, Annie; Pannekoek, Yvonne; Sachse, Konrad; Longbottom, David; Laroucau, Karine

2015-01-01

Chlamydia abortus, an obligate intracellular bacterium, is the most common infectious cause of abortion in small ruminants worldwide and has zoonotic potential. We applied multilocus sequence typing (MLST) together with multiple-locus variable-number tandem repeat analysis (MLVA) to genotype 94

[Chlamydia trachomatis proteasome protein as one of the significant pathogenicity factors of exciter].

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Davydov, D Iu; Zigangirova, N A

2014-01-01

Sex-related infections are a global problem. Such infections may lead to acute or chronic diseases. Chlamydia trachomatis is a dangerous and widespread pathogenicity factor that is not sensitive to conventional drugs and has no obvious symptoms. Protein CPAF is leading factor of pathogenesis. This protein inhibits the signaling pathways of host cell and supports long survival of the pathogen in the host cell. The goal of this work was to review general properties of the proteasome Chlamydia protein CPAF, its functions, and role in pathology. The role of protein CPAF in the anti-chlamydia immune reaction is discussed. The prospects of the development of promising anti-chlamydia vaccine, as well as new effective anti-chlamydia drugs are also discussed.

Chlamydia trachomatis Is Responsible for Lipid Vacuolation in the Amniotic Epithelium of Fetal Gastroschisis.

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Feldkamp, Marcia L; Ward, Diane M; Pysher, Theodore J; Chambers, Christina T

2017-07-17

Vacuolated amniotic epithelium with lipid droplets in gastroschisis placentas is an unusual finding. Mass spectrometry of lipid droplets identified triglycerides, ester-linked to an unusual pattern of fatty acids. We hypothesize that these findings result from a Chlamydia trachomatis infection during the periconceptional period. The rising incidence of chlamydia infections has paralleled the increasing prevalence of gastroschisis among women less than 25 years of age. Histologically, young women are at greatest risk for a chlamydia infection due to their immature columnar epithelium, the preferential site for attachment of Chlamydia trachomatis infectious particle (elementary body). Chlamydia trachomatis survive in an inclusion, relying on its host to acquire essential nutrients, amino acids, and nucleotides for survival and replication. If essential nutrients are not available, the bacteria cannot replicate and may be trafficked to the lysosome for degradation or remain quiescent, within the inclusion, subverting innate immunologic clearance. Chlamydiae synthesize several lipids (phosphatidylethanolamine, phosphatidylserine, and phosphoatidylglycerol); however, their lipid content reveal eukaryotic lipids (sphingomyelin, cholesterol, phosphatidylcholine, and phosphatidylinositol), evidence that chlamydiae "hijack" host lipids for expansion and replication. The abnormal amniotic epithelial findings are supported by experimental evidence of the trafficking of host lipids into the chlamydiae inclusion. If not lethal, what harm will elementary bodies inflict to the developing embryo? Do these women have a greater pro-inflammatory response to an environmental exposure, whether cigarette smoking, change in partner, or a pathogen? Testing the hypothesis that Chlamydia trachomatis is responsible for amniotic epithelium vacuoles will be a critical first step. Birth Defects Research 109:1003-1010, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

The Proteome of the Isolated Chlamydia trachomatis Containing Vacuole Reveals a Complex Trafficking Platform Enriched for Retromer Components.

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Lukas Aeberhard

2015-06-01

Full Text Available Chlamydia trachomatis is an important human pathogen that replicates inside the infected host cell in a unique vacuole, the inclusion. The formation of this intracellular bacterial niche is essential for productive Chlamydia infections. Despite its importance for Chlamydia biology, a holistic view on the protein composition of the inclusion, including its membrane, is currently missing. Here we describe the host cell-derived proteome of isolated C. trachomatis inclusions by quantitative proteomics. Computational analysis indicated that the inclusion is a complex intracellular trafficking platform that interacts with host cells' antero- and retrograde trafficking pathways. Furthermore, the inclusion is highly enriched for sorting nexins of the SNX-BAR retromer, a complex essential for retrograde trafficking. Functional studies showed that in particular, SNX5 controls the C. trachomatis infection and that retrograde trafficking is essential for infectious progeny formation. In summary, these findings suggest that C. trachomatis hijacks retrograde pathways for effective infection.

Pathogenic Chlamydia Lack a Classical Sacculus but Synthesize a Narrow, Mid-cell Peptidoglycan Ring, Regulated by MreB, for Cell Division.

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Liechti, George; Kuru, Erkin; Packiam, Mathanraj; Hsu, Yen-Pang; Tekkam, Srinivas; Hall, Edward; Rittichier, Jonathan T; VanNieuwenhze, Michael; Brun, Yves V; Maurelli, Anthony T

2016-05-01

The peptidoglycan (PG) cell wall is a peptide cross-linked glycan polymer essential for bacterial division and maintenance of cell shape and hydrostatic pressure. Bacteria in the Chlamydiales were long thought to lack PG until recent advances in PG labeling technologies revealed the presence of this critical cell wall component in Chlamydia trachomatis. In this study, we utilize bio-orthogonal D-amino acid dipeptide probes combined with super-resolution microscopy to demonstrate that four pathogenic Chlamydiae species each possess a ≤ 140 nm wide PG ring limited to the division plane during the replicative phase of their developmental cycles. Assembly of this PG ring is rapid, processive, and linked to the bacterial actin-like protein, MreB. Both MreB polymerization and PG biosynthesis occur only in the intracellular form of pathogenic Chlamydia and are required for cell enlargement, division, and transition between the microbe's developmental forms. Our kinetic, molecular, and biochemical analyses suggest that the development of this limited, transient, PG ring structure is the result of pathoadaptation by Chlamydia to an intracellular niche within its vertebrate host.

Pathogenic Chlamydia Lack a Classical Sacculus but Synthesize a Narrow, Mid-cell Peptidoglycan Ring, Regulated by MreB, for Cell Division.

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George Liechti

2016-05-01

Full Text Available The peptidoglycan (PG cell wall is a peptide cross-linked glycan polymer essential for bacterial division and maintenance of cell shape and hydrostatic pressure. Bacteria in the Chlamydiales were long thought to lack PG until recent advances in PG labeling technologies revealed the presence of this critical cell wall component in Chlamydia trachomatis. In this study, we utilize bio-orthogonal D-amino acid dipeptide probes combined with super-resolution microscopy to demonstrate that four pathogenic Chlamydiae species each possess a ≤ 140 nm wide PG ring limited to the division plane during the replicative phase of their developmental cycles. Assembly of this PG ring is rapid, processive, and linked to the bacterial actin-like protein, MreB. Both MreB polymerization and PG biosynthesis occur only in the intracellular form of pathogenic Chlamydia and are required for cell enlargement, division, and transition between the microbe's developmental forms. Our kinetic, molecular, and biochemical analyses suggest that the development of this limited, transient, PG ring structure is the result of pathoadaptation by Chlamydia to an intracellular niche within its vertebrate host.

Chlamydiae in febrile children with respiratory tract symptoms and age-matched controls, Ghana

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H. Bühl

2018-03-01

Full Text Available Members of the Chlamydiales order are obligate intracellular pathogens causing acute and chronic infectious diseases. Chlamydiaceae are established agents of community- and zoonotically acquired respiratory tract infections, and emerging pathogens among the Chlamydia-related bacteria have been implicated in airway infections. The role of both in airway infections in Africa is underexplored. We performed a case -control study on the prevalence of Chlamydiaceae and Chlamydia-related emerging pathogens in children with febrile respiratory tract infections in West Africa, Ghana. Using a pan-Chlamydiales broad-range real-time PCR, we detected chlamydial DNA in 11 (1.9% of 572 hospitalized febrile children with respiratory tract symptoms and in 24 (4.3% of 560 asymptomatic age-matched controls (p 0.03. Chlamydiaceae were found to be common among both symptomatic and healthy Ghanaian children, with Chlamydia pneumoniae being the most prevalent species. Parachlamydiaceae were detected in two children without symptoms but not in the symptomatic group. We identified neither Chlamydia psittaci nor Simkania negevensis but a member of a new chlamydial family that shared 90.2% sequence identity with the 16S rRNA gene of the zoonotic pathogen Chlamydia pecorum. In addition, we found a new Chlamydia-related species that belonged to a novel family sharing 91.3% 16S rRNA sequence identity with Candidatus Syngnamydia venezia. The prevalence and spectrum of chlamydial species differed from previous results obtained from children of other geographic regions and our study indicates that both, Chlamydiaceae and Chlamydia-related bacteria, are not clearly linked to clinical symptoms in Ghanaian children. Keywords: Children, Chlamydia, Chlamydia-related bacteria, febrile respiratory tract infection, Ghana

The role of TREM-2 in internalization and intracellular survival of Brucella abortus in murine macrophages.

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Wei, Pan; Lu, Qiang; Cui, Guimei; Guan, Zhenhong; Yang, Li; Sun, Changjiang; Sun, Wanchun; Peng, Qisheng

2015-02-15

Triggering receptor expressed on myeloid cells-2 (TREM-2) is a cell surface receptor primarily expressed on macrophages and dendritic cells. TREM-2 functions as a phagocytic receptor for bacteria as well as an inhibitor of Toll like receptors (TLR) induced inflammatory cytokines. However, the role of TREM-2 in Brucella intracellular growth remains unknown. To investigate whether TREM-2 is involved in Brucella intracellular survival, we chose bone marrow derived macrophages (BMDMs), in which TREM-2 is stably expressed, as cell model. Colony formation Units (CFUs) assay suggests that TREM-2 is involved in the internalization of Brucella abortus (B. abortus) by macrophages, while silencing of TREM-2 decreases intracellular survival of B. abortus. To further study the underlying mechanisms of TREM-2-mediated bacterial intracellular survival, we examined the activation of B. abortus-infected macrophages through determining the kinetics of activation of the three MAPKs, including ERK, JNK and p38, and measuring TNFα production in response to lipopolysaccharide (LPS) of Brucella (BrLPS) or B. abortus stimulation. Our data show that TREM-2 deficiency promotes activation of Brucella-infected macrophages. Moreover, our data also demonstrate that macrophage activation promotes killing of Brucella by enhancing nitric oxygen (NO), but not reactive oxygen species (ROS) production, macrophage apoptosis or cellular death. Taken together, these findings provide a novel interpretation of Brucella intracellular growth through inhibition of NO production produced by TREM-2-mediated activated macrophages. Copyright © 2014 Elsevier B.V. All rights reserved.

Microaerobic growth and anaerobic survival of Mycobacterium avium, Mycobacterium intracellulare and Mycobacterium scrofulaceum.

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Lewis, Amy Herndon; Falkinham, Joseph O

2015-03-01

Representative strains of Mycobacterium avium, Mycobacterium intracellulare and Mycobacterium scrofulaceum (MAIS) grew at equal rates in laboratory medium at 21% (air) and 12% oxygen. Growth in 6% oxygen proceeded at a 1.4-1.8-fold lower rate. Colony formation was the same at 21% (air) and 6% oxygen. The MAIS strains survived rapid shifts from aerobic to anaerobic conditions as measured by two experimental approaches (Falkinham (1996) [1]). MAIS cells grown aerobically to log phase in broth were diluted, spread on agar medium, and incubated anaerobically for up to 20 days at 37°C. Although no colonies formed anaerobically, upon transfer to aerobic conditions, greater than 25% of the colony forming units (CFU) survived after 20 days of anaerobic incubation (Prince et al. (1989) [2]). MAIS cells grown in broth aerobically to log phase were sealed and vigorous agitation led to oxygen depletion (Wayne model). After 12 days anaerobic incubation, M. avium and M. scrofulaceum survival were high (>50%), while M. intracellulare survival was lower (22%). M. avium cells shifted to anaerobiosis in broth had increased levels of glycine dehydrogenase and isocitrate lyase. Growth of MAIS strains at low oxygen levels and their survival following a rapid shift to anaerobiosis is consistent with their presence in environments with fluctuating oxygen levels. Copyright © 2015 Asian African Society for Mycobacteriology. Published by Elsevier Ltd. All rights reserved.

Microaerobic growth and anaerobic survival of Mycobacterium avium, Mycobacterium intracellulare and Mycobacterium scrofulaceum

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Amy Herndon Lewis

2015-01-01

Full Text Available Representative strains of Mycobacterium avium, Mycobacterium intracellulare and Mycobacterium scrofulaceum (MAIS grew at equal rates in laboratory medium at 21% (air and 12% oxygen. Growth in 6% oxygen proceeded at a 1.4–1.8-fold lower rate. Colony formation was the same at 21% (air and 6% oxygen. The MAIS strains survived rapid shifts from aerobic to anaerobic conditions as measured by two experimental approaches (Falkinham (1996 [1]. MAIS cells grown aerobically to log phase in broth were diluted, spread on agar medium, and incubated anaerobically for up to 20 days at 37 °C. Although no colonies formed anaerobically, upon transfer to aerobic conditions, greater than 25% of the colony forming units (CFU survived after 20 days of anaerobic incubation (Prince et al. (1989 [2]. MAIS cells grown in broth aerobically to log phase were sealed and vigorous agitation led to oxygen depletion (Wayne model. After 12 days anaerobic incubation, M. avium and M. scrofulaceum survival were high (>50%, while M. intracellulare survival was lower (22%. M. avium cells shifted to anaerobiosis in broth had increased levels of glycine dehydrogenase and isocitrate lyase. Growth of MAIS strains at low oxygen levels and their survival following a rapid shift to anaerobiosis is consistent with their presence in environments with fluctuating oxygen levels.

Dendrimer-conjugated peptide vaccine enhances clearance of Chlamydia trachomatis genital infection.

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Ganda, Ingrid S; Zhong, Qian; Hali, Mirabela; Albuquerque, Ricardo L C; Padilha, Francine F; da Rocha, Sandro R P; Whittum-Hudson, Judith A

2017-07-15

Peptide-based vaccines have emerged in recent years as promising candidates in the prevention of infectious diseases. However, there are many challenges to maintaining in vivo peptide stability and enhancement of peptide immunogenicity to generate protective immunity which enhances clearance of infections. Here, a dendrimer-based carrier system is proposed for peptide-based vaccine delivery, and shows its anti-microbial feasibility in a mouse model of Chlamydia trachomatis. Chlamydiae are the most prevalent sexually transmitted bacteria worldwide, and also the causal agent of trachoma, the leading cause of preventable infectious blindness. In spite of the prevalence of this infectious agent and the many previous vaccine-related studies, there is no vaccine commercially available. The carrier system proposed consists of generation 4, hydroxyl-terminated, polyamidoamine (PAMAM) dendrimers (G4OH), to which a peptide mimic of a chlamydial glycolipid antigen-Peptide 4 (Pep4, AFPQFRSATLLL) was conjugated through an ester bond. The ester bond between G4OH and Pep4 is expected to break down mainly in the intracellular environment for antigen presentation. Pep4 conjugated to dendrimer induced Chlamydia-specific serum antibodies after subcutaneous immunizations. Further, this new vaccine formulation significantly protected immunized animals from vaginal challenge with infectious Chlamydia trachomatis, and it reduced infectious loads and tissue (genital tract) damage. Pep4 conjugated to G4OH or only mixed with peptide provided enhanced protection compared to Pep4 and adjuvant (i.e. alum), suggesting a potential adjuvant effect of the PAMAM dendrimer. Combined, these results demonstrate that hydroxyl-terminated PAMAM dendrimer is a promising polymeric nanocarrier platform for the delivery of peptide vaccines and this approach has potential to be expanded to other infectious intracellular bacteria and viruses of public health significance. Copyright © 2017 Elsevier B.V. All

Chlamydiae in the ejaculate: their influence on the quality and morphology of sperm.

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Veznik, Zdenek; Pospisil, Leopold; Svecova, Drahomira; Zajicova, Atanaska; Unzeitig, Vit

2004-07-01

Given the lack of information concerning the role of Chlamydia trachomatis in male fertility, the aim of this study was to ascertain and analyze the quality of Chlamydiae-positive and -negative semen. Sperm count was performed according to the 1999 World Health Organization (WHO) laboratory manual for examination of human semen and sperm-cervical mucus interaction, and sperm survival was assessed by a 120-min test. The evaluation of the morphological examination of ejaculates was carried out using the sasmo (strict morphological analysis of ejaculates) computer program. Chlamydiae were detected by immunofluorescent reaction using the Progen Biotechnik GmbH diagnostic set. Fisher's exact test and the chi-quadrate test were used for statistical analysis. Of the total of 627 sperm samples examined, Chlamydiae were detected in 136 cases (21.7%). Sperm analysis showed significant differences between Chlamydiae-positive and -negative samples. The Chlamydiae-contaminated group showed normal sperm morphology 14.4% lower, volume 6.4% lower, concentration 8.3% lower, motility 7.8% and velocity 9.3% lower than in Chlamydiae-negative samples. The average values for normal spermatozoa and motility in the Chlamydiae-positive group were also significantly reduced. Chlamydia trachomatis was found to be a possible factor in sperm pathology. These results could help to elucidate the role of Chlamydia trachomatis in male infertility.

Attachment and entry of Chlamydia have distinct requirements for host protein disulfide isomerase.

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Stephanie Abromaitis

2009-04-01

Full Text Available Chlamydia is an obligate intracellular pathogen that causes a wide range of diseases in humans. Attachment and entry are key processes in infectivity and subsequent pathogenesis of Chlamydia, yet the mechanisms governing these interactions are unknown. It was recently shown that a cell line, CHO6, that is resistant to attachment, and thus infectivity, of multiple Chlamydia species has a defect in protein disulfide isomerase (PDI N-terminal signal sequence processing. Ectopic expression of PDI in CHO6 cells led to restoration of Chlamydia attachment and infectivity; however, the mechanism leading to this recovery was not ascertained. To advance our understanding of the role of PDI in Chlamydia infection, we used RNA interference to establish that cellular PDI is essential for bacterial attachment to cells, making PDI the only host protein identified as necessary for attachment of multiple species of Chlamydia. Genetic complementation and PDI-specific inhibitors were used to determine that cell surface PDI enzymatic activity is required for bacterial entry into cells, but enzymatic function was not required for bacterial attachment. We further determined that it is a PDI-mediated reduction at the cell surface that triggers bacterial uptake. While PDI is necessary for Chlamydia attachment to cells, the bacteria do not appear to utilize plasma membrane-associated PDI as a receptor, suggesting that Chlamydia binds a cell surface protein that requires structural association with PDI. Our findings demonstrate that PDI has two essential and independent roles in the process of chlamydial infectivity: it is structurally required for chlamydial attachment, and the thiol-mediated oxido-reductive function of PDI is necessary for entry.

Epigenetic silencing of host cell defense genes enhances intracellular survival of the rickettsial pathogen Anaplasma phagocytophilum.

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Jose C Garcia-Garcia

2009-06-01

Full Text Available Intracellular bacteria have evolved mechanisms that promote survival within hostile host environments, often resulting in functional dysregulation and disease. Using the Anaplasma phagocytophilum-infected granulocyte model, we establish a link between host chromatin modifications, defense gene transcription and intracellular bacterial infection. Infection of THP-1 cells with A. phagocytophilum led to silencing of host defense gene expression. Histone deacetylase 1 (HDAC1 expression, activity and binding to the defense gene promoters significantly increased during infection, which resulted in decreased histone H3 acetylation in infected cells. HDAC1 overexpression enhanced infection, whereas pharmacologic and siRNA HDAC1 inhibition significantly decreased bacterial load. HDAC2 does not seem to be involved, since HDAC2 silencing by siRNA had no effect on A. phagocytophilum intracellular propagation. These data indicate that HDAC up-regulation and epigenetic silencing of host cell defense genes is required for A. phagocytophilum infection. Bacterial epigenetic regulation of host cell gene transcription could be a general mechanism that enhances intracellular pathogen survival while altering cell function and promoting disease.

Taking control: reorganization of the host cytoskeleton by Chlamydia [version 1; referees: 5 approved

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Jordan Wesolowski

2017-11-01

Full Text Available Both actin and microtubules are major cytoskeletal elements in eukaryotic cells that participate in many cellular processes, including cell division and motility, vesicle and organelle movement, and the maintenance of cell shape. Inside its host cell, the human pathogen Chlamydia trachomatis manipulates the cytoskeleton to promote its survival and enhance its pathogenicity. In particular, Chlamydia induces the drastic rearrangement of both actin and microtubules, which is vital for its entry, inclusion structure and development, and host cell exit. As significant progress in Chlamydia genetics has greatly enhanced our understanding of how this pathogen co-opts the host cytoskeleton, we will discuss the machinery used by Chlamydia to coordinate the reorganization of actin and microtubules.

Chlamydia induces anchorage independence in 3T3 cells and detrimental cytological defects in an infection model.

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Andrea E Knowlton

Full Text Available Chlamydia are gram negative, obligate intracellular bacterial organisms with different species causing a multitude of infections in both humans and animals. Chlamydia trachomatis is the causative agent of the sexually transmitted infection (STI Chlamydia, the most commonly acquired bacterial STI in the United States. Chlamydial infections have also been epidemiologically linked to cervical cancer in women co-infected with the human papillomavirus (HPV. We have previously shown chlamydial infection results in centrosome amplification and multipolar spindle formation leading to chromosomal instability. Many studies indicate that centrosome abnormalities, spindle defects, and chromosome segregation errors can lead to cell transformation. We hypothesize that the presence of these defects within infected dividing cells identifies a possible mechanism for Chlamydia as a cofactor in cervical cancer formation. Here we demonstrate that infection with Chlamydia trachomatis is able to transform 3T3 cells in soft agar resulting in anchorage independence and increased colony formation. Additionally, we show for the first time Chlamydia infects actively replicating cells in vivo. Infection of mice with Chlamydia results in significantly increased cell proliferation within the cervix, and in evidence of cervical dysplasia. Confocal examination of these infected tissues also revealed elements of chlamydial induced chromosome instability. These results contribute to a growing body of data implicating a role for Chlamydia in cervical cancer development and suggest a possible molecular mechanism for this effect.

Flow cytometry as an improved method for the titration of Chlamydiaceae and other intracellular bacteria.

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Käser, T; Pasternak, J A; Hamonic, G; Rieder, M; Lai, K; Delgado-Ortega, M; Gerdts, V; Meurens, F

2016-05-01

Chlamydiaceae is a family of intracellular bacteria causing a range of diverse pathological outcomes. The most devastating human diseases are ocular infections with C. trachomatis leading to blindness and genital infections causing pelvic inflammatory disease with long-term sequelae including infertility and chronic pelvic pain. In order to enable the comparison of experiments between laboratories investigating host-chlamydia interactions, the infectious titer has to be determined. Titer determination of chlamydia is most commonly performed via microscopy of host cells infected with a serial dilution of chlamydia. However, other methods including fluorescent ELISpot (Fluorospot) and DNA Chip Scanning Technology have also been proposed to enumerate chlamydia-infected cells. For viruses, flow cytometry has been suggested as a superior alternative to standard titration methods. In this study we compared the use of flow cytometry with microscopy and Fluorospot for the titration of C. suis as a representative of other intracellular bacteria. Titer determination via Fluorospot was unreliable, while titration via microscopy led to a linear read-out range of 16 - 64 dilutions and moderate reproducibility with acceptable standard deviations within and between investigators. In contrast, flow cytometry had a vast linear read-out range of 1,024 dilutions and the lowest standard deviations given a basic training in these methods. In addition, flow cytometry was faster and material costs were lower compared to microscopy. Flow cytometry offers a fast, cheap, precise, and reproducible alternative for the titration of intracellular bacteria like C. suis. © 2016 International Society for Advancement of Cytometry. © 2016 International Society for Advancement of Cytometry.

Prevalence of chlamydia infection using chlamydia antigen ...

African Journals Online (AJOL)

Abstract. Background and Objectives: Tubal disease is often associated with persistent chlamydia trachomatis infection. The objective detection of this infection depends on tissue culture which is time consuming and expensive. Serologic techniques for chlamydia detection have been documented. While this may be rapid, ...

Candidatus Syngnamydia venezia, a novel member of the phylum Chlamydiae from the broad nosed pipefish, Syngnathus typhle.

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Alexander Fehr

Full Text Available Chlamydia are obligate intracellular bacteria and important pathogens of humans and animals. Chlamydia-related bacteria are also major fish pathogens, infecting epithelial cells of the gills and skin to cause the disease epitheliocystis. Given the wide distribution, ancient origins and spectacular diversity of bony fishes, this group offers a rich resource for the identification and isolation of novel Chlamydia. The broad-nosed pipefish (Syngnathus typhle is a widely distributed and genetically diverse temperate fish species, susceptible to epitheliocystis across much of its range. We describe here a new bacterial species, Candidatus Syngnamydia venezia; epitheliocystis agent of S. typhle and close relative to other chlamydial pathogens which are known to infect diverse hosts ranging from invertebrates to humans.

Chlamydia, Gonorrhea, and Syphilis

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... Education & Events Advocacy For Patients About ACOG Chlamydia, Gonorrhea, and Syphilis Home For Patients Search FAQs Chlamydia, ... and Syphilis FAQ071, December 2016 PDF Format Chlamydia, Gonorrhea, and Syphilis Gynecologic Problems What is a sexually ...

Lead Discovery Strategies for Identification of Chlamydia pneumoniae Inhibitors

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Leena Hanski

2016-11-01

Full Text Available Throughout its known history, the gram-negative bacterium Chlamydia pneumoniae has remained a challenging target for antibacterial chemotherapy and drug discovery. Owing to its well-known propensity for persistence and recent reports on antimicrobial resistence within closely related species, new approaches for targeting this ubiquitous human pathogen are urgently needed. In this review, we describe the strategies that have been successfully applied for the identification of nonconventional antichlamydial agents, including target-based and ligand-based virtual screening, ethnopharmacological approach and pharmacophore-based design of antimicrobial peptide-mimicking compounds. Among the antichlamydial agents identified via these strategies, most translational work has been carried out with plant phenolics. Thus, currently available data on their properties as antichlamydial agents are described, highlighting their potential mechanisms of action. In this context, the role of mitogen-activated protein kinase activation in the intracellular growth and survival of C. pneumoniae is discussed. Owing to the complex and often complementary pathways applied by C. pneumoniae in the different stages of its life cycle, multitargeted therapy approaches are expected to provide better tools for antichlamydial therapy than agents with a single molecular target.

Lead Discovery Strategies for Identification of Chlamydia pneumoniae Inhibitors.

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Hanski, Leena; Vuorela, Pia

2016-11-28

Throughout its known history, the gram-negative bacterium Chlamydia pneumoniae has remained a challenging target for antibacterial chemotherapy and drug discovery. Owing to its well-known propensity for persistence and recent reports on antimicrobial resistence within closely related species, new approaches for targeting this ubiquitous human pathogen are urgently needed. In this review, we describe the strategies that have been successfully applied for the identification of nonconventional antichlamydial agents, including target-based and ligand-based virtual screening, ethnopharmacological approach and pharmacophore-based design of antimicrobial peptide-mimicking compounds. Among the antichlamydial agents identified via these strategies, most translational work has been carried out with plant phenolics. Thus, currently available data on their properties as antichlamydial agents are described, highlighting their potential mechanisms of action. In this context, the role of mitogen-activated protein kinase activation in the intracellular growth and survival of C . pneumoniae is discussed. Owing to the complex and often complementary pathways applied by C. pneumoniae in the different stages of its life cycle, multitargeted therapy approaches are expected to provide better tools for antichlamydial therapy than agents with a single molecular target.

Chlamydia pneumoniae hides inside apoptotic neutrophils to silently infect and propagate in macrophages.

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Jan Rupp

Full Text Available BACKGROUND: Intracellular pathogens have developed elaborate strategies for silent infection of preferred host cells. Chlamydia pneumoniae is a common pathogen in acute infections of the respiratory tract (e.g. pneumonia and associated with chronic lung sequelae in adults and children. Within the lung, alveolar macrophages and polymorph nuclear neutrophils (PMN are the first line of defense against bacteria, but also preferred host phagocytes of chlamydiae. METHODOLOGY/PRINCIPAL FINDINGS: We could show that C. pneumoniae easily infect and hide inside neutrophil granulocytes until these cells become apoptotic and are subsequently taken up by macrophages. C. pneumoniae infection of macrophages via apoptotic PMN results in enhanced replicative activity of chlamydiae when compared to direct infection of macrophages, which results in persistence of the pathogen. Inhibition of the apoptotic recognition of C. pneumoniae infected PMN using PS- masking Annexin A5 significantly lowered the transmission of chlamydial infection to macrophages. Transfer of apoptotic C. pneumoniae infected PMN to macrophages resulted in an increased TGF-ss production, whereas direct infection of macrophages with chlamydiae was characterized by an enhanced TNF-alpha response. CONCLUSIONS/SIGNIFICANCE: Taken together, our data suggest that C. pneumoniae uses neutrophil granulocytes to be silently taken up by long-lived macrophages, which allows for efficient propagation and immune protection within the human host.

Prevalence of Chlamydia psittaci and Other Chlamydia Species in Wild Birds in Poland.

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Krawiec, Marta; Piasecki, Tomasz; Wieliczko, Alina

2015-11-01

Avian chlamydiosis is a zoonotic disease occurring in humans, poultry, and exotic birds. It has been suggested that some wild bird species play an important role as reservoirs for Chlamydia, especially Chlamydia psittaci. Whereas C. psittaci is the predominant chlamydial agent in birds, in the present study we have determined the prevalence of different species of Chlamydia among selected wild bird species in Poland using a rapid and sensitive real-time PCR method. In total, 369 free-living birds from 35 bird species and 15 orders were examined. Samples from 27 birds (7.3%) were positive for chlamydial DNA in the PCR; 22 positive samples (81.5%) belonged to C. psittaci, three to Chlamydia trachomatis (11.1%), and two (7.4%) classified only to the genus Chlamydia. Most of C. psittaci-positive samples belonged to five orders: Anseriformes, Columbiformes, Gruiformes, Phasianiformes, and Passeriformes. All C. trachomatis samples were obtained from Eurasian coots (Gruiformes). Two Chlamydia-positive samples not classified to any Chlamydia species were obtained from a common wood pigeon (Columbiformes) and a common buzzard (Accipitriformes). Detection of C. psittaci and C. trachomatis in free-living bird populations force to think on significance of birds as reservoir of varied Chlamydia species and their epidemiological importance.

Serological and nested PCR survey to determine the occurrence of Chlamydia infections in the Polish cattle population.

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Szymańska-Czerwińska, Monika; Niemczuk, Krzysztof; Galińska, Elżbieta Monika

2013-01-01

Chlamydia spp. is an obligate intracellular agent that causes chlamydiosis in animals and humans. The aim of the presented study was to investigate the prevalence of Chlamydia infection in the Polish cattle population, both asymptomatic and having reproductive disorders. The study was performed on 4,475 serum samples collected from 16 Polish provinces at the turn of 2009-2011. The samples (3,419 from asymptomatic cattle and 1,056 from cattle with reproductive disorders) were tested by complement fixation test (CFT). Moreover, 160 and 201 samples of biological materials from both groups of cattle, respectively, were tested by nested PCR. The results obtained for two tested groups were compared by χ2 (ch-squared) test, both individually for each region (province), and generally for the whole country. The CFT results showed that the seroprevalence of Chlamydia spp. infections in the asymptomatic cattle population was 4.15%, while in the cattle with reproductive disorders--7.20%. There was a significant statistical difference between compared groups for whole country, but there were no significant differences for individual provinces. The results of PCR showed that Chlamydia spp. was present in both asymptomatic cattle and cattle having reproductive disorders. The nested PCR study confirmed the presence of Chlamydia abortus and Chlamydia suis in the tested samples. The presented study indicates that infections with Chlamydia spp. are present among Polish cattle, but the percentage of infected animals is not high.

Fierce competition between Toxoplasma and Chlamydia for host cell structures in dually infected cells.

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Romano, Julia D; de Beaumont, Catherine; Carrasco, Jose A; Ehrenman, Karen; Bavoil, Patrik M; Coppens, Isabelle

2013-02-01

The prokaryote Chlamydia trachomatis and the protozoan Toxoplasma gondii, two obligate intracellular pathogens of humans, have evolved a similar modus operandi to colonize their host cell and salvage nutrients from organelles. In order to gain fundamental knowledge on the pathogenicity of these microorganisms, we have established a cell culture model whereby single fibroblasts are coinfected by C. trachomatis and T. gondii. We previously reported that the two pathogens compete for the same nutrient pools in coinfected cells and that Toxoplasma holds a significant competitive advantage over Chlamydia. Here we have expanded our coinfection studies by examining the respective abilities of Chlamydia and Toxoplasma to co-opt the host cytoskeleton and recruit organelles. We demonstrate that the two pathogen-containing vacuoles migrate independently to the host perinuclear region and rearrange the host microtubular network around each vacuole. However, Toxoplasma outcompetes Chlamydia to the host microtubule-organizing center to the detriment of the bacterium, which then shifts to a stress-induced persistent state. Solely in cells preinfected with Chlamydia, the centrosomes become associated with the chlamydial inclusion, while the Toxoplasma parasitophorous vacuole displays growth defects. Both pathogens fragment the host Golgi apparatus and recruit Golgi elements to retrieve sphingolipids. This study demonstrates that the productive infection by both Chlamydia and Toxoplasma depends on the capability of each pathogen to successfully adhere to a finely tuned developmental program that aims to remodel the host cell for the pathogen's benefit. In particular, this investigation emphasizes the essentiality of host organelle interception by intravacuolar pathogens to facilitate access to nutrients.

Penicillin kills Chlamydia following the fusion of bacteria with lysosomes and prevents genital inflammatory lesions in C. muridarum-infected mice.

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Maud Dumoux

Full Text Available The obligate intracellular bacterium Chlamydia exists as two distinct forms. Elementary bodies (EBs are infectious and extra-cellular, whereas reticulate bodies (RBs replicate within a specialized intracellular compartment termed an 'inclusion'. Alternative persistent intra-cellular forms can be induced in culture by diverse stimuli such as IFNγ or adenosine/EHNA. They do not grow or divide but revive upon withdrawal of the stimulus and are implicated in several widespread human diseases through ill-defined in vivo mechanisms. β-Lactam antibiotics have also been claimed to induce persistence in vitro. The present report shows that upon penicillin G (pG treatment, inclusions grow as fast as those in infected control cells. After removal of pG, Chlamydia do not revert to RBs. These effects are independent of host cell type, serovar, biovar and species of Chlamydia. Time-course experiments demonstrated that only RBs were susceptible to pG. pG-treated bacteria lost their control over host cell apoptotic pathways and no longer expressed pre-16S rRNA, in contrast to persistent bacteria induced with adenosine/EHNA. Confocal and live-video microscopy showed that bacteria within the inclusion fused with lysosomal compartments in pG-treated cells. That leads to recruitment of cathepsin D as early as 3 h post pG treatment, an event preceding bacterial death by several hours. These data demonstrate that pG treatment of cultured cells infected with Chlamydia results in the degradation of the bacteria. In addition we show that pG is significantly more efficient than doxycycline at preventing genital inflammatory lesions in C. muridarum-C57Bl/6 infected mice. These in vivo results support the physiological relevance of our findings and their potential therapeutic applications.

Zoonotic transmission of Chlamydia psittaci in a chicken and turkey hatchery

OpenAIRE

Dickx, Veerle; Vanrompay, Daisy

2011-01-01

Chlamydia psittaci is an obligately intracellular Gram-negative bacterium causing respiratory disease (chlamydiosis) or asymptomatic carriage in birds. C. psittaci is a zoonotic agent causing psittacosis or parrot fever in humans. Vertical and/or horizontal transmission via eggs might have serious repercussions on the C. psittaci infection status of poultry flocks and thus on zoonotic risk for all workers along the poultry supply chain. We therefore studied the presence of C. psittaci in a ha...

Improving the molecular diagnosis of Chlamydia psittaci and Chlamydia abortus infection with a species-specific duplex real-time PCR.

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Opota, Onya; Jaton, Katia; Branley, James; Vanrompay, Daisy; Erard, Veronique; Borel, Nicole; Longbottom, David; Greub, Gilbert

2015-10-01

Chlamydia psittaci and Chlamydia abortus are closely related intracellular bacteria exhibiting different tissue tropism that may cause severe but distinct infection in humans. C. psittaci causes psittacosis, a respiratory zoonotic infection transmitted by birds. C. abortus is an abortigenic agent in small ruminants, which can also colonize the human placenta and lead to foetal death and miscarriage. Infections caused by C. psittaci and C. abortus are underestimated mainly due to diagnosis difficulties resulting from their strict intracellular growth. We developed a duplex real-time PCR to detect and distinguish these two bacteria in clinical samples. The first PCR (PCR1) targeted a sequence of the 16S-23S rRNA operon allowing the detection of both C. psittaci and C. abortus. The second PCR (PCR2) targeted the coding DNA sequence CPSIT_0607 unique to C. psittaci. The two PCRs showed 100 % detection for ≥ 10 DNA copies per reaction (1000 copies ml(- 1)). Using a set of 120 samples, including bacterial reference strains, clinical specimens and infected cell culture material, we monitored 100 % sensitivity and 100 % specificity for the detection of C. psittaci and C. abortus for PCR1. When PCR1 was positive, PCR2 could discriminate C. psittaci from C. abortus with a positive predictive value of 100 % and a negative predictive value of 88 %. In conclusion, this new duplex PCR represents a low-cost and time-saving method with high-throughput potential, expected to improve the routine diagnosis of psittacosis and pregnancy complication in large-scale screening programs and also during outbreaks.

Relation of intracellular cyclic AMP to the shape of mammalian cell survival curves

International Nuclear Information System (INIS)

Lehnert, S.

1975-01-01

Results of experiments with V79 cells growing in tissue culture indicate that the reproductive survival of cells following irradiation is influenced by the level of intracellular 3', 5'-cyclic adenosine monophosphate (cyclic AMP) at the time of irradiation. Cells containing high levels of cyclic AMP induced by treatments with drugs show a characteristic survival curve in which the extent of the shoulder is increased so that the survival after low doses is enhanced. The exponential slope or D 0 , however, is decreased so that at high doses the survival of cells containing high levels of cyclic AMP may be less than that of controls. Naturally occurring changes in radiosensitivity such as those observed as cells pass through the division cycle, may also be related to parallel changes in cyclic AMP concentration occurring during the cycle. Injection of mice with compounds producing elevated cyclic AMP prior to whole-body irradiation increases survival at seven days post-irradiation. The shape of the survival curve for intestinal stem cells in these mice differs from that of the control in having an increased extrapolation number; no change in D 0 is observed in this in vivo situation. (author)

The β-hemolysin and intracellular survival of Streptococcus agalactiae in human macrophages.

Science.gov (United States)

Sagar, Anubha; Klemm, Carolin; Hartjes, Lara; Mauerer, Stefanie; van Zandbergen, Ger; Spellerberg, Barbara

2013-01-01

S. agalactiae (group B streptococci, GBS) is a major microbial pathogen in human neonates and causes invasive infections in pregnant women and immunocompromised individuals. The S. agalactiae β-hemolysin is regarded as an important virulence factor for the development of invasive disease. To examine the role of β-hemolysin in the interaction with professional phagocytes, the THP-1 monocytic cell line and human granulocytes were infected with a serotype Ia S. agalactiae wild type strain and its isogenic nonhemolytic mutant. We could show that the nonhemolytic mutants were able to survive in significantly higher numbers than the hemolytic wild type strain, in THP-1 macrophage-like cells and in assays with human granulocytes. Intracellular bacterial multiplication, however, could not be observed. The hemolytic wild type strain stimulated a significantly higher release of Tumor Necrosis Factor-α than the nonhemolytic mutant in THP-1 cells, while similar levels of the chemokine Interleukin-8 were induced. In order to investigate bacterial mediators of IL-8 release in this setting, purified cell wall preparations from both strains were tested and found to exert a potent proinflammatory stimulus on THP-1 cells. In conclusion, our results indicate that the β-hemolysin has a strong influence on the intracellular survival of S. agalactiae and that a tightly controlled regulation of β-hemolysin expression is required for the successful establishment of S. agalactiae in different host niches.

Treatment of Chlamydia-associated ocular disease via a recombinant protein based vaccine in the koala (Phascolarctos cinereus).

Science.gov (United States)

Waugh, Courtney; Austin, Ray; Polkinghorne, Adam; Timms, Peter

2016-11-01

Koalas (Phascolarctos cinereus) are affected by debilitating chlamydial disease that can lead to blindness, infertility, and death. The causative agent is the intracellular bacterium Chlamydia pecorum. While antibiotics can be used to treat koala chlamydial infection, they are often ineffective or cause severe dysbiosis to the animal's unique gut flora. Recent work has progressed on the development of a protective vaccine for Chlamydia in the koala. This study demonstrates that the use of a vaccine can have a positive effect in koalas already with clinical signs of ocular disease, suggesting a possible therapeutic effect and an alternative to antibiotic therapy. Copyright © 2016 International Alliance for Biological Standardization. All rights reserved.

Development of an in vivo model of Chlamydia abortus chronic infection in mice overexpressing IL-10.

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Del Río, Laura; Murcia, Antonio; Buendía, Antonio J; Álvarez, Daniel; Ortega, Nieves; Navarro, José A; Salinas, Jesús; Caro, María Rosa

2018-01-01

Chlamydia abortus, like other members of the family Chlamydiaceae, have a unique intracellular developmental cycle that is characterized by its chronic nature. Infection of a flock can remain undetected for months, until abortion occurs the following reproductive season but, to date, neither the location nor the mechanisms that maintain this latent phase are fully understood. Studies have shown that IL-10 produced as a response to certain micro-organisms sustains the intracellular survival of pathogens and increases host susceptibility to chlamydial infections. In order to induce a sustained infection C. abortus, transgenic mice that constitutively express IL-10 were infected and the immunological mechanisms that maintain infection in these mice were compared with the mechanisms of a resistant wild-type mouse strain. Viable bacteria could be detected in different tissues of transgenic mice up to 28 days after infection, as analysed by bacterial isolation and immunohistochemistry. Chronic infection in these mice was associated with an impaired recruitment of macrophages, decreased iNOS activity at the site of infection and a more diffuse distribution of inflammatory cells in the liver. This murine model can be of great help for understanding the immunological and bacterial mechanisms that lead to chronic chlamydial infections. Copyright © 2017 Elsevier B.V. All rights reserved.

Dextran sulfate sodium upregulates MAPK signaling for the uptake and subsequent intracellular survival of Brucella abortus in murine macrophages.

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Reyes, Alisha Wehdnesday Bernardo; Arayan, Lauren Togonon; Simborio, Hannah Leah Tadeja; Hop, Huynh Tan; Min, WonGi; Lee, Hu Jang; Kim, Dong Hee; Chang, Hong Hee; Kim, Suk

2016-02-01

Brucellosis is one of the major zoonoses worldwide that inflicts important health problems in animal and human. Here, we demonstrated that dextran sulfate sodium (DSS) significantly increased adhesion of Brucella (B.) abortus in murine macrophages compared to untreated cells. Even without infection, Brucella uptake into macrophages increased and F-actin reorganization was induced compared with untreated cells. Furthermore, DSS increased the phosphorylation of MAPKs (ERK1/2 and p38α) in Brucella-infected, DSS-treated cells compared with the control cells. Lastly, DSS markedly increased the intracellular survival of Brucella abortus in macrophages by up to 48 h. These results suggest that DSS enhanced the adhesion and phagocytosis of B. abortus into murine macrophages by stimulating the MAPK signaling proteins phospho-ERK1/2 and p38α and that DSS increased the intracellular survival of B. abortus by inhibiting colocalization of Brucella-containing vacuoles (BCVs) with the late endosome marker LAMP-1. This study emphasizes the enhancement of the phagocytic and intracellular modulatory effects of DSS, which may suppress the innate immune system and contribute to prolonged Brucella survival and chronic infection. Copyright © 2015 Elsevier Ltd. All rights reserved.

Molecular study and nucleotide sequencing of Chlamydia abortus isolated from aborted sheep fetuses ewes of Alborz province

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amirreza ebadi

2015-02-01

Full Text Available Chlamydia is an obligate intracellular and gram negative coccobacilli and one of the most important causes of abortion in ruminants especially in ewes. This investigation was performed with the purpose of molecular study and sequencing of Chlamydia abortus isolated from aborted sheep fetuses of Alborz Province. In this study, DNA extraction was performed on 100 samples from aborted fetuses of 32 sheep flocks from different areas of Alborz province. Then using specific primers of gene IGS-Sr- RNA, polymerase chain reaction was conducted and 10 samples were selected randomly from the positive cases were sent to Macrogene company in Korea for sequencing. In this study, 37 samples from a total of 100 aborted fetuses were positive for Chlamydia abortus. After sequencing, more than 99 percent of the positive samples were similar with sequences in gene bank. The sequencing results indicated that the samples were very similar to isolates LN554882/1, AF051935/1 and CR848038/1 of the gene bank and were in the same cluster. Also, this investigation indicated that Chlamydia abortus is one of the main reasons of ewe abortion in Alborz province.

Quantitative monitoring of the Chlamydia trachomatis developmental cycle using GFP-expressing bacteria, microscopy and flow cytometry.

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François Vromman

Full Text Available Chlamydiae are obligate intracellular bacteria. These pathogens develop inside host cells through a biphasic cycle alternating between two morphologically distinct forms, the infectious elementary body and the replicative reticulate body. Recently, C. trachomatis strains stably expressing fluorescent proteins were obtained. The fluorochromes are expressed during the intracellular growth of the microbe, allowing bacterial visualization by fluorescence microscopy. Whether they are also present in the infectious form, the elementary body, to a detectable level has not been studied. Here, we show that a C. trachomatis strain transformed with a plasmid expressing the green fluorescent protein (GFP accumulates sufficient quantities of the probe in elementary bodies for detection by microscopy and flow cytometry. Adhesion of single bacteria was detected. The precise kinetics of bacterial entry were determined by microscopy using automated procedures. We show that during the intracellular replication phase, GFP is a convenient read-out for bacterial growth with several advantages over current methods. In particular, infection rates within a non-homogenous cell population are easily quantified. Finally, in spite of their small size, individual elementary bodies are detected by flow cytometers, allowing for direct enumeration of a bacterial preparation. In conclusion, GFP-expressing chlamydiae are suitable to monitor, in a quantitative manner, progression throughout the developmental cycle. This will facilitate the identification of the developmental steps targeted by anti-chlamydial drugs or host factors.

BLAST screening of chlamydial genomes to identify signature proteins that are unique for the Chlamydiales, Chlamydiaceae, Chlamydophila and Chlamydia groups of species

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Gupta Radhey S

2006-01-01

Full Text Available Abstract Background Chlamydiae species are of much importance from a clinical viewpoint. Their diversity both in terms of their numbers as well as clinical involvement are presently believed to be significantly underestimated. The obligate intracellular nature of chlamydiae has also limited their genetic and biochemical studies. Thus, it is of importance to develop additional means for their identification and characterization. Results We have carried out analyses of available chlamydiae genomes to identify sets of unique proteins that are either specific for all Chlamydiales genomes, or different Chlamydiaceae family members, or members of the Chlamydia and Chlamydophila genera, or those unique to Protochlamydia amoebophila, but which are not found in any other bacteria. In total, 59 Chlamydiales-specific proteins, 79 Chlamydiaceae-specific proteins, 20 proteins each that are specific for both Chlamydia and Chlamydophila and 445 ORFs that are Protochlamydia-specific were identified. Additionally, 33 cases of possible gene loss or lateral gene transfer were also detected. Conclusion The identified chlamydiae-lineage specific proteins, many of which are highly conserved, provide novel biomarkers that should prove of much value in the diagnosis of these bacteria and in exploration of their prevalence and diversity. These conserved protein sequences (CPSs also provide novel therapeutic targets for drugs that are specific for these bacteria. Lastly, functional studies on these chlamydiae or chlamydiae subgroup-specific proteins should lead to important insights into lineage-specific adaptations with regards to development, infectivity and pathogenicity.

The β-Hemolysin and Intracellular Survival of Streptococcus agalactiae in Human Macrophages

Science.gov (United States)

Sagar, Anubha; Klemm, Carolin; Hartjes, Lara; Mauerer, Stefanie; van Zandbergen, Ger; Spellerberg, Barbara

2013-01-01

S. agalactiae (group B streptococci, GBS) is a major microbial pathogen in human neonates and causes invasive infections in pregnant women and immunocompromised individuals. The S. agalactiae β-hemolysin is regarded as an important virulence factor for the development of invasive disease. To examine the role of β-hemolysin in the interaction with professional phagocytes, the THP-1 monocytic cell line and human granulocytes were infected with a serotype Ia S. agalactiae wild type strain and its isogenic nonhemolytic mutant. We could show that the nonhemolytic mutants were able to survive in significantly higher numbers than the hemolytic wild type strain, in THP-1 macrophage-like cells and in assays with human granulocytes. Intracellular bacterial multiplication, however, could not be observed. The hemolytic wild type strain stimulated a significantly higher release of Tumor Necrosis Factor-α than the nonhemolytic mutant in THP-1 cells, while similar levels of the chemokine Interleukin-8 were induced. In order to investigate bacterial mediators of IL-8 release in this setting, purified cell wall preparations from both strains were tested and found to exert a potent proinflammatory stimulus on THP-1 cells. In conclusion, our results indicate that the β-hemolysin has a strong influence on the intracellular survival of S. agalactiae and that a tightly controlled regulation of β-hemolysin expression is required for the successful establishment of S. agalactiae in different host niches. PMID:23593170

The β-hemolysin and intracellular survival of Streptococcus agalactiae in human macrophages.

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Anubha Sagar

Full Text Available S. agalactiae (group B streptococci, GBS is a major microbial pathogen in human neonates and causes invasive infections in pregnant women and immunocompromised individuals. The S. agalactiae β-hemolysin is regarded as an important virulence factor for the development of invasive disease. To examine the role of β-hemolysin in the interaction with professional phagocytes, the THP-1 monocytic cell line and human granulocytes were infected with a serotype Ia S. agalactiae wild type strain and its isogenic nonhemolytic mutant. We could show that the nonhemolytic mutants were able to survive in significantly higher numbers than the hemolytic wild type strain, in THP-1 macrophage-like cells and in assays with human granulocytes. Intracellular bacterial multiplication, however, could not be observed. The hemolytic wild type strain stimulated a significantly higher release of Tumor Necrosis Factor-α than the nonhemolytic mutant in THP-1 cells, while similar levels of the chemokine Interleukin-8 were induced. In order to investigate bacterial mediators of IL-8 release in this setting, purified cell wall preparations from both strains were tested and found to exert a potent proinflammatory stimulus on THP-1 cells. In conclusion, our results indicate that the β-hemolysin has a strong influence on the intracellular survival of S. agalactiae and that a tightly controlled regulation of β-hemolysin expression is required for the successful establishment of S. agalactiae in different host niches.

Diversification and Distribution of Ruminant Chlamydia abortus Clones Assessed by MLST and MLVA

OpenAIRE

Siarkou, Victoria I.; Vorimore, Fabien; Vicari, Nadia; Magnino, Simone; Rodolakis, Annie; Pannekoek, Yvonne; Sachse, Konrad; Longbottom, David; Laroucau, Karine

2015-01-01

Chlamydia abortus, an obligate intracellular bacterium, is the most common infectious cause of abortion in small ruminants worldwide and has zoonotic potential. We applied multilocus sequence typing (MLST) together with multiple-locus variable-number tandem repeat analysis (MLVA) to genotype 94 ruminant C. abortus strains, field isolates and samples collected from 1950 to 2011 in diverse geographic locations, with the aim of delineating C. abortus lineages and clones. MLST revealed the previo...

Manipulation of Host Cholesterol by Obligate Intracellular Bacteria

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Dhritiman Samanta

2017-05-01

Full Text Available Cholesterol is a multifunctional lipid that plays important metabolic and structural roles in the eukaryotic cell. Despite having diverse lifestyles, the obligate intracellular bacterial pathogens Chlamydia, Coxiella, Anaplasma, Ehrlichia, and Rickettsia all target cholesterol during host cell colonization as a potential source of membrane, as well as a means to manipulate host cell signaling and trafficking. To promote host cell entry, these pathogens utilize cholesterol-rich microdomains known as lipid rafts, which serve as organizational and functional platforms for host signaling pathways involved in phagocytosis. Once a pathogen gains entrance to the intracellular space, it can manipulate host cholesterol trafficking pathways to access nutrient-rich vesicles or acquire membrane components for the bacteria or bacteria-containing vacuole. To acquire cholesterol, these pathogens specifically target host cholesterol metabolism, uptake, efflux, and storage. In this review, we examine the strategies obligate intracellular bacterial pathogens employ to manipulate cholesterol during host cell colonization. Understanding how obligate intracellular pathogens target and use host cholesterol provides critical insight into the host-pathogen relationship.

MicroRNA-125b-5p suppresses Brucella abortus intracellular survival via control of A20 expression.

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Liu, Ning; Wang, Lin; Sun, Changjiang; Yang, Li; Sun, Wanchun; Peng, Qisheng

2016-07-29

Brucella may establish chronic infection by regulating the expression of miRNAs. However, the role of miRNAs in modulating the intracellular growth of Brucella remains unclear. In this study, we show that Brucella. abortus infection leads to downregulation of miR-125b-5p in macrophages. We establish that miR-125b-5p targets A20, an inhibitor of the NF-kB activation. Additionally, expression of miR-125b-5p decreases A20 expression in B. abortus-infected macrophages and leads to NF-kB activation and increased production of TNFα. Furthermore, B. abortus survival is attenuated in the presence of miR-125b-5p. These results uncover a role for miR-125b-5p in the regulation of B. abortus intracellular survival via the control of A20 expression.

Resolution of Chlamydia trachomatis Infection Is Associated with a Distinct T Cell Response Profile

OpenAIRE

Picard, Michele D.; Bodmer, Jean-Luc; Gierahn, Todd M.; Lee, Alexander; Price, Jessica; Cohane, Kenya; Clemens, Veronica; DeVault, Victoria L.; Gurok, Galina; Kohberger, Robert; Higgins, Darren E.; Siber, George R.; Flechtner, Jessica Baker; Geisler, William M.

2015-01-01

Chlamydia trachomatis is the causative agent of the most frequently reported bacterial sexually transmitted infection, the total burden of which is underestimated due to the asymptomatic nature of the infection. Untreated C. trachomatis infections can cause significant morbidities, including pelvic inflammatory disease and tubal factor infertility (TFI). The human immune response against C. trachomatis, an obligate intracellular bacterium, is poorly characterized but is thought to rely on cel...

Chlamydia control in Europe: literature review

DEFF Research Database (Denmark)

Low, N; S, Redmond; Alexander, K

Executive summary The literature reviews in this report bring together published evidence about the prevalence and reproductive tract complications of chlamydia infection, and about the effectiveness and cost-effectiveness of chlamydia screening interventions. Population prevalence of chlamydia...... in EU/EEA Member States • Ten EU/EEA Member States have conducted population-based cross-sectional surveys to measure the prevalence of chlamydia infection in a nationally representative sample of the population or in a subnational sample of the population. Fourteen EU/EEA Member States have conducted...... cross-sectional surveys using non-population-based sampling methods. Three EU/EEA Member States have no studies estimating chlamydia positivity or prevalence. • Estimates of chlamydia prevalence in population-based studies varied by country, sex, age group, national or sub-national coverage...

Functional and biochemical analysis of Chlamydia trachomatis MurC, an enzyme displaying UDP-N-acetylmuramate:amino acid ligase activity.

Science.gov (United States)

Hesse, Lars; Bostock, Julieanne; Dementin, Sebastien; Blanot, Didier; Mengin-Lecreulx, Dominique; Chopra, Ian

2003-11-01

Chlamydiae are unusual obligate intracellular bacteria that cause serious infections in humans. Chlamydiae contain genes that appear to encode products with peptidoglycan biosynthetic activity. The organisms are also susceptible to antibiotics that inhibit peptidoglycan synthesis. However, chlamydiae do not synthesize detectable peptidoglycan. The paradox created by these observations is known as the chlamydial anomaly. The MurC enzyme of chlamydiae, which is synthesized as a bifunctional MurC-Ddl product, is expected to possess UDP-N-acetylmuramate (UDP-MurNAc):L-alanine ligase activity. In this paper we demonstrate that the MurC domain of the Chlamydia trachomatis bifunctional protein is functionally expressed in Escherichia coli, since it complements a conditional lethal E. coli mutant possessing a temperature-sensitive lesion in MurC. The recombinant MurC domain was overexpressed in and purified from E. coli. It displayed in vitro ATP-dependent UDP-MurNAc:L-alanine ligase activity, with a pH optimum of 8.0 and dependence upon magnesium ions (optimum concentration, 20 mM). Its substrate specificity was studied with three amino acids (L-alanine, L-serine, and glycine); comparable Vmax/Km values were obtained. Our results are consistent with the synthesis of a muramic acid-containing polymer in chlamydiae with UDP-MurNAc-pentapeptide as a precursor molecule. However, due to the lack of specificity of MurC activity in vitro, it is not obvious which amino acid is present in the first position of the pentapeptide.

Chlamydia and Women

Centers for Disease Control (CDC) Podcasts

2009-04-02

This women's health podcast focuses on chlamydia, its severe health consequences for women if left untreated, and the importance of annual chlamydia screening.  Created: 4/2/2009 by Office of Women’s Health (OWH) and National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention (NCHHSTP).   Date Released: 4/2/2009.

Chlamydia psittaci en aves en cautiverio del aquarium de Valencia, Venezuela | Chlamydia psittaci in captive birds of the aquarium of Valencia, Venezuela

Directory of Open Access Journals (Sweden)

Carlos Rodríguez-Leo

2017-11-01

Full Text Available Chlamydia psittaci (Cp is an obligate intracellular bacterium, capable of invading birds and mammals. The prevalence of Cp in adult free-living birds is less than 5%, however in captivity the frequency is very variable (5 - 90%. Cp infections represent a health problem for birds living in captive centers, since in some cases it can be fatal thus generating more concern in threatened species. Therefore, the purpose of this study was the detection of Cp through the nested PCR in birds in captivity and its association to some specific taxonomic order. During 2015-2016, 44 cloacal swabs from six orders of birds were collected from the Valencia Aquarium (VA. The frequency of positives was as high as 77.3% and there was no association between the presence of Cp and a specific bird order. The results were associated with overcrowding conditions in which birds survive, absence of timely diagnosis of Cp in birds entering the VA and possible elevated levels of avian stress. It was confirmed that the state of captivity favors infection by Cp. These results demonstrate the need to promote the adaptation of conditions in captive bird habitats and the timely detection of Cp through molecular methods, mainly for spaces that act as centers for reception of specimens from confiscation, whose goal be their reintroduction to their natural habitat, as part of environmental conservation programs.

Chlamydia trachomatis responds to heat shock, penicillin induced persistence, and IFN-gamma persistence by altering levels of the extracytoplasmic stress response protease HtrA

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Mathews Sarah A

2008-11-01

Full Text Available Abstract Background Chlamydia trachomatis, an obligate intracellular human pathogen, is the most prevalent bacterial sexually transmitted infection worldwide and a leading cause of preventable blindness. HtrA is a virulence and stress response periplasmic serine protease and molecular chaperone found in many bacteria. Recombinant purified C. trachomatis HtrA has been previously shown to have both activities. This investigation examined the physiological role of Chlamydia trachomatis HtrA. Results The Chlamydia trachomatis htrA gene complemented the lethal high temperature phenotype of Escherichia coli htrA- (>42°C. HtrA levels were detected to increase by western blot and immunofluorescence during Chlamydia heat shock experiments. Confocal laser scanning microscopy revealed a likely periplasmic localisation of HtrA. During penicillin induced persistence of Chlamydia trachomatis, HtrA levels (as a ratio of LPS were initially less than control acute cultures (20 h post infection but increased to more than acute cultures at 44 h post infection. This was unlike IFN-γ persistence where lower levels of HtrA were observed, suggesting Chlamydia trachomatis IFN-γ persistence does not involve a broad stress response. Conclusion The heterologous heat shock protection for Escherichia coli, and increased HtrA during cell wall disruption via penicillin and heat shock, indicates an important role for HtrA during high protein stress conditions for Chlamydia trachomatis.

Chlamydia trachomatis in non-specific urethritis.

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Terho, P

1978-01-01

Chlamydia trachomatis was isolated from 58.5% of 159 patients with non-specific urethritis (NSU) using irradiated McCoy cell cultures. Patients with persistent Chlamydia-positive NSU remained Chlamydia-positive each time they were examined before treatment and patients with Chlamydia-negative NSU remained Chlamydia-negative during the course of the illness. Neither the duration of symptoms of urethritis nor a history of previous urethritis affected the chlamydial isolation rate significantly. Of 40 patients with severe discharge 30 (75%) harboured C. trachomatis. One-third of the Chlamydia-positive patients had a severe urethral discharge, while this was present in only 15% of Chlamydia-negative patients. Complications--such as conjunctivitis, arthritis, and epididymitis--were more severe in men with Chlamdia-positive NSU than in those with Chlamydia-negative NSU. Of 64 men matched for sexual promiscuity but without urethritis, none harboured C. trachomatis in his urethra. This differs significantly (P less than 0.001) when compared with patients with NSU. C. trachomatis was isolated from the urogenital tract in 24 (42%) out of 57 female sexual contacts of patients with NSU. The presence of C. trachomatis in the women correlated significantly (P less than 0.001) with the isolation of the agent from their male contacts. These findings give further evidence for the aetiological role of C. trachomatis in non-specific urethritis and its sexual transmission. PMID:678958

Intracellular survival of Staphylococcus aureus during persistent infection in the insect Tenebrio molitor.

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McGonigle, John E; Purves, Joanne; Rolff, Jens

2016-06-01

Survival of bacteria within host cells and tissues presents a challenge to the immune systems of higher organisms. Escape from phagocytic immune cells compounds this issue, as immune cells become potential vehicles for pathogen dissemination. However, the duration of persistence within phagocytes and its contribution to pathogen load has yet to be determined. We investigate the immunological significance of intracellular persistence within the insect model Tenebrio molitor, assessing the extent, duration and location of bacterial recovery during a persistent infection. Relative abundance of Staphylococcus aureus in both intracellular and extracellular fractions was determined over 21 days, and live S. aureus were successfully recovered from both the hemolymph and within phagocytic immune cells across the entire time course. The proportion of bacteria recovered from within phagocytes also increased over time. Our results show that to accurately estimate pathogen load it is vital to account for bacteria persisting within immune cells. Copyright © 2016 Elsevier Ltd. All rights reserved.

Penicillin G-Induced Chlamydial Stress Response in a Porcine Strain of Chlamydia pecorum

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Cory Ann Leonard

2016-01-01

Full Text Available Chlamydia pecorum causes asymptomatic infection and pathology in ruminants, pigs, and koalas. We characterized the antichlamydial effect of the beta lactam penicillin G on Chlamydia pecorum strain 1710S (porcine abortion isolate. Penicillin-exposed and mock-exposed infected host cells showed equivalent inclusions numbers. Penicillin-exposed inclusions contained aberrant bacterial forms and exhibited reduced infectivity, while mock-exposed inclusions contained normal bacterial forms and exhibited robust infectivity. Infectious bacteria production increased upon discontinuation of penicillin exposure, compared to continued exposure. Chlamydia-induced cell death occurred in mock-exposed controls; cell survival was improved in penicillin-exposed infected groups. Similar results were obtained both in the presence and in the absence of the eukaryotic protein translation inhibitor cycloheximide and at different times of initiation of penicillin exposure. These data demonstrate that penicillin G induces the chlamydial stress response (persistence and is not bactericidal, for this chlamydial species/strain in vitro, regardless of host cell de novo protein synthesis.

Ehrlichia chaffeensis TRP120 Activates Canonical Notch Signaling To Downregulate TLR2/4 Expression and Promote Intracellular Survival

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Taslima T. Lina

2016-07-01

Full Text Available Ehrlichia chaffeensis preferentially targets mononuclear phagocytes and survives through a strategy of subverting innate immune defenses, but the mechanisms are unknown. We have shown E. chaffeensis type 1 secreted tandem repeat protein (TRP effectors are involved in diverse molecular pathogen-host interactions, such as the TRP120 interaction with the Notch receptor-cleaving metalloprotease ADAM17. In the present study, we demonstrate E. chaffeensis, via the TRP120 effector, activates the canonical Notch signaling pathway to promote intracellular survival. We found that nuclear translocation of the transcriptionally active Notch intracellular domain (NICD occurs in response to E. chaffeensis or recombinant TRP120, resulting in upregulation of Notch signaling pathway components and target genes notch1, adam17, hes, and hey. Significant differences in canonical Notch signaling gene expression levels (>40% were observed during early and late stages of infection, indicating activation of the Notch pathway. We linked Notch pathway activation specifically to the TRP120 effector, which directly interacts with the Notch metalloprotease ADAM17. Using pharmacological inhibitors and small interfering RNAs (siRNAs against γ-secretase enzyme, Notch transcription factor complex, Notch1, and ADAM17, we demonstrated that Notch signaling is required for ehrlichial survival. We studied the downstream effects and found that E. chaffeensis TRP120-mediated activation of the Notch pathway causes inhibition of the extracellular signal-regulated kinase 1/2 (ERK1/2 and p38 mitogen-activated protein kinase (MAPK pathways required for PU.1 and subsequent Toll-like receptor 2/4 (TLR2/4 expression. This investigation reveals a novel mechanism whereby E. chaffeensis exploits the Notch pathway to evade the host innate immune response for intracellular survival.

The Essential Role of Cholesterol Metabolism in the Intracellular Survival of Mycobacterium leprae Is Not Coupled to Central Carbon Metabolism and Energy Production.

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Marques, Maria Angela M; Berrêdo-Pinho, Marcia; Rosa, Thabatta L S A; Pujari, Venugopal; Lemes, Robertha M R; Lery, Leticia M S; Silva, Carlos Adriano M; Guimarães, Ana Carolina R; Atella, Georgia C; Wheat, William H; Brennan, Patrick J; Crick, Dean C; Belisle, John T; Pessolani, Maria Cristina V

2015-12-01

Mycobacterium leprae induces the formation of lipid droplets, which are recruited to pathogen-containing phagosomes in infected macrophages and Schwann cells. Cholesterol is among the lipids with increased abundance in M. leprae-infected cells, and intracellular survival relies on cholesterol accumulation. The present study investigated the capacity of M. leprae to acquire and metabolize cholesterol. In silico analyses showed that oxidation of cholesterol to cholest-4-en-3-one (cholestenone), the first step of cholesterol degradation catalyzed by the enzyme 3β-hydroxysteroid dehydrogenase (3β-HSD), is apparently the only portion of the cholesterol catabolic pathway seen in Mycobacterium tuberculosis preserved by M. leprae. Incubation of bacteria with radiolabeled cholesterol confirmed the in silico predictions. Radiorespirometry and lipid analyses performed after incubating M. leprae with [4-(14)C]cholesterol or [26-(14)C]cholesterol showed the inability of this pathogen to metabolize the sterol rings or the side chain of cholesterol as a source of energy and carbon. However, the bacteria avidly incorporated cholesterol and, as expected, converted it to cholestenone both in vitro and in vivo. Our data indicate that M. leprae has lost the capacity to degrade and utilize cholesterol as a nutritional source but retains the enzyme responsible for its oxidation to cholestenone. Thus, the essential role of cholesterol metabolism in the intracellular survival of M. leprae is uncoupled from central carbon metabolism and energy production. Further elucidation of cholesterol metabolism in the host cell during M. leprae infection will establish the mechanism by which this lipid supports M. leprae intracellular survival and will open new avenues for novel leprosy therapies. Our study focused on the obligate intracellular pathogen Mycobacterium leprae and its capacity to metabolize cholesterol. The data make an important contribution for those interested in understanding the

Chlamydia Test: MedlinePlus Lab Test Information

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... page: https://medlineplus.gov/labtests/chlamydiatest.html Chlamydia Test To use the sharing features on this page, please enable JavaScript. What is a Chlamydia Test? Chlamydia is one of the most common sexually ...

Animal models for studying female genital tract infection with Chlamydia trachomatis.

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De Clercq, Evelien; Kalmar, Isabelle; Vanrompay, Daisy

2013-09-01

Chlamydia trachomatis is a Gram-negative obligate intracellular bacterial pathogen. It is the leading cause of bacterial sexually transmitted disease in the world, with more than 100 million new cases of genital tract infections with C. trachomatis occurring each year. Animal models are indispensable for the study of C. trachomatis infections and the development and evaluation of candidate vaccines. In this paper, the most commonly used animal models to study female genital tract infections with C. trachomatis will be reviewed, namely, the mouse, guinea pig, and nonhuman primate models. Additionally, we will focus on the more recently developed pig model.

Chlamydia

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In men, chlamydia may cause symptoms similar to gonorrhea . Symptoms may include: Burning feeling during urination Discharge ... of sexually transmitted infection (STIs). Common STIs are gonorrhea, HIV, syphilis, hepatitis, and herpes . Even if you ...

Detection of Chlamydia in postmortal formalin-fixed tissue

DEFF Research Database (Denmark)

Lundemose, AG; Lundemose, JB; Birkelund, Svend

1989-01-01

A procedure to detect Chlamydia in postmortal formalin-fixed tissue is described. Monoclonal antibodies against a genus specific chlamydia epitope were used in immunofluorescence to detect chlamydia inclusions in formalin-fixed tissue sections. Lung sections from chlamydia-infected mice were....... Background and non-specific fluorescence were reduced by treating the tissue sections with trypsin, rabbit serum and Evans blue counterstain. Besides giving an exact diagnosis at autopsy, the method provides the possibility of determining the occurrence of chlamydia infections in various tissues, based...

Analysis of MreB interactors in Chlamydia reveals a RodZ homolog but fails to detect an interaction with MraY.

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Ouellette, Scot P; Rueden, Kelsey J; Gauliard, Emilie; Persons, Logan; de Boer, Piet A; Ladant, Daniel

2014-01-01

Chlamydia is an obligate intracellular bacterial pathogen that has significantly reduced its genome in adapting to the intracellular environment. One class of genes for which the bacterium has few annotated examples is cell division, and Chlamydia lacks FtsZ, a central coordinator of the division apparatus. We have previously implicated MreB as a potential substitute for FtsZ in Chlamydia (Ouellette et al., 2012). Thus, to identify new chlamydial cell division components, we searched for proteins that interacted with MreB. We performed a small-scale screen using a Gateway® compatible version of the Bacterial Adenylate Cyclase Two Hybrid (BACTH) system, BACTHGW, to detect proteins interacting with chlamydial MreB and identified a RodZ (YfgA) homolog. The chlamydial RodZ aligns well with the cytoplasmic domain of E. coli RodZ but lacks the periplasmic domain that is dispensable for rod cell shape maintenance in E. coli. The expression pattern of yfgA/rodZ was similar to that of mreB and ftsI, suggesting that these genes may operate in a common functional pathway. The chlamydial RodZ correctly localized to the membrane of E. coli but was unable to complement an E. coli rodZ mutant strain, likely because of the inability of chlamydial RodZ to interact with the native E. coli MreB. Finally, we also tested whether chlamydial MreB could interact with MraY, as suggested by Gaballah et al. (2011). However, we did not detect an interaction between these proteins even when using an implementation of the BACTH system to allow native orientation of the N- and C-termini of MraY in the periplasm. Thus, further work will be needed to establish this proposed interaction. In sum, we have added to the repertoire of potential cell division proteins of Chlamydia.

Analysis of MreB interactors in Chlamydia reveals a RodZ homolog but fails to detect an interaction with MraY

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Scot P Ouellette

2014-06-01

Full Text Available Chlamydia is an obligate intracellular bacterial pathogen that has significantly reduced its genome in adapting to the intracellular environment. One class of genes for which the bacterium has few annotated examples is cell division, and Chlamydia lacks FtsZ, a central coordinator of the division apparatus. We have previously implicated MreB as a potential substitute for FtsZ in Chlamydia (Ouellette et al., 2012. Thus, to identify new chlamydial cell division components, we searched for proteins that interacted with MreB. We performed a small-scale screen using a Gateway® compatible version of the Bacterial Adenylate Cyclase Two Hybrid (BACTH system, BACTHGW, to detect proteins interacting with chlamydial MreB and identified a RodZ (YfgA homolog. The chlamydial RodZ aligns well with the cytoplasmic domain of E. coli RodZ but lacks the periplasmic domain that is dispensable for rod cell shape maintenance in E. coli. The expression pattern of yfgA/rodZ was similar to that of mreB and ftsI, suggesting that these genes may operate in a common functional pathway. The chlamydial RodZ correctly localized to the membrane of E. coli but was unable to complement an E. coli rodZ mutant strain, likely because of the inability of chlamydial RodZ to interact with the native E. coli MreB. Finally, we also tested whether chlamydial MreB could interact with MraY, as suggested by Gaballah et al. (2011. However, we did not detect an interaction between these proteins even when using an implementation of the BACTH system to allow native orientation of the N- and C-termini of MraY in the periplasm. Thus, further work will be needed to establish this proposed interaction. In sum, we have added to the repertoire of potential cell division proteins of Chlamydia.

Identification, characterisation and expression analysis of natural killer receptor genes in Chlamydia pecorum infected koalas (Phascolarctos cinereus).

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Morris, Katrina M; Mathew, Marina; Waugh, Courtney; Ujvari, Beata; Timms, Peter; Polkinghorne, Adam; Belov, Katherine

2015-10-15

Koalas (Phascolarctos cinereus), an iconic Australian marsupial, are being heavily impacted by the spread of Chlamydia pecorum, an obligate intracellular bacterial pathogen. Koalas vary in their response to this pathogen, with some showing no symptoms, while others suffer severe symptoms leading to infertility, blindness or death. Little is known about the pathology of this disease and the immune response against it in this host. Studies have demonstrated that natural killer (NK) cells, key components of the innate immune system, are involved in the immune response to chlamydial infections in humans. These cells can directly lyse cells infected by intracellular pathogens and their ability to recognise these infected cells is mediated through NK receptors on their surface. These are encoded in two regions of the genome, the leukocyte receptor complex (LRC) and the natural killer complex (NKC). These two families evolve rapidly and different repertoires of genes, which have evolved by gene duplication, are seen in different species. In this study we aimed to characterise genes belonging to the NK receptor clusters in the koala by searching available koala transcriptomes using a combination of search methods. We developed a qPCR assay to quantify relative expression of four genes, two encoded within the NK receptor cluster (CLEC1B, CLEC4E) and two known to play a role in NK response to Chalmydia in humans (NCR3, PRF1). We found that the NK receptor repertoire of the koala closely resembles that of the Tasmanian devil, with minimal genes in the NKC, but with lineage specific expansions in the LRC. Additional genes important for NK cell activity, NCR3 and PRF1, were also identified and characterised. In a preliminary study to investigate whether these genes are involved in the koala immune response to infection by its chlamydial pathogen, C. pecorum, we investigated the expression of four genes in koalas with active chlamydia infection, those with past infection and

T3SS effector VopL inhibits the host ROS response, promoting the intracellular survival of Vibrio parahaemolyticus.

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Marcela de Souza Santos

2017-06-01

Full Text Available The production of antimicrobial reactive oxygen species by the nicotinamide dinucleotide phosphate (NADPH oxidase complex is an important mechanism for control of invading pathogens. Herein, we show that the gastrointestinal pathogen Vibrio parahaemolyticus counteracts reactive oxygen species (ROS production using the Type III Secretion System 2 (T3SS2 effector VopL. In the absence of VopL, intracellular V. parahaemolyticus undergoes ROS-dependent filamentation, with concurrent limited growth. During infection, VopL assembles actin into non-functional filaments resulting in a dysfunctional actin cytoskeleton that can no longer mediate the assembly of the NADPH oxidase at the cell membrane, thereby limiting ROS production. This is the first example of how a T3SS2 effector contributes to the intracellular survival of V. parahaemolyticus, supporting the establishment of a protective intracellular replicative niche.

Pathogen–host reorganization during Chlamydia invasion revealed by cryo-electron tomography

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Nans, Andrea; Saibil, Helen R; Hayward, Richard D

2014-01-01

Invasion of host cells is a key early event during bacterial infection, but the underlying pathogen–host interactions are yet to be fully visualized in three-dimensional detail. We have captured snapshots of the early stages of bacterial-mediated endocytosis in situ by exploiting the small size of chlamydial elementary bodies (EBs) for whole-cell cryo-electron tomography. Chlamydiae are obligate intracellular bacteria that infect eukaryotic cells and cause sexually transmitted infections and trachoma, the leading cause of preventable blindness. We demonstrate that Chlamydia trachomatis LGV2 EBs are intrinsically polarized. One pole is characterized by a tubular inner membrane invagination, while the other exhibits asymmetric periplasmic expansion to accommodate an array of type III secretion systems (T3SSs). Strikingly, EBs orient with their T3SS-containing pole facing target cells, enabling the T3SSs to directly contact the cellular plasma membrane. This contact induces enveloping macropinosomes, actin-rich filopodia and phagocytic cups to zipper tightly around the internalizing bacteria. Once encapsulated into tight early vacuoles, EB polarity and the T3SSs are lost. Our findings reveal previously undescribed structural transitions in both pathogen and host during the initial steps of chlamydial invasion. PMID:24809274

Inhibition of Fusion of Chlamydia trachomatis Inclusions at 32°C Correlates with Restricted Export of IncA

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Fields, K. A.; Fischer, E.; Hackstadt, T.

2002-01-01

Chlamydia trachomatis is an obligate intracellular bacterium that develops within a parasitophorous vacuole termed an inclusion. The inclusion is nonfusogenic with lysosomes but intercepts lipids from a host cell exocytic pathway. Initiation of chlamydial development is concurrent with modification of the inclusion membrane by a set of C. trachomatis-encoded proteins collectively designated Incs. One of these Incs, IncA, is functionally associated with the homotypic fusion of inclusions. Incl...

STING-Dependent 2'-5' Oligoadenylate Synthetase-Like Production Is Required for Intracellular Mycobacterium leprae Survival.

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de Toledo-Pinto, Thiago Gomes; Ferreira, Anna Beatriz Robottom; Ribeiro-Alves, Marcelo; Rodrigues, Luciana Silva; Batista-Silva, Leonardo Ribeiro; Silva, Bruno Jorge de Andrade; Lemes, Robertha Mariana Rodrigues; Martinez, Alejandra Nóbrega; Sandoval, Felipe Galvan; Alvarado-Arnez, Lucia Elena; Rosa, Patrícia Sammarco; Shannon, Edward Joseph; Pessolani, Maria Cristina Vidal; Pinheiro, Roberta Olmo; Antunes, Sérgio Luís Gomes; Sarno, Euzenir Nunes; Lara, Flávio Alves; Williams, Diana Lynn; Ozório Moraes, Milton

2016-07-15

Cytosolic detection of nucleic acids elicits a type I interferon (IFN) response and plays a critical role in host defense against intracellular pathogens. Herein, a global gene expression profile of Mycobacterium leprae-infected primary human Schwann cells identified the genes differentially expressed in the type I IFN pathway. Among them, the gene encoding 2'-5' oligoadenylate synthetase-like (OASL) underwent the greatest upregulation and was also shown to be upregulated in M. leprae-infected human macrophage cell lineages, primary monocytes, and skin lesion specimens from patients with a disseminated form of leprosy. OASL knock down was associated with decreased viability of M. leprae that was concomitant with upregulation of either antimicrobial peptide expression or autophagy levels. Downregulation of MCP-1/CCL2 release was also observed during OASL knock down. M. leprae-mediated OASL expression was dependent on cytosolic DNA sensing mediated by stimulator of IFN genes signaling. The addition of M. leprae DNA enhanced nonpathogenic Mycobacterium bovis bacillus Calmette-Guerin intracellular survival, downregulated antimicrobial peptide expression, and increased MCP-1/CCL2 secretion. Thus, our data uncover a promycobacterial role for OASL during M. leprae infection that directs the host immune response toward a niche that permits survival of the pathogen. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

Chlamydia trachomatis antigens in enteroendocrine cells and macrophages of the small bowel in patients with severe irritable bowel syndrome

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Sandström Gunnar

2010-02-01

Full Text Available Abstract Background Inflammation and immune activation have repeatedly been suggested as pathogentic factors in irritable bowel syndrome (IBS. The driving force for immune activation in IBS remains unknown. The aim of our study was to find out if the obligate intracellular pathogen Chlamydia could be involved in the pathogenesis of IBS. Methods We studied 65 patients (61 females with IBS and 42 (29 females healthy controls in which IBS had been excluded. Full thickness biopsies from the jejunum and mucosa biopsies from the duodenum and the jejunum were stained with a monoclonal antibody to Chlamydia lipopolysaccharide (LPS and species-specific monoclonal antibodies to C. trachomatis and C. pneumoniae. We used polyclonal antibodies to chromogranin A, CD68, CD11c, and CD117 to identify enteroendocrine cells, macrophages, dendritic, and mast cells, respectively. Results Chlamydia LPS was present in 89% of patients with IBS, but in only 14% of healthy controls (p C. trachomatis major outer membrane protein (MOMP. Staining for C. pneumoniae was negative in both patients and controls. Chlamydia LPS was detected in enteroendocrine cells of the mucosa in 90% of positive biopsies and in subepithelial macrophages in 69% of biopsies. Biopsies taken at different time points in 19 patients revealed persistence of Chlamydia LPS up to 11 years. The odds ratio for the association of Chlamydia LPS with presence of IBS (43.1; 95% CI: 13.2-140.7 is much higher than any previously described pathogenetic marker in IBS. Conclusions We found C. trachomatis antigens in enteroendocrine cells and macrophages in the small bowel mucosa of patients with IBS. Further studies are required to clarify if the presence of such antigens has a role in the pathogenesis of IBS.

Comparison between ICT and PCR for diagnosis of Chlamydia trachomatis.

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Khan, E R; Hossain, M A; Paul, S K; Mahmud, C; Hasan, M M; Rahman, M M; Nahar, K; Kubayashi, N

2012-04-01

Chlamydia trachomatis is an obligate intracellular gram-negative bacterium which is the most prevalent cause of bacterial sexually transmitted infections (STI). The present study was carried to diagnose genital Chlamydia trachomatis infection among women of reproductive age, attending Mymensingh Medical College Hospital, during July 2009 to June 2010 by Immunochromatographic test (ICT) and Polymerase chain reaction (PCR). A total of 70 females were included in this study. Out of 70 cases 56 were symptomatic and 14 asymptomatic. Endocervical swabs were collected from each of the cases and examined by Immunochromatographic test (ICT) for antigen detection and Polymerase chain reaction (PCR) for detection of endogenous plasmid-based nucleic acid. A total 29(41.4%) of the cases were found positive for C. trachomatis either by ICT or PCR. Of the 56 symptomatic cases, 19(33.9%) were found ICT positive and 17(30.4%) were PCR positive. Among 14 asymptomatic females, 2(14.3%) were ICT positive and none were PCR positive. Though PCR is highly sensitive but a total of twelve cases were found ICT positive but PCR negative. It may be due to presence of plasmid deficient strain of C trachomatis which could be amplified by ompA based (Chromosomal gene) multiplex PCR.

Analysis of glycosidases activity in Chlamydia trachomatis L2 serotype

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Dr. Sanjiv Rughooputh

2006-01-01

Full Text Available Chlamydiae are prokaryotic, gram negative, intracellular parasites, causing a number of human diseases with serious sequelae. The exact mechanism of chlamydial attachment and entry into the host cell is still unclear. Chlamydia trachomatis, SA2F (L2 was tested for the activity of glycosidases. Glycosidases are involved in the synthesis and breakdown of cell-wall polysaccharides, and have a pivotal role in attachment to the surface of host cells as well as in the invasion process of other infective agents. For these reasons, glycosidases are likely to provide important information regarding the general behaviour of this bacterium. Ten different glycosides bound to p-nitrophenol (pNP substrate were tested. Assays were performed on lysed and unlysed chlamydial extracts.Our results provided strong evidence for the existence of glycosidase activity in C.trachomatis, strain SA2F peaking at pH 5.0 and pH 7.5-8.0 There was a high enzymatic activity against p-NPa mannopyranoside and p-NP b-N acetylglucosamine with a recovery of 88% suggesting that the enzymes were present on the bacterial surface. Activity against these sugars, which form part of either the extracellular filler or in endoplasmic reticulum may suggest of a possible mechanism of cellular invasion.

Advances in genetic manipulation of obligate intracellular bacterial pathogens

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Paul eBeare

2011-05-01

Full Text Available Infections by obligate intracellular bacterial pathogens result in significant morbidity and mortality worldwide. These bacteria include Chlamydia spp., which causes millions of cases of sexually transmitted disease and blinding trachoma annually, and members of the α-proteobacterial genera Anaplasma, Ehrlichia, Orientia and Rickettsia, agents of serious human illnesses including epidemic typhus. Coxiella burnetii, the agent of human Q fever, has also been considered a prototypical obligate intracellular bacterium, but recent host cell-free (axenic growth has rescued it from obligatism. The historic genetic intractability of obligate intracellular bacteria has severely limited molecular dissection of their unique lifestyles and virulence factors involved in pathogenesis. Host cell restricted growth is a significant barrier to genetic transformation that can make simple procedures for free-living bacteria, such as cloning, exceedingly difficult. Low transformation efficiency requiring long term culture in host cells to expand small transformant populations is another obstacle. Despite numerous technical limitations, the last decade has witnessed significant gains in genetic manipulation of obligate intracellular bacteria including allelic exchange. Continued development of genetic tools should soon enable routine mutation and complementation strategies for virulence factor discovery and stimulate renewed interest in these refractory pathogens. In this review, we discuss the technical challenges associated with genetic transformation of obligate intracellular bacteria and highlight advances made with individual genera.

Uptake of biotin by Chlamydia Spp. through the use of a bacterial transporter (BioY and a host-cell transporter (SMVT.

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Derek J Fisher

Full Text Available Chlamydia spp. are obligate intracellular Gram-negative bacterial pathogens that cause disease in humans and animals. Minor variations in metabolic capacity between species have been causally linked to host and tissue tropisms. Analysis of the highly conserved genomes of Chlamydia spp. reveals divergence in the metabolism of the essential vitamin biotin with genes for either synthesis (bioF_2ADB and/or transport (bioY. Streptavidin blotting confirmed the presence of a single biotinylated protein in Chlamydia. As a first step in unraveling the need for divergent biotin acquisition strategies, we examined BioY (CTL0613 from C. trachomatis 434/Bu which is annotated as an S component of the type II energy coupling-factor transporters (ECF. Type II ECFs are typically composed of a transport specific component (S and a chromosomally unlinked energy module (AT. Intriguingly, Chlamydia lack recognizable AT modules. Using (3H-biotin and recombinant E. coli expressing CTL0613, we demonstrated that biotin was transported with high affinity (a property of Type II ECFs previously shown to require an AT module and capacity (apparent K(m of 3.35 nM and V(max of 55.1 pmol×min(-1×mg(-1. Since Chlamydia reside in a host derived membrane vacuole, termed an inclusion, we also sought a mechanism for transport of biotin from the cell cytoplasm into the inclusion vacuole. Immunofluorescence microscopy revealed that the mammalian sodium multivitamin transporter (SMVT, which transports lipoic acid, biotin, and pantothenic acid into cells, localizes to the inclusion. Since Chlamydia also are auxotrophic for lipoic and pantothenic acids, SMVT may be subverted by Chlamydia to move multiple essential compounds into the inclusion where BioY and another transporter(s would be present to facilitate transport into the bacterium. Collectively, our data validates the first BioY from a pathogenic organism and describes a two-step mechanism by which Chlamydia transport biotin

Uptake of Biotin by Chlamydia Spp. through the Use of a Bacterial Transporter (BioY) and a Host-Cell Transporter (SMVT)

Science.gov (United States)

Fisher, Derek J.; Fernández, Reinaldo E.; Adams, Nancy E.; Maurelli, Anthony T.

2012-01-01

Chlamydia spp. are obligate intracellular Gram-negative bacterial pathogens that cause disease in humans and animals. Minor variations in metabolic capacity between species have been causally linked to host and tissue tropisms. Analysis of the highly conserved genomes of Chlamydia spp. reveals divergence in the metabolism of the essential vitamin biotin with genes for either synthesis (bioF_2ADB) and/or transport (bioY). Streptavidin blotting confirmed the presence of a single biotinylated protein in Chlamydia. As a first step in unraveling the need for divergent biotin acquisition strategies, we examined BioY (CTL0613) from C. trachomatis 434/Bu which is annotated as an S component of the type II energy coupling-factor transporters (ECF). Type II ECFs are typically composed of a transport specific component (S) and a chromosomally unlinked energy module (AT). Intriguingly, Chlamydia lack recognizable AT modules. Using 3H-biotin and recombinant E. coli expressing CTL0613, we demonstrated that biotin was transported with high affinity (a property of Type II ECFs previously shown to require an AT module) and capacity (apparent K(m) of 3.35 nM and V(max) of 55.1 pmol×min−1×mg−1). Since Chlamydia reside in a host derived membrane vacuole, termed an inclusion, we also sought a mechanism for transport of biotin from the cell cytoplasm into the inclusion vacuole. Immunofluorescence microscopy revealed that the mammalian sodium multivitamin transporter (SMVT), which transports lipoic acid, biotin, and pantothenic acid into cells, localizes to the inclusion. Since Chlamydia also are auxotrophic for lipoic and pantothenic acids, SMVT may be subverted by Chlamydia to move multiple essential compounds into the inclusion where BioY and another transporter(s) would be present to facilitate transport into the bacterium. Collectively, our data validates the first BioY from a pathogenic organism and describes a two-step mechanism by which Chlamydia transport biotin from the

Intracellular ice and cell survival in cryo-exposed embryonic axes of recalcitrant seeds of Acer saccharinum: an ultrastructural study of factors affecting cell and ice structures.

Science.gov (United States)

Wesley-Smith, James; Berjak, Patricia; Pammenter, N W; Walters, Christina

2014-03-01

Cryopreservation is the only long-term conservation strategy available for germplasm of recalcitrant-seeded species. Efforts to cryopreserve this form of germplasm are hampered by potentially lethal intracellular freezing events; thus, it is important to understand the relationships among cryo-exposure techniques, water content, structure and survival. Undried embryonic axes of Acer saccharinum and those rapidly dried to two different water contents were cooled at three rates and re-warmed at two rates. Ultrastructural observations were carried out on radicle and shoot tips prepared by freeze-fracture and freeze-substitution to assess immediate (i.e. pre-thaw) responses to cooling treatments. Survival of axes was assessed in vitro. Intracellular ice formation was not necessarily lethal. Embryo cells survived when crystal diameter was between 0·2 and 0·4 µm and fewer than 20 crystals were distributed per μm(2) in the cytoplasm. Ice was not uniformly distributed within the cells. In fully hydrated axes cooled at an intermediate rate, the interiors of many organelles were apparently ice-free; this may have prevented the disruption of vital intracellular machinery. Intracytoplasmic ice formation did not apparently impact the integrity of the plasmalemma. The maximum number of ice crystals was far greater in shoot apices, which were more sensitive than radicles to cryo-exposure. The findings challenge the accepted paradigm that intracellular ice formation is always lethal, as the results show that cells can survive intracellular ice if crystals are small and localized in the cytoplasm. Further understanding of the interactions among water content, cooling rate, cell structure and ice structure is required to optimize cryopreservation treatments without undue reliance on empirical approaches.

The trans-Golgi SNARE syntaxin 10 is required for optimal development of Chlamydia trachomatis

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Andrea L Lucas

2015-09-01

Full Text Available Chlamydia trachomatis, an obligate intracellular pathogen, grows inside of a vacuole, termed the inclusion. Within the inclusion, the organisms differentiate from the infectious elementary body (EB into the reticulate body (RB. The RB communicates with the host cell through the inclusion membrane to obtain the nutrients necessary to divide, thus expanding the chlamydial population. At late time points within the developmental cycle, the RBs respond to unknown molecular signals to redifferentiate into infectious EBs to perpetuate the infection cycle. One strategy for Chlamydia to obtain necessary nutrients and metabolites from the host is to intercept host vesicular trafficking pathways. In this study we demonstrate that a trans-Golgi soluble N-ethylmaleimide–sensitive factor attachment protein (SNARE, syntaxin 10, and/or syntaxin10-associated Golgi elements colocalize with the chlamydial inclusion. We hypothesized that Chlamydia utilizes the molecular machinery of syntaxin 10 at the inclusion membrane to intercept specific vesicular trafficking pathways in order to create and maintain an optimal intra-inclusion environment. To test this hypothesis, we used siRNA knockdown of syntaxin 10 to examine the impact of the loss of syntaxin 10 on chlamydial growth and development. Our results demonstrate that loss of syntaxin 10 leads to defects in normal chlamydial maturation including: variable inclusion size with fewer chlamydial organisms per inclusion, fewer infectious progeny, and delayed or halted RB-EB differentiation. These defects in chlamydial development correlate with an overabundance of NBD-lipid retained by inclusions cultured in syntaxin 10 knockdown cells. Overall, loss of syntaxin 10 at the inclusion membrane negatively affects Chlamydia. Understanding host machinery involved in maintaining an optimal inclusion environment to support chlamydial growth and development is critical towards understanding the molecular signals involved in

21 CFR 866.3120 - Chlamydia serological reagents.

Science.gov (United States)

2010-04-01

... (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3120 Chlamydia... and antisera used in serological tests to identify antibodies to chlamydia in serum. Additionally...

A Functional Core of IncA Is Required for Chlamydia trachomatis Inclusion Fusion.

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Weber, Mary M; Noriea, Nicholas F; Bauler, Laura D; Lam, Jennifer L; Sager, Janet; Wesolowski, Jordan; Paumet, Fabienne; Hackstadt, Ted

2016-04-01

Chlamydia trachomatis is an obligate intracellular pathogen that is the etiological agent of a variety of human diseases, including blinding trachoma and sexually transmitted infections. Chlamydiae replicate within a membrane-bound compartment, termed an inclusion, which they extensively modify by the insertion of type III secreted proteins called Inc proteins. IncA is an inclusion membrane protein that encodes two coiled-coil domains that are homologous to eukaryotic SNARE (soluble N-ethylmaleimide-sensitive factor attachment receptor) motifs. Recent biochemical evidence suggests that a functional core, composed of SNARE-like domain 1 (SLD-1) and part of SNARE-like domain 2 (SLD-2), is required for the characteristic homotypic fusion of C. trachomatis inclusions in multiply infected cells. To verify the importance of IncA in homotypic fusion in Chlamydia, we generated an incA::bla mutant. Insertional inactivation of incA resulted in the formation of nonfusogenic inclusions, a phenotype that was completely rescued by complementation with full-length IncA. Rescue of homotypic inclusion fusion was dependent on the presence of the functional core consisting of SLD-1 and part of SLD-2. Collectively, these results confirm in vitro membrane fusion assays identifying functional domains of IncA and expand the genetic tools available for identification of chlamydia with a method for complementation of site-specific mutants. Chlamydia trachomatis replicates within a parasitophorous vacuole termed an inclusion. The chlamydial inclusions are nonfusogenic with vesicles in the endocytic pathway but, in multiply infected cells, fuse with each other to form a single large inclusion. This homotypic fusion is dependent upon the presence of a chlamydial inclusion membrane-localized protein, IncA. Specificity of membrane fusion in eukaryotic cells is regulated by SNARE (soluble N-ethylmaleimide sensitive factor attachment receptor) proteins on the cytosolic face of vesicles and target

Genital chlamydia trachomatis infection among female ...

African Journals Online (AJOL)

Background: Genital Chlamydia trachomatis infection is a common bacterial sexually transmitted infection worldwide. There is little information about this infection in Nigeria. This study determined the prevalence of genital Chlamydia trachomatis infection among female undergraduates of University of Port Harcourt and ...

Screening on urogenital Chlamydia trachomatis

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Busse, Reinhard

2005-12-01

Full Text Available Introduction: Around 92 million urogenital infections are caused yearly by Chlamydia trachomatis worldwide [1]. The overall incidence of sexually transmitted diseases is increasing, as shown by the increases in the number of reported cases of syphilis and gonorrhea [2]. Chlamydia trachomatis infections are associated with various serious diseases in women, men and newborns, which could be, at least partially, avoided by means of early diagnosis and therapy. The Federal Joint Committee - responsible for decision-making concerning the benefit package of the German Social Health Insurance - has publicly announced the starting of deliberations on the issue of screening for Chlamydia trachomatis. Research Questions: The leading question to be answered is whether screening for Chlamydia trachomatis should be included in the German benefit basket. The aim of this report is to provide a summary of the available evidence concerning the issue of screening for Chlamydia trachomatis. Methods: The summary of published scientific evidence, including HTA reports, systematic reviews, guidelines and primary research is represented. The synthesis follows the structure given by the criteria of Wilson and Jungner [3] for the introduction of screening in a population: relevance of the condition, availability of an adequate test, effectiveness of screening, acceptance of the programme, and economical issues. A literature search was conducted for each aspect of the synthesis and the evidence has been summarised in evidence tables. Results: We identified five HTA reports from three European agencies [4], [5], [6], [7] and one from the USA [8]. In addition, we identified four guidelines from Northamerica [9], [10], [11], [12] and one from Europe [13]. A total of 56 primary research publications were included: relevance of the disease (n=26, availability of test (n=1, effectiveness of screening (n=11, acceptance of the programme (n=11, economical issues (n=7. Discussion

Comparison of the population excess fraction of Chlamydia trachomatis infection on pelvic inflammatory disease at 12-months in the presence and absence of Chlamydia testing and treatment

DEFF Research Database (Denmark)

Davies, Bethan; Turner, Katy M.E.; Leung, Stella

2017-01-01

Background: The impact of Chlamydia trachomatis (chlamydia) control on the incidence of pelvic inflammatory disease (PID) is theoretically limited by the proportion of PID caused by chlamydia. We estimate the population excess fraction (PEF) of treated chlamydia infection on PID at 12-months...... in settings with widespread chlamydia control (testing and treatment) and compare this to the estimated PEF of untreated chlamydia. Methods: We used two large retrospective population-based cohorts of women of reproductive age from settings with widespread chlamydia control to calculate the PEF of treated...... chlamydia on PID at 12-months. We undertook a systematic review to identify further studies that reported the risk of PID in women who were tested for chlamydia (infected and uninfected). We used the same method to calculate the PEF in eligible studies then compared all estimates of PEF. Results...

Chlamydia

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... No single step can protect you from every single type of STI. Can women who have sex with women get chlamydia? Yes. ... Notice Language Assistance Available Accessibility Privacy Policy Disclaimers Freedom of Information Act ... A federal government website managed by the Office on Women's Health in the Office of the Assistant Secretary ...

Chlamydia in canine or feline coronary arteriosclerotic lesions

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Grabarevic Zeljko

2011-09-01

Full Text Available Abstract Background There are numerous reports linking Chlamydia infection to human coronary atherosclerosis. However, there is a lack of data regarding this correlation in dogs and cats, and there are no reports investigating coronary arteriosclerosis and Chlamydia in these species. The aim of the present study was to examine whether there is a correlation between canine and feline spontaneous atherosclerosis or arteriosclerosis and the presence of Chlamydia. Archived histopathological samples of dogs (n = 16 and cats (n = 13 with findings of atherosclerosis or arteriosclerosis in heart tissue were examined for the presence of Chlamydiaceae using real-time PCR, ArrayTube Microarray and immunohistochemistry. Additionally, arteriosclerotic lesions of all cases were histologically classified and graded. Results Both canine atherosclerotic cases, and all 14 canine arteriosclerotic cases were negative for Chlamydia. Only one of the 13 arteriosclerotic feline cases was positive for Chlamydia by real-time PCR, revealing C. abortus by ArrayTube Microarray. To our knowledge, this is the first description of C. abortus in a cat. Overall, the type and grade of canine and feline arteriosclerotic lesions revealed similarities, and were predominantly moderate and hyperplastic. Conclusions These findings suggest that there is no obvious correlation between canine and feline coronary arteriosclerosis and the presence of Chlamydia. In order to draw final conclusions about the correlation between Chlamydia and canine atherosclerosis, examination of more samples is required.

Chlamydia in canine or feline coronary arteriosclerotic lesions.

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Sostaric-Zuckermann, Ivan C; Borel, Nicole; Kaiser, Carmen; Grabarevic, Zeljko; Pospischil, Andreas

2011-09-09

There are numerous reports linking Chlamydia infection to human coronary atherosclerosis. However, there is a lack of data regarding this correlation in dogs and cats, and there are no reports investigating coronary arteriosclerosis and Chlamydia in these species. The aim of the present study was to examine whether there is a correlation between canine and feline spontaneous atherosclerosis or arteriosclerosis and the presence of Chlamydia. Archived histopathological samples of dogs (n = 16) and cats (n = 13) with findings of atherosclerosis or arteriosclerosis in heart tissue were examined for the presence of Chlamydiaceae using real-time PCR, ArrayTube Microarray and immunohistochemistry. Additionally, arteriosclerotic lesions of all cases were histologically classified and graded. Both canine atherosclerotic cases, and all 14 canine arteriosclerotic cases were negative for Chlamydia. Only one of the 13 arteriosclerotic feline cases was positive for Chlamydia by real-time PCR, revealing C. abortus by ArrayTube Microarray. To our knowledge, this is the first description of C. abortus in a cat. Overall, the type and grade of canine and feline arteriosclerotic lesions revealed similarities, and were predominantly moderate and hyperplastic. These findings suggest that there is no obvious correlation between canine and feline coronary arteriosclerosis and the presence of Chlamydia. In order to draw final conclusions about the correlation between Chlamydia and canine atherosclerosis, examination of more samples is required.

Nonactivated titanium-dioxide nanoparticles promote the growth of Chlamydia trachomatis and decrease the antimicrobial activity of silver nanoparticles.

Science.gov (United States)

Bogdanov, A; Janovák, L; Lantos, I; Endrész, V; Sebők, D; Szabó, T; Dékány, I; Deák, J; Rázga, Z; Burián, K; Virok, D P

2017-11-01

Chlamydia trachomatis and herpes simplex virus (HSV) are the most prevalent bacterial and viral sexually transmitted infections. Due to the chronic nature of their infections, they are able to interact with titanium-dioxide (TiO 2 ) nanoparticles (NPs) applied as food additives or drug delivery vehicles. The aim of this study was to describe the interactions of these two prevalent pathogens with the TiO 2 NPs. Chlamydia trachomatis and HSV-2 were treated with nonactivated TiO 2 NPs, silver NPs and silver decorated TiO 2 NPs before infection of HeLa and Vero cells. Their intracellular growth was monitored by quantitative PCR. Unexpectedly, the TiO 2 NPs (100 μg ml -1 ) increased the growth of C. trachomatis by approximately fourfold, while the HSV-2 replication was not affected. Addition of TiO 2 to silver NPs decreased their antimicrobial activity against C. trachomatis up to 27·92-fold. In summary, nonactivated TiO 2 NPs could increase the replication of C. trachomatis and decrease the antimicrobial activity of silver NPs. The food industry or drug delivery use of TiO 2 NPs could enhance the growth of certain intracellular pathogens and potentially worsen disease symptoms, a feature that should be further investigated. © 2017 The Society for Applied Microbiology.

In Vitro Evaluation of the Impact of the Probiotic E. coli Nissle 1917 on Campylobacter jejuni's Invasion and Intracellular Survival in Human Colonic Cells.

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Helmy, Yosra A; Kassem, Issmat I; Kumar, Anand; Rajashekara, Gireesh

2017-01-01

Campylobacter jejuni is a leading cause of bacterial food poisoning in humans. Due to the rise in antibiotic-resistant Campylobacter , there exists a need to develop antibiotic-independent interventions to control infections in humans. Here, we evaluated the impact of Escherichia coli Nissle 1917 (EcN), a probiotic strain, on C. jejuni's invasion and intracellular survival in polarized human colonic cells (HT-29). To further understand how EcN mediates its impact, the expression of 84 genes associated with tight junctions and cell adhesion was profiled in HT-29 cells after treatment with EcN and challenge with C. jejuni . The pre-treatment of polarized HT-29 cells with EcN for 4 h showed a significant effect on C. jejuni 's invasion (∼2 log reduction) of the colonic cells. Furthermore, no intracellular C. jejuni were recovered from EcN pre-treated HT-29 cells at 24 h post-infection. Other probiotic strains tested had no significant impact on C. jejuni invasion and intracellular survival. C. jejuni decreased the expression of genes associated with epithelial cells permeability and barrier function in untreated HT-29 cells. However, EcN positively affected the expression of genes that are involved in enhanced intestinal barrier function, decreased cell permeability, and increased tight junction integrity. The results suggest that EcN impedes C. jejuni invasion and subsequent intracellular survival by affecting HT-29 cells barrier function and tight junction integrity. We conclude that EcN might be a viable alternative for controlling C. jejuni infections.

The added value of chlamydia screening between 2008-2010 in reaching young people in addition to chlamydia testing in regular care; an observational study

NARCIS (Netherlands)

van Liere, Geneviève; Dukers-Muijrers, Nicole; van Bergen, Jan; Götz, Hannelore M.; Stals, Frans; Hoebe, Christian

2014-01-01

Background: Internet-based Chlamydia Screening Implementation (chlamydia screening programme) was introduced in the Netherlands in 2008-2010 to detect and treat asymptomatic infections and to limit ongoing transmission through annual testing and treatment of Chlamydia trachomatis in young people

Comparison of the population excess fraction of Chlamydia trachomatis infection on pelvic inflammatory disease at 12-months in the presence and absence of chlamydia testing and treatment

DEFF Research Database (Denmark)

Davies, Bethan; Turner, Katy M. E.; Leung, Stella

2017-01-01

BACKGROUND: The impact of Chlamydia trachomatis (chlamydia) control on the incidence of pelvic inflammatory disease (PID) is theoretically limited by the proportion of PID caused by chlamydia. We estimate the population excess fraction (PEF) of treated chlamydia infection on PID at 12-months......: The systematic review identified a single study, a randomised controlled trial of chlamydia screening (POPI-RCT). In the presence of testing and treatment PID at 12-months was attributable to treated (baseline) chlamydia infections (Manitoba: 8.86%(95%CI 7.15-10.75); Denmark: 3.84%(3.26-4.45); screened...... in settings with widespread chlamydia control (testing and treatment) and compare this to the estimated PEF of untreated chlamydia. METHODS: We used two large retrospective population-based cohorts of women of reproductive age from settings with widespread chlamydia control to calculate the PEF of treated...

Prevalence of Chlamydia Trachomatis Infection among Female ...

African Journals Online (AJOL)

Alasia Datonye

prevalence of and predictive risk factors for Chlamydia trachomatis infection among female undergraduate students of ... manage and associated with severe sequelae. Key Words: – Prevalence; Chlamydia trachomatis; ... genital infection during pregnancy increases the risk of spontaneous abortion, premature delivery and ...

Getting “Inside” Type I IFNs: Type I IFNs in Intracellular Bacterial Infections

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Deann T. Snyder

2017-01-01

Full Text Available Type I interferons represent a unique and complex group of cytokines, serving many purposes during innate and adaptive immunity. Discovered in the context of viral infections, type I IFNs are now known to have myriad effects in infectious and autoimmune disease settings. Type I IFN signaling during bacterial infections is dependent on many factors including whether the infecting bacterium is intracellular or extracellular, as different signaling pathways are activated. As such, the repercussions of type I IFN induction can positively or negatively impact the disease outcome. This review focuses on type I IFN induction and downstream consequences during infection with the following intracellular bacteria: Chlamydia trachomatis, Listeria monocytogenes, Mycobacterium tuberculosis, Salmonella enterica serovar Typhimurium, Francisella tularensis, Brucella abortus, Legionella pneumophila, and Coxiella burnetii. Intracellular bacterial infections are unique because the bacteria must avoid, circumvent, and even co-opt microbial “sensing” mechanisms in order to reside and replicate within a host cell. Furthermore, life inside a host cell makes intracellular bacteria more difficult to target with antibiotics. Because type I IFNs are important immune effectors, modulating this pathway may improve disease outcomes. But first, it is critical to understand the context-dependent effects of the type I IFN pathway in intracellular bacterial infections.

Prevalence of Chlamydia trachomatis Infection among Women ...

African Journals Online (AJOL)

The prevalence of Chlamydia trachomatis infection was investigated among 100 women attending infertility clinics and compared with another subset of 100 pregnant women who served as control. Chlamydia trachomatis antigen detection cassette supplied by Biomil Diagnostics was used to detect the presence of ...

Exploring Chlamydia Positivity among Females on College Campuses, 2008-2010

Science.gov (United States)

Habel, Melissa A.; Leichliter, Jami S.; Torrone, Elizabeth

2016-01-01

Objective: Describe chlamydia positivity among young women tested at college health centers by student characteristics: age, race/ethnicity, and institution type. Participants: During 2008-2010, colleges participating in a national infertility prevention program provided chlamydia testing data from females aged 18-24. Methods: Chlamydia positivity…

Chlamydiaceae Genomics Reveals Interspecies Admixture and the Recent Evolution of Chlamydia abortus Infecting Lower Mammalian Species and Humans.

Science.gov (United States)

Joseph, Sandeep J; Marti, Hanna; Didelot, Xavier; Castillo-Ramirez, Santiago; Read, Timothy D; Dean, Deborah

2015-10-27

Chlamydiaceae are obligate intracellular bacteria that cause a diversity of severe infections among humans and livestock on a global scale. Identification of new species since 1989 and emergence of zoonotic infections, including abortion in women, underscore the need for genome sequencing of multiple strains of each species to advance our knowledge of evolutionary dynamics across Chlamydiaceae. Here, we genome sequenced isolates from avian, lower mammalian and human hosts. Based on core gene phylogeny, five isolates previously classified as Chlamydia abortus were identified as members of Chlamydia psittaci and Chlamydia pecorum. Chlamydia abortus is the most recently emerged species and is a highly monomorphic group that lacks the conserved virulence-associated plasmid. Low-level recombination and evidence for adaptation to the placenta echo evolutionary processes seen in recently emerged, highly virulent niche-restricted pathogens, such as Bacillus anthracis. In contrast, gene flow occurred within C. psittaci and other Chlamydiaceae species. The C. psittaci strain RTH, isolated from a red-tailed hawk (Buteo jamaicensis), is an outlying strain with admixture of C. abortus, C. psittaci, and its own population markers. An average nucleotide identity of less than 94% compared with other Chlamydiaceae species suggests that RTH belongs to a new species intermediary between C. psittaci and C. abortus. Hawks, as scavengers and predators, have extensive opportunities to acquire multiple species in their intestinal tract. This could facilitate transformation and homologous recombination with the potential for new species emergence. Our findings indicate that incubator hosts such as birds-of-prey likely promote Chlamydiaceae evolution resulting in novel pathogenic lineages. © The Author(s) 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

The chlamydial functional homolog of KsgA confers kasugamycin sensitivity to Chlamydia trachomatis and impacts bacterial fitness

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Maurelli Anthony T

2009-12-01

Full Text Available Abstract Background rRNA adenine dimethyltransferases, represented by the Escherichia coli KsgA protein, are highly conserved phylogenetically and are generally not essential for growth. They are responsible for the post-transcriptional transfer of two methyl groups to two universally conserved adenosines located near the 3'end of the small subunit rRNA and participate in ribosome maturation. All sequenced genomes of Chlamydia reveal a ksgA homolog in each species, including C. trachomatis. Yet absence of a S-adenosyl-methionine synthetase in Chlamydia, the conserved enzyme involved in the synthesis of the methyl donor S-adenosyl-L-methionine, raises a doubt concerning the activity of the KsgA homolog in these organisms. Results Lack of the dimethylated adenosines following ksgA inactivation confers resistance to kasugamycin (KSM in E. coli. Expression of the C. trachomatis L2 KsgA ortholog restored KSM sensitivity to the E. coli ksgA mutant, suggesting that the chlamydial KsgA homolog has specific rRNA dimethylase activity. C. trachomatis growth was sensitive to KSM and we were able to isolate a KSM resistant mutant of C. trachomatis containing a frameshift mutation in ksgA, which led to the formation of a shorter protein with no activity. Growth of the C. trachomatis ksgA mutant was negatively affected in cell culture highlighting the importance of the methylase in the development of these obligate intracellular and as yet genetically intractable pathogens. Conclusion The presence of a functional rRNA dimethylase enzyme belonging to the KsgA family in Chlamydia presents an excellent chemotherapeutic target with real potential. It also confirms the existence of S-adenosyl-methionine - dependent methylation reactions in Chlamydia raising the question of how these organisms acquire this cofactor.

Management of Chlamydia trachomatis genital tract infection: screening and treatment challenges

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Brandie D Taylor

2011-01-01

Full Text Available Brandie D Taylor, Catherine L HaggertyUniversity of Pittsburgh, Department of Epidemiology, Pittsburgh, PA, USAAbstract: Chlamydia trachomatis is a prevalent sexually transmitted infection that can lead to serious reproductive morbidity. Management and control of C. trachomatis is a challenge, largely due to its asymptomatic nature and our incomplete understanding of its natural history. Although chlamydia screening programs have been implemented worldwide, several countries have observed increasing rates of reported chlamydia cases. We reviewed the literature relating to the long-term complications of C. trachomatis, as well as screening strategies, treatment, and prevention strategies for reducing chlamydia in the population. Articles from 1950–2010 were identified through a Medline search using the keyword “Chlamydia trachomatis” combined with “screening”, “pelvic inflammatory disease”, “endometritis”, “salpingitis”, “infertility”, "ectopic pregnancy”, “urethritis”, “epididymitis”, “proctitis”, “prostatitis”, “reinfection”, “cost-effectiveness”, “treatment”, “vaccines”, or “prevention”. Progression of C. trachomatis varies, and recurrent infections are common. Currently, there is limited evidence on the effectiveness of chlamydia screening. Higher quality studies are needed to determine the efficacy of more frequent screening, on a broader range of sequelae, including infertility and ectopic pregnancy, in addition to pelvic inflammatory disease. Studies should focus on delineating the natural history of recurrent infections, paying particular attention to treatment failures. Furthermore, alternatives to screening, such as vaccines, should continue to be explored.Keywords: Chlamydia trachomatis, sexually transmitted disease, chlamydia screening, chlamydia treatment

The formation of lipid droplets favors intracellular Mycobacterium leprae survival in SW-10, non-myelinating Schwann cells.

Science.gov (United States)

Jin, Song-Hyo; An, Sung-Kwan; Lee, Seong-Beom

2017-06-01

Leprosy is a chronic infectious disease that is caused by the obligate intracellular pathogen Mycobacterium leprae (M.leprae), which is the leading cause of all non-traumatic peripheral neuropathies worldwide. Although both myelinating and non-myelinating Schwann cells are infected by M.leprae in patients with lepromatous leprosy, M.leprae preferentially invades the non-myelinating Schwann cells. However, the effect of M.leprae infection on non-myelinating Schwann cells has not been elucidated. Lipid droplets (LDs) are found in M.leprae-infected Schwann cells in the nerve biopsies of lepromatous leprosy patients. M.leprae-induced LD formation favors intracellular M.leprae survival in primary Schwann cells and in a myelinating Schwann cell line referred to as ST88-14. In the current study, we initially characterized SW-10 cells and investigated the effects of LDs on M.leprae-infected SW-10 cells, which are non-myelinating Schwann cells. SW-10 cells express S100, a marker for cells from the neural crest, and NGFR p75, a marker for immature or non-myelinating Schwann cells. SW-10 cells, however, do not express myelin basic protein (MBP), a marker for myelinating Schwann cells, and myelin protein zero (MPZ), a marker for precursor, immature, or myelinating Schwann cells, all of which suggests that SW-10 cells are non-myelinating Schwann cells. In addition, SW-10 cells have phagocytic activity and can be infected with M. leprae. Infection with M. leprae induces the formation of LDs. Furthermore, inhibiting the formation of M. leprae-induced LD enhances the maturation of phagosomes containing live M.leprae and decreases the ATP content in the M. leprae found in SW-10 cells. These facts suggest that LD formation by M. leprae favors intracellular M. leprae survival in SW-10 cells, which leads to the logical conclusion that M.leprae-infected SW-10 cells can be a new model for investigating the interaction of M.leprae with non-myelinating Schwann cells.

Dysuria in the Emergency Department: Missed Diagnosis of Chlamydia trachomatis

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Morgan D. Wilbanks

2014-03-01

Full Text Available Introduction: The clinical presentation of genital Chlamydia trachomatis infection (chlamydia in women is often indistinguishable from a urinary tract infection. While merited in the setting of dysuria, emergency department (ED clinicians do not routinely test for chlamydia in women. The primary aim of our study was to evaluate the frequency of chlamydia testing among women presenting to the ED with dysuria. Methods: We conducted a retrospective chart review of women 19-25 years of age presenting with dysuria to an urban ED and who had been coded with urinary tract infection (UTI as their primary diagnosis (ICD-9 599.0 from October 2005 to March 2011. We excluded women who were pregnant, had underlying anatomical or neurological urinary system pathology, had continuation of symptoms from UTI or a sexually transmitted infection (STI diagnosed elsewhere, or were already on antibiotics for a UTI or STI. We identified the rates of sexual history screening, pelvic examination and chlamydia assay testing and evaluated predictors using univariate and multivariate analyses. Results: Of 280 women with dysuria and a UTI diagnosis, 17% were asked about their sexual history, with 94% reporting recent sexual activity. Pelvic examination was performed in 23%. We were unable to determine the overall chlamydia prevalence as only 20% of women in the cohort were tested. Among the 20% of women tested for chlamydia infection, 21% tested positive. Only 42% of chlamydia-positive women were prescribed treatment effective for chlamydia (azithromycin or doxycycline at their visit; the remaining were prescribed UTI treatment not effective against chlamydia. Predictors of sexual history screening included vaginal bleeding (OR 5.4, 95% CI=1.5 to 19.6 and discharge (OR 2.8, 95% CI=1.1 to 6.9. Predictors of a pelvic examination being performed included having a complaint of vaginal discharge (OR 11.8, 95% CI=4.2 to 32.9, a sexual history performed (OR 2.5, 95% CI=1.1 to 5

A prospective study of the psychosocial impact of a positive Chlamydia trachomatis laboratory test.

Science.gov (United States)

Gottlieb, Sami L; Stoner, Bradley P; Zaidi, Akbar A; Buckel, Christina; Tran, Molly; Leichliter, Jami S; Berman, Stuart M; Markowitz, Lauri E

2011-11-01

Few data exist on potential harms of chlamydia screening. We assessed the psychosocial impact of receiving a positive Chlamydia trachomatis test result. We prospectively studied women ≥16 years of age undergoing chlamydia testing in 2 Midwestern family planning clinics. We surveyed women at baseline and about 1 month after receiving test results, using 9 validated psychosocial scales/subscales and chlamydia-specific questions. Changes in scale scores were calculated for each woman. Mean percent changes in scores for chlamydia-positive and -negative women were compared using a t test. We enrolled 1807 women (response rate, 84%). Of the 1688 women with test results, 149 (8.8%) tested positive. At follow-up, chlamydia-positive women (n = 71) had a 75% increase in anxiety about sexual aspects of their life on the Multidimensional Sexual Self-Concept Questionnaire (P < 0.001), significantly greater than the 26% increase among 280 randomly selected chlamydia-negative women (P = 0.02). There were no differences for the other 8 scales/subscales, including general measures of anxiety, depression, and self-esteem. Chlamydia-positive women were more likely than chlamydia-negative women to be "concerned about chlamydia" (80% vs. 40%, P < 0.001) and to report breaking up with a main partner (33% vs. 11%, P < 0.001) at follow-up. Women testing positive reported a range of chlamydia-specific concerns. Chlamydia-positive women had significant increases in anxiety about sex and concern about chlamydia, but did not have marked changes in more general measures of psychosocial well-being about 1 month after diagnosis. Chlamydia diagnoses were associated with some disruption of relationships with main partners. Chlamydia-specific concerns may guide counseling messages to minimize psychosocial impact.

[Chlamydia pneumoniae--etiology of ophthalmia neonatorum].

Science.gov (United States)

Krásný, J; Borovanská, J; Hrubá, D

2003-07-01

The authors observed mucous discharge in palpebral aperture, accompanied by a different degree of effusion of eyelids and chemosis of conjunctivae, particularly the tarsal ones, in 12 physiological newborns. Chlamydia pneumoniae proved to be the etiological agent in the newborn ophthalmia. The eye infection was not detected in the same period of time and in the same maternity hospital in the period of observation from September 1999 to March 2001. The detection of Chlamydia pneumoniae was performed in conjunctiva smears. The impression films on slides were examined by the method of indirect immunofluorescence with the use of specific monoclonal antibodies (medac, Germany). In the early stages the secretion included a sanguineous component, which was then changing into a mucoid or mucopurulent form. The character of conjunctival symptoms was changing in the course of inflammation. Effusion of the lower transitory fold (plica) was gradually accompanied by a picture of pseudofollicular changes on the tarsal conjunctiva. Clarithromycin in the form of syrup at daily doses of 15 mg/kg/day for the period of two weeks offered an efficient therapy of the affection. Control smears after 14 days were always negative and, at the same time, the pathological finding on the conjunctivae disappeared. The nasolacrimal obstruction was the only complication of this chlamydia infection, taking place in seven sucklings, i.e. in 58%. The passage through lacrimal drainage system reappeared in all the affected infants until they reached one year of age. The remaining question to be answered is the way the newborns encountered the infection. A nosocomial infection may be the case, but Chlamydia pneumoniae could also be present in the urogenital tract of mothers and transferred to the newborn via the birth canal similarly as is the case of Chlamydia trachomatis infection. The mode of infection deserves further investigation.

Prevalence of chlamydia in patients attending gynecological clinics ...

African Journals Online (AJOL)

From the cultured samples 230 were positive for Chlamydia trachomatis and 99 positive to Chlamydia pneumoniae. Statistical analysis using the student\\'s t test at 95% confidence interval shows that there was no significant difference between the number of females and males that presented themselves for screening.

Increased incidence of gonorrhoea and chlamydia in Greenland 1990-2012

DEFF Research Database (Denmark)

Johansen, Mila Broby; Koch, Anders; Wohlfahrt, Jan

2017-01-01

BACKGROUND: Since the 1970s, Greenland has presented the highest reported incidence rates of the sexually transmitted infections (STIs) gonorrhoea and chlamydia in the Arctic regions. OBJECTIVE: This study aims to describe sex- and age-specific incidence rates of gonorrhoea and chlamydia from 1990...... to 2012 in Greenland, and to evaluate if changes in case definitions, diagnostic procedures and implementation of STI interventions during the period coincide with rate changes. DESIGN: Gonorrhoea and chlamydia cases were identified from the national STI surveillance. For 1990-2008, STI cases were...... to sex, age and calendar period. RESULTS: Gonorrhoea and chlamydia incidence rates have increased since 1995 to reach 2,555 per 100,000 person-years (PY) for gonorrhoea and 6,403 per 100,000 PY for chlamydia in 2012. From 2006 to 2012, the incidence rates among young adults aged 15-19 years were 8...

Seroevidence Of Chlamydia Trachomatis Infection In Infertile Male ...

African Journals Online (AJOL)

Given the lack of information concerning the role of Chlamydia trachomatis in male infertility, it has become imperative to analyse the quality of semen of male with seroevidence of antibody to Chlamydia trachomatis infection. A total of 156 male patients attending the Human Reproduction Research Programme/Invitro ...

Chlamydia in birds - occurrence, new species and zoonotic potential – a review

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Mitura Agata

2014-12-01

Full Text Available Chlamydiales, one of the oldest bacterial orders in evolutionary terms, are widespread among animals. Blinding trachoma, a disease caused by Chlamydia trachomatis, was already known in ancient times, whereas modern reports on psittacosis date from 1879. Though these pathogens have long been known and lead to serious health problems both in human and animals, data on Chlamydiales biology has been limited. It is due to their intracellular life style and complex developmental cycle. New molecular biological methods have been recently developed expanding the possibilities of chlamydial research and diagnosis. This paper reviews data concerning avian chlamydiosis, its aetiological agent C. psittaci, newly proposed species isolated from birds, namely C. ibidis sp. nov., C. avium sp. nov., and C. gallinacea sp. nov., and their zoonotic potential.

Chlamydia trachomatis Pgp3 Antibody Population Seroprevalence before and during an Era of Widespread Opportunistic Chlamydia Screening in England (1994-2012.

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Sarah C Woodhall

Full Text Available Opportunistic chlamydia screening of <25 year-olds was nationally-implemented in England in 2008 but its impact on chlamydia transmission is poorly understood. We undertook a population-based seroprevalence study to explore the impact of screening on cumulative incidence of chlamydia, as measured by C.trachomatis-specific antibody.Anonymised sera from participants in the nationally-representative Health Surveys for England (HSE were tested for C.trachomatis antibodies using two novel Pgp3 enzyme-linked immunosorbent assays (ELISAs as a marker of past infection. Determinants of being seropositive were explored using logistic regression among 16-44 year-old women and men in 2010 and 2012 (years when sexual behaviour questions were included in the survey (n = 1,402 women; 1,119 men. Seroprevalence trends among 16-24 year-old women (n = 3,361 were investigated over ten time points from 1994-2012.In HSE2010/2012, Pgp3 seroprevalence among 16-44 year-olds was 24.4% (95%CI 22.0-27.1 in women and 13.9% (11.8-16.2 in men. Seroprevalence increased with age (up to 33.5% [27.5-40.2] in 30-34 year-old women, 18.7% [13.4-25.6] in 35-39 year-old men; years since first sex; number of lifetime sexual partners; and younger age at first sex. 76.7% of seropositive 16-24 year-olds had never been diagnosed with chlamydia. Among 16-24 year-old women, a non-significant decline in seroprevalence was observed from 2008-2012 (prevalence ratio per year: 0.94 [0.84-1.05].Our application of Pgp3 ELISAs demonstrates a high lifetime risk of chlamydia infection among women and a large proportion of undiagnosed infections. A decrease in age-specific cumulative incidence following national implementation of opportunistic chlamydia screening has not yet been demonstrated. We propose these assays be used to assess impact of chlamydia control programmes.

Asymptomatic endemic Chlamydia pecorum infections reduce growth rates in calves by up to 48 percent.

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Anil Poudel

Full Text Available Intracellular Chlamydia (C. bacteria cause in cattle some acute but rare diseases such as abortion, sporadic bovine encephalomyelitis, kerato-conjunctivitis, pneumonia, enteritis and polyarthritis. More frequent, essentially ubiquitous worldwide, are low-level, asymptomatic chlamydial infections in cattle. We investigated the impact of these naturally acquired infections in a cohort of 51 female Holstein and Jersey calves from birth to 15 weeks of age. In biweekly sampling, we measured blood/plasma markers of health and infection and analyzed their association with clinical appearance and growth in dependence of chlamydial infection intensity as determined by mucosal chlamydial burden or contemporaneous anti-chlamydial plasma IgM. Chlamydia 23S rRNA gene PCR and ompA genotyping identified only C. pecorum (strains 1710S, Maeda, and novel strain Smith3v8 in conjunctival and vaginal swabs. All calves acquired the infection but remained clinically asymptomatic. High chlamydial infection associated with reduction of body weight gains by up to 48% and increased conjunctival reddening (P<10(-4. Simultaneously decreased plasma albumin and increased globulin (P<10(-4 suggested liver injury by inflammatory mediators as mechanisms for the growth inhibition. This was confirmed by the reduction of plasma insulin like growth factor-1 at high chlamydial infection intensity (P<10(-4. High anti-C. pecorum IgM associated eight weeks later with 66% increased growth (P = 0.027, indicating a potential for immune protection from C. pecorum-mediated growth depression. The worldwide prevalence of chlamydiae in livestock and their high susceptibility to common feed-additive antibiotics suggests the possibility that suppression of chlamydial infections may be a major contributor to the growth promoting effect of feed-additive antibiotics.

Chlamydia and lymphogranuloma venereum in Canada: 2003-2012 Summary Report

Science.gov (United States)

Totten, S; MacLean, R; Payne, E; Severini, A

2015-01-01

Background Chlamydia continues to be the most commonly reported sexually transmitted infection in Canada. Lymphogranuloma venereum (LGV), caused by certain serovars of Chlamydia trachomatis, is becoming established in some populations in a number of Western countries. Objective To identify trends in reported cases of chlamydia and LGV in Canada from January 1, 2003 to December 31, 2012. Methods Notifiable disease data on chlamydia were submitted to the Public Health Agency of Canada by provincial and territorial epidemiological units and summarized at the national level by age and sex. Confirmatory testing for suspected LGV cases and serovar subtyping were performed by the National Microbiology Laboratory (NML). Where possible, provincial/territorial health authorities use a standardized national case report form to collect enhanced epidemiological data on each case and to submit the data to the Agency. Results Rates of reported cases of chlamydia increased by 57.6%, from 189.6 to 298.7 per 100,000 between 2003 and 2012. The rate of reported cases of chlamydia among females (383.5 per 100,000) was almost twice as high as that among males (212.0 per 100,000), although the highest relative rate increase occurred among males. In both males and females, the rates of chlamydia were highest in those aged 20 to 24 years. From 2004 to 2012, 170 cases of LGV were reported to the Agency by provincial health authorities (including 104 confirmed and 66 probable cases). In 2012, case reports were received on 12 confirmed and probable cases, compared to 38 laboratory-positive cases confirmed by the NML. Conclusion In Canada, as in many countries, chlamydia rates have markedly increased over the last 10 years, in part due to improved diagnosis through nucleic acid amplification (NAAT) testing. Consistent with trends in Europe and other countries, LGV is emerging in Canada among men who have sex with men (MSM). PMID:29769927

Importancia clínica de las Chlamydias

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Digna Llorente Molina

Full Text Available Introducción: las infecciones por Chlamydia han alcanzado alta incidencia en el mundo. Constituyen importantes patógenos para los animales y el hombre. En la especie humana pueden ocasionar múltiples infecciones en diferentes órganos y sistemas de órganos. Objetivo: resumir los aspectos más novedosos relacionados con las Chlamydias en cuanto a sus características y formas de evitarla. Métodos: se realizó una revisión bibliográfica sobre la importancia clínica de las Chlamydias en la especie humana y su elevada incidencia. Se consultó la base de datos Medline disponible en INFOMED, de donde se extrajeron referencias bibliográficas entre los años 1995 y 2011, acerca de algunos aspectos etiológicos, clínicos, diagnósticos y terapéuticos de acuerdo a los últimos apuntes más relevantes en la literatura médica sobre Chlamydias y su relación con el hombre. Resultados: la Chlamydia Trachomatis en particular responsable del tracoma, primera causa de ceguera prevenible, provoca un impacto deletéreo en la salud reproductiva, produciendo entidades como abortos espontáneos, rotura prematura de membranas, restricción del crecimiento intrauterino, endometritis, conjuntivitis y neumonía del recién nacido. Es responsable además de Linfogranuloma Venéreo, Uretritis no Gonocóccica, Síndrome de Reiter, Enfermedad Inflamatoria Pélvica, Síndrome de Fitz Hugh Curtis, Embarazo Ectópico Crónico, Dolor Pélvico Crónico y más recientemente Carcinoma Cervical, entre otras. Conclusiones: partiendo de la base del impacto social y económico que tiene la infección por Chlamydias en el mundo y en nuestro país, pudimos resumir los aspectos más novedosos en cuanto a los tipos, infecciones que causan y sus características, diagnóstico, terapéutica y medidas generales para evitarlas o reducir su impacto negativo en la sociedad.

Genomic Relatedness of Chlamydia Isolates Determined by Amplified Fragment Length Polymorphism Analysis

OpenAIRE

Meijer, Adam; Morré, Servaas A.; Van Den Brule, Adriaan J. C.; Savelkoul, Paul H. M.; Ossewaarde, Jacobus M.

1999-01-01

The genomic relatedness of 19 Chlamydia pneumoniae isolates (17 from respiratory origin and 2 from atherosclerotic origin), 21 Chlamydia trachomatis isolates (all serovars from the human biovar, an isolate from the mouse biovar, and a porcine isolate), 6 Chlamydia psittaci isolates (5 avian isolates and 1 feline isolate), and 1 Chlamydia pecorum isolate was studied by analyzing genomic amplified fragment length polymorphism (AFLP) fingerprints. The AFLP procedure was adapted from a previously...

Thioredoxin-1 promotes survival in cells exposed to S-nitrosoglutathione: Correlation with reduction of intracellular levels of nitrosothiols and up-regulation of the ERK1/2 MAP Kinases

International Nuclear Information System (INIS)

Arai, Roberto J.; Ogata, Fernando T.; Batista, Wagner L.; Masutani, Hiroshi; Yodoi, Junji; Debbas, Victor; Augusto, Ohara; Stern, Arnold; Monteiro, Hugo P.

2008-01-01

Accumulating evidence indicates that post-translational protein modifications by nitric oxide and its derived species are critical effectors of redox signaling in cells. These protein modifications are most likely controlled by intracellular reductants. Among them, the importance of the 12 kDa dithiol protein thioredoxin-1 (TRX-1) has been increasingly recognized. However, the effects of TRX-1 in cells exposed to exogenous nitrosothiols remain little understood. We investigated the levels of intracellular nitrosothiols and survival signaling in HeLa cells over-expressing TRX-1 and exposed to S-nitrosoglutahione (GSNO). A role for TRX-1 expression on GSNO catabolism and cell viability was demonstrated by the concentration-dependent effects of GSNO on decreasing TRX-1 expression, activation of caspase-3, and increasing cell death. The over-expression of TRX-1 in HeLa cells partially attenuated caspase-3 activation and enhanced cell viability upon GSNO treatment. This was correlated with reduction of intracellular levels of nitrosothiols and increasing levels of nitrite and nitrotyrosine. The involvement of ERK, p38 and JNK pathways were investigated in parental cells treated with GSNO. Activation of ERK1/2 MAP kinases was shown to be critical for survival signaling. In cells over-expressing TRX-1, basal phosphorylation levels of ERK1/2 MAP kinases were higher and further increased after GSNO treatment. These results indicate that the enhanced cell viability promoted by TRX-1 correlates with its capacity to regulate the levels of intracellular nitrosothiols and to up-regulate the survival signaling pathway mediated by the ERK1/2 MAP kinases

Chlamydia infections in women

Science.gov (United States)

... other types of STIs. Most common STIs are: Gonorrhea HIV/AIDS Syphilis Hepatitis Herpes Even if you ... you from passing the STIs back and forth. Gonorrhea often occurs with chlamydia. Therefore, treatment for gonorrhea ...

Deteccion de Chlamydia trachomatis en muestras uretrales mediante inmunofluorescencia directa Detecção de Chlamydia trachomatis em amostras uretrais mediante imunofluorescência direta Detection of Chlamydia trachomatis in urethral samples by means of direct immunofluorescence

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Myra Wilson Schuster

1989-12-01

Full Text Available Se estudiaron 82 pacientes con uretritis para la búsqueda de Chlamydia trachomatis mediante inmunofluorescencia directa, Neisscria gonorrhoeae, Mycoplastna y Ureaplasma mediante métodos estándar. Se encontró un 19,5% de Chlamydia trachomatis y en 11 de ellos (68,8% se encontró asociada a otras bacterias y estos pacientes presentó una secreción escasa-gelatinosa.Em 82 doentes com uretrite foi pesquisada a presença de Chlamydia trachomatis, utilizando a prova da imunofluorescência direta, e de Neisseria gonorrhoeae, Mycoplasma e Ureaplasma, utilizando os métodos padrões. Ch. trachomatis foi encontrada em 19,5% dos casos, sendo que em 11 deles (68,8% observou-se associação entre Chlamydia e as outras bactérias pesquisadas. Nesses pacientes observou-se presença de secreção uretral escassa e de aspecto gelatinoso.The presence of Chlamydia trachomatis was studied by the direct immunofluorescence test, as also was that of Neisseria gonorrhoeae, Mycoplasma and Ureaplasma by the standard methods, in 82 patients with urethral discharge. Ch. trachomatis was found in 19.5% (16 of the cases and in 11 of them (68.8% there was association with the other bacteria investigated. This eleven patients presented a scanty gelatinous discharge.

Adrenaline in pro-oxidant conditions elicits intracellular survival pathways in isolated rat cardiomyocytes

International Nuclear Information System (INIS)

Costa, Vera Marisa; Silva, Renata; Ferreira, Rita; Amado, Francisco; Carvalho, Felix; Bastos, Maria Lourdes de; Albuquerque Carvalho, Rui; Carvalho, Marcia; Remiao, Fernando

2009-01-01

In several pathologic conditions, like cardiac ischemia/reperfusion, the sustained elevation of plasma and interstitial catecholamine levels, namely adrenaline (ADR), and the generation of reactive oxygen species (ROS) are hallmarks. The present work aimed to investigate in cardiomyocytes which intracellular signalling pathways are altered by ADR redox ability. To mimic pathologic conditions, freshly isolated calcium tolerant cardiomyocytes from adult rat were incubated with ADR alone or in the presence of a system capable of generating ROS [(xanthine with xanthine oxidase) (X/XO)]. ADR elicited a pro-oxidant signal with generation of reactive species, which was largely magnified by the ROS generating system. However, no change in cardiomyocytes viability was observed. The pro-oxidant signal promoted the translocation to the nucleus of the transcription factors, Heat shock factor-1 (HSF-1) and Nuclear factor-κB (NF-κB). In addition, proteasome activity was compromised in the experimental groups where the generation of reactive species occurred. The decrease in the proteasome activity of the ADR group resulted from its redox sensitivity, since the activity was recovered by adding the ROS scavenger, tiron. Proteasome inhibition seemed to elicit an increase in HSP70 levels. Furthermore, retention of mitochondrial cytochrome c and inhibition of caspase 3 activity were observed by X/XO incubation in presence or absence of ADR. In conclusion, in spite of all the insults inflicted to the cardiomyocytes, they were capable to activate intracellular responses that enabled their survival. These mechanisms, namely the pathways altered by catecholamine proteasome inhibition, should be further characterized, as they could be of relevance in the ischemia preconditioning and the reperfusion injury

Chlamydia - CDC Fact Sheet

Science.gov (United States)

... Archive STDs Home Page Bacterial Vaginosis (BV) Chlamydia Gonorrhea Genital Herpes Hepatitis HIV/AIDS & STDs Human Papillomavirus ( ... sheet Pelvic Inflammatory Disease (PID) – CDC fact sheet Gonorrhea – CDC fact sheet STDs Home Page Bacterial Vaginosis ( ...

Serological diagnosis of Chlamydia infections: proposal of a cost-effective approach

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Gino Ciarrocchi

2008-06-01

Full Text Available Infections caused by genus Chlamydia are challenging for phisicians, as a results of a complicated pathogenesis and a variable clinical picture. Furthermore, potential sequelae following Chlamydia trachomatis, Chlamydia pneumoniae, Chlamydia psittaci infections are of clinical relevant interest. Serodiagnosis is a clue tool when the direct antigen research or the bacteria fragments detection is impaired. Some serological tests such as the ELISA or the indirect micro-immunofluorescence methods are routinely performed. To improve the diagnostic efficiency of these tests, a selective coating of specie-specific reactive antigens on microwells or on microscopic slides is proposed.A highly selective coating is essential to generate a specific immune response for each Chlamydia species and high levels of distinct IgA, IgG, IgM antibody classes.The goal of serology is the diagnostic value of results, therefore the correct choice of the best screening and confirmation test is of extreme relevance due to the clinical impact of results for the therapeutical approach and management of acute and chronic infections. In conclusion, a quantitative specific anti-Chlamydia IgG and IgA antibody detection is a useful method to improve the follow up of complicated chronic clinical sequelae.

Prevalence of Chlamydia trachomatis infection in women, heterosexual men and MSM visiting HIV counselling institutions in North Rhine-Westphalia, Germany - should Chlamydia testing be scaled up?

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Anne Lallemand

2016-10-01

Full Text Available Abstract Background Patients asking for a free anonymous HIV test may have contracted other sexually transmitted infections (STIs such as Chlamydia trachomatis, yet Chlamydia prevalence in that population is unknown. This study aimed to assess the prevalence and factors associated with Chlamydia infection in patients seeking HIV testing at local public health authorities (LPHA in order to evaluate whether Chlamydia testing should be routinely offered to them. Methods We conducted a cross-sectional study among patients (≥18 years attending 18 LPHA in North Rhine-Westphalia from November 2012 to September 2013. LPHA collected information on participants’ socio-demographic characteristics, sexual and HIV testing behaviours, previous STI history and clinical symptoms. Self-collected vaginal swabs and urine (men were analysed by Transcription-Mediated Amplification. We assessed overall and age-stratified Chlamydia prevalence and 95 % confidence intervals (95 % CI. Using univariate and multivariable binomial regression, we estimated adjusted prevalence ratios (aPR to identify factors associated with Chlamydia infection. Results The study population comprised 1144 (40.5 % women, 1134 (40.1 % heterosexual men and 549 (19.4 % men who have sex with men (MSM; median age was 30 years. Chlamydia prevalence was 5.3 % (95 % CI: 4.1–6.8 % among women, 3.2 % (95 % CI: 2.2–4.4 in heterosexual men and 3.5 % (95 % CI: 2.1–5.4 in MSM. Prevalence was highest among 18–24 year-old women (9 %; 95 % CI: 5.8–13 and heterosexual men (5.7 %; 95 % CI: 3.0–9.8 %, respectively. Among MSM, the prevalence was highest among 30–39 year-olds (4.4 %; 95 % CI: 1.9–8.5 %. Among those who tested positive, 76.7 % of women, 75.0 % of heterosexual men and 84.2 % of MSM were asymptomatic. Among women, factors associated with Chlamydia infection were young age (18–24 years versus ≥ 40 years, aPR: 3.0, 95 % CI: 1.2–7.8, having had more than 2

Analysis of the humoral immune response to Chlamydia outer membrane protein 2

DEFF Research Database (Denmark)

Mygind, P; Christiansen, Gunna; Persson, K

1998-01-01

The humoral immune response to Chlamydia outer membrane protein 2 (Omp2) was studied. Omp2 is a highly genus-conserved structural protein of all Chlamydia species, containing a variable N-terminal fragment. To analyze where the immunogenic parts were localized, seven highly purified truncated...... fusion proteins constituting different regions of the protein were produced (Chlamydia pneumoniae-Omp2aa23-aa93, Chlamydia psittaci-Omp2aa23-aa94, and Chlamydia trachomatis-Omp2aa23-aa84, aa87-aa547, aa23-aa182, aa167-aa434, aa420-aa547). By an enzyme-linked immunosorbent assay with serologically defined...... patient sera, Omp2 was found to be a major immunogen of both C. pneumoniae and C. trachomatis infections (P species-specific anti-Omp2 immunoglobulins were detected....

Damage/Danger Associated Molecular Patterns (DAMPs Modulate Chlamydia pecorum and C. trachomatis Serovar E Inclusion Development In Vitro.

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Cory Ann Leonard

Full Text Available Persistence, more recently termed the chlamydial stress response, is a viable but non-infectious state constituting a divergence from the characteristic chlamydial biphasic developmental cycle. Damage/danger associated molecular patterns (DAMPs are normal intracellular components or metabolites that, when released from cells, signal cellular damage/lysis. Purine metabolite DAMPs, including extracellular ATP and adenosine, inhibit chlamydial development in a species-specific manner. Viral co-infection has been shown to reversibly abrogate Chlamydia inclusion development, suggesting persistence/chlamydial stress. Because viral infection can cause host cell DAMP release, we hypothesized DAMPs may influence chlamydial development. Therefore, we examined the effect of extracellular ATP, adenosine, and cyclic AMP exposure, at 0 and 14 hours post infection, on C. pecorum and C. trachomatis serovar E development. In the absence of de novo host protein synthesis, exposure to DAMPs immediately post or at 14 hours post infection reduced inclusion size; however, the effect was less robust upon 14 hours post infection exposure. Additionally, upon exposure to DAMPs immediately post infection, bacteria per inclusion and subsequent infectivity were reduced in both Chlamydia species. These effects were reversible, and C. pecorum exhibited more pronounced recovery from DAMP exposure. Aberrant bodies, typical in virus-induced chlamydial persistence, were absent upon DAMP exposure. In the presence of de novo host protein synthesis, exposure to DAMPs immediately post infection reduced inclusion size, but only variably modulated chlamydial infectivity. Because chlamydial infection and other infections may increase local DAMP concentrations, DAMPs may influence Chlamydia infection in vivo, particularly in the context of poly-microbial infections.

Structural and Biochemical Characterization of Chlamydia trachomatis Hypothetical Protein CT263 Supports That Menaquinone Synthesis Occurs through the Futalosine Pathway*

Science.gov (United States)

Barta, Michael L.; Thomas, Keisha; Yuan, Hongling; Lovell, Scott; Battaile, Kevin P.; Schramm, Vern L.; Hefty, P. Scott

2014-01-01

The obligate intracellular human pathogen Chlamydia trachomatis is the etiological agent of blinding trachoma and sexually transmitted disease. Genomic sequencing of Chlamydia indicated this medically important bacterium was not exclusively dependent on the host cell for energy. In order for the electron transport chain to function, electron shuttling between membrane-embedded complexes requires lipid-soluble quinones (e.g. menaquionone or ubiquinone). The sources or biosynthetic pathways required to obtain these electron carriers within C. trachomatis are poorly understood. The 1.58Å crystal structure of C. trachomatis hypothetical protein CT263 presented here supports a role in quinone biosynthesis. Although CT263 lacks sequence-based functional annotation, the crystal structure of CT263 displays striking structural similarity to 5′-methylthioadenosine nucleosidase (MTAN) enzymes. Although CT263 lacks the active site-associated dimer interface found in prototypical MTANs, co-crystal structures with product (adenine) or substrate (5′-methylthioadenosine) indicate that the canonical active site residues are conserved. Enzymatic characterization of CT263 indicates that the futalosine pathway intermediate 6-amino-6-deoxyfutalosine (kcat/Km = 1.8 × 103 m−1 s−1), but not the prototypical MTAN substrates (e.g. S-adenosylhomocysteine and 5′-methylthioadenosine), is hydrolyzed. Bioinformatic analyses of the chlamydial proteome also support the futalosine pathway toward the synthesis of menaquinone in Chlamydiaceae. This report provides the first experimental support for quinone synthesis in Chlamydia. Menaquinone synthesis provides another target for agents to combat C. trachomatis infection. PMID:25253688

Immunoelectron microscopy of lipopolysaccharide in Chlamydia trachomatis

DEFF Research Database (Denmark)

Birkelund, Svend; Lundemose, AG; Christiansen, Gunna

1989-01-01

Monoclonal antibodies (MAb) specific for Chlamydia trachomatis lipopolysaccharide (LPS) and major outer membrane protein (MOMP) were used for immunoelectron microscopy analysis. MAb specific for MOMP showed strong reaction with the chlamydial surface, whereas MAb specific for LPS showed strong...... association of gold particles with the periphery of the chlamydial body. After fixation of the chlamydia cells, the reactivity was, however, similar to the anti-MOMP reactivity. Enzyme-linked immunosorbent assay showed that MAb specific for LPS could remove LPS from the chlamydial membrane....

Seroepidemiologic survey for Chlamydia suis in wild boar (Sus scrofa) populations in Italy.

Science.gov (United States)

Di Francesco, Antonietta; Donati, Manuela; Morandi, Federico; Renzi, Maria; Masia, Marco Antonio; Ostanello, Fabio; Salvatore, Daniela; Cevenini, Roberto; Baldelli, Raffaella

2011-07-01

We used serology to estimate the prevalence of exposure to chlamydiae in Italian populations of wild boars (Sus scrofa). Sera from 173 hunter-killed wild boars harvested during the 2006-2009 hunting seasons in three Italian regions were tested for antibodies to Chlamydia suis, Chlamydophila pecorum, Chlamydophila abortus, and Chlamydophila psittaci by the microimmunofluorescence test. Antibody titers to chlamydiae ≥ 1:32 were detected in 110 of the 173 samples tested (63.6%). Specific reactivity could be assessed only in 44 sera with antibody titers to C. suis that were two- to threefold higher than antibody titers against the other chlamydial species; the other 66 sera had similar reactivity against all the chlamydia species tested. Antibody to C. suis was detected in sera from wild boar populations with rare or no known contact with domestic pigs. These results suggest that the wild boar could be a chlamydia reservoir and may acquire chlamydiae independent of contacts with the domestic pig.

Chlamydia pneumoniae Infection in Atherosclerotic Lesion Development through Oxidative Stress: A Brief Overview

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Rosa Sessa

2013-07-01

Full Text Available Chlamydia pneumoniae, an obligate intracellular pathogen, is known as a leading cause of respiratory tract infections and, in the last two decades, has been widely associated with atherosclerosis by seroepidemiological studies, and direct detection of the microorganism within atheroma. C. pneumoniae is presumed to play a role in atherosclerosis for its ability to disseminate via peripheral blood mononuclear cells, to replicate and persist within vascular cells, and for its pro-inflammatory and angiogenic effects. Once inside the vascular tissue, C. pneumoniae infection has been shown to induce the production of reactive oxygen species in all the cells involved in atherosclerotic process such as macrophages, platelets, endothelial cells, and vascular smooth muscle cells, leading to oxidative stress. The aim of this review is to summarize the data linking C. pneumoniae-induced oxidative stress to atherosclerotic lesion development.

Seroprevalence of Chlamydia trachomatis in Enugu, Nigeria.

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Ikeme, A C; Ezegwui, H U; Ikeako, L C; Agbata, I; Agbata, E

2011-01-01

Chlamydia infections in women cause pelvic inflammatory disease, which often results in devastating consequences of infertility, ectopic pregnancy, or chronic pelvic pain. The infection is largely asymptomatic. To determine the seroprevalence of Chlamydia trachomatis in Enugu, South Eastern Nigeria. A population-based prospective study comprising female residents of Enugu, South Eastern Nigeria. Indirect solid phase enzyme immunoassay of Chlamydia antibodies was done using ImmunoComb C0. Trachomatis IgG Kit (Orgenics). The population comprised 136 female undergraduate students and 150 non-student women. The overall prevalence of C. trachomatis in the population studied was 29.4%. The percentage of subjects who admitted to be having multiple sexual partners was higher among the student population (71.2%) compared to those from the non-student population (28.8%). The highest percentage of seroprevalence was 28 (33.3%) in the age group of 20-24 years for the student population and 18 (21.4%) in the age group of 25-29 years for the non-student population. The highest seroprevalence of C. trachomatis antibodies (69.0%) in both populations was observed in females without any history of infection. Females that had pelvic inflammatory disease, sexually transmitted infection, and secondary infertility assayed for C. trachomatis had seroprevalence levels of 19%, 9.5%, and 2.4%, respectively. There was a positive correlation between positive Chlamydia assay and the type of subject population (student or non-student) with r2 value of 1.55 at P Nigeria.

[Chlamydia trachomatis and urogenital mycoplasms in nonconococcal urethritis in men].

Science.gov (United States)

Vesić, Sonja; Vukićević, Jelica; Gvozdenović, Eleonora; Skiljević, Dusan; Janosević, Slobodanka; Medenica, Ljiljana

2010-01-01

Nongonococcal urethritis is the most common sexually transmitted infection in men, with vast majority of the etiological agents such as Chlamydia trachomatis, followed by urogenital mycoplasmas. The aim of this study was to determine the prevalence of Chlamydia trachomatis, Ureaplasma urealyticum and Mycoplasma hominis in nongonococcal urethritis in men, and to examine infections associated with these agents. Material and methods 299 sexually active, heterosexual men with nongonococcal urethritis were included into the study. Urethral samples were taken with a dacron swab placed into the urethra up to 2-3 cm. The Direct immunofluorescence technique was performed for identification of Chlamydia trachomatis. Ureaplasma urealyticum and Mycoplasma hominis were detected with Mycoplasma IST assay. Chlamydia trachomatis was detected in 22.75%, Uraeplasma urealyticum in 21.08% and Mycoplasma hominis in 8.02% cases. We found no significant differences in prevalence between Chlamydia trachomatis and Ureaplasma urealyticym (p > 0.05). Monoinfections were found in 51.85% with significantly higher rate (p urethritis with prevalence of 51.85% in monoinfections and 11.70% in associated infections. In 36.45% of cases the etiology of urethritis was not elucidated. These results suggest that more sensitive diagnostic tool should be applied when searching for the derailed etiology of nongonococcal urethritis.

Extended semen for artificial insemination in swine as a potential transmission mechanism for infectious Chlamydia suis.

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Hamonic, G; Pasternak, J A; Käser, T; Meurens, F; Wilson, H L

2016-09-01

Although typically unnoticed, Chlamydia infections in swine have been shown to be both widespread and may impact production characteristics and reproductive performance in swine. Serum titers suggest Chlamydia infection within boar studs is common, and infected boars are known to shed chlamydia in their ejaculates. Although the transmission of viruses in chilled extended semen (ES) is well established, the inclusion of antibiotics in commercially available extender is generally believed to limit or preclude the transmission of infectious bacteria. The objective of this study was to evaluate the potential of ES used in artificial insemination to support transmission of the obligate intracellular bacteria Chlamydia suis (C suis) under standard industry conditions. First, the effect of C suis on sperm quality during storage was assessed by flow cytometry. Only concentrations above 5 × 10(5) viable C suis/mL caused significant spermicidal effects which only became evident after 7 days of storage at 17 °C. No significant effect on acrosome reaction was observed using any chlamydial concentration. Next, an in vitro infection model of swine testicular fibroblast cells was established and used to evaluate the effect of chilled storage on C suis viability under variable conditions. Storage in Androhep ES reduced viability by 34.4% at a multiplicity of infection of 1.25, an effect which increased to 53.3% when the multiplicity of infection decreased to 0.1. Interestingly, storage in semen extender alone (SE) or ES with additional antibiotics had no effect on bacterial viability. To rule out a secondary effect on extender resulting from metabolically active sperm, C suis was stored in fresh and expended SE and again no significant effect on bacterial viability was observed. Fluorescent microscopy of C suis in ES shows an association between bacteria and the remaining gel fraction after storage suggesting that the apparent reduction of bacterial viability in the presence

Distinct intensity of host-pathogen interactions in Chlamydia psittaci- and Chlamydia abortus-infected chicken embryos.

Science.gov (United States)

Braukmann, Maria; Sachse, Konrad; Jacobsen, Ilse D; Westermann, Martin; Menge, Christian; Saluz, Hans-Peter; Berndt, Angela

2012-09-01

Factors and mechanisms determining the differences in virulence and host specificity between the zoonotic agents Chlamydia psittaci and Chlamydia abortus are still largely unknown. In the present study, two strains were compared for their invasiveness, virulence, and capability of eliciting an immune response in chicken embryos. On breeding day 10, embryonated chicken eggs were inoculated with 5 × 10(4) inclusion-forming units. As shown by immunohistochemistry and quantitative real-time PCR, C. psittaci displayed a significantly better capability of disseminating in the chorioallantoic membrane (CAM) and internal organs than C. abortus. The higher infectious potential of C. psittaci in birds was underlined by significantly higher mRNA expression rates of essential chlamydial genes, such as incA, groEL (in CAM, liver, and spleen), cpaf, and ftsW (in CAM). Although the immune responses to both pathogens were similar, C. psittaci elicited higher macrophage numbers and a stronger expression of a subset of immune-related proteins. The data imply that invasiveness of Chlamydia spp. and propagation in the host are not solely dependent on the level of host immune response but, even to a greater extent, on the expression of bacterial factors related to virulence. The fact that C. psittaci has coped far better than C. abortus with the avian embryo's response by upregulating essential genes may be a key to understanding the mechanisms underlying host adaptation and etiopathology.

Does population screening for Chlamydia trachomatis raise anxiety among those tested? Findings from a population based chlamydia screening study.

Science.gov (United States)

Campbell, Rona; Mills, Nicola; Sanford, Emma; Graham, Anna; Low, Nicola; Peters, Tim J

2006-04-25

The advent of urine testing for Chlamydia trachomatis has raised the possibility of large-scale screening for this sexually transmitted infection, which is now the most common in the United Kingdom. The purpose of this study was to investigate the effect of an invitation to be screened for chlamydia and of receiving a negative result on levels of anxiety, depression and self-esteem. 19,773 men and women aged 16 to 39 years, selected at random from 27 general practices in two large city areas (Bristol and Birmingham) were invited by post to send home-collected urine samples or vulvo-vaginal swabs for chlamydia testing. Questionnaires enquiring about anxiety, depression and self-esteem were sent to random samples of those offered screening: one month before the dispatch of invitations; when participants returned samples; and after receiving a negative result. Home screening was associated with an overall reduction in anxiety scores. An invitation to participate did not increase anxiety levels. Anxiety scores in men were lower after receiving the invitation than at baseline. Amongst women anxiety was reduced after receipt of negative test results. Neither depression nor self-esteem scores were affected by screening. Postal screening for chlamydia does not appear to have a negative impact on overall psychological well-being and can lead to a decrease in anxiety levels among respondents. There is, however, a clear difference between men and women in when this reduction occurs.

Does population screening for Chlamydia trachomatis raise anxiety among those tested? Findings from a population based chlamydia screening study

Directory of Open Access Journals (Sweden)

Low Nicola

2006-04-01

Full Text Available Abstract Background The advent of urine testing for Chlamydia trachomatis has raised the possibility of large-scale screening for this sexually transmitted infection, which is now the most common in the United Kingdom. The purpose of this study was to investigate the effect of an invitation to be screened for chlamydia and of receiving a negative result on levels of anxiety, depression and self-esteem. Methods 19,773 men and women aged 16 to 39 years, selected at random from 27 general practices in two large city areas (Bristol and Birmingham were invited by post to send home-collected urine samples or vulvo-vaginal swabs for chlamydia testing. Questionnaires enquiring about anxiety, depression and self-esteem were sent to random samples of those offered screening: one month before the dispatch of invitations; when participants returned samples; and after receiving a negative result. Results Home screening was associated with an overall reduction in anxiety scores. An invitation to participate did not increase anxiety levels. Anxiety scores in men were lower after receiving the invitation than at baseline. Amongst women anxiety was reduced after receipt of negative test results. Neither depression nor self-esteem scores were affected by screening. Conclusion Postal screening for chlamydia does not appear to have a negative impact on overall psychological well-being and can lead to a decrease in anxiety levels among respondents. There is, however, a clear difference between men and women in when this reduction occurs.

The prevalence and clinical significance of Chlamydia infection in island and mainland populations of Victorian koalas (Phascolarctos cinereus).

Science.gov (United States)

Patterson, Jade L S; Lynch, Michael; Anderson, Garry A; Noormohammadi, Amir H; Legione, Alistair; Gilkerson, James R; Devlin, Joanne M

2015-04-01

Chlamydia infection is known to impact the health of koalas (Phascolarctos cinereus) in New South Wales (NSW) and Queensland, but the clinical significance of Chlamydia infections in Victorian koalas is not well described. We examined the prevalence of Chlamydia infection and assessed associated health parameters in two Victorian koala populations known to be Chlamydia positive. The same testing regimen was applied to a third Victorian population in which Chlamydia had not been detected. We examined 288 koalas and collected samples from the urogenital sinus and conjunctival sacs. Detection and differentiation of Chlamydia species utilized real-time PCR and high-resolution melting curve analysis. Chlamydia pecorum was detected in two populations (prevalences: 25% and 41%, respectively) but only from urogenital sinus swabs. Chlamydia was not detected in the third population. Chlamydia pneumoniae was not detected. Chlamydia pecorum infection was positively associated with wet bottom (indicating chronic urinary tract disease) in one Chlamydia-positive population and with abnormal urogenital ultrasound findings in the other Chlamydia-positive population. The prevalence of wet bottom was similar in all populations (including the Chlamydia-free population), suggesting there is another significant cause (or causes) of wet bottom in Victorian koalas. Ocular disease was not observed. This is the largest study of Chlamydia infection in Victorian koalas, and the results suggest the potential for epidemiologic differences related to Chlamydia infections between Victorian koalas and koalas in Queensland and NSW and also between geographically distinct Victorian populations. Further studies to investigate the genotypes of C. pecorum present in Victorian koalas and to identify additional causes of wet bottom in koalas are indicated.

Changes in chlamydia control activities in Europe between 2007 and 2012: A cross-national survey

DEFF Research Database (Denmark)

van den Broek, I; Andersen, Berit; Herrmann, B

2015-01-01

Background: In 2012, the levels of chlamydia control activities including primary prevention, effective case management with partner management and surveillance were assessed in 2012 across countries in the European Union and European Economic Area (EU/EEA), on initiative of the European Centre...... indicators of chlamydia prevention and control activities; countries were assigned to one of five categories of chlamydia control. Results: In 2012, more countries than in 2007 reported availability of national chlamydia case management guidelines (80% vs. 68%), opportunistic chlamydia testing (68% vs. 44......%) and consistent use of nucleic acid amplification tests (64% vs. 36%). The number of countries reporting having a national sexually transmitted infection control strategy or a surveillance system for chlamydia did not change notably. In 2012, most countries (18/25, 72%) had implemented primary prevention...

Evaluation of the Kodak Surecell Chlamydia test for the laboratory diagnosis of adult inclusion conjunctivitis.

Science.gov (United States)

Tantisira, J G; Kowalski, R P; Gordon, Y J

1995-07-01

The Kodak Surecell Chlamydia test, a rapid enzyme immunoassay, has been reported to be highly sensitive (93%) and specific (96%) for detecting chlamydial lipopolysaccharide antigen in conjunctival specimens from infants, but has not been evaluated previously in adult conjunctival specimens. This study was designed to determine the efficacy of the Kodak Surecell Chlamydia test for the laboratory diagnosis of adult inclusion conjunctivitis. Twenty Chlamydia culture-positive conjunctival specimens from adults (true-positives) and 20 true-negative specimens were tested with the Kodak Surecell Chlamydia test. The Kodak Surecell Chlamydia test was 40% (8/20) sensitive, 100% (20/20) specific, and 70% (28/40) efficient. This study indicates that the Kodak Surecell Chlamydia test, though highly specific, is less sensitive in its ability to diagnose chlamydial conjunctivitis in adults than has been reported previously in infants.

Chlamydia and sudden infant death syndrome. A study of 166 SIDS and 30 control cases

DEFF Research Database (Denmark)

Banner, Jytte; Lundemose, A G; Gregersen, M

1990-01-01

.04). Chlamydia trachomatis is an agent of pneumonia in 1-4 month-old infants who have acquired the disease from an infected cervix during birth, but other chlamydia species are also capable of causing pneumonia. The lung sections of the 32 chlamydia positive SIDS cases did not show typical histological signs......Chlamydia inclusions could be demonstrated by an immunofluorescence assay in formalin-fixed lung sections in 32 of 166 cases (19.4%) of Sudden Infant Death Syndrome (SIDS) and in the lungs of only 1 of 30 infants with a known cause of death (3.3%). The difference is statistically significant (P = 0...... of pneumonia. Even though chlamydia inclusions were detected in the lungs of 32 SIDS cases a causal relation between chlamydia infection and SIDS could not be demonstrated....

Valosin-containing protein VCP/p97 is essential for the intracellular development of Leishmania and its survival under heat stress.

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Aguiar, Bruno G; Padmanabhan, Prasad K; Dumas, Carole; Papadopoulou, Barbara

2018-06-12

VCP/p97/Cdc48 is one of the best-characterized type II cytosolic AAA+ ATPases most known for their role in ubiquitin-dependent protein quality control. Here, we provide functional insights into the role of the Leishmania VCP/p97 homolog (LiVCP) in the parasite intracellular development. We demonstrate that although LiVCP is an essential gene, L. infantum promastigotes can grow with less VCP. In contrast, growth of axenic and intracellular amastigotes is dramatically affected upon decreased LiVCP levels in heterozygous and temperature sensitive LiVCP mutants or the expression of dominant negative mutants known to specifically target the second conserved VCP ATPase domain, a major contributor of the VCP overall ATPase activity. Interestingly, these VCP mutants are also unable to survive heat stress and a temperature sensitive VCP mutant is defective in amastigote growth. Consistent with LiVCP's essential function in amastigotes, LiVCP mRNA undergoes 3'UTR-mediated developmental regulation, resulting in higher VCP expression in amastigotes. Furthermore, we show that parasite mutant lines expressing lower VCP levels or dominant negative VCP forms exhibit high accumulation of polyubiquitinated proteins and increased sensitivity to proteotoxic stress, supporting the ubiquitin-selective chaperone function of LiVCP. Together, these results emphasize the crucial role LiVCP plays under heat stress and during the parasite intracellular development. This article is protected by copyright. All rights reserved.

Activity of synthetic peptides against Chlamydia.

Science.gov (United States)

Donati, Manuela; Cenacchi, Giovanna; Biondi, Roberta; Papa, Valentina; Borel, Nicole; Vecchio Nepita, Edoardo; Magnino, Simone; Pasquinelli, Gianandrea; Levi, Aurora; Franco, Octavio L

2017-11-01

The in vitro activity of six synthetic peptides against 36 strains of Chlamydia from different origins was investigated. Clavanin MO (CMO) proved to be the most active peptide, reducing the inclusion number of all Chlamydia strains from eight different species tested by ≥50% at 10 µg mL -1 . Mastoparan L showed an equal activity against C. trachomatis, C. pneumoniae, C. suis, and C. muridarum, but did not exert any inhibitory effect against C. psittaci, C. pecorum, C. abortus, and C. avium even at 80 µg mL -1 . These data suggest that CMO could be a promising compound in the prevention and treatment of chlamydial infections. © 2017 Wiley Periodicals, Inc.

Home-based chlamydia testing of young people attending a music festival--who will pee and post?

Science.gov (United States)

Sacks-Davis, Rachel; Gold, Judy; Aitken, Campbell K; Hellard, Margaret E

2010-06-28

Chlamydia is most common among young people, but only a small proportion of Australian young people are tested annually. Home-based chlamydia testing has been piloted in several countries to increase testing rates, but uptake has been low. We aimed to identify predictors of uptake of home-based chlamydia testing to inform future testing programs. We offered home-based chlamydia testing kits to participants in a sexual behaviour cross-sectional survey conducted at a music festival in Melbourne, Australia. Those who consented received a testing kit and were asked to return their urine or vaginal swab sample via post. Nine hundred and two sexually active music festival attendees aged 16-29 completed the survey; 313 (35%) opted to receive chlamydia testing kits, and 67 of 313 (21%) returned a specimen for testing. One participant was infected with chlamydia (1% prevalence). Independent predictors of consenting to receive a testing kit included older age, knowing that chlamydia can make women infertile, reporting more than three lifetime sexual partners and inconsistent condom use. Independent predictors of returning a sample to the laboratory included knowing that chlamydia can be asymptomatic, not having had an STI test in the past six months and not living with parents. A low proportion of participants returned their chlamydia test, suggesting that this model is not ideal for reaching young people. Home-based chlamydia testing is most attractive to those who report engaging in sexual risk behaviours and are aware of the often asymptomatic nature and potential sequelae of chlamydia infection.

Home-based chlamydia testing of young people attending a music festival - who will pee and post?

Science.gov (United States)

2010-01-01

Background Chlamydia is most common among young people, but only a small proportion of Australian young people are tested annually. Home-based chlamydia testing has been piloted in several countries to increase testing rates, but uptake has been low. We aimed to identify predictors of uptake of home-based chlamydia testing to inform future testing programs. Methods We offered home-based chlamydia testing kits to participants in a sexual behaviour cross-sectional survey conducted at a music festival in Melbourne, Australia. Those who consented received a testing kit and were asked to return their urine or vaginal swab sample via post. Results Nine hundred and two sexually active music festival attendees aged 16-29 completed the survey; 313 (35%) opted to receive chlamydia testing kits, and 67 of 313 (21%) returned a specimen for testing. One participant was infected with chlamydia (1% prevalence). Independent predictors of consenting to receive a testing kit included older age, knowing that chlamydia can make women infertile, reporting more than three lifetime sexual partners and inconsistent condom use. Independent predictors of returning a sample to the laboratory included knowing that chlamydia can be asymptomatic, not having had an STI test in the past six months and not living with parents. Conclusions A low proportion of participants returned their chlamydia test, suggesting that this model is not ideal for reaching young people. Home-based chlamydia testing is most attractive to those who report engaging in sexual risk behaviours and are aware of the often asymptomatic nature and potential sequelae of chlamydia infection. PMID:20584287

Mixed infections with Chlamydia and porcine epidemic diarrhea virus - a new in vitro model of chlamydial persistence.

Science.gov (United States)

Borel, Nicole; Dumrese, Claudia; Ziegler, Urs; Schifferli, Andrea; Kaiser, Carmen; Pospischil, Andreas

2010-07-27

Chlamydiae induce persistent infections, which have been associated with a wide range of chronic diseases in humans and animals. Mixed infections with Chlamydia and porcine epidemic diarrhea virus (PEDV) may result in generation of persistent chlamydial infections. To test this hypothesis, an in vitro model of dual infection with cell culture-adapted PEDV and Chlamydia abortus or Chlamydia pecorum in Vero cells was established. Infected cultures were investigated by immunofluorescence (IF), transmission electron microscopy (TEM) and re-infection experiments. By IF, Chlamydia-infected cells showed normal inclusions after 39 hpi. Dual infections with Chlamydia abortus revealed a heterogenous mix of inclusion types including small inclusions consisting of aberrant bodies (ABs), medium-sized inclusions consisting of ABs and reticulate bodies and normal inclusions. Only aberrant inclusions were observable in dual infection experiments with Chlamydia pecorum and PEDV. TEM examinations of mixed infections with Chlamydia abortus and Chlamydia pecorum revealed aberrant chlamydial inclusions containing reticulate-like, pleomorphic ABs, which were up to 2 microm in diameter. No re-differentiation into elementary bodies (EBs) was detected. In re-infection experiments, co-infected cells produced fewer EBs than monoinfected cells. In the present study we confirm that PEDV co-infection alters the developmental cycle of member species of the family Chlamydiaceae, in a similar manner to other well-described persistence induction methods. Interestingly, this effect appears to be partially species-specific as Chlamydia pecorum appears more sensitive to PEDV co-infection than Chlamydia abortus, as evidenced by TEM and IF observations of a homogenous population of aberrant inclusions in PEDV - Chlamydia pecorum co-infections.

Incidence of Chlamydia trachomatis infections in the provinces of Novara and VCO: one year of observations

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Stefano Andreoni

2009-12-01

Full Text Available Chlamydia trachomatis infections represent the most common sexually transmitted diseases.The lack of growth of these microorganisms on common media and the roundabout research by immunofluorescence, has meant that, until now, these special-lived intracellular microorganisms have played a role probably underestimated in cases of infections affecting the sexual organs.The introduction of molecular biology has made possible their research in a much more simple, reliable and standardized methods. The study was carried out on endocervical samples, male urethral swabs and urine samples of men and women, determining the C. trachomatis DNA amplified using the BD ProbeTec ET system. This system uses technology SDA (Strand Displacement Amplification - Elongationcrowding of the blanks. The study was conducted from June 2008 to june 2009. Symptomatic and asyntptomatic patients residents in the provinces of Novara and the Verbano-Cusio-Ossola were considered. In this period 784 determinations were made in molecular biology. Chlamydia trachomatis was found in 26 cases equal to a percentage of 3.32%. While considering these preliminary data, however, we can estimate the rate of detection of C. trachomatis as a good starting point, because we have the impression that improved procedures particularly relate to the techniques for sampling and for storage and transport of the sample, can undoubtedly lead to much higher percentages.

The production of labelled gammaglobulin for the detection of chlamydia

International Nuclear Information System (INIS)

Popov, G.; Dimitrova, Zl.; Martinov, Sv.

1981-01-01

It was concluded that the main condition for the production of high titer labelled gammaglobulins was to obtain purified and concentrated Chlamydial antigens and use these with an adjuvant. To indicate Chlamydia in testing the conjugates it is essential to prepare standart test lamellas infected at high multiplicity of purified and concentrated Chlamydia. (authors)

Seroprevalence and genotype of Chlamydia in pet parrots in China.

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Zhang, N-Z; Zhang, X-X; Zhou, D-H; Huang, S-Y; Tian, W-P; Yang, Y-C; Zhao, Q; Zhu, X-Q

2015-01-01

Parrots are one of the most popular pet birds in China, and can harbour Chlamydia which has significance for human and animal health. We investigated, by indirect haemagglutination assay, the seroprevalence of Chlamydia infection in four species of parrots, namely budgerigars (Melopsittacus undulatus), lovebirds (Agapornis sp.), cockatiels (Nymphicus hollandicus) and Alexandrine parakeets (Psittacula eupatria) that were collected from Weifang and Beijing cities, North China and explored the association between potential risk factors and chlamydial seropositivity. We further determined the genotype of Chlamydia in 21 fresh faecal samples based on the ompA sequence by reconstruction of phylogenetic relationships. Of the 311 parrots examined, 35·37% (95% confidence interval 30·06-40·68) were seropositive, and species, gender, age, season and geographical location were identified as risk factors. Two PCR-positive samples represented Chlamydia psittaci genotype A. The occurrence of C. psittaci genotype A in the droppings of two pet parrots in China suggests potential environmental contamination with Chlamydiaceae and may raise a public health concern.

Inflammasome activation in ruminant cells infected with Chlamydia abortus

OpenAIRE

Doull, Laura Elizabeth

2016-01-01

Chlamydia abortus is the most common known infectious cause of ovine abortion worldwide but is rarely linked with bovine abortion. The reasons for this differential pathogenesis are unknown but may involve differences in innate immune recognition and immune responsiveness. This is supported by the observation that chlamydial abortion in sheep is associated with an inflammatory cytokine/chemokine cascade that is not commonly observed in cattle. Studies with other Chlamydia speci...

Golgi-associated Rab14, a new regulator for Chlamydia trachomatis infection outcome.

Science.gov (United States)

Capmany, Anahí; Leiva, Natalia; Damiani, María Teresa

2011-09-01

Chlamydia trachomatis is the causing agent of the most frequent bacterial sexually-transmitted diseases worldwide and is an underlying cause of chronic pelvic inflammatory diseases and cervical cancer. It is an obligate intracellular bacterium that establishes a close relationship with the Golgi complex and parasites the biosynthetic machinery of host cells. In a recent study, we have demonstrated that Rab14, a newly-described Golgi-associated Rab, is involved in the delivery of sphingolipids to the growing bacteria-containing vacuole. The interference with Rab14-controlled trafficking pathways delays chlamydial inclusion enlargement, decreases bacterial lipid uptake, negatively impact on bacterial differentiation, and reduces bacterial progeny and infectivity. C. trachomatis manipulation of host trafficking pathways for the acquisition of endogenously-biosynthesized nutrients arises as one of the characteristics of this highly evolved pathogen. The development of therapeutic strategies targeted to interfere with bacterium-host cell interaction is a new challenge for pharmacological approaches to control chlamydial infections.

CHLAMYDIA PNEUMONIAE INFECTION AND CARDIAC RISK FACTORS IN PATIENTS WITH MYOCARDIAL INFECTION

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Zohreh Azarkar

2011-03-01

Full Text Available BACKGROUND: Evidences support the possible involvement of microorganisms such as Chlamydia pneumonia in the pathogenesis of ischemic heart diseases through a chronic inflammatory process. The aim of this study was to determine the relation between Chlamydia pneumoniae seropositivity with acute myocardial infarction and its related risk factors.    METHODS: In this case-control study, 88 patients admitted in CCU with a diagnosis of acute coronary syndrome, without a history of chronic diseases including cancers were selected as cases and 49 surgical patients without an evidence of cardiovascular disease according to clinical examinations and ECG were selected as controls. Demographic characteristics and background risk factors were obtained using a questionnaire by expert nurses. Venous blood sample was obtained from participants for measuring the anti Chlamydia IgG and IgM antibodies using ELISA method. The prevalence of antibodies was compared in both groups and its relation with coronary syndrome was evaluated.    RESULTS: 88 and 49 patients were enrolled in case and control groups, respectively. Mean age of patients and the controls was 14 ± 59.7 and 13 ± 56.9 years, respectively (P = 0.26. Anti Chlamydia IgG seropositivity rate was 63(71.9% and 23(46.9% in case and controlcontrol groups, respectively (P < 0.01; OR: 2.85; CI 95%: 1.38 - 5.9. Anti Chlamydia IgM was positive in 1 patient and 1 control. Anti Chlamydia IgG seropositivity rate was higher in patients older than 50 years old than those younger than 50 years old (OR: 2.83; CI 95%: 1.31 -1.14. There was a significant relation between BMI, smoking and Anti Chlamydia IgG seropositivity.    CONCLUSION: Considering the relation between anti Chlamydia antibody IgG seropositivity with BMI and myocardial infarction, it seems that appropriate diagnosis and treatment of these prone patients can be benefical.

Topological analysis of Chlamydia trachomatis L2 outer membrane protein 2

DEFF Research Database (Denmark)

Mygind, P; Christiansen, Gunna; Birkelund, Svend

1998-01-01

Using monospecific polyclonal antisera to different parts of Chlamydia trachomatis L2 outer membrane protein 2 (Omp2), we show that the protein is localized at the inner surface of the outer membrane. Omp2 becomes immunoaccessible when Chlamydia elementary bodies are treated with dithiothreitol...

Mixed infections with Chlamydia and porcine epidemic diarrhea virus - a new in vitro model of chlamydial persistence

Directory of Open Access Journals (Sweden)

Kaiser Carmen

2010-07-01

Full Text Available Abstract Background Chlamydiae induce persistent infections, which have been associated with a wide range of chronic diseases in humans and animals. Mixed infections with Chlamydia and porcine epidemic diarrhea virus (PEDV may result in generation of persistent chlamydial infections. To test this hypothesis, an in vitro model of dual infection with cell culture-adapted PEDV and Chlamydia abortus or Chlamydia pecorum in Vero cells was established. Results Infected cultures were investigated by immunofluorescence (IF, transmission electron microscopy (TEM and re-infection experiments. By IF, Chlamydia-infected cells showed normal inclusions after 39 hpi. Dual infections with Chlamydia abortus revealed a heterogenous mix of inclusion types including small inclusions consisting of aberrant bodies (ABs, medium-sized inclusions consisting of ABs and reticulate bodies and normal inclusions. Only aberrant inclusions were observable in dual infection experiments with Chlamydia pecorum and PEDV. TEM examinations of mixed infections with Chlamydia abortus and Chlamydia pecorum revealed aberrant chlamydial inclusions containing reticulate-like, pleomorphic ABs, which were up to 2 μm in diameter. No re-differentiation into elementary bodies (EBs was detected. In re-infection experiments, co-infected cells produced fewer EBs than monoinfected cells. Conclusions In the present study we confirm that PEDV co-infection alters the developmental cycle of member species of the family Chlamydiaceae, in a similar manner to other well-described persistence induction methods. Interestingly, this effect appears to be partially species-specific as Chlamydia pecorum appears more sensitive to PEDV co-infection than Chlamydia abortus, as evidenced by TEM and IF observations of a homogenous population of aberrant inclusions in PEDV - Chlamydia pecorum co-infections.

Increase of Intracellular Cyclic AMP by PDE4 Inhibitors Affects HepG2 Cell Cycle Progression and Survival.

Science.gov (United States)

Massimi, Mara; Cardarelli, Silvia; Galli, Francesca; Giardi, Maria Federica; Ragusa, Federica; Panera, Nadia; Cinque, Benedetta; Cifone, Maria Grazia; Biagioni, Stefano; Giorgi, Mauro

2017-06-01

Type 4 cyclic nucleotide phosphodiesterases (PDE4) are major members of a superfamily of enzymes (PDE) involved in modulation of intracellular signaling mediated by cAMP. Broadly expressed in most human tissues and present in large amounts in the liver, PDEs have in the last decade been key therapeutic targets for several inflammatory diseases. Recently, a significant body of work has underscored their involvement in different kinds of cancer, but with no attention paid to liver cancer. The present study investigated the effects of two PDE4 inhibitors, rolipram and DC-TA-46, on the growth of human hepatoma HepG2 cells. Treatment with these inhibitors caused a marked increase of intracellular cAMP level and a dose- and time-dependent effect on cell growth. The concentrations of inhibitors that halved cell proliferation to about 50% were used for cell cycle experiments. Rolipram (10 μM) and DC-TA-46 (0.5 μM) produced a decrease of cyclin expression, in particular of cyclin A, as well as an increase in p21, p27 and p53, as evaluated by Western blot analysis. Changes in the intracellular localization of cyclin D1 were also observed after treatments. In addition, both inhibitors caused apoptosis, as demonstrated by an Annexin-V cytofluorimetric assay and analysis of caspase-3/7 activity. Results demonstrated that treatment with PDE4 inhibitors affected HepG2 cell cycle and survival, suggesting that they might be useful as potential adjuvant, chemotherapeutic or chemopreventive agents in hepatocellular carcinoma. J. Cell. Biochem. 118: 1401-1411, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Seroprevalence and risk factors of Chlamydia abortus infection in free-ranging white yaks in China

OpenAIRE

Qin, Si-Yuan; Huang, Si-Yang; Yin, Ming-Yang; Tan, Qi-Dong; Liu, Guang-Xue; Zhou, Dong-Hui; Zhu, Xing-Quan; Zhou, Ji-Zhang; Qian, Ai-Dong

2015-01-01

Background Chlamydia is gram-negative obligate bacteria which causes a wide variety of diseases in humans and animals. To date, there are a few reports about the seroprevalence of Chlamydia and the risk factors associated with Chlamydia infection in yaks in the world. In this study, 974 blood samples were collected from white yaks (Bos grunniens) in Tianzhu Tibetan Autonomous County, Gansu province, northwest China from June 2013 to April 2014. Results Antibodies against Chlamydia abortus wer...

Evaluation of the microparticle enzyme immunoassay Abbott IMx Select Chlamydia and the importance of urethral site sampling to detect Chlamydia trachomatis in women.

OpenAIRE

Brokenshire, M K; Say, P J; van Vonno, A H; Wong, C

1997-01-01

OBJECTIVE: To evaluate the commercial microparticle enzyme immunoassay (MEIA), Abbott IMx Select Chlamydia, for the detection of Chlamydia trachomatis in women and to compare its performance with endocervical cell culture. Also, to determine whether sampling the urethral site is an important part of chlamydial diagnosis in women. SETTING: The Auckland, Manukau, and Waitakere Sexual Health Clinics, Auckland, New Zealand and the Department of Clinical Microbiology, Auckland Hospital, Auckland, ...

NNDSS - Table II. Chlamydia to Coccidioidomycosis

Data.gov (United States)

U.S. Department of Health & Human Services — NNDSS - Table II. Chlamydia to Coccidioidomycosis - 2017. In this Table, provisional cases of selected notifiable diseases (≥1,000 cases reported during the...

NNDSS - Table II. Chlamydia to Coccidioidomycosis

Data.gov (United States)

U.S. Department of Health & Human Services — NNDSS - Table II. Chlamydia to Coccidioidomycosis - 2016. In this Table, provisional* cases of selected† notifiable diseases (≥1,000 cases reported during the...

Evidence for Chlamydia in wild mammals of the Serengeti.

Science.gov (United States)

Pospischil, Andreas; Kaiser, Carmen; Hofmann-Lehmann, Regina; Lutz, Hans; Hilbe, Monika; Vaughan, Lloyd; Borel, Nicole

2012-10-01

Only limited information is available on the presence of Chlamydiaceae in wildlife, a deficit that is particularly acute concerning mammalian wildlife in Africa. In a retrospective analysis of organ material from an earlier study on wild mammals from the Seregenti National Park, 521 samples from 54 animals of 14 mammalian species were investigated. The presence of Chlamydiaceae was analyzed using molecular methods and immunohistochemistry. Chlamydial DNA was detected by real-time polymerase chain reaction in formalin-fixed and paraffin-embedded tissues from large ruminants (African buffaloes, Syncerus caffer, n=4) and a large predator (spotted hyena, Crocuta crocuta, n=1). Microarray results revealed Chlamydia abortus in all cases, confirmed by sequencing of selected samples, and a mixed infection with Chlamydia abortus and Chlamydia pneumoniae in an African buffalo. This is the first report of Chlamydiaceae in African wildlife of the Serengeti area.

Chlamydia trachomatis Mip-like protein

DEFF Research Database (Denmark)

Lundemose, AG; Rousch, DA; Birkelund, Svend

1992-01-01

A 27 kDa Chlamydia trachomatis Mip-like protein with homology of a 175-amino-acid C-terminal fragment to the surface-exposed Legionella pneumophila mip-gene product has previously been described. In this paper the entire chlamydia Mip-like sequence of C. trachomatis serovar L2 (lymphogranuloma...... venereum (LGV) biovar) is presented. The sequence shows high similarity to the legionella Mip protein and its C-terminal region, like that of the legionella Mip, has high amino acid similarity to eukaryotic and prokaryotic FK506-binding proteins. The chlamydial mip-like gene was detected by polymerase...... chain reaction (PCR) in other C. trachomatis serovars and by sequencing of the mip-like genes of serovars B and E (trachoma biovar) was shown to be highly conserved within the two major biovars of C. trachomatis. Monoclonal and polyclonal antibodies raised against the recombinant Mip-like protein failed...

Molecular prevalence and genotyping of Chlamydia spp. in wild birds from South Korea.

Science.gov (United States)

Jeong, Jipseol; An, Injung; Oem, Jae-Ku; Wang, Seung-Jun; Kim, Yongkwan; Shin, Jeong-Hwa; Woo, Chanjin; Kim, Youngsik; Jo, Seong-Deok; Son, Kidong; Lee, Saemi; Jheong, Weonhwa

2017-07-07

Wild birds are reservoirs for Chlamydia spp. Of the total 225 samples from wild birds during January to September 2016 in Korea, 4 (1.8%) and 2 (0.9%) showed positive for Chlamydia psittaci and Chlamydia gallinacea, respectively. Phylogenetic analyses and comparisons of sequence identities for outer-membrane protein A (ompA) revealed that Korean C. psittaci fall into three previously known genotypes; genotype E, 1V and 6N, whereas the Korean C. gallinacea were classified as new variants of C. gallinacea. Our study demonstrates that wild birds in South Korea carry at least two Chlamydia species: C. psittaci and C. gallinacea, and provides new information on the epidemiology of avian chlamydiosis in wild birds.

Intracellularly Induced Cyclophilins Play an Important Role in Stress Adaptation and Virulence of Brucella abortus

Science.gov (United States)

García Fernández, Lucía; DelVecchio, Vito G.; Briones, Gabriel

2013-01-01

Brucella is an intracellular bacterial pathogen that causes the worldwide zoonotic disease brucellosis. Brucella virulence relies on its ability to transition to an intracellular lifestyle within host cells. Thus, this pathogen must sense its intracellular localization and then reprogram gene expression for survival within the host cell. A comparative proteomic investigation was performed to identify differentially expressed proteins potentially relevant for Brucella intracellular adaptation. Two proteins identified as cyclophilins (CypA and CypB) were overexpressed in the intracellular environment of the host cell in comparison to laboratory-grown Brucella. To define the potential role of cyclophilins in Brucella virulence, a double-deletion mutant was constructed and its resulting phenotype was characterized. The Brucella abortus ΔcypAB mutant displayed increased sensitivity to environmental stressors, such as oxidative stress, pH, and detergents. In addition, the B. abortus ΔcypAB mutant strain had a reduced growth rate at lower temperature, a phenotype associated with defective expression of cyclophilins in other microorganisms. The B. abortus ΔcypAB mutant also displays reduced virulence in BALB/c mice and defective intracellular survival in HeLa cells. These findings suggest that cyclophilins are important for Brucella virulence and survival in the host cells. PMID:23230297

Metabolic features of Protochlamydia amoebophila elementary bodies--a link between activity and infectivity in Chlamydiae.

Directory of Open Access Journals (Sweden)

Barbara S Sixt

Full Text Available The Chlamydiae are a highly successful group of obligate intracellular bacteria, whose members are remarkably diverse, ranging from major pathogens of humans and animals to symbionts of ubiquitous protozoa. While their infective developmental stage, the elementary body (EB, has long been accepted to be completely metabolically inert, it has recently been shown to sustain some activities, including uptake of amino acids and protein biosynthesis. In the current study, we performed an in-depth characterization of the metabolic capabilities of EBs of the amoeba symbiont Protochlamydia amoebophila. A combined metabolomics approach, including fluorescence microscopy-based assays, isotope-ratio mass spectrometry (IRMS, ion cyclotron resonance Fourier transform mass spectrometry (ICR/FT-MS, and ultra-performance liquid chromatography mass spectrometry (UPLC-MS was conducted, with a particular focus on the central carbon metabolism. In addition, the effect of nutrient deprivation on chlamydial infectivity was analyzed. Our investigations revealed that host-free P. amoebophila EBs maintain respiratory activity and metabolize D-glucose, including substrate uptake as well as host-free synthesis of labeled metabolites and release of labeled CO2 from (13C-labeled D-glucose. The pentose phosphate pathway was identified as major route of D-glucose catabolism and host-independent activity of the tricarboxylic acid (TCA cycle was observed. Our data strongly suggest anabolic reactions in P. amoebophila EBs and demonstrate that under the applied conditions D-glucose availability is essential to sustain metabolic activity. Replacement of this substrate by L-glucose, a non-metabolizable sugar, led to a rapid decline in the number of infectious particles. Likewise, infectivity of Chlamydia trachomatis, a major human pathogen, also declined more rapidly in the absence of nutrients. Collectively, these findings demonstrate that D-glucose is utilized by P. amoebophila

NNDSS - Table II. Chlamydia to Coccidioidomycosis

Data.gov (United States)

U.S. Department of Health & Human Services — NNDSS - Table II. Chlamydia to Coccidioidomycosis - 2015.In this Table, provisional cases of selected notifiable diseases (≥1,000 cases reported during the preceding...

RNA interference screen identifies Abl kinase and PDGFR signaling in Chlamydia trachomatis entry.

Directory of Open Access Journals (Sweden)

Cherilyn A Elwell

2008-03-01

Full Text Available The strain designated Chlamydia trachomatis serovar L2 that was used for experiments in this paper is Chlamydia muridarum, a species closely related to C. trachomatis (and formerly termed the Mouse Pneumonitis strain of C. trachomatis. This conclusion was verified by deep sequencing and by PCR using species-specific primers. All data presented in the results section that refer to C. trachomatis should be interpreted as referring to C. muridarum. Since C. muridarum TARP lacks the consensus tyrosine repeats present in C. trachomatis TARP, we cannot make any conclusions about the role of TARP phosphorylation and C. muridarum entry. However, the conclusion that C. trachomatis L2 TARP is a target of Abl kinase is still valid as these experiments were performed with C. trachomatis L2 TARP [corrected]. To elucidate the mechanisms involved in early events in Chlamydia trachomatis infection, we conducted a large scale unbiased RNA interference screen in Drosophila melanogaster S2 cells. This allowed identification of candidate host factors in a simple non-redundant, genetically tractable system. From a library of 7,216 double stranded RNAs (dsRNA, we identified approximately 226 host genes, including two tyrosine kinases, Abelson (Abl kinase and PDGF- and VEGF-receptor related (Pvr, a homolog of the Platelet-derived growth factor receptor (PDGFR. We further examined the role of these two kinases in C. trachomatis binding and internalization into mammalian cells. Both kinases are phosphorylated upon infection and recruited to the site of bacterial attachment, but their roles in the infectious process are distinct. We provide evidence that PDGFRbeta may function as a receptor, as inhibition of PDGFRbeta by RNA interference or by PDGFRbeta neutralizing antibodies significantly reduces bacterial binding, whereas depletion of Abl kinase has no effect on binding. Bacterial internalization can occur through activation of PDGFRbeta or through independent

A cross sectional study on Dutch layer farms to investigate the prevalence and potential risk factors for different Chlamydia species.

NARCIS (Netherlands)

Heijne, Marloes; van der Goot, Jeanet A; Fijten, Helmi; van der Giessen, Joke W; Kuijt, Eric; Maassen, Catharina B M; van Roon, Annika; Wit, Ben; Koets, Ad P; Roest, Hendrik I J

2018-01-01

In poultry several Chlamydia species have been detected, but Chlamydia psittaci and Chlamydia gallinacea appear to be most prevalent and important. Chlamydia psittaci is a well-known zoonosis and is considered to be a pathogen of poultry. Chlamydia gallinacea has been described more recently. Its

A cross sectional study on Dutch layer farms to investigate the prevalence and potential risk factors for different Chlamydia species

NARCIS (Netherlands)

Heijne, Marloes; Goot, van der Jeanet A.; Fijten, Helmi; Giessen, van der Joke W.; Kuijt, Eric; Maassen, Catharina B.M.; Roon, van Annika; Wit, Ben; Koets, Ad P.; Roest, Hendrik I.J.

2018-01-01

In poultry several Chlamydia species have been detected, but Chlamydia psittaci and Chlamydia gallinacea appear to be most prevalent and important. Chlamydia psittaci is a well-known zoonosis and is considered to be a pathogen of poultry. Chlamydia gallinacea has been described more recently. Its

The prevalence of Chlamydia trachomatis infection in Australia: a systematic review and meta-analysis

Directory of Open Access Journals (Sweden)

Lewis Dyani

2012-05-01

Full Text Available Abstract Background Chlamydia trachomatis is a common sexually transmitted infection in Australia. This report aims to measure the burden of chlamydia infection by systematically reviewing reports on prevalence in Australian populations. Methods Electronic databases and conference websites were searched from 1997–2011 using the terms ‘Chlamydia trachomatis’ OR ‘chlamydia’ AND ‘prevalence’ OR ‘epidemiology’ AND ‘Australia’. Reference lists were checked and researchers contacted for additional literature. Studies were categorised by setting and participants, and meta-analysis conducted to determine pooled prevalence estimates for each category. Results Seventy-six studies met the inclusion criteria for the review. There was a high level of heterogeneity between studies; however, there was a trend towards higher chlamydia prevalence in younger populations, Indigenous Australians, and those attending sexual health centres. In community or general practice settings, pooled prevalence for women Conclusions Chlamydia trachomatis infections are a significant health burden in Australia; however, accurate estimation of chlamydia prevalence in Australian sub-populations is limited by heterogeneity within surveyed populations, and variations in sampling methodologies and data reporting. There is a need for more large, population-based studies and prospective cohort studies to compliment mandatory notification data.

Diagnostic Procedures to Detect Chlamydia trachomatis Infections

Directory of Open Access Journals (Sweden)

Thomas Meyer

2016-08-01

Full Text Available The intracellular life style of chlamydia and the ability to cause persistent infections with low-grade replication requires tests with high analytical sensitivity to directly detect C. trachomatis (CT in medical samples. Nucleic acid amplification tests (NAATs are the most sensitive assays with a specificity similar to cell culture and are considered the method of choice for CT detection. In addition, NAATs can be performed on various clinical specimens that do not depend on specific transport and storage conditions, since NAATs do not require infectious bacteria. In the case of lower genital tract infections, first void urine and vaginal swabs are the recommended specimens for testing males and females, respectively. Infections of anorectal, oropharyngeal and ocular epithelia should also be tested by NAAT analysis of corresponding mucosal swabs. In particular, anorectal infections of men who have sex with men (MSM should include evaluation of lymphogranuloma venereum (LGV by identification of genotypes L1, L2 or L3. Detection of CT antigens by enzyme immunoassay (EIAs or rapid diagnostic tests (RDTs are unsuitable due to insufficient sensitivity and specificity. Recent PCR-based RDTs, however, are non-inferior to standard NAATs, and might be used at the point-of-care. Serology finds application in the diagnostic work-up of suspected chronic CT infection but is inappropriate to diagnose acute infections.

Primary endosymbiosis: have cyanobacteria and Chlamydiae ever been roommates?

Directory of Open Access Journals (Sweden)

Philippe Deschamps

2014-12-01

Full Text Available Eukaryotes acquired the ability to process photosynthesis by engulfing a cyanobacterium and transforming it into a genuine organelle called the plastid. This event, named primary endosymbiosis, occurred once more than a billion years ago, and allowed the emergence of the Archaeplastida, a monophyletic supergroup comprising the green algae and plants, the red algae and the glaucophytes. Of the other known cases of symbiosis between cyanobacteria and eukaryotes, none has achieved a comparable level of cell integration nor reached the same evolutionary and ecological success than primary endosymbiosis did. Reasons for this unique accomplishment are still unknown and difficult to comprehend. The exploration of plant genomes has revealed a considerable amount of genes closely related to homologs of Chlamydiae bacteria, and probably acquired by horizontal gene transfer. Several studies have proposed that these transferred genes, which are mostly involved in the functioning of the plastid, may have helped the settlement of primary endosymbiosis. Some of these studies propose that Chlamydiae and cyanobacterial symbionts coexisted in the eukaryotic host of the primary endosymbiosis, and that Chlamydiae provided solutions for the metabolic symbiosis between the cyanobacterium and the host, ensuring the success of primary endosymbiosis. In this review, I present a reevaluation of the contribution of Chlamydiae genes to the genome of Archaeplastida and discuss the strengths and weaknesses of this tripartite model for primary endosymbiosis.

Pneumonia due to Chlamydia pecorum in a Koala (Phascolarctos cinereus).

Science.gov (United States)

Mackie, J T; Gillett, A K; Palmieri, C; Feng, T; Higgins, D P

2016-11-01

Chlamydiosis is a common infectious disease of koalas (Phascolarctos cinereus), but Chlamydia spp. have not yet been demonstrated to cause pneumonia in these animals. A juvenile male koala died following an episode of respiratory disease. At necropsy examination, the lung tissue was consolidated. Microscopical lesions in the lung included pyogranulomatous bronchopneumonia, proliferation of bronchiolar and alveolar epithelium and interstitial fibrosis. Hyperplastic bronchiolar epithelial cells contained aggregates of small basophilic punctate organisms, which were confirmed as chlamydiae by transmission electron microscopy and immunohistochemistry. Real-time polymerase chain reaction identified these as Chlamydia pecorum. This report provides the best evidence to date of chlamydial infection causing pneumonia in a koala, and the first evidence that C. pecorum is capable of infecting the bronchiolar epithelium of the koala. Copyright © 2016 Elsevier Ltd. All rights reserved.

Metabolic Features of Protochlamydia amoebophila Elementary Bodies – A Link between Activity and Infectivity in Chlamydiae

Science.gov (United States)

Watzka, Margarete; Wultsch, Anna; Tziotis, Dimitrios; Montanaro, Jacqueline; Richter, Andreas; Schmitt-Kopplin, Philippe; Horn, Matthias

2013-01-01

The Chlamydiae are a highly successful group of obligate intracellular bacteria, whose members are remarkably diverse, ranging from major pathogens of humans and animals to symbionts of ubiquitous protozoa. While their infective developmental stage, the elementary body (EB), has long been accepted to be completely metabolically inert, it has recently been shown to sustain some activities, including uptake of amino acids and protein biosynthesis. In the current study, we performed an in-depth characterization of the metabolic capabilities of EBs of the amoeba symbiont Protochlamydia amoebophila. A combined metabolomics approach, including fluorescence microscopy-based assays, isotope-ratio mass spectrometry (IRMS), ion cyclotron resonance Fourier transform mass spectrometry (ICR/FT-MS), and ultra-performance liquid chromatography mass spectrometry (UPLC-MS) was conducted, with a particular focus on the central carbon metabolism. In addition, the effect of nutrient deprivation on chlamydial infectivity was analyzed. Our investigations revealed that host-free P. amoebophila EBs maintain respiratory activity and metabolize D-glucose, including substrate uptake as well as host-free synthesis of labeled metabolites and release of labeled CO2 from 13C-labeled D-glucose. The pentose phosphate pathway was identified as major route of D-glucose catabolism and host-independent activity of the tricarboxylic acid (TCA) cycle was observed. Our data strongly suggest anabolic reactions in P. amoebophila EBs and demonstrate that under the applied conditions D-glucose availability is essential to sustain metabolic activity. Replacement of this substrate by L-glucose, a non-metabolizable sugar, led to a rapid decline in the number of infectious particles. Likewise, infectivity of Chlamydia trachomatis, a major human pathogen, also declined more rapidly in the absence of nutrients. Collectively, these findings demonstrate that D-glucose is utilized by P. amoebophila EBs and provide

Chemical cross-linking of Chlamydia trachomatis

DEFF Research Database (Denmark)

Birkelund, Svend; Lundemose, AG; Christiansen, Gunna

1988-01-01

Purified elementary bodies (EBs) of Chlamydia trachomatis serovar L2 were analyzed by chemical cross-linking with disuccinimidyl selenodipropionate. The effect of the cross-linking was analyzed by immunoblotting sodium dodecyl sulfate-polyacrylamide gel electrophoresis-separated components which...

CHLAMYDIA TRACHOMATIS IgG ANTIBODIES

African Journals Online (AJOL)

2014-12-31

Dec 31, 2014 ... humans caused by the bacterium Chlamydia trachomatis. .... more people were living inside the school hostel in FCETU (45; 45.0%) .... seroprevalence than their counterparts with less risky behaviours ..... Janet S.B, Stephen A.M. Medical Microbiology 24th Edition, The McGraw-Hill Companies, Inc. USA, ...

The Type III Secretion System-Related CPn0809 from Chlamydia pneumoniae.

Directory of Open Access Journals (Sweden)

Astrid C Engel

Full Text Available Chlamydia pneumoniae is an intracellular Gram-negative bacterium that possesses a type III secretion system (T3SS, which enables the pathogen to deliver, in a single step, effector proteins for modulation of host-cell functions into the human host cell cytosol to establish a unique intracellular niche for replication. The translocon proteins located at the top of the T3SS needle filament are essential for its function, as they form pores in the host-cell membrane. Interestingly, unlike other Gram-negative bacteria, C. pneumoniae has two putative translocon operons, named LcrH_1 and LcrH_2. However, little is known about chlamydial translocon proteins. In this study, we analyzed CPn0809, one of the putative hydrophobic translocators encoded by the LcrH_1 operon, and identified an 'SseC-like family' domain characteristic of T3S translocators. Using bright-field and confocal microscopy, we found that CPn0809 is associated with EBs during early and very late phases of a C. pneumoniae infection. Furthermore, CPn0809 forms oligomers, and interacts with the T3SS chaperone LcrH_1, via its N-terminal segment. Moreover, expression of full-length CPn0809 in the heterologous host Escherichia coli causes a grave cytotoxic effect that leads to cell death. Taken together, our data indicate that CPn0809 likely represents one of the translocon proteins of the C. pneumoniae T3SS, and possibly plays a role in the translocation of effector proteins in the early stages of infection.

High-resolution typing of Chlamydia trachomatis: epidemiological and clinical uses.

Science.gov (United States)

de Vries, Henry J C; Schim van der Loeff, Maarten F; Bruisten, Sylvia M

2015-02-01

A state-of-the-art overview of molecular Chlamydia trachomatis typing methods that are used for routine diagnostics and scientific studies. Molecular epidemiology uses high-resolution typing techniques such as multilocus sequence typing, multilocus variable number of tandem repeats analysis, and whole-genome sequencing to identify strains based on their DNA sequence. These data can be used for cluster, network and phylogenetic analyses, and are used to unveil transmission networks, risk groups, and evolutionary pathways. High-resolution typing of C. trachomatis strains is applied to monitor treatment efficacy and re-infections, and to study the recent emergence of lymphogranuloma venereum (LGV) amongst men who have sex with men in high-income countries. Chlamydia strain typing has clinical relevance in disease management, as LGV needs longer treatment than non-LGV C. trachomatis. It has also led to the discovery of a new variant Chlamydia strain in Sweden, which was not detected by some commercial C. trachomatis diagnostic platforms. After a brief history and comparison of the various Chlamydia typing methods, the applications of the current techniques are described and future endeavors to extend scientific understanding are formulated. High-resolution typing will likely help to further unravel the pathophysiological mechanisms behind the wide clinical spectrum of chlamydial disease.

Promoting chlamydia screening with posters and leaflets in general practice--a qualitative study.

Science.gov (United States)

Freeman, Elaine; Howell-Jones, Rebecca; Oliver, Isabel; Randall, Sarah; Ford-Young, William; Beckwith, Philippa; McNulty, Cliodna

2009-10-12

General practice staff are reluctant to discuss sexual health opportunistically in all consultations. Health promotion materials may help alleviate this barrier. Chlamydia screening promotion posters and leaflets, produced by the English National Chlamydia Screening Programme (NCSP), have been available to general practices, through local chlamydia screening offices, since its launch. In this study we explored the attitudes of general practice staff to these screening promotional materials, how they used them, and explored other promotional strategies to encourage chlamydia screening. Twenty-five general practices with a range of screening rates, were purposively selected from six NCSP areas in England. In focus groups doctors, nurses, administrative staff and receptionists were encouraged to discuss candidly their experiences about their use and opinions of posters, leaflets and advertising to promote chlamydia screening. Researchers observed whether posters and leaflets were on display in reception and/or waiting areas. Data were collected and analysed concurrently using a stepwise framework analytical approach. Although two-thirds of screening practices reported that they displayed posters and leaflets, they were not prominently displayed in most practices. Only a minority of practices reported actively using screening promotional materials on an ongoing basis. Most staff in all practices were not following up the advertising in posters and leaflets by routinely offering opportunistic screening to their target population. Some staff in many practices thought posters and leaflets would cause offence or embarrassment to their patients. Distribution of chlamydia leaflets by receptionists was thought to be inappropriate by some practices, as they thought patients would be offended when being offered a leaflet in a public area. Practice staff suggested the development of pocket-sized leaflets. The NCSP should consider developing a range of more discrete but eye

Promoting chlamydia screening with posters and leaflets in general practice - a qualitative study

Science.gov (United States)

Freeman, Elaine; Howell-Jones, Rebecca; Oliver, Isabel; Randall, Sarah; Ford-Young, William; Beckwith, Philippa; McNulty, Cliodna

2009-01-01

Background General practice staff are reluctant to discuss sexual health opportunistically in all consultations. Health promotion materials may help alleviate this barrier. Chlamydia screening promotion posters and leaflets, produced by the English National Chlamydia Screening Programme (NCSP), have been available to general practices, through local chlamydia screening offices, since its launch. In this study we explored the attitudes of general practice staff to these screening promotional materials, how they used them, and explored other promotional strategies to encourage chlamydia screening. Methods Twenty-five general practices with a range of screening rates, were purposively selected from six NCSP areas in England. In focus groups doctors, nurses, administrative staff and receptionists were encouraged to discuss candidly their experiences about their use and opinions of posters, leaflets and advertising to promote chlamydia screening. Researchers observed whether posters and leaflets were on display in reception and/or waiting areas. Data were collected and analysed concurrently using a stepwise framework analytical approach. Results Although two-thirds of screening practices reported that they displayed posters and leaflets, they were not prominently displayed in most practices. Only a minority of practices reported actively using screening promotional materials on an ongoing basis. Most staff in all practices were not following up the advertising in posters and leaflets by routinely offering opportunistic screening to their target population. Some staff in many practices thought posters and leaflets would cause offence or embarrassment to their patients. Distribution of chlamydia leaflets by receptionists was thought to be inappropriate by some practices, as they thought patients would be offended when being offered a leaflet in a public area. Practice staff suggested the development of pocket-sized leaflets. Conclusion The NCSP should consider developing

Promoting chlamydia screening with posters and leaflets in general practice - a qualitative study

Directory of Open Access Journals (Sweden)

Ford-Young William

2009-10-01

Full Text Available Abstract Background General practice staff are reluctant to discuss sexual health opportunistically in all consultations. Health promotion materials may help alleviate this barrier. Chlamydia screening promotion posters and leaflets, produced by the English National Chlamydia Screening Programme (NCSP, have been available to general practices, through local chlamydia screening offices, since its launch. In this study we explored the attitudes of general practice staff to these screening promotional materials, how they used them, and explored other promotional strategies to encourage chlamydia screening. Methods Twenty-five general practices with a range of screening rates, were purposively selected from six NCSP areas in England. In focus groups doctors, nurses, administrative staff and receptionists were encouraged to discuss candidly their experiences about their use and opinions of posters, leaflets and advertising to promote chlamydia screening. Researchers observed whether posters and leaflets were on display in reception and/or waiting areas. Data were collected and analysed concurrently using a stepwise framework analytical approach. Results Although two-thirds of screening practices reported that they displayed posters and leaflets, they were not prominently displayed in most practices. Only a minority of practices reported actively using screening promotional materials on an ongoing basis. Most staff in all practices were not following up the advertising in posters and leaflets by routinely offering opportunistic screening to their target population. Some staff in many practices thought posters and leaflets would cause offence or embarrassment to their patients. Distribution of chlamydia leaflets by receptionists was thought to be inappropriate by some practices, as they thought patients would be offended when being offered a leaflet in a public area. Practice staff suggested the development of pocket-sized leaflets. Conclusion The NCSP

Attitudes to Chlamydia screening elicited using the social networking site Facebook for subject recruitment.

Science.gov (United States)

Ahmed, Navera; Jayasinghe, Yasmin; Wark, John D; Fenner, Yeshe; Moore, Elya E; Tabrizi, Sepehr N; Fletcher, Ashley; Garland, Suzanne M

2013-07-01

Chlamydia (Chlamydia trachomatis) is the commonest bacterial sexually transmissible infection worldwide and contributes to significant morbidity in females. We examined potential barriers and facilitating factors for screening in young Victorian women, using the social networking site, Facebook to recruit participants. This was part of a larger study on young women's health that assessed the feasibility of using social networking sites for recruitment. An advertisement was placed on Facebook between May and September 2010, and was visible to eligible women. Women who clicked on the advertisement and expressed their interest in participating were invited to complete a questionnaire either at a study site or online. In total, 278 participants completed the survey, with 76% reporting willingness to participate in chlamydia screening by recruitment via an online system. Overall, 73% of participants indicated they were comfortable providing a urine sample collected at home for chlamydia screening, with older participants less comfortable with this method (P=0.02, odds ratio (OR)=0.09, 95% confidence interval (CI)=0.01-0.7). Participants expressed comfort with their Pap smear and chlamydia screening being performed together (92.7%), especially those who were aware of human papillomavirus (P<0.01, OR=2.5, 95% CI=1.3-4.7). This study demonstrated willingness by young Victorian women using Facebook to participate in screening for chlamydia. There was strong acceptance of self-collected sampling, and of combined chlamydia and cervical cytology screening. Facebook may therefore be a feasible way for improving screening coverage at a population level.

A docking study of enhanced intracellular survival protein from Mycobacterium tuberculosis with human DUSP16/MKP-7

International Nuclear Information System (INIS)

Yoon, Hye-Jin; Kim, Kyoung Hoon; Yang, Jin Kuk; Suh, Se Won; Kim, Hyunsik; Jang, Soonmin

2013-01-01

A docking study of Mtb Eis with its substrate DUSP16/MKP-7 was performed. The docking model suggests dissociation of hexameric Mtb Eis into dimers or monomers. The intracellular pathogen Mycobacterium tuberculosis (Mtb) causes tuberculosis, and one of its secreted effector proteins, called enhanced intracellular survival (Eis) protein, enhances its survival in macrophages. Mtb Eis activates JNK-specific dual-specificity protein phosphatase 16 (DUSP16)/mitogen-activated protein kinase phosphatase-7 (MKP-7) through the acetylation on Lys55, thus inactivating JNK by dephosphorylation. Based on the recently reported crystal structure of Mtb Eis, a docking model for the binding of Mtb Eis to DUSP16/MKP-7 was generated. In the docking model, the substrate helix containing Lys55 of DUSP16/MKP-7 fits nicely into the active-site cleft of Mtb Eis; the twisted β-sheet of Eis domain II embraces the substrate helix from one side. Most importantly, the side-chain of Lys55 is inserted toward acetyl-CoA and the resulting distance is 4.6 Å between the NZ atom of Lys55 and the carbonyl carbon of the acetyl group in acetyl-CoA. The binding of Mtb Eis and DUSP16/MKP-7 is maintained by strong electrostatic interactions. The active-site cleft of Mtb Eis has a negatively charged surface formed by Asp25, Glu138, Asp286, Glu395 and the terminal carboxylic group of Phe396. In contrast, DUSP16/MKP-7 contains five basic residues, Lys52, Lys55, Arg56, Arg57 and Lys62, which point toward the negatively charged surface of the active-site pocket of Mtb Eis. Thus, the current docking model suggests that the binding of DUSP16/MKP-7 to Mtb Eis should be established by charge complementarity in addition to a very favorable geometric arrangement. The suggested mode of binding requires the dissociation of the hexameric Mtb Eis into dimers or monomers. This study may be useful for future studies aiming to develop inhibitors of Mtb Eis as a new anti-tuberculosis drug candidate

A docking study of enhanced intracellular survival protein from Mycobacterium tuberculosis with human DUSP16/MKP-7

Energy Technology Data Exchange (ETDEWEB)

Yoon, Hye-Jin, E-mail: yoonhj@snu.ac.kr; Kim, Kyoung Hoon [Seoul National University, Seoul 151-747 (Korea, Republic of); Yang, Jin Kuk [Soongsil University, Seoul 156-743 (Korea, Republic of); Suh, Se Won [Seoul National University, Seoul 151-747 (Korea, Republic of); Seoul National University, Seoul 151-747 (Korea, Republic of); Kim, Hyunsik; Jang, Soonmin, E-mail: yoonhj@snu.ac.kr [Sejong University, Seoul 143-747 (Korea, Republic of)

2013-11-01

A docking study of Mtb Eis with its substrate DUSP16/MKP-7 was performed. The docking model suggests dissociation of hexameric Mtb Eis into dimers or monomers. The intracellular pathogen Mycobacterium tuberculosis (Mtb) causes tuberculosis, and one of its secreted effector proteins, called enhanced intracellular survival (Eis) protein, enhances its survival in macrophages. Mtb Eis activates JNK-specific dual-specificity protein phosphatase 16 (DUSP16)/mitogen-activated protein kinase phosphatase-7 (MKP-7) through the acetylation on Lys55, thus inactivating JNK by dephosphorylation. Based on the recently reported crystal structure of Mtb Eis, a docking model for the binding of Mtb Eis to DUSP16/MKP-7 was generated. In the docking model, the substrate helix containing Lys55 of DUSP16/MKP-7 fits nicely into the active-site cleft of Mtb Eis; the twisted β-sheet of Eis domain II embraces the substrate helix from one side. Most importantly, the side-chain of Lys55 is inserted toward acetyl-CoA and the resulting distance is 4.6 Å between the NZ atom of Lys55 and the carbonyl carbon of the acetyl group in acetyl-CoA. The binding of Mtb Eis and DUSP16/MKP-7 is maintained by strong electrostatic interactions. The active-site cleft of Mtb Eis has a negatively charged surface formed by Asp25, Glu138, Asp286, Glu395 and the terminal carboxylic group of Phe396. In contrast, DUSP16/MKP-7 contains five basic residues, Lys52, Lys55, Arg56, Arg57 and Lys62, which point toward the negatively charged surface of the active-site pocket of Mtb Eis. Thus, the current docking model suggests that the binding of DUSP16/MKP-7 to Mtb Eis should be established by charge complementarity in addition to a very favorable geometric arrangement. The suggested mode of binding requires the dissociation of the hexameric Mtb Eis into dimers or monomers. This study may be useful for future studies aiming to develop inhibitors of Mtb Eis as a new anti-tuberculosis drug candidate.

More than classical Chlamydia psittaci in urban pigeons.

Science.gov (United States)

Sachse, Konrad; Kuehlewind, Simone; Ruettger, Anke; Schubert, Evelyn; Rohde, Gernot

2012-06-15

In the literature, studies of Chlamydia infection in birds have usually been confined to the search for Chlamydia (C., formerly Chlamydophila) psittaci, so that little is known about the presence of other chlamydial agents. In the present study, cloacal swabs and faeces samples of urban pigeons have been examined by real-time PCR, DNA microarray assays and partial ompA sequencing. Whilst C. psittaci was the predominant chlamydial agent in this pigeon population (75.8% of all Chlamydiaceae positives), the combined use of highly specific and sensitive molecular assays facilitated the detection of atypical serovars of C. psittaci, as well as other species of Chlamydia, such as C. abortus. Detection of C. pecorum and C. trachomatis from an avian host is reported here for the first time. Rather unexpectedly, 19.5% of all Chlamydiaceae-positive cases turned out to be infected with non-classified organisms. The considerable prevalence of these novel agents raises the question of their epidemiological importance and possible role as pathogens. Future surveys in domestic and wild birds will have to take the extended variety of chlamydial organisms into account. Copyright © 2012 Elsevier B.V. All rights reserved.

Chlamydia prevalence in the general population: is there a sex difference? a systematic review

OpenAIRE

Dielissen, Patrick W; Teunissen, Doreth AM; Lagro-Janssen, Antoine LM

2013-01-01

Background The focus of Chlamydia trachomatis screening and testing lies more on women than on men. The study aim was to establish by systematic review the prevalence of urogenital Chlamydia trachomatis infection in men and women in the general population. Methods Electronic databases and reference lists were searched from 2000 to 2013 using the key words “Chlamydia trachomatis”, “population-based study” and “disease prevalence”. Reference lists were checked. Studies were included in the anal...

Kinetic studies of Candida parapsilosis phagocytosis by macrophages and detection of intracellular survival mechanisms

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Renata eToth

2014-11-01

Full Text Available Even though the number of Candida infections due to non-albicans species like C. parapsilosis has been increasing, little is known about their pathomechanisms. Certain aspects of C. parapsilosis and host interactions have already been investigated; however we lack information about the innate cellular responses towards this species. The aim of our project was to dissect and compare the phagocytosis of C. parapsilosis to C. albicans and to another Candida species C. glabrata by murine and human macrophages by live cell video microscopy. We broke down the phagocytic process into three stages: macrophage migration, engulfment of fungal cells and host cell killing after the uptake. Our results showed increased macrophage migration towards C. parapsilosis and we observed differences during the engulfment processes when comparing the three species. The engulfment time of C. parapsilosis was comparable to that of C. albicans regardless of the pseudohypha length and spatial orientation relative to phagocytes, while the rate of host cell killing and the overall uptake regarding C. parapsilosis showed similarities mainly with C. glabrata. Furthermore, we observed difference between human and murine phagocytes in the uptake of C. parapsilosis. UV-treatment of fungal cells had varied effects on phagocytosis dependent upon which Candida strain was used. Besides statistical analysis, live cell imaging videos showed that this species similarly to the other two also has the ability to survive in host cells via the following mechanisms: yeast replication, and pseudohypha growth inside of phagocytes, exocytosis of fungal cells and also abortion of host cell mitosis following the uptake. According to our knowledge this is the first study that provides a thorough examination of C. parapsilosis phagocytosis and reports intracellular survival mechanisms associated with this species.

Chlamydia detection during the menstrual cycle: a cross-sectional study of women attending a sexual health service.

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Dana S Forcey

Full Text Available BACKGROUND: We investigated the detection of chlamydia at different stages of the menstrual cycle. METHODS: Electronic medical records for women attending Melbourne Sexual Health Centre between March 2011 and 31(st December 2012, who were tested for chlamydia by nucleic acid amplification of high vaginal, cervical, or urinary samples, and who recorded a date of last normal menstrual period (LNMP between 0-28 days were included in the analysis. Logistic regression was used to calculate adjusted odds ratio (aOR and 95% confidence intervals (CI for the association of chlamydia with menstrual cycle adjusted by demographics and behavioural variables. Chlamydia and beta globin load were determined on those with stored samples. RESULTS: Of the 10,017 consultations that included a test for chlamydia and a valid LNMP, there were 417 in which chlamydia was detected. The proportion of samples with chlamydia was greater in the luteal phase (4.8%, 184/3831 than in the follicular phase (3.4%, 233/6816 both in the crude (OR 1.29 95%CI 1.1-1.6, p = 0.01 and adjusted odds ratio (aOR 1.4 (95%CI 1.1-1.8, p = 0.004. Among women using hormonal contraception, there was no significant association with the luteal phase of the menstrual cycle (aOR 1.3, 95%CI 0.9, 1.8, p = 0.18. Among women not using hormonal contraception, there was a significant association with the luteal phase (aOR 1.6, (95% CI 1.1-2.3, p = 0.007. The chlamydia load was not significantly different in the 329 positive stored samples in weeks 3 and 4 vs weeks 1 and 2 for any site (P>0.12. CONCLUSIONS: The higher detection of chlamydia detection in the luteal phase of the menstrual cycle in only those not taking hormonal contraception suggest that hormonal factors influence chlamydia detection. The absence of a significantly highly chlamydia load in women during the luteal phase raises questions about the mechanism.

Pelvic inflammatory disease risk following negative results from chlamydia nucleic acid amplification tests (NAATs) versus non-NAATs in Denmark

DEFF Research Database (Denmark)

Turner, Katy M E; Benfield, Thomas; Frølund, Maria

2018-01-01

BACKGROUND: Nucleic Acid Amplification Tests (NAATs) are the recommended test type for diagnosing Chlamydia trachomatis (chlamydia). However, less sensitive diagnostic methods-including direct immunofluorescence (IF) and enzyme-linked immunoassay (ELISA)-remain in use in lower resourced settings...... with a chlamydia test, just under half (44.78%, n = 121,857) were tested using NAATs. Overall, 6.38% (n = 17,353) tested positive for chlamydia and 0.64% (n = 1,732) were diagnosed with PID within 12 months. The risk of PID following a positive chlamydia test did not differ by test type (NAAT 0.81% [95% CI 0....... We estimate the risk of pelvic inflammatory disease (PID) following undiagnosed infection in women tested with non-NAATs and estimate the health gain from using accurate diagnostic tests. METHODS AND FINDINGS: We used Denmark's national Chlamydia Study dataset to extract all chlamydia tests performed...

Evaluation of an ompA-based phage-mediated DNA vaccine against Chlamydia abortus in piglets.

Science.gov (United States)

Ou, Changbo; Tian, Deyu; Ling, Yong; Pan, Qing; He, Qing; Eko, Francis O; He, Cheng

2013-08-01

Chlamydia abortus (C. abortus) is an obligate intracellular pathogen that causes abortion in pigs and poses a zoonotic risk in pregnant women. Although attenuated and inactivated vaccines are available, they do not provide complete protection in animals underlining the need to develop new vaccines. In this study, we tested the hypothesis that intramuscular immunization with an ompA-based phage-mediated DNA chlamydial vaccine candidate will induce significant antigen-specific cellular and humoral immune responses. Thus, groups of piglets (five per group) were immunized intramuscularly with the phage-MOMP vaccine (λ-MOMP) or a commercial live-attenuated vaccine (1B vaccine) or a GFP-expressing phage (λ-GFP) or phosphate buffered saline (PBS) (control) and antigen-specific cell-mediated and humoral immune responses were evaluated. By day 63 post-immunization, the λ-MOMP vaccine elicited significantly higher (Pabortus. Copyright © 2013 Elsevier B.V. All rights reserved.

Repeat Chlamydia trachomatis testing among heterosexual STI outpatient clinic visitors in the Netherlands: a longitudinal study.

Science.gov (United States)

Visser, Maartje; van Aar, Fleur; Koedijk, Femke D H; Kampman, Carolina J G; Heijne, Janneke C M

2017-12-20

Chlamydia infections are common in both men and women, are often asymptomatic and can cause serious complications. Repeat testing in high-risk groups is therefore indicated. In the Netherlands, guidelines on repeat chlamydia testing differ between testing facilities, and knowledge on repeat testing behaviour is limited. Here, we analyse the current repeat testing behaviour of heterosexual STI clinic visitors, and aim to identify groups for which repeat testing advice could be advantageous. Longitudinal surveillance data from all Dutch STI outpatient clinics were used, which included all STI clinic consultations carried out among heterosexual men and women between June 2014 and December 2015. Repeat testing was defined as returning to the same STI clinic between 35 days and 12 months after initial consultation. We calculated chlamydia positivity at repeat test stratified by initial test result and time between consultations. Logistic regression analyses were used to identify predictors of repeat testing, and predictors of having a chlamydia positive repeat test. In total, 140,486 consultations in 75,487 women and 46,286 men were available for analyses. Overall, 15.4% of women and 11.1% of men returned to the STI clinic within the study period. Highest chlamydia positivity at repeat test was seen 3-5 months after initial positive test. Among both women and men, repeat testing was associated with non-Western ethnicity, having had more than two sex partners in the past 6 months, reporting STI symptoms, having a history of STI, and having a chlamydia positive initial test. Among repeat testers, chlamydia positive repeat test was most strongly associated with younger age, followed by a chlamydia positive initial test. Repeat testing most often resulted in a positive test result among young heterosexuals (<25) and heterosexuals of any age with a chlamydia infection at the initial consultation. Further efforts are needed to determine optimal repeat testing strategies.

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.

Chlamydia trachomatis inclusion membrane protein CT850 interacts with the dynein light chain DYNLT1 (Tctex1).

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Mital, Jeffrey; Lutter, Erika I; Barger, Alexandra C; Dooley, Cheryl A; Hackstadt, Ted

2015-06-26

Chlamydia trachomatis actively subverts the minus-end directed microtubule motor, dynein, to traffic along microtubule tracks to the Microtubule Organizing Center (MTOC) where it remains within a membrane bound replicative vacuole for the duration of its intracellular development. Unlike most substrates of the dynein motor, disruption of the dynactin cargo-linking complex by over-expression of the p50 dynamitin subunit does not inhibit C. trachomatis transport. A requirement for chlamydial protein synthesis to initiate this process suggests that a chlamydial product supersedes a requirement for p50 dynamitin. A yeast 2-hybrid system was used to screen the chlamydia inclusion membrane protein CT850 against a HeLa cell cDNA library and identified an interaction with the dynein light chain DYNLT1 (Tctex1). This interaction was at least partially dependent upon an (R/K-R/K-X-X-R/K) motif that is characteristic of DYNLT1 binding domains. CT850 expressed ectopically in HeLa cells localized at the MTOC and this localization is similarly dependent upon the predicted DYNLT1 binding domain. Furthermore, DYNLT1 is enriched at focal concentrations of CT850 on the chlamydial inclusion membrane that are known to interact with dynein and microtubules. Depletion of DYNLT1 disrupts the characteristic association of the inclusion membrane with centrosomes. Collectively, the results suggest that CT850 interacts with DYNLT1 to promote appropriate positioning of the inclusion at the MTOC. Published by Elsevier Inc.

Clinical and microscopic signs of cervicitis and urethritis: correlation with Chlamydia trachomatis infection in female STI patients.

Science.gov (United States)

Berntsson, Matilda; Tunbäck, Petra

2013-03-27

Chlamydia trachomatis is among the most prevalent genital infections and is an important cause of tubal factor infertility. The majority of infected females are asymptomatic. Evidence on the reliability of signs of inflammation used to predict chlamydia in female patients is inconsistent. This study examined associations between criteria routinely used in many Scandinavian sexually transmitted infection (STI) clinics and a positive chlamydia test in a high-prevalence population. Clinical and microscopic signs of cervicitis and urethritis were recorded in 99 women attending due to chlamydia infection in a sexual partner. Mucopurulent cervical discharge, easily induced bleeding from the cervix, and more polymorpho-nuclear cells than epithelial cells in vaginal wet smear all correlated significantly with a positive Chlamydia trachomatis test (odds ratios: 3.4, 4.0 and 4.8, respectively). Increased numbers of polymorphonuclear leucocytes (>30 and ≥ 5 respectively) in stained cervical and urethral smears were not significantly correlated with chlamydia infection. Hence, routine collection of cervical and urethral smears in female STI patients is questionable.

Population Genomics of Chlamydia trachomatis: Insights on Drift, Selection, Recombination, and Population Structure

NARCIS (Netherlands)

Joseph, Sandeep J.; Didelot, Xavier; Rothschild, James; de Vries, Henry J. C.; Morré, Servaas A.; Read, Timothy D.; Dean, Deborah

2012-01-01

The large number of sexually transmitted diseases and ocular trachoma cases that are caused globally each year by Chlamydia trachomatis has made this organism a World Health Organization priority for vaccine development. However, there is no gene transfer system for Chlamydia to help identify

Chlamydia prevalence trends among women and men entering the National Job Training Program from 1990 through 2012.

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Learner, Emily R; Torrone, Elizabeth A; Fine, Jason P; Pence, Brian W; Powers, Kimberly A; Miller, William C

2018-01-26

Evaluating chlamydia prevalence trends from sentinel surveillance is important for understanding population disease burden over time. However, prevalence trend estimates from surveillance data may be misleading if they do not account for changes in risk profiles of individuals who are screened (case mix) and changing performance of the screening tests used. We analyzed chlamydia screening data from a sentinel surveillance population of 389,555 young women (1990-2012) and 303,699 young men (2003-2012) entering the US National Job Training Program. This period follows the introduction of national chlamydia screening programs designed to prevent transmission and reduce population disease burden. After ruling out bias due to case mix, we used an expectation-maximization based maximum likelihood approach to account for measurement error from changing screening tests, and generated minimally-biased long-term chlamydia prevalence trend estimates among youth and young adults in this sentinel surveillance population. Adjusted chlamydia prevalence among women was high throughout the study period, but fell from 20% in 1990 to 12% in 2003, and remained between 12% and 14% through 2012. Adjusted prevalence among men was steady throughout the study period at approximately 7%. For both women and men, adjusted prevalence was highest among Black and American Indian youth and young adults, and in the Southern and Midwestern regions of the US throughout the study period. Our minimally-biased trend estimates provide support for an initial decrease in chlamydia prevalence among women soon after the introduction of national chlamydia screening programs. Constant chlamydia prevalence in more recent years suggests that screening may not be sufficient to further reduce chlamydia prevalence among high-risk youth and young adults.

Prevalence of Chlamydia trachomatis infection among women in a Middle Eastern community

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Ghazal-Aswad Saad

2004-05-01

Full Text Available Abstract Background Common vaginal infections that manifest in women are usually easily diagnosed. However, Chlamydia infection is often asymptomatic, leading to infertility before it is detected. If it occurs in pregnancy, it could lead to significant neonatal morbidity. It may also play a role with other viral infections for e.g. Human Papilloma Virus in the development of cervical cancer. The objective of this study was to determine the prevalence of Chlamydia infection in women undergoing screening for cervical abnormalities as a part of a research project in primary and secondary care institutions in the United Arab Emirates. Methods In this cross sectional study married women attending primary and secondary care participating in a large nationwide cervical abnormalities screening survey were offered Chlamydia testing using a commercially available test kit. This kit uses a rapid immunoassay for the direct detection of Chlamydia trachomatis antigen in endocervical swab specimens. As this study was performed in a traditional Islamic country, unmarried women were excluded from testing, as the management of any positive cases would create legal and social problems. All married women consenting to take part in the study were included irrespective of age. Results Of 1039 women approached over a period of eight months 919 (88.5% agreed to participate. The number of women in the 16 to 19 years was small (0.01% and 30% were aged over 40 years. The prevalence of Chlamydia infection in this study was 2.6% (95% confidence interval 1.2–3.3%, which was marginally higher in women screened in secondary care (p = 0.05. Conclusion This is one of the few reports on the prevalence of Chlamydia infection in women from the Middle East. Due to cultural and social constraints this study excluded a large proportion of women aged less than 19 years of age. Hence no direct comparisons on prevalence could be made with studies from the West, which all included

Prevalence of Chlamydia trachomatis infection among patients ...

African Journals Online (AJOL)

sexually transmitted diseases clinic (STD) in Kano, North Western Nigeria. ... A higher percentage of the patients (95.2%) were not aware of the existence of ... Key words: Chlamydia trachomatis, Prevalence, risk factors, Infertility, STD, Kano.

Chlamydia sequelae cost estimates used in current economic evaluations: does one-size-fit-all?

Science.gov (United States)

Ong, Koh Jun; Soldan, Kate; Jit, Mark; Dunbar, J Kevin; Woodhall, Sarah C

2017-02-01

Current evidence suggests that chlamydia screening programmes can be cost-effective, conditional on assumptions within mathematical models. We explored differences in cost estimates used in published economic evaluations of chlamydia screening from seven countries (four papers each from UK and the Netherlands, two each from Sweden and Australia, and one each from Ireland, Canada and Denmark). From these studies, we extracted management cost estimates for seven major chlamydia sequelae. In order to compare the influence of different sequelae considered in each paper and their corresponding management costs on the total cost per case of untreated chlamydia, we applied reported unit sequelae management costs considered in each paper to a set of untreated infection to sequela progression probabilities. All costs were adjusted to 2013/2014 Great British Pound (GBP) values. Sequelae management costs ranged from £171 to £3635 (pelvic inflammatory disease); £953 to £3615 (ectopic pregnancy); £546 to £6752 (tubal factor infertility); £159 to £3341 (chronic pelvic pain); £22 to £1008 (epididymitis); £11 to £1459 (neonatal conjunctivitis) and £433 to £3992 (neonatal pneumonia). Total cost of sequelae per case of untreated chlamydia ranged from £37 to £412. There was substantial variation in cost per case of chlamydia sequelae used in published chlamydia screening economic evaluations, which likely arose from different assumptions about disease management pathways and the country perspectives taken. In light of this, when interpreting these studies, the reader should be satisfied that the cost estimates used sufficiently reflect the perspective taken and current disease management for their respective context. 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/.

Young women's decisions to accept chlamydia screening: influences of stigma and doctor-patient interactions

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O'Connell Emer

2010-07-01

Full Text Available Abstract Background An understanding of the factors that encourage young women to accept, and discourage them from accepting, STI (sexually transmitted infection testing is needed to underpin opportunistic screening programs for the STI Chlamydia trachomatis (opportunistic screening involves healthcare professionals offering chlamydia tests to people while they are attending health services for reasons that are usually unrelated to their sexual health. We conducted a qualitative study to identify and explore: how young women would feel about being offered opportunistic tests for chlamydia?; how young women would like to be offered screening, and who they wanted to be offered screening by?; and what factors would influence young women's partner notification preferences for chlamydia (who they would notify in the event of a positive diagnosis of chlamydia, how they would want to do this. Methods Semi-structured interviews with 35 young women between eighteen and twenty nine years of age. The study was conducted in the Dublin and Galway regions of the Republic of Ireland. Young adults were recruited from General Practice (GP practices, Third Level College health services, Family Planning clinics and specialist STI treatment services. Results Respondents were worried that their identities would become stigmatised if they accepted screening. Younger respondents and those from lower socio-economic backgrounds had the greatest stigma-related concerns. Most respondents indicated that they would accept screening if it was offered to them, however; accepting screening was seen as a correct, responsible action to engage in. Respondents wanted to be offered screening by younger female healthcare professionals. Respondents were willing to inform their current partners about positive chlamydia diagnoses, but were more ambivalent about informing their previous partners. Conclusions If an effort is not put into reducing young women's stigma-related concerns the

Prevalence of Chlamydia trachomatis infection among patients ...

African Journals Online (AJOL)

Prevalence of Chlamydia trachomatis infection among patients attending infertility and sexually transmitted diseases clinic (STD) in Kano, North Western Nigeria. ... A higher percentage of the patients (95.2%) were not aware of the existence of ...

Chlamydia positivity in New Orleans public high schools, 1996-2005: implications for clinical and public health practices.

Science.gov (United States)

Nsuami, M Jacques; Nsa, Musheni; Brennan, Christine; Cammarata, Catherine L; Martin, David H; Taylor, Stephanie N

2013-01-01

To describe the trends in chlamydia positivity among New Orleans high school students tested in a schoolwide screening between 1996 and 2005, and to determine factors associated with chlamydia positivity among students during the 10-year period. Between school years 1995-1996 and 2004-2005, students in New Orleans public high schools were tested for chlamydia using nucleic acid amplification tests (NAAT) in urine specimens (LCx assay until 1999-2000; BD assay from 2000-2001 to 2004-2005). For each year, we calculated chlamydia positivity by dividing the number of students testing positive by the total number of students tested. Data were analyzed separately by gender. Logistic regressions were performed to determine independent predictors of chlamydia positivity during the 10-year period. Between 1996 and 2005, the average chlamydia positivity was 7.0% (95% confidence interval 6.6-7.4) in boys and 13.1% (95% confidence interval 12.6-13.7) in girls (P New Orleans school-age adolescent population. Any benefit of screening on individuals tested was likely to be mitigated by participants' uninterrupted social interactions with the dynamic forces that sustain the sexual transmission of chlamydia in the population. Copyright © 2013 Academic Pediatric Association. Published by Elsevier Inc. All rights reserved.

Prevalência de Chlamydia Pneumoniae e Mycoplasma Pneumoniae em diferentes formas da doença coronariana Prevalencia de Chlamydia Pneumoniae y Mycoplasma Pneumoniae en diferentes formas de la enfermedad coronaria Prevalence of Chlamydia Pneumoniae and Mycoplasma Pneumoniae in different forms of coronary disease

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Irineu Luiz Maia

2009-06-01

Full Text Available FUNDAMENTO: Vários agentes infecciosos foram investigados desde que se demonstrou a associação entre infecção e aterosclerose, porém os resultados desses estudos são conflitantes. OBJETIVO: Testar a associação entre títulos séricos de anticorpos anti-Chlamydia e anti-Mycoplasma em diferentes formas de síndromes coronarianas agudas (SCA. MÉTODOS: Cento e vinte e seis pacientes foram divididos em quatro grupos: SCA com elevação do segmento ST (32 pacientes, SCA sem elevação do segmento ST (30 pacientes, doença arterial coronariana crônica (30 pacientes e doadores de sangue sem doença coronariana conhecida (34 pacientes - grupo-controle. Nos primeiros dois grupos, amostras de soro foram coletadas na admissão (primeiras 24 horas de hospitalização e após 6 meses de seguimento. Nos outros dois grupos, colheu-se apenas uma amostra basal. Em todas as amostras, anticorpos IgG anti-Chlamydia e anti-Mycoplasma foram dosados por imunofluorescência indireta. RESULTADOS: Diferenças significativas foram observadas entre a medida basal e após 6 meses de seguimento nos pacientes com infarto do miocárdio com elevação do segmento ST, tanto para Chlamydia (650±115,7 vs. 307±47,5, p = 0,0001 quanto para Mycoplasma (36,5±5,0 vs. 21,5±3,5, p = 0,0004. Os grupos com SCA tiveram níveis séricos de anticorpos anti-Chlamydia e anti-Mycoplasma mais altos na dosagem basal, em relação aos pacientes com doença arterial coronariana crônica e grupo-controle, mas as diferenças obtidas não tiveram significância estatística. CONCLUSÃO: O presente estudo mostrou associação entre os títulos de anticorpos anti-Chlamydia e anti-Mycoplasma na fase aguda dos pacientes com angina instável ou infarto do miocárdio.FUNDAMENTO: Se han investigado diversos agentes infecciosos desde que se evidenció la asociación entre infección y aterosclerosis, sin embargo esos estudios ofrecen resultados conflictivos. OBJETIVO: Probar la asociación entre

Detection of Chlamydia Trachomatis Infection in Female Partners of Infertile Couples

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Seyed Mehdi Kalantar

2007-01-01

Full Text Available Background: The prevalence of infertility is about 10-15% among the couples overally. Several factors can affect fertility ability of men and women. Chlamydia is a non-motile gram negative obligatory interacellular pathogenic organism. It can cause infections in females as cervicitis, urethritis, endometritis, pelvic inflammatory disease also prostatitis and epidydidimitis in male as well. The aim of this survey is to mention the frequency of infection with Chlamydia in infertile female who were treated in Yazd Research & Clinical Center for Infertility.Materials and Methods: A questionnaire containing some demographic information and clinical features related to the infection was completed for each infertile woman. Specimen of vaginal discharge was collected by well trained nurses using sterile cotton swap from 91 women. Elisa test was done on blood serum. DNA extraction for Chlamydia was carried out using low salt method and PCR was done using MOMP and plasmid primers. DNA sequencing was performed on two PCR products using Chromas LITE ver.2.01 and analyzed by BLAST.Results: Of 91 blood samples collected in this survey, none of them was positive by ELISA. Also there was no positive PCR result. Four PCR products showed a questionable band which was not in the range of Chlamydia. The products underwent DNA sequencing and there were not any finding related to any other micro-organism.Conclusion: However, it is well known that Chlamydia as an infection plays a role in infertility. Nevertheless, there was not evidence of this organism in these infertile patients. It is necessary to design such a survey in larger populations of infertile patients especially on infertile women with tubal infertility and their husbands as well.

Chlamydia trachomatis in cervico vaginal smears of irradiated uteri: cytologic and immune cytochemical aspects

International Nuclear Information System (INIS)

Santos, D.R.; Marziona, F.; Oyafuso, M.; Carvalho, M.I. de

1989-01-01

Cervico vaginal smears of women with uterine carcinoma treated with radiotherapy are analyzed in the present work. A series of such smears showed morphological changes suggestive of Chlamydia infection with the Papanicolaou stain. Confirmation of the presence of such agent was done using an avidin-biotin peroxidase technique. A higher prevalence of Chlamydia in the group of patients with carcinoma of the uterus treated with irradiation than in the population without ionizing treatment was verified. The presence of cells with radiotherapic changes infected by Chlamydia is a new finding in cytology. (author)

Intracellular pH homeostasis in Leishmania donovani amastigotes and promastigotes

International Nuclear Information System (INIS)

Glaser, T.A.; Baatz, J.E.; Kreishman, G.P.; Mukkada, A.J.

1988-01-01

Intracellular pH and pH gradients of Leishmania donovani amastigotes and promastigotes were determined over a broad range of extracellular pH values. Intracellular pH was determined by 31 P NMR and by equilibrium distribution studies with 5,5-dimethyloxazolidine-2,4-dione or methylamine. Promastigotes maintain intracellular pH values close to neutral between extracellular pH values of 5.0 and 7.4. Amastigote intracellular pH is maintained close to neutral at external pH values as low as 4.0. Both life stages maintain a positive pH gradient to an extracellular pH of 7.4, which is important for active transport of substrates. Treatment with ionophores, such as nigericin and carbonyl cyanide m-chlorophenylhydrazone and the ATPase inhibitor dicyclohexylcarbodiimide, reduced pH gradients in both stages. Maintenance of intracellular pH in the physiologic range is especially relevant for the survival of the amastigote in its acidic in vivo environment

Identification of Chlamydiae and Mycoplasma species in ruminants with ocular infections.

Science.gov (United States)

Gupta, S; Chahota, R; Bhardwaj, B; Malik, P; Verma, S; Sharma, M

2015-02-01

Infectious keratoconjunctivitis (IKC) is a highly contagious ocular inflammatory condition, which is often reported in domestic small and large ruminants. Multiple infectious aetiologies are reported to be involved, but information about the role of certain fastidious bacterial pathogens such as chlamydiae and mycoplasmas is limited in India. Hence, this study was performed to determine the role of these pathogens and their identification by molecular approach. A total of 53 samples from 31 ovine, 14 caprine and eight bovine having clinical symptoms were collected and tested using species-specific PCR tests for chlamydiae and mycoplasmas followed by nucleotide sequence analysis. The results showed 77.41, 14.29 and 25% samples were chlamydiae positive in ovine, caprine and bovine, respectively, whereas 41.93, 14.29 and 37.5% prevalence of mycoplasma infection was detected in ovine, caprine and bovines, respectively. Chlamydophila abortus, Chlamydophila psittaci, Mycoplasma arginini and Mycoplasma hyorhinis were detected from tested samples. To the best of our knowledge, this is the first time these species are identified in IKC cases from India. Coinfection of both chlamydial and mycoplasmal species was detected in eight IKC cases of ovine which suggest synergistic roles played by both chlamydiae and mycoplasma in IKC samples. © 2014 The Society for Applied Microbiology.

IL-4-secreting eosinophils promote endometrial stromal cell proliferation and prevent Chlamydia-induced upper genital tract damage.

Science.gov (United States)

Vicetti Miguel, Rodolfo D; Quispe Calla, Nirk E; Dixon, Darlene; Foster, Robert A; Gambotto, Andrea; Pavelko, Stephen D; Hall-Stoodley, Luanne; Cherpes, Thomas L

2017-08-15

Genital Chlamydia trachomatis infections in women typically are asymptomatic and do not cause permanent upper genital tract (UGT) damage. Consistent with this presentation, type 2 innate and T H 2 adaptive immune responses associated with dampened inflammation and tissue repair are elicited in the UGT of Chlamydia -infected women. Primary C. trachomatis infection of mice also causes no genital pathology, but unlike women, does not generate Chlamydia -specific T H 2 immunity. Herein, we explored the significance of type 2 innate immunity for restricting UGT tissue damage in Chlamydia -infected mice, and in initial studies intravaginally infected wild-type, IL-10 -/- , IL-4 -/- , and IL-4Rα -/- mice with low-dose C. trachomatis inoculums. Whereas Chlamydia was comparably cleared in all groups, IL-4 -/- and IL-4Rα -/- mice displayed endometrial damage not seen in wild-type or IL-10 -/- mice. Congruent with the aberrant tissue repair in mice with deficient IL-4 signaling, we found that IL-4Rα and STAT6 signaling mediated IL-4-induced endometrial stromal cell (ESC) proliferation ex vivo, and that genital administration of an IL-4-expressing adenoviral vector greatly increased in vivo ESC proliferation. Studies with IL-4-IRES-eGFP (4get) reporter mice showed eosinophils were the main IL-4-producing endometrial leukocyte (constitutively and during Chlamydia infection), whereas studies with eosinophil-deficient mice identified this innate immune cell as essential for endometrial repair during Chlamydia infection. Together, our studies reveal IL-4-producing eosinophils stimulate ESC proliferation and prevent Chlamydia -induced endometrial damage. Based on these results, it seems possible that the robust type 2 immunity elicited by Chlamydia infection of human genital tissue may analogously promote repair processes that reduce phenotypic disease expression.

Chlamydia Trachomatis IgG Antibodies Seroprevalence Among ...

African Journals Online (AJOL)

2014-12-31

% for males and females respectively), while in the same state, Anaghalu (2006) among a seroprevalence rate of 23.8% for males and 28.0% for females among infertile couples. Chlamydia is known as the “silent epidemic” ...

Modelling the impact of chlamydia screening on the transmission of HIV among men who have sex with men

NARCIS (Netherlands)

M. Xiridou (Maria); H.J. Vriend (Henrike); A.K. Lugnér (Anna); J. Wallinga (Jacco); J.S.A. Fennema (Johan); J.M. Prins (Jan); S.E. Geerlings (Suzanne); B.J.A. Rijnders (Bart); M. Prins (Mariia); H.J.C. de Vries (Henry); M.J. Postma (Maarten); M.G. van Veen (Maaike); M. Schim van der Loeff (Maarten); M.A.B. van der Sande (Marianne)

2013-01-01

textabstractBackground: Recent studies have found high prevalences of asymptomatic rectal chlamydia among HIV-infected men who have sex with men (MSM). Chlamydia could increase the infectivity of HIV and the susceptibility to HIV infection. We investigate the role of chlamydia in the spread of HIV

Topical tenofovir protects against vaginal simian HIV infection in macaques coinfected with Chlamydia trachomatis and Trichomonas vaginalis.

Science.gov (United States)

Makarova, Natalia; Henning, Tara; Taylor, Andrew; Dinh, Chuong; Lipscomb, Jonathan; Aubert, Rachael; Hanson, Debra; Phillips, Christi; Papp, John; Mitchell, James; McNicholl, Janet; Garcia-Lerma, Gerardo J; Heneine, Walid; Kersh, Ellen; Dobard, Charles

2017-03-27

Chlamydia trachomatis and Trichomonas vaginalis, two prevalent sexually transmitted infections, are known to increase HIV risk in women and could potentially diminish preexposure prophylaxis efficacy, particularly for topical interventions that rely on local protection. We investigated in macaques whether coinfection with Chlamydia trachomatis/Trichomonas vaginalis reduces protection by vaginal tenofovir (TFV) gel. Vaginal TFV gel dosing previously shown to provide 100 or 74% protection when applied either 30 min or 3 days before simian HIV(SHIV) challenge was assessed in pigtailed macaques coinfected with Chlamydia trachomatis/Trichomonas vaginalis and challenged twice weekly with SHIV162p3 for up to 10 weeks (two menstrual cycles). Three groups of six macaques received either placebo or 1% TFV gel 30 min or 3 days before each SHIV challenge. We additionally assessed TFV and TFV diphosphate concentrations in plasma and vaginal tissues in Chlamydia trachomatis/Trichomonas vaginalis coinfected (n = 4) and uninfected (n = 4) macaques. Chlamydia trachomatis/Trichomonas vaginalis coinfections were maintained during the SHIV challenge period. All macaques that received placebo gel were SHIV infected after a median of seven challenges (one menstrual cycle). In contrast, no infections were observed in macaques treated with TFV gel 30 min before SHIV challenge (P vaginal lymphocytes were significantly higher in Chlamydia trachomatis/Trichomonas vaginalis coinfected compared with Chlamydia trachomatis/Trichomonas vaginalis uninfected macaques. Our findings in this model suggest that Chlamydia trachomatis/Trichomonas vaginalis coinfection may have little or no impact on the efficacy of highly effective topical TFV modalities and highlight a significant modulation of TFV pharmacokinetics.

Genital Chlamydia trachomatis: An update

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Meenakshi Malhotra

2013-01-01

Full Text Available Chlamydia trachomatis is the most common cause of curable bacterial sexually transmitted infection (STI worldwide. It manifests primarily as urethritis in males and endocervicitis in females. Untreated chlamydial infection in man can cause epididymitis and proctitis. Though most women with Chlamydia infection are asymptomatic or have minimal symptoms, some develop salpingitis, endometritis, pelvic inflammatory disease (PID, ectopic pregnancy and tubal factor infertility. It is associated with an increased risk for the transmission or acquisition of HIV and is also attributed to be a risk factor for the development of cervical carcinoma. Early diagnosis and treatment of infected individuals is required to prevent the spread of the disease and severe sequelae. Traditionally, tissue culture was considered the gold standard for the diagnosis. However, with the availability of newer diagnostic techniques particularly molecular methods which are not only highly sensitive and specific but are cost-effective also, the diagnosis has became fast and easy. The purpose of this review is to study the various aspects of genital C. trachomatis infection. Also the advances related to the clinical picture, various diagnostic modalities, prevention, treatment, drug resistance and control measures will be dealt with.

Isolation of Chlamydia abortus from a laboratory worker diagnosed with atypical pneumonia.

Science.gov (United States)

Ortega, Nieves; Caro, M Rosa; Gallego, M Carmen; Murcia-Belmonte, Antonio; Álvarez, Daniel; Del Río, Laura; Cuello, Francisco; Buendía, Antonio J; Salinas, Jesús

2015-01-01

Identifying the aetiological agent of atypical pneumonia in human can sometimes be a tedious process, especially in cases where Mycoplasma pneumoniae, Legionella species and Chlamydia pneumoniae are ruled out. In such cases, a correct anamnesis of the patient is basic to clarify which pathogens might have produced the infection. For this reason, health professionals including veterinarians and laboratory personnel working with zoonotic pathogens should keep their doctors informed. A human case of atypical pneumonia linked to Chlamydia abortus is reported. A 47-year-old male, a veterinarian researcher into chlamydiae, developed respiratory symptoms, breathing problems and high fever. Serological analyses ruled out the involvement of several respiratory pathogens, such as M. pneumoniae, Legionella pneumophila, Rickettsia conorii and C. pneumoniae, and Chlamydia abortus was identified as the possible aetiological agent of the infection. The isolation of C. abortus from the patient's sputum and subsequent molecular analysis confirmed the presence of this microorganism. As far as we know, although C. abortus has not been previously described as capable of causing pneumonia in humans, this is the first reported case of atypical pneumonia in which C. abortus is thought to have played an aetiological role.

Genital Chlamydia trachomatis infektion hos abortsøgende. Undersøgelses- og behandlingsstrategi for at mindske infektionssequelae

DEFF Research Database (Denmark)

Sørensen, Jette Led; Thranov, I R; Hoff, G E

1992-01-01

Among women applying for termination of pregnancy, 5-17% are infected with Chlamydia trachomatis. The prevalence is higher among women under 20 years of age (12-30%), in nulliparae and when Neisseria gonorrhoeae are found simultaneously. If women applying for termination of pregnancy with Chlamydia...... infection are not treated, 10-60% will develop pelvic infection after abortion. Salpingitis caused by Chlamydia runs a milder clinical course than salpingitis caused by gonococci or other etiology but salpingitis due to Chlamydia is regarded as one of the most important causes of tubal infertility...... and extrauterine pregnancy. The symptoms may be discharge and dysuria or objective findings such as cervicitis and pathological findings in wet smears of the cervical secretion. The majority of women applying for termination of pregnancy with Chlamydia infection have no symptoms. Only few investigations have...

NNDSS - Table II. Chlamydia trachomatis infection to Coccidioidomycosis

Data.gov (United States)

U.S. Department of Health & Human Services — NNDSS - Table II. Chlamydia trachomatis infection to Coccidioidomycosis - 2018. In this Table, provisional cases of selected notifiable diseases (≥1,000 cases...

Barriers and Facilitators of Partner Treatment of Chlamydia: A Qualitative Investigation with Prescribers and Community Pharmacists

Directory of Open Access Journals (Sweden)

Helen Wood

2018-02-01

Full Text Available Chlamydia trachomatis is the most frequently-notified sexually transmitted infection in Australia. Effective and timely partner treatment of chlamydia is essential to reduce overall prevalence and the burden of infection. Currently in most of Australia, the only avenue for partner treatment of chlamydia (“standard partner therapy” is a tedious, and often inconvenient, process. The barriers and facilitators of standard partner therapy, and newer models of accelerated partner therapy (APT, need to be identified in the Australian setting. Additionally, the potential role of community pharmacists need to be explored. Semi-structured interview guides for two key stakeholder groups (prescribers and pharmacists were developed and piloted. Eleven prescribers (general practitioners, sexual health clinicians and nurse practitioners and twelve pharmacists practicing in the Perth metropolitan region were interviewed. Key reported barriers to standard partner therapy were lack of or delayed chlamydia testing. Key facilitators included ability to test and educate sexual partner. Key barriers for APT included prescribers’ legal responsibility and potential for medication-related adverse effects. Healthcare provider consultation and chlamydia testing were seen as potential facilitators of APT. Pharmacists were receptive to the idea of expanding their role in chlamydia treatment, however, barriers to privacy must be overcome in order to be acceptable to prescribers and pharmacists.

Mass media as a population-level intervention tool for Chlamydia trachomatis screening: report of a pilot study.

Science.gov (United States)

Oh, M Kim; Grimley, Diane M; Merchant, Jeanne S; Brown, Pernell R; Cecil, Heather; Hook, Edward W

2002-07-01

To determine the feasibility and affect of mass media use in a population-level intervention for chlamydia screening promotion. A population-level chlamydia intervention protocol was field tested. The intervention, targeting 15-25-year-old individuals, was designed to: (a) increase awareness of personal risk for chlamydial infection; (b) facilitate dissemination of chlamydia knowledge by use of a telephone hot line; and (c) promote care-seeking behavior (report for a chlamydia screening program). The intervention activities included: (a) mail outreach, (b) a television and radio campaign, (c) a prerecorded Check-It-Out chlamydia hot line, (d) a staffed chlamydia Options information line, and (e) a free confidential urine ligase chain reaction (LCR) test for chlamydia. Mass mailings were scheduled at intervals, starting two-weeks before the beginning of the television advertisement. The 30-second television advertisement was aired on local television stations 130 times in a 6-week period. The outcome measures were quantity and characteristics of incoming calls to the automated hot line and staffed chlamydia information phone line in response to the chlamydia campaign, and response to the urine screening program. Descriptive and bivariate analyses were used to evaluate the outcomes. The hot line was called 642 times during the monitoring period (November 1, 1999 to March 8, 2000), the majority (92%) during the 6 weeks of television advertisement, with an average of 99 calls per week, compared with an average of 9 calls per week after the commercial ended. Each bulk mailing was accompanied by a boost in the incoming hot line calls. The research staff triaged 133 calls to the "Options" phone line, 81% in the 6 weeks of the TV ad. The mean age of the 133 callers was 23.9 +/- 7.7 years (range 14-49 years). A majority called for screening information; 67% of callers were females and 84% of female callers were under age 26 years. Five percent of callers identified

Two novel functions of hyaluronidase from Streptococcus agalactiae are enhanced intracellular survival and inhibition of proinflammatory cytokine expression.

Science.gov (United States)

Wang, Zhaofei; Guo, Changming; Xu, Yannan; Liu, Guangjin; Lu, Chengping; Liu, Yongjie

2014-06-01

Streptococcus agalactiae is the causative agent of septicemia and meningitis in fish. Previous studies have shown that hyaluronidase (Hyl) is an important virulence factor in many Gram-positive bacteria. To investigate the role of S. agalactiae Hyl during interaction with macrophages, we inactivated the gene encoding extracellular hyaluronidase, hylB, in a clinical Hyl(+) isolate. The isogenic hylb mutant (Δhylb) displayed reduced survival in macrophages compared to the wild type and stimulated a significantly higher release of proinflammatory cytokines, such as interleukin-1β (IL-1β), IL-6, and tumor necrosis factor alpha (TNF-α), than the wild type in macrophages as well as in mice. Furthermore, only Hyl(+) strains could grow utilizing hyaluronic acid (HA) as the sole carbon source, suggesting that Hyl permits the organism to utilize host HA as an energy source. Fifty percent lethal dose (LD50) determinations in zebrafish demonstrated that the hylb mutant was highly attenuated relative to the wild-type strain. Experimental infection of BALB/c mice revealed that bacterial loads in the blood, spleen, and brain at 16 h postinfection were significantly reduced in the ΔhylB mutant compared to those in wild-type-infected mice. In conclusion, hyaluronidase has a strong influence on the intracellular survival of S. agalactiae and proinflammatory cytokine expression, suggesting that it plays a key role in S. agalactiae pathogenicity.

Using Multiple Outcomes of Sexual Behavior to Provide Insights Into Chlamydia Transmission and the Effectiveness of Prevention Interventions in Adolescents.

Science.gov (United States)

Enns, Eva Andrea; Kao, Szu-Yu; Kozhimannil, Katy Backes; Kahn, Judith; Farris, Jill; Kulasingam, Shalini L

2017-10-01

Mathematical models are important tools for assessing prevention and management strategies for sexually transmitted infections. These models are usually developed for a single infection and require calibration to observed epidemiological trends in the infection of interest. Incorporating other outcomes of sexual behavior into the model, such as pregnancy, may better inform the calibration process. We developed a mathematical model of chlamydia transmission and pregnancy in Minnesota adolescents aged 15 to 19 years. We calibrated the model to statewide rates of reported chlamydia cases alone (chlamydia calibration) and in combination with pregnancy rates (dual calibration). We evaluated the impact of calibrating to different outcomes of sexual behavior on estimated input parameter values, predicted epidemiological outcomes, and predicted impact of chlamydia prevention interventions. The two calibration scenarios produced different estimates of the probability of condom use, the probability of chlamydia transmission per sex act, the proportion of asymptomatic infections, and the screening rate among men. These differences resulted in the dual calibration scenario predicting lower prevalence and incidence of chlamydia compared with calibrating to chlamydia cases alone. When evaluating the impact of a 10% increase in condom use, the dual calibration scenario predicted fewer infections averted over 5 years compared with chlamydia calibration alone [111 (6.8%) vs 158 (8.5%)]. While pregnancy and chlamydia in adolescents are often considered separately, both are outcomes of unprotected sexual activity. Incorporating both as calibration targets in a model of chlamydia transmission resulted in different parameter estimates, potentially impacting the intervention effectiveness predicted by the model.

Prevalência de anticorpos para chlamydia trachomatis em grupos populacionais do Brasil, Inglaterra e Portugal

Directory of Open Access Journals (Sweden)

Marluísa de Oliveira Guimarães Ishak

1988-02-01

Full Text Available A prevalência de anticorpos IgG, grupo-específico para Chlamydia, em populações do Brasil, Inglaterra e Portugal foi determinada através do teste de imunofluorescência indireta, tendo-se como antígeno a cepa SA2 (f. Foram considerados positivos os soros com títulos de IgG >1:32. Dentre as populações brasileiras, a prevalência de anticorpos para Chlamydia foi maior em Serra Norte (76,2%, p < 0,01 do que nas das populações de Belém (53,6% e dos Índios Xicrins (51,3%. Entre os pacientes do Departamento de Medicina Genito-Urinária do University College Hospital (UCH e do quadro do mesmo Hospital, a prevalência de anticorpos anti-Chlamydia foi de 62% e 53,1%, respectivamente. Anticorpos anti-Chlamydia foram detectados em 54% e 66% na Inglaterra e em 56% e 68% em Portugal, nas pacientes do sexo feminino que freqüentavam Clínicas de Pré-Natal e de Infertilidade, respectivamente, Os resultados encontrados mostram uma alta exposição das populações testadas, à Chlamydia, principalmente do grupo de baixo nível sócio-econômico de Serra Norte, Brasil. A evidência de infecção por Chlamydia é da mesma ordem, tanto no Brasil, quanto na Inglaterra e Portugal.

Brain biopsy for diagnosis of chlamydia encephalitis

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I. A. Voznyuk

2017-01-01

Full Text Available This is the case of encephalitis associated with chlamydia infection of central nervous system. The diagnostic protocol of the patient included: a careful observation of somatic and neurological status, laboratory tests of blood and cerebrospinal fluid, neurovisualization. The results of the diagnostic protocol suggest that laboratory tests blood and cerebrospinal fluid possess low sensitivity and specificity. The MRI study has revealed the localization and inflammatory character of the changes in brain tissue; it has also helped to choose the most favorable area for the stereotaxic biopsy. The obtained tissue was evaluated by means of light (immunohistochemistry and electronic microscopy. The active chlamydia infection was estimated. The subsequent antibacterial etiotropic therapy resulted in the regression of the neurologic symptoms and remission.The intravitalpathomorphology study of the brain could be recommended for the management of the severe encephalitis of the unknown origin. 

In vivo activities of Baicalin against Chlamydia trachomatis

African Journals Online (AJOL)

USER

2010-03-15

Rasmussen et al., 1997). The infectivity of the chlamydia was expressed as the number of inclusion forming units. Baicalin (HPLC Content > 98.0%) from Chongqing Green Valley. Bio-tech Co. LTD. (Chongqing, China).

Comparison of Levels of Antibodies against Chlamydia Trachomatis in Infertile Women Due to Tubal Factors and Fertile Women

Directory of Open Access Journals (Sweden)

F Ghalmbor

2009-01-01

Full Text Available Introduction: Chlamydia trachomatis infection is a common pathogen in sexual transmitted disease, but most of female patients with this infection are asymptomatic. Sequealae include pelvic inflammatory disease, infertility and ectopic pregnancy. The aim of the study was to determine the association between Chlamydia trachomatis and tubal factor infertility, if significant. Methods: This prospective, case -control study was done in April 2005-April2006. The study group consisted of 125 patients with tubal factor infertility and the control group included 125 fertile women. The level of antibodies to Chlamydia trachomatis was determined in both groups by ELIZA method. Results: Antibody to Chlamydia trachomatis was present in 29 women in the study group (23.2% and in15 women in the control group ( 12%, respectively, (P< 0.005. The mean level of antibody in both groups was 0.76 and 0.49, respectively (P<0.0005. Conclusion: The study showed that the level of antibody against Chlamydia is significantly more in tubal factor infertile women. We therefore suggest the screening of Chlamydia antibody testing is necessary for tubal factor infertility workup.

Intracellular Complement Activation Sustains T Cell Homeostasis and Mediates Effector Differentiation

Science.gov (United States)

Liszewski, M. Kathryn; Kolev, Martin; Le Friec, Gaelle; Leung, Marilyn; Bertram, Paula G.; Fara, Antonella F.; Subias, Marta; Pickering, Matthew C.; Drouet, Christian; Meri, Seppo; Arstila, T. Petteri; Pekkarinen, Pirkka T.; Ma, Margaret; Cope, Andrew; Reinheckel, Thomas; Rodriguez de Cordoba, Santiago; Afzali, Behdad; Atkinson, John P.; Kemper, Claudia

2013-01-01

Summary Complement is viewed as a critical serum-operative component of innate immunity, with processing of its key component, C3, into activation fragments C3a and C3b confined to the extracellular space. We report here that C3 activation also occurred intracellularly. We found that the T cell-expressed protease cathepsin L (CTSL) processed C3 into biologically active C3a and C3b. Resting T cells contained stores of endosomal and lysosomal C3 and CTSL and substantial amounts of CTSL-generated C3a. While “tonic” intracellular C3a generation was required for homeostatic T cell survival, shuttling of this intracellular C3-activation-system to the cell surface upon T cell stimulation induced autocrine proinflammatory cytokine production. Furthermore, T cells from patients with autoimmune arthritis demonstrated hyperactive intracellular complement activation and interferon-γ production and CTSL inhibition corrected this deregulated phenotype. Importantly, intracellular C3a was observed in all examined cell populations, suggesting that intracellular complement activation might be of broad physiological significance. PMID:24315997

Chlamydia pecorum: fetal and placental lesions in sporadic caprine abortion.

Science.gov (United States)

Giannitti, Federico; Anderson, Mark; Miller, Myrna; Rowe, Joan; Sverlow, Karen; Vasquez, Marce; Cantón, Germán

2016-03-01

Chlamydial abortion in small ruminants is usually associated with Chlamydia abortus infection. Although Chlamydia pecorum has been detected in aborted ruminants and epidemiological data suggests that C. pecorum is abortigenic in these species, published descriptions of lesions in fetuses are lacking. This work describes fetoplacental lesions in a caprine abortion with C. pecorum infection, and further supports the abortigenic role of C. pecorum in ruminants. A 16-month-old Boer goat aborted twin fetuses at ~130 days of gestation. Both fetuses (A and B) and the placenta of fetus A were submitted for postmortem examination and diagnostic workup. At autopsy, the fetuses had moderate anasarca, intermuscular edema in the hindquarters (A), and brachygnathia and palatoschisis (B). In the placenta, the cotyledons were covered by yellow fibrinosuppurative exudate that extended into the adjacent intercotyledonary areas. Histologically, there was severe suppurative and necrotizing placentitis with vasculitis (arteriolitis) and thrombosis, multifocal lymphohistiocytic and neutrophilic hepatitis (A), and fibrinosuppurative enteritis in both fetuses. Chlamydia antigen was detected in the placenta by the direct fluorescent antibody test and in fetal intestines by immunohistochemistry. Nested polymerase chain reaction of DNA extracted from formalin-fixed, paraffin-embedded sections of placenta and intestine amplified 400 bp of the Chlamydia 16S rRNA gene that was sequenced and found to be 99% identical to C. pecorum by BLAST analysis. Other known abortigenic infectious agents were ruled out by specific testing. It is concluded that C. pecorum infection is associated with fetoplacental lesions and sporadic abortion in goats. © 2015 The Author(s).

Orchitis and Epididymitis in Koalas (Phascolarctos cinereus) Infected With Chlamydia pecorum.

Science.gov (United States)

Johnston, S D; Deif, H H; McKinnon, A; Theilemann, P; Griffith, J E; Higgins, D P

2015-11-01

Although Chlamydia causes disease of the urethra and prostate of male koalas, its impact on the testis and epididymis has not been examined. This study describes chronic-active and granulomatous orchitis and epididymitis with interstitial fibrosis associated with infection by Chlamydia pecorum in 2 of 18 adult male koalas being euthanized at a koala hospital, 8 of which also had chlamydial prostatitis. By immunohistochemistry and transmission electron microscopy, chlamydial inclusions were demonstrated within Sertoli cells directly associated with mild inflammation surrounding intact seminiferous and epididymal tubules, marked pyogranulomatous inflammation around disrupted tubules, replacement of tubules by interstitial fibrosis, and aspermia. The presence of C. pecorum but not Chlamydia pneumoniae was detected by quantitative polymerase chain reaction of formalin-fixed tissues of the left and right testes and right epididymis in 1 animal. This is the first report of orchitis and epididymitis in a koala infected with C. pecorum. © The Author(s) 2015.

Transmission Behaviors and Prevalence of Chlamydia and Gonorrhea Among Adult Film Performers.

Science.gov (United States)

Javanbakht, Marjan; Dillavou, M Claire; Rigg, Robert W; Kerndt, Peter R; Gorbach, Pamina M

2017-03-01

Adult film work involves multiple sex partners, unprotected intercourse and frequent oral/rectal contact. Data on sexual networks and sexual behaviors of adult film performers (AFP) are limited. From August 2012 to May 2013, AFPs in Los Angeles, CA, seeking care at 2 clinics that provide sexually transmitted infections (STIs) testing to performers were offered urogenital, pharyngeal, and rectal chlamydia/gonorrhea testing. Participants were 18 years or older and performed in at least 1 adult film scene within the past year. A Web-based survey was used to collect sexual behavior information. A total of 360 AFPs were enrolled; 75% (n = 271) were women, and the median age was 25 years (interquartile range, 22-31 years). Most reported a main partner (73%), 23% reported non-film transactional partners, and only 6% reported always using condoms on-set. Overall, 24% (n = 86) tested positive for chlamydia or gonorrhea; 15% for chlamydia (n = 54) and 11% for gonorrhea (n = 41). Prevalence of chlamydia/gonorrhea varied by time as a performer (median, year 2 vs year 3; P = 0.06), and days of adult film-work in the past 30 days (median, 6 days vs 4 days; P = 0.02). In multivariable analyses, age (adjusted odds ratio, 0.90; 95% confidence interval, 0.85-0.96) and type of scene (adjusted odds ratio for double vaginal = 2.89; 95% confidence interval, 1.29-6.48) were associated with chlamydia/gonorrhea positivity. Adult film performers had a high prevalence of STIs and reported low levels of condom use in the context of most sexual partnerships. Targeted intervention strategies-both in and outside the workplace-are needed to limit the spread of STIs.

Perceptions of Self-Testing for Chlamydia: Understanding and Predicting Self-Test Use.

Science.gov (United States)

Powell, Rachael; Pattison, Helen M; Marriott, John F

2016-05-10

Self-testing technology allows people to test themselves for chlamydia without professional support. This may result in reassurance and wider access to chlamydia testing, but anxiety could occur on receipt of positive results. This study aimed to identify factors important in understanding self-testing for chlamydia outside formal screening contexts, to explore the potential impacts of self-testing on individuals, and to identify theoretical constructs to form a Framework for future research and intervention development. Eighteen university students participated in semi-structured interviews; eleven had self-tested for chlamydia. Data were analysed thematically usingaFrameworkapproach. Perceivedbenefitsofself-testingincludeditsbeingconvenient, anonymousandnotrequiringphysicalexamination. Therewasconcernabouttestaccuracyandsome participants lacked confidence in using vulvo-vaginal swabs. While some participants expressed concern about the absence of professional support, all said they would seek help on receiving a positive result. Factors identified in Protection Motivation Theory and the Theory of Planned Behaviour, such as response efficacy and self-efficacy, were found to be highly salient to participants in thinking about self-testing. These exploratory findings suggest that self-testing independentlyofformalhealthcaresystemsmaynomorenegativelyimpactpeoplethanbeingtested by health care professionals. Participants' perceptions about self-testing behaviour were consistent with psychological theories. Findings suggest that interventions which increase confidence in using self-tests and that provide reassurance of test accuracy may increase self-test intentions.

Beliefs about chlamydia testing amongst young people living in relatively deprived areas.

Science.gov (United States)

Booth, A R; Harris, P R; Goyder, E; Norman, P

2013-06-01

This study uses the theory of planned behaviour (TPB) as a framework to investigate salient beliefs about chlamydia testing, amongst young people living in relatively deprived areas. These beliefs may form targets for intervention to increase testing in this high-risk population. Participants recruited from colleges in deprived areas of a UK city, completed open-ended questions designed to elicit salient beliefs. Responses were content analysed and categorized as describing behavioural, normative or control beliefs. Beliefs were elicited from 128 respondents (51% male; median age = 17). The commonest behavioural belief, which could have a positive or negative impact on screening intentions, was that testing provides information about health status. Partners were referred to most commonly amongst the normative beliefs. Practical aspects and concerns about social implications of testing were common control beliefs. References to several negative emotions emerged throughout. This study indicates that raising awareness of chlamydia as a serious sexual health problem may not be the best way to increase the uptake of testing in a high-risk population. Promoting chlamydia testing as potentially providing reassurance may be an alternative. It may also be important to reduce perceptions of social disapproval as well as negative emotion regarding chlamydia testing.

Chlamydia pecorum Infection in Free-ranging Koalas ( Phascolarctos cinereus ) on French Island, Victoria, Australia.

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Legione, Alistair R; Amery-Gale, Jemima; Lynch, Michael; Haynes, Leesa; Gilkerson, James R; Sansom, Fiona M; Devlin, Joanne M

2016-04-28

We detected Chlamydia pecorum in two koalas ( Phascolarctos cinereus ) from a closed island population in Victoria, Australia, previously free of Chlamydia infection. The ompA and multilocus sequence type were most closely related to published isolates of livestock rather than koala origin, suggesting potential cross-species transmission of C. pecorum .

Determination of Intracellular Vitrification Temperatures for Unicellular Micro Organisms under Conditions Relevant for Cryopreservation.

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Fonseca, Fernanda; Meneghel, Julie; Cenard, Stéphanie; Passot, Stéphanie; Morris, G John

2016-01-01

During cryopreservation ice nucleation and crystal growth may occur within cells or the intracellular compartment may vitrify. Whilst previous literature describes intracellular vitrification in a qualitative manner, here we measure the intracellular vitrification temperature of bacteria and yeasts under conditions relevant to cryopreservation, including the addition of high levels of permeating and nonpermeating additives and the application of rapid rates of cooling. The effects of growth conditions that are known to modify cellular freezing resistance on the intracellular vitrification temperature are also examined. For bacteria a plot of the activity on thawing against intracellular glass transition of the maximally freeze-concentrated matrix (Tg') shows that cells with the lowest value of intracellular Tg' survive the freezing process better than cells with a higher intracellular Tg'. This paper demonstrates the role of the physical state of the intracellular environment in determining the response of microbial cells to preservation and could be a powerful tool to be manipulated to allow the optimization of methods for the preservation of microorganisms.

Serological association of Chlamydia pneumoniae infection with age-related macular degeneration: a systematic review and meta-analysis.

Directory of Open Access Journals (Sweden)

Xueyu Chen

Full Text Available We investigated the serological association of Chlamydia pneumoniae infection with age-related macular degeneration (AMD.A systematic review and meta-analysis was performed. PubMed, Embase, Web of Science and the Association of Research in Vision and Ophthalmology abstracts were searched to identify studies investigating the serological association of Chlamydia pneumoniae infection with age-related macular degeneration. The quality of original studies was assessed using the Newcastle-Ottawa scale. Heterogeneity was explored with meta-regression. The odds ratios (ORs and standardized mean differences (SMD of Chlamydia pneumoniae infection between AMD patients and controls were pooled.In total, 9 studies met the inclusion criteria using the Newcastle-Ottawa scale scores ranging from 4 to 9. There was heterogeneity among studies due to a difference in the study designs and measurement of exposure to Chlamydia pneumoniae infection. The overall OR of Chlamydia pneumoniae infection with AMD was 1.11 (95% confidence interval: 0.78-1.57, P = 0.56. The overall SMD of antibody titer between AMD and control was 0.43 (95% confidence interval: -0.12 to 0.99, P = 0.13.Evidence from the current published literature suggested no statistically significant association between Chlamydia pneumoniae infection and AMD.

Serological association of Chlamydia pneumoniae infection with age-related macular degeneration: a systematic review and meta-analysis.

Science.gov (United States)

Chen, Xueyu; Jhanji, Vishal; Chen, Chupeng; Chen, Haoyu

2014-01-01

We investigated the serological association of Chlamydia pneumoniae infection with age-related macular degeneration (AMD). A systematic review and meta-analysis was performed. PubMed, Embase, Web of Science and the Association of Research in Vision and Ophthalmology abstracts were searched to identify studies investigating the serological association of Chlamydia pneumoniae infection with age-related macular degeneration. The quality of original studies was assessed using the Newcastle-Ottawa scale. Heterogeneity was explored with meta-regression. The odds ratios (ORs) and standardized mean differences (SMD) of Chlamydia pneumoniae infection between AMD patients and controls were pooled. In total, 9 studies met the inclusion criteria using the Newcastle-Ottawa scale scores ranging from 4 to 9. There was heterogeneity among studies due to a difference in the study designs and measurement of exposure to Chlamydia pneumoniae infection. The overall OR of Chlamydia pneumoniae infection with AMD was 1.11 (95% confidence interval: 0.78-1.57, P = 0.56). The overall SMD of antibody titer between AMD and control was 0.43 (95% confidence interval: -0.12 to 0.99, P = 0.13). Evidence from the current published literature suggested no statistically significant association between Chlamydia pneumoniae infection and AMD.

Spontaneous pharyngeal Chlamydia trachomatis RNA clearance. A cross-sectional study followed by a cohort study of untreated STI clinic patients in Amsterdam, The Netherlands

NARCIS (Netherlands)

van Rooijen, Martijn S.; van der Loeff, Maarten F. Schim; Morré, Servaas A.; van Dam, Alje P.; Speksnijder, Arjen G. C. L.; de Vries, Henry J. C.

2015-01-01

Objectives Pharyngeal Chlamydia trachomatis (chlamydia) might contribute to ongoing chlamydia transmission, yet data on spontaneous clearance duration are rare. We examined the prevalence, spontaneous clearance, chlamydial DNA concentration and genotypes of pharyngeal chlamydia among clinic patients

Exploring Anti-Bacterial Compounds against Intracellular Legionella

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Harrison, Christopher F.; Kicka, Sébastien; Trofimov, Valentin; Berschl, Kathrin; Ouertatani-Sakouhi, Hajer; Ackermann, Nikolaus; Hedberg, Christian; Cosson, Pierre; Soldati, Thierry; Hilbi, Hubert

2013-01-01

Legionella pneumophila is a ubiquitous fresh-water bacterium which reproduces within its erstwhile predators, environmental amoeba, by subverting the normal pathway of phagocytosis and degradation. The molecular mechanisms which confer resistance to amoeba are apparently conserved and also allow replication within macrophages. Thus, L. pneumophila can act as an ‘accidental’ human pathogen and cause a severe pneumonia known as Legionnaires’ disease. The intracellular localisation of L. pneumophila protects it from some antibiotics, and this fact must be taken into account to develop new anti-bacterial compounds. In addition, the intracellular lifestyle of L. pneumophila may render the bacteria susceptible to compounds diminishing bacterial virulence and decreasing intracellular survival and replication of this pathogen. The development of a single infection cycle intracellular replication assay using GFP-producing L. pneumophila and Acanthamoeba castellanii amoeba is reported here. This fluorescence-based assay allows for continuous monitoring of intracellular replication rates, revealing the effect of bacterial gene deletions or drug treatment. To examine how perturbations of the host cell affect L. pneumophila replication, several known host-targeting compounds were tested, including modulators of cytoskeletal dynamics, vesicle scission and Ras GTPase localisation. Our results reveal a hitherto unrealized potential antibiotic property of the β-lactone-based Ras depalmitoylation inhibitor palmostatin M, but not the closely related inhibitor palmostatin B. Further characterisation indicated that this compound caused specific growth inhibition of Legionella and Mycobacterium species, suggesting that it may act on a common bacterial target. PMID:24058631

Exploring anti-bacterial compounds against intracellular Legionella.

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Christopher F Harrison

Full Text Available Legionella pneumophila is a ubiquitous fresh-water bacterium which reproduces within its erstwhile predators, environmental amoeba, by subverting the normal pathway of phagocytosis and degradation. The molecular mechanisms which confer resistance to amoeba are apparently conserved and also allow replication within macrophages. Thus, L. pneumophila can act as an 'accidental' human pathogen and cause a severe pneumonia known as Legionnaires' disease. The intracellular localisation of L. pneumophila protects it from some antibiotics, and this fact must be taken into account to develop new anti-bacterial compounds. In addition, the intracellular lifestyle of L. pneumophila may render the bacteria susceptible to compounds diminishing bacterial virulence and decreasing intracellular survival and replication of this pathogen. The development of a single infection cycle intracellular replication assay using GFP-producing L. pneumophila and Acanthamoebacastellanii amoeba is reported here. This fluorescence-based assay allows for continuous monitoring of intracellular replication rates, revealing the effect of bacterial gene deletions or drug treatment. To examine how perturbations of the host cell affect L. pneumophila replication, several known host-targeting compounds were tested, including modulators of cytoskeletal dynamics, vesicle scission and Ras GTPase localisation. Our results reveal a hitherto unrealized potential antibiotic property of the β-lactone-based Ras depalmitoylation inhibitor palmostatin M, but not the closely related inhibitor palmostatin B. Further characterisation indicated that this compound caused specific growth inhibition of Legionella and Mycobacterium species, suggesting that it may act on a common bacterial target.

Monitoring county-level chlamydia incidence in Texas, 2004 – 2005: application of empirical Bayesian smoothing and Exploratory Spatial Data Analysis (ESDA methods

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Owens Chantelle J

2009-02-01

Full Text Available Abstract Background Chlamydia continues to be the most prevalent disease in the United States. Effective spatial monitoring of chlamydia incidence is important for successful implementation of control and prevention programs. The objective of this study is to apply Bayesian smoothing and exploratory spatial data analysis (ESDA methods to monitor Texas county-level chlamydia incidence rates by examining spatiotemporal patterns. We used county-level data on chlamydia incidence (for all ages, gender and races from the National Electronic Telecommunications System for Surveillance (NETSS for 2004 and 2005. Results Bayesian-smoothed chlamydia incidence rates were spatially dependent both in levels and in relative changes. Erath county had significantly (p 300 cases per 100,000 residents than its contiguous neighbors (195 or less in both years. Gaines county experienced the highest relative increase in smoothed rates (173% – 139 to 379. The relative change in smoothed chlamydia rates in Newton county was significantly (p Conclusion Bayesian smoothing and ESDA methods can assist programs in using chlamydia surveillance data to identify outliers, as well as relevant changes in chlamydia incidence in specific geographic units. Secondly, it may also indirectly help in assessing existing differences and changes in chlamydia surveillance systems over time.

The prevalence and identity of Chlamydia-specific IgE in children with asthma and other chronic respiratory symptoms

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Patel Katir K

2012-04-01

Full Text Available Abstract Background Recent studies have confirmed the presence of viable Chlamydia in the bronchoalveolar lavage (BAL fluid of pediatric patients with airway hyperresponsiveness. While specific IgG and IgM responses to C. pneumoniae are well described, the response and potential contribution of Ag-specific IgE are not known. The current study sought to determine if infection with Chlamydia triggers the production of pathogen-specific IgE in children with chronic respiratory diseases which might contribute to inflammation and pathology. Methods We obtained BAL fluid and serum from pediatric respiratory disease patients who were generally unresponsive to corticosteroid treatment as well as sera from age-matched control patients who saw their doctor for wellness checkups. Chlamydia-specific IgE was isolated from BAL and serum samples and their specificity determined by Western blot techniques. The presence of Chlamydia was confirmed by species-specific PCR and BAL culture assays. Results Chlamydial DNA was detected in the BAL fluid of 134/197 (68% patients. Total IgE increased with age until 15 years old and then decreased. Chlamydia-specific IgE was detected in the serum and/or BAL of 107/197 (54% patients suffering from chronic respiratory disease, but in none of the 35 healthy control sera (p p = 0.0001 tested positive for Chlamydia-specific IgE. Asthmatic patients had significantly higher IgE levels compared to non-asthmatics (p = 0.0001. Patients who were positive for Chlamydia DNA or culture had significantly higher levels of serum IgE compared to negative patients (p = 0.0071 and p = 0.0001 respectively. Only 6 chlamydial antigens induced Chlamydia-specific IgE and patients with C. pneumoniae-specific IgE had significantly greater levels of total IgE compared to C. pneumoniae-specific IgE negative ones (p = 0.0001. Conclusions IgE antibodies play a central role in allergic inflammation; therefore production of Chlamydia

Evaluation of patients with dry eye disease for conjunctival Chlamydia trachomatis and Ureaplasma urealyticum.

Science.gov (United States)

Abdelfattah, Maha Mohssen; Khattab, Rania Abdelmonem; Mahran, Magda H; Elborgy, Ebrahim S

2016-01-01

To determine the possibility of the development of dry eye disease (DED) as a result of persistent infection with Chlamydia trachomatis and Ureaplasma urealyticum in the conjunctiva of patients. This study was conducted on 58 patients of age range 20-50y, diagnosed with DED confirmed by Schirmer I test and tear breakup time. The non-dry eye control group included 27 subjects of the same age. Ocular specimens were collected as conjunctival scrapings and swabs divided into three groups: the first used for bacterial culture, the second and third taken to detect Chlamydia trachomatis and Ureaplasma urealyticum by direct fluorescent antibody (DFA) assay and polymerase chain reaction (PCR) method. Chlamydia trachomatis was detected in 65.5% and 76% of DED patients by DFA and PCR methods respectively. Ureaplasma urealyticum was found in 44.8% of DED infected patients using the PCR method. Both organisms were identified in only 37.9% of DED patients found to be infected. Control subjects had a 22% detection rate of Chlamydia trachomatis by DFA assay versus a 7% detection rate by PCR; while Ureaplasma urealyticum was detected in 3.7% of the controls by PCR method. The conjunctival culture revealed that gram positive microorganisms represented 75% of isolates with coagulase negative Staphylococci the most common (50%) followed by Staphylococcus aureus (20%), whereas gram negative microorganisms occurred in 25% of cases, isolating Moraxella spp. as the most frequent organism. Our results tend to point out that Chlamydia trachomatis and Ureaplasma urealyticum were detected in a moderate percentage of patients with DED, and could be a fair possibility for its development. PCR is more reliable in detecting Chlamydia trachomatis than DFA technique. The presence of isolated conjunctival bacterial microflora can be of some potential value.

Global survey of mRNA levels and decay rates of Chlamydia trachomatis trachoma and lymphogranuloma venereum biovars.

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Ferreira, Rita; Borges, Vítor; Borrego, Maria José; Gomes, João Paulo

2017-07-01

Interpreting the intricate bacterial transcriptomics implies understanding the dynamic relationship established between de novo transcription and the degradation of transcripts. Here, we performed a comparative overview of gene expression levels and mRNA decay rates for different-biovar (trachoma and lymphogranuloma venereum) strains of the obligate intracellular bacterium Chlamydia trachomatis . By using RNA-sequencing to measure gene expression levels at mid developmental stage and mRNA decay rates upon rifampicin-based transcription blockage, we observed that: i ) 60-70% of the top-50 expressed genes encode proteins with unknown function and proteins involved in "Translation, ribosomal structure and biogenesis" for all strains; ii ) the expression ranking by genes' functional categories was in general concordant among different-biovar strains; iii ) the median of the half-life time (t 1/2 ) values of transcripts were 15-17 min, indicating that the degree of transcripts' stability seems to correlate with the bacterial intracellular life-style, as these values are considerably higher than the ones observed in other studies for facultative intracellular and free-living bacteria; iv ) transcript decay rates were highly heterogeneous within each C. trachomatis strain and did not correlate with steady-state expression levels; v ) only at very few instances (essentially at gene functional category level) was possible to unveil dissimilarities potentially underlying phenotypic differences between biovars. In summary, the unveiled transcriptomic scenario, marked by a general lack of correlation between transcript production and degradation and a huge inter-transcript heterogeneity in decay rates, likely reflects the challenges underlying the unique biphasic developmental cycle of C. trachomatis and its intricate interactions with the human host, which probably exacerbate the complexity of the bacterial transcription regulation.

Late production of CXCL8 in ruminant oro-nasal turbinate cells in response to Chlamydia abortus infection.

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Doull, L; Wattegedera, S R; Longbottom, D; Mwangi, D; Nath, M; Glass, E J; Entrican, G

2015-11-15

Chlamydia abortus is an obligate intracellular bacterium that is an important cause of ovine abortion worldwide. There are reports of abortions in cattle, but these are very rare compared to the reported incidence in sheep. The bacterium is transmitted oro-nasally and can establish a sub-clinical infection until pregnancy, when it can invade the placenta and induce an inflammatory cascade leading to placentitis and abortion. Early host-pathogen interactions could explain differential pathogenesis and subsequent disease outcome in ruminant species. In this study, we assessed the ability of sheep and cattle oro-nasal turbinate cells to sense and respond to C. abortus infection. The cells expressed toll like receptor (TLR) 2, TLR4, nucleotide oligomerization domain (NOD) 1 and NOD-like receptor pyrin domain containing 3 (NLRP3) mRNA. In response to C. abortus infection, both ovine and bovine turbinate cells produce CXCL8 mRNA and protein late in the bacterial developmental cycle, but do not produce IL-1β or TNF-α. The UV-inactivated bacteria did not elicit a CXCL8 response, suggesting that intracellular multiplication of the bacteria is important for activating the signalling pathways. The production of innate immune cytokines from cattle and sheep turbinate cells in response to C. abortus infection was found to be largely similar. Copyright © 2015 Elsevier B.V. All rights reserved.

Qualitative interviews with healthcare staff in four European countries to inform adaptation of an intervention to increase chlamydia testing.

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McNulty, Cliodna; Ricketts, Ellie J; Fredlund, Hans; Uusküla, Anneli; Town, Katy; Rugman, Claire; Tisler-Sala, Anna; Mani, Alix; Dunais, Brigitte; Folkard, Kate; Allison, Rosalie; Touboul, Pia

2017-09-25

To determine the needs of primary healthcare general practice (GP) staff, stakeholders and trainers to inform the adaptation of a locally successful complex intervention (Chlamydia Intervention Randomised Trial (CIRT)) aimed at increasing chlamydia testing within primary healthcare within South West England to three EU countries (Estonia, France and Sweden) and throughout England. Qualitative interviews. European primary healthcare in England, France, Sweden and Estonia with a range of chlamydia screening provision in 2013. 45 GP staff, 13 trainers and 18 stakeholders. The iterative interview schedule explored participants' personal attitudes, subjective norms and perceived behavioural controls around provision of chlamydia testing, sexual health services and training in general practice. Researchers used a common thematic analysis. Findings were similar across all countries. Most participants agreed that chlamydia testing and sexual health services should be offered in general practice. There was no culture of GP staff routinely offering opportunistic chlamydia testing or sexual health advice, and due to other priorities, participants reported this would be challenging. All participants indicated that the CIRT workshop covering chlamydia testing and sexual health would be useful if practice based, included all practice staff and action planning, and was adequately resourced. Participants suggested minor adaptations to CIRT to suit their country's health services. A common complex intervention can be adapted for use across Europe, despite varied sexual health provision. The intervention (ChlamydiA Testing Training in Europe (CATTE)) should comprise: a staff workshop covering sexual health and chlamydia testing rates and procedures, action planning and patient materials and staff reminders via computer prompts, emails or newsletters, with testing feedback through practice champions. CATTE materials are available at: www.STItraining.eu. © Article author(s) (or their

Prevalence of Chlamydia trachomatis infections in symptomatic ...

African Journals Online (AJOL)

Chlamydia trachomatis is a ubiquitous human pathogen that is responsible for the most prevalent bacterial sexually transmitted disease worldwide. Studies show that polymerase chain reaction (PCR) is more sensitive than cellular culture for detection of C. trachomatis infections. The aim of this study is to compare different ...

Typing of lymphogranuloma venereum Chlamydia trachomatis strains

NARCIS (Netherlands)

Christerson, Linus; de Vries, Henry J. C.; de Barbeyrac, Bertille; Gaydos, Charlotte A.; Henrich, Birgit; Hoffmann, Steen; Schachter, Julius; Thorvaldsen, Johannes; Vall-Mayans, Martí; Klint, Markus; Herrmann, Björn; Morré, Servaas A.

2010-01-01

We analyzed by multilocus sequence typing 77 lymphogranuloma venereum Chlamydia trachomatis strains from men who have sex with men in Europe and the United States. Specimens from an outbreak in 2003 in Europe were monoclonal. In contrast, several strains were in the United States in the 1980s,

Urogenital Chlamydia trachomatis Infections among Ethnic Groups in Paramaribo, Suriname; Determinants and Ethnic Sexual Mixing Patterns

NARCIS (Netherlands)

van der Helm, Jannie J.; Bom, Reinier J. M.; Grünberg, Antoon W.; Bruisten, Sylvia M.; Schim van der Loeff, Maarten F.; Sabajo, Leslie O. A.; de Vries, Henry J. C.

2013-01-01

Little is known about the epidemiology of urogenital Chlamydia trachomatis infection (chlamydia) in Suriname. Suriname is a society composed of many ethnic groups, such as Creoles, Maroons, Hindustani, Javanese, Chinese, Caucasians, and indigenous Amerindians. We estimated determinants for

Intracellular Trafficking Modulation by Ginsenoside Rg3 Inhibits Brucella abortus Uptake and Intracellular Survival within RAW 264.7 Cells.

Science.gov (United States)

Huy, Tran Xuan Ngoc; Reyes, Alisha Wehdnesday Bernardo; Hop, Huynh Tan; Arayan, Lauren Togonon; Min, WonGi; Lee, Hu Jang; Rhee, Man Hee; Chang, Hong Hee; Kim, Suk

2017-03-28

Ginsenoside Rg3, a saponin extracted from ginseng, has various pharmacological and biological activities; however, its effects against Brucella infection are still unclear. Herein, the inhibitory effects of ginsenoside Rg3 against intracellular parasitic Brucella infection were evaluated through bacterial infection, adherence assays, and LAMP-1 colocalization, as well as immunoblotting and FACS for detecting MAPK signaling proteins and F-actin polymerization, respectively. The internalization, intracellular growth, and adherence of Brucella abortus in Rg3-treated RAW 264.7 cells were significantly decreased compared with the Rg3-untreated control. Furthermore, an apparent reduction of F-actin content and intensity of F-actin fluorescence in Rg3-treated cells was observed compared with B. abortus -infected cells without treatment by flow cytometry analysis and confocal microscopy, respectively. In addition, treating cells with Rg3 decreased the phosphorylation of MAPK signaling proteins such as ERK 1/2 and p38 compared with untreated cells. Moreover, the colocalization of B. abortus -containing phagosomes with LAMP-1 was markedly increased in Rg3-treated cells. These findings suggest that ginsenoside Rg3 inhibits B. abortus infection in mammalian cells and can be used as an alternative approach in the treatment of brucellosis.

Chlamydia trachomatis Serology in Women with and without Ovarian Cancer

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Roberta B. Ness

2008-01-01

Full Text Available Pelvic inflammation has been implicated in the genesis of ovarian cancer. We conducted serologic measurements of Chlamydia trachomatis antibodies as a surrogate marker of chlamydial pelvic inflammatory disease. Women with ovarian cancer (n=521 and population-based controls (n=766 were tested. IgG antibodies to serovar D of chlamydia elementary bodies (EBs were detected using an ELISA assay. The odds of having ovarian cancer among women with the highest titers (≥0.40 OD units were 0.6 (95% CI 0.4–0.9. These data do not support our earlier finding of elevated titers for antibodies to C. trachomatis among women with ovarian cancer.

Zoonotic transmission of Chlamydia psittaci in a chicken and turkey hatchery.

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Dickx, Veerle; Vanrompay, Daisy

2011-06-01

Chlamydia psittaci is an obligately intracellular Gram-negative bacterium causing respiratory disease (chlamydiosis) or asymptomatic carriage in birds. C. psittaci is a zoonotic agent causing psittacosis or parrot fever in humans. Vertical and/or horizontal transmission via eggs might have serious repercussions on the C. psittaci infection status of poultry flocks and thus on zoonotic risk for all workers along the poultry supply chain. We therefore studied the presence of C. psittaci in a hatchery. In addition, we examined all (n = 4) employees of the hatchery to evaluate the zoonotic risk. We could not detect C. psittaci on either eggshells or eggshell membranes. However, C. psittaci isolates of different outer-membrane protein A (ompA) genotypes were cultured from the air of both turkey (genotypes A and C) and chicken (genotype D) hatching chambers. Zoonotic transmission occurred in all employees and a mixed infection with up to three different genotypes (A, D and C), also found in air samples, was discovered. Diagnostic monitoring and reporting of C. psittaci infections in poultry workers should be promoted. Additionally, an efficient veterinary vaccine and information campaigns on zoonotic risk and preventive measures against C. psittaci transmission would be beneficial to public health.

Perceptions of Self-Testing for Chlamydia: Understanding and Predicting Self-Test Use

Directory of Open Access Journals (Sweden)

Rachael Powell

2016-05-01

Full Text Available Background: Self-testing technology allows people to test themselves for chlamydia without professional support. This may result in reassurance and wider access to chlamydia testing, but anxiety could occur on receipt of positive results. This study aimed to identify factors important in understanding self-testing for chlamydia outside formal screening contexts, to explore the potential impacts of self-testing on individuals, and to identify theoretical constructs to form a Framework for future research and intervention development. Methods: Eighteen university students participated in semi-structured interviews; eleven had self-tested for chlamydia. Data were analysed thematically usingaFrameworkapproach. Results: Perceivedbenefitsofself-testingincludeditsbeingconvenient, anonymousandnotrequiringphysicalexamination. Therewasconcernabouttestaccuracyandsome participants lacked confidence in using vulvo-vaginal swabs. While some participants expressed concern about the absence of professional support, all said they would seek help on receiving a positive result. Factors identified in Protection Motivation Theory and the Theory of Planned Behaviour, such as response efficacy and self-efficacy, were found to be highly salient to participants in thinking about self-testing. Conclusions: These exploratory findings suggest that self-testing independentlyofformalhealthcaresystemsmaynomorenegativelyimpactpeoplethanbeingtested by health care professionals. Participants’ perceptions about self-testing behaviour were consistent with psychological theories. Findings suggest that interventions which increase confidence in using self-tests and that provide reassurance of test accuracy may increase self-test intentions.

Knowledge of Chlamydia trachomatis among men and women approached to participate in community-based screening, Scotland, UK

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Hart Graham J

2010-12-01

Full Text Available Abstract Background Poor awareness and knowledge of Chlamydia trachomatis could be a barrier to uptake of screening. This study aimed to determine the level of awareness and knowledge of chlamydia among young people who were being approached in a variety of community settings and offered opportunistic screening. Methods Men and women aged 16-24 years were approached in education, health and fitness, and workplace settings and invited to complete a self-administered questionnaire then provide a urine sample for chlamydia testing. Follow-up semi-structured interviews with 24 respondents were carried out after test results were received. Results 363 questionnaires were completed (43.5% from men. Whilst awareness of chlamydia was high, knowledge decreased as questions became increasingly focussed so that around half of respondents were unaware of the asymptomatic nature of chlamydia infections. Men's knowledge of symptoms was consistently lower than women's, with most men failing to identify unusual discharge as a symptom in men (men 58.3%, female 45.8%, p = 0.019; fewer men knew unusual discharge was a symptom among women (men 65.3% female 21.4%, p Conclusions Despite scientific gains in understanding chlamydia infection, public understanding remains limited. Greater efforts are required to translate scientific evidence to the public. An improvement in knowledge may maximise gains from interventions to improve detection.

Knowledge of Chlamydia trachomatis among men and women approached to participate in community-based screening, Scotland, UK.

Science.gov (United States)

Lorimer, Karen; Hart, Graham J

2010-12-30

Poor awareness and knowledge of Chlamydia trachomatis could be a barrier to uptake of screening. This study aimed to determine the level of awareness and knowledge of chlamydia among young people who were being approached in a variety of community settings and offered opportunistic screening. Men and women aged 16-24 years were approached in education, health and fitness, and workplace settings and invited to complete a self-administered questionnaire then provide a urine sample for chlamydia testing. Follow-up semi-structured interviews with 24 respondents were carried out after test results were received. 363 questionnaires were completed (43.5% from men). Whilst awareness of chlamydia was high, knowledge decreased as questions became increasingly focussed so that around half of respondents were unaware of the asymptomatic nature of chlamydia infections. Men's knowledge of symptoms was consistently lower than women's, with most men failing to identify unusual discharge as a symptom in men (men 58.3%, female 45.8%, p = 0.019); fewer men knew unusual discharge was a symptom among women (men 65.3% female 21.4%, p participation in the study. Despite scientific gains in understanding chlamydia infection, public understanding remains limited. Greater efforts are required to translate scientific evidence to the public. An improvement in knowledge may maximise gains from interventions to improve detection.

Influence of the tryptophan-indole-IFNγ axis on human genital Chlamydia trachomatis infection: role of vaginal co-infections.

Science.gov (United States)

Aiyar, Ashok; Quayle, Alison J; Buckner, Lyndsey R; Sherchand, Shardulendra P; Chang, Theresa L; Zea, Arnold H; Martin, David H; Belland, Robert J

2014-01-01

The natural history of genital Chlamydia trachomatis infections can vary widely; infections can spontaneously resolve but can also last from months to years, potentially progressing to cause significant pathology. The host and bacterial factors underlying this wide variation are not completely understood, but emphasize the bacterium's capacity to evade/adapt to the genital immune response, and/or exploit local environmental conditions to survive this immune response. IFNγ is considered to be a primary host protective cytokine against endocervical C. trachomatis infections. IFNγ acts by inducing the host enzyme indoleamine 2,3-dioxgenase, which catabolizes tryptophan, thereby depriving the bacterium of this essential amino acid. In vitro studies have revealed that tryptophan deprivation causes Chlamydia to enter a viable but non-infectious growth pattern that is termed a persistent growth form, characterized by a unique morphology and gene expression pattern. Provision of tryptophan can reactivate the bacterium to the normal developmental cycle. There is a significant difference in the capacity of ocular and genital C. trachomatis serovars to counter tryptophan deprivation. The latter uniquely encode a functional tryptophan synthase to synthesize tryptophan via indole salvage, should indole be available in the infection microenvironment. In vitro studies have confirmed the capacity of indole to mitigate the effects of IFNγ; it has been suggested that a perturbed vaginal microbiome may provide a source of indole in vivo. Consistent with this hypothesis, the microbiome associated with bacterial vaginosis includes species that encode a tryptophanase to produce indole. In this review, we discuss the natural history of genital chlamydial infections, morphological and molecular changes imposed by IFNγ on Chlamydia, and finally, the microenvironmental conditions associated with vaginal co-infections that can ameliorate the effects of IFNγ on C. trachomatis.

Influence of the tryptophan-indole-IFNγ axis on human genital Chlamydia trachomatis infection: role of vaginal co-infections

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Ashok eAiyar

2014-06-01

Full Text Available The natural history of genital Chlamydia trachomatis infections can vary widely; infections can spontaneously resolve but can also last from months to years, potentially progressing to cause significant pathology. The host and bacterial factors underlying this wide variation are not completely understood, but emphasize the bacterium’s capacity to evade/adapt to the genital immune response, and/or exploit local environmental conditions to survive this immune response. IFNγ is considered to be a primary host protective cytokine against endocervical C. trachomatis infections. IFNγ acts by inducing the host enzyme indoleamine 2,3-dioxygenase, which catabolizes tryptophan, thereby depriving the bacterium of this essential amino acid. In vitro studies have revealed that tryptophan deprivation causes Chlamydia to enter a viable but non-infectious growth pattern that is termed a persistent growth form, characterized by a unique morphology and gene expression pattern. Provision of tryptophan can reactivate the bacterium to the normal developmental cycle. There is a significant difference in the capacity of ocular and genital C. trachomatis serovars to counter tryptophan deprivation. The latter uniquely encode a functional tryptophan synthase to synthesize tryptophan via indole salvage, should indole be available in the infection microenvironment. In vitro studies have confirmed the capacity of indole to mitigate the effects of IFNγ; it has been suggested that a perturbed vaginal microbiome may provide a source of indole in vivo. Consistent with this hypothesis, the microbiome associated with bacterial vaginosis includes species that encode a tryptophanase to produce indole. In this review, we discuss the natural history of genital chlamydial infections, morphological and molecular changes imposed by IFNγ on Chlamydia, and finally, the microenvironmental conditions associated with vaginal co-infections that can ameliorate the effects of IFNγ on C

Microbiological study of neonatal conjunctivitis with special reference to chlamydia trachomatis.

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Mohile Mukula

2002-01-01

Full Text Available PURPOSE: To study the microbial agents, chiefly Chlamydia trachomatis and other bacteria, in neonatal conjunctivitis. METHODS: Conjunctival specimens from 70 newborns with conjunctivitis were subjected to bacterial culture and sensitivity testing, monoclonal antibody based C. trachomatis antigen detection test and species-specific Chlamydia antibody detection in the sera of babies and their mothers, by micro-immunofluorescence assay. RESULTS: Bacteria were isolated from 35 (50% babies; the majority (20, 57.14% were Staphylococcus epidermidis. C. trachomatis antigen was detected in conjunctival smears of 17 (24% babies, and 6 (35.29% of them were positive for other bacteria. Six babies and their mothers tested positive for C. trachomatis Ig G antibodies. At follow-up after 14 weeks, 6 (35.29% of the Chlamydia antigen-positive babies were found to have developed recurrent conjunctivitis. CONCLUSION: C. trachomatis is responsible for almost a quarter of all cases of neonatal conjunctivitis, with recurrences in 35% of cases. Bacteria could be isolated from 50% of the patients though the exact role of Staphylococcus epidermidis, isolated from 28.65% of the neonatal conjunctivitis cases, remains unclear.

Chlamydia trachomatis Antibody Testing in Vaginal Mucosal Material versus Blood Samples of Women Attending a Fertility Clinic and an STI Clinic

NARCIS (Netherlands)

van den Broek, I.V.F.; Land, J.A.; van Bergen, J.E.A.M.; Morré, S.A.; van der Sande, M.A.B.

2014-01-01

Background. Chlamydia infections often follow an asymptomatic course but may damage the reproductive tract. Chlamydia antibodies in serum are used as markers for past infections and can relate to tubal pathology and infertility. This "proof of principle" study aimed to assess whether Chlamydia

An optimized, fast-to-perform mouse lung infection model with the human pathogen Chlamydia trachomatis for in vivo screening of antibiotics, vaccine candidates and modified host-pathogen interactions.

Science.gov (United States)

Dutow, Pavel; Wask, Lea; Bothe, Miriam; Fehlhaber, Beate; Laudeley, Robert; Rheinheimer, Claudia; Yang, Zhangsheng; Zhong, Guangming; Glage, Silke; Klos, Andreas

2016-03-01

Chlamydia trachomatis causes sexually transmitted diseases with infertility, pelvic inflammatory disease and neonatal pneumonia as complications. The duration of urogenital mouse models with the strict mouse pathogen C. muridarum addressing vaginal shedding, pathological changes of the upper genital tract or infertility is rather long. Moreover, vaginal C. trachomatis application usually does not lead to the complications feared in women. A fast-to-perform mouse model is urgently needed to analyze new antibiotics, vaccine candidates, immune responses (in gene knockout animals) or mutants of C. trachomatis. To complement the valuable urogenital model with a much faster and quantifiable screening method, we established an optimized lung infection model for the human intracellular bacterium C. trachomatis serovar D (and L2) in immunocompetent C57BL/6J mice. We demonstrated its usefulness by sensitive determination of antibiotic effects characterizing advantages and limitations achievable by early or delayed short tetracycline treatment and single-dose azithromycin application. Moreover, we achieved partial acquired protection in reinfection with serovar D indicating usability for vaccine studies, and showed a different course of disease in absence of complement factor C3. Sensitive monitoring parameters were survival rate, body weight, clinical score, bacterial load, histological score, the granulocyte marker myeloperoxidase, IFN-γ, TNF-α, MCP-1 and IL-6. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Usefulness of primary care electronic networks to assess the incidence of chlamydia, diagnosed by general practitioners.

NARCIS (Netherlands)

Suijkerbuijk, A.W.M.; Broek, I.V.F. van den; Brouwer, H.J.; Vanrolleghem, A.M.; Joosten, J.H.K.; Verheij, R.A.; Sande, M.A.B. van der; Kretzschmar, M.E.E.

2011-01-01

BACKGROUND: Chlamydia is the most common curable sexually transmitted infection (STI) in the Netherlands. The majority of chlamydia diagnoses are made by general practitioners (GPs). Baseline data from primary care will facilitate the future evaluation of the ongoing large population-based screening

Seroevidence of Chlamydia Trachomatis Antibody in Infertile Women in University of Benin Teaching Hospital (Ubth Benin City, Nigeria

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Ibadin, K. O.

2010-01-01

Full Text Available The role of Chlamydia trachomatis in the pathogenesis of Pelvic inflammatory disease and majority of cases of salpinigitis are well acknowledged in women. A total of 213 sera from infertile women were tested for antibodies to Chlamydia trachomatis by using an indirect solid phases enzyme Immuno absorbent commercial ELISA test. Women with confirmed Hysterosalpinographic report suggesting tubal occlusion (tubal factor infertility had 92 (43.2% followed by 63 (29.6% infertile women with infertile male partner and 58 (27.2% were having unexplained infertility. Out of the tubal factor (TF infertile women 40 (18.8% were seropositive for Chlamydia trachomatis antibodies, as against 19 (8.9% in the group of women with normal patent tubes and 10 (4.6% women with infertile male partner. In this study there was a statistical significant correlation between the infertile women with tubal factor infertility in relation to seroevidence of Chlamydia trachomatis infection with p<0.05. There was no age bias in the serodetection of Chlamydia trachomatis antibodies. The seropositivity of Chlamydia trachomatis is an indication that the organism may be an independent risk factor in the development of an inflammatory process leading to scaring of the uterine tubes in women and thereby causing infertility.

Striking ethnic variations in the epidemiology of Chlamydia trachomatis in Haifa District, Israel, throughout the years 2001-2015.

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Kridin, Khalaf; Khamaisi, Mogher; Rishpon, Shmuel; Grifat, Rami

2017-12-01

Our objectives were to examine trends in the incidence of chlamydia over an extended period and compare the epidemiology of the infection between two distinct ethnic groups in Israel: Jews and Arabs. We examined the incidence rate of Chlamydia trachomatis infection among residents of Haifa District, northern Israel from 2001 to 2015, by reviewing archives of the Department of Epidemiology, Ministry of Health. Notified cases were stratified by age group, gender, and ethnic group. The overall incidence rate of Chlamydia was 10.8 cases per 100,000 population per year. The annual rate increased dramatically from 5.1 per 100,000 population in 2001, to an all-time high of 18.5 cases per 100,000 population in 2015 (P < 0.001), representing an increase of 362.7%. The most affected age group was 25-34 years of age. The estimated rate among Jewish inhabitants was ninefold higher than among Arabs. Only 3% recurrent episodes of Chlamydia were registered. The prevalence of HIV positivity among Chlamydia-infected patients was similar to that of the general population. In conclusion, Chlamydia in Haifa has been continuously increasing since 2001 and the infection is much more prevalent among patients of Jewish ethnicity, mainly due to more hazardous sexual practices in this population.

High Titers of Chlamydia trachomatis Antibodies in Brazilian Women with Tubal Occlusion or Previous Ectopic Pregnancy

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A. C. S. Machado

2007-01-01

Full Text Available Objective. To evaluate serum chlamydia antibody titers (CATs in tubal occlusion or previous ectopic pregnancy and the associated risk factors. Methods. The study population consisted of 55 women wih tubal damage and 55 parous women. CAT was measured using the whole-cell inclusion immunofluorescence test and cervical chlamydial DNA detected by PCR. Odds ratios were calculated to assess variables associated with C. trachomatis infection. Results. The prevalence of chlamydial antibodies and antibody titers in women with tubal occlusion or previous ectopic pregnancy was significantly higher (P<.01 than in parous women. Stepwise logistic regression analysis showed that chlamydia IgG antibodies were associated with tubal damage and with a larger number of lifetime sexual partners. Conclusions. Chlamydia antibody titers were associated with tubal occlusion, prior ectopic pregnancy, and with sexual behavior, suggesting that a chlamydia infection was the major contributor to the tubal damage in these women.

Delivery of chlamydia screening to young women requesting emergency hormonal contraception at pharmacies in Manchester, UK: a prospective study

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O'Brien Karen

2009-03-01

Full Text Available Abstract Background More women are requesting Emergency Hormonal Contraception (EHC at pharmacies where screening for Chlamydia trachomatis is not routinely offered. The objective of this study was to assess the uptake of free postal chlamydia screening by women under 25 years who requested EHC at pharmacies in Manchester, UK. Methods Six Primary Care Trusts (PCTs that had contracted with pharmacies to provide free EHC, requested the largest EHC providers (≥ 40 doses annually to also offer these clients a coded chlamydia home testing kit. Pharmacies kept records of the ages and numbers of women who accepted or refused chlamydia kits. Women sent urine samples directly to the laboratory for testing and positive cases were notified. Audit data on EHC coverage was obtained from PCTs to assess the proportion of clients eligible for screening and to verify the uptake rate. Results 33 pharmacies participated. Audit data for 131 pharmacy months indicated that only 24.8% (675/2718 of women provided EHC were also offered chlamydia screening. Based on tracking forms provided by pharmacies for the whole of the study, 1348/2904 EHC clients (46.4% who had been offered screening accepted a screening kit. 264 (17.6% of those who accepted a kit returned a sample, of whom 24 (9.1% were chlamydia-positive. There was an increase in chlamydia positivity with age (OR: 1.2 per year; 1.04 to 1.44; p = 0.015. Conclusion Chlamydia screening for EHC pharmacy clients is warranted but failure of pharmacists to target all EHC clients represented a missed opportunity for treating a well defined high-risk group.

Molecular detection of Chlamydia trachomatis and Neisseria gonorrhoeae

DEFF Research Database (Denmark)

Møller, Jens Kjølseth; Herrmann, B; Jensen, K.T.

2011-01-01

This chapter highlights the use of nucleic acid amplification tests (NAATs) for the molecular diagnosis of gonorrhoea and chlamydia infection. In addition, good laboratory practice and issues that should be considered before and after implementation of NAATs for C. trachomatis and N. gonorrhoeae...

T Lymphocyte Immunity in Host Defence against Chlamydia trachomatis and Its Implication for Vaccine Development

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X Yang

1998-01-01

Full Text Available Chlamydia trachomatis is an obligate intracellular bacterial pathogen that causes several significant human infectious diseases, including trachoma, urethritis, cervicitis and salpingitis, and is an important cofactor for transmission of human immunodeficiency virus. Until very recently, over three decades of research effort aimed at developing a C trachomatis vaccine had failed, due mainly to the lack of a precise understanding of the mechanisms for protective immunity. Although most studies concerning protective immunity to C trachomatis have focused on humoral immune responses, recent studies have clearly shown that T helper-1 (Th1-like CD4 T cell-mediated immune responses play the dominant role in protective immunity. These studies suggest a paradigm for chlamydial immunity and pathology based on the concept of heterogeneity (Th1/Th2 in CD4 T cell immune responses. This concept for chlamydial immunity offers a rational template on which to base renewed efforts for development of a chlamydial vaccine that targets the induction of cell-mediated Th1 immune responses.

Three Antagonistic Cyclic di-GMP-Catabolizing Enzymes Promote Differential Dot/Icm Effector Delivery and Intracellular Survival at the Early Steps of Legionella pneumophila Infection

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Allombert, Julie; Lazzaroni, Jean-Claude; Baïlo, Nathalie; Gilbert, Christophe; Charpentier, Xavier; Doublet, Patricia

2014-01-01

Legionella pneumophila is an intracellular pathogen which replicates within protozoan cells and can accidently infect alveolar macrophages, causing an acute pneumonia in humans. The second messenger cyclic di-GMP (c-di-GMP) has been shown to play key roles in the regulation of various bacterial processes, including virulence. While investigating the function of the 22 potential c-di-GMP-metabolizing enzymes of the L. pneumophila Lens strain, we found three that directly contribute to its ability to infect both protozoan and mammalian cells. These three enzymes display diguanylate cyclase (Lpl0780), phosphodiesterase (Lpl1118), and bifunctional diguanylate cyclase/phosphodiesterase (Lpl0922) activities, which are all required for the survival and intracellular replication of L. pneumophila. Mutants with deletions of the corresponding genes are efficiently taken up by phagocytic cells but are partially defective for the escape of the Legionella-containing vacuole (LCV) from the host degradative endocytic pathway and result in lower survival. In addition, Lpl1118 is required for efficient endoplasmic reticulum recruitment to the LCV. Trafficking and biogenesis of the LCV are dependent upon the orchestrated actions of several type 4 secretion system Dot/Icm effectors proteins, which exhibit differentially altered translocation in the three mutants. While translocation of some effectors remained unchanged, others appeared over- and undertranslocated. A general translocation offset of the large repertoire of Dot/Icm effectors may be responsible for the observed defects in the trafficking and biogenesis of the LCV. Our results suggest that L. pneumophila uses cyclic di-GMP signaling to fine-tune effector delivery and ensure effective evasion of the host degradative pathways and establishment of a replicative vacuole. PMID:24379287

Unusual Self-Assembly of the Recombinant Chlamydia trachomatis Major Outer Membrane Protein-Based Fusion Antigen CTH522 Into Protein Nanoparticles

DEFF Research Database (Denmark)

Rose, Fabrice; Karlsen, Kasper; Jensen, Pernille

2018-01-01

Sexually transmitted Chlamydia trachomatis (Ct) infects more than 100 million people annually, and untreated chlamydia infections can cause severe complications. Therefore, there is an urgent need for a chlamydia vaccine. The Ct major outer membrane protein (MOMP) is highly immunogenic but is a c......Sexually transmitted Chlamydia trachomatis (Ct) infects more than 100 million people annually, and untreated chlamydia infections can cause severe complications. Therefore, there is an urgent need for a chlamydia vaccine. The Ct major outer membrane protein (MOMP) is highly immunogenic...... but is a challenging vaccine candidate by being an integral membrane protein, and the immunogenicity depends on a correctly folded structure. We investigated the biophysical properties of the recombinant MOMP-based fusion antigen CTH522, which is tested in early human clinical trials. It consists of a truncated......-defined secondary structural elements, and no thermal transitions were measurable. Chemical unfolding resulted monomers that upon removal of the denaturant self-assembled into higher order structures, comparable to the structure of the native protein. The conformation of CTH522 in nanoparticles is thus not entirely...

An α-Helical Core Encodes the Dual Functions of the Chlamydial Protein IncA*

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Ronzone, Erik; Wesolowski, Jordan; Bauler, Laura D.; Bhardwaj, Anshul; Hackstadt, Ted; Paumet, Fabienne

2014-01-01

Chlamydia is an intracellular bacterium that establishes residence within parasitophorous compartments (inclusions) inside host cells. Chlamydial inclusions are uncoupled from the endolysosomal pathway and undergo fusion with cellular organelles and with each other. To do so, Chlamydia expresses proteins on the surface of the inclusion using a Type III secretion system. These proteins, termed Incs, are located at the interface between host and pathogen and carry out the functions necessary for Chlamydia survival. Among these Incs, IncA plays a critical role in both protecting the inclusion from lysosomal fusion and inducing the homotypic fusion of inclusions. Within IncA are two regions homologous to eukaryotic SNARE (soluble N-ethylmaleimide-sensitive factor attachment receptor) domains referred to as SNARE-like domain 1 (SLD1) and SNARE-like domain 2 (SLD2). Using a multidisciplinary approach, we have discovered the functional core of IncA that retains the ability to both inhibit SNARE-mediated fusion and promote the homotypic fusion of Chlamydia inclusions. Circular dichroism and analytical ultracentrifugation experiments show that this core region is composed almost entirely of α-helices and assembles into stable homodimers in solution. Altogether, we propose that both IncA functions are encoded in a structured core domain that encompasses SLD1 and part of SLD2. PMID:25324548

Cost-effectiveness of Chlamydia Vaccination Programs for Young Women

Centers for Disease Control (CDC) Podcasts

2015-06-19

Dr. Kwame Owusu-Edusei discusses the importance of chlamydia vaccine development.  Created: 6/19/2015 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 6/22/2015.

Molecular characterisation and expression analysis of interferon gamma in response to natural Chlamydia infection in the koala, Phascolarctos cinereus.

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Mathew, Marina; Pavasovic, Ana; Prentis, Peter J; Beagley, Kenneth W; Timms, Peter; Polkinghorne, Adam

2013-09-25

Interferon gamma (IFNγ) is a key Th1 cytokine, with a principal role in the immune response against intracellular organisms such as Chlamydia. Along with being responsible for significant morbidity in human populations, Chlamydia is also responsible for wide spread infection and disease in many animal hosts, with reports that many Australian koala subpopulations are endemically infected. An understanding of the role played by IFNγ in koala chlamydial diseases is important for the establishment of better prophylactic and therapeutic approaches against chlamydial infection in this host. A limited number of IFNγ sequences have been published from marsupials and no immune reagents to measure expression have been developed. Through preliminary analysis of the koala transcriptome, we have identified the full coding sequence of the koala IFNγ gene. Transcripts were identified in spleen and lymph node tissue samples. Phylogenetic analysis demonstrated that koala IFNγ is closely related to other marsupial IFNγ sequences and more distantly related to eutherian mammals. To begin to characterise the role of this important cytokine in the koala's response to chlamydial infection, we developed a quantitative real time PCR assay and applied it to a small cohort of koalas with and without active chlamydial disease, revealing significant differences in expression patterns between the groups. Description of the IFNγ sequence from the koala will not only assist in understanding this species' response to its most important pathogen but will also provide further insight into the evolution of the marsupial immune system. Copyright © 2013 Elsevier B.V. All rights reserved.

Investigations concerning the prevalence of Coxiella burnetii and Chlamydia abortus in sheep in correlation with management systems and abortion rate in Lower Saxony in 2004.

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Runge, Martin; Binder, Alfred; Schotte, Ulrich; Ganter, Martin

2012-01-01

The intracellular bacteria Coxiella (C) burnetii and Chlamydia (Chl) abortus induce abortion in sheep and also affect humans. While Chl. abortus only infrequently infects humans, C burnetii is the aetiological agent of numerous Q fever outbreaks during the last decades. There is only limited knowledge about the prevalence of both pathogens in sheep, although sheep are involved in almost all Q fever outbreaks in Germany. The aim of our study was to investigate the prevalence of both pathogens in flocks located in Lower Saxony, Germany, in correlation to the management form and abortion rate. Serum samples of 1714 sheep from 95 flocks located in Lower Saxony were investigated by ELISA. 2.7% of these samples were positive, 1.3% showed inconclusive results in the C. burnetii-ELISA. Elevated intra-flock seroprevalences were only detected in three migrating flocks. Chlamydia-specific antibodies could be detected in 15.1% serum samples of mainly shepherded and migrating flocks. In one of these flocks with a high intra-flock seroprevalence for C burnetii (27%) and Chlamydia (44.9%), C burnetii was detected in 21.6% of the placenta samples of normal births and in 12.5% of the colostrum samples by PCR. Aborted fetuses and the corresponding placentas were negative in C burnetii-PCR, but in most of them and also in many other placenta samples Chl. abortus could be detected by PCR and DNA microarray. This survey shows a low overall prevalence of C. burnetii in sheep in Lower Saxony in the year 2004. However, three migrating flocks with a high intra-flock prevalence are localized in the southern parts of Lower Saxony. Spreading of C burnetii could occur, because of the large radius of grazing of all three flocks.

Considerations for the rational design of a Chlamydia vaccine.

Science.gov (United States)

Liang, Steven; Bulir, David; Kaushic, Charu; Mahony, James

2017-04-03

Chlamydia trachomatis is the leading cause of preventable blindness and the most common bacterial sexually transmitted infection. Remarkable progress in vaccine research over the past six decades has led to the advancement of novel C. trachomatis vaccine candidates into clinical trials. However, many questions regarding the role of specific cellular populations and molecular mechanisms in protective immunity against human C. trachomatis genital tract infections remain unanswered. Biomarkers of vaccine induced protective immunity are elusive in humans, while a cautionary message on the translatability of data obtained from current animal models has emanated from vaccine research and development efforts against other important human pathogens. In this commentary, we highlight recent advances in Chlamydia vaccine development and discuss their implications in the context of a rational approach to the design of a human C. trachomatis vaccine.

Typing of Lymphogranuloma Venereum Chlamydia trachomatis Strains

Science.gov (United States)

Christerson, Linus; de Vries, Henry J.C.; de Barbeyrac, Bertille; Gaydos, Charlotte A.; Henrich, Birgit; Hoffmann, Steen; Schachter, Julius; Thorvaldsen, Johannes; Vall-Mayans, Martí; Klint, Markus; Morré, Servaas A.

2010-01-01

We analyzed by multilocus sequence typing 77 lymphogranuloma venereum Chlamydia trachomatis strains from men who have sex with men in Europe and the United States. Specimens from an outbreak in 2003 in Europe were monoclonal. In contrast, several strains were in the United States in the 1980s, including a variant from Europe. PMID:21029543

Chlamydia species in free-living Cattle Egret (Bubulcus ibis and Hoopoe (Upupa epops in Egypt

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Jakeen K. El-Jakee

2014-06-01

Full Text Available Little information is available on the presence of chlamydia infection in wildlife. This study was conducted to assess the occurrence of chlamydiae in asymptomatic birds from two species of wild birds (Cattle Egret and Hoopoe in Egypt. In the present study Chlamydiaceae was analyzed using Giemsa stain, Giménez stain, fluorescent antibody test (FAT and PCR. The results of these techniques were compared with CFT for detecting Chlamydia psittaci antibodies among the examined birds. The results reveal that 96.4%, 81.8%, 89.1%, 80.0% and 58.2% of the examined samples were positive for chlamydiosis using PCR, Giemsa stain, Giménez stain, FA, and CFT respectively among Hoopoe. The percentages were 90.6%, 77.4%, 83.0%, 75.5% and 66.0% respectively for the previous tests among Cattle Egret birds. The results suggest that Cattle Egret and Hoopoe may be reservoir of Chlamydiaceae species and thus shed the organisms in their excreta. The shedding of chlamydiae by free living birds in Egypt may expose humans that come in contact with these birds to zoonotic risks.

Forekomst af Chlamydia trachomatis hos værnepligtige

DEFF Research Database (Denmark)

Søgaard, P; Møller, B R; Thorsen, Poul

1996-01-01

among Chlamydia positive men was 6. The frequency of earlier VD was 7.5% and 10% among men and women, respectively. Treatment with tetracycline was effective, which makes control of eradication unnecessary. We conclude that genital chlamydial infection among young asymptomatic people is common...

Follicular Conjunctivitis due to Chlamydia felis-Case Report, Review of the Literature and Improved Molecular Diagnostics.

Science.gov (United States)

Wons, Juliana; Meiller, Ralph; Bergua, Antonio; Bogdan, Christian; Geißdörfer, Walter

2017-01-01

A 29-year-old woman presented with unilateral, chronic follicular conjunctivitis since 6 weeks. While the conjunctival swab taken from the patient's eye was negative in a Chlamydia (C.) trachomatis -specific PCR, C. felis was identified as etiological agent using a pan- Chlamydia TaqMan-PCR followed by sequence analysis. A pet kitten of the patient was found to be the source of infection, as its conjunctival and pharyngeal swabs were also positive for C. felis . The patient was successfully treated with systemic doxycycline. This report, which presents one of the few documented cases of human C. felis infection, illustrates that standard PCR tests are designed to detect the most frequently seen species of a bacterial genus but might fail to be reactive with less common species. We developed a modified pan- Chlamydia / C. felis duplex TaqMan-PCR assay that detects C. felis without the need of subsequent sequencing. The role of chlamydiae-specific serum antibody titers for the diagnosis of follicular conjunctivitis is discussed.

The occurrence of Chlamydia spp. in pigs with and without clinical disease

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Englund Stina

2012-01-01

Full Text Available Abstract Background Within the genera Chlamydia, the development of refined diagnostic techniques has allowed the identification of four species that are capable of infecting pigs. The epidemiology, clinical, and zoonotic impacts of these species are however largely unknown. The study aimed to investigate the presence of Chlamydia spp. in the intestines of growing pigs and in conjunctival swabs from finisher pigs, and relate the findings to clinical signs. Results By histology, 20 of 48 pigs had intestinal lesions that may be consistent with chlamydial infection. By PCR, forty-six of the pigs were positive whereas two samples were inhibited. Sequencing of 19 DNA extracts identified these as Chlamydia suis. By immunohistochemistry, 32 of 44 samples were positive and a significant relationship was detected between macroscopically visible intestinal lesions and a high degree of infection. By real-time PCR, a significant difference was detected between pigs with and without conjunctivitis when a Ct value of 36 was employed but not when a Ct value of 38 was employed. Conclusions Chlamydia suis was demonstrated in most samples and overall, no correlation to clinical signs was detected. However, a correlation was noted between samples with a high degree of infection and the presence of clinical signs. It is possible, that the intensive pig production systems studied might predispose for the transmission and maintenance of the infection thus increasing the infectious load and the risk for disease in the pig.

Reduction of intracellular glutathione content and radiosensitivity

International Nuclear Information System (INIS)

Vos, O.; Schans, G.P. van der; Roos-Verheij, W.S.D.

1986-05-01

The intracellular glutathione (GSH) content in HeLa, CHO and V79 cells was reduced by incubating the cells in growth medium containing buthionine sulfoximine (BSO) or diethyl maleate (DEM). Clonogenicity, single strand DNA breaks (ssb) and double strand DNA breaks (dsb) were used as criteria for radiation induced damage after X- or γ irradiation. In survival experiments DEM gave a slightly larger sensitization although it gave a smaller reduction of the intracellular GSH. In general, sensitization was larger for dsb than for ssb, also the reduction of the OER was generally larger for dsb than for ssb. This may be due to the higher dose rate in case of dsb experiments resulting in a higher rate of radiochemical oxygen consumption. In general, no effect was found on post-irradiation repair of ssb and dsb. (Auth.)

Reduction of intracellular glutathione content and radiosensitivity

International Nuclear Information System (INIS)

Vos, O.; Schans, G.P. van der; Roos-Verheij, W.S.D.

1986-01-01

The intracellular glutathione (GSH) content of HeLa, CHO and V79 cells was reduced by incubating the cells in growth medium containing buthionine sulphoximine or diethyl maleate (DEM). Clonogenicity, single-strand DNA breaks (ssb) and double-strand DNA breaks (dsb) were used as criteria for radiation-induced damage after X- or γ-irradiation. In survival experiments, DEM gave a slightly larger sensitization although it gave a smaller reduction of the intracellular GSH. In general, sensitization was larger for dsb than for ssb, also the reduction of the o.e.r. was generally larger for dsb than for ssb. This may be due to the higher dose rate in case of dsb experiments resulting in a higher rate of radiochemical oxygen consumption. In general, no effect was found on post-irradiation repair of ssb and dsb. (author)

Association of chloride intracellular channel 4 and Indian hedgehog proteins with survival of patients with pancreatic ductal adenocarcinoma.

Science.gov (United States)

Zou, Qiong; Yang, Zhulin; Li, Daiqiang; Liu, Ziru; Yuan, Yuan

2016-12-01

Pancreatic cancer is the fourth most common cause of cancer-related mortality. Novel molecular biomarkers need to be identified for personalized medicine and to improve survival. The aim of this study was to examine chloride intracellular channel 4 (CLIC4) and Indian Hedgehog (Ihh) expression in benign and malignant lesions of the pancreas and to examine the eventual association between CLIC4 and Ihh expression, with clinicopathological features and prognosis of pancreatic cancer. A retrospective study of specimens collected from January 2000 to December 2011 at the Department of Pathology of the Second and Third Xiangya Hospitals, Central South University was undertaken to explore this question. Immunohistochemistry of CLIC4 and Ihh was performed with EnVision ™ in 106 pancreatic ductal adenocarcinoma specimens, 35 paracancer samples (2 cm away from the tumour, when possible or available), 55 benign lesions and 13 normal tissue samples. CLIC4 and Ihh expression in pancreatic ductal adenocarcinoma were significantly higher than in paracancer tissue and benign lesions (CLIC4: P = 0.009 and Ihh: P Ihh: P = 0.0001 respectively). CLIC4 and Ihh expression was negative in normal pancreatic tissues. The expression of CLIC4 and Ihh was associated significantly with tumour grade, lymph node metastasis, tumour invasion and poor overall survival. Thus CLIC4 and Ihh could serve as biological markers for the progression, metastasis and/or invasiveness of pancreatic ductal adenocarcinoma. © 2017 The Authors. International Journal of Experimental Pathology © 2017 International Journal of Experimental Pathology.

Chlamydia pneumoniae acute liver infection affects hepatic cholesterol and triglyceride metabolism in mice.

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Marangoni, Antonella; Fiorino, Erika; Gilardi, Federica; Aldini, Rita; Scotti, Elena; Nardini, Paola; Foschi, Claudio; Donati, Manuela; Montagnani, Marco; Cevenini, Monica; Franco, Placido; Roda, Aldo; Crestani, Maurizio; Cevenini, Roberto

2015-08-01

Chlamydia pneumoniae has been linked to atherosclerosis, strictly associated with hyperlipidemia. The liver plays a central role in the regulation of lipid metabolism. Since in animal models C. pneumoniae can be found at hepatic level, this study aims to elucidate whether C. pneumoniae infection accelerates atherosclerosis by affecting lipid metabolism. Thirty Balb/c mice were challenged intra-peritoneally with C. pneumoniae elementary bodies and thirty with Chlamydia trachomatis, serovar D. Thirty mice were injected with sucrose-phosphate-glutamate buffer, as negative controls. Seven days after infection, liver samples were examined both for presence of chlamydia and expression of genes involved in inflammation and lipid metabolism. C. pneumoniae was isolated from 26 liver homogenates, whereas C. trachomatis was never re-cultivated (P triglycerides levels compared both with negative controls (P metabolism. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Infección por Chlamydia trachomatis en usuarias de dos clínicas de planificación familiar Chlamydia trachomatis infection in users of two family planning clinics

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Thelma Canto-de Cetina

2003-01-01

Full Text Available OBJETIVO: Determinar la prevalencia de infección por Chlamydia trachomatis en mujeres que acuden a dos clínicas de planificación familiar. MATERIAL Y MÉTODOS: Se llevó a cabo un estudio transversal en 1 100 mujeres sexualmente activas, aparentemente sanas, de Mérida, Yucatán, México, quienes acudieron a dos clínicas de planificación familiar en el periodo comprendido de enero a diciembre de 1998. Las mujeres incluidas en el estudio tuvieron entre 15 y 45 años de edad, y habían estado libres de tratamiento antibacteriano al menos durante el mes previo a su inclusión. Se obtuvieron muestras endocervicales y datos epidemiológicos. La detección de bacterias fue realizada por el método inmunoenzimático de marca Wellcozyme. Los datos fueron procesados en el programa EPI Info. Como métodos estadísticos se utilizaron la prueba de Z, ji cuadrada y como medida de asociación, la razón de prevalencias. RESULTADOS: Setenta y cuatro mujeres (6.7 % fueron positivas a infección por Chlamydia trachomatis. Cerca de 50% de las mujeres estuvo asintomática. No se encontró diferencia estadística entre la proporción de mujeres con y sin Chlamydia que tuvieron síntomas vulvovaginales; por el contrario, los cambios relacionados con cervicitis fueron más frecuentes en las pacientes infectadas. C trachomatis fue más frecuente en usuarias de anticonceptivos orales (8.3% comparadas con mujeres que no tenían método anticonceptivo (5.4%. CONCLUSIONES: Los resultados de este estudio confirman la alta prevalencia de infecciones asintomáticas y pone énfasis en la importancia de un diagnóstico oportuno para evitar secuelas.OBJECTIVE: To determine the prevalence of Chlamydia trachomatis in women attending two family planning clinics in Merida, Yucatan, Mexico. MATERIAL AND METHODS: From January to December 1998, a cross-sectional study was conducted in 1 100 sexually active women between 15 and 45 years of age. Study subjects had not received

Hospitalisations for pelvic inflammatory disease temporally related to a diagnosis of Chlamydia or gonorrhoea: a retrospective cohort study.

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Joanne Reekie

Full Text Available The presence and severity of pelvic inflammatory disease (PID symptoms are thought to vary by microbiological etiology but there is limited empirical evidence. We sought to estimate and compare the rates of hospitalisation for PID temporally related to diagnoses of gonorrhoea and chlamydia.All women, aged 15-45 years in the Australian state of New South Wales (NSW, with a diagnosis of chlamydia or gonorrhoea between 01/07/2000 and 31/12/2008 were followed by record linkage for up to one year after their chlamydia or gonorrhoea diagnosis for hospitalisations for PID. Standardised incidence ratios compared the incidence of PID hospitalisations to the age-equivalent NSW population.A total of 38,193 women had a chlamydia diagnosis, of which 483 were hospitalised for PID; incidence rate (IR 13.9 per 1000 person-years of follow-up (PYFU (95%CI 12.6-15.1. In contrast, 1015 had a gonorrhoea diagnosis, of which 45 were hospitalised for PID (IR 50.8 per 1000 PYFU, 95%CI 36.0-65.6. The annual incidence of PID hospitalisation temporally related to a chlamydia or gonorrhoea diagnosis was 27.0 (95%CI 24.4-29.8 and 96.6 (95%CI 64.7-138.8 times greater, respectively, than the age-equivalent NSW female population. Younger age, socio-economic disadvantage, having a diagnosis prior to 2005 and having a prior birth were also associated with being hospitalised for PID.Chlamydia and gonorrhoea are both associated with large increases in the risk of PID hospitalisation. Our data suggest the risk of PID hospitalisation is much higher for gonorrhoea than chlamydia; however, further research is needed to confirm this finding.

MRI as a Novel In Vivo Approach for Assessing Structural Changes of Chlamydia Pathology in a Mouse Model.

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Catherine D G Hines

Full Text Available Chlamydia trachomatis is among the most prevalent of sexually transmitted diseases. While Chlamydia infection is a reportable event and screening has increased over time, enhanced surveillance has not resulted in a reduction in the rate of infections, and Chlamydia infections frequently recur. The development of a preventative vaccine for Chlamydia may be the only effective approach for reducing infection and the frequency of pathological outcomes. Current vaccine research efforts involve time consuming and/or invasive approaches for assessment of disease state, and MRI presents a clinically translatable method for assessing infection and related pathology both quickly and non-invasively. Longitudinal T2-weighted MRI was performed over 63 days on both control or Chlamydia muridarum challenged mice, either with or without elementary body (EB immunization, and gross necropsy was performed on day 65. A scoring system was developed to assess the number of regions affected by Chlamydia pathology and was used to document pathology over time and at necropsy. The scoring system documented increasing incidence of pathology in the unimmunized and challenged mice (significantly greater compared to the control and EB immunized-challenged groups by 21 days post-challenge. No differences between the unchallenged and EB immunized-challenged mice were observed. MRI scores at Day 63 were consistently higher than gross necropsy scores at Day 65, although two of the three groups of mice showed no significant differences between the two techniques. In this work we describe the application of MRI in mice for the potential evaluation of disease pathology and sequelae caused by C. muridarum infection and this technique's potential for evaluation of vaccines for Chlamydia.

Global survey of mRNA levels and decay rates of Chlamydia trachomatis trachoma and lymphogranuloma venereum biovars

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Rita Ferreira

2017-07-01

Full Text Available Interpreting the intricate bacterial transcriptomics implies understanding the dynamic relationship established between de novo transcription and the degradation of transcripts. Here, we performed a comparative overview of gene expression levels and mRNA decay rates for different-biovar (trachoma and lymphogranuloma venereum strains of the obligate intracellular bacterium Chlamydia trachomatis. By using RNA-sequencing to measure gene expression levels at mid developmental stage and mRNA decay rates upon rifampicin-based transcription blockage, we observed that: i 60–70% of the top-50 expressed genes encode proteins with unknown function and proteins involved in “Translation, ribosomal structure and biogenesis” for all strains; ii the expression ranking by genes' functional categories was in general concordant among different-biovar strains; iii the median of the half-life time (t1/2 values of transcripts were 15–17 min, indicating that the degree of transcripts’ stability seems to correlate with the bacterial intracellular life-style, as these values are considerably higher than the ones observed in other studies for facultative intracellular and free-living bacteria; iv transcript decay rates were highly heterogeneous within each C. trachomatis strain and did not correlate with steady-state expression levels; v only at very few instances (essentially at gene functional category level was possible to unveil dissimilarities potentially underlying phenotypic differences between biovars. In summary, the unveiled transcriptomic scenario, marked by a general lack of correlation between transcript production and degradation and a huge inter-transcript heterogeneity in decay rates, likely reflects the challenges underlying the unique biphasic developmental cycle of C. trachomatis and its intricate interactions with the human host, which probably exacerbate the complexity of the bacterial transcription regulation.

Chlamydia trachomatis serotype A infections in the Amazon region of Brazil: prevalence, entry and dissemination

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Marluísa de Oliveira Guimarães Ishak

2015-04-01

Full Text Available INTRODUCTION: Chlamydia infection is associated with debilitating human diseases including trachoma, pneumonia, coronary heart disease and urogenital diseases. Serotypes of C. trachomatis show a fair correlation with the group of diseases they cause, and their distribution follows a well-described geographic pattern. Serotype A, a trachoma-associated strain, is known for its limited dissemination in the Middle East and Northern Africa. However, knowledge on the spread of bacteria from the genus Chlamydia as well as the distribution of serotypes in Brazil is quite limited. METHODS: Blood samples of 1,710 individuals from ten human population groups in the Amazon region of Brazil were examined for antibodies to Chlamydia using indirect immunofluorescence and microimmunofluorescence assays. RESULTS: The prevalence of antibodies to Chlamydia ranged from 23.9% (Wayana-Apalai to 90.7% (Awa-Guaja with a mean prevalence of 50.2%. Seroreactivity was detected to C. pneumoniae and to all serotypes of C. trachomatis tested; furthermore, we report clear evidence of the as-yet-undescribed occurrence of serotype A of C. trachomatis. CONCLUSIONS: Specific seroreactivity not only accounts for the large extent of dissemination of C. trachomatis in the Amazon region of Brazil but also shows an expanded area of occurrence of serotype A outside the epidemiological settings previously described. Furthermore, these data suggest possible routes of Chlamydia introduction into the Amazon region from the massive human migration that occurred during the 1,700s.

Prediction of Chlamydia pneumoniae protein localization in host mitochondria and cytoplasm and possible involvements in lung cancer etiology: a computational approach

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Aws Alshamsan

2017-12-01

Full Text Available Collecting evidence suggests that the intercellular infection of Chlamydia pneumoniae in lungs contributes to the etiology of lung cancer. Many proteins of Chlamydia pneumoniae outmanoeuvre the various system of the host. The infection may regulate various factors, which can influence the growth of lung cancer in affected persons. In this in-silico study, we predict potential targeting of Chlamydia pneumoniae proteins in mitochondrial and cytoplasmic comportments of host cell and their possible involvement in growth and development of lung cancer. Various cellular activities are controlled in mitochondria and cytoplasm, where the localization of Chlamydia pneumoniae proteins may alter the normal functioning of host cells. The rationale of this study is to find out and explain the connection between Chlamydia pneumoniae infection and lung cancer. A sum of 183 and 513 proteins were predicted to target in mitochondria and cytoplasm of host cell out of total 1112 proteins of Chlamydia pneumoniae. In particular, many targeted proteins may interfere with normal growth behaviour of host cells, thereby altering the decision of program cell death. Present article provides a potential connection of Chlamydia pneumoniae protein targeting and proposed that various targeted proteins may play crucial role in lung cancer etiology through diverse mechanisms.

Using the theory of planned behaviour and self-identity to explain chlamydia testing intentions in young people living in deprived areas.

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Booth, Amy R; Norman, Paul; Harris, Peter R; Goyder, Elizabeth

2014-02-01

The study sought to (1) explain intentions to get tested for chlamydia regularly in a group of young people living in deprived areas using the theory of planned behaviour (TPB); and (2) test whether self-identity explained additional variance in testing intentions. A cross-sectional design was used for this study. Participants (N = 278, 53% male; M = 17.05 years) living in deprived areas of a UK city were recruited from a vocational education setting. Participants completed a self-administered questionnaire, including measures of attitude, injunctive subjective norm, descriptive norm, perceived behavioural control, self-identity, intention and past behaviour in relation to getting tested for chlamydia regularly. The TPB explained 43% of the variance in chlamydia testing intentions with all variables emerging as significant predictors. However, self-identity explained additional variance in intentions (ΔR(2)  = .22) and emerged as the strongest predictor, even when controlling for past behaviour. The study identified the key determinants of intention to get tested for chlamydia regularly in a sample of young people living in areas of increased deprivation: a hard-to-reach, high-risk population. The findings indicate the key variables to target in interventions to promote motivation to get tested for chlamydia regularly in equivalent samples, amongst which self-identity is critical. What is already known on this subject? Young people living in deprived areas have been identified as an at-risk group for chlamydia. Qualitative research has identified several themes in relation to factors affecting the uptake of chlamydia testing, which fit well with the constructs of the Theory of Planned Behaviour (TPB). Identity concerns have also been identified as playing an important part in young people's chlamydia testing decisions. What does this study add? TPB explained 43% of the variance in chlamydia testing intentions and all variables were significant predictors

Autophagic clearance of bacterial pathogens: molecular recognition of intracellular microorganisms.

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Pareja, Maria Eugenia Mansilla; Colombo, Maria I

2013-01-01

Autophagy is involved in several physiological and pathological processes. One of the key roles of the autophagic pathway is to participate in the first line of defense against the invasion of pathogens, as part of the innate immune response. Targeting of intracellular bacteria by the autophagic machinery, either in the cytoplasm or within vacuolar compartments, helps to control bacterial proliferation in the host cell, controlling also the spreading of the infection. In this review we will describe the means used by diverse bacterial pathogens to survive intracellularly and how they are recognized by the autophagic molecular machinery, as well as the mechanisms used to avoid autophagic clearance.

Development and validation of a real-time PCR for Chlamydia suis diagnosis in swine and humans.

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Kristien De Puysseleyr

Full Text Available Pigs are the natural host for Chlamydia suis, a pathogen which is phylogenetically highly related to the human pathogen C. trachomatis. Chlamydia suis infections are generally treated with tetracyclines. In 1998, tetracyline resistant C. suis strains emerged on U.S. pig farms and they are currently present in the Belgian, Cypriote, German, Israeli, Italian and Swiss pig industry. Infections with tetracycline resistant C. suis strains are mainly associated with severe reproductive failure leading to marked economical loss. We developed a sensitive and specific TaqMan probe-based C. suis real-time PCR for examining clinical samples of both pigs and humans. The analytical sensitivity of the real-time PCR is 10 rDNA copies/reaction without cross-amplifying DNA of other Chlamydia species. The PCR was successfully validated using conjunctival, pharyngeal and stool samples of slaughterhouse employees, as well as porcine samples from two farms with evidence of reproductive failure and one farm without clinical disease. Chlamydia suis was only detected in diseased pigs and in the eyes of humans. Positive humans had no clinical complaints. PCR results were confirmed by culture in McCoy cells. In addition, Chlamydia suis isolates were also examined by the tet(C PCR, designed for demonstrating the tetracycline resistance gene tet(C. The tet(C gene was only present in porcine C. suis isolates.

MicroRNA-155 promotes autophagy to eliminate intracellular mycobacteria by targeting Rheb.

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Wang, Jinli; Yang, Kun; Zhou, Lin; Minhaowu; Wu, Yongjian; Zhu, Min; Lai, Xiaomin; Chen, Tao; Feng, Lianqiang; Li, Meiyu; Huang, Chunyu; Zhong, Qiu; Huang, Xi

2013-01-01

Mycobacterium tuberculosis is a hard-to-eradicate intracellular pathogen that infects one-third of the global population. It can live within macrophages owning to its ability to arrest phagolysosome biogenesis. Autophagy has recently been identified as an effective way to control the intracellular mycobacteria by enhancing phagosome maturation. In the present study, we demonstrate a novel role of miR-155 in regulating the autophagy-mediated anti-mycobacterial response. Both in vivo and in vitro studies showed that miR-155 expression was significantly enhanced after mycobacterial infection. Forced expression of miR-155 accelerated the autophagic response in macrophages, thus promoting the maturation of mycobacterial phagosomes and decreasing the survival rate of intracellular mycobacteria, while transfection with miR-155 inhibitor increased mycobacterial survival. However, macrophage-mediated mycobacterial phagocytosis was not affected after miR-155 overexpression or inhibition. Furthermore, blocking autophagy with specific inhibitor 3-methyladenine or silencing of autophagy related gene 7 (Atg7) reduced the ability of miR-155 to promote autophagy and mycobacterial elimination. More importantly, our study demonstrated that miR-155 bound to the 3'-untranslated region of Ras homologue enriched in brain (Rheb), a negative regulator of autophagy, accelerated the process of autophagy and sequential killing of intracellular mycobacteria by suppressing Rheb expression. Our results reveal a novel role of miR-155 in regulating autophagy-mediated mycobacterial elimination by targeting Rheb, and provide potential targets for clinical treatment.

MicroRNA-155 promotes autophagy to eliminate intracellular mycobacteria by targeting Rheb.

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Jinli Wang

Full Text Available Mycobacterium tuberculosis is a hard-to-eradicate intracellular pathogen that infects one-third of the global population. It can live within macrophages owning to its ability to arrest phagolysosome biogenesis. Autophagy has recently been identified as an effective way to control the intracellular mycobacteria by enhancing phagosome maturation. In the present study, we demonstrate a novel role of miR-155 in regulating the autophagy-mediated anti-mycobacterial response. Both in vivo and in vitro studies showed that miR-155 expression was significantly enhanced after mycobacterial infection. Forced expression of miR-155 accelerated the autophagic response in macrophages, thus promoting the maturation of mycobacterial phagosomes and decreasing the survival rate of intracellular mycobacteria, while transfection with miR-155 inhibitor increased mycobacterial survival. However, macrophage-mediated mycobacterial phagocytosis was not affected after miR-155 overexpression or inhibition. Furthermore, blocking autophagy with specific inhibitor 3-methyladenine or silencing of autophagy related gene 7 (Atg7 reduced the ability of miR-155 to promote autophagy and mycobacterial elimination. More importantly, our study demonstrated that miR-155 bound to the 3'-untranslated region of Ras homologue enriched in brain (Rheb, a negative regulator of autophagy, accelerated the process of autophagy and sequential killing of intracellular mycobacteria by suppressing Rheb expression. Our results reveal a novel role of miR-155 in regulating autophagy-mediated mycobacterial elimination by targeting Rheb, and provide potential targets for clinical treatment.

Acute Glomerulonephritis in a Child with Chlamydia pneumoniae Infection: A Case Report

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Giovanna Vitaliti

2013-01-01

Full Text Available Background. Infectious diseases seem to be an important and independent risk factor for renal failure, but the underlying mechanism of renal involvement during some kinds of infectious diseases is still unclear, even if the literature data report immunomediated and/or autoimmune mechanisms to explain the pathogenic relationship between the two diseases. In paediatric patients, Chlamydia pneumoniae is a rare cause of renal complications and it may manifest in several ways, mainly involving the respiratory system, even if also renal and glomerulalr complications, have been described. Case Diagnosis/Treatment. Herein we report a case of a 3-year-old child who developed an acute glomerulonephritis that was chronologically, clinically, and biologically related to a previous Chlamydia pneumoniae infection. On our knowledge, in the literature it is the youngest patient with renal involvement during course of Chlamydia pneumoniae infection ever reported. Conclusions. The present case supports the hypothesis of a rather close causal relationship between this infective agent and renal and glomerular symptoms occurred in this child, during an acute episode of respiratory disease.

Systems Biology Approaches for the Prediction of Possible Role of Chlamydia pneumoniae Proteins in the Etiology of Lung Cancer.

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Shahanavaj Khan

Full Text Available Accumulating evidence has recently supported the association of bacterial infection with the growth and development of cancers, particularly in organs that are constantly exposed to bacteria such as the lungs, colon, cervical cancer etc. Our in silico study on the proteome of Chlamydia pneumoniae suggests an unprecedented idea of the etiology of lung cancer and have revealed that the infection of C. pneumoniae is associated with lung cancer development and growth. It is reasonable to assume that C. pneumoniae transports its proteins within host-intracellular organelles during infection, where they may work with host-cell proteome. The current study was performed for the prediction of nuclear targeting protein of C. pneumoniae in the host cell using bioinformatics predictors including ExPASy pI/Mw tool, nuclear localization signal (NLS mapper, balanced sub cellular localization predictor (BaCeILo, and Hum-mPLoc 2.0. We predicted 47/1112 nuclear-targeting proteins of C. pneumoniae connected with several possible alterations in host replication and transcription during intracellular infection. These nuclear-targeting proteins may direct to competitive interactions of host and C. pneumoniae proteins with the availability of same substrate and may be involved as etiological agents in the growth and development of lung cancer. These novel findings are expected to access in better understanding of lung cancer etiology and identifying molecular targets for therapy.

Readiness of pharmacists and consumers for pharmacy-based chlamydia screening in Australia and Switzerland.

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Arnet, Isabelle; Gudka, Sajni; Salter, Sandra; Hersberger, Kurt E; Clifford, Rhonda

2018-06-01

To assess chlamydia knowledge, willingness to undertake pharmacy-based chlamydia testing, and facilitators and barriers to such testing in consumers and community pharmacists, in Australia (AUS) and Switzerland (CH). Statements of interest were retrieved from literature and assembled into a 12-item online survey (English and German versions). Survey was disseminated through Facebook, pharmacies' publicly available emails and professional websites (March 2015). Consumers and pharmacists (AUS: n cons  = 198, n pharm  = 162; CH: n cons  = 209, n pharm  = 223) were predominantly female (>65%). Mean chlamydia knowledge scores (maximum of 8) were higher in Australia in consumers (AUS: 6.8 ± 1.5 vs CH: 4.2 ± 2.4; p business. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

Primary health care providers surveyed commonly misinterpret 'first void urine' for chlamydia screening.

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Lusk, M Josephine; Uddin, Ruby; Ferson, Mark; Rawlinson, William; Konecny, Pam

2009-03-01

An open question survey of general practitioners (GP) and hospital emergency department (ED) doctors revealed that the term 'FVU' (first void urine) used for urine chlamydia testing, is ambiguous, potentially leading to incorrect urine sample collection and barriers to effective screening. The results of this survey indicate that only 4.3% (95% confidence interval [CI] 0.5-14.5%) of GP and 6.9% (95% CI 0.9-22.8%) of ED doctors respectively, correctly interpreted the meaning of FVU. The majority of clinicians surveyed misunderstood 'FVU' to require the first urine void of the day, accounting for 68.1% (95% CI 52.9-80.9%) of GP responses and 37.9% (95% CI 20.7-57.7%) of ED doctors responses. This highlights the need for clarification and standardisation of terminology used in urine chlamydia screening for health care providers, in order to optimise strategies for diagnosis and control of the ongoing chlamydia epidemic.

Better than nothing? Patient-delivered partner therapy and partner notification for chlamydia: the views of Australian general practitioners

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Bowden Francis J

2010-09-01

Full Text Available Abstract Background Genital chlamydia is the most commonly notified sexually transmissible infection (STI in Australia and worldwide and can have serious reproductive health outcomes. Partner notification, testing and treatment are important facets of chlamydia control. Traditional methods of partner notification are not reaching enough partners to effectively control transmission of chlamydia. Patient-delivered partner therapy (PDPT has been shown to improve the treatment of sexual partners. In Australia, General Practitioners (GPs are responsible for the bulk of chlamydia testing, diagnosis, treatment and follow up. This study aimed to determine the views and practices of Australian general practitioners (GPs in relation to partner notification and PDPT for chlamydia and explored GPs' perceptions of their patients' barriers to notifying partners of a chlamydia diagnosis. Methods In-depth, semi-structured telephone interviews were conducted with 40 general practitioners (GPs from rural, regional and urban Australia from November 2006 to March 2007. Topics covered: GPs' current practice and views about partner notification, perceived barriers and useful supports, previous use of and views regarding PDPT. Transcripts were imported into NVivo7 and subjected to thematic analysis. Data saturation was reached after 32 interviews had been completed. Results Perceived barriers to patients telling partners (patient referral included: stigma; age and cultural background; casual or long-term relationship, ongoing relationship or not. Barriers to GPs undertaking partner notification (provider referral included: lack of time and staff; lack of contact details; uncertainty about the legality of contacting partners and whether this constitutes breach of patient confidentiality; and feeling both personally uncomfortable and inadequately trained to contact someone who is not their patient. GPs were divided on the use of PDPT - many felt concerned that it is not

Seroprevalence and risk factors of Chlamydia abortus infection in free-ranging white yaks in China.

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Qin, Si-Yuan; Huang, Si-Yang; Yin, Ming-Yang; Tan, Qi-Dong; Liu, Guang-Xue; Zhou, Dong-Hui; Zhu, Xing-Quan; Zhou, Ji-Zhang; Qian, Ai-Dong

2015-01-20

Chlamydia is gram-negative obligate bacteria which causes a wide variety of diseases in humans and animals. To date, there are a few reports about the seroprevalence of Chlamydia and the risk factors associated with Chlamydia infection in yaks in the world. In this study, 974 blood samples were collected from white yaks (Bos grunniens) in Tianzhu Tibetan Autonomous County, Gansu province, northwest China from June 2013 to April 2014. Antibodies against Chlamydia abortus were examined by the indirect hemagglutination (IHA) test, and 158 of 974 (16.22%) white yaks were seropositive for C. abortus antibodies at the cut-off of 1:16. The risk factors associated with seroprevalence were evaluated by a multivariate logistic regression analysis. Region, gender and age of white yak were left out of the final model, due to its insignificance in the logistic regression analysis (P > 0.05). However, season was considered as a major risk factor associated with C. abortus infection in white yaks. To our knowledge, this is the first survey of C. abortus seroprevalence in white yaks in China, which extends the host range for C. abortus and has important implications for public health and the local Tibetan economy.

Follicular Conjunctivitis due to Chlamydia felis—Case Report, Review of the Literature and Improved Molecular Diagnostics

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Juliana Wons

2017-07-01

Full Text Available A 29-year-old woman presented with unilateral, chronic follicular conjunctivitis since 6 weeks. While the conjunctival swab taken from the patient’s eye was negative in a Chlamydia (C. trachomatis-specific PCR, C. felis was identified as etiological agent using a pan-Chlamydia TaqMan-PCR followed by sequence analysis. A pet kitten of the patient was found to be the source of infection, as its conjunctival and pharyngeal swabs were also positive for C. felis. The patient was successfully treated with systemic doxycycline. This report, which presents one of the few documented cases of human C. felis infection, illustrates that standard PCR tests are designed to detect the most frequently seen species of a bacterial genus but might fail to be reactive with less common species. We developed a modified pan-Chlamydia/C. felis duplex TaqMan-PCR assay that detects C. felis without the need of subsequent sequencing. The role of chlamydiae-specific serum antibody titers for the diagnosis of follicular conjunctivitis is discussed.

Disappointing performance of literature-derived selective screening criteria for asymptomatic Chlamydia trachomatis infection in an inner-city population

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van Valkengoed, I G; Boeke, A J; Morré, S A; van den Brule, A J; Meijer, C J; Devillé, W; Bouter, L M

2000-01-01

BACKGROUND: In an inner-city population with a low prevalence of Chlamydia trachomatis infection, selective screening may be indicated to increase the efficiency of screening. GOAL: To evaluate the performance of sets of selective screening criteria for asymptomatic Chlamydia trachomatis infection

Dysbiosis of the Vaginal Microbiota and Higher Vaginal Kynurenine/Tryptophan Ratio Reveals an Association with Chlamydia trachomatis Genital Infections

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Noa Ziklo

2018-01-01

Full Text Available The natural course of Chlamydia trachomatis urogenital tract infections varies between individuals. While protective immunity can occur, some women can become reinfected, contributing to the development of severe pathology. While the reasons for these differences are unknown, an individual's response to induced interferon-γ (IFN-γ is suggested to be critical. IFN-γ induction of the enzyme indoleamine 2,3-dioxygenase, which depletes tryptophan, may be the key. One hypothesis suggests that indole-producing bacteria in the vaginal microbiota can provide a substrate for the Chlamydia to synthesize tryptophan, rescuing the Chlamydia from host IFN-γ attack. We studied a cohort of 25 women who were either, Chlamydia negative, Chlamydia positive with a single infection, or Chlamydia positive with repeated infection, to test our hypothesis. We characterized their vaginal microbiota, cytokine response, as well as their tryptophan, kynurenine and indole concentrations directly in vaginal secretions. We found that C. trachomatis urogenital tract infections either initial or repeat infections, were associated with elevated vaginal kynurenine/tryptophan ratios, primarily as a result of elevated kynurenine levels. In addition, vaginal microbiota of community state type (CST IV showed significantly lower vaginal tryptophan levels compared to CST I and III, which might be related to a higher abundance of indole producers found within this group. Furthermore, we found a higher abundance of indole producers in women who cleared their Chlamydia infection post antibiotic treatment. This study demonstrates for the first time in vivo, the association between high vaginal kynurenine/tryptophan ratios and C. trachomatis infections. In addition, tryptophan depletion was associated with vaginal microbiota of CST IV.

The laboratory diagnosis of Chlamydia trachomatis infections

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Max A Chernesky

2005-01-01

Full Text Available Lower genital tract infections with Chlamydia trachomatis are predominantly asymptomatic in men and women. Diagnostic technology has provided several approaches to the diagnosis of C trachomatis. Outside of cells, Chlamydia can die or degrade without optimal storage and transportation. Because some of the other assays perform better on certain specimen types, it is important for laboratories to recognize these differences and provide advice to physicians and nurses collecting patient specimens, with the objective of diagnosing lower genital tract infections to prevent transmission and upper tract damage. Most invasive specimens, such as cervical or urethral swabs, may be collected for culture, antigen or nucleic acid detection. Noninvasive samples such as first-void urine and vaginal swabs can be easily collected by the patient; these samples must be tested by more sensitive nucleic acid amplification tests. These newer investigative strategies should enable implementation of screening programs to identify and treat partners. Serology has not been particularly useful for the diagnosis of acute C trachomatis infections in adults. Presently, it appears that antibiotic-resistant C trachomatis is not a clinical problem. Laboratories providing C trachomatis diagnosis require participation in continuous quality improvement programs.

Peripheral Neuropathy in Chlamydia Reactive Arthritis

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O.V. Syniachenko

2016-09-01

Full Text Available Relevance. Peripheral neuropathy (PNP in urogenital chlamydia reactive arthritis (CRA is described as single observations, and many clinical and pathogenetic aspects of this lesion of the nervous system remain unclear. Objective of the study: to evaluate the incidence and nature of the clinical course of PNP in CRA, the connection of the nerve and joint injuries, to explore the questions of pathogenetic constructions of this neuropathy, to identify risk factors. Material and methods. We observed 101 patients with CRA, mean age of them was 32 years, disease duration — 4 years, and the male to female ratio — 1 : 1. In 90 % of CRA cases, Chlamydia trochamatis was found in prostatic secretions, in scraps from the urethra, the cervix, the vaginal wall, in 83 % — positive serologic tests for chlamydia infection. Results. Signs of PNP in CRA were in 19 % of patients in the ratio of mononeuropathy to polyneuropathy as 1 : 1, with motor, sensory and mixed disorders in a ratio of 1 : 3 : 6, the presence of autonomic changes in every second patient and more frequent distal localization of the process in the hands, which is influenced by the severity of the articular syndrome, high levels of antichlamydia antibodies in the blood, and the axonal and demyelinating indicators of electroneuromyography — by the severity of urogenital lesions and the presence of Guillain-Barre syndrome. A high rate of arthritis progression is a prognosis-negative sign of PNP course in patients with CRA. The pathogenic constructions of PNP involve the inflammatory immune proteins, disturbances of vascular endothelial function and physicochemical surface rheological pro­perties of the serum. Conclusion. PNP takes place in every fifth patient with CRA, correlates with clinical and laboratory signs of joint disease, and in the future will be useful to identify actively this pathology of the nervous system for the subsequent timely rehabilitation, and CRA

Chlamydia trachomatis infection and risk of cervical intraepithelial neoplasia

DEFF Research Database (Denmark)

Lehtinen, Matti; Ault, Kevin A; Lyytikainen, Erika

2011-01-01

High-risk human papillomavirus (hrHPV) is the primary cause of cervical cancer. As Chlamydia trachomatis is also linked to cervical cancer, its role as a potential co-factor in the development of cervical intraepithelial neoplasia (CIN) grade 2 or higher was examined....

The prevalence of Chlamydia trachomatis infection among infertile ...

African Journals Online (AJOL)

Chlamydia trachomatis is the most common cause of sexually transmitted diseases that is not of viral origin and there is accumulating evidence of a significant role played by this pathogen in causing male factor infertility. This study thus aimed to determine the prevalence of C. trachomatis among infertile males and to ...

Public health economics of chlamydia and other STIs : aspects of risk, prevention and resources

OpenAIRE

Deogan, Charlotte

2013-01-01

The overall aim of this thesis was to increase the knowledge of the public health economic aspects of chlamydia and other STIs, in terms of risk, prevention and resources. In Study I, we examined the association between demographic, socioeconomic and lifestyle factors and the risk of self-reported chlamydial infection among young adults in the Stockholm public health cohort. We found that the risk of self-reported chlamydia infection among young adults in Sweden was associated with lowe...

Identification and Partial Characterization of Potential FtsL and FtsQ Homologs of Chlamydia

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Scot P Ouellette

2015-11-01

Full Text Available Chlamydia is amongst the rare bacteria that lack the critical cell division protein FtsZ. By annotation, Chlamydia also lacks several other essential cell division proteins including the FtsLBQ complex that links the early (e.g. FtsZ and late (e.g. FtsI/Pbp3 components of the division machinery. Here, we report chlamydial FtsL and FtsQ homologs. Ct271 aligned well with E. coli FtsL and shared sequence homology with it, including a predicted leucine-zipper like motif. Based on in silico modeling, we show that Ct764 has structural homology to FtsQ in spite of little sequence similarity. Importantly, ct271/ftsL and ct764/ftsQ are present within all sequenced chlamydial genomes and are expressed during the replicative phase of the chlamydial developmental cycle, two key characteristics for a chlamydial cell division gene. GFP-Ct764 localized to the division septum of dividing transformed chlamydiae, and, importantly, over-expression inhibited chlamydial development. Using a bacterial two-hybrid approach, we show that Ct764 interacted with other components of the chlamydial division apparatus. However, Ct764 was not capable of complementing an E. coli FtsQ depletion strain in spite of its ability to interact with many of the same division proteins as E. coli FtsQ, suggesting that chlamydial FtsQ may function differently. We previously proposed that Chlamydia uses MreB and other rod-shape determining proteins as an alternative system for organizing the division site and its apparatus. Chlamydial FtsL and FtsQ homologs expand the number of identified chlamydial cell division proteins and suggest that Chlamydia has likely kept the late components of the division machinery while substituting the Mre system for the early components.

MRP8/14 induces autophagy to eliminate intracellular Mycobacterium bovis BCG.

Science.gov (United States)

Wang, Jinli; Huang, Chunyu; Wu, Minhao; Zhong, Qiu; Yang, Kun; Li, Miao; Zhan, Xiaoxia; Wen, Jinsheng; Zhou, Lin; Huang, Xi

2015-04-01

To explore the role of myeloid-related protein 8/14 in mycobacterial infection. The mRNA and protein expression levels of MRP8 or MRP14 were measured by real-time PCR and flow cytometry, respectively. Role of MRP8/14 was tested by overexpression or RNA interference assays. Flow cytometry and colony forming unit were used to test the phagocytosis and the survival of intracellular Mycobacterium bovis BCG (BCG), respectively. Autophagy mediated by MRP8/14 was detected by Western blot and immunofluorescence. The colocalization of BCG phagosomes with autophagosomes or lysosomes was by detected by confocal microscopy. ROS production was detected by flow cytometry. MRP8/14 expressions were up-regulated in human monocytic THP1 cells and primary macrophages after mycobacterial challenge. Silencing of MRP8/14 suppressed bacterial killing, but had no influence on the phagocytosis of BCG. Importantly, silencing MRP8/14 decreased autophagy and BCG phagosome maturation in THP1-derived macrophages, thereby increasing the BCG survival. Additionally, we demonstrated that MRP8/14 promoted autophagy in a ROS-dependent manner. The present study revealed a novel role of MRP8/14 in the autophagy-mediated elimination of intracellular BCG by promoting ROS generation, which may provide a promising therapeutic target for tuberculosis and other intracellular bacterial infectious diseases. Copyright © 2014 The British Infection Association. Published by Elsevier Ltd. All rights reserved.

Double trouble: modelling the impact of low risk perception and high-risk sexual behaviour on chlamydia transmission.

Science.gov (United States)

van Wees, Daphne A; den Daas, Chantal; Kretzschmar, Mirjam E E; Heijne, Janneke C M

2018-04-01

Risk perception plays an important role in testing behaviour for sexually transmitted infections, but is rarely included in mathematical models exploring the impact of testing. We explored the impact of incorporating sexual behaviour (SB), risk perception (RP) and differential testing uptake in SB-RP groups on prevalence, using chlamydia as an example. We developed a pair model with a susceptible-infected-susceptible structure representing heterosexuals aged 16-26 years. The effect of testing on chlamydia prevalence was compared between a model with only SB (SB model) and a model with SB and RP (SB-RP model). In the SB-RP model, a scenario without differential testing uptake in SB-RP groups was compared to scenarios with differential testing uptake in SB-RP groups. Introducing testing into the SB-RP model resulted in a slightly smaller reduction in chlamydia prevalence (-38.0%) as compared to the SB model (-40.4%). In the SB-RP model, the scenario without differential testing uptake in SB-RP groups overestimated the reduction in chlamydia prevalence (with 4.8%), especially in the group with high SB and low RP (19.8%). We conclude that mathematical models incorporating RP and differential testing uptake in SB-RP groups improve the impact assessment of testing and treatment on chlamydia prevalence. © 2018 The Author(s).

Chlamydia trachomatis and Chlamydophila abortus induce the expression of secretory leukocyte protease inhibitor in cells of the human female reproductive tract.

Science.gov (United States)

Wheelhouse, Nick; Wattegedera, Sean; Fleming, Diana; Fitch, Paul; Kelly, Rodney; Entrican, Gary

2008-09-01

C. trachomatis and C. abortus are related Gram-negative intracellular bacteria that cause reproductive failure due to infertility (C. trachomatis) or abortion (C. abortus). These organisms target epithelial cells in the reproductive tract and/or placenta, but the innate immune mechanisms that lead to protection or pathology and disease are poorly understood. SLPI is an innate immune molecule which protects mucosal surfaces from infection and injury. C. trachomatis and C. abortus were found to induce SLPI mRNA and peptide expression in HeLa (cervical epithelium) and JEG-3 cells (trophoblast) respectively. Both cell lines constitutively expressed SLPI and, although infection enhanced this expression, killed organisms did not. These data demonstrate that Chlamydia/Chlamydophila grow in cells that express SLPI, suggesting that SLPI does not exert antimicrobial effects against these organisms. However, SLPI has multiple functions, and we speculate that it may play a role in controlling tissue inflammation and pathology.

Chlamydia control in Europe - a survey of Member States

DEFF Research Database (Denmark)

Andersen, Berit; van Bergen, J; Ward, H

), contributed to the design and interpretation of the survey, commented on the draft report and approved the final report. Shelagh Redmond (Institute of Social and Preventive Medicine, University of Bern, Bern, Switzerland) provided technical support. Nicola Low (University of Bern) led the Chlamydia Control...

Association of Chlamydia serology with HIV in Nigerian women ...

African Journals Online (AJOL)

For an infection that is largely asymptomatic but has devastating effects on populations, only a preventive approach would have beneficial effects in controlling the disease and its effects on women's health in the country. Keywords: Chlamydia trachomatis, HIV, pregnant women, gynaecologic patients, co-infection ...

Association of anti-Chlamydia antibodies with ectopic pregnancy in ...

African Journals Online (AJOL)

Background: Ectopic pregnancy remains a major public health problem especially in many developing countries where it is a significant contributor to pregnancy related morbidity and mortality. Objective: To determine the association between prior Chlamydia trachomatis infection and the risk of ectopic pregnancy. Methods: ...

Processing of Chlamydia abortus polymorphic membrane protein 18D during the chlamydial developmental cycle.

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Nick M Wheelhouse

Full Text Available Chlamydia possess a unique family of autotransporter proteins known as the Polymorphic membrane proteins (Pmps. While the total number of pmp genes varies between Chlamydia species, all encode a single pmpD gene. In both Chlamydia trachomatis (C. trachomatis and C. pneumoniae, the PmpD protein is proteolytically cleaved on the cell surface. The current study was carried out to determine the cleavage patterns of the PmpD protein in the animal pathogen C. abortus (termed Pmp18D.Using antibodies directed against different regions of Pmp18D, proteomic techniques revealed that the mature protein was cleaved on the cell surface, resulting in a100 kDa N-terminal product and a 60 kDa carboxy-terminal protein. The N-terminal protein was further processed into 84, 76 and 73 kDa products. Clustering analysis resolved PmpD proteins into three distinct clades with C. abortus Pmp18D, being most similar to those originating from C. psittaci, C. felis and C. caviae.This study indicates that C. abortus Pmp18D is proteolytically processed at the cell surface similar to the proteins of C. trachomatis and C. pneumoniae. However, patterns of cleavage are species-specific, with low sequence conservation of PmpD across the genus. The absence of conserved domains indicates that the function of the PmpD molecule in chlamydia remains to be elucidated.

Processing of Chlamydia abortus polymorphic membrane protein 18D during the chlamydial developmental cycle.

Science.gov (United States)

Wheelhouse, Nick M; Sait, Michelle; Aitchison, Kevin; Livingstone, Morag; Wright, Frank; McLean, Kevin; Inglis, Neil F; Smith, David G E; Longbottom, David

2012-01-01

Chlamydia possess a unique family of autotransporter proteins known as the Polymorphic membrane proteins (Pmps). While the total number of pmp genes varies between Chlamydia species, all encode a single pmpD gene. In both Chlamydia trachomatis (C. trachomatis) and C. pneumoniae, the PmpD protein is proteolytically cleaved on the cell surface. The current study was carried out to determine the cleavage patterns of the PmpD protein in the animal pathogen C. abortus (termed Pmp18D). Using antibodies directed against different regions of Pmp18D, proteomic techniques revealed that the mature protein was cleaved on the cell surface, resulting in a100 kDa N-terminal product and a 60 kDa carboxy-terminal protein. The N-terminal protein was further processed into 84, 76 and 73 kDa products. Clustering analysis resolved PmpD proteins into three distinct clades with C. abortus Pmp18D, being most similar to those originating from C. psittaci, C. felis and C. caviae. This study indicates that C. abortus Pmp18D is proteolytically processed at the cell surface similar to the proteins of C. trachomatis and C. pneumoniae. However, patterns of cleavage are species-specific, with low sequence conservation of PmpD across the genus. The absence of conserved domains indicates that the function of the PmpD molecule in chlamydia remains to be elucidated.

Detection of Chlamydia pneumoniae in Ankylosing Spondylitis Patients

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Dunya Fareed Salloom

2018-03-01

Full Text Available Ankylosing spondylitis is a complex debilitating disease because its pathogenesis is not clear. This study aims at detecting some pathogenesis factors that lead to induce the disease. Chlamydia pneumoniae is one of these pathogenesis factors which acts as a triggering factor for the disease. The study groups included forty Iraqi Ankylosing spondylitis patients and forty healthy persons as a control group. Immunological and molecular examinations were done to detect Chlamydia. pneumoniae in AS group. The immunological results were performed by Enzyme-Linked Immunosorbent Assay (ELISA to detect anti-IgG and anti-IgM antibodies of C. pneumoniae revealed that five of forty AS patients' samples (12.5% were positive for anti-IgG and IgM C. pneumoniae antibodies compared to controls which revealed seronegative. Molecular detection included 16srRNA and HSP-70 genes were to ensure the serological examination for detection of bacteria in the five blood samples which were positive; therefore, these results improved that C. pneumoniae played a role in the pathogenesis of the disease.

Glutathione provides a source of cysteine essential for intracellular multiplication of Francisella tularensis.

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Khaled Alkhuder

2009-01-01

Full Text Available Francisella tularensis is a highly infectious bacterium causing the zoonotic disease tularemia. Its ability to multiply and survive in macrophages is critical for its virulence. By screening a bank of HimarFT transposon mutants of the F. tularensis live vaccine strain (LVS to isolate intracellular growth-deficient mutants, we selected one mutant in a gene encoding a putative gamma-glutamyl transpeptidase (GGT. This gene (FTL_0766 was hence designated ggt. The mutant strain showed impaired intracellular multiplication and was strongly attenuated for virulence in mice. Here we present evidence that the GGT activity of F. tularensis allows utilization of glutathione (GSH, gamma-glutamyl-cysteinyl-glycine and gamma-glutamyl-cysteine dipeptide as cysteine sources to ensure intracellular growth. This is the first demonstration of the essential role of a nutrient acquisition system in the intracellular multiplication of F. tularensis. GSH is the most abundant source of cysteine in the host cytosol. Thus, the capacity this intracellular bacterial pathogen has evolved to utilize the available GSH, as a source of cysteine in the host cytosol, constitutes a paradigm of bacteria-host adaptation.

Surveillance for Intracellular Antibody by Cytosolic Fc Receptor TRIM21

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William A. McEwan

2016-11-01

Full Text Available TRIM21 has emerged as an atypical Fc receptor that is broadly conserved and widely expressed in the cytoplasm of mammalian cells. Viruses that traffic surface-bound antibodies into the cell during infection recruit TRIM21 via a high affinity interaction between Fc and TRIM21 PRYSPRY domain. Following binding of intracellular antibody, TRIM21 acts as both antiviral effector and sensor for innate immune signalling. These activities serve to reduce viral replication by orders of magnitude in vitro and contribute to host survival during in vivo infection. Neutralization occurs rapidly after detection and requires the activity of the ubiquitin-proteasome system. The microbial targets of this arm of intracellular immunity are still being identified: TRIM21 activity has been reported following infection by several non-enveloped viruses and intracellular bacteria. These findings extend the sphere of influence of antibodies to the intracellular domain and have broad implications for immunity. TRIM21 has been implicated in the chronic auto-immune condition systemic lupus erythematosus and is itself an auto-antigen in Sjögren’s syndrome. This review summarises our current understanding of TRIM21’s role as a cytosolic Fc receptor and briefly discusses pathological circumstances where intracellular antibodies have been described, or are hypothesized to occur, and may benefit from further investigations of the role of TRIM21.

Atherogenic effects of Chlamydia pneumoniae: refuting the innocent bystander hypothesis.

NARCIS (Netherlands)

Selzman, C.H.; Netea, M.G.; Zimmerman, M.A.; Weinberg, A.; Reznikov, L.L.; Grover, F.L.; Dinarello, C.A.

2003-01-01

OBJECTIVE: Serologic evidence of Chlamydia pneumoniae infection and atherosclerosis was first demonstrated in patients with ischemic heart disease in 1988. Subsequently, the organism has been detected in several cardiovascular lesions. Outside of observational reports, few studies mechanistically

'It Opened My Eyes'-examining the impact of a multifaceted chlamydia testing intervention on general practitioners using Normalization Process Theory.

Science.gov (United States)

Yeung, Anna; Hocking, Jane; Guy, Rebecca; Fairley, Christopher K; Smith, Kirsty; Vaisey, Alaina; Donovan, Basil; Imrie, John; Gunn, Jane; Temple-Smith, Meredith

2018-03-28

Chlamydia is the most common notifiable sexually transmissible infection in Australia. Left untreated, it can develop into pelvic inflammatory disease and infertility. The majority of notifications come from general practice and it is ideally situated to test young Australians. The Australian Chlamydia Control Effectiveness Pilot (ACCEPt) was a multifaceted intervention that aimed to reduce chlamydia prevalence by increasing testing in 16- to 29-year-olds attending general practice. GPs were interviewed to describe the effectiveness of the ACCEPt intervention in integrating chlamydia testing into routine practice using Normalization Process Theory (NPT). GPs were purposively selected based on age, gender, geographic location and size of practice at baseline and midpoint. Interview data were analysed regarding the intervention components and results were interpreted using NPT. A total of 44 GPs at baseline and 24 at midpoint were interviewed. Most GPs reported offering a test based on age at midpoint versus offering a test based on symptoms or patient request at baseline. Quarterly feedback was the most significant ACCEPt component for facilitating a chlamydia test. The ACCEPt intervention has been able to moderately normalize chlamydia testing among GPs, although the components had varying levels of effectiveness. NPT can demonstrate the effective implementation of an intervention in general practice and has been valuable in understanding which components are essential and which components can be improved upon.

CHLAMYFAST-OIA TEST IN THE GENITAL CHLAMYDIA MALE INFECTION DIAGNOSIS

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Anka Vasic

2004-07-01

Full Text Available The genital infections caused by Chlamydia trachomatis (Ch. trachomatis, Mycoplasma hominis (M. hominis and Ureaplasma urealyticum (U. urealyticum represent, in the countries with developed industry, those diseases which are most often sexually transmissible. Chronic infections provoked by the mentioned causes are considered to be the risk factors for sterility.The aim of this paper is to examine the importance and specific characteristics of the CHLAMYFAST-OIA test in the Chlamydia genital infection diagnosis. This study includes 400 male patients with urethritis symptoms. The CHLAMYFAST-optical immunologic test has been used to determine the presence of the Ch. trachomatis in the genital tract of 360 males (Mycoplasma, International, France. The genital microplasmas, that is M. hominis and U. urealyticum, have been detected with the use of MYCOFAST-test (Mycroplasm International, France. The presence of the genital microplasmas has been studied in 129 patients.Chlamydia genital infection has been determined in 128 males (35,55%. The genital infection caused by M. hominis has been determined in a largely lower number of patients (3; 2,32%, as well as the infection caused by U. urealyticum (in 8 patients; 6,20%. Mixed infections have been detected in 8 patients. In 6 men (4,64% there has been detected a mixed infection caused by genital microplasmas. The mixed infection provoked by Ch. Trachomatis and M. hominis, and the one caused by Ch. trachomatis and U. urealyticum, has been proven only in one patient respectively.

An α-helical core encodes the dual functions of the chlamydial protein IncA.

Science.gov (United States)

Ronzone, Erik; Wesolowski, Jordan; Bauler, Laura D; Bhardwaj, Anshul; Hackstadt, Ted; Paumet, Fabienne

2014-11-28

Chlamydia is an intracellular bacterium that establishes residence within parasitophorous compartments (inclusions) inside host cells. Chlamydial inclusions are uncoupled from the endolysosomal pathway and undergo fusion with cellular organelles and with each other. To do so, Chlamydia expresses proteins on the surface of the inclusion using a Type III secretion system. These proteins, termed Incs, are located at the interface between host and pathogen and carry out the functions necessary for Chlamydia survival. Among these Incs, IncA plays a critical role in both protecting the inclusion from lysosomal fusion and inducing the homotypic fusion of inclusions. Within IncA are two regions homologous to eukaryotic SNARE (soluble N-ethylmaleimide-sensitive factor attachment receptor) domains referred to as SNARE-like domain 1 (SLD1) and SNARE-like domain 2 (SLD2). Using a multidisciplinary approach, we have discovered the functional core of IncA that retains the ability to both inhibit SNARE-mediated fusion and promote the homotypic fusion of Chlamydia inclusions. Circular dichroism and analytical ultracentrifugation experiments show that this core region is composed almost entirely of α-helices and assembles into stable homodimers in solution. Altogether, we propose that both IncA functions are encoded in a structured core domain that encompasses SLD1 and part of SLD2. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

An enhanced functional interrogation/manipulation of intracellular signaling pathways with the peptide 'stapling' technology.

Science.gov (United States)

He, Y; Chen, D; Zheng, W

2015-11-12

Specific protein-protein interactions (PPIs) constitute a key underlying mechanism for the presence of a multitude of intracellular signaling pathways, which are essential for the survival of normal and cancer cells. Specific molecular blockers for a crucial PPI would therefore be invaluable tools for an enhanced functional interrogation of the signaling pathway harboring this particular PPI. On the other hand, if a particular PPI is essential for the survival of cancer cells but is absent in or dispensable for the survival of normal cells, its specific molecular blockers could potentially be developed into effective anticancer therapeutics. Due to the flat and extended PPI interface, it would be conceivably difficult for small molecules to achieve an effective blockade, a problem which could be potentially circumvented with peptides or proteins. However, the well-documented proteolytic instability and cellular impermeability of peptides and proteins in general would make their developing into effective intracellular PPI blockers quite a challenge. With the advent of the peptide 'stapling' technology which was demonstrated to be able to stabilize the α-helical conformation of a peptide via bridging two neighboring amino-acid side chains with a 'molecular staple', a linear parent peptide could be transformed into a stronger PPI blocker with enhanced proteolytic stability and cellular permeability. This review will furnish an account on the peptide 'stapling' technology and its exploitation in efforts to achieve an enhanced functional interrogation or manipulation of intracellular signaling pathways especially those that are cancer relevant.

Porphyromonas gingivalis evasion of autophagy and intracellular killing by human myeloid dendritic cells involves DC-SIGN-TLR2 crosstalk.

Science.gov (United States)

El-Awady, Ahmed R; Miles, Brodie; Scisci, Elizabeth; Kurago, Zoya B; Palani, Chithra D; Arce, Roger M; Waller, Jennifer L; Genco, Caroline A; Slocum, Connie; Manning, Matthew; Schoenlein, Patricia V; Cutler, Christopher W

2015-02-01

Signaling via pattern recognition receptors (PRRs) expressed on professional antigen presenting cells, such as dendritic cells (DCs), is crucial to the fate of engulfed microbes. Among the many PRRs expressed by DCs are Toll-like receptors (TLRs) and C-type lectins such as DC-SIGN. DC-SIGN is targeted by several major human pathogens for immune-evasion, although its role in intracellular routing of pathogens to autophagosomes is poorly understood. Here we examined the role of DC-SIGN and TLRs in evasion of autophagy and survival of Porphyromonas gingivalis in human monocyte-derived DCs (MoDCs). We employed a panel of P. gingivalis isogenic fimbriae deficient strains with defined defects in Mfa-1 fimbriae, a DC-SIGN ligand, and FimA fimbriae, a TLR2 agonist. Our results show that DC-SIGN dependent uptake of Mfa1+P. gingivalis strains by MoDCs resulted in lower intracellular killing and higher intracellular content of P. gingivalis. Moreover, Mfa1+P. gingivalis was mostly contained within single membrane vesicles, where it survived intracellularly. Survival was decreased by activation of TLR2 and/or autophagy. Mfa1+P. gingivalis strain did not induce significant levels of Rab5, LC3-II, and LAMP1. In contrast, P. gingivalis uptake through a DC-SIGN independent manner was associated with early endosomal routing through Rab5, increased LC3-II and LAMP-1, as well as the formation of double membrane intracellular phagophores, a characteristic feature of autophagy. These results suggest that selective engagement of DC-SIGN by Mfa-1+P. gingivalis promotes evasion of antibacterial autophagy and lysosome fusion, resulting in intracellular persistence in myeloid DCs; however TLR2 activation can overcome autophagy evasion and pathogen persistence in DCs.

EXPERIENCE OF DESOXIRIBONUCLEATE SODIUM IMMUNOMODULATOR APPLICATION IN TREATMENT FOR REACTIVE ARTHRITIS OF CHLAMYDIA AETIOLOGY AMONG CHILDREN

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L.A. Balykova

2007-01-01

Full Text Available Researchers compared efficacy of the conventional therapy (oilment with non steriod anti-inflammatory medication, diclofena sodium and azithromycin among children with reactive arthritis of Chlamydia etiology and treatment with introduction of gluccosaminilmuramildi peptide and desoxiribonucleate sodium immunomodulators. The article shows that application of immunomodulators in combination with the conventional therapy provided for the decrease of the articular syndrome intensity, reduced the need of the patients in local corticosteroids and conduced to the reduction of the lab process activity indices. Further more, they noticed reduced recurrence of the antibodies to Chlamydias and their titers in the blood serum, while general intensity of the antiinflammatory effects from the combined therapy, which included glucosaminilmuramildipeptide and desoxiribonucleate sodium immunomodulators along with the antibiotic, proved to be comparable.Key words: children, reactive arthritis, chlamydia infection, immunomodulators.

Intracellular activity of the peptide antibiotic NZ2114: studies with Staphylococcus aureus and human THP-1 monocytes, and comparison with daptomycin and vancomycin

DEFF Research Database (Denmark)

Brinch, Karoline Sidelmann; Tulkens, Paul M; Van Bambeke, Francoise

2010-01-01

Staphylococcus aureus survives inside eukaryotic cells. Our objective was to assess the activity of NZ2114, a novel peptidic antibiotic, against intracellular S. aureus in comparison with established antistaphylococcal agents acting on the bacterial envelope with a distinct mechanism.......Staphylococcus aureus survives inside eukaryotic cells. Our objective was to assess the activity of NZ2114, a novel peptidic antibiotic, against intracellular S. aureus in comparison with established antistaphylococcal agents acting on the bacterial envelope with a distinct mechanism....

Risk factors associated with Chlamydia and gonorrhea infection among female sex workers in two Mexico-U.S. border cities

Science.gov (United States)

Loza, Oralia; Strathdee, Steffanie A.; Martinez, Gustavo A.; Lozada, Remedios; Ojeda, Victoria D.; Staines-Orozco, Hugo; Patterson, Thomas L.

2011-01-01

Female sex workers (FSWs) aged ≥18 years without known HIV infection living in Tijuana and Ciudad Juarez who had recent unprotected sex with clients underwent interviews and testing for Chlamydia and gonorrhea using nucleic acid amplification. Correlates of each infection were identified with logistic regression. Among 798 FSWs, prevalence of Chlamydia and gonorrhea was 13.0% and 6.4%. Factors independently associated with Chlamydia were being younger, working in Tijuana versus Ciudad Juarez, and recent methamphetamine injection. Factors independently associated with gonorrhea were working in Tijuana versus Ciudad Juarez, using illegal drugs before or during sex, and having a recent male partner who injects drugs. Chlamydia and gonorrhea infection were more closely associated with FSWs’ drug use behaviors and that of their sexual partners than with sexual behaviors. Prevention should focus on subgroups of FSWs and their partners who use methamphetamine and who inject drugs. PMID:20852194

Molecular detection of Chlamydia Trachomatis and Mycoplasma Hominis in endometriosis lesions

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F. Azizvakili

2016-12-01

Full Text Available Background: Retrograde of menstrual blood into the peritoneal cavity is one of the accepted theories for initiation of endometriosis although indicated that other factors are involved in pathogenesis. Investigation of infectious agents is important in this regard. Objective: To investigate the presence of bacterial infections; Chlamydia trachomatis and Mycoplasma Hominis as risk factors in endometriosis lesions. Methods: This case-control study was conducted in Sarem Hospital in 2014. DNA was extracted from 90 paraffin-embedded blocks included 40 endometriosis tissue samples, 23 samples of endometrial tissue from the same patients and 27 samples of endometrial tissue of the patients without endometriosis, and molecular analysis were performed using polymerase chain reaction. Results were analyzed by Fisher Exact Test and McNemar Test. Findings: Chlamydia trachomatis infection was seen in 11 (27.5% endometriosis tissue, 3 (13% normal tissue from patients and 10 (37% in patient without endometriosis. Mycoplasma hominis was diagnosed in 11 (27.5% endometriosis tissue, 7 (30.4% of normal tissue from patients and one patient without endometriosis (3.7%. These differences show significant relations between infection with Mycoplasma hominis and endometriosis. Conclusion: The findings of this study did not show significant association between Chlamydia trachomatis infections and endometriosis. However; it seems Mycoplasma hominis infection can increase the risk of endometriosis incidence.

Chlamydia and Male Lower Urinary Tract Diseases

OpenAIRE

Lee, Young-Suk; Lee, Kyu-Sung

2013-01-01

Of the chlamydia species that can cause infections in humans, C. trachomatis is responsible for lower urinary tract diseases in men and women. C. trachomatis infections are prevalent worldwide, but current research is focused on females, with the burden of disease and infertility sequelae considered to be a predominantly female problem. However, a role for this pathogen in the development of male urethritis, epididymitis, and orchitis is widely accepted. Also, it can cause complications such ...

Use of polymerase chain reaction for detection of Chlamydia trachomatis

DEFF Research Database (Denmark)

Østergaard, Lars; Birkelund, Svend; Christiansen, Gunna

1990-01-01

A polymerase chain reaction (PCR) assay was developed for detection of Chlamydia trachomatis DNA. From the published sequence of the common C. trachomatis plasmid, two primer sets were selected. Detection of amplified sequences was done by agarose gel electrophoresis of cleaved or uncleaved...

Identifying Relationships between High-Risk Sexual Behaviors and Screening Positive for Chlamydia and Gonorrhea in School-Wide Screening Events

Science.gov (United States)

Salerno, Jennifer; Darling-Fisher, Cindy; Hawkins, Nicole M.; Fraker, Elizabeth

2013-01-01

Background: This article describes a school-wide sexually transmitted infection (STI) screening to identify adolescent high-risk sexual behaviors, STI history/incidence, and presence of chlamydia and gonorrhea, and examines relationships between high-risk behaviors and screening positive for chlamydia and gonorrhea in an alternative high school…

Pathogenic mechanisms of intracellular bacteria.

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Niller, Hans Helmut; Masa, Roland; Venkei, Annamária; Mészáros, Sándor; Minarovits, Janos

2017-06-01

We wished to overview recent data on a subset of epigenetic changes elicited by intracellular bacteria in human cells. Reprogramming the gene expression pattern of various host cells may facilitate bacterial growth, survival, and spread. DNA-(cytosine C5)-methyltransferases of Mycoplasma hyorhinis targeting cytosine-phosphate-guanine (CpG) dinucleotides and a Mycobacterium tuberculosis methyltransferase targeting non-CpG sites methylated the host cell DNA and altered the pattern of gene expression. Gene silencing by CpG methylation and histone deacetylation, mediated by cellular enzymes, also occurred in M. tuberculosis-infected macrophages. M. tuberculosis elicited cell type-specific epigenetic changes: it caused increased DNA methylation in macrophages, but induced demethylation, deposition of euchromatic histone marks and activation of immune-related genes in dendritic cells. A secreted transposase of Acinetobacter baumannii silenced a cellular gene, whereas Mycobacterium leprae altered the epigenotype, phenotype, and fate of infected Schwann cells. The 'keystone pathogen' oral bacterium Porphyromonas gingivalis induced local DNA methylation and increased the level of histone acetylation in host cells. These epigenetic changes at the biofilm-gingiva interface may contribute to the development of periodontitis. Epigenetic regulators produced by intracellular bacteria alter the epigenotype and gene expression pattern of host cells and play an important role in pathogenesis.

Delivery of rifampicin-chitin nanoparticles into the intracellular compartment of polymorphonuclear leukocytes.

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Smitha, K T; Nisha, N; Maya, S; Biswas, Raja; Jayakumar, R

2015-03-01

Polymorphonuclear leukocytes (PMNs) provide the primary host defence against invading pathogens by producing reactive oxygen species (ROS) and microbicidal products. However, few pathogens can survive for a prolonged period of time within the PMNs. Additionally their intracellular lifestyle within the PMNs protect themselves from the additional lethal action of host immune systems such as antibodies and complements. Antibiotic delivery into the intracellular compartments of PMNs is a major challenge in the field of infectious diseases. In order to deliver antibiotics within the PMNs and for the better treatment of intracellular bacterial infections we synthesized rifampicin (RIF) loaded amorphous chitin nanoparticles (RIF-ACNPs) of 350±50 nm in diameter. RIF-ACNPs nanoparticles are found to be non-hemolytic and non-toxic against a variety of host cells. The release of rifampicin from the prepared nanoparticles was ∼60% in 24 h, followed by a sustained pattern till 72 h. The RIF-ACNPs nanoparticles showed 5-6 fold enhanced delivery of RIF into the intracellular compartments of PMNs. The RIF-ACNPs showed anti-microbial activity against Escherichia coli, Staphylococcus aureus and a variety of other bacteria. In summary, our results suggest that RIF-ACNPs could be used to treat a variety of intracellular bacterial infections. Copyright © 2014 Elsevier B.V. All rights reserved.

A method for functional trans-complementation of intracellular Francisella tularensis.

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Shaun Steele

Full Text Available Francisella tularensis is a highly infectious bacterial pathogen that invades and replicates within numerous host cell types. After uptake, F. tularensis bacteria escape the phagosome, replicate within the cytosol, and suppress cytokine responses. However, the mechanisms employed by F. tularensis to thrive within host cells are mostly unknown. Potential F. tularensis mutants involved in host-pathogen interactions are typically discovered by negative selection screens for intracellular replication or virulence. Mutants that fulfill these criteria fall into two categories: mutants with intrinsic intracellular growth defects and mutants that fail to modify detrimental host cell processes. It is often difficult and time consuming to discriminate between these two possibilities. We devised a method to functionally trans-complement and thus identify mutants that fail to modify the host response. In this assay, host cells are consistently and reproducibly infected with two different F. tularensis strains by physically tethering the bacteria to antibody-coated beads. To examine the efficacy of this protocol, we tested phagosomal escape, cytokine suppression, and intracellular replication for F. tularensis ΔripA and ΔpdpC. ΔripA has an intracellular growth defect that is likely due to an intrinsic defect and fails to suppress IL-1β secretion. In the co-infection model, ΔripA was unable to replicate in the host cell when wild-type bacteria infected the same cell, but cytokine suppression was rescued. Therefore, ΔripA intracellular growth is due to an intrinsic bacterial defect while cytokine secretion results from a failed host-pathogen interaction. Likewise, ΔpdpC is deficient for phagosomal escape, intracellular survival and suppression of IL-1β secretion. Wild-type bacteria that entered through the same phagosome as ΔpdpC rescued all of these phenotypes, indicating that ΔpdpC failed to properly manipulate the host. In summary, functional

In vitro activity of a partially purified and characterized bark extract of Castanea sativa Mill. (ENC®) against Chlamydia spp.

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Papa, Valentina; Ginocchietti, Laura; Budriesi, Roberta; Micucci, Matteo; Costa, Roberta; Biondi, Roberta; Cevenini, Roberto; Chiarini, Alberto; Aldini, Rita; Donati, Manuela; Pollini, Gian Matteo; Cenacchi, Giovanna

2017-01-01

Castanea sativa Mill (ENC®), containing tannins against 33 Chlamydia strains, was compared to SMAP-29 with inhibitory effect against C. trachomatis and C. pneumoniae. The ENC® activity against Chlamydia spp. was evaluated determining the lowest concentration to achieve more than half reduction of intact chlamydial inclusions versus controls. ENC® reduced all Chlamydia strains tested at 1 µg/mL, while SMAP-29 induced reductions of C. trachomatis and C. pneumoniae infectivity at 10 µg/mL. A great reduction of C. trachomatis, C. pneumoniae, and C. abortus infectivity was achieved with a 10 µg/mL ENC® concentration, whereas their infectivity was almost inhibited at 100 µg/mL ENC® concentration.

Analysis of Humoral Immune Responses to Surface and Virulence-Associated Chlamydia abortus Proteins in Ovine and Human Abortions by Use of a Newly Developed Line Immunoassay.

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Hagemann, Jürgen Benjamin; Simnacher, Ulrike; Longbottom, David; Livingstone, Morag; Maile, Julia; Soutschek, Erwin; Walder, Gernot; Boden, Katharina; Sachse, Konrad; Essig, Andreas

2016-07-01

The obligate intracellular bacterium Chlamydia abortus is the causative agent of enzootic abortion of ewes and poses a significant zoonotic risk for pregnant women. Using proteomic analysis and gene expression library screening in a previous project, we identified potential virulence factors and candidates for serodiagnosis, of which nine were scrutinized here with a strip immunoassay. We have shown that aborting sheep exhibited a strong antibody response to surface (MOMP, MIP, Pmp13G) and virulence-associated (CPAF, TARP, SINC) antigens. While the latter disappeared within 18 weeks following abortion in a majority of the animals, antibodies to surface proteins persisted beyond the duration of the study. In contrast, nonaborting experimentally infected sheep developed mainly antibodies to surface antigens (MOMP, MIP, Pmp13G), all of which did not persist. We were also able to detect antibodies to these surface antigens in C abortus-infected women who had undergone septic abortion, whereas a group of shepherds and veterinarians with occupational exposure to C abortus-infected sheep revealed only sporadic immune responses to the antigens selected. The most specific antigen for the serodiagnosis of human C abortus infections was Pmp13G, which showed no cross-reactivity with other chlamydiae infecting humans. We suggest that Pmp13G-based serodiagnosis accomplished by the detection of antibodies to virulence-associated antigens such as CPAF, TARP, and SINC may improve the laboratory diagnosis of human and animal C abortus infections. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Early sexual behaviour and Chlamydia trachomatis infection – a population based cross-sectional study on gender differences among adolescents in Norway

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Gravningen Kirsten

2012-11-01

Full Text Available Abstract Background Early sexual behaviour has been shown to differ significantly between genders, but few studies have addressed this topic to explain the commonly observed differences in chlamydia rates between adolescent girls and boys. Our study aimed to determine chlamydia prevalence in adolescents aged 15–20 years in a high-incidence area in Norway, and to identify gender-specific early sexual behaviours associated with infection. Methods A population based cross-sectional study was conducted among all high school students in five towns in Finnmark county in 2009, using a web-based questionnaire and real-time Chlamydia trachomatis PCR in first-void urine samples (participation rate 85%, 800 girls/818 boys, mean age 17.2 years. Crude and multivariable logistic regression models were applied with chlamydia test result as dependent variable. Results Prevalence of chlamydia infection was 5.7% (95% confidence interval, CI, 4.4–7.3%. Girls were twice as likely to be infected as boys (7.3%, 5.3–9.7 vs 3.9%, 2.3–6.0. Girls reported earlier sexual debut, older partners, higher lifetime number of partners, and were poorer condom users. In girls, higher maternal education (odds ratio, OR, 2.2, 95% CI 1.1–4.4, ≥2 sexual partners past 6 months (OR 3.6, 1.8–7.3, and partner meeting venue at a private party, bar or disco (OR 5.0, 1.1–22.7 increased the odds of infection in the multivariable model. In boys, condom use at first intercourse (OR 0.06, 0.01–0.42 decreased the odds of infection, while having an older last sexual partner (OR 3.7, 1.3–11.0 increased the odds. In all participants, the risk of infection increased if residence outside the family home during school year (OR 2.0, 1.2–3.6, and decreased if condom was used at last intercourse (OR 0.2, 0.1–0.8. Conclusions We detected significant gender differences in chlamydia prevalence and sexual behaviours, and accordingly differing independent risk factors for chlamydia

Identification of Phylogenetic Position in the Chlamydiaceae Family for Chlamydia Strains Released from Monkeys and Humans with Chlamydial Pathology

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Alexander Karaulov

2010-01-01

Full Text Available Based on the results of the comparative analysis concerning relatedness and evolutional difference of the 16S–23S nucleotide sequences of the middle ribosomal cluster and 23S rRNA I domain, and based on identification of phylogenetic position for Chlamydophila pneumoniae and Chlamydia trichomatis strains released from monkeys, relatedness of the above stated isolates with similar strains released from humans and with strains having nucleotide sequences presented in the GenBank electronic database has been detected for the first time ever. Position of these isolates in the Chlamydiaceae family phylogenetic tree has been identified. The evolutional position of the investigated original Chlamydia and Chlamydophila strains close to analogous strains from the Gen-Bank electronic database has been demonstrated. Differences in the 16S–23S nucleotide sequence of the middle ribosomal cluster and 23S rRNA I domain of plasmid and nonplasmid Chlamydia trachomatis strains released from humans and monkeys relative to different genotype groups (group B-B, Ba, D, Da, E, L1, L2, L2a; intermediate group-F, G, Ga have been revealed for the first time ever. Abnormality in incA chromosomal gene expression resulting in Chlamydia life development cycle disorder, and decrease of Chlamydia virulence can be related to probable changes in the nucleotide sequence of the gene under consideration

Inorganic Polyphosphate Is Essential for Salmonella Typhimurium Virulence and Survival in Dictyostelium discoideum

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Macarena A. Varas

2018-01-01

Full Text Available Inorganic polyphosphate (polyP deficiency in enteric bacterial pathogens reduces their ability to invade and establish systemic infections in different hosts. For instance, inactivation of the polyP kinase gene (ppk encoding the enzyme responsible for polyP biosynthesis reduces invasiveness and intracellular survival of Salmonella enterica serovar Typhimurium (S. Typhimurium in epithelial cells and macrophages in vitro. In addition, the virulence in vivo of a S. Typhimurium Δppk mutant is significantly reduced in a murine infection model. In spite of these observations, the role played by polyP during the Salmonella-host interaction is not well understood. The social amoeba Dictyostelium discoideum has proven to be a useful model for studying relevant aspects of the host-pathogen interaction. In fact, many intracellular pathogens can survive within D. discoideum cells using molecular mechanisms also required to survive within macrophages. Recently, we established that S. Typhimurium is able to survive intracellularly in D. discoideum and identified relevant genes linked to virulence that are crucial for this process. The aim of this study was to determine the effect of a polyP deficiency in S. Typhimurium during its interaction with D. discoideum. To do this, we evaluated the intracellular survival of wild-type and Δppk strains of S. Typhimurium in D. discoideum and the ability of these strains to delay the social development of the amoeba. In contrast to the wild-type strain, the Δppk mutant was unable to survive intracellularly in D. discoideum and enabled the social development of the amoeba. Both phenotypes were complemented using a plasmid carrying a copy of the ppk gene. Next, we simultaneously evaluated the proteomic response of both S. Typhimurium and D. discoideum during host-pathogen interaction via global proteomic profiling. The analysis of our results allowed the identification of novel molecular signatures that give insight into

"The rate of Chlamydia Trachomatis, Mycoplasma Hominis and Ureaplasma Urealyticum in females with habitual abortion and its comparison with control group "

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Salari MH

2002-06-01

Full Text Available Females abortion is one of the most important sequela of genital infection with chlamydia trachomatis, Mycoplasma hominis and Ureaplasma urealyticum.In this study frequency of Chlamydia trachomatis, Mycoplasma hominis and Ureaplasma urealyticum was studied in 125 females with habitual abortion by direct and indirect immunofluorescence tests and culture method and compared with 250 normal population. The results obtained were as follow: Mycoplasma hominis was isolated from 18 (14.4% females with habitual abortion and 18 (7.2% normal population (P=0.0139. Ureaplasma urealyticum was isolated from 39(31.2% females with habitual aboration and 48 (19.2% normal population (P=0.0045. Chlamydia trachomatis was detected by direct immunofluorescence test in 9 (7.2% of cases and 2 (0.8% of control groups (P=0.0002. the antibody titer against D-K serotypes of Chlamydia trachomatis was also measured. The valuable titer of antibody (>1/16 was detected in 15 (12% of cases and 8 (3.2% of control groups (P=0.0004.The results show that chlamydia trachomatis and Ureaplasma urealyticum may be responsible for some cases of abortion.

Comparison of subcutaneous versus intranasal immunization of male koalas (Phascolarctos cinereus) for induction of mucosal and systemic immunity against Chlamydia pecorum.

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Waugh, Courtney A; Timms, Peter; Andrew, Dean; Rawlinson, Galit; Brumm, Jacqui; Nilsson, Karen; Beagley, Kenneth W

2015-02-11

Chlamydia pecorum infections are debilitating in the koala, contributing significantly to morbidity and mortality, with current antibiotic treatments having minimal success and adversely affecting gut microflora. This, combined with the sometimes-asymptomatic nature of the infection, suggests that an efficacious anti-chlamydial vaccine is required to control chlamydial infections in the koala. To date vaccination studies have focused primarily on female koalas, however, given the physiological differences between male and female reproductive tracts, we tested the efficacy of a vaccine in 12 captive male koalas. We evaluated the potential of both subcutaneous and intranasal vaccine delivery to elicit mucosal immunity in male koalas. Our results showed that both intranasal and subcutaneous delivery of a vaccine consisting of C. pecorum major outer membrane protein (MOMP) and the adjuvant immunostimulating complex (ISC) induced significant immune responses in male koalas. Subcutaneous immunization elicited stronger cell-mediated responses in peripheral blood lymphocytes (PBL), and greater plasma antibody levels whereas the intranasal immunization elicited stronger humoral responses in urogenital tract (UGT) secretions. This is the first time a Chlamydia vaccine has been tested in the male koala and the first assessment of a mucosal vaccination route in this species. Our results suggest that vaccination of male koalas can elicit mucosal immunity and could contribute to the long-term survivability of wild populations of the koala. Copyright © 2014 Elsevier Ltd. All rights reserved.

Large-scale testing of women in Copenhagen has not reduced the prevalence of Chlamydia trachomatis infections

DEFF Research Database (Denmark)

Westh, Henrik Torkil; Kolmos, H J

2003-01-01

OBJECTIVE: To examine the impact of a stable, large-scale enzyme immunoassay (EIA) Chlamydia trachomatis testing situation in Copenhagen, and to estimate the impact of introducing a genomic-based assay with higher sensitivity and specificity. METHODS: Over a five-year study period, 25 305-28 505...... and negative predictive values of the Chlamydia test result, new screening strategies for both men and women in younger age groups will be necessary if chlamydial infections are to be curtailed....

The contribution of Chlamydia-specific CD8⁺ T cells to upper genital tract pathology.

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Vlcek, Kelly R; Li, Weidang; Manam, Srikanth; Zanotti, Brian; Nicholson, Bruce J; Ramsey, Kyle H; Murthy, Ashlesh K

2016-02-01

Genital chlamydial infections lead to severe upper reproductive tract pathology in a subset of untreated women. We demonstrated previously that tumor necrosis factor (TNF)-α-producing CD8(+) T cells contribute significantly to chlamydial upper genital tract pathology in female mice. In addition, we observed that minimal chlamydial oviduct pathology develops in OT-1 transgenic (OT-1) mice, wherein the CD8(+) T-cell repertoire is restricted to recognition of the ovalbumin peptide Ova(257-264), suggesting that non-Chlamydia-specific CD8(+) T cells may not be responsible for chlamydial pathogenesis. In the current study, we evaluated whether antigen-specific CD8(+) T cells mediate chlamydial pathology. Groups of wild-type (WT) C57BL/6J, OT-1 mice, and OT-1 mice replete with WT CD8(+) T cells (1 × 10(6) cells per mouse intravenously) were infected intravaginally with C. muridarum (5 × 10(4) IFU/mouse). Serum total anti-Chlamydia antibody and total splenic anti-Chlamydia interferon (IFN)-γ and TNF-α responses were comparable among the three groups of animals. However, Chlamydia-specific IFN-γ and TNF-α production from purified splenic CD8(+) T cells of OT-1 mice was minimal, whereas responses in OT-1 mice replete with WT CD8(+) T cells were comparable to those in WT animals. Vaginal chlamydial clearance was comparable between the three groups of mice. Importantly, the incidence and severity of oviduct and uterine horn pathology was significantly reduced in OT-1 mice but reverted to WT levels in OT-1 mice replete with WT CD8(+) T cells. Collectively, these results demonstrate that Chlamydia-specific CD8(+) T cells contribute significantly to upper genital tract pathology.

Chlamydia prevalence among women and men entering the National Job Training Program: United States, 2003-2007.

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Satterwhite, Catherine Lindsey; Tian, Lin H; Braxton, Jimmy; Weinstock, Hillard

2010-02-01

To analyze 5-year prevalence trends in Chlamydia trachomatis infections among high-risk young men and women aged 16 to 24 years entering the National Job Training Program, where universal screening is required. Entrance exams conducted in over 100 National Job Training Program centers from 2003 to 2007 were considered. Women provided cervical specimens tested using either a DNA hybridization probe (PACE 2, Gen-Probe, San Diego, CA) or a strand displacement amplification test (SDA, BD ProbeTec ET, Becton-Dickinson, Sparks, MD). In the absence of a pelvic exam, urine specimens were tested using SDA. PACE 2 testing was performed predominately from 2002 to 2005; from 2005 to 2007, SDA was used. All male testing was conducted using SDA on urine specimens. Chlamydia prevalence trends were assessed for women and men, using logistic regression models. Adjusted odds ratios (AOR), 95% confidence intervals (CI), and P-values were calculated. Approximately 15,000 women and 30,000 men were screened annually for chlamydia. Among both sexes, adjusted prevalence declined significantly from 2003 to 2007. In 2003, crude prevalence among women was 9.9%; in 2007, prevalence was 13.7%. However, after controlling for covariates, including increasingly sensitive tests, the model indicated a significant declining prevalence trend (AOR: 0.95, CI: 0.93-0.97, 4.6% decrease in odds per year). Among men, crude prevalence in 2003 was 8.4%; in 2007, prevalence was 8.3%; after controlling for possible confounding, a significant decline in prevalence was also detected (AOR: 0.98, CI: 0.96-0.99, 1.9% decrease in odds per year). In a relatively stable, high-risk population of young women and men, adjusted chlamydia prevalence declined from 2003 to 2007. Test technology plays a critical role in interpreting rates and should be considered whenever chlamydia rates are examined.

Effects of population based screening for Chlamydia infections in the Netherlands limited by declining participation rates.

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Boris V Schmid

Full Text Available BACKGROUND: A large trial to investigate the effectiveness of population based screening for chlamydia infections was conducted in the Netherlands in 2008-2012. The trial was register based and consisted of four rounds of screening of women and men in the age groups 16-29 years in three regions in the Netherlands. Data were collected on participation rates and positivity rates per round. A modeling study was conducted to project screening effects for various screening strategies into the future. METHODS AND FINDINGS: We used a stochastic network simulation model incorporating partnership formation and dissolution, aging and a sexual life course perspective. Trends in baseline rates of chlamydia testing and treatment were used to describe the epidemiological situation before the start of the screening program. Data on participation rates was used to describe screening uptake in rural and urban areas. Simulations were used to project the effectiveness of screening on chlamydia prevalence for a time period of 10 years. In addition, we tested alternative screening strategies, such as including only women, targeting different age groups, and biennial screening. Screening reduced prevalence by about 1% in the first two screening rounds and leveled off after that. Extrapolating observed participation rates into the future indicated very low participation in the long run. Alternative strategies only marginally changed the effectiveness of screening. Higher participation rates as originally foreseen in the program would have succeeded in reducing chlamydia prevalence to very low levels in the long run. CONCLUSIONS: Decreasing participation rates over time profoundly impact the effectiveness of population based screening for chlamydia infections. Using data from several consecutive rounds of screening in a simulation model enabled us to assess the future effectiveness of screening on prevalence. If participation rates cannot be kept at a sufficient level

Lactobacilli inactivate Chlamydia trachomatis through lactic acid but not H2O2.

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Zheng Gong

Full Text Available Lactobacillus species dominate the microbiome in the lower genital tract of most reproductive-age women. Producing lactic acid and H2O2, lactobacilli are believed to play an important role in prevention of colonization by and growth of pathogens. However, to date, there have been no reported studies characterizing how lactobacilli interact with Chlamydia trachomatis, a leading sexually transmitted bacterium. In this report, we demonstrate inactivation of C. trachomatis infectivity by culture media conditioned by Lactobacillus crispatus, L. gasseri and L. jensenii, known to be dominating organisms in the human vaginal microbiome. Lactobacillus still cultures produced lactic acid, leading to time- and concentration-dependent killing of C. trachomatis. Neutralization of the acidic media completely reversed chlamydia killing. Addition of lactic acid into Lactobacillus-unconditioned growth medium recapitulated the chlamydiacidal activity of conditioned media. The H2O2 concentrations in the still cultures were found to be comparable to those reported for the cervicovaginal fluid, but insufficient to inactivate chlamydiae. Aeration of Lactobacillus cultures by shaking markedly induced H2O2 production, but strongly inhibited Lactobacillus growth and lactic acid production, and thus severely affected acidification, leading to significantly reduced chlamydiacidal efficiency. These observations indicate lactobacilli inactivate chlamydiae primarily through maintaining acidity in a relatively hypoxic environment in the vaginal lumen with limited H2O2, which is consistent with the notion that women with higher vaginal pH are more prone to sexually transmitted C. trachomatis infection. In addition to lactic acid, formic acid and acetic acid also exhibited potent chlamydiacidal activities. Taken together, our findings imply that lowering the vaginal pH through engineering of the vaginal microbiome and other means will make women less susceptible to C

Overexpression and surface localization of the Chlamydia trachomatis major outer membrane protein in Escherichia coli

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Koehler, JF; Birkelund, Svend; Stephens, RS

1992-01-01

The Chlamydia trachomatis major outer membrane protein (MOMP) is the quantitatively predominant surface protein which has important functional, structural and antigenic properties. We have cloned and overexpressed the MOMP in Escherichia coli. The MOMP is surface exposed in C. trachomatis....... The induction of MOMP expression had a rapidly lethal effect on the L2rMOMP E. coli clone. Although no genetic system exists for Chlamydia, development of a stable, inducible E. coli clone which overexpresses the chlamydial MOMP permits a study of the biological properties of the MOMP, including...

'Show me the money': financial incentives increase chlamydia screening rates among tertiary students: a pilot study.

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Currie, Marian J; Schmidt, Matthias; Davis, Belinda K; Baynes, Anne M; O'Keefe, Elissa J; Bavinton, Tim P; McNiven, Michelle; Martin, Sarah J; Bowden, Francis J

2010-03-01

We hypothesise that text-messaging and financial incentives would increase tertiary student participation in chlamydia screening. A cross-sectional study was conducted over two phases on eight tertiary campuses during 2007. During Phase 1 (6 months) study activities were advertised through student organisations and media. Education and screening were offered during a range of student activities. During Phase 2 (4 days) education and screening were offered via text messages. Non-financial incentives were offered during Phase 1 and a $10 cash incentive was offered during Phase 2. Rates of specimens provided by students and the direct costs incurred during each phase were compared. 2786 students attended the 31 activities conducted in Phase 1. Of these, 627 students (22.5%) provided urine specimens for chlamydia testing. During Phase 2, the dissemination of 866 text messages resulted in urine specimens from 392 students (45.3%). Costs per test were AUD $175.11 in Phase 1 and AUD $27.13 in Phase 2. Compared with more labour intensive (and therefore more expensive) screening activities conducted over a 6-month period, offering a small financial incentive to tertiary students through text messaging over a 4-day period significantly increased participation in on-campus chlamydia screening. This model could readily be applied to other populations to increase participation in chlamydia screening.

Community-Based Assessment to Inform a Chlamydia Screening Program for Women in a Rural American Indian Community.

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Smartlowit-Briggs, Lucy; Pearson, Cynthia; Whitefoot, Patricia; Altamirano, Bianca N; Womack, Michelle; Bastin, Marie; Dombrowski, Julia C

2016-06-01

Rates of chlamydial infection in American Indian/Alaska Native women in the United States are approximately 4-fold those in non-Hispanic white women. We conducted a community-based survey of self-identified American Indian/Alaska Native women 14 to 25 years of age on a reservation in the Northwestern United States to inform a chlamydia screening strategy. The anonymous survey assessed respondents' knowledge, perceptions, and preferences related to chlamydia screening, results receipt, and partner notification. We recruited women using respondent-driven sampling, school-based sampling, and direct recruitment through social media and fliers. Participants in schools completed the survey as a paper-based, self-administered survey. Other participants could complete the survey in person, by phone as an interviewer-administered survey, or online. We recruited 162 participants, most in schools (n = 83; 51%) or by peer referral (n = 55; 34%). Only 1 woman completed the survey online. Thirty-one respondents (19%) reported a history of an unplanned first pregnancy, and 19 (12%) reported a history of a diagnosed sexually transmitted disease. Most women (n = 98; 63%) recognized the potential impact of Chlamydia trachomatis on fertility. The preferred site for chlamydia screening was the Indian Health Service Clinic (n = 114; 70%), but 79 women (41%) would accept a C. trachomatis test at a nonclinical testing site. Of the 56 women (35%) who would accept home testing, most preferred to get the test kit from a clinic. Our results suggest that Indian Health Service efforts to increase chlamydia screening in the clinic and through outreach may be more successful than promotion of home testing in this population.

A novel guinea pig model of Chlamydia trachomatis genital tract infection

NARCIS (Netherlands)

de Jonge, M.I.; Keizer, S.A.; El Moussaoui, H.M.; van Dorsten, L.; Azzawi, R.; van Zuilekom, H.I.; Peters, P.P.; van Opzeeland, F.J.; Dijk, L..; Nieuwland, R.; Roosenboom-Theunissen, H.W.; Vrijenhoek, M.P.; Debyser, I.; Verwey, P.J.; van Duijnhoven, W.G.; van den Bosch, J.F.; Nuijten, P.J.

2011-01-01

Genital Chlamydia trachomatis infections often result in pelvic inflammatory disease and sequelae including infertility and ectopic pregnancies. In addition to the already established murine models, the development of other animal models is necessary to study the safety and efficacy of prototype

Chlamydia trachomatis infection of the male genital tract: an update.

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Mackern-Oberti, Juan Pablo; Motrich, Rubén Darío; Breser, María Laura; Sánchez, Leonardo Rodolfo; Cuffini, Cecilia; Rivero, Virginia Elena

2013-11-01

Chlamydia trachomatis (CT) is the most prevalent cause of sexually transmitted diseases. Although the prevalence of chlamydial infection is similar in men and women, current research and screening are still focused on women, who develop the most severe complications, leaving the study of male genital tract (MGT) infection underrated. Herein, we reviewed the literature on genital CT infection with special focus on the MGT. Data indicate that CT certainly infects different parts of the MGT such as the urethra, seminal vesicles, prostate, epididymis and testis. However, whether or not CT infection has detrimental effects on male fertility is still controversial. The most important features of CT infection are its chronic nature and the presence of a mild inflammation that remains subclinical in most individuals. Chlamydia antigens and pathogen recognition receptors (PRR), expressed on epithelial cells and immune cells from the MGT, have been studied in the last years. Toll-like receptor (TLR) expression has been observed in the testis, epididymis, prostate and vas deferens. It has been demonstrated that recognition of chlamydial antigens is associated with TLR2, TLR4, and possibly, other PRRs. CT recognition by PRRs induces a local production of cytokines/chemokines, which, in turn, provoke chronic inflammation that might evolve in the onset of an autoimmune process in genetically susceptible individuals. Understanding local immune response along the MGT, as well as the crosstalk between resident leukocytes, epithelial, and stromal cells, would be crucial in inducing a protective immunity, thus adding to the design of new therapeutic approaches to a Chlamydia vaccine. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Caveolin-2 associates with intracellular chlamydial inclusions independently of caveolin-1

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Norkin Leonard C

2004-07-01

Full Text Available Abstract Background Lipid raft domains form in plasma membranes of eukaryotic cells by the tight packing of glycosphingolipids and cholesterol. Caveolae are invaginated structures that form in lipid raft domains when the protein caveolin-1 is expressed. The Chlamydiaceae are obligate intracellular bacterial pathogens that replicate entirely within inclusions that develop from the phagocytic vacuoles in which they enter. We recently found that host cell caveolin-1 is associated with the intracellular vacuoles and inclusions of some chlamydial strains and species, and that entry of those strains depends on intact lipid raft domains. Caveolin-2 is another member of the caveolin family of proteins that is present in caveolae, but of unknown function. Methods We utilized a caveolin-1 negative/caveolin-2 positive FRT cell line and laser confocal immunofluorescence techniques to visualize the colocalization of caveolin-2 with the chlamydial inclusions. Results We show here that in infected HeLa cells, caveolin-2, as well as caveolin-1, colocalizes with inclusions of C. pneumoniae (Cp, C. caviae (GPIC, and C. trachomatis serovars E, F and K. In addition, caveolin-2 also associates with C. trachomatis serovars A, B and C, although caveolin-1 did not colocalize with these organisms. Moreover, caveolin-2 appears to be specifically, or indirectly, associated with the pathogens at the inclusion membranes. Using caveolin-1 deficient FRT cells, we show that although caveolin-2 normally is not transported out of the Golgi in the absence of caveolin-1, it nevertheless colocalizes with chlamydial inclusions in these cells. However, our results also show that caveolin-2 did not colocalize with UV-irradiated Chlamydia in FRT cells, suggesting that in these caveolin-1 negative cells, pathogen viability and very likely pathogen gene expression are necessary for the acquisition of caveolin-2 from the Golgi. Conclusion Caveolin-2 associates with the chlamydial

Intracellular zinc flux causes reactive oxygen species mediated mitochondrial dysfunction leading to cell death in Leishmania donovani.

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Anjali Kumari

Full Text Available Leishmaniasis caused by Leishmania parasite is a global threat to public health and one of the most neglected tropical diseases. Therefore, the discovery of novel drug targets and effective drug is a major challenge and an important goal. Leishmania is an obligate intracellular parasite that alternates between sand fly and human host. To survive and establish infections, Leishmania parasites scavenge and internalize nutrients from the host. Nevertheless, host cells presents mechanism like nutrient restriction to inhibit microbial growth and control infection. Zinc is crucial for cellular growth and disruption in its homeostasis hinders growth and survival in many cells. However, little is known about the role of zinc in Leishmania growth and survival. In this study, the effect of zinc on the growth and survival of L.donovani was analyzed by both Zinc-depletion and Zinc-supplementation using Zinc-specific chelator N, N, N', N'-tetrakis (2-pyridylmethyl ethylenediamine (TPEN and Zinc Sulfate (ZnSO4. Treatment of parasites with TPEN rather than ZnSO4 had significantly affected the growth in a dose- and time-dependent manner. The pre-treatment of promastigotes with TPEN resulted into reduced host-parasite interaction as indicated by decreased association index. Zn depletion resulted into flux in intracellular labile Zn pool and increased in ROS generation correlated with decreased intracellular total thiol and retention of plasma membrane integrity without phosphatidylserine exposure in TPEN treated promastigotes. We also observed that TPEN-induced Zn depletion resulted into collapse of mitochondrial membrane potential which is associated with increase in cytosolic calcium and cytochrome-c. DNA fragmentation analysis showed increased DNA fragments in Zn-depleted cells. In summary, intracellular Zn depletion in the L. donovani promastigotes led to ROS-mediated caspase-independent mitochondrial dysfunction resulting into apoptosis-like cell death

Chlamydia felis exposure in companion dogs and cats in Lanzhou, China: a public health concern.

Science.gov (United States)

Wu, Song-Ming; Huang, Si-Yang; Xu, Min-Jun; Zhou, Dong-Hui; Song, Hui-Qun; Zhu, Xing-Quan

2013-05-21

Chlamydiaceae is a family of obligate intracellular pathogens with a worldwide distribution in many animal species, including humans. No information exists on the prevalence of Chlamydia felis infections in cats and dogs in Lanzhou, the geographical center of China. The aim of this study was to carry out a census of cats and dogs in Lanzhou and document the seroprevalence of C. felis exposure in these companion animals. In this study, blood samples were collected from 485 animals (221 cats and 264 pet dogs) in Lanzhou between November 2010 and July 2011 to identify antibodies against C. felis. Thirteen of 221 (5.9%) cats and 32 of 264 (12.1%) pet dogs were positive for C. felis infection using indirect hemagglutination at a cutoff of 1:16. The seroprevalence in household and stray cats was 3.9% and 14.3%, respectively, and the difference was statistically significant (P dogs ranged from 9.6 to 20.4%; however, the differences were not statistically significant (P > 0.05). This is the first report of the seroprevalence of C. felis exposure in cats and dogs in Lanzhou, northwestern China. Our results indicate that the presence of C. felis exposure in cats and dogs may pose a potential threat to human health.

Seroprevalence and Risk Factors of Chlamydia abortus Infection in Goats in Hunan Province, Subtropical China.

Science.gov (United States)

Hu, Shi-Feng; Li, Fen; Zheng, Wen-Bin; Liu, Guo-Hua

2018-01-23

Chlamydia abortus is an obligate intracellular Gram-negative bacteria, which can infect animals and human, including goats. However, little information on C. abortus infection is available in goats in Hunan province, subtropical China. To investigate the seroprevalence and risk factors of C. abortus infection in goats in Hunan province, China, a total of 911 goat blood samples were collected randomly from 14 herds having number of goats ranging from 1000 to 3000 from March 2014 to December 2015. Seropositive animals were found in 11 out of 14 (78.57%) goat herds with seroprevalence ranging from 0.00% to 29.94% in individual herds. Overall, the seroprevalence of C. abortus infection was different among regions (southern Hunan: 1.78%; northeast Hunan: 5.47%; and west Hunan: 15.29%), gender (male: 4.58% and female: 9.10%), seasons (spring: 5.97%; summer: 2.61%; autumn: 16.88%; and winter: 10.94%), and ages (year ≤1: 2.39%; 1 3: 17.57%). Risk factors for C. abortus infection were associated with region, season, and age in this study. To our knowledge, this is the first document to demonstrate the existence of C. abortus infection in goats, and the seroprevalence was 8.45% out of 911 goats in Hunan province.

Immunization against chlamydial genital infection in guinea pigs with UV-inactivated and viable chlamydiae administered by different routes

International Nuclear Information System (INIS)

Rank, R.G.; Batteiger, B.E.; Soderberg, L.S.

1990-01-01

Female guinea pigs were immunized with viable or UV light-inactivated chlamydiae, belonging to the species Chlamydia psittaci, by intravenous, subcutaneous, oral, or ocular routes. All animals were then inoculated vaginally with viable chlamydiae to determine the extent of protection against challenge infection induced by the various regimens. The course of genital infection was significantly reduced in intensity in all groups of animals except the unimmunized controls and those animals immunized orally with inactivated antigen. Guinea pigs immunized with viable antigen were more likely to develop resistance to challenge infection and, in general, had a significantly greater degree of protection than animals immunized with inactivated antigen. No one route seemed superior in producing a protective response. Animals in all groups demonstrating protection developed serum and secretion immunoglobulin G antibody responses to chlamydiae. Lymphocyte proliferative reactions to chlamydial antigen were variable among groups. Immunoblot analysis of serum and secretions indicated a wide range of antibody specificities, but most protected animals produced antibodies to the major outer membrane protein, lipopolysaccharide, and the 61-kilodalton protein. No definitive associations could be made between the increased ability of immunization with viable organisms to produce resistance to challenge infection and a particular immune parameter. These data indicate that viable chlamydiae given by various routes are able to induce a strong immune response which can provide resistance against reinfection in some cases or at least reduce the degree of infection to a greater degree than inactivated antigen. However, complete resistance to genital tract infection may be difficult to obtain and alternate immunizations strategies may have to be developed

Azithromycin effectiveness against intracellular infections of Francisella

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Mann Barbara J

2010-04-01

-type. Az treatment prolonged the survival of Galleria (G. mellonella infected with Francisella. Conclusion These studies demonstrate that Type A Francisella strains, as well as F. novicida and F. philomiragia, are sensitive to Az in vitro. Francisella LPS and the RND efflux pump may play a role in Az sensitivity. Az also has antimicrobial activity against intracellular Francisella, suggesting that the intracellular concentration of Az is high enough to be effective against multiple strains/species of Francisella, especially in macrophages. Az treatment prolonged survival an in vivo model of Francisella-infection.

Parachlamydia spp. and Related Chlamydia-like Organisms and Bovine Abortion

Science.gov (United States)

Borel, Nicole; Ruhl, Silke; Casson, Nicola; Kaiser, Carmen; Pospischil, Andreas

2007-01-01

Chlamydophila abortus and Waddlia chondrophila cause abortion in ruminants. We investigated the role of Parachlamydia acanthamoebae in bovine abortion. Results of immunohistochemical analyses were positive in 30 (70%) of 43 placentas from which Chlamydia-like DNA was amplified, which supports the role of Parachlamydia spp. in bovine abortion. PMID:18258043

Prevalence and risk factors of chlamydia infection in Hong Kong: A population-based geospatial household survey and testing.

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William Chi Wai Wong

Full Text Available Chlamydia causes infertility and increases risk of HIV infection, and population-based studies provide essential information for effective infection control and prevention. This study examined Chlamydia trachomatis prevalence and risk factors among a representative sample of 18-49-year-old residents in Hong Kong.Census boundary map of 412 constituency areas was used as primary sampling units to construct the sampling frame and, residential buildings and units were randomly selected using geospatial modelling. A questionnaire on sexual practice and health was conducted, and polymerase chain reaction was used to test the urine for genital chlamydial infection. Invitation letters were sent to the selected households and a team of interviewers were sent to recruit one subject per household. Prevalence data was weighted according to the 2011 census and risk factors identified through logistic regression.Among 881 participants (response rate of 24.5%, the overall Chlamydia trachomatis prevalence was low at 1.4% (95%CI 0.8-2.5% but sexually active young (18-26 years women had relatively high prevalence (5.8%, 95%CI 1.7-18.2% in Hong Kong. A unique U-shape disease burden was observed with peaks in younger and older (40-49 years women. Amongst the sexually active women, the risk factors of Chlamydia trachomatis infection were: younger age (aOR = 25.4, 95% CI 2.81-230; living alone (aOR = 8.99, 95% CI 1.46-55.40; and, among all the sexually active participants, males (including the male partners of the female participants who had travelled out of Hong Kong in the previous 12 months had higher risks of infection (aOR = 5.35; 95% CI 1.25-22.8. A core-peripheral geographical distribution of Chlamydia trachomatis prevalence was also observed.Young and older sexually active women in Hong Kong have high prevalence of chlamydia. Routine screening for sexually active women and young men should be considered. Further research on testing feasibility and linkage

Chlamydia abortus in Dairy Farms in Costa Rica

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Lisa Fonseca Salazar

2015-10-01

Full Text Available The aim of the present study was to determine the presence of antibodies against Chlamydia abortus in specialized dairy farms. A total of 608 blood samples were collected during 2012 from 24 dairy farms located in the Northern regions of the provinces of Alajuela (15 and Heredia (9, and surveys were carried out to determine management practices in these farms. Serum samples were analyzed by enzyme-linked immunosorbent assay (ELISA to detect antibodies against C. abortus (sensitivity 100.0%, specificity 99.7%. Only one serum yielded positive results (S/P 62 %, two sera weak positive results (S/P 51% and 52%, respectively, while the remaining sera (n=605 were negative in ELISA. Six months later, 22 animals that showed S/P values >22% in ELISA were analyzed again, yielding all negative results. Blood, milk, conjunctival and vulvar swabs from these animals were analyzed by Polymerase Chain Reaction (PCR, and only one vulvar swab tested positive for Chlamydia spp. The analysis of the management practices and results obtained with ELISA and PCR lead us to conclude that C. abortus is not significantly present (<0.5% in dairy farms in the Northern regions of the provinces of Heredia and Alajuela in Costa Rica.

Association of Chlamydia serology with HIV in Nigerian women *1H ...

African Journals Online (AJOL)

HASSAN PC

Nigerian Journal of Basic and Applied Science (December, 2016), 24(2): 15-22 ... 2Department of Obstetrics and Gynaecology, Ahmadu Bello University Teaching Hospital, Zaria. [*Corresponding author: E-mail: ... genus Chlamydia which includes organisms previously ..... evaluation of tubal-factor infertility (Persson,. 2002 ...

The Netherlands Chlamydia cohort study (NECCST) protocol to assess the risk of late complications following Chlamydia trachomatis infection in women.

Science.gov (United States)

Hoenderboom, B M; van Oeffelen, A A M; van Benthem, B H B; van Bergen, J E A M; Dukers-Muijrers, N H T M; Götz, H M; Hoebe, C J P A; Hogewoning, A A; van der Klis, F R M; van Baarle, D; Land, J A; van der Sande, M A B; van Veen, M G; de Vries, F; Morré, S A; van den Broek, I V F

2017-04-11

Chlamydia trachomatis (CT), the most common bacterial sexually transmitted infection (STI) among young women, can result in serious sequelae. Although the course of infection is often asymptomatic, CT may cause pelvic inflammatory disease (PID), leading to severe complications, such as prolonged time to pregnancy, ectopic pregnancy, and tubal factor subfertility. The risk of and risk factors for complications following CT-infection have not been assessed in a long-term prospective cohort study, the preferred design to define infections and complications adequately. In the Netherlands Chlamydia Cohort Study (NECCST), a cohort of women of reproductive age with and without a history of CT-infection is followed over a minimum of ten years to investigate (CT-related) reproductive tract complications. This study is a follow-up of the Chlamydia Screening Implementation (CSI) study, executed between 2008 and 2011 in the Netherlands. For NECCST, female CSI participants who consented to be approached for follow-up studies (n = 14,685) are invited, and prospectively followed until 2022. Four data collection moments are foreseen every two consecutive years. Questionnaire data and blood samples for CT-Immunoglobulin G (IgG) measurement are obtained as well as host DNA to determine specific genetic biomarkers related to susceptibility and severity of infection. CT-history will be based on CSI test outcomes, self-reported infections and CT-IgG presence. Information on (time to) pregnancies and the potential long-term complications (i.e. PID, ectopic pregnancy and (tubal factor) subfertility), will be acquired by questionnaires. Reported subfertility will be verified in medical registers. Occurrence of these late complications and prolonged time to pregnancy, as a proxy for reduced fertility due to a previous CT-infection, or other risk factors, will be investigated using longitudinal statistical procedures. In the proposed study, the occurrence of late complications following

Genital tract lesions in sexually mature Göttingen minipigs during the initial stages of experimental vaginal infection with Chlamydia trachomatis serovar D.

Science.gov (United States)

Erneholm, Karin; Lorenzen, Emma; Bøje, Sarah; Olsen, Anja Weinreich; Andersen, Peter; Cassidy, Joseph P; Follmann, Frank; Jensen, Henrik E; Agerholm, Jørgen S

2016-09-10

Chlamydia is one of the most common sexually transmitted diseases in humans worldwide, causing chronic lesions in the reproductive tract. Due to its often asymptomatic course, there is limited knowledge about the initial changes in the genital tract following infection. This study employs a novel sexually mature minipig model to investigate the initial histopathological changes following vaginal infection with Chlamydia trachomatis serovar D. A vaginal inoculation resulted in an infection primarily affecting the lower genital tract. The histopathological changes were characterized by a subepithelial inflammation consisting of neutrophils and mononuclear cells, followed by an increase in the number of plasma cells within the sub-epithelial stroma of the vagina. Detection of Chlamydia was associated with expression of cyclooxygenase-2 and interleukin-8 by superficial epithelial cells. The infection was self-limiting, with a duration of 7 days. Neutrophils, plasma cells and IL-8 have been linked with Chlamydia genital infection of unknown duration in human patients. In this study, we observe a similar pattern of local immune response/inflammation following experimental inoculation suggesting this porcine model shows promise as a model for translational chlamydia research.

Chlamydiosis: seroepidemiologic survey in a red deer (Cervus elaphus) population in Italy.

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Di Francesco, Antonietta; Donati, Manuela; Nicoloso, Sandro; Orlandi, Lilia; Baldelli, Raffaella; Salvatore, Daniela; Sarli, Giuseppe; Cevenini, Roberto; Morandi, Federico

2012-04-01

Chlamydiae are obligate, intracellular, gram-negative bacteria that are responsible for important diseases in humans, other mammals, and birds. Studies have shown that chlamydiae could be present in wild ruminants, but the serodiagnostic method most commonly used did not allow identification of chlamydial species. We determined the prevalence of antibodies to Chlamydia pecorum, Chlamydia suis, Chlamydia abortus, and Chlamydia psittaci in 271 red deer (Cervus elaphus) of a central Italian population, by using the microimmunofluorescence test that shows antibody response against genus-specific and species-specific antigens. No sera had detectable antibodies to C. pecorum and C. abortus. Antibodies were detected against C. psittaci (9.6%) and C. suis (3.3%). Antibody response could be related to contact of the red deer with birds and wild boars (Sus scrofa), respectively, and confirm an extended host range of individual Chlamydia species. In view of the potential zoonotic risk related to exposition of C. psittaci, our findings suggest surveillance of wild ruminants as potential reservoirs for chlamydiae.

Pilot study of a brief intervention based on the theory of planned behaviour and self-identity to increase chlamydia testing among young people living in deprived areas.

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Booth, Amy R; Norman, Paul; Goyder, Elizabeth; Harris, Peter R; Campbell, Michael J

2014-09-01

This study sought to estimate the effects of a novel intervention, compared with usual chlamydia testing promotion, on chlamydia test uptake and intentions among young people living in deprived areas. The intervention was based on the theory of planned behaviour, augmented with self-identity, and targeted the significant predictors of chlamydia testing intentions identified in the previous research. Cluster randomization was used to allocate college tutor groups (intervention n = 10; control n = 11) to the intervention or control group. The sample comprised 253 participants (intervention n = 145, control n = 108). The primary outcome was test offer uptake at the end of the session. Other outcomes measured at immediate follow-up were intention, attitude, subjective norm, perceived behavioural control, and self-identity. Generalized estimating equations, controlling for cluster effects and sexual activity, found a small but non-significant effect of condition on test offer uptake, OR = 1.65 (95% CI 0.70, 3.88) p = .25, with 57.5% of intervention participants accepting the offer of a test compared with 40.2% of control participants. Using the same analysis procedure, small-to-medium intervention effects were found on other outcome variables, including a significant effect on attitudes towards chlamydia testing, OR = 1.37 (95% CI 1.00, 1.87), p = .05. The results provide encouraging initial evidence that this theory-based intervention, targeting the key determinants of chlamydia testing, may help to improve chlamydia testing uptake in a high-risk group. They support the conduct of a larger trial to evaluate the effectiveness of the intervention. What is already known on this subject? Young people living in areas of increased socio-economic deprivation have been identified as a high-risk group for chlamydia. Previous research within an extended model of the theory of planned behaviour (TPB) found that attitude, subjective norm, perceived behavioural control, and self

Rationale and design of REACT: a randomised controlled trial assessing the effectiveness of home-collection to increase chlamydia retesting and detect repeat positive tests

OpenAIRE

Smith, Kirsty S; Hocking, Jane S; Chen, Marcus; Fairley, Christopher K; McNulty, Anna; Read, Phillip; Bradshaw, Catriona S; Tabrizi, Sepehr N; Wand, Handan; Saville, Marion; Rawlinson, William; Garland, Suzanne M; Donovan, Basil; Kaldor, John M; Guy, Rebecca

2014-01-01

Background Repeat infection with Chlamydia trachomatis is common and increases the risk of sequelae in women and HIV seroconversion in men who have sex with men (MSM). Despite guidelines recommending chlamydia retesting three months after treatment, retesting rates are low. We are conducting the first randomised controlled trial to assess the effectiveness of home collection combined with short message service (SMS) reminders on chlamydia retesting and reinfection rates in three risk groups. ...

Pitfalls of Internet-accessible diagnostic tests: inadequate performance of a CE-marked Chlamydia test for home use

OpenAIRE

Michel , Claude-Edouard C; Saison , Francis G; Joshi , Hrishikesh; Mahilum-Tapay , Lourdes M; Lee , Helen H

2009-01-01

Abstract Objectives: To evaluate the performance of a CE (Conformitee Europeenne)-marked home test for Chlamydia trachomatis (CT) that is available over the Internet. Methods: A total of 231 eligible women attending the Social Hygiene Clinic (SHC) or Obstetrics-Gynecology (OB-GYN) Clinic in Iloilo City, Philippines was recruited to an evaluation of the HandiLab-C Chlamydia home test (HandiLab-C). One vaginal swab was tested with HandiLab-C on-site and the second at Cambr...

Study of the prevalence and association of ocular chlamydial conjunctivitis in women with genital infection by Chlamydia trachomatis, Mycoplasma genitalium and Candida albicans attending outpatient clinic.

Science.gov (United States)

Khattab, Rania Abdelmonem; Abdelfattah, Maha Mohssen

2016-01-01

To determine the association between chlamydial conjunctivitis and genital infection by Chlamydia trachomatis, Mycoplasma genitalium and Candida albicans, in addition to the possible relationship between cultured bacterial pathogens and oculogenital chlamydial infection. This study was performed on 100 (50 symptomatic and 50 asymptomatic) women attending the Gynecological and Obstetric outpatient clinic of Alzahra hospital, Alazhar University. Simultaneously a conjunctival swab was taken from these patients. Polymerase chain reaction (PCR) was done on DNA extracted from both vaginal and conjunctival swab samples. Culture for both vaginal and conjunctival swabs was also done. Candida albicans was the predominant organism isolated by culture in 20% and 40% of conjunctival and vaginal swabs respectively. By the PCR method, ocular Chlamydia trachomatis was present in 60% of symptomatic women, while genital Chlamydia trachomatis infection was present in 30% of symptomatic women. The results of this method also indicated that 25/50 (50%) vaginal swabs were positive with PCR for Candida albicans versus 15/50 (30%) were PCR positive in conjunctival swab. Mycoplasma genitalium was present in only 10% of vaginal swabs. Concomitant oculogenital PCR positive results for Chlamydia trachomatis and Candida albicans were 30% and 28% respectively. Ocular Chlamydia trachomatis was associated with genital Chlamydia trachomatis in a high percentage of women followed by Candida albicans. Cultured bacterial organisms do not play a role in enhancement of Chlamydia trachomatis infection.

IL-10 polymorphism and cell-mediated immune response to Chlamydia trachomatis

DEFF Research Database (Denmark)

Öhman, H.; Tiitinen, A; Halttunen, M.

2006-01-01

Chlamydia trachomatis infection induces an inflammatory response that is crucial in resolving acute infection but may also play a key role in the pathogenesis of C trachomatis associated infertility. The immune response is linked to cytokine secretion pattern which is influenced by the host genetic...

Custo-efetividade do rastreamento da infecção por Chlamydia trachomatis em mulheres brasileiras

OpenAIRE

Elisa Tomazzini Andrade

2012-01-01

Resumo: Introdução: A importância da infecção por Chlamydia trachomatis não está relacionada apenas à sua elevada frequência, mas principalmente pelas graves repercussões no aparelho genital feminino. Apenas 30% das pacientes infectadas apresentam sintomas e só 40% terão sinais que possam evidenciar sua presença. Cerca de 70% dos casos de infecção por Chlamydia trachomatis são assintomáticos e acabam não sendo diagnosticados, havendo, portanto a necessidade de programa de rastreamento para di...

Search for microRNAs expressed by intracellular bacterial pathogens in infected mammalian cells.

Science.gov (United States)

Furuse, Yuki; Finethy, Ryan; Saka, Hector A; Xet-Mull, Ana M; Sisk, Dana M; Smith, Kristen L Jurcic; Lee, Sunhee; Coers, Jörn; Valdivia, Raphael H; Tobin, David M; Cullen, Bryan R

2014-01-01

MicroRNAs are expressed by all multicellular organisms and play a critical role as post-transcriptional regulators of gene expression. Moreover, different microRNA species are known to influence the progression of a range of different diseases, including cancer and microbial infections. A number of different human viruses also encode microRNAs that can attenuate cellular innate immune responses and promote viral replication, and a fungal pathogen that infects plants has recently been shown to express microRNAs in infected cells that repress host cell immune responses and promote fungal pathogenesis. Here, we have used deep sequencing of total expressed small RNAs, as well as small RNAs associated with the cellular RNA-induced silencing complex RISC, to search for microRNAs that are potentially expressed by intracellular bacterial pathogens and translocated into infected animal cells. In the case of Legionella and Chlamydia and the two mycobacterial species M. smegmatis and M. tuberculosis, we failed to detect any bacterial small RNAs that had the characteristics expected for authentic microRNAs, although large numbers of small RNAs of bacterial origin could be recovered. However, a third mycobacterial species, M. marinum, did express an ∼ 23-nt small RNA that was bound by RISC and derived from an RNA stem-loop with the characteristics expected for a pre-microRNA. While intracellular expression of this candidate bacterial microRNA was too low to effectively repress target mRNA species in infected cultured cells in vitro, artificial overexpression of this potential bacterial pre-microRNA did result in the efficient repression of a target mRNA. This bacterial small RNA therefore represents the first candidate microRNA of bacterial origin.

Search for microRNAs expressed by intracellular bacterial pathogens in infected mammalian cells.

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Yuki Furuse

Full Text Available MicroRNAs are expressed by all multicellular organisms and play a critical role as post-transcriptional regulators of gene expression. Moreover, different microRNA species are known to influence the progression of a range of different diseases, including cancer and microbial infections. A number of different human viruses also encode microRNAs that can attenuate cellular innate immune responses and promote viral replication, and a fungal pathogen that infects plants has recently been shown to express microRNAs in infected cells that repress host cell immune responses and promote fungal pathogenesis. Here, we have used deep sequencing of total expressed small RNAs, as well as small RNAs associated with the cellular RNA-induced silencing complex RISC, to search for microRNAs that are potentially expressed by intracellular bacterial pathogens and translocated into infected animal cells. In the case of Legionella and Chlamydia and the two mycobacterial species M. smegmatis and M. tuberculosis, we failed to detect any bacterial small RNAs that had the characteristics expected for authentic microRNAs, although large numbers of small RNAs of bacterial origin could be recovered. However, a third mycobacterial species, M. marinum, did express an ∼ 23-nt small RNA that was bound by RISC and derived from an RNA stem-loop with the characteristics expected for a pre-microRNA. While intracellular expression of this candidate bacterial microRNA was too low to effectively repress target mRNA species in infected cultured cells in vitro, artificial overexpression of this potential bacterial pre-microRNA did result in the efficient repression of a target mRNA. This bacterial small RNA therefore represents the first candidate microRNA of bacterial origin.

The distribution of chlamydia, gonorrhoea and syphilis cases across states and counties in the USA, 2007.

Science.gov (United States)

Chesson, Harrell W; Sternberg, Maya; Leichliter, Jami S; Aral, Sevgi O

2010-12-01

To examine the distribution of chlamydia, gonorrhoea and syphilis in the USA through the use of Lorenz curves and Gini coefficients. The distribution of three sexually transmitted diseases (STD; chlamydia, gonorrhoea and primary and secondary syphilis) was examined across states and counties in the USA in 2007, based on reported case numbers. Gini coefficients, which can range from 0 (equality in STD rates across geographical units) to 1 (complete inequality such that all STD occur in one geographical unit) were calculated. Overall, chlamydia was the most evenly distributed and syphilis was the most concentrated of the three STD examined. The Gini coefficients for chlamydia, gonorrhoea and syphilis were 0.121, 0.255 and 0.334, respectively, when examined across states, and 0.319, 0.494 and 0.630, respectively, when examined across counties. Differences in Gini coefficients were observed when the STD distributions were examined by sex, race/ethnicity and age group. The use of Lorenz curves and Gini coefficients can help to assess inequalities in the distribution of STD, to gauge the suitability of geographically targeted interventions, and to help in determining the epidemic phase of STD. Having a better understanding of the disparities in the distribution of STD across states and counties by sex, race/ethnicity and age group might help in understanding why disparities in STD rates exist across different groups and in developing interventions to address these disparities.

Isolation of Chlamydia trachomatis or Ureaplasma urealyticum from the synovial fluid of patients with Reiter's syndrome

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Pavlica Ljiljana

2003-01-01

Full Text Available Background. The aim of this study was to contribute to the insight of the role of the infectious agent in ethiopathogenesis of the Reiter’s syndrome development, which could directly influence the choise of treatment of these patients. Methods. Eighteen patients with urogenital form of the Reiter’s syndrome and 16 controls (6 with rheumatoid arthritis and 10 with pigmented villonodular synovitis were included in the study. In all patients standard laboratory analyses of the blood, urine and stool were made; antibody titer to Chlamydia trachomatis and Ureaplasma urealyticum was determined in synovial fluid and serum; isolation of Chlamydia trachomatis and Ureaplasma urealyticum in urethral, cervical and conjunctival swabs, as well as in prostatic and synovial fluid, was also made. HLA typing was done, too. Chlamydia was isolated in the McCoy cell culture treated with cycloheximide while Ureaplasma was identified according to its biochemical properties grown on cell-free liquid medium. Results. Chlamydia trachomatis was isolated from the synovial fluid of 4 patients with Reiter's syndrome 22.2%, while Ureaplasma urealyticum was isolated in 7 of them (38.9%. These microorganisms were not found in any synovial fluid of the control group patients. Conclusion. Presence of these bacteria in the inflamed joint might be an important factor in etiopathogenesis of this disease, and it supports the hypothesis that arthritis in Reiter's syndrome is probably of the infectious origin.

Chlamydia screening is not cost-effective at low participation rates: evidence from a repeated register-based implementation study in The Netherlands

NARCIS (Netherlands)

de Wit, G. Ardine; Over, Eelco A. B.; Schmid, Boris V.; van Bergen, Jan E. A. M.; van den Broek, Ingrid V. F.; van der Sande, Marianne A. B.; Welte, Robert; Op de Coul, Eline L. M.; Kretzschmar, Mirjam E.

2015-01-01

In three pilot regions of The Netherlands, all 16-29 year olds were invited to participate in three annual rounds of Chlamydia screening. The aim of the present study is to evaluate the cost-effectiveness of repeated Chlamydia screening, based on empirical data. A mathematical model was employed to

Intracellular contacts - effect of survival curve of mammal cells on the Dq value

International Nuclear Information System (INIS)

Durand, R.E.; Sutherland, R.M.

1980-01-01

Survival increase is observed in cells of the Chinese hamster of the V79-171 line which grow in the composition of multicell spheroids as compared with the survival after irradiation in a single state. The ratio of the Dsub(q) cell value in the composition of spheroids to Dsub(q) of separately growing cells increases as the mitotic cycle proceeds from the minimum value of 1.3 for cells in the Gi phase to the maximum value of 2.2 for cells in a late S-phase. The increase of survival during growth in the composition of spheroids is not characteristic for all cell types. Only a part of cultured MNNG-mutants of cells of the V79-171 Chinese hamster reveal radiomodifying effect of cell contact acting [ru

Brucella abortus nicotinamidase (PncA) contributes to its intracellular replication and infectivity in mice.

Science.gov (United States)

Kim, Suk; Kurokawa, Daisuke; Watanabe, Kenta; Makino, Sou-Ichi; Shirahata, Toshikazu; Watarai, Masahisa

2004-05-15

Brucella spp. are facultative intracellular pathogens that have the ability to survive and multiply in professional and non-professional phagocytes, and cause abortion in domestic animals and undulant fever in humans. The mechanism and factors of virulence are not fully understood. Nicotinamidase/pyrazinamidase mutant (pncA mutant) of Brucella abortus failed to replicate in HeLa cells, and showed a lower rate of intracellular replication than that of wild-type strain in macrophages. Addition of nicotinic acid, but not nicotinamide, into medium supported intracellular replication of pncA mutant in HeLa cells and macrophages. The pncA mutant was not co-localizing with either late endosomes or lysosomes. The B. abortus virB4 mutant was completely cleared from the spleens of mice after 4 weeks, while the pncA mutant showed a 1.5-log reduction of the number of bacteria isolated from spleens after 10 weeks. Although pncA mutant showed reduced virulence in mice and defective intracellular replication, its ability to confer protection against the virulent B. abortus strain 544 was fully retained. These results suggest that PncA does not contribute to intracellular trafficking of B. abortus, but contributes to utilization of nutrients required for intracellular growth. Our results indicate that detailed characterizations of the pncA mutant may help the improvement of currently available live vaccines. Copyright 2004 Federation of European Microbiological Societies

Evidence for an intracellular niche for Bordetella pertussis in broncho-alveolar lavage cells of mice

NARCIS (Netherlands)

Hellwig, SMM; Hazenbos, WLW; van de Winkel, JGJ; Mooi, FR

1999-01-01

Bordetella pertussis can attach, invade and survive intracellularly in human macrophages in vitro. To study the significance of this bacterial feature in vivo, we analyzed the presence of viable bacteria in broncho-alveolar lavage (BAL) cells of mice infected with B, pertussis. We found B. pertussis

Resolution of Chlamydia trachomatis Infection Is Associated with a Distinct T Cell Response Profile.

Science.gov (United States)

Picard, Michele D; Bodmer, Jean-Luc; Gierahn, Todd M; Lee, Alexander; Price, Jessica; Cohane, Kenya; Clemens, Veronica; DeVault, Victoria L; Gurok, Galina; Kohberger, Robert; Higgins, Darren E; Siber, George R; Flechtner, Jessica Baker; Geisler, William M

2015-11-01

Chlamydia trachomatis is the causative agent of the most frequently reported bacterial sexually transmitted infection, the total burden of which is underestimated due to the asymptomatic nature of the infection. Untreated C. trachomatis infections can cause significant morbidities, including pelvic inflammatory disease and tubal factor infertility (TFI). The human immune response against C. trachomatis, an obligate intracellular bacterium, is poorly characterized but is thought to rely on cell-mediated immunity, with CD4(+) and CD8(+) T cells implicated in protection. In this report, we present immune profiling data of subjects enrolled in a multicenter study of C. trachomatis genital infection. CD4(+) and CD8(+) T cells from subjects grouped into disease-specific cohorts were screened using a C. trachomatis proteomic library to identify the antigen specificities of recall T cell responses after natural exposure by measuring interferon gamma (IFN-γ) levels. We identified specific T cell responses associated with the resolution of infection, including unique antigens identified in subjects who spontaneously cleared infection and different antigens associated with C. trachomatis-related sequelae, such as TFI. These data suggest that novel and unique C. trachomatis T cell antigens identified in individuals with effective immune responses can be considered as targets for vaccine development, and by excluding antigens associated with deleterious sequelae, immune-mediated pathologies may be circumvented. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Molecular biology of the Chlamydia pneumoniae surface

DEFF Research Database (Denmark)

Christiansen, Gunna; Østergaard, Lars; Birkelund, Svend

1997-01-01

surface differs from that of Chlamydia trachomatis. In order to study the surface of C. pneumoniae we generated monoclonal antibodies (MAbs) against C. pneumoniae strain VR-1310 and selected 14 MAbs that reacted with the surface of C. pneumoniae. All MAbs reacted in immunoelectron microscopy...... with the surface of both whole C. pneumoniae VR-1310 elementary bodies and with purified sarcosyl extracted outer membrane complexes. However, only 2 of the MAbs reacted in immunoblotting with C. pneumoniae proteins and only with antigen that had not been heat treated in SDS-sample buffer. This indicates...

Depletion of autophagy-related genes ATG3 and ATG5 in Tenebrio molitor leads to decreased survivability against an intracellular pathogen, Listeria monocytogenes.

Science.gov (United States)

Tindwa, Hamisi; Jo, Yong Hun; Patnaik, Bharat Bhusan; Noh, Mi Young; Kim, Dong Hyun; Kim, Iksoo; Han, Yeon Soo; Lee, Yong Seok; Lee, Bok Luel; Kim, Nam Jung

2015-01-01

Macroautophagy (autophagy) is an evolutionarily conserved catabolic process involved in physiological and developmental processes including cell survival, death, and innate immunity. Homologues of most of 36 originally discovered autophagy-related (ATG) genes in yeast have been characterized in higher eukaryotes including insects. In this study, the homologues of ATG3 (TmATG3) and ATG5 (TmATG5) were isolated from the coleopteran beetle, Tenebrio molitor by expressed sequence tag and RNAseq approaches. The cDNA of TmATG3 and TmATG5 comprise open-reading frame sizes of 963 and 792 bp encoding polypeptides of 320 and 263 amino acid residues, respectively. TmATG3 and TmATG5 mRNA are expressed in all developmental stages, and mainly in fat body and hemocytes of larvae. TmATG3 and TmATG5 showed an overall sequence identity of 58-95% to other insect Atg proteins. There exist clear one-to-one orthologs of TmATG3 and TmATG5 in Tribolium and that they clustered together in the gene tree. Depletion of TmATG3 and TmATG5 by RNA interference led to a significant reduction in survival ability of T. molitor larvae against an intracellular pathogen, Listeria monocytogenes. Six days post-Listeria challenge, the survival rate in the dsEGFP-injected (where EGFP is enhanced green fluorescent protein) control larvae was significantly higher (55%) compared to 4 and 3% for TmATG3 and TmATG5 double-stranded RNA injected larvae, respectively. These data suggested that TmATG3 and TmATG5 may play putative role in mediating autophagy-based clearance of Listeria in T. molitor model. © 2014 Wiley Periodicals, Inc.

Trends in chlamydia and gonorrhea positivity among heterosexual men and men who have sex with men attending a large urban sexual health service in Australia, 2002-2009

Science.gov (United States)

2011-01-01

Background To determine whether chlamydia positivity among heterosexual men (MSW) and chlamydia and gonorrhea positivity among men who have sex with men (MSM), are changing. Methods Computerized records for men attending a large sexual health clinic between 2002 and 2009 were analyzed. Chlamydia and gonorrhea positivity were calculated and logistic regression used to assess changes over time. Results 17769 MSW and 8328 MSM tested for chlamydia and 7133 MSM tested for gonorrhea. In MSW, 7.37% (95% CI: 6.99-7.77) were chlamydia positive; the odds of chlamydia positivity increased by 4% per year (OR = 1.04; 95% CI: 1.01-1.07; p = 0.02) after main risk factors were adjusted for. In MSM, 3.70% (95% CI: 3.30-4.14) were urethral chlamydia positive and 5.36% (95% CI: 4.82-5.96) were anal chlamydia positive; positivity could not be shown to have changed over time. In MSM, 3.05% (95% CI: 2.63-3.53) tested anal gonorrhea positive and 1.83% (95% CI: 1.53-2.18) tested pharyngeal gonorrhea positive. Univariate analysis found the odds of anal gonorrhea positivity had decreased (OR = 0.93; 95% CI: 0.87-1.00; p = 0.05), but adjusting for main risk factors resulted in no change. Urethral gonorrhea cases in MSM as a percentage of all MSM tested for gonorrhea also fell (p gonorrhea prevalence among MSM is stable or declining. High STI testing rates among MSM in Australia may explain differences in STI trends between MSM and MSW. PMID:21639943

Sen debut af neonatal pneumoni forårsaget af Chlamydia trachomatis

DEFF Research Database (Denmark)

Schmidt, Birgitte Johanne; Hermansen, Mette Nortman

2013-01-01

A newborn colonized with Chlamydia trachomatis will often show symptoms of conjunctivitis and/or pneumonia. We report a case of interstitial pneumonia caused by C. trachomatis in a 2-month-old boy admitted with RSV. We point to the importance of C. trachomatis in the differential diagnostics...

Type IV pili in Francisella – A virulence trait in an intracellular pathogen

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Emelie eNäslund Salomonsson

2011-02-01

Full Text Available Francisella tularensis is a highly virulent intracellular human pathogen that is capable of rapid proliferation in the infected host. Mutants affected in intracellular survival and growth are highly attenuated which highlights the importance of the intracellular phase of the infection. Genomic analysis has revealed that Francisella encodes all genes required for expression of functional type IV pili (Tfp, and in this focused review we summarise recent findings regarding this system in the pathogenesis of tularemia. Tfp are dynamic adhesive structures that have been identified as major virulence determinants in several human pathogens, but it is not obvious what role these structures could have in an intracellular pathogen like Francisella. In the human pathogenic strains, genes required for secretion and assembly of Tfp and one pilin, PilA, have shown to be required for full virulence. Importantly, specific genetic differences have been identified between the different Francisella subspecies where in the most pathogenic type A variants all genes are intact while several Tfp genes are pseudogenes in the less pathogenic type B strains. This suggests that there has been a selection for expression of Tfp with different properties in the different subspecies. There is also a possibility that the genetic differences reflect adaption to different environmental niches of the subspecies and plays a role in transmission of tularemia. This is also in line with recent findings where Tfp pilins are found to be glycosylated which could reflect a role for Tfp in the environment to promote survival and transmission. We are still far from understanding the role of Tfp in virulence and transmission of tularemia, but with the genomic information and genetic tools available we are in a good position to address these issues in the future.

Current crisis or artifact of surveillance: insights into rebound chlamydia rates from dynamic modelling

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Vickers David M

2010-03-01

Full Text Available Abstract Background After initially falling in the face of intensified control efforts, reported rates of sexually transmitted chlamydia in many developed countries are rising. Recent hypotheses for this phenomenon have broadly focused on improved case finding or an increase in the prevalence. Because of many complex interactions behind the spread of infectious diseases, dynamic models of infection transmission are an effective means to guide learning, and assess quantitative conjectures of epidemiological processes. The objective of this paper is to bring a unique and robust perspective to observed chlamydial patterns through analyzing surveillance data with mathematical models of infection transmission. Methods This study integrated 25-year testing volume data from the Canadian province of Saskatchewan with one susceptible-infected-treated-susceptible and three susceptible-infected-treated-removed compartmental models. Calibration of model parameters to fit observed 25-year case notification data, after being combined with testing records, placed constraints on model behaviour and allowed for an approximation of chlamydia prevalence to be estimated. Model predictions were compared to observed case notification trends, and extensive sensitivity analyses were performed to confirm the robustness of model results. Results Model predictions accurately mirrored historic chlamydial trends including an observed rebound in the mid 1990s. For all models examined, the results repeatedly highlighted that increased testing volumes, rather than changes in the sensitivity and specificity of testing technologies, sexual behaviour, or truncated immunological responses brought about by treatment can, explain the increase in observed chlamydia case notifications. Conclusions Our results highlight the significant impact testing volume can have on observed incidence rates, and that simple explanations for these observed increases appear to have been dismissed in

The Number, Organization, and Size of Polymorphic Membrane Protein Coding Sequences as well as the Most Conserved Pmp Protein Differ within and across Chlamydia Species.

Science.gov (United States)

Van Lent, Sarah; Creasy, Heather Huot; Myers, Garry S A; Vanrompay, Daisy

2016-01-01

Variation is a central trait of the polymorphic membrane protein (Pmp) family. The number of pmp coding sequences differs between Chlamydia species, but it is unknown whether the number of pmp coding sequences is constant within a Chlamydia species. The level of conservation of the Pmp proteins has previously only been determined for Chlamydia trachomatis. As different Pmp proteins might be indispensible for the pathogenesis of different Chlamydia species, this study investigated the conservation of Pmp proteins both within and across C. trachomatis,C. pneumoniae,C. abortus, and C. psittaci. The pmp coding sequences were annotated in 16 C. trachomatis, 6 C. pneumoniae, 2 C. abortus, and 16 C. psittaci genomes. The number and organization of polymorphic membrane coding sequences differed within and across the analyzed Chlamydia species. The length of coding sequences of pmpA,pmpB, and pmpH was conserved among all analyzed genomes, while the length of pmpE/F and pmpG, and remarkably also of the subtype pmpD, differed among the analyzed genomes. PmpD, PmpA, PmpH, and PmpA were the most conserved Pmp in C. trachomatis,C. pneumoniae,C. abortus, and C. psittaci, respectively. PmpB was the most conserved Pmp across the 4 analyzed Chlamydia species. © 2016 S. Karger AG, Basel.

Systematic screening with information and home sampling for genital Chlamydia trachomatis infections in young men and women in Norway: a randomized controlled trial.

Science.gov (United States)

Kløvstad, Hilde; Natås, Olav; Tverdal, Aage; Aavitsland, Preben

2013-01-23

As most genital Chlamydia trachomatis infections are asymptomatic, many patients do not seek health care for testing. Infections remain undiagnosed and untreated. We studied whether screening with information and home sampling resulted in more young people getting tested, diagnosed and treated for chlamydia in the three months following the intervention compared to the current strategy of testing in the health care system. We conducted a population based randomized controlled trial among all persons aged 18-25 years in one Norwegian county (41 519 persons). 10 000 persons (intervention) received an invitation by mail with chlamydia information and a mail-back urine sampling kit. 31 519 persons received no intervention and continued with usual care (control). All samples from both groups were analysed in the same laboratory. Information on treatment was obtained from the Norwegian Prescription Database (NorPD). We estimated risk ratios and risk differences of being tested, diagnosed and treated in the intervention group compared to the control group. In the intervention group 16.5% got tested and in the control group 3.4%, risk ratio 4.9 (95% CI 4.5-5.2). The intervention led to 2.6 (95% CI 2.0-3.4) times as many individuals being diagnosed and 2.5 (95% CI 1.9-3.4) times as many individuals receiving treatment for chlamydia compared to no intervention in the three months following the intervention. In Norway, systematic screening with information and home sampling results in more young people being tested, diagnosed and treated for chlamydia in the three months following the intervention than the current strategy of testing in the health care system. However, the study has not established that the intervention will reduce the chlamydia prevalence or the risk of complications from chlamydia.

Intramacrophage survival of uropathogenic Escherichia coli: Differences between diverse clinical isolates and between mouse and human macrophages

KAUST Repository

Bokil, Nilesh J.

2011-11-01

Uropathogenic E. coli (UPEC) are the primary cause of urinary tract infections. Recent studies have demonstrated that UPEC can invade and replicate within epithelial cells, suggesting that this bacterial pathogen may occupy an intracellular niche within the host. Given that many intracellular pathogens target macrophages, we assessed the interactions between UPEC and macrophages. Colonization of the mouse bladder by UPEC strain CFT073 resulted in increased expression of myeloid-restricted genes, consistent with the recruitment of inflammatory macrophages to the site of infection. In in vitro assays, CFT073 was able to survive within primary mouse bone marrow-derived macrophages (BMM) up to 24h post-infection. Three additional well-characterized clinical UPEC isolates associated with distinct UTI symptomatologies displayed variable long-term survival within BMM. UPEC strains UTI89 and VR50, originally isolated from patients with cystitis and asymptomatic bacteriuria respectively, showed elevated bacterial loads in BMM at 24h post-infection as compared to CFT073 and the asymptomatic bacteriuria strain 83972. These differences did not correlate with differential effects on macrophage survival or initial uptake of bacteria. E. coli UTI89 localized to a Lamp1 + vesicular compartment within BMM. In contrast to survival within mouse BMM, intracellular bacterial loads of VR50 were low in both human monocyte-derived macrophages (HMDM) and in human T24 bladder epithelial cells. Collectively, these data suggest that some UPEC isolates may subvert macrophage anti-microbial pathways, and that host species differences may impact on intracellular UPEC survival. © 2011 Elsevier GmbH.

Construction of a highly flexible and comprehensive gene collection representing the ORFeome of the human pathogen Chlamydia pneumoniae

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Maier Christina J

2012-11-01

Full Text Available Abstract Background The Gram-negative bacterium Chlamydia pneumoniae (Cpn is the leading intracellular human pathogen responsible for respiratory infections such as pneumonia and bronchitis. Basic and applied research in pathogen biology, especially the elaboration of new mechanism-based anti-pathogen strategies, target discovery and drug development, rely heavily on the availability of the entire set of pathogen open reading frames, the ORFeome. The ORFeome of Cpn will enable genome- and proteome-wide systematic analysis of Cpn, which will improve our understanding of the molecular networks and mechanisms underlying and governing its pathogenesis. Results Here we report the construction of a comprehensive gene collection covering 98.5% of the 1052 predicted and verified ORFs of Cpn (Chlamydia pneumoniae strain CWL029 in Gateway® ‘entry’ vectors. Based on genomic DNA isolated from the vascular chlamydial strain CV-6, we constructed an ORFeome library that contains 869 unique Gateway® entry clones (83% coverage and an additional 168 PCR-verified ‘pooled’ entry clones, reaching an overall coverage of ~98.5% of the predicted CWL029 ORFs. The high quality of the ORFeome library was verified by PCR-gel electrophoresis and DNA sequencing, and its functionality was demonstrated by expressing panels of recombinant proteins in Escherichia coli and by genome-wide protein interaction analysis for a test set of three Cpn virulence factors in a yeast 2-hybrid system. The ORFeome is available in different configurations of resource stocks, PCR-products, purified plasmid DNA, and living cultures of E. coli harboring the desired entry clone or pooled entry clones. All resources are available in 96-well microtiterplates. Conclusion This first ORFeome library for Cpn provides an essential new tool for this important pathogen. The high coverage of entry clones will enable a systems biology approach for Cpn or host–pathogen analysis. The high yield of

Intracellular thiol levels and radioresistance: Studies with glutathione and glutathione mono ethyl ester

International Nuclear Information System (INIS)

Astor, M.B.; Meister, A.; Anderson, M.E.

1987-01-01

Intracellular thiols such as glutathione (GSH) protect cells against free radicals formed during oxidative metabolism or from exposure to drugs or ionizing radiation. The role of intracellular GSH in the repair of radiation induced free radical damage was studied using GSH or its analog glutathione mono ethyl ester (GEE), which readily penetrates into the cell. Chinese hamster V79 cells with normal GSH levels were afforded equal protection under aerated and hypoxic conditions (DMF = 1.2 OER = 3.7) by both 10 mM GSH and GEE although GEE had raised interacellular GSH levels three-fold. Growth of V79 cells in cysteine free media resulted in undetectable levels of GSH and OER of 2.2 with no change in aerated survival. Restoration of intracellular GSH by 10 mM GEE resulted in an increase of the OER from 2.2. to 3.8 (DMF = 1.7). Only 14% of the intracellular GSH needs to be repleted to give an OER of 3.0. These experiments provide evidence that thiols do play a role in the oxygen effect and are present at levels in excess of what is necessary for maximal radioprotection

Prevalence of genital Chlamydia trachomatis in Iran: a systematic review and meta-analysis.

Science.gov (United States)

Ahmadi, Mohammad Hossein; Mirsalehian, Akbar; Bahador, Abbas

2015-09-01

To determine the overall prevalence of Chlamydia trachomatis in Iranian males and females and to find out the effect of this bacterium on fertility potential and its association with urogenital symptoms. We searched both English and Persian electronic databases using keywords 'Chlamydia', 'Chlamydia trachomatis', 'prevalence', 'incidence', 'frequency', 'epidemiology' and 'Iran'. Finally, after some exclusion, 34 studies from different regions of Iran were included in our study, and a meta-analysis was performed to determine pooled prevalence estimates for each group. C. trachomatis prevalence for women and men was high and ranged from 0 to 32.7% and 0 to 23.3%, respectively (95% CI). The pooled prevalence of the bacterium in the female population was 12.3% (95% CI: 10.6-14.2%) and in men was 10.9% (95% CI: 7.6-15.4%). A high level of heterogeneity was seen for both men (I(2)  = 77.4%; P females analysis of symptomatic/infertile group with asymptomatic/fertile group in females, the overall OR was above 1 and the overall P-value was below zero. This bacterium may play a role in female infertility or be associated with clinical manifestations; thus, planning national programmes for adequate diagnosis of genital infections caused by this pathogen is necessary. Furthermore, screening strategies, particularly for asymptomatic individuals, and treatment of infected people can reduce consequent complications.

Laser therapy in women genital Chlamydia trachomatis infection complicated with PID and infertility

Science.gov (United States)

Brinzan, Daniela; Paiusan, Lucian; Smeu, Claudia-Ramona

2018-04-01

Genital Chlamydia Trachomatis infection is one of the most common sexually transmitted infections with more than 50 million new cases occurred globally every year. Underdiagnosed and untreated, it can generate long term severe complications including PID, infertility, ectopic pregnancy and chronic pelvic pain. Among 20 patients diagnosed with PID and infertility in our medical office during one year, we selected a study group of 10 patients with genital Chlamydia Trachomatis infection. The diagnostic methods used were anamnesis, clinical examination, Pap smear, bacteriological and serological tests, ultra sound examination. The group of patients selected was monitored for one year. The treatment took into account general measures for both partners and specific measures (antibiotic treatment and focused laser therapy). The initial group was split in two, group A treated only with antibiotics and group B treated with both antibiotics and laser therapy. All the 5 patients of group B presented an improvement of the clinical manifestations and 3 of them ended up with pregnancy. On the other hand, in group B, only one patient manifested total disappearance of pains and the infertility persisted for all. It is noteworthy that the association of laser therapy in the treatment of Chlamydia Trachomatis infection has brought significant improvement in the inflammatory processes of internal genitalia (PID) and in the fertility of the couple.

Detection of all Chlamydophila and Chlamydia spp. of veterinary interest using species-specific real-time PCR assays.

Science.gov (United States)

Pantchev, Alexandra; Sting, Reinhard; Bauerfeind, Rolf; Tyczka, Judith; Sachse, Konrad

2010-12-01

The aim of the present study was to analyse the occurrence of chlamydiae in several mammalian host species. Clinical samples that previously tested positive in a Chlamydiaceae-specific real-time PCR were retested using six species-specific real-time PCR assays to identify the chlamydial species involved. Chlamydophila (Cp.) abortus was the agent most frequently found in cattle, sheep, horses, goats, and pigs. Detection in cattle of Cp. psittaci (11% of samples) and Chlamydia (C.) suis (9%), as well as Cp. psittaci in a goat sample was somewhat unexpected. DNA of two different chlamydiae was identified in 56 (12.7%) of 440 samples tested. Cp. felis was the predominant species found in cats, while in guinea pigs and rabbits only Cp. caviae was detected. Interestingly, the latter two pathogens were also identified in samples from dogs. The data show that mixed chlamydial infections are not rare and suggest an extended host range of individual species. Copyright © 2009 Elsevier Ltd. All rights reserved.

Using the Theory of Planned Behavior to identify key beliefs underlying chlamydia testing intentions in a sample of young people living in deprived areas.

Science.gov (United States)

Booth, Amy R; Norman, Paul; Harris, Peter R; Goyder, Elizabeth

2015-09-01

The Theory of Planned Behavior was used to identify the key behavioural, normative and control beliefs underlying intentions to test regularly for chlamydia among young people living in socially and economically deprived areas - a high-risk group for infection. Participants (N = 278, 53% male; mean age 17 years) were recruited from a vocational college situated in an area in the most deprived national quintile (England). Participants completed measures of behavioural, normative and control beliefs, plus intention to test regularly for chlamydia. The behavioural, normative and control beliefs most strongly correlated with intentions to test regularly for chlamydia were beliefs about stopping the spread of infection, partners' behaviour and the availability of testing. These beliefs represent potential targets for interventions to increase chlamydia testing among young people living in deprived areas. © The Author(s) 2013.

Low prevalence of the new variant of Chlamydia trachomatis in Denmark

DEFF Research Database (Denmark)

Jensen, J.S.; Westh, Henrik T.

2008-01-01

We estimated the prevalence of the new variant of Chlamydia trachomatis in Denmark. Fifty consecutive C trachomatis urine samples from each of the 14 regional microbiology laboratories were initially tested and re-analysed with a real-time C trachomatis PCR assay targeting the 16S rRNA gene...

Macrophage activation induced by Brucella DNA suppresses bacterial intracellular replication via enhancing NO production.

Science.gov (United States)

Liu, Ning; Wang, Lin; Sun, Changjiang; Yang, Li; Tang, Bin; Sun, Wanchun; Peng, Qisheng

2015-12-01

Brucella DNA can be sensed by TLR9 on endosomal membrane and by cytosolic AIM2-inflammasome to induce proinflammatory cytokine production that contributes to partially activate innate immunity. Additionally, Brucella DNA has been identified to be able to act as a major bacterial component to induce type I IFN. However, the role of Brucella DNA in Brucella intracellular growth remains unknown. Here, we showed that stimulation with Brucella DNA promote macrophage activation in TLR9-dependent manner. Activated macrophages can suppresses wild type Brucella intracellular replication at early stage of infection via enhancing NO production. We also reported that activated macrophage promotes bactericidal function of macrophages infected with VirB-deficient Brucella at the early or late stage of infection. This study uncovers a novel function of Brucella DNA, which can help us further elucidate the mechanism of Brucella intracellular survival. Copyright © 2015 Elsevier Ltd. All rights reserved.

Considerations for the rational design of a Chlamydia vaccine

OpenAIRE

Liang, Steven; Bulir, David; Kaushic, Charu; Mahony, James

2016-01-01

ABSTRACT Chlamydia trachomatis is the leading cause of preventable blindness and the most common bacterial sexually transmitted infection. Remarkable progress in vaccine research over the past six?decades has led to the advancement of novel C. trachomatis vaccine candidates into clinical trials. However, many questions regarding the role of specific cellular populations and molecular mechanisms in protective immunity against human C. trachomatis genital tract infections remain unanswered. Bio...

Is screening for chlamydia and gonorrhea in men who have sex with men associated with reduction of the prevalence of these infections? A systematic review of observational studies.

Science.gov (United States)

Tsoumanis, Achilleas; Hens, Niel; Kenyon, Chris Richard

2018-02-26

Neisseria gonorrhoeae (gonorrhea) could become untreatable in the near future. Indeed, while the treatment of symptomatic gonorrhea in core groups, such men who have sex with men (MSM), is crucial for gonorrhea control programs, screening for and treating asymptomatic gonorrhea/Chlamydia trachomatis(chlamydia) in MSM may contribute to antibiotic resistance in gonorrhea. In this systematic review we aim to assess if there is evidence that screening MSM for gonorrhea/chlamydia is associated with a decline in the prevalence of these infections. We conducted a systematic review in PubMed and Web of Science for relevant studies including uncontrolled observational studies and reported the results following the PRISMA guidelines. The change in estimated prevalences for chlamydia and gonorrhea across the different time points for three anatomical sites (oral, urethral and anal) were collected and examined. Twelve studies met our entry criteria. We were able to statistically assess the change in prevalence in 10 out of 12 studies. In three studies, there was a significant increase in chlamydia prevalence, while for gonorrhea two studies reported a significant increase and two others a decrease. Our review provides little evidence that screening for gonorrhea and chlamydia in MSM has an effect on the prevalence of these infections. No evidence was found that more frequent screening reduces prevalence more effectively than annual screening. Our study was not able to provide evidence that screening for chlamydia and gonorrhea lowers the prevalence of these infections in MSM. Randomized controlled trials are required to assess the risks and benefits of gonorrhea/chlamydia screening in high and low risk MSM.

IFN-gamma-inducible Irga6 mediates host resistance against Chlamydia trachomatis via autophagy.

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Munir A Al-Zeer

Full Text Available Chlamydial infection of the host cell induces Gamma interferon (IFNgamma, a central immunoprotector for humans and mice. The primary defense against Chlamydia infection in the mouse involves the IFNgamma-inducible family of IRG proteins; however, the precise mechanisms mediating the pathogen's elimination are unknown. In this study, we identify Irga6 as an important resistance factor against C. trachomatis, but not C. muridarum, infection in IFNgamma-stimulated mouse embryonic fibroblasts (MEFs. We show that Irga6, Irgd, Irgm2 and Irgm3 accumulate at bacterial inclusions in MEFs upon stimulation with IFNgamma, whereas Irgb6 colocalized in the presence or absence of the cytokine. This accumulation triggers a rerouting of bacterial inclusions to autophagosomes that subsequently fuse to lysosomes for elimination. Autophagy-deficient Atg5-/- MEFs and lysosomal acidification impaired cells surrender to infection. Irgm2, Irgm3 and Irgd still localize to inclusions in IFNgamma-induced Atg5-/- cells, but Irga6 localization is disrupted indicating its pivotal role in pathogen resistance. Irga6-deficient (Irga6-/- MEFs, in which chlamydial growth is enhanced, do not respond to IFNgamma even though Irgb6, Irgd, Irgm2 and Irgm3 still localize to inclusions. Taken together, we identify Irga6 as a necessary factor in conferring host resistance by remodelling a classically nonfusogenic intracellular pathogen to stimulate fusion with autophagosomes, thereby rerouting the intruder to the lysosomal compartment for destruction.

Frequency of Chlamydia trachomatis among male patients with urethritis in northeast of Iran detected by polymerase chain reaction

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Kiarash Ghazvini

2012-01-01

Full Text Available Planning for appropriate preventive measures against Chlamydia trachomatis, a common cause of sexually transmitted disease, requires knowledge of prevalence of infection so that interventions can be targeted in a cost-effective manner. This study was performed on 178 male patients presenting with urethritis in the Mashhad province to determine the prevalence of chlamydial infection in Northeast Iran. A cotton swab and first voided urine specimen were collected according to standard procedures. Polymerase chain reaction (PCR tests were used for the detection of C. trachomatis in the specimens collected and the results were analyzed using SPSS program. Results showed that 10.6% of male patients in this group were infected with C. trachomatis. This study provides strong evidence that prevalence of Chlamydia in the Northeast Iran is high and suggests that Chlamydia screening as a routine part of STD investigations is highly necessary in this area.

Effects of screening and partner notification on Chlamydia positivity in the United States: a modeling study.

Science.gov (United States)

Kretzschmar, Mirjam; Satterwhite, Catherine; Leichliter, Jami; Berman, Stuart

2012-05-01

Model impact of increasing screening and partner notification (PN) on chlamydia positivity. We used a stochastic simulation model describing pair formation and dissolution in an age-structured heterosexual population. The model accounts for steady, casual, and concurrent partnerships and a highly sexually active core group. The model used existing sexual behavior data from the United States and was validated using chlamydia positivity data from Region X (Alaska, Idaho, Oregon, Washington). A screening program with a coverage rate of 20% was implemented among women aged 15 to 24 years. After 10 years, we increased screening coverage to 35%, 50%, and 65% and partner treatment rates from 20% to 40% and 55%. Finally, we included male screening (aged 15-24, screening coverage: 20% and 35%, partner treatment: 25% and 40%). We analyzed the effects on chlamydia positivity in women and the frequency of reinfection 6 months after treatment. The model described the decline in positivity observed from 1988 to 1997 in Region X, given screening coverage of 20% and a 25% partner treatment rate. Increasing screening coverage from 35% to 65% resulted in incremental decreases in positivity as did increasing the PN rate; a 23% reduction in positivity was achieved by either increasing screening by 3-fold or PN by 2-fold. Adding male screening to the program had less impact than increasing screening coverage or PN among women. Increased PN and treatment reduced reinfection rates considerably. Increasing efforts in PN may contribute at least as much to control of chlamydia infection as increasing screening coverage rates.

Get Tested Why Not? A novel approach to internet-based chlamydia and gonorrhea testing in Canada.

Science.gov (United States)

Mann, Tara A; Uddin, Zhaida; Hendriks, Andrew M; Bouchard, Christiane J; Etches, Vera G

2013-03-07

The objective of the Get Tested Why Not campaign is to increase access to chlamydia and gonorrhea testing and sexual health information, with specific focus on youth. Individuals between the ages of 15-29 are most affected by chlamydia and gonorrhea infections in Ottawa and were identified as the target population. Youth from the target population were engaged in the development and launch of the campaign. Development of the campaign began in 2009 and led to a launch on March 21, 2011. Social media promotion as well as traditional advertising approaches developed awareness of the campaign within the target population. The campaign consists of a bilingual, youth-friendly website and texting service. After assessing appropriateness of testing, clients can download a requisition form for urine-based chlamydia and gonorrhea testing and submit a sample at one of 26 laboratories across Ottawa. During year 1 of the campaign, there were 13,385 website hits and 104 specimens submitted for chlamydia and gonorrhea testing. The majority (57.6%, n=60) of requisitions were submitted by members of the target population (age 15-29). Of the requisitions submitted, 95 (91.3%) were negative, 4 (3.9%) were positive and 5 (4.8%) were cancelled due to lab errors. The campaign is reaching the target population and has demonstrated a positive impact on knowledge and intended behaviours of users. The use of technology has expanded testing options, thereby potentially broadening Ottawa Public Health's reach to clients who may be less likely to test through traditional testing approaches.

Analysis of proteins in Chlamydia trachomatis L2 outer membrane complex, COMC

DEFF Research Database (Denmark)

Birkelund, Svend; Morgan-Fisher, Marie; Timmerman, Evy

2009-01-01

The protein composition and N-terminal sequences of proteins in the outer membrane of Chlamydia trachomatis L2 were analysed following isolation of N-terminal peptides using combined fractional diagonal chromatography and identification by liquid chromatography tandem MS. Acetylation of primary a...

Direct and indirect effects of screening for Chlamydia trachomatis on the prevention of pelvic inflammatory disease: a mathematical modeling study.

Science.gov (United States)

Herzog, Sereina A; Heijne, Janneke C M; Scott, Pippa; Althaus, Christian L; Low, Nicola

2013-11-01

Pelvic inflammatory disease (PID) results from the ascending spread of microorganisms, including Chlamydia trachomatis, to the upper genital tract. Screening could improve outcomes by identifying and treating chlamydial infections before they progress to PID (direct effect) or by reducing chlamydia transmission (indirect effect). We developed a compartmental model that represents a hypothetical heterosexual population and explicitly incorporates progression from chlamydia to clinical PID. Chlamydia screening was introduced, with coverage increasing each year for 10 years. We estimated the separate contributions of the direct and indirect effects of screening on PID cases prevented per 100,000 women. We explored the influence of varying the time point at which clinical PID could occur and of increasing the risk of PID after repeated chlamydial infections. The probability of PID at baseline was 3.1% by age 25 years. After 5 years, the intervention scenario had prevented 187 PID cases per 100,000 women and after 10 years 956 PID cases per 100,000 women. At the start of screening, most PID cases were prevented by the direct effect. The indirect effect produced a small net increase in PID cases, which was outweighed by the effect of reduced chlamydia transmission after 2.2 years. The later that progression to PID occurs, the greater the contribution of the direct effect. Increasing the risk of PID with repeated chlamydial infection increases the number of PID cases prevented by screening. This study shows the separate roles of direct and indirect PID prevention and potential harms, which cannot be demonstrated in observational studies.

Intracellular Bacterial Infections: A Challenge for Developing Cellular Mediated Immunity Vaccines for Farmed Fish

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Hetron Mweemba Munang’andu

2018-04-01

Full Text Available Aquaculture is one of the most rapidly expanding farming systems in the world. Its rapid expansion has brought with it several pathogens infecting different fish species. As a result, there has been a corresponding expansion in vaccine development to cope with the increasing number of infectious diseases in aquaculture. The success of vaccine development for bacterial diseases in aquaculture is largely attributed to empirical vaccine designs based on inactivation of whole cell (WCI bacteria vaccines. However, an upcoming challenge in vaccine design is the increase of intracellular bacterial pathogens that are not responsive to WCI vaccines. Intracellular bacterial vaccines evoke cellular mediated immune (CMI responses that “kill” and eliminate infected cells, unlike WCI vaccines that induce humoral immune responses whose protective mechanism is neutralization of extracellular replicating pathogens by antibodies. In this synopsis, I provide an overview of the intracellular bacterial pathogens infecting different fish species in aquaculture, outlining their mechanisms of invasion, replication, and survival intracellularly based on existing data. I also bring into perspective the current state of CMI understanding in fish together with its potential application in vaccine development. Further, I highlight the immunological pitfalls that have derailed our ability to produce protective vaccines against intracellular pathogens for finfish. Overall, the synopsis put forth herein advocates for a shift in vaccine design to include CMI-based vaccines against intracellular pathogens currently adversely affecting the aquaculture industry.

Construction of physical and genetic maps of Chlamydia trachomatis serovar L2 by pulsed-field gel electrophoresis

DEFF Research Database (Denmark)

Birkelund, Svend; Stephens, RS

1992-01-01

We constructed the physical map of Chlamydia trachomatis serovar L2 by using three restriction endonucleases, NotI (GC[GGCCGC), SgrAI (C(A/G)[CCGG(T/G)G), and Sse8387I (CCTGCA[GG), and we analyzed the fragments by pulsed-field gel electrophoresis. A total of 25 restriction endonuclease sites and 13...... genes and/or operons were located on the map. The genome size was determined to be 1,045 kb. Neither highly transcribed chlamydia genes nor developmental cycle-specific genes were clustered on the genome....

Isolation of chlamydia in irradiated and non-irradiated McCoy cells

International Nuclear Information System (INIS)

Johnson, L.; Harper, I.A.

1975-01-01

Specimens from eye and genital tract were cultured in parallel in irradiated and non-irradiated McCoy cells and the frequency of isolation of chlamydia using these culture methods was compared. There was a significant difference between the frequencies of isolation; irradiated McCoy cells produced a greater number of positive results. (author)

Novel overlapping coding sequences in Chlamydia trachomatis

DEFF Research Database (Denmark)

Jensen, Klaus Thorleif; Petersen, Lise; Falk, Søren

2006-01-01

that are in agreement with the primary annotation. Forty two genes from the primary annotation are not predicted by EasyGene. The majority of these genes are listed as hypothetical in the primary annotation. The 15 novel predicted genes all overlap with genes on the complementary strand. We find homologues of several...... of the novel genes in C. trachomatis Serovar A and Chlamydia muridarum. Several of the genes have typical gene-like and protein-like features. Furthermore, we confirm transcriptional activity from 10 of the putative genes. The combined evidence suggests that at least seven of the 15 are protein coding genes...

Translation inhibition of the developmental cycle protein HctA by the small RNA IhtA is conserved across Chlamydia.

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Jeremiah Tattersall

Full Text Available The developmental cycle of the obligate intracellular pathogen Chlamydia trachomatis serovar L2 is controlled in part by the small non-coding RNA (sRNA, IhtA. All Chlamydia alternate in a regulated fashion between the infectious elementary body (EB and the replicative reticulate body (RB which asynchronously re-differentiates back to the terminal EB form at the end of the cycle. The histone like protein HctA is central to RB:EB differentiation late in the cycle as it binds to and occludes the genome, thereby repressing transcription and translation. The sRNA IhtA is a critical component of this regulatory loop as it represses translation of hctA until late in infection at which point IhtA transcription decreases, allowing HctA expression to occur and RB to EB differentiation to proceed. It has been reported that IhtA is expressed during infection by the human pathogens C. trachomatis serovars L2, D and L2b and C. pneumoniae. We show in this work that IhtA is also expressed by the animal pathogens C. caviae and C. muridarum. Expression of HctA in E. coli is lethal and co-expression of IhtA relieves this phenotype. To determine if regulation of HctA by IhtA is a conserved mechanism across pathogenic chlamydial species, we cloned hctA and ihtA from C. trachomatis serovar D, C. muridarum, C. caviae and C. pneumoniae and assayed for rescue of growth repression in E. coli co-expression studies. In each case, co-expression of ihtA with the cognate hctA resulted in relief of growth repression. In addition, expression of each chlamydial species IhtA rescued the lethal phenotype of C. trachomatis serovar L2 HctA expression. As biolayer interferometry studies indicate that IhtA interacts directly with hctA message for all species tested, we predict that conserved sequences of IhtA are necessary for function and/or binding.

Chlamydia trachomatis In Vivo to In Vitro Transition Reveals Mechanisms of Phase Variation and Down-Regulation of Virulence Factors.

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Vítor Borges

Full Text Available Research on the obligate intracellular bacterium Chlamydia trachomatis demands culture in cell-lines, but the adaptive process behind the in vivo to in vitro transition is not understood. We assessed the genomic and transcriptomic dynamics underlying C. trachomatis in vitro adaptation of strains representing the three disease groups (ocular, epithelial-genital and lymphogranuloma venereum propagated in epithelial cells over multiple passages. We found genetic features potentially underlying phase variation mechanisms mediating the regulation of a lipid A biosynthesis enzyme (CT533/LpxC, and the functionality of the cytotoxin (CT166 through an ON/OFF mechanism. We detected inactivating mutations in CT713/porB, a scenario suggesting metabolic adaptation to the available carbon source. CT135 was inactivated in a tropism-specific manner, with CT135-negative clones emerging for all epithelial-genital populations (but not for LGV and ocular populations and rapidly increasing in frequency (~23% mutants per 10 passages. RNA-sequencing analyses revealed that a deletion event involving CT135 impacted the expression of multiple virulence factors, namely effectors known to play a role in the C. trachomatis host-cell invasion or subversion (e.g., CT456/Tarp, CT694, CT875/TepP and CT868/ChlaDub1. This reflects a scenario of attenuation of C. trachomatis virulence in vitro, which may take place independently or in a cumulative fashion with the also observed down-regulation of plasmid-related virulence factors. This issue may be relevant on behalf of the recent advances in Chlamydia mutagenesis and transformation where culture propagation for selecting mutants/transformants is mandatory. Finally, there was an increase in the growth rate for all strains, reflecting gradual fitness enhancement over time. In general, these data shed light on the adaptive process underlying the C. trachomatis in vivo to in vitro transition, and indicates that it would be prudent to

Translation inhibition of the developmental cycle protein HctA by the small RNA IhtA is conserved across Chlamydia.

Science.gov (United States)

Tattersall, Jeremiah; Rao, Geeta Vittal; Runac, Justin; Hackstadt, Ted; Grieshaber, Scott S; Grieshaber, Nicole A

2012-01-01

The developmental cycle of the obligate intracellular pathogen Chlamydia trachomatis serovar L2 is controlled in part by the small non-coding RNA (sRNA), IhtA. All Chlamydia alternate in a regulated fashion between the infectious elementary body (EB) and the replicative reticulate body (RB) which asynchronously re-differentiates back to the terminal EB form at the end of the cycle. The histone like protein HctA is central to RB:EB differentiation late in the cycle as it binds to and occludes the genome, thereby repressing transcription and translation. The sRNA IhtA is a critical component of this regulatory loop as it represses translation of hctA until late in infection at which point IhtA transcription decreases, allowing HctA expression to occur and RB to EB differentiation to proceed. It has been reported that IhtA is expressed during infection by the human pathogens C. trachomatis serovars L2, D and L2b and C. pneumoniae. We show in this work that IhtA is also expressed by the animal pathogens C. caviae and C. muridarum. Expression of HctA in E. coli is lethal and co-expression of IhtA relieves this phenotype. To determine if regulation of HctA by IhtA is a conserved mechanism across pathogenic chlamydial species, we cloned hctA and ihtA from C. trachomatis serovar D, C. muridarum, C. caviae and C. pneumoniae and assayed for rescue of growth repression in E. coli co-expression studies. In each case, co-expression of ihtA with the cognate hctA resulted in relief of growth repression. In addition, expression of each chlamydial species IhtA rescued the lethal phenotype of C. trachomatis serovar L2 HctA expression. As biolayer interferometry studies indicate that IhtA interacts directly with hctA message for all species tested, we predict that conserved sequences of IhtA are necessary for function and/or binding.

Radiobilogical cell survival models

International Nuclear Information System (INIS)

Zackrisson, B.

1992-01-01

A central issue in clinical radiobiological research is the prediction of responses to different radiation qualities. The choice of cell survival and dose-response model greatly influences the results. In this context the relationship between theory and model is emphasized. Generally, the interpretations of experimental data depend on the model. Cell survival models are systematized with respect to their relations to radiobiological theories of cell kill. The growing knowlegde of biological, physical, and chemical mechanisms is reflected in the formulation of new models. The present overview shows that recent modelling has been more oriented towards the stochastic fluctuations connected to radiation energy deposition. This implies that the traditional cell surivival models ought to be complemented by models of stochastic energy deposition processes and repair processes at the intracellular level. (orig.)

Short-Term and Long-Term Survival and Virulence of Legionella pneumophila in the Defined Freshwater Medium Fraquil.

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Nilmini Mendis

Full Text Available Legionella pneumophila (Lp is the etiological agent responsible for Legionnaires' disease, a potentially fatal pulmonary infection. Lp lives and multiplies inside protozoa in a variety of natural and man-made water systems prior to human infection. Fraquil, a defined freshwater medium, was used as a highly reproducible medium to study the behaviour of Lp in water. Adopting a reductionist approach, Fraquil was used to study the impact of temperature, pH and trace metal levels on the survival and subsequent intracellular multiplication of Lp in Acanthamoeba castellanii, a freshwater protozoan and a natural host of Legionella. We show that temperature has a significant impact on the short- and long-term survival of Lp, but that the bacterium retains intracellular multiplication potential for over six months in Fraquil. Moreover, incubation in Fraquil at pH 4.0 resulted in a rapid decline in colony forming units, but was not detrimental to intracellular multiplication. In contrast, variations in trace metal concentrations had no impact on either survival or intracellular multiplication in amoeba. Our data show that Lp is a resilient bacterium in the water environment, remaining infectious to host cells after six months under the nutrient-deprived conditions of Fraquil.

Induction of cell-mediated immunity during early stages of infection with intracellular protozoa

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Gazzinelli R.T.

1998-01-01

Full Text Available Toxoplasma gondii and Trypanosoma cruzi are intracellular parasites which, as part of their life cycle, induce a potent cell-mediated immunity (CMI maintained by Th1 lymphocytes and IFN-g. In both cases, induction of a strong CMI is thought to protect the host against rapid parasite multiplication and consequent pathology and lethality during the acute phase of infection. However, the parasitic infection is not eliminated by the immune system and the vertebrate host serves as a parasite reservoir. In contrast, Leishmania sp, which is a slow growing parasite, appears to evade induction of CMI during early stages of infection as a strategy for surviving in a hostile environment (i.e., inside the macrophages which are their obligatory niche in the vertebrate host. Recent reports show that the initiation of IL-12 synthesis by macrophages during these parasitic infections is a key event in regulating CMI and disease outcome. The studies reviewed here indicate that activation/inhibition of distinct signaling pathways and certain macrophage functions by intracellular protozoa are important events in inducing/modulating the immune response of their vertebrate hosts, allowing parasite and host survival and therefore maintaining parasite life cycles.

Typing Chlamydia trachomatis: from egg yolk to nanotechnology

DEFF Research Database (Denmark)

Pedersen, Lisbeth Nørum; Herrmann, Bjørn; Møller, Jens Kjølseth

2009-01-01

A historical review is provided of the various methods used for half a century to differentiate and type Chlamydia trachomatis strains. Typing of C. trachomatis is an important tool for revealing transmission patterns in sexual networks, and enabling association with clinical manifestations......, insufficient epidemiological resolution is achieved by characterization of both MOMP and omp1. This calls for new high-resolution genotyping methods applying for example a multilocus variable number tandem repeat assay (MLVA) or multilocus sequence typing (MLST). The futuristic nanotechnology already seems...

Frequency of Chlamydia trachomatis in genital specimens: kerman city, PCR method

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Khalili M

2008-06-01

Full Text Available Background: Chlamydia trachomatis (CT is an obligate intracellular bacterium that causes genital disease and the most common sexually transmitted infection in the world. The most frequent risk factors associated with chlamydial infection are related to sexual behavior, multiple partners, and inconsistent condom use. Presenting primarily as urtheritis in men and cervicitis in women, CT a major cause of chronic pelvic inflammatory disease and subsequent infertility in women, eye and lung infection in newborns and other manifestations. Identification of CT-infected patients may prevent its spread and thereby reduce the high morbidity associated with CT infections. Polymerase chain reaction (PCR is a sensitive and specific method for the detection of small quantity of bacterial DNA in clinical samples. The aim of this study was to determine the frequency of C. trachomatis by PCR in genital samples from patients in the city of Kerman.Methods: A total of 130 genital samples including 64 endocervical and 66 urethral swab samples were collected by physicians. Nucleic acid was extracted from each sample using a commercial DNA extraction kit. PCR primers specific for a conserved region of the C. trachomatis omp2 gene, encoding an outer membrane protein, were used for amplification.  Results: A total of 9.2% (6.25% of cervicitis and 12.1% of urethritis of the samples were found positive for CT using this PCR method. Conclusions:  The present study shows a high prevalence of CT infection, especially in men with urethritis. Such patients should be referred to genitourinary clinics for treatment and partner notification. Given its worldwide prevalence, further CT studies on more populations are needed to assess potential public health implications of these infections.

Chlamydia related bacteria (Chlamydiales) in early pregnancy: community-based cohort study.

Science.gov (United States)

Reid, F; Oakeshott, P; Kerry, S R; Hay, P E; Jensen, J S

2017-02-01

Serological case-control studies suggest that certain chlamydia-related bacteria (Chlamydiales) which cause cows to abort may do the same in humans. Chlamydiales include Waddlia chondrophila, Chlamydia abortus and Chlamydia trachomatis. Data on prevalence of Chlamydiales in pregnancy are sparse. Using stored urine samples from a carefully characterised cohort of 847 newly pregnant women recruited from 37 general practices in London, UK, we aimed to investigate the prevalence and types of Chlamydiales infections. We also explored possible associations with miscarriage or spontaneous preterm birth. Samples were tested using W. chondrophila and pan-Chlamydiales specific real-time PCRs targeting the 16S rRNA gene. Samples positive on either PCR were subjected to DNA sequencing and C. trachomatis PCR. The overall prevalence of Chlamydiales was 4.3% (36/847, 95% CI 3.0% to 5.8%). The prevalence of W. chondrophila was 0.6% (n = 5), C. trachomatis 1.7% (n = 14), and other Chlamydiales species 2.0% (n = 17). Infection with C. trachomatis was more common in women aged <25, of black ethnicity or with bacterial vaginosis, but this did not apply to W. chondrophila or other Chlamydiales. Follow up was 99.9% at 16 weeks gestation and 90% at term. No infection was significantly associated with miscarriage at ≤12 weeks (prevalence 10%, 81/827) or preterm birth <37 weeks (prevalence 4%, 23/628). Of 25 samples sequenced, seven (28%) were positive for Chlamydiales bacterium sequences associated with respiratory tract infections in children. In the first study to use the pan-Chlamydiales assay on female urine samples, 4% of pregnant women tested positive for Chlamydiales, including species known to be pathogenic in mothers and neonates. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

The Chlamydia type III secretion system C-ring engages a chaperone-effector protein complex.

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Kris E Spaeth

2009-09-01

Full Text Available In Gram-negative bacterial pathogens, specialized chaperones bind to secreted effector proteins and maintain them in a partially unfolded form competent for translocation by type III secretion systems/injectisomes. How diverse sets of effector-chaperone complexes are recognized by injectisomes is unclear. Here we describe a new mechanism of effector-chaperone recognition by the Chlamydia injectisome, a unique and ancestral line of these evolutionarily conserved secretion systems. By yeast two-hybrid analysis we identified networks of Chlamydia-specific proteins that interacted with the basal structure of the injectisome, including two hubs of protein-protein interactions that linked known secreted effector proteins to CdsQ, the putative cytoplasmic C-ring component of the secretion apparatus. One of these protein-interaction hubs is defined by Ct260/Mcsc (Multiple cargo secretion chaperone. Mcsc binds to and stabilizes at least two secreted hydrophobic proteins, Cap1 and Ct618, that localize to the membrane of the pathogenic vacuole ("inclusion". The resulting complexes bind to CdsQ, suggesting that in Chlamydia, the C-ring of the injectisome mediates the recognition of a subset of inclusion membrane proteins in complex with their chaperone. The selective recognition of inclusion membrane proteins by chaperones may provide a mechanism to co-ordinate the translocation of subsets of inclusion membrane proteins at different stages in infection.

Costs and cost effectiveness of different strategies for chlamydia screening and partner notification: an economic and mathematical modelling study.

Science.gov (United States)

Turner, Katy; Adams, Elisabeth; Grant, Arabella; Macleod, John; Bell, Gill; Clarke, Jan; Horner, Paddy

2011-01-04

To compare the cost, cost effectiveness, and sex equity of different intervention strategies within the English National Chlamydia Screening Programme. To develop a tool for calculating cost effectiveness of chlamydia control programmes at a local, national, or international level. An economic and mathematical modelling study with cost effectiveness analysis. Costs were restricted to those of screening and partner notification from the perspective of the NHS and excluded patient costs, the costs of reinfection, and costs of complications arising from initial infection. England. Population Individuals eligible for the National Chlamydia Screening Programme. Cost effectiveness of National Chlamydia Screening Programme in 2008-9 (as cost per individual tested, cost per positive diagnosis, total cost of screening, number screened, number infected, sex ratio of those tested and treated). Comparison of baseline programme with two different interventions-(i) increased coverage of primary screening in men and (ii) increased efficacy of partner notification. In 2008-9 screening was estimated to cost about £46.3m in total and £506 per infection treated. Provision for partner notification within the screening programme cost between £9 and £27 per index case, excluding treatment and testing. The model results suggest that increasing male screening coverage from 8% (baseline value) to 24% (to match female coverage) would cost an extra £22.9m and increase the cost per infection treated to £528. In contrast, increasing partner notification efficacy from 0.4 (baseline value) to 0.8 partners per index case would cost an extra £3.3m and would reduce the cost per infection diagnosed to £449. Increasing screening coverage to 24% in men would cost over six times as much as increasing partner notification to 0.8 but only treat twice as many additional infections. In the English National Chlamydia Screening Programme increasing the effectiveness of partner notification is likely

CORRELATIONS BETWEEN CONTEMPORARY METHODS IN THE DIAGNOSIS OF CHLAMYDIA TRACHOMATIS UROGENITAL INFECTIONS.

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Ilko Bakardzhiev

2011-10-01

Full Text Available The subject of this study were 486 outpatients between the ages of 17 and 62, diagnosed with urethritis, epidydimitis, prostatitis, cervicitis, endocervicitis, pelvic inflammatory disease and sterility. The following tests were used to make the diagnosis of Chlamydia trachomatis: Enzyme Immunoassay (EIA, Enzyme-Linked Fluorescent Assay (ELFA, Polymerase Chain Reaction DNA amplification for Chlamydia Trachomatis, Neisseria Gonorrhoeae, Mycoplasma Genitalium and Ureaplasma Urealyiticum. Comparison PCR and EIA showed statistically significant difference between the positive results obtained by the two methods (p0,1. EIA is a method that gives a higher percentage of nonspecific positive reactions, while the results obtained from ELFA are much closer to the ones obtained by PCR. According to contemporary evidence based medicine, the developmet of unified standard methods for diagnosis and evaluation is of vital importance, not only for the patient and the treating physician but also concerns for the healthcare system, the general public and the pharmaceutical companies as well.

An antimicrobial peptide essential for bacterial survival in the nitrogen-fixing symbiosis.

Science.gov (United States)

Kim, Minsoo; Chen, Yuhui; Xi, Jiejun; Waters, Christopher; Chen, Rujin; Wang, Dong

2015-12-08

In the nitrogen-fixing symbiosis between legume hosts and rhizobia, the bacteria are engulfed by a plant cell membrane to become intracellular organelles. In the model legume Medicago truncatula, internalization and differentiation of Sinorhizobium (also known as Ensifer) meliloti is a prerequisite for nitrogen fixation. The host mechanisms that ensure the long-term survival of differentiating intracellular bacteria (bacteroids) in this unusual association are unclear. The M. truncatula defective nitrogen fixation4 (dnf4) mutant is unable to form a productive symbiosis, even though late symbiotic marker genes are expressed in mutant nodules. We discovered that in the dnf4 mutant, bacteroids can apparently differentiate, but they fail to persist within host cells in the process. We found that the DNF4 gene encodes NCR211, a member of the family of nodule-specific cysteine-rich (NCR) peptides. The phenotype of dnf4 suggests that NCR211 acts to promote the intracellular survival of differentiating bacteroids. The greatest expression of DNF4 was observed in the nodule interzone II-III, where bacteroids undergo differentiation. A translational fusion of DNF4 with GFP localizes to the peribacteroid space, and synthetic NCR211 prevents free-living S. meliloti from forming colonies, in contrast to mock controls, suggesting that DNF4 may interact with bacteroids directly or indirectly for its function. Our findings indicate that a successful symbiosis requires host effectors that not only induce bacterial differentiation, but also that maintain intracellular bacteroids during the host-symbiont interaction. The discovery of NCR211 peptides that maintain bacterial survival inside host cells has important implications for improving legume crops.

Estrogen-induced disruption of intracellular iron metabolism leads to oxidative stress, membrane damage, and cell cycle arrest in MCF-7 cells.

Science.gov (United States)

Bajbouj, Khuloud; Shafarin, Jasmin; Abdalla, Maher Y; Ahmad, Iman M; Hamad, Mawieh

2017-10-01

It is well established that several forms of cancer associate with significant iron overload. Recent studies have suggested that estrogen (E2) disrupts intracellular iron homeostasis by reducing hepcidin synthesis and maintaining ferroportin integrity. Here, the ability of E2 to alter intracellular iron status and cell growth potential was investigated in MCF-7 cells treated with increasing concentrations of E2. Treated cells were assessed for intracellular iron status, the expression of key proteins involved in iron metabolism, oxidative stress, cell survival, growth, and apoptosis. E2 treatment resulted in a significant reduction in hepcidin expression and a significant increase in hypoxia-inducible factor 1 alpha, ferroportin, transferrin receptor, and ferritin expression; a transient decrease in labile iron pool; and a significant increase in total intracellular iron content mainly at 20 nM/48 h E2 dose. Treated cells also showed increased total glutathione and oxidized glutathione levels, increased superoxide dismutase activity, and increased hemoxygenase 1 expression. Treatment with E2 at 20 nM for 48 h resulted in a significant reduction in cell growth (0.35/1 migration rate) and decreased cell survival (iron metabolism and precipitates adverse effects concerning cell viability, membrane integrity, and growth potential.

Efficacy of interventions to increase the uptake of chlamydia screening in primary care: a systematic review

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Donovan Basil

2011-08-01

Full Text Available Abstract Background As most genital chlamydia infections are asymptomatic, screening is the main way to detect and cases for treatment. We undertook a systematic review of studies assessing the efficacy of interventions for increasing the uptake of chlamydia screening in primary care. Methods We reviewed studies which compared chlamydia screening in the presence and the absence of an intervention. The primary endpoints were screening rate or total tests. Results We identified 16 intervention strategies; 11 were randomised controlled trials and five observational studies, 10 targeted females only, five both males and females, and one males only. Of the 15 interventions among females, six were associated with significant increases in screening rates at the 0.05 level including a multifaceted quality improvement program that involved provision of a urine jar to patients at registration (44% in intervention clinics vs. 16% in the control clinic; linking screening to routine Pap smears (6.9% vs. 4.5%, computer alerts for doctors (12.2% vs. 10.6%; education workshops for clinic staff; internet-based continuing medical education (15.5% vs. 12.4%; and free sexual health consultations (16.8% vs. 13.2%. Of the six interventions targeting males, two found significant increases including the multifaceted quality improvement program in which urine jars were provided to patients at registration (45% vs. 15%; and the offering by doctors of a test to all presenting young male clients, prior to consultation (29 vs. 4%. Conclusions Interventions that promoted the universal offer of a chlamydia test in young people had the greatest impact on increasing screening in primary care.

Chlamydia trachomatis and chlamydial heat shock protein 60-specific antibody and cell-mediated responses predict tubal factor infertility

DEFF Research Database (Denmark)

Tiitinen, A.; Surcel, H.-M.; Halttunen, M.

2006-01-01

60)-specific immunoglobulin G (IgG) antibodies were analysed using enzyme-linked immunosorbent assay (ELISA) kits. Proliferative reactivity of peripheral blood mononuclear cells was studied in vitro against Chlamydia elementary body (EB) and recombinant CHSP60 antigens. RESULTS: C. trachomatis......BACKGROUND: To evaluate the role of Chlamydia trachomatis-induced humoral and cell-mediated immune (CMI) responses in predicting tubal factor infertility (TFI). METHODS: Blood samples were taken from 88 women with TFI and 163 control women. C. trachomatis and chlamydial heat shock protein 60 (CHSP...

An online study combining the constructs from the theory of planned behaviour and protection motivation theory in predicting intention to test for chlamydia in two testing contexts

OpenAIRE

Powell, R. L.; Pattison, H. M.; Francis, J.

2016-01-01

Chlamydia is a common sexually-transmitted infection that has potentially serious consequences unless detected and treated early. The health service in the UK offers clinic-based testing for chlamydia but uptake is low. Identifying the predictors of testing behaviours may inform interventions to increase uptake. Self-tests for chlamydia may facilitate testing and treatment in people who avoid clinic-based testing. Self-testing and being tested by a health care professional (HCP) involve two c...

Two coiled-coil domains of Chlamydia trachomatis IncA affect membrane fusion events during infection.

Science.gov (United States)

Ronzone, Erik; Paumet, Fabienne

2013-01-01

Chlamydia trachomatis replicates in a parasitophorous membrane-bound compartment called an inclusion. The inclusions corrupt host vesicle trafficking networks to avoid the degradative endolysosomal pathway but promote fusion with each other in order to sustain higher bacterial loads in a process known as homotypic fusion. The Chlamydia protein IncA (Inclusion protein A) appears to play central roles in both these processes as it participates to homotypic fusion and inhibits endocytic SNARE-mediated membrane fusion. How IncA selectively inhibits or activates membrane fusion remains poorly understood. In this study, we analyzed the spatial and molecular determinants of IncA's fusogenic and inhibitory functions. Using a cell-free membrane fusion assay, we found that inhibition of SNARE-mediated fusion requires IncA to be on the same membrane as the endocytic SNARE proteins. IncA displays two coiled-coil domains showing high homology with SNARE proteins. Domain swap and deletion experiments revealed that although both these domains are capable of independently inhibiting SNARE-mediated fusion, these two coiled-coil domains cooperate in mediating IncA multimerization and homotypic membrane interaction. Our results support the hypothesis that Chlamydia employs SNARE-like virulence factors that positively and negatively affect membrane fusion and promote infection.

Two coiled-coil domains of Chlamydia trachomatis IncA affect membrane fusion events during infection.

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Erik Ronzone

Full Text Available Chlamydia trachomatis replicates in a parasitophorous membrane-bound compartment called an inclusion. The inclusions corrupt host vesicle trafficking networks to avoid the degradative endolysosomal pathway but promote fusion with each other in order to sustain higher bacterial loads in a process known as homotypic fusion. The Chlamydia protein IncA (Inclusion protein A appears to play central roles in both these processes as it participates to homotypic fusion and inhibits endocytic SNARE-mediated membrane fusion. How IncA selectively inhibits or activates membrane fusion remains poorly understood. In this study, we analyzed the spatial and molecular determinants of IncA's fusogenic and inhibitory functions. Using a cell-free membrane fusion assay, we found that inhibition of SNARE-mediated fusion requires IncA to be on the same membrane as the endocytic SNARE proteins. IncA displays two coiled-coil domains showing high homology with SNARE proteins. Domain swap and deletion experiments revealed that although both these domains are capable of independently inhibiting SNARE-mediated fusion, these two coiled-coil domains cooperate in mediating IncA multimerization and homotypic membrane interaction. Our results support the hypothesis that Chlamydia employs SNARE-like virulence factors that positively and negatively affect membrane fusion and promote infection.

Chlamydia muridarum Alters the Immune Environment of the Murine Genital Tract to be More Permissive for Infection with Neisseria gonorrhoeae in a Novel Coinfection Model

Science.gov (United States)

2011-04-05

1 2.0 Gonorrhea and Chlamydia ........................................................................................ 2 2.1...39 4.1 Experimental Models of Gonorrhea ...acquisition of several STIs, including gonorrhea and chlamydia (82). Additionally, the signs and symptoms of these STIs are usually more common and

Trade-Offs of Escherichia coli Adaptation to an Intracellular Lifestyle in Macrophages.

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M Azevedo

Full Text Available The bacterium Escherichia coli exhibits remarkable genomic and phenotypic variation, with some pathogenic strains having evolved to survive and even replicate in the harsh intra-macrophage environment. The rate and effects of mutations that can cause pathoadaptation are key determinants of the pace at which E. coli can colonize such niches and become pathogenic. We used experimental evolution to determine the speed and evolutionary paths undertaken by a commensal strain of E. coli when adapting to intracellular life. We estimated the acquisition of pathoadaptive mutations at a rate of 10-6 per genome per generation, resulting in the fixation of more virulent strains in less than a hundred generations. Whole genome sequencing of independently evolved clones showed that the main targets of intracellular adaptation involved loss of function mutations in genes implicated in the assembly of the lipopolysaccharide core, iron metabolism and di- and tri-peptide transport, namely rfaI, fhuA and tppB, respectively. We found a substantial amount of antagonistic pleiotropy in evolved populations, as well as metabolic trade-offs, commonly found in intracellular bacteria with reduced genome sizes. Overall, the low levels of clonal interference detected indicate that the first steps of the transition of a commensal E. coli into intracellular pathogens are dominated by a few pathoadaptive mutations with very strong effects.

Meeting sexual partners online: associated sexual behaviour and prevalent chlamydia infection among adolescents in Norway: a cross-sectional study.

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Gravningen, Kirsten; Aicken, Catherine Rh; Schirmer, Henrik; Mercer, Catherine H

2016-03-01

Evidence is mixed as to whether meeting sexual partners online ('internet-partners') is associated with risky sexual behaviour and/or sexually transmitted infection transmission. Accordingly, we sought to estimate the prevalence of reporting various online romantic and sexual activities among Norwegian adolescents, including internet-partners, and the reason for meeting them and to examine differences in sexual behaviour, partnership characteristics and chlamydia infection prevalence among those reporting internet-partners versus those reporting only offline partners. Population-based cross-sectional survey among sexually experienced girls and boys, 15-20 years, using electronic questionnaires and collecting urine samples for Chlamydia trachomatis PCR testing (79% provided both, n=1023). We used logistic regression to examine associations, adjusting for potentially confounding variables. Overall, 30% of both genders reported internet-partners (ever). Boys (but not girls) with internet-partners had higher chlamydia prevalence than those reporting meeting sexual partners only offline (8.1%, 95% CI 4.3% to 13.7% vs 1.6%, 0.5% to 3.7%). Two-thirds of girls and 37% of boys reported meeting their most recent internet-partner to start a romantic relationship, while the remainder did so with the specific intention of having sex. Among both genders, reporting sexual (vs romantic) reasons for meeting their most recent internet-partners was associated with reporting several risky sexual behaviours, including multiple recent sex partners (adjusted OR girls: 3.27, boys: 2.48) and three-fold higher chlamydia prevalence. This population-based study suggests that internet-partners are common among adolescents in Norway, and the reason for meeting them was more strongly associated with additionally reporting sexual risk behaviours and prevalent chlamydia infection than the internet itself as a meeting venue. Published by the BMJ Publishing Group Limited. For permission to use

Interleukin-1 is the initiator of Fallopian tube destruction during Chlamydia trachomatis infection

DEFF Research Database (Denmark)

Hvid, Malene; Baczynska, Agata; Deleuran, Bent

2007-01-01

Chlamydia trachomatis infection is associated with severe Fallopian tube tissue damage leading to tubal infertility and ectopic pregnancy. To explore the molecular mechanisms behind infection an ex vivo model was established from human Fallopian tubes and examined by scanning electron microscopy...

Field evaluation of a new commercially available ELISA based on a recombinant antigen for diagnosing Chlamydophila abortus (Chlamydia psittaci serotype 1) infection.

Science.gov (United States)

Buendía, A J; Cuello, F; Del Rio, L; Gallego, M C; Caro, M R; Salinas, J

2001-02-12

A new commercially available ELISA (ELISAr-Chlamydia) for detecting antibodies against Chlamydophila abortus has been evaluated using sheep field serum samples. The ELISA is based on a recombinant antigen which expresses part of a protein from the 80-90kDa family that is specific to C. abortus. Sera (105) from six flocks with confirmed ovine chlamydial abortion (OEA) outbreaks were used in this study, as well as sera (258) from 18 flocks which had suffered no OEA in the last lambing. The ELISAr-Chlamydia was compared with the complement fixation test (CFT) and with an ELISA using purified C. abortus elementary bodies (ELISA-EB), employing as reference technique a comparative microimmunofluorescence test that differentiates C. abortus infection from Chlamydophila pecorum infection. The results showed that the sensitivity of ELISAr-Chlamydia was 90.9% with a specificity of 85.9%, the sensitivity of CFT was 71.0% with a specificity of 83.6%, while the sensitivity of ELISA-EB was 95.2% and the specificity was 54.2%. Furthermore, ELISAr-Chlamydia was the test with fewer false positives resulting from positive reactivity to C. pecorum, although 15% of the sera positive for C. pecorum but negative for C. abortus antibodies reacted positively. This study demonstrated with field material that ELISAr-Chlamydia provides the most balanced results between sensitivity and specificity, especially in flocks with no clinical OEA but reactivity to C. abortus.

Detection of PCR inhibitors in cervical specimens by using the AMPLICOR Chlamydia trachomatis assay

NARCIS (Netherlands)

R.P.A.J. Verkooyen (Roel); A. Luijendijk (Ad); W.M. Huisman; W.H.F. Goessens (Wil); J.A.J.W. Kluytmans (Jan); J.H. van Rijsoort-Vos; H.A. Verbrugh (Henri)

1996-01-01

textabstractTo determine that susceptibility of AMPLICOR Chlamydia trachomatis PCR to inhibitory factors possibly present in cervical specimens, we obtained cervical specimens from 200 gynecology patients attending our outpatient clinic. The prevalence of C. trachomatis

Chlamydia trachomatis and genital human papillomavirus infections in female university students in Honduras.

NARCIS (Netherlands)

Tabora, N.; Zelaya, A.; Bakkers, J.; Melchers, W.J.; Ferrera, A.

2005-01-01

Sexually transmitted infections are a serious health problem in Honduras. Human papillomavirus (HPV) and Chlamydia trachomatis are major causes of sexually transmitted diseases. To determine the prevalence of C. trachomatis and HPV in young women, 100 female university students in Honduras were

Rationale and design of REACT: a randomised controlled trial assessing the effectiveness of home-collection to increase chlamydia retesting and detect repeat positive tests.

Science.gov (United States)

Smith, Kirsty S; Hocking, Jane S; Chen, Marcus; Fairley, Christopher K; McNulty, Anna; Read, Phillip; Bradshaw, Catriona S; Tabrizi, Sepehr N; Wand, Handan; Saville, Marion; Rawlinson, William; Garland, Suzanne M; Donovan, Basil; Kaldor, John M; Guy, Rebecca

2014-04-24

Repeat infection with Chlamydia trachomatis is common and increases the risk of sequelae in women and HIV seroconversion in men who have sex with men (MSM). Despite guidelines recommending chlamydia retesting three months after treatment, retesting rates are low. We are conducting the first randomised controlled trial to assess the effectiveness of home collection combined with short message service (SMS) reminders on chlamydia retesting and reinfection rates in three risk groups. The REACT (retest after Chlamydia trachomatis) trial involves 600 patients diagnosed with chlamydia: 200 MSM, 200 women and 200 heterosexual men recruited from two Australian sexual health clinics where SMS reminders for retesting are routine practice. Participants will be randomised to the home group (3-month SMS reminder and home-collection) or the clinic group (3-month SMS reminder to return to the clinic). Participants in the home group will be given the choice of attending the clinic if they prefer. The mailed home-collection kit includes a self-collected vaginal swab (women), UriSWAB (Copan) for urine collection (heterosexual men), and UriSWAB plus rectal swab (MSM). The primary outcome is the retest rate at 1-4 months after a chlamydia diagnosis, and the secondary outcomes are: the repeat positive test rate; the reinfection rate; the acceptability of home testing with SMS reminders; and the cost effectiveness of home testing. Sexual behaviour data collected via an online survey at 4-5 months, and genotyping of repeat infections, will be used to discriminate reinfections from treatment failures. The trial will be conducted over two years. An intention to treat analysis will be conducted. This study will provide evidence about the effectiveness of home-collection combined with SMS reminders on chlamydia retesting, repeat infection and reinfection rates in three risk groups. The trial will determine client acceptability and cost effectiveness of this strategy. Australian and New

Activation of a Neospora caninum EGFR-Like Kinase Facilitates Intracellular Parasite Proliferation

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Xiaoxia Jin

2017-10-01

Full Text Available The Apicomplexan parasite Neospora caninum, an obligate intracellular protozoan, causes serious diseases in a number of mammalian species, especially in cattle. Infection with N. caninum is associated with abortions in both dairy and beef cattle worldwide which have a major economic impact on the cattle industry. However, the mechanism by which N. caninum proliferates within host cells is poorly understood. Epidermal growth factor receptor (EGFR is a protein kinase ubiquitously expressed, present on cell surfaces in numerous species, which has been confirmed to be essential in signal transduction involved in cell growth, proliferation, survival, and many other intracellular processes. However, the presence of EGFR in N. caninum and its role in N. caninum proliferation remain unclear. In the present study, we identified a putative EGFR-like kinase in N. caninum, which could be activated in tachyzoites by infection or treatment with rNcMIC3 [containing four epidermal growth factor (EGF domains] or human EGF. Blockade of EGFR-like in tachyzoites by AG1478 significantly reduced parasite proliferation in host cells. Our data suggested that the activation of tachyzoite EGFR-like might facilitate the intracellular proliferation of N. caninum.

Microarray-based genomic surveying of gene polymorphisms in Chlamydia trachomatis

OpenAIRE

Brunelle, Brian W; Nicholson, Tracy L; Stephens, Richard S

2004-01-01

By comparing two fully sequenced genomes of Chlamydia trachomatis using competitive hybridization on DNA microarrays, a logarithmic correlation was demonstrated between the signal ratio of the arrays and the 75-99% range of nucleotide identities of the genes. Variable genes within 14 uncharacterized strains of C. trachomatis were identified by array analysis and verified by DNA sequencing. These genes may be crucial for understanding chlamydial virulence and pathogenesis.

Chlamydia trachomatis IncA Is Localized to the Inclusion Membrane and Is Recognized by Antisera from Infected Humans and Primates†

OpenAIRE

Bannantine, John P.; Stamm, Walter E.; Suchland, Robert J.; Rockey, Daniel D.

1998-01-01

Chlamydia psittaci produces a collection of proteins, termed IncA, IncB, and IncC, that are localized to the chlamydial inclusion membrane. In this report we demonstrate that IncA is also produced by Chlamydia trachomatis. C. trachomatis IncA is structurally similar to C. psittaci IncA and is also localized to the inclusion membrane. Immunoblot analysis demonstrated that sera from C. trachomatis-infected patients and from experimentally infected monkeys both recognized C. trachomatis IncA.

Self-Collected versus Clinician-Collected Sampling for Chlamydia and Gonorrhea Screening: A Systemic Review and Meta-Analysis

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Lunny, Carole; Taylor, Darlene; Hoang, Linda; Wong, Tom; Gilbert, Mark; Lester, Richard; Krajden, Mel; Ogilvie, Gina

2015-01-01

Background The increases in STI rates since the late 1990s in Canada have occurred despite widespread primary care and targeted public health programs and in the setting of universal health care. More innovative interventions are required that would eliminate barriers to STI testing such as internet-based or mail-in home and community service testing for patients that are hard to reach, who refuse to go for clinician-based testing, or who decline an examination. Jurisdictions such as New Zealand and some American states currently use self-collected sampling, but without the required evidence to determine whether self-collected specimens are as accurate as clinician-collected specimens in terms of chlamydia and gonorrhea diagnostic accuracy. The objective of the review is to compare self-collected vaginal, urine, pharyngeal and rectal samples to our reference standard - clinician-collected cervical, urethral, pharyngeal and rectal sampling techniques to identify a positive specimen using nucleic acid amplification test assays. Methods The hierarchical summary receiver operating characteristic and the fixed effect models were used to assess the accuracy of comparable specimens that were collected by patients compared to clinicians. Sensitivity and specificity estimates with 95% confidence intervals (CI) were reported as our main outcome measures. Findings We included 21 studies based on over 6100 paired samples. Fourteen included studies examined chlamydia only, 6 compared both gonorrhea and chlamydia separately in the same study, and one examined gonorrhea. The six chlamydia studies comparing self-collection by vaginal swab to a clinician-collected cervical swab had the highest sensitivity (92%, 95% CI 87-95) and specificity (98%, 95% CI 97-99), compared to other specimen-types (urine/urethra or urine/cervix). Six studies compared urine self-samples to urethra clinician-collected samples in males and produced a sensitivity of 88% (95% CI 83-93) and a specificity of

Additional gonorrhea and Chlamydia infections found with rapid follow-up screening in men who have sex with men with an indication for HIV postexposure prophylaxis

NARCIS (Netherlands)

de Vrieze, Nynke H. N.; van Rooijen, Martijn S.; van de Loeff, Maarten Schim; de Vries, Henry J. C.

2014-01-01

Sexually transmitted infection was found in 16.5% of the men who have sex with men with a postexposure prophylaxis indication. Chlamydia and gonorrhea screening was repeated after 14 days. Among those who were initially sexually transmitted infection negative, 4.1% had chlamydia or gonorrhea. In

A novel synthetic peptide microarray assay detects Chlamydia species-specific antibodies in animal and human sera.

Science.gov (United States)

Sachse, Konrad; Rahman, Kh Shamsur; Schnee, Christiane; Müller, Elke; Peisker, Madlen; Schumacher, Thomas; Schubert, Evelyn; Ruettger, Anke; Kaltenboeck, Bernhard; Ehricht, Ralf

2018-03-16

Serological analysis of Chlamydia (C.) spp. infections is still mainly based on micro-immunofluorescence and ELISA. To overcome the limitations of conventional serology, we have designed a novel microarray carrying 52 synthetic peptides representing B-cell epitopes from immunodominant proteins of all 11 chlamydial species. The new assay has been validated using monospecific mouse hyperimmune sera. Subsequently, serum samples from cattle, sheep and humans with a known history of chlamydial infection were examined. For instance, the specific humoral response of sheep to treatment with a C. abortus vaccine has been visualized against a background of C. pecorum carriership. In samples from humans, dual infection with C. trachomatis and C. pneumoniae could be demonstrated. The experiments revealed that the peptide microarray assay was capable of simultaneously identifying specific antibodies to each Chlamydia spp. The actual assay represents an open platform test that can be complemented through future advances in Chlamydia proteome research. The concept of the highly parallel multi-antigen microarray proven in this study has the potential to enhance our understanding of antibody responses by defining not only a single quantitative response, but also the pattern of this response. The added value of using peptide antigens will consist in unprecedented serodiagnostic specificity.

Detection of Chlamydia trachomatis in endocervical smears of sexually active women in Manaus-AM, Brazil, by PCR

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Cristina Santos

Full Text Available Chlamydia trachomatis is now one of the most prevalent bacteria found in classic sexually transmissible diseases (STD, and as such, constitutes a serious public health problem. We examined the prevalence of Chlamydia trachomatis, by polymerase chain reaction (PCR, in 121 sexually active women who sought treatment for STD in the Alfredo da Matta Institute of Dermatology and Venerology and the Institute of Tropical Medicine of Amazonas in Manaus, Brazil. These women were examined by a specific PCR for the chlamydial plasmid, and the nature of the amplicon was determined by restriction analysis and DNA sequencing. The PCR diagnosis revealed a prevalence of 20.7% infected women.

Detection of Chlamydia trachomatis in endocervical smears of sexually active women in Manaus-AM, Brazil, by PCR

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Santos Cristina

2003-01-01

Full Text Available Chlamydia trachomatis is now one of the most prevalent bacteria found in classic sexually transmissible diseases (STD, and as such, constitutes a serious public health problem. We examined the prevalence of Chlamydia trachomatis, by polymerase chain reaction (PCR, in 121 sexually active women who sought treatment for STD in the Alfredo da Matta Institute of Dermatology and Venerology and the Institute of Tropical Medicine of Amazonas in Manaus, Brazil. These women were examined by a specific PCR for the chlamydial plasmid, and the nature of the amplicon was determined by restriction analysis and DNA sequencing. The PCR diagnosis revealed a prevalence of 20.7% infected women.

Growth in serum-free medium improves isolation of Chlamydia pneumoniae.

OpenAIRE

Maass, M; Essig, A; Marre, R; Henkel, W

1993-01-01

Infectivity titers were determined for eight Chlamydia pneumoniae strains simultaneously grown in serum-free and serum-supplemented cell culture media. Use of serum-free medium resulted in a 10- to 50-fold increase in the susceptibility of HL cells to chlamydial infection. Comparative primary isolation of a wild-type strain also produced higher inclusion counts in a serum-free environment. Serum-free cultivation is recommended to increase the efficiency of C. pneumoniae isolation from clinica...

Chlamydia trachomatis Genotypes and the Swedish New Variant among Urogenital Chlamydia trachomatis Strains in Finland

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Suvi Niemi

2011-01-01

Full Text Available Our aims were to genotype Chlamydia trachomatis strains present in urogenital samples and to investigate the occurrence of the Swedish new variant of C. trachomatis in Finland. We genotyped 160 C. trachomatis positive samples with ompA real-time PCR and analyzed 495 samples for the new variant. The three most prevalent genotypes were E (40%, F (28%, and G (13%. Only two specimens containing bacteria with the variant plasmid were detected. It seems that in Finland the percentage of infections due to genotypes F and G has slightly increased during the last 20 years. Genotypes E and G appear to be more common, and genotypes J/Ja and I/Ia appear to be less common in Europe than in the USA. Although the genotype E was the most common genotype among C. trachomatis strains, the new variant was rarely found in Finland.

The survival of Coxiella burnetii in soils

Science.gov (United States)

Evstigneeva, A. S.; Ul'Yanova, T. Yu.; Tarasevich, I. V.

2007-05-01

Coxiella burnetii is a pathogen of Q-fever—a widespread zoonosis. The effective adaptation of C. burnetii to intracellular existence is in contrast with its ability to survive in the environment outside the host cells and its resistance to chemical and physical agents. Its mechanism of survival remains unknown. However, its survival appears to be related to the developmental cycle of the microorganism itself, i.e., to the formation of its dormant forms. The survival of Coxiella burnetii was studied for the first time. The pathogenic microorganism was inoculated into different types of soil and cultivated under different temperatures. The survival of the pathogen was verified using a model with laboratory animals (mice). Viable C. burnetii were found in the soil even 20 days after their inoculation. The relationship between the organic carbon content in the soils and the survival of C. burnetii was revealed. Thus, the results obtained were the first to demonstrate that the soil may serve as a reservoir for the preservation and further spreading of the Q-fever pathogen in the environment, on the one hand, and reduce the risk of epidemics, on the other.

Impact of antiseptics on Chlamydia trachomatis growth.

Science.gov (United States)

Párducz, L; Eszik, I; Wagner, G; Burián, K; Endrész, V; Virok, D P

2016-10-01

Bacterial vaginosis is a frequent dysbiosis, where the normal lactobacillus-dominated flora is replaced by an anaerob/aerob polymicrobial flora. Bacterial vaginosis increases the risk of acquiring sexually transmitted infections (STI) including the most frequent Chlamydia trachomatis infections. Intravaginal antiseptics are part of the bacterial vaginosis treatment, and ideally they should also inhibit the bacterial vaginosis-related STI. Therefore, we tested the antichlamydial activity of four antiseptics: iodine aqueous solution, povidone-iodine, chlorhexidine and borax. First, we measured the impact of antiseptics on the viability of the HeLa cervical epithelial cells, and calculated the maximum nontoxic concentrations. Next, we infected the cells with C. trachomatis preincubated for 1 h with the particular antiseptic. The chlamydial growth was measured by direct quantitative PCR (qPCR) of the infected cells. The minimal inhibitory concentrations (MIC) of chlorhexidine and povidone-iodine were 3·91 and 97 μg ml(-1) respectively; however, the MIC of chlorhexidine was close to its maximum nontoxic concentration. The iodine aqueous solution and the borax showed no antichlamydial activity. Our in vitro studies showed that chlorhexidine and particularly povidone-iodine are potentially able to limit the bacterial vaginosis-related C. trachomatis infection. We measured the antichlamydial effects of various antiseptics. These antiseptics are being used for the treatment of bacterial vaginosis, but their effect on the bacterial vaginosis-related sexually transmitted infections, particularly the most frequent Chlamydia trachomatis (C. trachomatis) infections has not been investigated. We showed that povidone-iodine (Betadine) inhibited the chlamydial growth in concentrations that was not toxic to the epithelial cells. We concluded that due to its additional antichlamydial effect, povidone-iodine could be a preferable antiseptic in bacterial vaginosis treatment. �

Profiling of Intracellular Metabolites: An Approach to Understanding the Characteristic Physiology of Mycobacterium leprae.

Science.gov (United States)

Miyamoto, Yuji; Mukai, Tetsu; Matsuoka, Masanori; Kai, Masanori; Maeda, Yumi; Makino, Masahiko

2016-08-01

Mycobacterium leprae is the causative agent of leprosy and also known to possess unique features such as inability to proliferate in vitro. Among the cellular components of M. leprae, various glycolipids present on the cell envelope are well characterized and some of them are identified to be pathogenic factors responsible for intracellular survival in host cells, while other intracellular metabolites, assumed to be associated with basic physiological feature, remain largely unknown. In the present study, to elucidate the comprehensive profile of intracellular metabolites, we performed the capillary electrophoresis-mass spectrometry (CE-MS) analysis on M. leprae and compared to that of M. bovis BCG. Interestingly, comparison of these two profiles showed that, in M. leprae, amino acids and their derivatives are significantly accumulated, but most of intermediates related to central carbon metabolism markedly decreased, implying that M. leprae possess unique metabolic features. The present study is the first report demonstrating the unique profiles of M. leprae metabolites and these insights might contribute to understanding undefined metabolism of M. leprae as well as pathogenic characteristics related to the manifestation of the disease.

Targeted Delivery of Amoxicillin to C. trachomatis by the Transferrin Iron Acquisition Pathway.

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Jun Hai

Full Text Available Weak intracellular penetration of antibiotics makes some infections difficult to treat. The Trojan horse strategy for targeted drug delivery is among the interesting routes being explored to overcome this therapeutic difficulty. Chlamydia trachomatis, as an obligate intracellular human pathogen, is responsible for both trachoma and sexually transmitted diseases. Chlamydia develops in a vacuole and is therefore protected by four membranes (plasma membrane, bacterial inclusion membrane, and bacterial membranes. In this work, the iron-transport protein, human serum-transferrin, was used as a Trojan horse for antibiotic delivery into the bacterial vacuole. Amoxicillin was grafted onto transferrin. The transferrin-amoxicillin construct was characterized by mass spectrometry and absorption spectroscopy. Its affinity for transferrin receptor 1, determined by fluorescence emission titration [KaffTf-amox = (1.3 ± 1.0 x 108], is very close to that of transferrin [4.3 x 108]. Transmission electron and confocal microscopies showed a co-localization of transferrin with the bacteria in the vacuole and were also used to evaluate the antibiotic capability of the construct. It is significantly more effective than amoxicillin alone. These promising results demonstrate targeted delivery of amoxicillin to suppress Chlamydia and are of interest for Chlamydiaceae and maybe other intracellular bacteria therapies.