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Sample records for shigella flexneri 5a

  1. Sepsis por shigella flexneri

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    César Cabrera C

    2005-04-01

    Full Text Available Se presenta un caso raro de sepsis por Shigella flexneri en una paciente de 45 años de edad quien estando hospitalizada para el estudio de un tumor cerebral, requirió el uso de manitol y dosis altas de corticoides; luego de ello presenta deposiciones líquidas con moco y sangre, desarrolla síndrome de respuesta inflamatoria sistémica, luego se aísla Shigella flexneri en el hemocultivo; recibió tratamiento antibiótico con ciprofloxacina. Se describen las características del caso y se comenta de acuerdo con la revisión de literatura.

  2. Antibodies against Shigella flexneri adhesion molecule outer ...

    African Journals Online (AJOL)

    OMP) as an adhesion factor and examine its ability to cross-react with the OMPs of other Shigella species. Methods: OMP was isolated from the bacterium S. flexneri after shaving the pili using a pili bacterial cutter in a solution of 0.5 ...

  3. Tyrosine kinases, drugs, and Shigella flexneri dissemination.

    Science.gov (United States)

    Dragoi, Ana-Maria; Agaisse, Hervé

    2014-01-01

    Shigella flexneri is an enteropathogenic bacterium responsible for approximately 100 million cases of severe dysentery each year. S. flexneri colonization of the human colonic epithelium is supported by direct spread from cell to cell, which relies on actin-based motility. We have recently uncovered that, in intestinal epithelial cells, S. flexneri actin-based motility is regulated by the Bruton's tyrosine kinase (Btk). Consequently, treatment with Ibrutinib, a specific Btk inhibitor currently used in the treatment of B-cell malignancies, effectively impaired S. flexneri spread from cell to cell. Thus, therapeutic intervention capitalizing on drugs interfering with host factors supporting the infection process may represent an effective alternative to treatments with antimicrobial compounds.

  4. Complete genome sequence of Shigella flexneri 5b and comparison with Shigella flexneri 2a

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    Xue Ying

    2006-07-01

    Full Text Available Abstract Background Shigella bacteria cause dysentery, which remains a significant threat to public health. Shigella flexneri is the most common species in both developing and developed countries. Five Shigella genomes have been sequenced, revealing dynamic and diverse features. To investigate the intra-species diversity of S. flexneri genomes further, we have sequenced the complete genome of S. flexneri 5b strain 8401 (abbreviated Sf8401 and compared it with S. flexneri 2a (Sf301. Results The Sf8401 chromosome is 4.5-Mb in size, a little smaller than that of Sf301, mainly because the former lacks the SHI-1 pathogenicity island (PAI. Compared with Sf301, there are 6 inversions and one translocation in Sf8401, which are probably mediated by insertion sequences (IS. There are clear differences in the known PAIs between these two genomes. The bacteriophage SfV segment remaining in SHI-O of Sf8401 is clearly larger than the remnants of bacteriophage SfII in Sf301. SHI-1 is absent from Sf8401 but a specific related protein is found next to the pheV locus. SHI-2 is involved in one intra-replichore inversion near the origin of replication, which may change the expression of iut/iuc genes. Moreover, genes related to the glycine-betaine biosynthesis pathway are present only in Sf8401 among the known Shigella genomes. Conclusion Our data show that the two S. flexneri genomes are very similar, which suggests a high level of structural and functional conservation between the two serotypes. The differences reflect different selection pressures during evolution. The ancestor of S. flexneri probably acquired SHI-1 and SHI-2 before SHI-O was integrated and the serotypes diverged. SHI-1 was subsequently deleted from the S. flexneri 5b genome by recombination, but stabilized in the S. flexneri 2a genome. These events may have contributed to the differences in pathogenicity and epidemicity between the two serotypes of S. flexneri.

  5. Two Cases of Vulvovaginitis Caused by Shigella flexneri and Shigella sonnei: a Case Report

    OpenAIRE

    Bayramoğlu, Gülçin; Aydın, Faruk; Karagüzel, Gülay; İmamoğlu, Mustafa; Ökten, Ayşenur

    2014-01-01

    Vulvovaginitis caused by Shigella species (Shigella spp.) has rarely been reported. This paper describes two cases of prepubertal vulvovaginitis, presenting with a bloody and purulent vaginal discharge, separately caused by ampicillin-resistant Shigella flexneri and trimethoprim-sulfomethoxazoleresistant Shigella sonnei. Our conclusions are that Shigella spp. is the potential cause of vulvovaginitis in prepubertal girls in developing countries where these pathogens are endemic, and identifica...

  6. Two Cases of Vulvovaginitis Caused by Shigella flexneri and Shigella sonnei: a Case Report

    OpenAIRE

    Bayramoğlu, Gülçin; Aydın, Faruk; Karagüzel, Gülay; İmamoğlu, Mustafa; Ökten, Ayşenur

    2012-01-01

    Vulvovaginitis caused by Shigella species (Shigella spp.) has rarely been reported. This paper describes two cases of prepubertal vulvovaginitis, presenting with a bloody and purulent vaginal discharge, separately caused by ampicillin-resistant Shigella flexneri and trimethoprim-sulfomethoxazoleresistant Shigella sonnei. Our conclusions are that Shigella spp. is the potential cause of vulvovaginitis in prepubertal girls in developing countries where these pathogens are endemic, and identifica...

  7. Multidrug resistant shigella flexneri infection simulating intestinal intussusception

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    Srirangaraj Sreenivasan

    2016-01-01

    Full Text Available Shigella enteritis remains an important cause of mortality and morbidity in all age groups, in developing as well as developed countries. Owing to the emerging resistance to multiple antibiotics among Shigella spp., it has been recognized as a major global public health concern and warrants constant monitoring of its resistance pattern. We report a case of segmental ileitis caused by non.-ESBL producing multidrug resistant Shigella flexneri in an infant clinically mimicking intussusception, which was effectively treated by ceftriaxone.

  8. Osmoregulated periplasmic glucans synthesis gene family of Shigella flexneri

    Science.gov (United States)

    Osmoregulated periplasmic glucans (OPGs) of foodborne enteropathogen Shigella flexneri were characterized. OPGs were composed of 100 percent glucose with 2-linked glucose as the most abundant residue with terminal glucose, 2-linked and 2,6-linked glucose also present in high quantities. Most dominan...

  9. Two Cases of Vulvovaginitis Caused by Shigella flexneri and Shigella sonnei: a Case Report

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    Gülçin Bayramoğlu

    2012-03-01

    Full Text Available Vulvovaginitis caused by Shigella species (Shigella spp. has rarely been reported. This paper describes two cases of prepubertal vulvovaginitis, presenting with a bloody and purulent vaginal discharge, separately caused by ampicillin-resistant Shigella flexneri and trimethoprim-sulfomethoxazole-resistant Shigella sonnei. Our conclusions are that Shigella spp. is the potential cause of vulvovaginitis in prepubertal girls in developing countries where these pathogens are endemic, and identification of the bacteria and making antibiotic susceptibility testing in these cases should not be overlooked.

  10. CsrA and Cra influence Shigella flexneri pathogenesis.

    Science.gov (United States)

    Gore, Aja L; Payne, Shelley M

    2010-11-01

    Shigella flexneri is a facultative intracellular pathogen that invades and disrupts the colonic epithelium. In order to thrive in the host, S. flexneri must adapt to environmental conditions in the gut and within the eukaryotic cytosol, including variability in the available carbon sources and other nutrients. We examined the roles of the carbon consumption regulators CsrA and Cra in a cell culture model of S. flexneri virulence. CsrA is an activator of glycolysis and a repressor of gluconeogenesis, and a csrA mutant had decreased attachment and invasion of cultured cells. Conversely, Cra represses glycolysis and activates gluconeogenesis, and the cra mutant had an increase in both attachment and invasion compared to the wild-type strain. Both mutants were defective in plaque formation. The importance of the glycolytic pathway in invasion and plaque formation was confirmed by testing the effect of a mutation in the glycolysis gene pfkA. The pfkA mutant was noninvasive and had cell surface alterations as indicated by decreased sensitivity to SDS and an altered lipopolysaccharide profile. The loss of invasion by the csrA and pfkA mutants was due to decreased expression of the S. flexneri virulence factor regulators virF and virB, resulting in decreased production of Shigella invasion plasmid antigens (Ipa). These data indicate that regulation of carbon metabolism and expression of the glycolysis gene pfkA are critical for synthesis of the virulence gene regulators VirF and VirB, and both the glycolytic and gluconeogenic pathways influence steps in S. flexneri invasion and plaque formation.

  11. Whole-Genome Sequencing for National Surveillance of Shigella flexneri

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    Marie A. Chattaway

    2017-09-01

    Full Text Available National surveillance of Shigella flexneri ensures the rapid detection of outbreaks to facilitate public health investigation and intervention strategies. In this study, we used whole-genome sequencing (WGS to type S. flexneri in order to detect linked cases and support epidemiological investigations. We prospectively analyzed 330 isolates of S. flexneri received at the Gastrointestinal Bacteria Reference Unit at Public Health England between August 2015 and January 2016. Traditional phenotypic and WGS sub-typing methods were compared. PCR was carried out on isolates exhibiting phenotypic/genotypic discrepancies with respect to serotype. Phylogenetic relationships between isolates were analyzed by WGS using single nucleotide polymorphism (SNP typing to facilitate cluster detection. For 306/330 (93% isolates there was concordance between serotype derived from the genome and phenotypic serology. Discrepant results between the phenotypic and genotypic tests were attributed to novel O-antigen synthesis/modification gene combinations or indels identified in O-antigen synthesis/modification genes rendering them dysfunctional. SNP typing identified 36 clusters of two isolates or more. WGS provided microbiological evidence of epidemiologically linked clusters and detected novel O-antigen synthesis/modification gene combinations associated with two outbreaks. WGS provided reliable and robust data for monitoring trends in the incidence of different serotypes over time. SNP typing can be used to facilitate outbreak investigations in real-time thereby informing surveillance strategies and providing the opportunities for implementing timely public health interventions.

  12. Polymerase chain reaction for detection of invasive Shigella flexneri in food.

    OpenAIRE

    Lampel, K A; Jagow, J A; Trucksess, M; Hill, W E

    1990-01-01

    The polymerase chain reaction (PCR) was used to amplify a 760-base-pair (bp) fragment with the 220-kbp invasive plasmids of enteroinvasive Escherichia coli, Shigella flexneri, Shigella dysenteriae, Shigella boydii, and Shigella sonnei as templates. This PCR product was easily detected by agarose gel electrophoresis. A 210-bp AccI-PstI fragment lying within the amplified region was used as a probe in Southern hybridization blots and showed that the PCR-generated product was derived from the in...

  13. The Shigella flexneri OspB effector: an early immunomodulator.

    Science.gov (United States)

    Ambrosi, Cecilia; Pompili, Monica; Scribano, Daniela; Limongi, Dolores; Petrucca, Andrea; Cannavacciuolo, Sonia; Schippa, Serena; Zagaglia, Carlo; Grossi, Milena; Nicoletti, Mauro

    2015-01-01

    Through the action of the type three secretion system (T3SS) Shigella flexneri delivers several effectors into host cells to promote cellular invasion, multiplication and to exploit host-cell signaling pathways to modulate the host innate immune response. Although much progress has been made in the understanding of many type III effectors, the molecular and cellular mechanism of the OspB effector is still poorly characterized. In this study we present new evidence that better elucidates the role of OspB as pro-inflammatory factor at very early stages of infection. Indeed, we demonstrate that, during the first hour of infection, OspB is required for full activation of ERK1/2 and p38 MAPKs and the cytosolic phospholipase A(2) (cPLA(2)). Activation of cPLA(2) ultimately leads to the production and secretion of PMN chemoattractant metabolite(s) uncoupled with release of IL-8. Moreover, we also present evidence that OspB is required for the development of the full and promptly inflammatory reaction characteristic of S. flexneri wild-type infection in vivo. Based on OspB and OspF similarity (both effectors share similar transcription regulation, temporal secretion into host cells and nuclear localization) we hypothesized that OspB and OspF effectors may form a pair aimed at modulating the host cell response throughout the infection process, with opposite effects. A model is presented to illustrate how OspB activity would promote S. flexneri invasion and bacterial dissemination at early critical phases of infection. Copyright © 2014 Elsevier GmbH. All rights reserved.

  14. Crystal structure and functional characterization of SF216 from Shigella flexneri.

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    Kim, Ha-Neul; Seok, Seung-Hyeon; Lee, Yoo-Sup; Won, Hyung-Sik; Seo, Min-Duk

    2017-11-01

    Shigella flexneri is a Gram-negative anaerobic bacterium that causes highly infectious bacterial dysentery in humans. Here, we solved the crystal structure of SF216, a hypothetical protein from the S. flexneri 5a strain M90T, at 1.7 Å resolution. The crystal structure of SF216 represents a homotrimer stabilized by intersubunit interactions and ion-mediated electrostatic interactions. Each subunit consists of three β-strands and five α-helices with the β-β-β-α-α-α-α-α topology. Based on the structural information, we also demonstrate that SF216 shows weak ribonuclease activity by a fluorescence quenching assay. Furthermore, we identify potential druggable pockets (putative hot spots) on the surface of the SF216 structure by computational mapping. © 2017 Federation of European Biochemical Societies.

  15. Molecular and Cellular Mechanisms of Shigella flexneri Dissemination.

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    Agaisse, Hervé

    2016-01-01

    The intracellular pathogen Shigella flexneri is the causative agent of bacillary dysentery in humans. The disease is characterized by bacterial invasion of intestinal cells, dissemination within the colonic epithelium through direct spread from cell to cell, and massive inflammation of the intestinal mucosa. Here, we review the mechanisms supporting S. flexneri dissemination. The dissemination process primarily relies on actin assembly at the bacterial pole, which propels the pathogen throughout the cytosol of primary infected cells. Polar actin assembly is supported by polar expression of the bacterial autotransporter family member IcsA, which recruits the N-WASP/ARP2/3 actin assembly machinery. As motile bacteria encounter cell-cell contacts, they form plasma membrane protrusions that project into adjacent cells. In addition to the ARP2/3-dependent actin assembly machinery, protrusion formation relies on formins and myosins. The resolution of protrusions into vacuoles occurs through the collapse of the protrusion neck, leading to the formation of an intermediate membrane-bound compartment termed vacuole-like protrusions (VLPs). VLP formation requires tyrosine kinase and phosphoinositide signaling in protrusions, which relies on the integrity of the bacterial type 3 secretion system (T3SS). The T3SS is also required for escaping double membrane vacuoles through the activity of the T3SS translocases IpaB and IpaC, and the effector proteins VirA and IcsB. Numerous factors supporting envelope biogenesis contribute to IcsA exposure and maintenance at the bacterial pole, including LPS synthesis, membrane proteases, and periplasmic chaperones. Although less characterized, the assembly and function of the T3SS in the context of bacterial dissemination also relies on factors supporting envelope biogenesis. Finally, the dissemination process requires the adaptation of the pathogen to various cellular compartments through transcriptional and post-transcriptional mechanisms.

  16. Molecular and Cellular mechanisms of Shigella flexneri dissemination

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    Herve eAgaisse

    2016-03-01

    Full Text Available The intracellular pathogen Shigella flexneri is the causative agent of bacillary dysentery in humans. The disease is characterized by bacterial invasion of intestinal cells, dissemination within the colonic epithelium through direct spread from cell to cell, and massive inflammation of the intestinal mucosa. Here, we review the mechanisms supporting S. flexneri dissemination. The dissemination process primarily relies on actin assembly at the bacterial pole, which propels the pathogen throughout the cytosol of primary infected cells. Polar actin assembly is supported by polar expression of the bacterial autotransporter family member IcsA, which recruits the N-WASP/ARP2/3 actin assembly machinery. As motile bacteria encounter cell-cell contacts, they form plasma membrane protrusions that project into adjacent cells. In addition to the ARP2/3-dependent actin assembly machinery, protrusion formation relies on formins and myosins. The resolution of protrusions into vacuoles occurs through the collapse of the protrusion neck, leading to the formation of an intermediate membrane-bound compartment termed vacuole-like protrusions (VLPs. VLP formation requires tyrosine kinase and phosphoinositide signaling in protrusions, which relies on the integrity of the bacterial type 3 secretion system (T3SS. The T3SS is also required for escaping double membrane vacuoles through the activity of the T3SS translocases IpaB and IpaC, and the effector proteins VirA and IcsB. Numerous factors supporting envelope biogenesis contribute to IcsA exposure and maintenance at the bacterial pole, including LPS synthesis, membrane proteases, and periplasmic chaperones. Although less characterized, the assembly and function of the T3SS in the context of bacterial dissemination also relies on factors supporting envelope biogenesis. Finally, the dissemination process requires the adaptation of the pathogen to various cellular compartments through transcriptional and post

  17. Comparative proteomic analysis of outer membrane vesicles from Shigella flexneri under different culture conditions

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Yong; Liu, Liguo; Fu, Hua; Wei, Candong, E-mail: weicando@ipbcams.ac.cn; Jin, Qi, E-mail: zdsys@vip.sina.com

    2014-10-31

    Highlights: • We utilized mTRAQ-based quantification to study protein changes in Congo red-induced OMVs. • A total of 148 proteins were identified in S. flexneri-derived OMVs. • Twenty-eight and five proteins are significantly up- and down-regulated in the CR-induced OMV, respectively. • The result implied that a special sorting mechanism of particular proteins into OMVs may exist. • Key node proteins in the protein interaction network might be important for pathogenicity. - Abstract: The production of outer membrane vesicles (OMVs) is a common and regulated process of gram-negative bacteria. Nonetheless, the processes of Shigella flexneri OMV production still remain unclear. S. flexneri is the causative agent of endemic shigellosis in developing countries. The Congo red binding of strains is associated with increased infectivity of S. flexneri. Therefore, understanding the modulation pattern of OMV protein expression induced by Congo red will help to elucidate the bacterial pathogenesis. In the present study, we investigated the proteomic composition of OMVs and the change in OMV protein expression induced by Congo red using mTRAQ-based quantitative comparative proteomics. mTRAQ labelling increased the confidence in protein identification, and 148 total proteins were identified in S. flexneri-derived OMVs. These include a variety of important virulence factors, including Ipa proteins, TolC family, murein hydrolases, and members of the serine protease autotransporters of Enterobacteriaceae (SPATEs) family. Among the identified proteins, 28 and five proteins are significantly up- and down-regulated in the Congo red-induced OMV, respectively. Additionally, by comprehensive comparison with previous studies focused on DH5a-derived OMV, we identified some key node proteins in the protein–protein interaction network that may be involved in OMV biogenesis and are common to all gram-negative bacteria.

  18. Comparative proteomic analysis of outer membrane vesicles from Shigella flexneri under different culture conditions

    International Nuclear Information System (INIS)

    Chen, Yong; Liu, Liguo; Fu, Hua; Wei, Candong; Jin, Qi

    2014-01-01

    Highlights: • We utilized mTRAQ-based quantification to study protein changes in Congo red-induced OMVs. • A total of 148 proteins were identified in S. flexneri-derived OMVs. • Twenty-eight and five proteins are significantly up- and down-regulated in the CR-induced OMV, respectively. • The result implied that a special sorting mechanism of particular proteins into OMVs may exist. • Key node proteins in the protein interaction network might be important for pathogenicity. - Abstract: The production of outer membrane vesicles (OMVs) is a common and regulated process of gram-negative bacteria. Nonetheless, the processes of Shigella flexneri OMV production still remain unclear. S. flexneri is the causative agent of endemic shigellosis in developing countries. The Congo red binding of strains is associated with increased infectivity of S. flexneri. Therefore, understanding the modulation pattern of OMV protein expression induced by Congo red will help to elucidate the bacterial pathogenesis. In the present study, we investigated the proteomic composition of OMVs and the change in OMV protein expression induced by Congo red using mTRAQ-based quantitative comparative proteomics. mTRAQ labelling increased the confidence in protein identification, and 148 total proteins were identified in S. flexneri-derived OMVs. These include a variety of important virulence factors, including Ipa proteins, TolC family, murein hydrolases, and members of the serine protease autotransporters of Enterobacteriaceae (SPATEs) family. Among the identified proteins, 28 and five proteins are significantly up- and down-regulated in the Congo red-induced OMV, respectively. Additionally, by comprehensive comparison with previous studies focused on DH5a-derived OMV, we identified some key node proteins in the protein–protein interaction network that may be involved in OMV biogenesis and are common to all gram-negative bacteria

  19. Effect of guinea pig or monkey colonic mucus on Shigella aggregation and invasion of HeLa cells by Shigella flexneri 1b and 2a.

    OpenAIRE

    Dinari, G; Hale, T L; Washington, O; Formal, S B

    1986-01-01

    The effects of guinea pig and rhesus monkey colonic mucus preparations on Shigella aggregation and invasion of HeLa cell monolayers by Shigella flexneri serotype 1b, 2a, and 5 strains were investigated. Guinea pig mucus caused agglutination of S. flexneri serotype 1b but not of S. flexneri serotype 2a or 5. Guinea pig mucus also inhibited HeLa cell invasion by S. flexneri serotypes 1b and 2a. Monkey mucus neither agglutinated any Shigella strain nor inhibited HeLa cell invasion.

  20. Shigella flexneri infection in Caenorhabditis elegans: cytopathological examination and identification of host responses.

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    Divya T George

    Full Text Available The Gram-negative bacterium Shigella flexneri is the causative agent of shigellosis, a diarrhoeal disease also known as bacillary dysentery. S. flexneri infects the colonic and rectal epithelia of its primate host and induces a cascade of inflammatory responses that culminates in the destruction of the host intestinal lining. Molecular characterization of host-pathogen interactions in this infection has been challenging due to the host specificity of S. flexneri strains, as it strictly infects humans and non-human primates. Recent studies have shown that S. flexneri infects the soil dwelling nematode Caenorhabditis elegans, however, the interactions between S. flexneri and C. elegans at the cellular level and the cause of nematode death are unknown. Here we attempt to gain insight into the complex host-pathogen interactions between S. flexneri and C. elegans. Using transmission electron microscopy, we show that live S. flexneri cells accumulate in the nematode intestinal lumen, produce outer membrane vesicles and invade nematode intestinal cells. Using two-dimensional differential in-gel electrophoresis we identified host proteins that are differentially expressed in response to S. flexneri infection. Four of the identified genes, aco-1, cct-2, daf-19 and hsp-60, were knocked down using RNAi and ACO-1, CCT-2 and DAF-19, which were identified as up-regulated in response to S. flexneri infection, were found to be involved in the infection process. aco-1 RNAi worms were more resistant to S. flexneri infection, suggesting S. flexneri-mediated disruption of host iron homeostasis. cct-2 and daf-19 RNAi worms were more susceptible to infection, suggesting that these genes are induced as a protective mechanism by C. elegans. These observations further our understanding of the processes involved in S. flexneri infection of C. elegans, which is immensely beneficial to the routine use of this new in vivo model to study S. flexneri pathogenesis.

  1. Antigen-Specific lgA B Memory Cell Responses to Shigella Antigens Elicited in Volunteers Immunized with Live Attenuated Shigella flexneri 2a Oral Vaccine Candidates

    Science.gov (United States)

    2011-01-01

    167. [10] E.V. Oaks, T.L. Hale, S.B. Formal, Serum immune response to Shigella protein antigens in rhesus monkeys and humans infected with Shigella ...cell responses to Shigella antigens elicited in volunteers immunized with live attenuated Shigella flexneri 2a oral vaccine candidates J.K. Simona,b... Shigella ;. B cell memory; Immunoglobulin lgA; Mucosal immunity Abstract We studied the induction of antigen-specific lgA memory B cells (BM) in

  2. Structural analysis of the active site architecture of the VapC toxin from Shigella flexneri

    DEFF Research Database (Denmark)

    Xu, Kehan; Dedic, Emil; Brodersen, Ditlev Egeskov

    2016-01-01

    The VapC toxin from the Shigella flexneri 2a virulence plasmid pMYSH6000 belongs to the PIN domain protein family, which is characterized by a conserved fold with low amino acid sequence conservation. The toxin is a bona fide Mg2+-dependent ribonuclease and has been shown to target initiator t...

  3. Structural organization of the needle complex of the type III secretion apparatus of Shigella flexneri

    NARCIS (Netherlands)

    Sani, Musa; Allaoui, Abdelmounaaïm; Fusetti, Fabrizia; Oostergetel, Gert T.; Keegstra, Wilko; Boekema, Egbert J.

    2007-01-01

    The secretion apparatus known as the needle complex (NC) from the bacterium Shigella flexneri was studied by single particle electron microscopy. The isolated intact NC appears in projection to be composed of a basal body consisting of seven rings and a protruding needle appendage. A comparison of

  4. Role of anionic charges of periplasmic glucans of Shigella flexneri in overcoming detergent stress

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    Osmoregulated periplasmic glucans (OPGs) are synthesized by the members of the family Enterobacteriaceae when grown under low osmotic growth conditions. Enteropathogens such as Shigella flexneri spend considerable time outside the host environment such as irrigation waters where low nutrient low os...

  5. Structural mimicry for vinculin activation by IpaA, a virulence factor of Shigella flexneri

    NARCIS (Netherlands)

    Hamiaux, Cyril; Eerde, André van; Parsot, Claude; Broos, Jaap; Dijkstra, Bauke W.

    2006-01-01

    Invasion of epithelial cells by Shigella flexneri is characterized by cytoskeletal rearrangements of the host cell membrane, promoting internalization of the bacterium. The bacterial effector IpaA is injected into the epithelial cell by a type III secretion apparatus and recruits vinculin to

  6. Plasmid-Mediated Quinolone Resistance in Shigella flexneri Isolated From Macaques

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    Anthony J. Mannion

    2018-03-01

    Full Text Available Non-human primates (NHPs for biomedical research are commonly infected with Shigella spp. that can cause acute dysentery or chronic episodic diarrhea. These animals are often prophylactically and clinically treated with quinolone antibiotics to eradicate these possible infections. However, chromosomally- and plasmid-mediated antibiotic resistance has become an emerging concern for species in the family Enterobacteriaceae. In this study, five individual isolates of multi-drug resistant Shigella flexneri were isolated from the feces of three macaques. Antibiotic susceptibility testing confirmed resistance or decreased susceptibility to ampicillin, amoxicillin-clavulanic acid, cephalosporins, gentamicin, tetracycline, ciprofloxacin, enrofloxacin, levofloxacin, and nalidixic acid. S. flexneri isolates were susceptible to trimethoprim-sulfamethoxazole, and this drug was used to eradicate infection in two of the macaques. Plasmid DNA from all isolates was positive for the plasmid-encoded quinolone resistance gene qnrS, but not qnrA and qnrB. Conjugation and transformation of plasmid DNA from several S. flexneri isolates into antibiotic-susceptible Escherichia coli strains conferred the recipients with resistance or decreased susceptibility to quinolones and beta-lactams. Genome sequencing of two representative S. flexneri isolates identified the qnrS gene on a plasmid-like contig. These contigs showed >99% homology to plasmid sequences previously characterized from quinolone-resistant Shigella flexneri 2a and Salmonella enterica strains. Other antibiotic resistance genes and virulence factor genes were also identified in chromosome and plasmid sequences in these genomes. The findings from this study indicate macaques harbor pathogenic S. flexneri strains with chromosomally- and plasmid-encoded antibiotic resistance genes. To our knowledge, this is the first report of plasmid-mediated quinolone resistance in S. flexneri isolated from NHPs and warrants

  7. Polymerase chain reaction for detection of invasive Shigella flexneri in food.

    Science.gov (United States)

    Lampel, K A; Jagow, J A; Trucksess, M; Hill, W E

    1990-06-01

    The polymerase chain reaction (PCR) was used to amplify a 760-base-pair (bp) fragment with the 220-kbp invasive plasmids of enteroinvasive Escherichia coli, Shigella flexneri, Shigella dysenteriae, Shigella boydii, and Shigella sonnei as templates. This PCR product was easily detected by agarose gel electrophoresis. A 210-bp AccI-PstI fragment lying within the amplified region was used as a probe in Southern hybridization blots and showed that the PCR-generated product was derived from the invasive plasmid. The application of PCR as a rapid method to detect enteroinvasive bacteria in foods was tested by inoculating lettuce with 10(4) S. flexneri cells per g in shigella broth base. Plasmid DNA was isolated from cultures of inoculated and uninoculated lettuce in broth after 0, 4, and 24 h of incubation. With the PCR, the 760-bp fragment was generated only from lettuce inoculated with S. flexneri, as shown by gel electrophoresis and confirmed both by Southern blotting and by nucleotide sequencing of the amplified region. Because the isolation of plasmid DNA, the performance of PCR, and gel electrophoresis all can be completed in 6 to 7 h, invasive enteric bacteria can be detected in less than 1 day.

  8. A novel anti-virulence gene revealed by proteomic analysis in Shigella flexneri 2a

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    Ying Tianyi

    2010-06-01

    Full Text Available Abstract Background Shigella flexneri is a gram-negative, facultative pathogen that causes the majority of communicable bacterial dysenteries in developing countries. The virulence factors of S. flexneri have been shown to be produced at 37 degrees C but not at 30 degrees C. To discover potential, novel virulence-related proteins of S. flexneri, we performed differential in-gel electrophoresis (DIGE analysis to measure changes in the expression profile that are induced by a temperature increase. Results The ArgT protein was dramatically down-regulated at 37 degrees C. In contrast, the ArgT from the non-pathogenic E. coli did not show this differential expression as in S. flexneri, which suggested that argT might be a potential anti-virulence gene. Competitive invasion assays in HeLa cells and in BALB/c mice with argT mutants were performed, and the results indicated that the over-expression of ArgTY225D would attenuate the virulence of S. flexneri. A comparative proteomic analysis was subsequently performed to investigate the effects of ArgT in S. flexneri at the molecular level. We show that HtrA is differentially expressed among different derivative strains. Conclusion Gene argT is a novel anti-virulence gene that may interfere with the virulence of S. flexneri via the transport of specific amino acids or by affecting the expression of the virulence factor, HtrA.

  9. The effect of quorum sensing system for growth competitiveness on Shigella flexneri.

    Science.gov (United States)

    Xu, Ping; Yang, Jing; Lu, Li-lan; Feng, Er-ling; Wang, Heng-liang; Lu, Ying; Zhu, Li

    2015-05-01

    Quorum sensing (QS) regulates the onset of bacterial social responses related to cell density. Comparison between the gene sequences of all components of QS system of Escherichia coli and Shigella strains, shows that the QS system is generally lost or mutated in Shigella. Since AI-2 is produced and processed by the lsr operon, we analyzed the potential function of the lsr operon. We first detected AI-2 in Shigella flexneri 2a strain 301 through the reporter bacteria Vibrio harveyi BB170, indicating that S. flexneri can produce AI-2. Then, the lsr operon of E. coli MG1655 was cloned into S. flexneri using the Golden Gate method. Colony counting experiments showed that the QS system recovery strain had growth advantage over the wild-type strain when they were mixed and cultured. The preliminary comparative proteomics analysis showed that the lsr operon could be expressed and the abundance of stress response proteins also changed when the QS system was introduced into S. flexneri.

  10. Laboratory based surveillance of travel-related Shigella sonnei and Shigella flexneri in Alberta from 2002 to 2007

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    Ferrato Christina

    2010-11-01

    Full Text Available Abstract Between 2002 and 2007, travel related cases of Shigella sonnei and S. flexneri in Alberta, Canada were acquired from Central America, the Indian subcontinent and North America. Of this group, resistance to ciprofloxacin and nalidixic acid was identified in isolates from patients who had travelled to the Indian subcontinent. This study provides a Canadian perspective to a growing body of literature linking ciprofloxacin and nalidixic acid resistance to travel to the Indian subcontinent. Shigella is a common cause of diarrheal illness in North America with a rate of 2.0 per 100,000 in Canada 1 and a rate of 3.2 per 100,000 in the United States 23. Imported cases of Shigella infections have been reported in developed countries following travel to a foreign or developing country 45 and may be impacted by factors including socio-economic factors 6, food distribution networks 5 and microbiologic factors 7. Across multiple geographic regions, high rates of antimicrobial resistance to multiple agents (e.g. sulfonamides, tetracycline, chloramphenicol, ampicillin, and trimethoprim-sulfamethoxazole have limited the choices for empiric antimicrobial therapy required to manage Shigella infections and reduce fecal excretion of the bacteria 8910 with descriptions of shifting species dominance and changes in antimicrobial susceptibility 1011. Generally, Shigella flexneri and Shigella sonnei are the dominant species and are heavily impacted by changes in antimicrobial susceptibility 1213. This study identifies the global regions associated with travel-related cases of S. flexneri and S. sonnei in Alberta, Canada and compares antibiotic resistance patterns of these isolates for 2002 to 2007 inclusive. Specimens collected 2002-2007 (inclusive from S. flexneri and S. sonnei infections in Alberta, Canada were included for study. Data collected at time of specimen submission included: date of specimen collection, outbreak association if present, travel

  11. Cefotaximase and AmpC-producing Shigella flexneri in case of dysentery from southern India

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    S Oommen

    2013-01-01

    Full Text Available Diarrhoea and dysentery caused by Shigella spp. are major public health concerns. Emerging multidrug resistance (MDR in this pathogen further complicates this disease. Extended spectrum β-lactamases (ESBLs have been described in this pathogen, which significantly compromises the treatment options for shigellosis. The usual ESBLs seen are sulfhydryl variable (SHV-type; cefotaximases (CTX-M are very uncommonly detected. Here, we report a CTX-M type and AmpC-producing Shigella flexneri from a three-year-old boy residing in Central Kerala, South India.

  12. Comparative sequence analysis of acid sensitive/resistance proteins in Escherichia coli and Shigella flexneri

    Science.gov (United States)

    Manikandan, Selvaraj; Balaji, Seetharaaman; Kumar, Anil; Kumar, Rita

    2007-01-01

    The molecular basis for the survival of bacteria under extreme conditions in which growth is inhibited is a question of great current interest. A preliminary study was carried out to determine residue pattern conservation among the antiporters of enteric bacteria, responsible for extreme acid sensitivity especially in Escherichia coli and Shigella flexneri. Here we found the molecular evidence that proved the relationship between E. coli and S. flexneri. Multiple sequence alignment of the gadC coded acid sensitive antiporter showed many conserved residue patterns at regular intervals at the N-terminal region. It was observed that as the alignment approaches towards the C-terminal, the number of conserved residues decreases, indicating that the N-terminal region of this protein has much active role when compared to the carboxyl terminal. The motif, FHLVFFLLLGG, is well conserved within the entire gadC coded protein at the amino terminal. The motif is also partially conserved among other antiporters (which are not coded by gadC) but involved in acid sensitive/resistance mechanism. Phylogenetic cluster analysis proves the relationship of Escherichia coli and Shigella flexneri. The gadC coded proteins are converged as a clade and diverged from other antiporters belongs to the amino acid-polyamine-organocation (APC) superfamily. PMID:21670792

  13. Chromosomal and plasmid-encoded factors of Shigella flexneri induce secretogenic activity ex vivo.

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    Christina S Faherty

    Full Text Available Shigella flexneri is a Gram-negative, facultative intracellular pathogen that causes millions of cases of watery or bloody diarrhea annually, resulting in significant global mortality. Watery diarrhea is thought to arise in the jejunum, and subsequent bloody diarrhea occurs as a result of invasion of the colonic epithelium. Previous literature has demonstrated that Shigella encodes enterotoxins, both chromosomally and on the 220 kilobase virulence plasmid. The ShigellaEnterotoxins 1 and 2 (ShET1 and ShET2 have been shown to increase water accumulation in the rabbit ileal loop model. In addition, these toxins increase the short circuit current in rabbit tissue mounted in Ussing chambers, which is a model for the ion exchange that occurs during watery diarrhea. In this study, we sought to validate the use of mouse jejunum in Ussing chamber as an alternative, more versatile model to study bacterial pathogenesis. In the process, we also identified enterotoxins in addition to ShET1 and ShET2 encoded by S. flexneri. Through analysis of proteins secreted from wildtype bacteria and various deletion mutants, we have identified four factors responsible for enterotoxin activity: ShET1 and Pic, which are encoded on the chromosome; ShET2 (encoded by sen or ospD3, which requires the type-III secretion system for secretion; and SepA, an additional factor encoded on the virulence plasmid. The use of mouse jejunum serves as a reliable and reproducible model to identify the enterotoxins elaborated by enteric bacteria. Moreover, the identification of all Shigella proteins responsible for enterotoxin activity is vital to our understanding of Shigella pathogenicity and to our success in developing safe and effective vaccine candidates.

  14. Abortive Intestinal Infection With an Escherichia coli-Shigella flexneri Hybrid Strain

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    Formal, Samuel B.; LaBrec, E. H.; Kent, T. H.; Falkow, S.

    1965-01-01

    Formal, Samuel B., (Walter Reed Army Institute of Research, Washington, D.C.), E. H. LaBrec, T. H. Kent, and S. Falkow. Abortive intestinal infection with an Escherichia coli-Shigella flexneri hybrid strain. J. Bacteriol. 89:1374–1382. 1965.—The mechanism of the apparent loss of virulence of an Escherichia coli-Shigella flexneri hybrid strain was studied. The parent Shigella strain caused a fatal enteric infection when fed to starved guinea pigs, and signs of dysentery followed its oral administration to monkeys. The hybrid strain failed to produce any apparent symptoms when fed to either of these species. The parent strain was shown to invade the intestinal mucosa of starved guinea pigs. This caused a severe inflammatory reaction in the lamina propria, which progressed to ulceration of the intestinal epithelium and resulted in death of the animal. The hybrid strain also invaded the intestinal mucosa and produced an inflammatory reaction. In this case, the inflammatory reaction subsided, the intestine returned to normal within 4 days after challenge, and the animal survived. Both fluorescent-antibody techniques and in vivo growth studies have shown that the hybrid strain can not maintain itself in the intestinal mucosa. Preliminary studies have indicated that a similar situation also exists in the monkey. It is concluded that the virulence of dysentery bacilli rests not only in the capacity to reach the lamina propria, but also in the ability to multiply in this region. Images PMID:14293011

  15. Shigella flexneri-induced vaginitis in a prepubertal children: description of a case

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    Antonella Restelli

    2011-06-01

    Full Text Available In prepuberal girls vulvo-vaginitis are caused by germs of intestinal origin,mycetes, Gardnerella vaginalis, protozoa. Shigella is an uncommon agent able to induce valvovaginitis in children. We report the case of a 7-year-old girl with chronic vulvo-vaginitis caused by S. flexneri. Antibiotic Susceptibility Testing revealed that S. flexnery was sensible to cefotaxime, amoxicillin, imipenem, ciprofloxacin, but resistant to amikacin, cefazolin, gentamycin, ampicillin and tetracycline. A treatment with ciprofloxacin brought to a rapid resolution of all symptoms. At the follows up at 3 and 6 months the patient did not report symptoms of infection or articular cartilage abnormality; microbiological evaluations were also negative. Even if it is a single case report and other clinical trial may be performed in order to validate this hypothesis,we speculate that in patient with vulvo-vaginal infection living in environment with low hygiene care, a carefully microbiological evaluation of uncommon agents may be performed.

  16. Antimicrobial Resistance of Shigella flexneri Serotype 1b Isolates in China.

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    Xianyan Cui

    Full Text Available Shigella flexneri serotype 1b is among the most prominent serotypes in developing countries, followed by serotype 2a. However, only limited data is available on the global phenotypic and genotypic characteristics of S. flexneri 1b. In the present study, 40 S. flexneri 1b isolates from different regions of China were confirmed by serotyping and biochemical characterization. Antimicrobial susceptibility testing showed that 85% of these isolates were multidrug-resistant strains and antibiotic susceptibility profiles varied between geographical locations. Strains from Yunnan were far more resistant than those from Xinjiang, while only one strain from Shanghai was resistant to ceftazidime and aztreonam. Fifteen cephalosporin resistant isolates were identified in this study. ESBL genes (blaSHV, blaTEM, blaOXA, and blaCTX-M and ampC genes (blaMOX, blaFOX, blaMIR(ACT-1, blaDHA, blaCIT and blaACC were subsequently detected among the 15 isolates. The results showed that these strains were positive only for blaTEM, blaOXA, blaCTX-M, intI1, and intI2. Furthermore, pulsed-field gel electrophoresis (PFGE analysis showed that the 40 isolates formed different profiles, and the PFGE patterns of Xinjiang isolates were distinct from Yunnan and Shanghai isolates by one obvious, large, missing band. In summary, similarities in resistance patterns were observed in strains with the same PFGE pattern. Overall, the results supported the need for more prudent selection and use of antibiotics in China. We suggest that antibiotic susceptibility testing should be performed at the start of an outbreak, and antibiotic use should be restricted to severe Shigella cases, based on resistance pattern variations observed in different regions. The data obtained in the current study might help to develop a strategy for the treatment of infections caused by S. flexneri 1b in China.

  17. The common structural architecture of Shigella flexneri and Salmonella typhimurium type three secretion needles.

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    Jean-Philippe Demers

    2013-03-01

    Full Text Available The Type Three Secretion System (T3SS, or injectisome, is a macromolecular infection machinery present in many pathogenic Gram-negative bacteria. It consists of a basal body, anchored in both bacterial membranes, and a hollow needle through which effector proteins are delivered into the target host cell. Two different architectures of the T3SS needle have been previously proposed. First, an atomic model of the Salmonella typhimurium needle was generated from solid-state NMR data. The needle subunit protein, PrgI, comprises a rigid-extended N-terminal segment and a helix-loop-helix motif with the N-terminus located on the outside face of the needle. Second, a model of the Shigella flexneri needle was generated from a high-resolution 7.7-Å cryo-electron microscopy density map. The subunit protein, MxiH, contains an N-terminal α-helix, a loop, another α-helix, a 14-residue-long β-hairpin (Q51-Q64 and a C-terminal α-helix, with the N-terminus facing inward to the lumen of the needle. In the current study, we carried out solid-state NMR measurements of wild-type Shigella flexneri needles polymerized in vitro and identified the following secondary structure elements for MxiH: a rigid-extended N-terminal segment (S2-T11, an α-helix (L12-A38, a loop (E39-P44 and a C-terminal α-helix (Q45-R83. Using immunogold labeling in vitro and in vivo on functional needles, we located the N-terminus of MxiH subunits on the exterior of the assembly, consistent with evolutionary sequence conservation patterns and mutagenesis data. We generated a homology model of Shigella flexneri needles compatible with both experimental data: the MxiH solid-state NMR chemical shifts and the state-of-the-art cryoEM density map. These results corroborate the solid-state NMR structure previously solved for Salmonella typhimurium PrgI needles and establish that Shigella flexneri and Salmonella typhimurium subunit proteins adopt a conserved structure and orientation in their

  18. Vaccination with Shigella flexneri 2a conjugate induces type 2a and cross-reactive type 6 antibodies in humans but not in mice.

    Science.gov (United States)

    Farzam, Nahid; Ramon-Saraf, Reut; Banet-Levi, Yonit; Lerner-Geva, Liat; Ashkenazi, Shai; Kubler-Kielb, Joanna; Vinogradov, Evgeny; Robbins, John B; Schneerson, Rachel

    2017-09-05

    Shigella flexneri (S. flexneri) 6 has emerged as an important cause of shigellosis. Our efficacy study of Shigella sonnei and S. flexneri 2a O-specific polysaccharide (O-SP) conjugates in 1-4year-olds had too few S. flexneri 2a cases for efficacy evaluation but surprisingly showed protection of 3-4year-olds, S. flexneri 2a-recipients, from S. flexneri 6 infection. To investigate this cross-protection antibodies to both Shigella types were investigated in all sera remaining from previous studies. Twenty to 30% of 3-44year-old humans injected with S. flexneri 2a conjugate responded with ≥4-fold increases of IgG anti type 6, p<0.00001. The specificity of these antibodies was shown by inhibition studies. S. flexneri 6 infection of 2 children induced besides S. flexneri 6, also S. flexneri 2a antibodies, at levels of S. flexneri 2a vaccinees. S. flexneri 2a antibodies induced by S. flexneri 6 conjugates could not be studied since no such conjugate was assessed in humans and mice responded almost exclusively to the O-SP of the injected conjugate, with no cross-reactive antibodies. Our results indicate induction of cross-reactive protective antibodies. The O-acetylated disaccharide shared by S. flexneri 6 and 2a O-SPs, is the likely basis for their cross-reactivity. S. flexneri 6 O-SP conjugates, alone and in combination with S. flexneri 2a, merit further investigation for broad S. flexneri protection. Published by Elsevier Ltd.

  19. Dipstick for rapid diagnosis of Shigella flexneri 2a in stool.

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    Faridabano Nato

    2007-04-01

    Full Text Available Shigellosis or bacillary dysentery, an acute bloody diarrhoea, is a major public health burden in developing countries. In the absence of prompt and appropriate treatment, the infection is often fatal, particularly in young malnourished children. Here, we describe a new diagnostic test for rapid detection, in stool, at the bedside of patients, of Shigella flexneri 2a, the most predominant agent of the endemic form of the disease.The test is based on the detection of S.flexneri 2a lipopolysaccharide (LPS using serotype 2a-specific monoclonal antibodies coupled to gold particles and displayed on one-step immunochromatographic dipstick. A concentration as low as 20 ng/ml of LPS is detected in distilled water and in reconstituted stools in under 15 minutes. The threshold of detection corresponds to a concentration of 5x10(7 CFU/ml of S. flexneri 2a, which provides an unequivocal positive reaction in three minutes in distilled water and reconstituted stools. The specificity is 100% when tested with a battery of Shigella and unrelated strains, in culture. When tested in Vietnam, on clinical samples, the specificity and sensitivity were 99.2 and 91.5%, respectively. A decrease of the sensitivity during the evaluation on stool samples was observed after five weeks at room temperature and was due to moistening of the dipsticks caused by the humidity of the air during the fifth week of the evaluation. This drawback is now overcome by improving the packaging and providing dipsticks individually wrapped in waterproof bags.This simple dipstick-bases test represents a powerful tool for case management and epidemiological surveys.

  20. The Zebrafish as a New Model for the In Vivo Study of Shigella flexneri Interaction with Phagocytes and Bacterial Autophagy

    Science.gov (United States)

    Mostowy, Serge; Boucontet, Laurent; Mazon Moya, Maria J.; Sirianni, Andrea; Boudinot, Pierre; Hollinshead, Michael; Cossart, Pascale; Herbomel, Philippe; Levraud, Jean-Pierre; Colucci-Guyon, Emma

    2013-01-01

    Autophagy, an ancient and highly conserved intracellular degradation process, is viewed as a critical component of innate immunity because of its ability to deliver cytosolic bacteria to the lysosome. However, the role of bacterial autophagy in vivo remains poorly understood. The zebrafish (Danio rerio) has emerged as a vertebrate model for the study of infections because it is optically accessible at the larval stages when the innate immune system is already functional. Here, we have characterized the susceptibility of zebrafish larvae to Shigella flexneri, a paradigm for bacterial autophagy, and have used this model to study Shigella-phagocyte interactions in vivo. Depending on the dose, S. flexneri injected in zebrafish larvae were either cleared in a few days or resulted in a progressive and ultimately fatal infection. Using high resolution live imaging, we found that S. flexneri were rapidly engulfed by macrophages and neutrophils; moreover we discovered a scavenger role for neutrophils in eliminating infected dead macrophages and non-immune cell types that failed to control Shigella infection. We observed that intracellular S. flexneri could escape to the cytosol, induce septin caging and be targeted to autophagy in vivo. Depletion of p62 (sequestosome 1 or SQSTM1), an adaptor protein critical for bacterial autophagy in vitro, significantly increased bacterial burden and host susceptibility to infection. These results show the zebrafish larva as a new model for the study of S. flexneri interaction with phagocytes, and the manipulation of autophagy for anti-bacterial therapy in vivo. PMID:24039575

  1. HLA-B27M1M2 and high immune responsiveness to Shigella flexneri in post-dysenteric arthritis

    NARCIS (Netherlands)

    van Bohemen, C. G.; Nabbe, A. J.; Landheer, J. E.; Grumet, F. C.; Mazurkiewicz, E. S.; Dinant, H. J.; Lionarons, R. J.; van Bodegom, P. C.; Zanen, H. C.

    1986-01-01

    The heterogeneous HLA-B27 antigen is closely associated with post-infectious or reactive arthritis (ReA) and is comprised of two serologically defined variants: B27M1+M2+ and B27M1+M2-. An outbreak of dysentery (n = 120) caused by a Shigella flexneri 2a strain, which possessed cell envelope antigens

  2. Small-Molecule Inhibitor of the Shigella flexneri Master Virulence Regulator VirF

    Science.gov (United States)

    Koppolu, Veerendra; Osaka, Ichie; Skredenske, Jeff M.; Kettle, Bria; Hefty, P. Scott; Li, Jiaqin

    2013-01-01

    VirF is an AraC family transcriptional activator that is required for the expression of virulence genes associated with invasion and cell-to-cell spread by Shigella flexneri, including multiple components of the type three secretion system (T3SS) machinery and effectors. We tested a small-molecule compound, SE-1 (formerly designated OSSL_051168), which we had identified as an effective inhibitor of the AraC family proteins RhaS and RhaR, for its ability to inhibit VirF. Cell-based reporter gene assays with Escherichia coli and Shigella, as well as in vitro DNA binding assays with purified VirF, demonstrated that SE-1 inhibited DNA binding and transcription activation (likely by blocking DNA binding) by VirF. Analysis of mRNA levels using real-time quantitative reverse transcription-PCR (qRT-PCR) further demonstrated that SE-1 reduced the expression of the VirF-dependent virulence genes icsA, virB, icsB, and ipaB in Shigella. We also performed eukaryotic cell invasion assays and found that SE-1 reduced invasion by Shigella. The effect of SE-1 on invasion required preincubation of Shigella with SE-1, in agreement with the hypothesis that SE-1 inhibited the expression of VirF-activated genes required for the formation of the T3SS apparatus and invasion. We found that the same concentrations of SE-1 had no detectable effects on the growth or metabolism of the bacterial cells or the eukaryotic host cells, respectively, indicating that the inhibition of invasion was not due to general toxicity. Overall, SE-1 appears to inhibit transcription activation by VirF, exhibits selectivity toward AraC family proteins, and has the potential to be developed into a novel antibacterial agent. PMID:24002059

  3. Virulence and Stress Responses of Shigella flexneri Regulated by PhoP/PhoQ

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    Zhiwei Lin

    2018-01-01

    Full Text Available The two-component signal transduction system PhoP/PhoQ is an important regulator for stress responses and virulence in most Gram-negative bacteria, but characterization of PhoP/PhoQ in Shigella has not been thoroughly investigated. In the present study, we found that deletion of phoPQ (ΔphoPQ from Shigella flexneri 2a 301 (Sf301 resulted in a significant decline (reduced by more than 15-fold in invasion of HeLa cells and Caco-2 cells, and less inflammation (− or + compared to Sf301 (+++ in the guinea pig Sereny test. In low Mg2+ (10 μM medium or pH 5 medium, the ΔphoPQ strain exhibited a growth deficiency compared to Sf301. The ΔphoPQ strain was more sensitive than Sf301 to polymyxin B, an important antimicrobial agent for treating multi-resistant Gram-negative infections. By comparing the transcriptional profiles of ΔphoPQ and Sf301 using DNA microarrays, 117 differentially expressed genes (DEGs were identified, which were involved in Mg2+ transport, lipopolysaccharide modification, acid resistance, bacterial virulence, respiratory, and energy metabolism. Based on the reported PhoP box motif [(T/G GTTTA-5nt-(T/G GTTTA], we screened 38 suspected PhoP target operons in S. flexneri, and 11 of them (phoPQ, mgtA, slyB, yoaE, yrbL, icsA, yhiWX, rstA, hdeAB, pagP, and shf–rfbU-virK-msbB2 were demonstrated to be PhoP-regulated genes based on electrophoretic mobility shift assays and β-galactosidase assays. One of these PhoP-regulated genes, icsA, is a well-known virulence factor in S. flexneri. In conclusion, our data suggest that the PhoP/PhoQ system modulates S. flexneri virulence (in an icsA-dependent manner and stress responses of Mg2+, pH and antibacterial peptides.

  4. Facile preparation of disposable immunosensor for Shigella flexneri based on multi-wall carbon nanotubes/chitosan composite

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    Zhao Guangying, E-mail: zhaogy-user@163.co [Food Safety Key Lab of Zhejiang Province, Department of Food Quality and Safety, Zhejiang Gongshang University, 149, Jiaogong Road, Hangzhou 310035, Zhejiang Province (China); Zhan Xuejia [Food Safety Key Lab of Zhejiang Province, Department of Food Quality and Safety, Zhejiang Gongshang University, 149, Jiaogong Road, Hangzhou 310035, Zhejiang Province (China)

    2010-02-28

    Based on multi-wall carbon nanotubes (MWCNT)/chitosan/horseradish peroxidase labeled antibodies to Shigella flexneri (HRP-anti-S. flexneri) biocomposite film on a screen-printed electrode (SPE) surface, a disposable immunosensor has been developed for the rapid detection of S. flexneri. The HRP-anti-S. flexneri can be entrapped into MWCNT/chitosan composite matrix without other cross-linking agent. Thionine and H{sub 2}O{sub 2} were used as the mediator and substrate, respectively. The surface morphologies of modified films were characterized by atomic force microscope (AFM). Cyclic voltammery (CV) was carried out to characterize the electrochemical properties of the immobilization of materials on the electrode surface and quantified S. flexneri. Due to the strong electrocatalytic properties of MWCNT and HRP toward H{sub 2}O{sub 2}, the response signal was significantly amplified. S. flexneri could be detected by the decrease of the reduction peak current before and after immunoreaction. Under optimal conditions, S. flexneri could be detected in the range of 10{sup 4} to 10{sup 10} cfu mL{sup -1}, with a detection limit of 2.3 x 10{sup 3} cfu mL{sup -1} (S/N = 3). Furthermore, the proposed immunosensor exhibited a satisfactory specificity, reproducibility, stability and accuracy, indicating that the proposed immunosensor has potential application for a facile, rapid and harmless immunoassay.

  5. Facile preparation of disposable immunosensor for Shigella flexneri based on multi-wall carbon nanotubes/chitosan composite

    International Nuclear Information System (INIS)

    Zhao Guangying; Zhan Xuejia

    2010-01-01

    Based on multi-wall carbon nanotubes (MWCNT)/chitosan/horseradish peroxidase labeled antibodies to Shigella flexneri (HRP-anti-S. flexneri) biocomposite film on a screen-printed electrode (SPE) surface, a disposable immunosensor has been developed for the rapid detection of S. flexneri. The HRP-anti-S. flexneri can be entrapped into MWCNT/chitosan composite matrix without other cross-linking agent. Thionine and H 2 O 2 were used as the mediator and substrate, respectively. The surface morphologies of modified films were characterized by atomic force microscope (AFM). Cyclic voltammery (CV) was carried out to characterize the electrochemical properties of the immobilization of materials on the electrode surface and quantified S. flexneri. Due to the strong electrocatalytic properties of MWCNT and HRP toward H 2 O 2 , the response signal was significantly amplified. S. flexneri could be detected by the decrease of the reduction peak current before and after immunoreaction. Under optimal conditions, S. flexneri could be detected in the range of 10 4 to 10 10 cfu mL -1 , with a detection limit of 2.3 x 10 3 cfu mL -1 (S/N = 3). Furthermore, the proposed immunosensor exhibited a satisfactory specificity, reproducibility, stability and accuracy, indicating that the proposed immunosensor has potential application for a facile, rapid and harmless immunoassay.

  6. Identification of critical residues of the serotype modifying O-acetyltransferase of Shigella flexneri

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    Thanweer Farzaana

    2012-07-01

    Full Text Available Abstract Background Thirteen serotypes of Shigella flexneri (S. flexneri have been recognised, all of which are capable of causing bacillary dysentery or shigellosis. With the emergence of the newer S. flexneri serotypes, the development of an effective vaccine has only become more challenging. One of the factors responsible for the generation of serotype diversity is an LPS O-antigen modifying, integral membrane protein known as O-acetyltransferase or Oac. Oac functions by adding an acetyl group to a specific O-antigen sugar, thus changing the antigenic signature of the parent S. flexneri strain. Oac is a membrane protein, consisting of hydrophobic and hydrophilic components. Oac bears homology to several known and predicted acetyltransferases with most homology existing in the N-terminal transmembrane (TM regions. Results In this study, the conserved motifs in the TM regions and in hydrophilic loops of S. flexneri Oac were targeted for mutagenesis with the aim of identifying the amino acid residues essential for the function of Oac. We previously identified three critical arginines–R73, R75 and R76 in the cytoplasmic loop 3 of Oac. Re-establishing that these arginines are critical, in this study we suggest a catalytic role for R73 and a structural role for R75 and R76 in O-acetylation. Serine-glycine motifs (SG 52–53, GS 138–139 and SYG 274–276, phenylalanine-proline motifs (FP 78–79 and FPV 282–84 and a tryptophan-threonine motif (WT141-142 found in TM segments and residues RK 110–111, GR 269–270 and D333 found in hydrophilic loops were also found to be critical to Oac function. Conclusions By studying the effect of the mutations on Oac’s function and assembly, an insight into the possible roles played by the chosen amino acids in Oac was gained. The transmembrane serine-glycine motifs and hydrophilic residues (RK 110–111, GR 269–270 and D333 were shown to have an affect on Oac assembly which suggests a structural role

  7. The Shigella flexneri OmpA amino acid residues 188EVQ190 are essential for the interaction with the virulence factor PhoN2.

    Science.gov (United States)

    Scribano, Daniela; Damico, Rosanna; Ambrosi, Cecilia; Superti, Fabiana; Marazzato, Massimiliano; Conte, Maria Pia; Longhi, Catia; Palamara, Anna Teresa; Zagaglia, Carlo; Nicoletti, Mauro

    2016-12-01

    Shigella flexneri is an intracellular pathogen that deploys an arsenal of virulence factors promoting host cell invasion, intracellular multiplication and intra- and inter-cellular dissemination. We have previously reported that the interaction between apyrase (PhoN2), a periplasmic ATP-diphosphohydrolase, and the C-terminal domain of the outer membrane (OM) protein OmpA is likely required for proper IcsA exposition at the old bacterial pole and thus for full virulence expression of Shigella flexneri (Scribano et al., 2014). OmpA, that is the major OM protein of Gram-negative bacteria, is a multifaceted protein that plays many different roles both in the OM structural integrity and in the virulence of several pathogens. Here, by using yeast two-hybrid technology and by constructing an in silico 3D model of OmpA from S. flexneri 5a strain M90T, we observed that the OmpA residues 188 EVQ 190 are likely essential for PhoN2-OmpA interaction. The 188 EVQ 190 amino acids are located within a flexible region of the OmpA protein that could represent a scaffold for protein-protein interaction.

  8. Outer membrane protein A (OmpA: a new player in shigella flexneri protrusion formation and inter-cellular spreading.

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    Cecilia Ambrosi

    Full Text Available Outer membrane protein A (OmpA is a multifaceted predominant outer membrane protein of Escherichia coli and other Enterobacteriaceae whose role in the pathogenesis of various bacterial infections has recently been recognized. Here, the role of OmpA on the virulence of Shigella flexneri has been investigated. An ompA mutant of wild-type S. flexneri 5a strain M90T was constructed (strain HND92 and it was shown to be severely impaired in cell-to-cell spreading since it failed to plaque on HeLa cell monolayers. The lack of OmpA significantly reduced the levels of IcsA while the levels of cell associated and released IcsP-cleaved 95 kDa amino-terminal portion of the mature protein were similar. Nevertheless, the ompA mutant displayed IcsA exposed across the entire bacterial surface. Surprisingly, the ompA mutant produced proper F-actin comet tails, indicating that the aberrant IcsA exposition at bacterial lateral surface did not affect proper activation of actin-nucleating proteins, suggesting that the absence of OmpA likely unmasks mature or cell associated IcsA at bacterial lateral surface. Moreover, the ompA mutant was able to invade and to multiply within HeLa cell monolayers, although internalized bacteria were found to be entrapped within the host cell cytoplasm. We found that the ompA mutant produced significantly less protrusions than the wild-type strain, indicating that this defect could be responsible of its inability to plaque. Although we could not definitely rule out that the ompA mutation might exert pleiotropic effects on other S. flexneri genes, complementation of the ompA mutation with a recombinant plasmid carrying the S. flexneri ompA gene clearly indicated that a functional OmpA protein is required and sufficient for proper IcsA exposition, plaque and protrusion formation. Moreover, an independent ompA mutant was generated. Since we found that both mutants displayed identical virulence profile, these results further supported the

  9. Ongoing outbreak of Shigella flexneri serotype 3a in men who have sex with men in England and Wales, data from 2009-2011

    NARCIS (Netherlands)

    Borg, M.L.; Modi, A.; Tostmann, A.; Gobin, M.; Cartwright, J.; Quigley, C.; Crook, P.; Boxall, N.; Paul, J.; Cheasty, T.; Gill, N.; Hughes, G.; Simms, I.; Oliver, I.

    2012-01-01

    Diagnoses of Shigella flexneri in the United Kingdom (UK) are usually travel-related. However, since 2009, there has been an overall increase in UK-acquired cases. The Health Protection Agency has been investigating a national outbreak of S. flexneri detected in 2011 and which is still ongoing.

  10. Listeria monocytogenes and Shigella flexneri Activate the NLRP1B Inflammasome.

    Science.gov (United States)

    Neiman-Zenevich, Jana; Stuart, Sarah; Abdel-Nour, Mena; Girardin, Stephen E; Mogridge, Jeremy

    2017-11-01

    Activation of the innate immune receptor NLRP1B leads to the formation of an inflammasome, which induces autoproteolytic processing of pro-caspase-1, and ultimately to the release of inflammatory cytokines and to the execution of pyroptosis. One of the signals to which NLRP1B responds is metabolic stress that occurs in cells deprived of glucose or treated with metabolic inhibitors. NLRP1B might therefore sense microbial infection, as intracellular pathogens such as Listeria monocytogenes and Shigella flexneri cause metabolic stress as a result of nutrient scavenging and host cell damage. Here we addressed whether these pathogens activate the NLRP1B inflammasome. We found that Listeria infection activated the NLRP1B inflammasome in a reconstituted fibroblast model. Activation of NLRP1B by Listeria was diminished in an NLRP1B mutant shown previously to be defective at detecting energy stress and was dependent on the expression of listeriolysin O (LLO), a protein required for vacuolar escape. Infections of either Listeria or Shigella activated NLRP1B in the RAW264.7 murine macrophage line, which expresses endogenous NLRP1B. We conclude that NLRP1B senses cellular infection by distinct invasive pathogens. Copyright © 2017 American Society for Microbiology.

  11. Decontamination of tomato, red cabbage, carrot, fresh parsley and fresh green onion inoculated with Shigella sonnei and Shigella flexneri by some Essential oils (in vitro condition

    Directory of Open Access Journals (Sweden)

    Farhang Aliakbari

    2014-06-01

    Full Text Available Background: Essential oils and their major constituents are useful sources of antimicrobial compounds. There are a few reports on the decontamination and antimicrobial activity of essential oils towards Shigella spp.Materials and Methods: In this study, the antimicrobial and decontamination potentials of essential oils at different concentrations, belonging to plants such as Thymus vulgaris, Saturiea hortensis, Mentha polegium, Cuminum cyminum, Lavandula officinalis and Mentha viridis L. (spearmint, towards Shigella sonnei and Shigella  flexneri were investigated. The disk diffusion method demonstrated the antimicrobial potential of the essential oils.Results: The ability of essential oils to decontaminate vegetables such as, tomato, red cabbage, carrot, fresh parsley and fresh green onion that were previously inoculated with Shigella spp. was determined. Inhibitory effects of essential oils towards Shigella spp. were noted in the disk diffusion method. There was a reduction in Shigella population following inoculation of cultures with 0.5% and 0.1% (v/v essential oils.Conclusion: This study confirmed that essential oils have the potential to be used for decontamination of vegetables.

  12. Kefir-isolated bacteria and yeasts inhibit Shigella flexneri invasion and modulate pro-inflammatory response on intestinal epithelial cells.

    Science.gov (United States)

    Bolla, P A; Abraham, A G; Pérez, P F; de Los Angeles Serradell, M

    2016-02-01

    The aim of this work was to evaluate the ability of a kefir-isolated microbial mixture containing three bacterial and two yeast strains (MM) to protect intestinal epithelial cells against Shigella flexneri invasion, as well as to analyse the effect on pro-inflammatory response elicited by this pathogen. A significant decrease in S. flexneri strain 72 invasion was observed on both HT-29 and Caco-2 cells pre-incubated with MM. Pre-incubation with the individual strains Saccharomyces cerevisiae CIDCA 8112 or Lactococcus lactis subsp. lactis CIDCA 8221 also reduced the internalisation of S. flexneri into HT-29 cells although in a lesser extent than MM. Interestingly, Lactobacillus plantarum CIDCA 83114 exerted a protective effect on the invasion of Caco-2 and HT-29 cells by S. flexneri. Regarding the pro-inflammatory response on HT-29 cells, S. flexneri infection induced a significant activation of the expression of interleukin 8 (IL-8), chemokine (C-C motif) ligand 20 (CCL20) and tumour necrosis factor alpha (TNF-α) encoding genes (P<0.05), whereas incubation of cells with MM did not induce the expression of any of the mediators assessed. Interestingly, pre-incubation of HT-29 monolayer with MM produced an inhibition of S. flexneri-induced IL-8, CCL20 and TNF-α mRNA expression. In order to gain insight on the effect of MM (or the individual strains) on this pro-inflammatory response, a series of experiments using a HT-29-NF-κB-hrGFP reporter system were performed. Pre-incubation of HT-29-NF-κB-hrGFP cells with MM significantly dampened Shigella-induced activation. Our results showed that the contribution of yeast strain Kluyveromyces marxianus CIDCA 8154 seems to be crucial in the observed effect. In conclusion, results presented in this study demonstrate that pre-treatment with a microbial mixture containing bacteria and yeasts isolated from kefir, resulted in inhibition of S. flexneri internalisation into human intestinal epithelial cells, along with the

  13. Topological characterisation and identification of critical domains within glucosyltransferase IV (GtrIV of Shigella flexneri

    Directory of Open Access Journals (Sweden)

    Nair Anesh

    2011-12-01

    Full Text Available Abstract Background The three bacteriophage genes gtrA, gtrB and gtr(type are responsible for O-antigen glucosylation in Shigella flexneri. Both gtrA and gtrB have been demonstrated to be highly conserved and interchangeable among serotypes while gtr(type was found to be specific to each serotype, leading to the hypothesis that the Gtr(type proteins are responsible for attaching glucosyl groups to the O-antigen in a site- and serotype- specific manner. Based on the confirmed topologies of GtrI, GtrII and GtrV, such interaction and attachment of the glucosyl groups to the O-antigen has been postulated to occur in the periplasm. Results In this study, the topology of GtrIV was experimentally determined by creating different fusions between GtrIV and a dual-reporter protein, PhoA/LacZ. This study shows that GtrIV consists of 8 transmembrane helices, 2 large periplasmic loops, 2 small cytoplasmic N- and C- terminal ends and a re-entrant loop that occurs between transmembrane helices III and IV. Though this topology differs from that of GtrI, GtrII, GtrV and GtrX, it is very similar to that of GtrIc. Furthermore, both the N-terminal periplasmic and the C-terminal periplasmic loops are important for GtrIV function as shown via a series of loop deletion experiments and the creation of chimeric proteins between GtrIV and its closest structural homologue, GtrIc. Conclusion The current study provides the basis for elucidating the structure and mechanism of action of this important O-antigen modifying glucosyltransferase.

  14. Common changes in global gene expression induced by RNA polymerase inhibitors in Shigella flexneri.

    Directory of Open Access Journals (Sweden)

    Hua Fu

    Full Text Available Characterization of expression profile of organisms in response to antimicrobials provides important information on the potential mechanism of action of the drugs. The special expression signature can be used to predict whether other drugs act on the same target. Here, the common response of Shigella flexneri to two inhibitors of RNA polymerase was examined using gene expression profiling. Consistent with similar effects of the two drugs, the gene expression profiles indicated that responses of the bacteria to these drugs were roughly the same, with 225 genes affected commonly. Of them, 88 were induced and 137 were repressed. Real-time PCR was performed for selected genes to verify the microarray results. Analysis of the expression data revealed that more than 30% of the plasmid-encoded genes on the array were up-regulated by the antibiotics including virF regulon, other virulence-related genes, and genes responsible for plasmid replication, maintenance, and transfer. In addition, some chromosome-encoded genes involved in virulence and genes acquired from horizontal transfer were also significantly up-regulated. However, the expression of genes encoding the beta-subunit of RNA polymerase was increased moderately. The repressed genes include those that code for products associated with the ribosome, citrate cycle, glycolysis, thiamine biosynthesis, purine metabolism, fructose metabolism, mannose metabolism, and cold shock proteins. This study demonstrates that the two antibiotics induce rapid cessation of RNA synthesis resulting in inhibition of translation components. It also indicates that the production of virulence factors involved in intercellular dissemination, tissue invasion and inflammatory destruction may be enhanced through derepressing horizontal transfer genes by the drugs.

  15. Theoretical conformational analysis of the tetrasaccharide repeating units of the O-antigenic polysaccharide of Shigella flexneri

    International Nuclear Information System (INIS)

    Lipkind, G.M.; Kochetkov, N.K.

    1986-01-01

    A theoretical conformational analysis has been made of the four tetrasaccharide repeating units of the polysaccharide of Shigella flexneri, serotype Y. The interdependence of the conformation states of the neighboring disaccharide units and the oligosaccharides has been investigated. The distribution of the tetrasaccharides over the conformations in solution obtained by calculating the free energies of the optimum structures is given. It has been shown that a substantial correction of the results relating to oligosaccharide chains is achieved when the entropy factors is taken into account

  16. Epidemiological characterization of resistance and PCR typing of Shigella flexneri and Shigella sonnei strains isolated from bacillary dysentery cases in Southeast Brazil

    Directory of Open Access Journals (Sweden)

    M.P.A. Penatti

    2007-02-01

    Full Text Available Shigella spp are Gram-negative, anaerobic facultative, non-motile, and non-sporulated bacilli of the Enterobacteriaceae family responsible for "Shigellosis" or bacillary dysentery, an important cause of worldwide morbidity and mortality. However, despite this, there are very few epidemiological studies about this bacterium in Brazil. We studied the antibiotic resistance profiles and the clonal structure of 60 Shigella strains (30 S. flexneri and 30 S. sonnei isolated from shigellosis cases in different cities within the metropolitan area of Campinas, State of São Paulo, Brazil. We used the following well-characterized molecular techniques: enterobacterial repetitive intergenic consensus, repetitive extragenic palindromic, and double-repetitive element-polymerase chain reaction to characterize the bacteria. Also, the antibiotic resistance of the strains was determined by the diffusion disk method. Many strains of S. flexneri and S. sonnei were found to be multi-resistant. S. flexneri strains were resistant to ampicillin in 83.3% of cases, chloramphenicol in 70.0%, streptomycin in 86.7%, sulfamethoxazole in 80.0%, and tetracycline in 80.0%, while a smaller number of strains were resistant to cephalothin (3.3% and sulfazotrim (10.0%. S. sonnei strains were mainly resistant to sulfamethoxazole (100.0% and tetracycline (96.7% and, to a lesser extent, to ampicillin (6.7% and streptomycin (26.7%. Polymerase chain reaction-based typing supported the existence of specific clones responsible for the shigellosis cases in the different cities and there was evidence of transmission between cities. This clonal structure would probably be the result of selection for virulence and resistance phenotypes. These data indicate that the human sanitary conditions of the cities investigated should be improved.

  17. Preparation, crystallization and preliminary X-ray crystallographic studies of diadenosine tetraphosphate hydrolase from Shigella flexneri 2a

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Wenxin; Wang, Qihai; Bi, Ruchang, E-mail: rcbi@sun5.ibp.ac.cn [Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Chaoyang District, Beijing 100101 (China)

    2005-12-01

    The 31.3 kDa Ap{sub 4}A hydrolase from Shigella flexneri 2a has been cloned, expressed and purified using an Escherichia coli expression system. Crystals of Ap{sub 4}A hydrolase have been obtained by the hanging-drop technique at 291 K using PEG 550 MME as precipitant. Diadenosine tetraphosphate (Ap{sub 4}A) hydrolase (EC 3.6.1.41) hydrolyzes Ap{sub 4}A symmetrically in prokaryotes. It plays a potential role in organisms by regulating the concentration of Ap{sub 4}A in vivo. To date, no three-dimensional structures of proteins with significant sequence homology to this protein have been determined. The 31.3 kDa Ap{sub 4}A hydrolase from Shigella flexneri 2a has been cloned, expressed and purified using an Escherichia coli expression system. Crystals of Ap{sub 4}A hydrolase have been obtained by the hanging-drop technique at 291 K using PEG 550 MME as precipitant. Ap{sub 4}A hydrolase crystals diffract X-rays to 3.26 Å and belong to space group P2{sub 1}, with unit-cell parameters a = 118.9, b = 54.6, c = 128.5 Å, β = 95.7°.

  18. A Novel Small RNA Regulates Tolerance and Virulence in Shigella flexneri by Responding to Acidic Environmental Changes

    Directory of Open Access Journals (Sweden)

    Ligui eWang

    2016-03-01

    Full Text Available Shigella flexneri is an important cause of bacillary dysentery in developing countries. Small regulatory RNAs (sRNAs play essential roles in diverse cellular processes. We found a novel sRNA Ssr1 based on RT-PCR, northern blot, and 5´RACE in S. flexneri. Ssr1 responds to acidic environmental changes, as shown by a strong linear correlation between the pH value and Ssr1 expression (R = 0.785, P < 0.05 using the qRT-PCR method. Deletion of Ssr1 results in growth retardation at pH values ranging from 5.0 to 7.0 (P < 0.05, and the survival rate was reduced by 22% in acidic conditions (pH 3.0. Additionally, virulence was significantly increased in an Ssr1 mutant strain, as revealed in a murine lung invasion model and survival model assays. By using the sTarPicker method and proteomic analysis, we considered that DnaK, which is a major factor that confers acidic stress tolerance, may be a direct target of Ssr1. We also found that Ssr1 may enhance virulence by directly targeting OmpA; this leads to altered expression of genes in the type three secretion system. This work provides new insight into the mechanism of adaptation to environmental stress and into the pathogenesis of Shigella.

  19. A novel plasmid-encoded serotype conversion mechanism through addition of phosphoethanolamine to the O-antigen of Shigella flexneri.

    Directory of Open Access Journals (Sweden)

    Qiangzheng Sun

    Full Text Available Shigella flexneri is the major pathogen causing bacillary dysentery in developing countries. S. flexneri is divided into at least 16 serotypes based on the combination of antigenic determinants present in the O-antigen. All the serotypes (except for serotype 6 share a basic O-unit containing one N-acetyl-d-glucosamine and three l-rhamnose residues, whereas differences between the serotypes are conferred by phage-encoded glucosylation and/or O-acetylation. Serotype Xv is a newly emerged and the most prevalent serotype in China, which can agglutinate with both MASF IV-1 and 7,8 monoclonal antibodies. The factor responsible for the presence of MASF IV-1 (E1037 epitope has not yet been identified. In this study, we analyzed the LPS structure of serotype Xv strains and found that the MASF IV-1 positive phenotype depends on an O-antigen modification with a phosphoethanolamine (PEtN group attached at position 3 of one of the rhamnose residues. A plasmid carried gene, lpt-O (LPS phosphoethanolamine transferase for O-antigen, mediates the addition of PEtN for serotype Xv and other MASF IV-1 positive strains. These findings reveal a novel serotype conversion mechanism in S. flexneri and show the necessity of further extension of the serotype classification scheme recognizing the MASF IV-1 positive strains as distinctive subtypes.

  20. Export of the Virulence Factors from Shigella Flexneri and Characterization of the mxi loci

    Science.gov (United States)

    1992-07-20

    studied in a monkey model for Shigella infection. The in vitro assays just described have been routinely used to closely examine each of the steps in...to Shigella protein antigens in Rhesus monkeys and humans infected with Shigella spp. Infect. Immun_ 53:57-63. Oaks, E. V. , and K. R. Turbyfill...thesis manuscript ent itled: ~Export of Virulence Faclors from Shigella f/exneri and characterization of the mxi loci. ~ beyond brief excerpts is

  1. Effect of x-ray treatments on Escherichia coli O157:H7, Listeria monocytogenes, Shigella flexneri, Salmonella enterica and inherent microbiota on whole mangoes

    Science.gov (United States)

    The aims of this investigation were to; (i) study the effect of X-ray treatments in reducing Escherichia coli O157:H7, Listeria monocytogenes, Salmonella enterica and Shigella flexneri on whole mangoes, and (ii) study the effect of Xray treatments on microflora counts (mesophilic counts, psychrotrop...

  2. Crystal Structure of the VapBC Toxin–Antitoxin Complex from Shigella flexneri Reveals a Hetero-Octameric DNA-Binding Assembly

    DEFF Research Database (Denmark)

    Dienemann, Christian; Bøggild, Andreas; Winther, Kristoffer S.

    2011-01-01

    the crystal structure of the intact Shigella flexneri VapBC TA complex, determined to 2.7 Å resolution. Both in solution and in the crystal structure, four molecules of each protein combine to form a large and globular hetero-octameric assembly with SpoVT/AbrB-type DNA-binding domains at each end and a total...

  3. Effect of X-ray treatments on Escherichia coli 0157:H7, Listeria monocytogenes, Shigella flexneri, Salmonella enterica and inherent microbiota on whole mangoes

    Science.gov (United States)

    The aims of this investigation were to; (i) study the effect of X-ray treatments in reducing Escherichia coli O157:H7, Listeria monocytogenes, Salmonella enterica and Shigella flexneri on whole mangoes, and (ii) study the effect of Xray treatments on microflora counts (mesophilic counts, psychrotrop...

  4. Safety and Immunogenicity of a Shigella flexneri 2a Invaplex 50 Intranasal Vaccine in Adult Volunteers

    Science.gov (United States)

    2010-06-01

    Scandjlnfect Dis 1993;25(5):569-77. [11] Oaks EV, Hale TL. Formal SB. Serum immune response to Shigella protein ami- gens in rhesus monkeys and humans...infection with virulent Shigellaflexneri 2a on the resistance of monkeys to subsequent infection with Shigella sonnei. J Infect Dis 1991; 164(September...july 2010 Keywords: Shigella jlexneri lnvaplex Nasal vaccine Shigellosis is a leading cause of diarrhea worldwide prompting vaccine development

  5. Genesis of a novel Shigella flexneri serotype by sequential infection of serotype-converting bacteriophages SfX and SfI

    Directory of Open Access Journals (Sweden)

    Sun Qiangzheng

    2011-12-01

    Full Text Available Abstract Background Shigella flexneri is the major pathogen causing bacillary dysentery. Fifteen serotypes have been recognized up to now. The genesis of new S. flexneri serotypes is commonly mediated by serotype-converting bacteriophages. Untypeable or novel serotypes from natural infections had been reported worldwide but have not been generated in laboratory. Results A new S. flexneri serotype-serotype 1 d was generated when a S. flexneri serotype Y strain (native LPS was sequentially infected with 2 serotype-converting bacteriophages, SfX first and then SfI. The new serotype 1 d strain agglutinated with both serotype X-specific anti-7;8 grouping serum and serotype 1a-specific anti- I typing serum, and differed from subserotypes 1a, 1b and 1c. Twenty four S. flexneri clinical isolates of serotype X were all converted to serotype 1 d by infection with phage SfI. PCR and sequencing revealed that SfI and SfX were integrated in tandem into the proA-yaiC region of the host chromosome. Conclusions These findings suggest a new S. flexneri serotype could be created in nature. Such a conversion may be constrained by susceptibility of a strain to infection by a given serotype-converting bacteriophage. This finding has significant implications in the emergence of new S. flexneri serotypes in nature.

  6. Overexpression, purification, characterization and preliminary crystallographic study of phosphoglycolate phosphatase from Shigella flexneri 2a strain 301

    International Nuclear Information System (INIS)

    Liu, Heli; Zhou, Huina; Zhu, Deyu; Bi, Ruchang

    2008-01-01

    Recombinant phosphoglycolate phosphatase from S. flexneri was overexpressed, purified, characterized and crystallized using the hanging-drop vapour-diffusion method. SeMet-labelled protein was also prepared and was crystallized for phase determination using the MAD technique. Phosphoglycolate phosphatase has a salvage function in the metabolism of the 2-phosphoglycolate formed during bacterial DNA repair. In order to better understand its dimerization behaviour, the influence of metal ions on its activity and its catalytic mechanism at the molecular level, recombinant phosphoglycolate phosphatase from Shigella flexneri was overexpressed, purified, characterized and crystallized by the hanging-drop vapour-diffusion method at 291 K using polyethylene glycol 3500 as a precipitant and zinc acetate as an additive. The crystals belonged to space group R3, with unit-cell parameters a = 88.1, b = 88.1, c = 259.2 Å, corresponding to the presence of two molecules in the asymmetric unit. SeMet-labelled protein was also prepared and crystallized for use in phase determination. Initial structure determination using the multiwavelength anomalous dispersion (MAD) method clearly revealed that SfPGPase bears an α-helical cap domain that differs from that of a previously reported orthologue

  7. The periplasmic enzyme, AnsB, of Shigella flexneri modulates bacterial adherence to host epithelial cells.

    Directory of Open Access Journals (Sweden)

    Divya T George

    Full Text Available S. flexneri strains, most frequently linked with endemic outbreaks of shigellosis, invade the colonic and rectal epithelium of their host and cause severe tissue damage. Here we have attempted to elucidate the contribution of the periplasmic enzyme, L-asparaginase (AnsB to the pathogenesis of S. flexneri. Using a reverse genetic approach we found that ansB mutants showed reduced adherence to epithelial cells in vitro and attenuation in two in vivo models of shigellosis, the Caenorhabditis elegans and the murine pulmonary model. To investigate how AnsB affects bacterial adherence, we compared the proteomes of the ansB mutant with its wild type parental strain using two dimensional differential in-gel electrophoresis and identified the outer membrane protein, OmpA as up-regulated in ansB mutant cells. Bacterial OmpA, is a prominent outer membrane protein whose activity has been found to be required for bacterial pathogenesis. Overexpression of OmpA in wild type S. flexneri serotype 3b resulted in decreasing the adherence of this virulent strain, suggesting that the up-regulation of OmpA in ansB mutants contributes to the reduced adherence of this mutant strain. The data presented here is the first report that links the metabolic enzyme AnsB to S. flexneri pathogenesis.

  8. Spa47 is an oligomerization-activated type three secretion system (T3SS) ATPase from Shigella flexneri.

    Science.gov (United States)

    Burgess, Jamie L; Jones, Heather B; Kumar, Prashant; Toth, Ronald T; Middaugh, C Russell; Antony, Edwin; Dickenson, Nicholas E

    2016-05-01

    Gram-negative pathogens often use conserved type three secretion systems (T3SS) for virulence. The Shigella type three secretion apparatus (T3SA) penetrates the host cell membrane and provides a unidirectional conduit for injection of effectors into host cells. The protein Spa47 localizes to the base of the apparatus and is speculated to be an ATPase that provides the energy for T3SA formation and secretion. Here, we developed an expression and purification protocol, producing active Spa47 and providing the first direct evidence that Spa47 is a bona fide ATPase. Additionally, size exclusion chromatography and analytical ultracentrifugation identified multiple oligomeric species of Spa47 with the largest greater than 8 fold more active for ATP hydrolysis than the monomer. An ATPase inactive Spa47 point mutant was then engineered by targeting a conserved Lysine within the predicted Walker A motif of Spa47. Interestingly, the mutant maintained a similar oligomerization pattern as active Spa47, but was unable to restore invasion phenotype when used to complement a spa47 null S. flexneri strain. Together, these results identify Spa47 as a Shigella T3SS ATPase and suggest that its activity is linked to oligomerization, perhaps as a regulatory mechanism as seen in some related pathogens. Additionally, Spa47 catalyzed ATP hydrolysis appears to be essential for host cell invasion, providing a strong platform for additional studies dissecting its role in virulence and providing an attractive target for anti-infective agents. © 2016 The Protein Society.

  9. Molecular epidemiology of Shigella flexneri in a long-stay psychiatric nursing center during 2001 to 2003.

    Science.gov (United States)

    Lee, Yeong-Sheng; Liu, Ming-Ching; Ko, Ching-Fen; Lu, Cheng-Hsiung; Tseng, Yi-Hsiung

    2005-03-01

    With six separate wards accommodating more than 1,600 patients, V Nursing Center (VNC) is a long-stay psychiatric nursing center in eastern Taiwan. During 2001 to 2003, 39 shigellosis cases occurred in VNC. Different from the notion that most cases of shigellosis are caused by Shigella sonnei, all except one of these cases were caused by S. flexneri, with the remaining one caused by an S. sonnei isolate. O-antigen serotyping showed that the 38 S. flexneri strains were of either type 1a (n = 20) or 4a (n = 18), two less prevalent serotypes in Taiwan. NotI-based pulsed-field gel electrophoresis analyses performed with 8 type 1a non-VNC strains and 9 type 4a non-VNC strains isolated from 1996 to 2003 for comparison divided the 28 type 1a strains and the 27 type 4a strains into 7 and 10 subtypes, designated subtypes P1A to P1G and subtypes P4A to P4J, respectively. Subtypes P1A and P4A, which appeared in three consecutive years in VNC as well as outside of VNC, are the most prevalent subtypes. Analyses of the relatedness of the VNC strains on the basis of the banding patterns grouped the type 1a and 4a strains into four and five clusters, respectively. All except one of the type 1a strains had 95% similarity, indicating that they had a common parent, whereas the type 4a strains had similarities that ranged from 77 to 93%, suggesting that they were of diverse origins. In two of the outbreaks, less related subtypes of the type 4a strains were found in the same VNC wards in consecutive years, suggesting the possible existence of different subtypes in VNC all the time. Antibiotic susceptibility testing showed that all except one of the S. flexneri strains were sensitive to at least seven antibiotics; the remaining isolate was sensitive to three antibiotics. The data from the latter tests should be helpful for selection of proper treatments for S. flexneri infections in Taiwan.

  10. Genome sequence of Shigella flexneri strain SP1, a diarrheal isolate that encodes an extended-spectrum β-lactamase (ESBL).

    Science.gov (United States)

    Shen, Ping; Fan, Jianzhong; Guo, Lihua; Li, Jiahua; Li, Ang; Zhang, Jing; Ying, Chaoqun; Ji, Jinru; Xu, Hao; Zheng, Beiwen; Xiao, Yonghong

    2017-05-12

    Shigellosis is the most common cause of gastrointestinal infections in developing countries. In China, the species most frequently responsible for shigellosis is Shigella flexneri. S. flexneri remains largely unexplored from a genomic standpoint and is still described using a vocabulary based on biochemical and serological properties. Moreover, increasing numbers of ESBL-producing Shigella strains have been isolated from clinical samples. Despite this, only a few cases of ESBL-producing Shigella have been described in China. Therefore, a better understanding of ESBL-producing Shigella from a genomic standpoint is required. In this study, a S. flexneri type 1a isolate SP1 harboring bla CTX-M-14 , which was recovered from the patient with diarrhea, was subjected to whole genome sequencing. The draft genome assembly of S. flexneri strain SP1 consisted of 4,592,345 bp with a G+C content of 50.46%. RAST analysis revealed the genome contained 4798 coding sequences (CDSs) and 100 RNA-encoding genes. We detected one incomplete prophage and six candidate CRISPR loci in the genome. In vitro antimicrobial susceptibility testing demonstrated that strain SP1 is resistant to ampicillin, amoxicillin/clavulanic acid, cefazolin, ceftriaxone and trimethoprim. In silico analysis detected genes mediating resistance to aminoglycosides, β-lactams, phenicol, tetracycline, sulphonamides, and trimethoprim. The bla CTX-M-14 gene was located on an IncFII2 plasmid. A series of virulence factors were identified in the genome. In this study, we report the whole genome sequence of a bla CTX-M-14 -encoding S. flexneri strain SP1. Dozens of resistance determinants were detected in the genome and may be responsible for the multidrug-resistance of this strain, although further confirmation studies are warranted. Numerous virulence factors identified in the strain suggest that isolate SP1 is potential pathogenic. The availability of the genome sequence and comparative analysis with other S

  11. Detection of Cytosolic Shigella flexneri via a C-Terminal Triple-Arginine Motif of GBP1 Inhibits Actin-Based Motility

    Directory of Open Access Journals (Sweden)

    Anthony S. Piro

    2017-12-01

    Full Text Available Dynamin-like guanylate binding proteins (GBPs are gamma interferon (IFN-γ-inducible host defense proteins that can associate with cytosol-invading bacterial pathogens. Mouse GBPs promote the lytic destruction of targeted bacteria in the host cell cytosol, but the antimicrobial function of human GBPs and the mechanism by which these proteins associate with cytosolic bacteria are poorly understood. Here, we demonstrate that human GBP1 is unique among the seven human GBP paralogs in its ability to associate with at least two cytosolic Gram-negative bacteria, Burkholderia thailandensis and Shigella flexneri. Rough lipopolysaccharide (LPS mutants of S. flexneri colocalize with GBP1 less frequently than wild-type S. flexneri does, suggesting that host recognition of O antigen promotes GBP1 targeting to Gram-negative bacteria. The targeting of GBP1 to cytosolic bacteria, via a unique triple-arginine motif present in its C terminus, promotes the corecruitment of four additional GBP paralogs (GBP2, GBP3, GBP4, and GBP6. GBP1-decorated Shigella organisms replicate but fail to form actin tails, leading to their intracellular aggregation. Consequentially, the wild type but not the triple-arginine GBP1 mutant restricts S. flexneri cell-to-cell spread. Furthermore, human-adapted S. flexneri, through the action of one its secreted effectors, IpaH9.8, is more resistant to GBP1 targeting than the non-human-adapted bacillus B. thailandensis. These studies reveal that human GBP1 uniquely functions as an intracellular “glue trap,” inhibiting the cytosolic movement of normally actin-propelled Gram-negative bacteria. In response to this powerful human defense program, S. flexneri has evolved an effective counterdefense to restrict GBP1 recruitment.

  12. Expression of bacterial virulence factors and cytokines during in vitro macrophage infection by enteroinvasive Escherichia coli and Shigella flexneri: a comparative study

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    Silvia Y Bando

    2010-09-01

    Full Text Available Enteroinvasive Escherichia coli (EIEC and Shigellaspp cause bacillary dysentery in humans by invading and multiplying within epithelial cells of the colonic mucosa. Although EIEC and Shigellashare many genetic and biochemical similarities, the illness caused by Shigellais more severe. Thus, genomic and structure-function molecular studies on the biological interactions of these invasive enterobacteria with eukaryotic cells have focused on Shigella rather than EIEC. Here we comparatively studied the interactions of EIEC and of Shigella flexneriwith cultured J774 macrophage-like cells. We evaluated several phenotypes: (i bacterial escape from macrophages after phagocytosis, (ii macrophage death induced by EIEC and S. flexneri, (iii macrophage cytokine expression in response to infection and (iv expression of plasmidial (pINV virulence genes. The results showed thatS. flexneri caused macrophage killing earlier and more intensely than EIEC. Both pathogens induced significant macrophage production of TNF, IL-1 and IL-10 after 7 h of infection. Transcription levels of the gene invasion plasmid antigen-C were lower in EIEC than in S. flexneri throughout the course of the infection; this could explain the diminished virulence of EIEC compared to S. flexneri.

  13. Behavior of Salmonella Typhimurium, Staphylococcus aureus, Listeria monocytogenes, and Shigella flexneri and Shigella sonnei during production of pulque, a traditional Mexican beverage.

    Science.gov (United States)

    Gómez-Aldapa, Carlos A; Díaz-Cruz, Claudio A; Villarruel-López, Angélica; Torres-Vitela, M del Refugio; Añorve-Morga, Javier; Rangel-Vargas, Esmeralda; Cerna-Cortes, Jorge F; Vigueras-Ramírez, J Gabriel; Castro-Rosas, Javier

    2011-04-01

    Pulque is a typical fermented alcoholic beverage of central Mexico, produced from the nectar of maguey agave plants. Production systems are largely artisanal, with inadequate hygiene conditions and exposure to multiple contamination sources. No data exist on pulque microbiological safety and the behavior of pathogenic microorganisms in agave nectar and pulque. An initial trial was done of the behavior of Salmonella Typhimurium, Staphylococcus aureus, Listeria monocytogenes, and Shigella flexneri and Shigella sonnei during fermentation of nectar from a single producer, nectar mixture from different producers, and seed pulque. A second trial simulating artisanal pulque production was done by contaminating fresh nectar with each of the five strains, storing at 22°C for 14 h, adding seed pulque, and fermenting until pulque was formed. During incubation at 16 or 22°C in the first trial, all the pathogenic strains multiplied in both the single producer nectar and the nectar mixture, reaching maximum concentrations at 12 h. Strains concentration then decreased slowly. In the seed pulque, the strains did not multiply and tended to die. In the second trial, all strains increased concentration from 0.7 to 1.6 log at 22°C, and from 0.5 to 1.1 at 16°C in the first 14 h. After addition of seed pulque, they were quickly deactivated until none was detected in the final product. The results suggest that the potential risk to consumers of contracting any of the five tested pathogenic bacterial strains from pulque is low.

  14. Shigellosis Caused by CTX-M Type ESBL Producing Shigella flexneri in Two Siblings of Rural Nepal: First Case Report from the Country

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    Narayan Prasad Parajuli

    2017-01-01

    Full Text Available Shigellosis is an acute infectious disease characterized as severe bloody diarrhea (dysentery and is accountable for a significant burden of morbidity and mortality especially in children under the age of 5 years. Antimicrobial therapy is required in the cases of severe dysentery associated with Shigella. However, emergence of multidrug resistant (MDR strains of Shigella spp. over the last two decades has restricted the use of common therapeutic antimicrobials. In MDR strains, the third-generation cephalosporins have been used for the treatment, but, unfortunately, emerging reports of enzyme mediated β-lactam resistance among Shigella isolates from various parts of the world have greatly compromised the therapy of pediatric dysentery. In Nepal, drug resistant strains of Shigella spp. have been reported, but MDR and extended spectrum β-lactamase (ESBL producing strains were previously unknown. Here, we report two Shigella flexneri isolates harboring ESBL genotype-CTX-M associated with acute dysentery in two siblings which were presented and treated in a tertiary care teaching hospital of Kathmandu, Nepal.

  15. The immunogenic SigA enterotoxin of Shigella flexneri 2a binds to HEp-2 cells and induces fodrin redistribution in intoxicated epithelial cells.

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    Keith Al-Hasani

    Full Text Available BACKGROUND: We have previously shown that the enterotoxin SigA which resides on the she pathogenicity island (PAI of S. flexneri 2a is an autonomously secreted serine protease capable of degrading casein. We have also demonstrated that SigA is cytopathic for HEp-2 cells and plays a role in the intestinal fluid accumulation associated with S. flexneri infections. METHODS/PRINCIPAL FINDINGS: In this work we show that SigA binds specifically to HEp-2 cells and degrades recombinant human alphaII spectrin (alpha-fodrin in vitro, suggesting that the cytotoxic and enterotoxic effects mediated by SigA are likely associated with the degradation of epithelial fodrin. Consistent with our data, this study also demonstrates that SigA cleaves intracellular fodrin in situ, causing its redistribution within cells. These results strongly implicate SigA in altering the cytoskeleton during the pathogenesis of shigellosis. On the basis of these findings, cleavage of fodrin is a novel mechanism of cellular intoxication for a Shigella toxin. Furthermore, information regarding immunogenicity to SigA in infected patients is lacking. We studied the immune response of SigA from day 28 post-challenge serum of one volunteer from S. flexneri 2a challenge studies. Our results demonstrate that SigA is immunogenic following infection with S. flexneri 2a. CONCLUSIONS: This work shows that SigA binds to epithelial HEp-2 cells as well as being able to induce fodrin degradation in vitro and in situ, further extending its documented role in the pathogenesis of Shigella infections.

  16. Intrinsic JNK-MAPK pathway involvement requires daf-16-mediated immune response during Shigella flexneri infection in C. elegans.

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    Marudhupandiyan, Shanmugam; Balamurugan, Krishnaswamy

    2017-06-01

    The c-Jun N-terminal kinase-mitogen-activated protein kinase (JNK-MAPK) pathway assists in modulating signals for growth, survival, and metabolism, thereby coordinating many cellular events during normal and stress conditions. To understand the role of the JNK-MAPK pathway during bacterial infection, an in vivo model organism Caenorhabditis elegans was used. In order to check the involvement of the JNK-MAPK pathway, the survival rate of C. elegans wild type (WT), and JNK-MAPK pathway mutant worms' upon exposure to selective Gram-positive and Gram-negative pathogenic bacteria, was studied. Among the pathogens, Shigella flexneri M9OT was found to efficiently colonize inside the WT and JNK-MAPK pathway mutant worms. qPCR studies had suggested that the above pathway-specific genes kgb-2 and jnk-1 were prominently responsible for the immune response elicited by the host during the M9OT infection. In addition, daf-16, which is a major transcription factor of the insulin/insulin growth factor-1 signaling (IIS) pathway, was also found to be involved during the host response. Crosstalk between IIS and JNK-MAPK pathways has probably been involved in the activation of the host immune system, which consequently leads to lifespan extension. Furthermore, it is also observed that daf-16 activation by JNK-MAPK pathway leads to antimicrobial response, by activating lys-7 expression. These findings suggest that JNK-MAPK is not the sole pathway that enhances the immunity of the host. Nonetheless, the IIS pathway bridges the JNK-MAPK pathway that influences in protecting the host in counter to the M9OT infection.

  17. Targeting of chromatin readers: a novel strategy used by the Shigella flexneri virulence effector OspF to reprogram transcription

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    Habiba Harouz

    2014-12-01

    Full Text Available Shigella flexneri, a gram-negative bacterium responsible of bacillary dysentery, uses multiple strategies to overcome host immune defense. We have decrypted how this bacterium manipulates host-cell chromatin binders to take control of immune gene expression. We found that OspF, an injected virulence factor previously identified as a repressor of immune gene expression, targets the chromatin reader HP1γ. Heterochromatin Protein 1 family members specifically recognize and bind histone H3 methylated at Lys 9. Although initially identified as chromatin-associated transcriptional silencers in heterochromatin, their location in euchromatin indicates an active role in gene expression. Notably, HP1γ phosphorylation at Serine 83 defines a subpopulation exclusively located to euchromatin, targeted to the site of transcriptional elongation. We showed that OspF directly interacts with HP1γ, and causes HP1 dephosphorylation, suggesting a model in which this virulence effector “uses” HP1 proteins as beacons to target and repress immune gene expression (Harouz, et al. EMBO J (2014. OspF alters HP1γ phosphorylation mainly by inactivating the Erk-activated kinase MSK1, spotlighting it as a new HP1 kinase. In vivo, infectious stresses trigger HP1γ phosphorylation in the colon, principally in the lamina propria and the intestinal crypts. Several lines of evidence suggest that HP1 proteins are modified as extensively as histones, and decrypting the impact of these HP1 post-translational modifications on their transcriptional activities in vivo will be the next challenges to be taken up.

  18. Detection of Salmonella Spp., Shigella (Flexneri and Sonnei) and Vibrio Cholerae O1 by Polymerase Chain Reaction (PCR) in Exported Shrimp from the Mexican Northeast Coast

    Energy Technology Data Exchange (ETDEWEB)

    Perez, L.; Nuñez, F.; Rubio, M.; Nicoli, M. [Universidad Nacional Autónoma de México, Facultad de Medicina Veterinaria y Zootecnia (Mexico)

    2005-01-15

    The objective of the present work was to use the PCR technique for the simultaneous detection of Salmonella spp and Vibrio cholerae O1 in frozen shrimp for export. The DNA segments located in the gene A [284 pairs of bases (pb)] from Salmonella spp. locus ial (217 and 320 pb) from Shigella flexneri and Shigella sonnei and the gene ctxA and ctxB (777 pb) from Vibrio cholerae O1 were amplified. The different primers that amplify these segments were assayed in a PCR reaction for the simultaneous detection of DNA from the microorganisms. It was not possible to amplify the gene of Shigella sonnei and Shigella flexneri under the assay’s conditions, whilst those of Salmonella spp. and Vibrio cholerae O1 were successfully amplified. The amplification conditions for the PCR were: 94° C, 58° C and 72° C during 30 cycles, allowing a reduction from 15 days test time with the official microbiological methods to 28 hours (24 for the pre-enrichment and four for the PCR). Samples of raw-frozen-headless shrimps were taken from production plants located in the State of Sinaloa, Mexico. A random sampling procedure was used, according to the guidelines described by the International Commission of Microbiological Specifications for Foods (ICMSF, 1999). Five packages per lot per production plant were obtained. From each individual package (5 pounds 80 OZ ≈ 2.27 kg) three samples were taken for the bacteriological assays to search for Salmonella spp. and Vibrio cholerae O1, respectively. The samples were also analyzed by PCR. Results showed that none of the samples were positive by PCR to any of the studied bacteria. Salmonella spp. and Vibrio cholerae O1 were not detected in these samples by the official methods. However, the latter were able to identify other Vibrio species and enterobacteria like Proteus and Acromobacter. These results confirmed PCR’s rapidity, sensitivity and specificity. (author)

  19. The normal chain length distribution of the O antigen is required for the interaction of Shigella flexneri 2a with polarized Caco-2 cells

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    Anilei Hoare

    2012-01-01

    Full Text Available Shigella flexneri causes bacillary dysentery in humans. Essential to the establishment of the disease is the invasion of the colonic epithelial cells. Here we investigated the role of the lipopolysaccharide (LPS O antigen in the ability of S. flexneri to adhere to and invade polarized Caco-2 cells. The S. flexneri 2a O antigen has two preferred chain lengths: a short O antigen (S-OAg regulated by the WzzB protein and a very long O antigen (VL-OAg regulated by Wzz pHS2. Mutants with defined deletions of the genes required for O-antigen assembly and polymerization were constructed and assayed for their abilities to adhere to and enter cultured epithelial cells. The results show that both VL- and S-OAg are required for invasion through the basolateral cell membrane. In contrast, the absence of O antigen does not impair adhesion. Purified LPS does not act as a competitor for the invasion of Caco-2 cells by the wild-type strain, suggesting that LPS is not directly involved in the internalization process by epithelial cells.

  20. Identification and Molecular Characterisation of a Novel Mu-Like Bacteriophage, SfMu, of Shigella flexneri.

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    Richa Jakhetia

    Full Text Available S. flexneri is the leading cause of bacillary dysentery in the developing countries. Several temperate phages originating from this host have been characterised. However, all S. flexneri phages known to date are lambdoid phages, which have the ability to confer the O-antigen modification of their host. In this study, we report the isolation and characterisation of a novel Mu-like phage from a serotype 4a strain of S. flexneri. The genome of phage SfMu is composed of 37,146 bp and is predicted to contain 55 open reading frames (orfs. Comparative genome analysis of phage SfMu with Mu and other Mu-like phages revealed that SfMu is closely related to phage Mu, sharing >90% identity with majority of its proteins. Moreover, investigation of phage SfMu receptor on the surface of the host cell revealed that the O-antigen of the host serves as the receptor for the adsorption of phage SfMu. This study also demonstrates pervasiveness of SfMu phage in S. flexneri, by identifying complete SfMu prophage strains of serotype X and Y, and remnants of SfMu in strains belonging to 4 other serotypes, thereby indicating that transposable phages in S. flexneri are not uncommon. The findings of this study contribute an advance in our current knowledge of S. flexneri phages and will also play a key role in understanding the evolution of S. flexneri.

  1. In vivo production of a novel glycoconjugate vaccine against Shigella flexneri 2a in recombinant Escherichia coli: identification of stimulating factors for in vivo glycosylation.

    Science.gov (United States)

    Kämpf, Michael M; Braun, Martin; Sirena, Dominique; Ihssen, Julian; Thöny-Meyer, Linda; Ren, Qun

    2015-01-23

    Glycoconjugated vaccines composed of polysaccharide antigens covalently linked to immunogenic carrier proteins have proved to belong to the most effective and safest vaccines for combating bacterial pathogens. The functional transfer of the N-glycosylation machinery from Campylobacter jejuni to the standard prokaryotic host Escherichia coli established a novel bioconjugation methodology termed bacterial glycoengineering. In this study, we report on the production of a new recombinant glycoconjugate vaccine against Shigella flexneri 2a representing the major serotype for global outbreaks of shigellosis. We demonstrate that S. flexneri 2a O-polysaccharides can be transferred to a detoxified variant of Pseudomonas aeruginosa carrier protein exotoxin A (EPA) by the C. jejuni oligosaccharyltransferase PglB, resulting in glycosylated EPA-2a. Moreover, we optimized the in vivo production of this novel vaccine by identification and quantitative analysis of critical process parameters for glycoprotein synthesis. It was found that sequential induction of oligosaccharyltransferase PglB and carrier protein EPA increased the specific productivity of EPA-2a by a factor of 1.6. Furthermore, by the addition of 10 g/L of the monosaccharide N-acetylglucosamine during induction, glycoconjugate vaccine yield was boosted up to 3.1-fold. The optimum concentration of Mg2+ ions for N-glycan transfer was determined to be 10 mM. Finally, optimized parameters were transferred to high cell density cultures with a 46-fold increase of overall yield of glycoconjugate compared to the one in initial shake flask production. The present study is the first attempt to identify stimulating parameters for improved productivity of S. flexneri 2a bioconjugates. Optimization of glycosylation efficiency will ultimately foster the transfer of lab-scale expression to a cost-effective in vivo production process for a glycoconjugate vaccine against S. flexneri 2a in E. coli. This study is an important step

  2. Identification of the bile salt binding site on IpaD from Shigella flexneri and the influence of ligand binding on IpaD structure.

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    Barta, Michael L; Guragain, Manita; Adam, Philip; Dickenson, Nicholas E; Patil, Mrinalini; Geisbrecht, Brian V; Picking, Wendy L; Picking, William D

    2012-03-01

    Type III secretion (TTS) is an essential virulence factor for Shigella flexneri, the causative agent of shigellosis. The Shigella TTS apparatus (TTSA) is an elegant nanomachine that is composed of a basal body, an external needle to deliver effectors into human cells, and a needle tip complex that controls secretion activation. IpaD is at the tip of the nascent TTSA needle where it controls the first step of TTS activation. The bile salt deoxycholate (DOC) binds to IpaD to induce recruitment of the translocator protein IpaB into the maturing tip complex. We recently used spectroscopic analyses to show that IpaD undergoes a structural rearrangement that accompanies binding to DOC. Here, we report a crystal structure of IpaD with DOC bound and test the importance of the residues that make up the DOC binding pocket on IpaD function. IpaD binds DOC at the interface between helices α3 and α7, with concomitant movement in the orientation of helix α7 relative to its position in unbound IpaD. When the IpaD residues involved in DOC binding are mutated, some are found to lead to altered invasion and secretion phenotypes. These findings suggest that adoption of a DOC bound structural state for IpaD primes the Shigella TTSA for contact with host cells. The data presented here and in the studies leading up to this work provide the foundation for developing a model of the first step in Shigella TTS activation.

  3. MxiA, MxiC and IpaD Regulate Substrate Selection and Secretion Mode in the T3SS of Shigella flexneri.

    Science.gov (United States)

    Shen, Da-Kang; Blocker, Ariel J

    2016-01-01

    Type III secretion systems (T3SSs) are central virulence devices for many Gram-negative bacterial pathogens of humans, animals & plants. Upon physical contact with eukaryotic host cells, they translocate virulence-mediating proteins, known as effectors, into them during infection. T3SSs are gated from the outside by host-cell contact and from the inside via two cytoplasmic negative regulators, MxiC and IpaD in Shigella flexneri, which together control the effector secretion hierarchy. Their absence leads to premature and increased secretion of effectors. Here, we investigated where and how these regulators act. We demonstrate that the T3SS inner membrane export apparatus protein MxiA plays a role in substrate selection. Indeed, using a genetic screen, we identified two amino acids located on the surface of MxiA's cytoplasmic region (MxiAC) which, when mutated, upregulate late effector expression and, in the case of MxiAI674V, also secretion. The cytoplasmic region of MxiA, but not MxiAN373D and MxiAI674V, interacts directly with the C-terminus of MxiC in a two-hybrid assay. Efficient T3S requires a cytoplasmic ATPase and the proton motive force (PMF), which is composed of the ΔΨ and the ΔpH. MxiA family proteins and their regulators are implicated in utilization of the PMF for protein export. However, our MxiA point mutants show similar PMF utilisation to wild-type, requiring primarily the ΔΨ. On the other hand, lack of MxiC or IpaD, renders the faster T3S seen increasingly dependent on the ΔpH. Therefore, MxiA, MxiC and IpaD act together to regulate substrate selection and secretion mode in the T3SS of Shigella flexneri.

  4. Expression, purification, crystallization and preliminary crystallographic analysis of MxiH, a subunit of the Shigella flexneri type III secretion system needle

    International Nuclear Information System (INIS)

    Deane, Janet E.; Cordes, Frank S.; Roversi, Pietro; Johnson, Steven; Kenjale, Roma; Picking, William D.; Picking, Wendy L.; Lea, Susan M.; Blocker, Ariel

    2006-01-01

    A monodisperse truncation mutant of MxiH, the subunit of the S. flexneri type III secretion system needle, has been crystallized. SeMet derivatives and a uranyl derivative have undergone preliminary crystallographic analysis. A monodisperse truncation mutant of MxiH, the subunit of the needle from the Shigella flexneri type III secretion system (TTSS), has been overexpressed and purified. Crystals were grown of native and selenomethionine-labelled MxiH CΔ5 and diffraction data were collected to 1.9 Å resolution. The crystals belong to space group C2, with unit-cell parameters a = 183.4, b = 28.1, c = 27.8 Å, β = 96.5°. An anomalous difference Patterson map calculated with the data from the SeMet-labelled crystals revealed a single peak on the Harker section v = 0. Inspection of a uranyl derivative also revealed one peak in the isomorphous difference Patterson map on the Harker section v = 0. Analysis of the self-rotation function indicates the presence of a twofold non-crystallographic symmetry axis approximately along a. The calculated Matthews coefficient is 1.9 Å 3 Da −1 for two molecules per asymmetric unit, corresponding to a solvent content of 33%

  5. Expression, purification, crystallization and preliminary crystallographic analysis of MxiH, a subunit of the Shigella flexneri type III secretion system needle

    Energy Technology Data Exchange (ETDEWEB)

    Deane, Janet E.; Cordes, Frank S.; Roversi, Pietro [Laboratory of Molecular Biophysics, Department of Biochemistry, University of Oxford (United Kingdom); Johnson, Steven [Laboratory of Molecular Biophysics, Department of Biochemistry, University of Oxford (United Kingdom); Sir William Dunn School of Pathology, University of Oxford (United Kingdom); Kenjale, Roma; Picking, William D.; Picking, Wendy L. [Department of Molecular Biosciences, University of Kansas (United States); Lea, Susan M., E-mail: susan.lea@biop.ox.ac.uk [Laboratory of Molecular Biophysics, Department of Biochemistry, University of Oxford (United Kingdom); Sir William Dunn School of Pathology, University of Oxford (United Kingdom); Blocker, Ariel [Sir William Dunn School of Pathology, University of Oxford (United Kingdom); Laboratory of Molecular Biophysics, Department of Biochemistry, University of Oxford (United Kingdom)

    2006-03-01

    A monodisperse truncation mutant of MxiH, the subunit of the S. flexneri type III secretion system needle, has been crystallized. SeMet derivatives and a uranyl derivative have undergone preliminary crystallographic analysis. A monodisperse truncation mutant of MxiH, the subunit of the needle from the Shigella flexneri type III secretion system (TTSS), has been overexpressed and purified. Crystals were grown of native and selenomethionine-labelled MxiH{sub CΔ5} and diffraction data were collected to 1.9 Å resolution. The crystals belong to space group C2, with unit-cell parameters a = 183.4, b = 28.1, c = 27.8 Å, β = 96.5°. An anomalous difference Patterson map calculated with the data from the SeMet-labelled crystals revealed a single peak on the Harker section v = 0. Inspection of a uranyl derivative also revealed one peak in the isomorphous difference Patterson map on the Harker section v = 0. Analysis of the self-rotation function indicates the presence of a twofold non-crystallographic symmetry axis approximately along a. The calculated Matthews coefficient is 1.9 Å{sup 3} Da{sup −1} for two molecules per asymmetric unit, corresponding to a solvent content of 33%.

  6. Conformational changes in IpaD from Shigella flexneri upon binding bile salts provide insight into the second step of type III secretion.

    Science.gov (United States)

    Dickenson, Nicholas E; Zhang, Lingling; Epler, Chelsea R; Adam, Philip R; Picking, Wendy L; Picking, William D

    2011-01-18

    Shigella flexneri uses its type III secretion apparatus (TTSA) to inject host-altering proteins into targeted eukaryotic cells. The TTSA is composed of a basal body and an exposed needle with invasion plasmid antigen D (IpaD) forming a tip complex that controls secretion. The bile salt deoxycholate (DOC) stimulates recruitment of the translocator protein IpaB into the maturing TTSA needle tip complex. This process appears to be triggered by a direct interaction between DOC and IpaD. Fluorescence spectroscopy and NMR spectroscopy are used here to confirm the DOC-IpaD interaction and to reveal that IpaD conformational changes upon DOC binding trigger the appearance of IpaB at the needle tip. Förster resonance energy transfer between specific sites on IpaD was used here to identify changes in distances between IpaD domains as a result of DOC binding. To further explore the effects of DOC binding on IpaD structure, NMR chemical shift mapping was employed. The environments of residues within the proposed DOC binding site and additional residues within the "distal" globular domain were perturbed upon DOC binding, further indicating that conformational changes occur within IpaD upon DOC binding. These events are proposed to be responsible for the recruitment of IpaB at the TTSA needle tip. Mutation analyses combined with additional spectroscopic analyses confirm that conformational changes in IpaD induced by DOC binding contribute to the recruitment of IpaB to the S. flexneri TTSA needle tip. These findings lay the foundation for determining how environmental factors promote TTSA needle tip maturation prior to host cell contact.

  7. Two studies evaluating the safety and immunogenicity of a live, attenuated Shigella flexneri 2a vaccine (SC602) and excretion of vaccine organisms in North American volunteers.

    Science.gov (United States)

    Katz, David E; Coster, Trinka S; Wolf, Marcia K; Trespalacios, Fernando C; Cohen, Dani; Robins, Guy; Hartman, Antoinette B; Venkatesan, Malabi M; Taylor, David N; Hale, Thomas L

    2004-02-01

    We report the first community-based evaluation of Shigella flexneri 2a strain SC602, a live, oral vaccine strain attenuated by deletion of the icsA (virG) plasmid virulence gene, given at 10(4) CFU. The primary objectives of this trial were to determine the safety and immunogenicity of the vaccine and to determine the duration of colonization. Four of 34 volunteers experienced transient fevers, and three reported diarrhea during the first 3 days of the study. Half of the volunteers mounted a positive serum immunoglobulin A (IgA) response to S. flexneri lipopolysaccharide. All but one of the volunteers excreted the vaccine in their stools for 1 to 33 days, and this excretion was often intermittent. Data from the community-based study were supplemented with an inpatient trial in which three volunteers received 10(3) and nine received 10(4) CFU. All volunteers who received 10(3) CFU excreted SC602 and had an IgA antibody-secreting cell response. Two of these had a serum IgA response. Six of the nine volunteers who received 10(4) CFU excreted SC602. One vaccinee had a transient fever and two met the definition of diarrhea. Six volunteers that received 10(4) CFU had an antibody-secreting cell response, and four had a serum IgA response. SC602 has now been tested at 10(4) CFU in a total of 58 volunteers. The cumulative results of these clinical trials, reported here and previously (Coster et al., Infect. Immun. 67:3437-3443, 1999), have demonstrated that SC602 is a substantially attenuated candidate vaccine that can evoke protection against the most severe symptoms of shigellosis in a stringent human challenge model of disease.

  8. Attenuated Salmonella enterica serovar Typhi and Shigella flexneri 2a strains mucosally deliver DNA vaccines encoding measles virus hemagglutinin, inducing specific immune responses and protection in cotton rats.

    Science.gov (United States)

    Pasetti, Marcela F; Barry, Eileen M; Losonsky, Genevieve; Singh, Mahender; Medina-Moreno, Sandra M; Polo, John M; Ulmer, Jeffrey; Robinson, Harriet; Sztein, Marcelo B; Levine, Myron M

    2003-05-01

    Measles remains a leading cause of child mortality in developing countries. Residual maternal measles antibodies and immunologic immaturity dampen immunogenicity of the current vaccine in young infants. Because cotton rat respiratory tract is susceptible to measles virus (MV) replication after intranasal (i.n.) challenge, this model can be used to assess the efficacy of MV vaccines. Pursuing a new measles vaccine strategy that might be effective in young infants, we used attenuated Salmonella enterica serovar Typhi CVD 908-htrA and Shigella flexneri 2a CVD 1208 vaccines to deliver mucosally to cotton rats eukaryotic expression plasmid pGA3-mH and Sindbis virus-based DNA replicon pMSIN-H encoding MV hemagglutinin (H). The initial i.n. dose-response with bacterial vectors alone identified a well-tolerated dosage (1 x 10(9) to 7 x 10(9) CFU) and a volume (20 micro l) that elicited strong antivector immune responses. Animals immunized i.n. on days 0, 28, and 76 with bacterial vectors carrying DNA plasmids encoding MV H or immunized parenterally with these naked DNA vaccine plasmids developed MV plaque reduction neutralizing antibodies and proliferative responses against MV antigens. In a subsequent experiment of identical design, cotton rats were challenged with wild-type MV 1 month after the third dose of vaccine or placebo. MV titers were significantly reduced in lung tissue of animals immunized with MV DNA vaccines delivered either via bacterial live vectors or parenterally. Since attenuated serovar Typhi and S. flexneri can deliver measles DNA vaccines mucosally in cotton rats, inducing measles immune responses (including neutralizing antibodies) and protection, boosting strategies can now be evaluated in animals primed with MV DNA vaccines.

  9. Conformational Changes in IpaD from Shigella flexneri Upon Binding Bile Salts Provide Insight into the Second Step of Type III Secretion†

    Science.gov (United States)

    Dickenson, Nicholas E.; Zhang, Lingling; Epler, Chelsea R.; Adam, Philip R.; Picking, Wendy L.; Picking, William D.

    2011-01-01

    Shigella flexneri uses its type III secretion apparatus (TTSA) to inject host-altering proteins into targeted eukaryotic cells. The TTSA is composed of a basal body and an exposed needle with invasion plasmid antigen D (IpaD) forming a tip complex that controls secretion. The bile salt deoxycholate (DOC) stimulates recruitment of the translocator protein IpaB into the maturing TTSA needle tip complex. This process appears to be triggered by a direct interaction between DOC and IpaD. Fluorescence spectroscopy and NMR spectroscopy are used here to confirm the DOC-IpaD interaction and to reveal that IpaD conformational changes upon DOC binding trigger the appearance of IpaB at the needle tip. Förster resonance energy transfer between specific sites on IpaD was used here to identify changes in distances between IpaD domains as a result of DOC binding. To further explore the effects of DOC binding on IpaD structure, NMR chemical shift mapping was employed. The environments of residues within the proposed DOC binding site and additional residues within the “distal” globular domain were perturbed upon DOC binding, further indicating that conformational changes occur within IpaD upon DOC binding. These events are proposed to be responsible for the recruitment of IpaB at the TTSA needle tip. Mutation analyses combined with additional spectroscopic analyses confirms that conformational changes in IpaD induced by DOC binding contribute to the recruitment of IpaB to the S. flexneri TTSA needle tip. These findings lay the foundation for determining how environmental factors promote TTSA needle tip maturation prior to host cell contact. PMID:21126091

  10. Expression, limited proteolysis and preliminary crystallographic analysis of IpaD, a component of the Shigella flexneri type III secretion system

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Steven [Laboratory of Molecular Biophysics, Department of Biochemistry, University of Oxford (United Kingdom); Sir William Dunn School of Pathology, University of Oxford (United Kingdom); Roversi, Pietro [Laboratory of Molecular Biophysics, Department of Biochemistry, University of Oxford (United Kingdom); Espina, Marianela [Department of Molecular Biosciences, University of Kansas (United States); Deane, Janet E. [Laboratory of Molecular Biophysics, Department of Biochemistry, University of Oxford (United Kingdom); Birket, Susan; Picking, William D. [Department of Molecular Biosciences, University of Kansas (United States); Blocker, Ariel [Sir William Dunn School of Pathology, University of Oxford (United Kingdom); Picking, Wendy L. [Department of Molecular Biosciences, University of Kansas (United States); Lea, Susan M., E-mail: susan.lea@path.ox.ac.uk [Laboratory of Molecular Biophysics, Department of Biochemistry, University of Oxford (United Kingdom); Sir William Dunn School of Pathology, University of Oxford (United Kingdom)

    2006-09-01

    IpaD, the putative needle-tip protein of the S. flexneri type III secretion system, has been crystallized in a variety of crystal forms using in-drop proteolysis. Native and selenomethionine-labelled data collection and preliminary analyses are reported. IpaD, the putative needle-tip protein of the Shigella flexneri type III secretion system, has been overexpressed and purified. Crystals were grown of the native protein in space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 55.9, b = 100.7, c = 112.0 Å, and data were collected to 2.9 Å resolution. Analysis of the native Patterson map revealed a peak at 50% of the origin on the Harker section v = 0.5, suggesting twofold non-crystallographic symmetry parallel to the b crystallographic axis. As attempts to derivatize or grow selenomethionine-labelled protein crystals failed, in-drop proteolysis was used to produce new crystal forms. A trace amount of subtilisin Carlsberg was added to IpaD before sparse-matrix screening, resulting in the production of several new crystal forms. This approach produced SeMet-labelled crystals and diffraction data were collected to 3.2 Å resolution. The SeMet crystals belong to space group C2, with unit-cell parameters a = 139.4, b = 45.0, c = 99.5 Å, β = 107.9°. An anomalous difference Patterson map revealed peaks on the Harker section v = 0, while the self-rotation function indicates the presence of a twofold noncrystallographic symmetry axis, which is consistent with two molecules per asymmetric unit.

  11. Expression, limited proteolysis and preliminary crystallographic analysis of IpaD, a component of the Shigella flexneri type III secretion system

    International Nuclear Information System (INIS)

    Johnson, Steven; Roversi, Pietro; Espina, Marianela; Deane, Janet E.; Birket, Susan; Picking, William D.; Blocker, Ariel; Picking, Wendy L.; Lea, Susan M.

    2006-01-01

    IpaD, the putative needle-tip protein of the S. flexneri type III secretion system, has been crystallized in a variety of crystal forms using in-drop proteolysis. Native and selenomethionine-labelled data collection and preliminary analyses are reported. IpaD, the putative needle-tip protein of the Shigella flexneri type III secretion system, has been overexpressed and purified. Crystals were grown of the native protein in space group P2 1 2 1 2 1 , with unit-cell parameters a = 55.9, b = 100.7, c = 112.0 Å, and data were collected to 2.9 Å resolution. Analysis of the native Patterson map revealed a peak at 50% of the origin on the Harker section v = 0.5, suggesting twofold non-crystallographic symmetry parallel to the b crystallographic axis. As attempts to derivatize or grow selenomethionine-labelled protein crystals failed, in-drop proteolysis was used to produce new crystal forms. A trace amount of subtilisin Carlsberg was added to IpaD before sparse-matrix screening, resulting in the production of several new crystal forms. This approach produced SeMet-labelled crystals and diffraction data were collected to 3.2 Å resolution. The SeMet crystals belong to space group C2, with unit-cell parameters a = 139.4, b = 45.0, c = 99.5 Å, β = 107.9°. An anomalous difference Patterson map revealed peaks on the Harker section v = 0, while the self-rotation function indicates the presence of a twofold noncrystallographic symmetry axis, which is consistent with two molecules per asymmetric unit

  12. Shigella

    Science.gov (United States)

    Marteyn, Benoit; Gazi, Anastasia; Sansonetti, Philippe

    2012-01-01

    Much is known about the molecular effectors of pathogenicity of gram-negative enteric pathogens, among which Shigella can be considered a model. This is due to its capacity to recapitulate the multiple steps required for a pathogenic microbe to survive close to its mucosal target, colonize and then invade its epithelial surface, cause its inflammatory destruction and simultaneously regulate the extent of the elicited innate response to likely survive the encounter and achieve successful subsequent transmission. These various steps of the infectious process represent an array of successive environmental conditions to which the bacteria need to successfully adapt. These conditions represent the selective pressure that triggered the “arms race” in which Shigella acquired the genetic and molecular effectors of its pathogenic armory, including the regulatory hierarchies that regulate the expression and function of these effectors. They also represent cues through which Shigella achieves the temporo-spatial expression and regulation of its virulence effectors. The role of such environmental cues has recently become obvious in the case of the major virulence effector of Shigella, the type three secretion system (T3SS) and its dedicated secreted virulence effectors. It needs to be better defined for other major virulence components such as the LPS and peptidoglycan which are used as examples here, in addition to the T3SS as models of regulation as it relates to the assembly and functional regulation of complex macromolecular systems of the bacterial surface. This review also stresses the need to better define what the true and relevant environmental conditions can be at the various steps of the progression of infection. The “identity” of the pathogen differs depending whether it is cultivated under in vitro or in vivo conditions. Moreover, this “identity” may quickly change during its progression into the infected tissue. Novel concepts and relevant tools are

  13. Shigella outer membrane protein PSSP-1 is broadly protective against Shigella infection.

    Science.gov (United States)

    Kim, Jae-Ouk; Rho, Semi; Kim, Su Hee; Kim, Heejoo; Song, Hyo Jin; Kim, Eun Jin; Kim, Ryang Yeo; Kim, Eun Hye; Sinha, Anuradha; Dey, Ayan; Yang, Jae Seung; Song, Man Ki; Nandy, Ranjan Kumar; Czerkinsky, Cecil; Kim, Dong Wook

    2015-04-01

    In developing countries, Shigella is a primary cause of diarrhea in infants and young children. Although antibiotic therapy is an effective treatment for shigellosis, therapeutic options are narrowing due to the emergence of antibiotic resistance. Thus, preventive vaccination could become the most efficacious approach for controlling shigellosis. We have identified several conserved protein antigens that are shared by multiple Shigella serotypes and species. Among these, one antigen induced cross-protection against experimental shigellosis, and we have named it pan-Shigella surface protein 1 (PSSP-1). PSSP-1-induced protection requires a mucosal administration route and coadministration of an adjuvant. When PSSP-1 was administered intranasally, it induced cross-protection against Shigella flexneri serotypes 2a, 5a, and 6, Shigella boydii, Shigella sonnei, and Shigella dysenteriae serotype 1. Intradermally administered PSSP-1 induced strong serum antibody responses but failed to induce protection in the mouse lung pneumonia model. In contrast, intranasal administration elicited efficient local and systemic antibody responses and production of interleukin 17A and gamma interferon. Interestingly, blood samples from patients with recent-onset shigellosis showed variable but significant mucosal antibody responses to other conserved Shigella protein antigens but not to PSSP-1. We suggest that PSSP-1 is a promising antigen for a broadly protective vaccine against Shigella. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  14. Clostridium difficile Recombinant Toxin A Repeating Units as a Carrier Protein for Conjugate Vaccines: Studies of Pneumococcal Type 14, Escherichia coli K1, and Shigella flexneri Type 2a Polysaccharides in Mice

    Science.gov (United States)

    Pavliakova, Danka; Moncrief, J. Scott; Lyerly, David M.; Schiffman, Gerald; Bryla, Dolores A.; Robbins, John B.; Schneerson, Rachel

    2000-01-01

    Unlike the native protein, a nontoxic peptide (repeating unit of the native toxin designated rARU) from Clostridium difficile toxin A (CDTA) afforded an antigen that could be bound covalently to the surface polysaccharides of pneumococcus type 14, Shigella flexneri type 2a, and Escherichia coli K1. The yields of these polysaccharide-protein conjugates were significantly increased by prior treatment of rARU with succinic anhydride. Conjugates, prepared with rARU or succinylated (rARUsucc), were administered to mice by a clinically relevant dosage and immunization scheme. All conjugates elicited high levels of serum immunoglobulin G both to the polysaccharides and to CDTA. Conjugate-induced anti-CDTA had neutralizing activity in vitro and protected mice challenged with CDTA, similar to the rARU alone. Conjugates prepared with succinylated rARU, therefore, have potential for serving both as effective carrier proteins for polysaccharides and for preventing enteric disease caused by C. difficile. PMID:10722615

  15. 密度感应系统对弗氏志贺菌生长竞争能力的影响%The effect of quorum sensing system for growth competitiveness on Shigella flexneri

    Institute of Scientific and Technical Information of China (English)

    徐苹; 杨晶; 陆丽兰; 冯尔玲; 王恒樑; 卢瑛; 朱力

    2015-01-01

    Quorum sensing (QS) regulates the onset of bacterial social responses related to cell density. Compari-son between the gene sequences of all components of QS system ofEscherichia coli andShigella strains, shows that the QS system is generally lost or mutated inShigella. Since AI-2 is produced and processed by thelsr operon, we analyzed the potential function of thelsroperon. We first detected AI-2 inShigella flexneri2a strain 301 through the reporter bacteriaVibrio harveyiBB170, indicating thatS. flexnerican produce AI-2. Then, thelsroperon ofE. coli MG1655was cloned intoS. flexneri using the Golden Gate method. Colony counting experiments showed that the QS system recovery strain had growth advantage over the wild-type strain when they were mixed and cultured. The pre-liminary comparative proteomics analysis showed that thelsroperon could be expressed and the abundance of stress response proteins also changed when the QS system was introduced into S. flexneri.%密度感应系统调节细菌应答反应的发生,这些应答反应与细胞密度有关.通过对比大肠杆菌(Escherichia coli)和志贺氏菌(Shigellaspp.)的序列发现,志贺菌属密度感应系统操纵子普遍存在丢失或突变.为研究其密度感应系统的功能,文章利用哈氏弧菌(Vibrio harveyi)BB170作为指示菌,检测弗氏志贺菌(Shigella flexneri)密度感应系统信号分子AI-2,证明其可以分泌有活性的AI-2;其次,采用Golden Gate克隆法将大肠杆菌MG1655的密度感应系统基因克隆至弗氏志贺菌301中,获得密度感应系统回复株301.通过菌落计数表明,在混合培养条件下,密度感应系统基因回复株301比野生株301存在生长优势;通过双向电泳初步比较分析表明,密度感应系统基因可以在志贺菌中表达,并鉴定到了其他一些与应激反应相关的差异表达蛋白, 如Hsp60、GroEL、SodB.

  16. Serogroup prevalence of Shigellae in Bombay.

    Directory of Open Access Journals (Sweden)

    Sonawala M

    1995-10-01

    Full Text Available Prevalence of Shigellae serotypes in Bombay was studied from June 1988 to May 1991. A total of 2758 faecal specimens were collected from paediatric patients (< 12 yrs with acute gastroenteritis. A total of 90 Shigella were isolated giving the isolation rate of 3.2%. Shigella flexneri was the predominant serogroup (73.3% followed by Shigella dysenteriae (16.6%. All the isolates were sensitive to nalidixic acid. Eighty percent of the Shigellae were multidrug resistant. Present data were compared with the study carried out during the period of 1983-87 from the same institute. A change in the serogroup prevalence was noted wherein Shigella flexneri dominated over Shigella dysenteriae since 1985. Increase in resistance to ampicillin and cotrimoxazole was seen in Shigella flexneri strains as compared to previous years.

  17. A multi-pathogen selective enrichment broth for simultaneous growth of Salmonella enteria, Escherichia coli O157:H7 and Shigella flexneri

    Science.gov (United States)

    Salmonella, Shigella, and Escherichia coli O157:H7 contaminate similar types of food and all three can cause foodborne disease. Traditional microbiological enrichment broths to detect these pathogens are different in terms of their composition, which limits the application of multi-pathogen detectio...

  18. Outer membrane protein A (OmpA of Shigella flexneri 2a induces TLR2-mediated activation of B cells: involvement of protein tyrosine kinase, ERK and NF-κB.

    Directory of Open Access Journals (Sweden)

    Rajsekhar Bhowmick

    Full Text Available B cells are critically important in combating bacterial infections and their differentiation into plasma cells and memory cells aids bacterial clearance and long-lasting immunity conferred by essentially all vaccines. Outer membrane protein A (OmpA of Shigella flexneri 2a has been demonstrated to induce the production of IgG and IgA in vivo following immunization of mice through intranasal route, but the direct involvement of B cells in OmpA-mediated immune regulation was not determined. Consequently, we investigated whether OmpA can modulate B cell functions and identified the molecular events involved in OmpA-induced B cell immune response in vitro. We show that OmpA of S. flexneri 2a activates B cells to produce protective cytokines, IL-6 and IL-10 as well as facilitates their differentiation into antibody secreting cells (ASCs. The immunostimulatory properties of OmpA are attributed to the increased surface expression of MHCII and CD86 on B cells. We also report here that B cell activation by OmpA is mediated strictly through recognition by TLR2, resulting in initiation of cascades of signal transduction events, involving increased phosphorylation of protein tyrosine kinases (PTKs, ERK and IκBα, leading to nuclear translocation of NF-κB. Importantly, a TLR2 antibody diminishes OmpA-induced upregulation of MHCII and CD86 on B cell surface as well as significantly inhibits B cell differentiation and cytokine secretion. Furthermore, we illustrate that B cell differentiation into ASCs and induction of cytokine secretion by OmpA are dependent on PTKs activity. Moreover, we identify that OmpA-induced B cell differentiation is entirely dependent on ERK pathway, whereas both NF-κB and ERK are essential for cytokine secretion by B cells. Overall, our data demonstrate that OmpA of S. flexneri 2a amplifies TLR signaling in B cells and triggers B cell immune response, which is critical for the development of an effective adaptive immunity to an

  19. Serum immune response to Shigella protein antigens in rhesus monkeys and humans infected with Shigella spp.

    OpenAIRE

    Oaks, E V; Hale, T L; Formal, S B

    1986-01-01

    The serum antibody response to proteins encoded by the virulence-associated plasmid of Shigella flexneri was determined in monkeys challenged with virulent S. flexneri serotype 2a. With water-extractable antigen in an enzyme-linked immunosorbent assay, a significant increase in antibody titer against proteins from a plasmid-carrying, virulent strain of S. flexneri serotype 5 could be demonstrated in convalescent sera. There were minimal antibody titers against proteins from an avirulent (plas...

  20. Shigella isolates from the global enteric multicenter study inform vaccine development.

    Science.gov (United States)

    Livio, Sofie; Strockbine, Nancy A; Panchalingam, Sandra; Tennant, Sharon M; Barry, Eileen M; Marohn, Mark E; Antonio, Martin; Hossain, Anowar; Mandomando, Inacio; Ochieng, John B; Oundo, Joseph O; Qureshi, Shahida; Ramamurthy, Thandavarayan; Tamboura, Boubou; Adegbola, Richard A; Hossain, Mohammed Jahangir; Saha, Debasish; Sen, Sunil; Faruque, Abu Syed Golam; Alonso, Pedro L; Breiman, Robert F; Zaidi, Anita K M; Sur, Dipika; Sow, Samba O; Berkeley, Lynette Y; O'Reilly, Ciara E; Mintz, Eric D; Biswas, Kousick; Cohen, Dani; Farag, Tamer H; Nasrin, Dilruba; Wu, Yukun; Blackwelder, William C; Kotloff, Karen L; Nataro, James P; Levine, Myron M

    2014-10-01

    Shigella, a major diarrheal disease pathogen worldwide, is the target of vaccine development. The Global Enteric Multicenter Study (GEMS) investigated burden and etiology of moderate-to-severe diarrheal disease in children aged Shigella was 1 of the 4 most common pathogens across sites and age strata. GEMS Shigella serotypes are reviewed to guide vaccine development. Subjects' stool specimens/rectal swabs were transported to site laboratories in transport media and plated onto xylose lysine desoxycholate and MacConkey agar. Suspect Shigella colonies were identified by biochemical tests and agglutination with antisera. Shigella isolates were shipped to the GEMS Reference Laboratory (Baltimore, MD) for confirmation and serotyping of S. flexneri; one-third of isolates were sent to the Centers for Disease Control and Prevention for quality control. Shigella dysenteriae and S. boydii accounted for 5.0% and 5.4%, respectively, of 1130 Shigella case isolates; S. flexneri comprised 65.9% and S. sonnei 23.7%. Five serotypes/subserotypes comprised 89.4% of S. flexneri, including S. flexneri 2a, S. flexneri 6, S. flexneri 3a, S. flexneri 2b, and S. flexneri 1b. A broad-spectrum Shigella vaccine must protect against S. sonnei and 15 S. flexneri serotypes/subserotypes. A quadrivalent vaccine with O antigens from S. sonnei, S. flexneri 2a, S. flexneri 3a, and S. flexneri 6 can provide broad direct coverage against these most common serotypes and indirect coverage against all but 1 (rare) remaining subserotype through shared S. flexneri group antigens. © The Author 2014. Published by Oxford University Press on behalf of the Infectious Diseases Society of America.

  1. Antibodies against Shigella flexneri adhesion molecule outer ...

    African Journals Online (AJOL)

    Tropical Journal of Pharmaceutical Research February 2017; 16 (2): 255-261 ... Milliana et al. Trop J Pharm Res, February 2017; 16(2): 256 .... Significance level was set at p ˂. 0.05. ..... labile colonization factor antigen (CFA/II) produced by.

  2. Antimicrobial-resistant Shigella infections from Iran

    DEFF Research Database (Denmark)

    Tajbakhsh, Mercedeh; García Migura, Lourdes; Rahbar, Mohammad

    2012-01-01

    Objectives: In this study, we wanted to assess the level of antimicrobial resistance, the presence of genes encoding resistance to cephalosporins and plasmid-mediated quinolone resistance (PMQR), and genetic relatedness among Shigella isolates obtained from Iranian patients. ; Methods: A total...... of 44 Shigella isolates were collected from Iranian patients admitted to Milad Hospital, Tehran, Iran, during 2008–10. Of these, 37 were serotyped and characterized by MIC determination. A subset of eight suspected extended-spectrum β-lactamase (ESBL) producers (six Shigella sonnei phase II and two...... Shigella flexneri type 1b) were examined for the presence of genes encoding cephalosporin resistance. The presence of PMQR was assessed in one S. flexneri isolate exhibiting low-level resistance to ciprofloxacin and susceptibility to nalidixic acid. PFGE was performed on 25 S. sonnei phase II isolates...

  3. Shigella Infections

    Science.gov (United States)

    ... Staying Safe Videos for Educators Search English Español Shigella Infections KidsHealth / For Parents / Shigella Infections What's in ... Doctor Print en español Infecciones por Shigella About Shigella Shigella are bacteria that can infect the digestive ...

  4. Multiplex Polymerase Chain Reaction for Identification of Shigellae and Four Shigella Species Using Novel Genetic Markers Screened by Comparative Genomics.

    Science.gov (United States)

    Kim, Hyun-Joong; Ryu, Ji-Oh; Song, Ji-Yeon; Kim, Hae-Yeong

    2017-07-01

    In the detection of Shigella species using molecular biological methods, previously known genetic markers for Shigella species were not sufficient to discriminate between Shigella species and diarrheagenic Escherichia coli. The purposes of this study were to screen for genetic markers of the Shigella genus and four Shigella species through comparative genomics and develop a multiplex polymerase chain reaction (PCR) for the detection of shigellae and Shigella species. A total of seven genomic DNA sequences from Shigella species were subjected to comparative genomics for the screening of genetic markers of shigellae and each Shigella species. The primer sets were designed from the screened genetic markers and evaluated using PCR with genomic DNAs from Shigella and other bacterial strains in Enterobacteriaceae. A novel Shigella quintuplex PCR, designed for the detection of Shigella genus, S. dysenteriae, S. boydii, S. flexneri, and S. sonnei, was developed from the evaluated primer sets, and its performance was demonstrated with specifically amplified results from each Shigella species. This Shigella multiplex PCR is the first to be reported with novel genetic markers developed through comparative genomics and may be a useful tool for the accurate detection of the Shigella genus and species from closely related bacteria in clinical microbiology and food safety.

  5. Polar localization of PhoN2, a periplasmic virulence-associated factor of Shigella flexneri, is required for proper IcsA exposition at the old bacterial pole.

    Directory of Open Access Journals (Sweden)

    Daniela Scribano

    Full Text Available Proper protein localization is critical for bacterial virulence. PhoN2 is a virulence-associated ATP-diphosphohydrolase (apyrase involved in IcsA-mediated actin-based motility of S. flexneri. Herein, by analyzing a ΔphoN2 mutant of the S. flexneri strain M90T and by generating phoN2::HA fusions, we show that PhoN2, is a periplasmic protein that strictly localizes at the bacterial poles, with a strong preference for the old pole, the pole where IcsA is exposed, and that it is required for proper IcsA exposition. PhoN2-HA was found to be polarly localized both when phoN2::HA was ectopically expressed in a Escherichia coli K-12 strain and in a S. flexneri virulence plasmid-cured mutant, indicating a conserved mechanism of PhoN2 polar delivery across species and that neither IcsA nor the expression of other virulence-plasmid encoded genes are involved in this process. To assess whether PhoN2 and IcsA may interact, two-hybrid and cross-linking experiments were performed. While no evidence was found of a PhoN2-IcsA interaction, unexpectedly the outer membrane protein A (OmpA was shown to bind PhoN2-HA through its periplasmic-exposed C-terminal domain. Therefore, to identify PhoN2 domains involved in its periplasmic polar delivery as well as in the interaction with OmpA, a deletion and a set of specific amino acid substitutions were generated. Analysis of these mutants indicated that neither the (183PAPAP(187 motif of OmpA, nor the N-terminal polyproline (43PPPP(46 motif and the Y155 residue of PhoN2 are involved in this interaction while P45, P46 and Y155 residues were found to be critical for the correct folding and stability of the protein. The relative rapid degradation of these amino acid-substituted recombinant proteins was found to be due to unknown S. flexneri-specific protease(s. A model depicting how the PhoN2-OmpA interaction may contribute to proper polar IcsA exposition in S. flexneri is presented.

  6. Polar localization of PhoN2, a periplasmic virulence-associated factor of Shigella flexneri, is required for proper IcsA exposition at the old bacterial pole.

    Science.gov (United States)

    Scribano, Daniela; Petrucca, Andrea; Pompili, Monica; Ambrosi, Cecilia; Bruni, Elena; Zagaglia, Carlo; Prosseda, Gianni; Nencioni, Lucia; Casalino, Mariassunta; Polticelli, Fabio; Nicoletti, Mauro

    2014-01-01

    Proper protein localization is critical for bacterial virulence. PhoN2 is a virulence-associated ATP-diphosphohydrolase (apyrase) involved in IcsA-mediated actin-based motility of S. flexneri. Herein, by analyzing a ΔphoN2 mutant of the S. flexneri strain M90T and by generating phoN2::HA fusions, we show that PhoN2, is a periplasmic protein that strictly localizes at the bacterial poles, with a strong preference for the old pole, the pole where IcsA is exposed, and that it is required for proper IcsA exposition. PhoN2-HA was found to be polarly localized both when phoN2::HA was ectopically expressed in a Escherichia coli K-12 strain and in a S. flexneri virulence plasmid-cured mutant, indicating a conserved mechanism of PhoN2 polar delivery across species and that neither IcsA nor the expression of other virulence-plasmid encoded genes are involved in this process. To assess whether PhoN2 and IcsA may interact, two-hybrid and cross-linking experiments were performed. While no evidence was found of a PhoN2-IcsA interaction, unexpectedly the outer membrane protein A (OmpA) was shown to bind PhoN2-HA through its periplasmic-exposed C-terminal domain. Therefore, to identify PhoN2 domains involved in its periplasmic polar delivery as well as in the interaction with OmpA, a deletion and a set of specific amino acid substitutions were generated. Analysis of these mutants indicated that neither the (183)PAPAP(187) motif of OmpA, nor the N-terminal polyproline (43)PPPP(46) motif and the Y155 residue of PhoN2 are involved in this interaction while P45, P46 and Y155 residues were found to be critical for the correct folding and stability of the protein. The relative rapid degradation of these amino acid-substituted recombinant proteins was found to be due to unknown S. flexneri-specific protease(s). A model depicting how the PhoN2-OmpA interaction may contribute to proper polar IcsA exposition in S. flexneri is presented.

  7. Shigella from Humans in Thailand During 1993 to 2006

    DEFF Research Database (Denmark)

    Bangtrakulnonth, A.; Wong, Danilo Lo Fo; Vieira, Antonio

    2008-01-01

    In Thailand during 1993-2006, a total of 9063 Shigella isolates from different medical centers were serotyped and trends over time and. spatial clustering analyzed. Of 3583 cases with age information, 1315 (37%) cases were from children between 0 and 4 years and 684 (1.9%) from children between 5...... and 8 years. Most infections were recorded during 1993-1994 (> 1500 per year), decreasing to Shigella flexneri accounted for 2241 (65%) of 3474 isolations. This proportion decreased to 64 (36%) of 176 infections in 2006....... Most infections occurred during July and August, and fewest in December. S. flexneri clustered around Bangkok, and Shigella sonnei in southern Thailand. Most S. flexneri infections were caused by serotype 2a (1590 of 4035) followed by serotype var X (1249). For both serotypes, a pronounced decrease...

  8. Prevalence and characterization of human Shigella infections in Henan Province, China, in 2006

    DEFF Research Database (Denmark)

    Xia, S.; Xu, B.; Huang, L.

    2011-01-01

    In 2006, 3531 fecal samples were collected from patients with diarrhea in Henan Province, China. A total of 467 (13.2%) Shigella strains were isolated and serotyped. Seventy-one Shigella flexneri strains were characterized by MIC determination, pulsed-field gel electrophoresis (PFGE), and detection...

  9. Mitochondria mediate septin cage assembly to promote autophagy of Shigella.

    Science.gov (United States)

    Sirianni, Andrea; Krokowski, Sina; Lobato-Márquez, Damián; Buranyi, Stephen; Pfanzelter, Julia; Galea, Dieter; Willis, Alexandra; Culley, Siân; Henriques, Ricardo; Larrouy-Maumus, Gerald; Hollinshead, Michael; Sancho-Shimizu, Vanessa; Way, Michael; Mostowy, Serge

    2016-07-01

    Septins, cytoskeletal proteins with well-characterised roles in cytokinesis, form cage-like structures around cytosolic Shigella flexneri and promote their targeting to autophagosomes. However, the processes underlying septin cage assembly, and whether they influence S. flexneri proliferation, remain to be established. Using single-cell analysis, we show that the septin cages inhibit S. flexneri proliferation. To study mechanisms of septin cage assembly, we used proteomics and found mitochondrial proteins associate with septins in S. flexneri-infected cells. Strikingly, mitochondria associated with S. flexneri promote septin assembly into cages that entrap bacteria for autophagy. We demonstrate that the cytosolic GTPase dynamin-related protein 1 (Drp1) interacts with septins to enhance mitochondrial fission. To avoid autophagy, actin-polymerising Shigella fragment mitochondria to escape from septin caging. Our results demonstrate a role for mitochondria in anti-Shigella autophagy and uncover a fundamental link between septin assembly and mitochondria. © 2016 The Authors. Published under the terms of the CC BY 4.0 license.

  10. Shigella Diversity and Changing Landscape: Insights for the Twenty-First Century

    Science.gov (United States)

    Anderson, Mark; Sansonetti, Philippe J.; Marteyn, Benoit S.

    2016-01-01

    Shigella is a pathovar of Escherichia coli comprising four groups, Shigella flexneri, Shigella sonnei, Shigella dysenteriae, and Shigella boydii, each of them, with the exception of S.sonnei, comprising several serotypes. Shigella accounts for the majority of dysentery causing infections occurring world-wide each year. Recent advancements in the Shigella field have led to a better understanding of the molecular mechanisms underlying host epithelial cell invasion and immune cell function manipulation, mainly using S. flexneri as a model. Host-cell invasion is the final step of the infection process, as Shigella's virulence strategy relies also on its ability to survive hostile conditions during its journey through the gastro-intestinal tract, to compete with the host microbiota and to cross the intestinal mucus layer. Hence, the diversity of the virulence strategies among the different Shigella species has not yet been deeply investigated, which might be an important step to understand the epidemiological spreading of Shigella species worldwide and a key aspect for the validation of novel vaccine candidates. The recent development of high-throughput screening and sequencing methods will facilitate these complex comparison studies. In this review we discuss several of the major avenues that the Shigella research field has taken over the past few years and hopefully gain some insights into the questions that remain surrounding this important human pathogen. PMID:27148494

  11. Defining the phylogenomics of Shigella species: a pathway to diagnostics.

    Science.gov (United States)

    Sahl, Jason W; Morris, Carolyn R; Emberger, Jennifer; Fraser, Claire M; Ochieng, John Benjamin; Juma, Jane; Fields, Barry; Breiman, Robert F; Gilmour, Matthew; Nataro, James P; Rasko, David A

    2015-03-01

    Shigellae cause significant diarrheal disease and mortality in humans, as there are approximately 163 million episodes of shigellosis and 1.1 million deaths annually. While significant strides have been made in the understanding of the pathogenesis, few studies on the genomic content of the Shigella species have been completed. The goal of this study was to characterize the genomic diversity of Shigella species through sequencing of 55 isolates representing members of each of the four Shigella species: S. flexneri, S. sonnei, S. boydii, and S. dysenteriae. Phylogeny inferred from 336 available Shigella and Escherichia coli genomes defined exclusive clades of Shigella; conserved genomic markers that can identify each clade were then identified. PCR assays were developed for each clade-specific marker, which was combined with an amplicon for the conserved Shigella invasion antigen, IpaH3, into a multiplex PCR assay. This assay demonstrated high specificity, correctly identifying 218 of 221 presumptive Shigella isolates, and sensitivity, by not identifying any of 151 diverse E. coli isolates incorrectly as Shigella. This new phylogenomics-based PCR assay represents a valuable tool for rapid typing of uncharacterized Shigella isolates and provides a framework that can be utilized for the identification of novel genomic markers from genomic data. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  12. Protective immunity by oral immunization with heat-killed Shigella strains in a guinea pig colitis model.

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    Barman, Soumik; Koley, Hemanta; Ramamurthy, Thandavarayan; Chakrabarti, Manoj Kumar; Shinoda, Sumio; Nair, Gopinath Balakrish; Takeda, Yoshifumi

    2013-11-01

    The protective efficacy of and immune response to heat-killed cells of monovalent and hexavalent mixtures of six serogroups/serotypes of Shigella strains (Shigella dysenteriae 1, Shigella flexneri 2a, S. flexneri 3a, S. flexneri 6, Shigella boydii 4, and Shigella sonnei) were examined in a guinea pig colitis model. A monovalent or hexavalent mixture containing 1 × 10(7) of each serogroup/serotype of heat-killed Shigella cells was administered orally on Days 0, 7, 14 and 21. On Day 28, the immunized animals were challenged rectally with 1 × 10(9) live virulent cells of each of the six Shigella serogroups/serotypes. In all immunized groups, significant levels of protection were observed after these challenges. The serum titers of IgG and IgA against the lipopolysaccharide of each of the six Shigella serogroups/serotypes increased exponential during the course of immunization. High IgA titers against the lipopolysaccharide of each of the six Shigella serogroups/serotypes were also observed in intestinal lavage fluid from all immunized animals. These data indicate that a hexavalent mixture of heat-killed cells of the six Shigella serogroups/serotypes studied would be a possible broad-spectrum candidate vaccine against shigellosis. © 2013 The Societies and Wiley Publishing Asia Pty Ltd.

  13. Shift in serotype distribution of Shigella species in China, 2003-2013.

    Science.gov (United States)

    Qiu, S; Xu, X; Yang, C; Wang, J; Liang, B; Li, P; Li, H; Yi, S; Liu, H; Cui, X; Wu, Z; Xie, J; Jia, L; Wang, L; Hao, R; Jin, H; Wang, Y; Sun, Y; Song, H

    2015-03-01

    We identified 2912 Shigella isolates from diarrhoeal patients in China during 2003-2013. The most common species was Shigella flexneri (55.3%), followed by Shigella sonnei (44.1%); however, S. sonnei is becoming increasingly prevalent. Among the S. flexneri isolates, serotypes 2a and X variant (-:7,8, E1037) were the two most prevalent serotypes, and serologically atypical isolates were also commonly identified. Overall, S. sonnei, S. flexneri 2a and S. flexneri X variant (-:7,8, E1037) accounted for 76.1% of all Shigella isolates, and their prevalence increased from 54.0% during 2003-2004 to 84.1% during 2011-2013. A change was observed in the serotype distribution of Shigella in China during this period, and we propose an ideal strategy to inform the development of a broadly effective Shigella vaccine candidate. Copyright © 2014 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

  14. Detection and analysis of CRISPRs of Shigella.

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    Guo, Xiangjiao; Wang, Yingfang; Duan, Guangcai; Xue, Zerun; Wang, Linlin; Wang, Pengfei; Qiu, Shaofu; Xi, Yuanlin; Yang, Haiyan

    2015-01-01

    The recently discovered CRISPRs (Clustered regularly interspaced short palindromic repeats) and Cas (CRISPR-associated) proteins are a novel genetic barrier that limits horizontal gene transfer in prokaryotes and the CRISPR loci provide a historical view of the exposure of prokaryotes to a variety of foreign genetic elements. The aim of study was to investigate the occurrence and distribution of the CRISPRs in Shigella. A collection of 61 strains of Shigella were screened for the existence of CRISPRs. Three CRISPR loci were identified among 61 shigella strains. CRISPR1/cas loci are detected in 49 strains of shigella. Yet, IS elements were detected in cas gene in some strains. In the remaining 12 Shigella flexneri strains, the CRISPR1/cas locus is deleted and only a cas3' pseudo gene and a repeat sequence are present. The presence of CRISPR2 is frequently accompanied by the emergence of CRISPR1. CRISPR3 loci were present in almost all strains (52/61). The length of CRISPR arrays varied from 1 to 9 spacers. Sequence analysis of the CRISPR arrays revealed that few spacers had matches in the GenBank databases. However, one spacer in CRISPR3 loci matches the cognate cas3 genes and no cas gene was present around CRISPR3 region. Analysis of CRISPR sequences show that CRISPR have little change which makes CRISPR poor genotyping markers. The present study is the first attempt to determine and analyze CRISPRs of shigella isolated from clinical patients.

  15. Serogrupos y susceptibilidad antimicrobiana en cepas de Shigella Serogroups and antimicrobial susceptibility in Shigella strains

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    Leonor Díaz Rigau

    2009-03-01

    Full Text Available INTRODUCCIÓN. Shigella spp. es uno de los agentes causales más importantes de diarrea aguda en los niños. La presente investigación tuvo como objetivo conocer la frecuencia de serogrupos y la susceptibilidad antimicrobiana a los fármacos de elección y a los alternativos. MÉTODOS. Se realizó un estudio descriptivo y retrospectivo entre enero de 2004 y diciembre de 2006 a partir de 34 cepas de Shigella spp. aisladas en heces de niños menores de 5 años ingresados en el Hospital «Aleida Fernández Chardiet» (Municipio Güines a causa de enfermedad diarreica aguda. RESULTADOS. Los serogrupos encontrados fueron S. sonnei (70,5 % y S. flexneri (29,5 %. Ambos serogrupos mostraron altos niveles de resistencia al trimetoprim-sulfametoxazol y a la ampicilina, además en las cepas de S. sonnei se encontró resistencia al ácido nalidíxico y en las de S. flexneri al cloranfenicol. Todas las cepas mostraron altos porcentajes de sensibilidad a la ceftriaxona, norfloxacina y ciprofloxacina. El 70 % de las cepas de S. sonnei fueron multirresistentes. El patrón de multirresistencia (ampicilina, trimetoprim-sulfamtetoxazol y ácido nalidíxico se encontró en ambos serogrupos. CONCLUSIONES. La determinación y vigilancia de los patrones de resistencia facilita el control de la política de uso de antibióticos en la región estudiada y previene el surgimiento de cepas resistentes a fármacos de nueva generación.INTRODUCTION: Shigella ssp. is one of the more important causal agents of acute diarrhea in children. Present research has as aim to know serogroups frequency and antimicrobial susceptibility to choice drugs, and to its alternatives. METHODS: A descriptive retrospective study was carried out between January 2004 and December 2006 of 34 strains of Shigella isolated from children lower than 5 years admitted in "Aleida Fernández Chardiet" Hospital in Güines Municipality by acute diarrheic disease. RESULTS: Serogroups included S. sonnei (70

  16. Relationship among Shigella spp. and enteroinvasive Escherichia coli (EIEC) and their differentiation.

    Science.gov (United States)

    Ud-Din, Abu; Wahid, Syeda

    2014-01-01

    Shigellosis produces inflammatory reactions and ulceration on the intestinal epithelium followed by bloody or mucoid diarrhea. It is caused by enteroinvasive E. coli (EIEC) as well as any species of the genus Shigella, namely, S. dysenteriae, S. flexneri, S. boydii, and S. sonnei. This current species designation of Shigella does not specify genetic similarity. Shigella spp. could be easily differentiated from E. coli, but difficulties observed for the EIEC-Shigella differentiation as both show similar biochemical traits and can cause dysentery using the same mode of invasion. Sequencing of multiple housekeeping genes indicates that Shigella has derived on several different occasions via acquisition of the transferable forms of ancestral virulence plasmids within commensal E. coli and form a Shigella-EIEC pathovar. EIEC showed lower expression of virulence genes compared to Shigella, hence EIEC produce less severe disease than Shigella spp. Conventional microbiological techniques often lead to confusing results concerning the discrimination between EIEC and Shigella spp. The lactose permease gene (lacY) is present in all E. coli strains but absent in Shigella spp., whereas β-glucuronidase gene (uidA) is present in both E. coli and Shigella spp. Thus uidA gene and lacY gene based duplex real-time PCR assay could be used for easy identification and differentiation of Shigella spp. from E. coli and in particular EIEC.

  17. Molecular characterization of Shigella spp. from patients in Gabon 2011-2013.

    Science.gov (United States)

    Schaumburg, Frieder; Alabi, Abraham S; Kaba, Harry; Lell, Bertrand; Becker, Karsten; Grobusch, Martin P; Kremsner, Peter G; Mellmann, Alexander

    2015-04-01

    Shigella spp. dysentery is widespread in developing countries; the incidence is particularly high in children between 1-2 years of age. In sub-Saharan Africa, there is a paucity of epidemiological data on Shigella spp., with possible negative consequences for recognition and correct treatment choice for this life-threatening bacterial infection. We therefore characterized Shigella spp. isolates from Gabon. The antimicrobial resistance, virulence factors, genotypes and mobile genetic elements of Shigella isolates (29 S. flexneri; 5 S. boydii; 3 S. sonnei) from a retrospective strain collection were analyzed. High resistance rates were found for gentamicin and tetracycline (100%, 37/37), cotrimoxazole (92%, 34/37) and ampicillin (84%, 31/37). All isolate harbored ial and ipaH; no isolate produced Shiga toxins (stx1/2); enterotoxins (set1A/B) were only found in S. flexneri (n=19). Multilocus sequence types (MLST) clustered with global clones. A high prevalence of atypical class 1 integrons harboring blaOXA30 and aadA1 were detected in S. flexneri, while all S. sonnei carried class 2 integrons. There is a strong link of Gabonese Shigella spp. isolates with pandemic lineages as they cluster with major global clones and frequently carry atypical class 1 integrons which are frequently reported in Shigella spp. from Asia. © The Author 2014. Published by Oxford University Press on behalf of Royal Society of Tropical Medicine and Hygiene. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  18. Virulotyping of Shigella spp. isolated from pediatric patients in Tehran, Iran.

    Science.gov (United States)

    Ranjbar, Reza; Bolandian, Masomeh; Behzadi, Payam

    2017-03-01

    Shigellosis is a considerable infectious disease with high morbidity and mortality among children worldwide. In this survey the prevalence of four important virulence genes including ial, ipaH, set1A, and set1B were investigated among Shigella strains and the related gene profiles identified in the present investigation, stool specimens were collected from children who were referred to two hospitals in Tehran, Iran. The samples were collected during 3 years (2008-2010) from children who were suspected to shigellosis. Shigella spp. were identified throughout microbiological and serological tests and then subjected to PCR for virulotyping. Shigella sonnei was ranking first (65.5%) followed by Shigella flexneri (25.9%), Shigella boydii (6.9%), and Shigella dysenteriae (1.7%). The ial gene was the most frequent virulence gene among isolated bacterial strains and was followed by ipaH, set1B, and set1A. S. flexneri possessed all of the studied virulence genes (ial 65.51%, ipaH 58.62%, set1A 12.07%, and set1B 22.41%). Moreover, the pattern of virulence gene profiles including ial, ial-ipaH, ial-ipaH-set1B, and ial-ipaH-set1B-set1A was identified for isolated Shigella spp. strains. The pattern of virulence genes is changed in isolated strains of Shigella in this study. So, the ial gene is placed first and the ipaH in second.

  19. Laboratory monitoring of bacterial gastroenteric pathogens Salmonella and Shigella in Shanghai, China 2006-2012.

    Science.gov (United States)

    Zhang, J; Wang, F; Jin, H; Hu, J; Yuan, Z; Shi, W; Yang, X; Meng, J; Xu, X

    2015-02-01

    In 2006 we initiated an enhanced laboratory-based surveillance of Salmonella and Shigella infections in Shanghai, China. A total of 4483 Salmonella and 2226 Shigella isolates were recovered from stool specimens by 2012. In 80 identified Salmonella serovars, Enteritidis (34·5%) and Typhimurium (26·2%) were the most common. Shigella (S.) sonnei accounted for 63·9% of human Shigella infections over the same time period, and replaced S. flexneri to become the primary cause of shigellosis since 2010. Overall, a high level of antimicrobial resistance was observed in Salmonella and Shigella, particularly to nalidixic acid, ampicillin, and tetracycline. Ciprofloxacin resistance was common in Salmonella Typhimurium (21·0%) and S. flexneri (37·6%). The cephalosporin resistance in both pathogens also increased over the years, ranging from 3·4% to 7·0% in Salmonella, and from 10·4% to 28·6% in Shigella. Resistance to multiple antimicrobials was also identified in a large number of the isolates. This study provides insight into the distribution of Salmonella and Shigella in diarrhoeal diseases.

  20. Antimicrobial resistence of Shigella species isolated during 2004 and 2005 from selected sites in Zimbabwe.

    Science.gov (United States)

    Ndlovu, N; Tarupiwa, A; Mudzori, J T

    2006-01-01

    To determine the predominant serotype and antibiotic sensitivity pattern of Shigella isolates during 2004 and 2005 in Zimbabwe. Cross sectional study. National Microbiology Reference Laboratory (NMRL), Harare, Zimbabwe. 259 clinical isolates of Shigella species isolated during 2004 and 2005 in Zimbabwe were studied. These samples had been referred to the NMRL for further testing. Serotype and antibiotic sensitivity pattern of Shigella species. Of the 259 clinical isolates of Shigella tested the following species were serotyped; 141 (54.4%) were S. flexneri; 70 (27%) S. sonnei; 38 (14.7%) S. dysenteriae and 10 (3.9%) S. boydii. About 4% of all Shigella isolates tested showed full sensitivity to commonly used antibiotics, 20.8% were resistant to one antibiotic only while 75.3% were resistant to at least two antibiotics. The most common resistance among Shigella species was to cotrimoxazole (89%), tetracycline (73%), ampicillin (49%) and chloramphenicol (41%). High susceptibility among Shigella species was observed to nalidixic acid (86%), ciprofloxacin (99%) and ceftazidine (99%). There was a low drug resistance of Shigella species to nalidixic acid, a drug of choice in Zimbabwe, except among Shigella dysenteriae type 1 strains. Continuous monitoring of the susceptibility patterns of Shigella species is important in order to detect the emergence of drug resistance and to update guidelines for antibiotic treatment in shigellosis.

  1. Status of vaccine research and development for Shigella.

    Science.gov (United States)

    Mani, Sachin; Wierzba, Thomas; Walker, Richard I

    2016-06-03

    Shigella are gram-negative bacteria that cause severe diarrhea and dysentery. In 2013, Shigella infections caused an estimated 34,400 deaths in children less than five years old and, in 2010, an estimated 40,000 deaths in persons older than five years globally. New disease burden estimates from newly deployed molecular diagnostic assays with increased sensitivity suggest that Shigella-associated morbidity may be much greater than previous disease estimates from culture-based methods. Primary prevention of this disease should be based on universal provision of potable water and sanitation methods and improved personal and food hygiene. However, an efficacious and low-cost vaccine would complement and accelerate disease reduction while waiting for universal access to water, sanitation, and hygiene improvements. This review article provides a landscape of Shigella vaccine development efforts. No vaccine is yet available, but human and animal challenge-rechallenge trials with virulent Shigella as well as observational studies in Shigella-endemic areas have shown that the incidence of disease decreases following Shigella infection, pointing to biological feasibility of a vaccine. Immunity to Shigella appears to be strain-specific, so a vaccine that covers the most commonly detected strains (i.e., S. flexneri 2a, 3a, 6, and S. sonnei) or a vaccine using cross-species conserved antigens would likely be most effective. Vaccine development and testing may be accelerated by use of animal models, such as the guinea pig keratoconjunctivitis or murine pneumonia models. Because there is no correlate of protection, however, human studies will be necessary to evaluate vaccine efficacy prior to deployment. A diversity of Shigella vaccine constructs are under development, including live attenuated, formalin-killed whole-cell, glycoconjugate, subunit, and novel antigen vaccines (e.g., Type III secretion system and outer membrane proteins). Copyright © 2016 World Health Organization

  2. Shigella reroutes host cell central metabolism to obtain high-flux nutrient supply for vigorous intracellular growth.

    Science.gov (United States)

    Kentner, David; Martano, Giuseppe; Callon, Morgane; Chiquet, Petra; Brodmann, Maj; Burton, Olga; Wahlander, Asa; Nanni, Paolo; Delmotte, Nathanaël; Grossmann, Jonas; Limenitakis, Julien; Schlapbach, Ralph; Kiefer, Patrick; Vorholt, Julia A; Hiller, Sebastian; Bumann, Dirk

    2014-07-08

    Shigella flexneri proliferate in infected human epithelial cells at exceptionally high rates. This vigorous growth has important consequences for rapid progression to life-threatening bloody diarrhea, but the underlying metabolic mechanisms remain poorly understood. Here, we used metabolomics, proteomics, and genetic experiments to determine host and Shigella metabolism during infection in a cell culture model. The data suggest that infected host cells maintain largely normal fluxes through glycolytic pathways, but the entire output of these pathways is captured by Shigella, most likely in the form of pyruvate. This striking strategy provides Shigella with an abundant favorable energy source, while preserving host cell ATP generation, energy charge maintenance, and survival, despite ongoing vigorous exploitation. Shigella uses a simple three-step pathway to metabolize pyruvate at high rates with acetate as an excreted waste product. The crucial role of this pathway for Shigella intracellular growth suggests targets for antimicrobial chemotherapy of this devastating disease.

  3. The Galleria mellonella larvae as an in vivo model for evaluation of Shigella virulence.

    Science.gov (United States)

    Barnoy, Shoshana; Gancz, Hanan; Zhu, Yuewei; Honnold, Cary L; Zurawski, Daniel V; Venkatesan, Malabi M

    2017-07-04

    Shigella spp. causing bacterial diarrhea and dysentery are human enteroinvasive bacterial pathogens that are orally transmitted through contaminated food and water and cause bacillary dysentery. Although natural Shigella infections are restricted to humans and primates, several smaller animal models are used to analyze individual steps in pathogenesis. No animal model fully duplicates the human response and sustaining the models requires expensive animals, costly maintenance of animal facilities, veterinary services and approved animal protocols. This study proposes the development of the caterpillar larvae of Galleria mellonella as a simple, inexpensive, informative, and rapid in-vivo model for evaluating virulence and the interaction of Shigella with cells of the insect innate immunity. Virulent Shigella injected through the forelegs causes larvae death. The mortality rates were dependent on the Shigella strain, the infectious dose, and the presence of the virulence plasmid. Wild-type S. flexneri 2a, persisted and replicated within the larvae, resulting in haemocyte cell death, whereas plasmid-cured mutants were rapidly cleared. Histology of the infected larvae in conjunction with fluorescence, immunofluorescence, and transmission electron microscopy indicate that S. flexneri reside within a vacuole of the insect haemocytes that ultrastructurally resembles vacuoles described in studies with mouse and human macrophage cell lines. Some of these bacteria-laden vacuoles had double-membranes characteristic of autophagosomes. These results suggest that G. mellonella larvae can be used as an easy-to-use animal model to understand Shigella pathogenesis that requires none of the time and labor-consuming procedures typical of other systems.

  4. An eight-year study of Shigella species in Beijing, China: serodiversity, virulence genes, and antimicrobial resistance.

    Science.gov (United States)

    Qu, Mei; Zhang, Xin; Liu, Guirong; Huang, Ying; Jia, Lei; Liang, Weili; Li, Xitai; Wu, Xiaona; Li, Jie; Yan, Hanqiu; Kan, Biao; Wang, Quanyi

    2014-07-14

    This study was conducted to determine the prevalence of serotypes, virulence factors, and antimicrobial resistance patterns of Shigella spp. in Beijing, China, from 2004 to 2011. Real-time PCR assays were used to detect virulent genes, and the Kirby-Bauer disk diffusion method was used to evaluate antimicrobial resistance. Among the total of 1,652 Shigella isolates, S. sonnei (57.1%) was the predominant species, followed by S. flexneri (42.3%), S. dysenteriae (0.4%), and S. boydii (0.2%). Nineteen serotypes were discovered among S. flexneri strains. The virulence gene ipaH was the most frequent, followed by sen and set. The presence of set showed significant difference in two dominant serogroups, S. flexneri and S. sonnei. Over 90% of Shigella isolates showed resistance to at least three drugs with widened spectrum. High-level antimicrobial resistance to single and multiple antibiotics was more common among S. sonnei than S. flexneri. There was an obvious serotype change and a dramatic increase of antibiotic resistance in Shigella prevalence in Beijing.

  5. Risk factors and outcome of Shigella encephalopathy in Bangladeshi children.

    Directory of Open Access Journals (Sweden)

    Farzana Afroze

    2017-04-01

    Full Text Available Although, Shigella encephalopathy, a serious extra-intestinal complication of shigellosis, significantly increases the risks of death, data are very limited on predicting factors particularly related to electrolyte profiles in children below five years of age with Shigella encephalopathy. Our objective was to determine the clinical as well as laboratory predicting factors and outcome of children with Shigella encephalopathy.In this unmatched case-control design, children aged 2-59 months having a positive stool culture for Shigella and who had their serum electrolytes been done from July 2012 to June 2015 were studied. Children with Shigella encephalopathy, defined as having abnormal mentation, constituted the cases, and those without encephalopathy constituted the controls. During the study period, we identified a total of 541 children less than five years of age, who had Shigella in their stool culture. Only 139 children fulfilled the study criteria and among them 69 were cases and 70 were controls. The cases more often had fatal outcome compared to the controls (7% vs. 0%, P = 0.02. In logistic regression analysis, the cases were independently associated with shorter duration (1.2 ± 0.4 days of diarrhea prior to admission, dehydrating diarrhea, sepsis and hyponatremia (p<0.05 for all. Among 139 Shigella isolates, S. flexneri (88/139, 63% and S. sonnei(34/139, 24% were the dominant species. S. dysenteriae was not isolated throughout the study period. S.sonnei was more frequently isolated from the cases (24/69, 35% than the controls (10/70, 14%, whereas the isolation of S. flexneri was comparable between the groups (40/69, 58% vs 48/70, 69%. A total of 94 (67.6% isolates were resistant to trimethoprim-sulphamethoxazole, 84 (60.4% to ciprofloxacin, 66/138 (48% to ampicillin, 5 (3.5% to ceftriaxone, 17 (12.2% to mecillinum and 35 (25% to azithromycin.The case-fatality-rate was significantly higher among the children with Shigella encephalopathy

  6. Shigella infection in children under 5 years old in western French Guiana.

    Science.gov (United States)

    Parisot, M; Parez, N; Boukhari, R; Breurec, S; Jolivet, A

    2018-04-15

    French Guiana, a tropical country, is characterised by a young and multi-ethnic population. Difficulties in accessing safe water sources lead to outbreaks of gastroenteritis. The objectives of this study were (1) to describe the microbiological profile of shigella strains isolated in western French Guiana, including antimicrobial susceptibility and the distribution of strains in terms of species and serotypes and (2) to estimate the incidence of shigellosis in children under 5 years old. A retrospective observational study was conducted of 213 cases of shigellosis diagnosed in the biology department of the hospital centre for western French Guiana between 2000 and 2012 in children under 5 years old. The serogroups (formerly known as species) that predominates in French Guiana was Shigella flexneri. No resistance was observed to fluoroquinolones or to third-generation cephalosporins. The average incidence of shigellosis in children under 5 years old in western French Guiana was estimated at 189.6 cases per 100 000 inhabitants per year. Shigellosis is a public health problem in western French Guiana. These infections suggest the difficulties in accessing safe water sources and the lack of public sanitation. A quadrivalent vaccine containing Shigella sonnei and three serotypes of S. flexneri (S. flexneri 2a, 3a and 6) could provide broad coverage against shigella infections.

  7. Failure of Syndrome-Based Diarrhea Management Guidelines to Detect Shigella Infections in Kenyan Children.

    Science.gov (United States)

    Pavlinac, P B; Denno, D M; John-Stewart, G C; Onchiri, F M; Naulikha, J M; Odundo, E A; Hulseberg, C E; Singa, B O; Manhart, L E; Walson, J L

    2016-12-01

    Shigella is a leading cause of childhood diarrhea mortality in sub-Saharan Africa. Current World Health Organization guidelines recommend antibiotics for children in non cholera-endemic areas only in the presence of dysentery, a proxy for suspected Shigella infection. To assess the sensitivity and specificity of the syndromic diagnosis of Shigella-associated diarrhea, we enrolled children aged 6 months to 5 years presenting to 1 of 3 Western Kenya hospitals between November 2011 and July 2014 with acute diarrhea. Stool samples were tested using standard methods for bacterial culture and multiplex polymerase chain reaction for pathogenic Escherichia coli. Stepwise multivariable logit models identified factors to increase the sensitivity of syndromic diagnosis. Among 1360 enrolled children, median age was 21 months (interquartile range, 11-37), 3.4% were infected with human immunodeficiency virus, and 16.5% were stunted (height-for-age z-score less than -2). Shigella was identified in 63 children (4.6%), with the most common species being Shigella sonnei (53.8%) and Shigella flexneri (40.4%). Dysentery correctly classified 7 of 63 Shigella cases (sensitivity, 11.1%). Seventy-eight of 1297 children without Shigella had dysentery (specificity, 94.0%). The combination of fecal mucous, age over 23 months, and absence of excessive vomiting identified more children with Shigella-infection (sensitivity, 39.7%) but also indicated antibiotics in more children without microbiologically confirmed Shigella (specificity, 82.7%). Reliance on dysentery as a proxy for Shigella results in the majority of Shigella-infected children not being identified for antibiotics. Field-ready rapid diagnostics or updated evidence-based algorithms are urgently needed to identify children with diarrhea most likely to benefit from antibiotic therapy. © The Author 2015. Published by Oxford University Press on behalf of the Pediatric Infectious Diseases Society. All rights reserved. For Permissions

  8. Molecular characterization of multidrug-resistant Shigella spp. of food origin.

    Science.gov (United States)

    Ahmed, Ashraf M; Shimamoto, Tadashi

    2015-02-02

    Shigella spp. are the causative agents of food-borne shigellosis, an acute enteric infection. The emergence of multidrug-resistant clinical isolates of Shigella presents an increasing challenge for clinicians in the treatment of shigellosis. Several studies worldwide have characterized the molecular basis of antibiotic resistance in clinical Shigella isolates of human origin, however, to date, no such characterization has been reported for Shigella spp. of food origin. In this study, we characterized the genetic basis of multidrug resistance in Shigella spp. isolated from 1600 food samples (800 meat products and 800 dairy products) collected from different street venders, butchers, retail markets, and slaughterhouses in Egypt. Twenty-four out of 27 Shigella isolates (88.9%) showed multidrug resistance phenotypes to at least three classes of antimicrobials. The multidrug-resistant Shigella spp. were as follows: Shigella flexneri (66.7%), Shigella sonnei (18.5%), and Shigella dysenteriae (3.7%). The highest resistance was to streptomycin (100.0%), then to kanamycin (95.8%), nalidixic acid (95.8%), tetracycline (95.8%), spectinomycin (93.6%), ampicillin (87.5%), and sulfamethoxazole/trimethoprim (87.5%). PCR and DNA sequencing were used to screen and characterize integrons and antibiotic resistance genes. Our results indicated that 11.1% and 74.1% of isolates were positive for class 1 and class 2 integrons, respectively. Beta-lactamase-encoding genes were identified in 77.8% of isolates, and plasmid-mediated quinolone resistance genes were identified in 44.4% of isolates. These data provide useful information to better understand the molecular basis of antimicrobial resistance in Shigella spp. To the best of our knowledge, this is the first report of the molecular characterization of antibiotic resistance in Shigella spp. isolated from food. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Characterization of Shigella Strains by Plasmid Profile Analysis and Antibiotic Susceptibility Patterns in a Pediatric Hospital in Ahvaz

    Directory of Open Access Journals (Sweden)

    Amin Sakhaei

    2015-11-01

    Full Text Available Background: High incidences of dysentery and diarrhea were reported in a pediatric hospital in Ahvaz, Iran during March to April, 2013. Objectives: A cross-sectional study was therefore undertaken to identify the causative agents. Patients and Methods: A total of 230 diarrhea samples were collected from the patients and analyzed by routine bacteriological methods. Bacterial identification, serological assay, antimicrobial susceptibility testing, extended spectrum β-lactamases (ESBLs screening and plasmid profile analysis were performed according to the standard guidelines. Results: A total of 70 Shigella strains including %70 (n = 49 S. sonnei and 30% (n = 21 S. flexneri were isolated from diarrhea samples. Most of the Shigella isolates showed high degrees of resistance to ampicillin, ulafamethoxazole- trimethoprime and cefexim. Concurrent resistance to sulafametoxazole- trimethoprime and ampicillin was the most common resistance pattern. Overall, 11.4% of Shigella isolates showed the ESBL producer criteria. The plasmid profile patterns of all the strains were determined by a modified alkaline lysis method. By plasmid profile analysis 23 genotypes were identified among all the isolates, 14 and 9 genotypes among the S. sonnei and S. Flexneri respectively. S. sonnei and S. flexneri isolates demonstrated unique plasmid profiles. Conclusions: These data demonstrated that S. sonnei strains are the main cause of shigellosis as the prevalent Shigella serotype in Iran. We also found that the antibiotic resistance rates are increasing among Shigella strains. Plasmid profile analysis is more reliable than antibiotic susceptibility patterns in epidemiologic studies.

  10. Occurrence of integrons and resistance genes among sulphonamide-resistant Shigella spp. from Brazil

    DEFF Research Database (Denmark)

    Peirano, G.; Agersø, Yvonne; Aarestrup, Frank Møller

    2005-01-01

    Objectives: To determine the occurrence of class 1 and 2 integrons and antimicrobial resistance genes among sulphonamide-resistant Shigella strains isolated in Brazil during 1999-2003. Methods: Sixty-two Shigella (Shigella flexneri, n = 47 and Shigella sonnei, n = 15) were tested against 21...... antimicrobial agents. The presence of integrons classes 1 and 2 and antimicrobial resistance genes was investigated by PCR using specific primers. Results: A total of eight antimicrobial resistance profiles were identified, with the profile of resistance to sulfamethoxazole, trimethoprim, spectinomycin...... of 2214 bp harbouring a gene cassette array conferring resistance to trimethoprim, streptothricin and spectinomycin/streptomycin. The genes coding for resistance to chloramphenicol (catA1), tetracycline [tet(A) and tet(B)] and ampicillin (bla(OXA) and bla(TEM)), were detected in resistant strains...

  11. PI5P Triggers ICAM-1 Degradation in Shigella Infected Cells, Thus Dampening Immune Cell Recruitment

    Directory of Open Access Journals (Sweden)

    Frédéric Boal

    2016-02-01

    Full Text Available Shigella flexneri, the pathogen responsible for bacillary dysentery, has evolved multiple strategies to control the inflammatory response. Here, we show that Shigella subverts the subcellular trafficking of the intercellular adhesion molecule-1 (ICAM-1, a key molecule in immune cell recruitment, in a mechanism dependent on the injected bacterial enzyme IpgD and its product, the lipid mediator PI5P. Overexpression of IpgD, but not a phosphatase dead mutant, induced the internalization and the degradation of ICAM-1 in intestinal epithelial cells. Remarkably, addition of permeant PI5P reproduced IpgD effects and led to the inhibition of neutrophil recruitment. Finally, these results were confirmed in an in vivo model of Shigella infection where IpgD-dependent ICAM-1 internalization reduced neutrophil adhesion. In conclusion, we describe here an immune evasion mechanism used by the pathogen Shigella to divert the host cell trafficking machinery in order to reduce immune cell recruitment.

  12. An attenuated Shigella mutant lacking the RNA-binding protein Hfq provides cross-protection against Shigella strains of broad serotype.

    Science.gov (United States)

    Mitobe, Jiro; Sinha, Ritam; Mitra, Soma; Nag, Dhrubajyoti; Saito, Noriko; Shimuta, Ken; Koizumi, Nobuo; Koley, Hemanta

    2017-07-01

    Few live attenuated vaccines protect against multiple serotypes of bacterial pathogen because host serotype-specific immune responses are limited to the serotype present in the vaccine strain. Here, immunization with a mutant of Shigella flexneri 2a protected guinea pigs against subsequent infection by S. dysenteriae type 1 and S. sonnei strains. This deletion mutant lacked the RNA-binding protein Hfq leading to increased expression of the type III secretion system via loss of regulation, resulting in attenuation of cell viability through repression of stress response sigma factors. Such increased antigen production and simultaneous attenuation were expected to elicit protective immunity against Shigella strains of heterologous serotypes. Thus, the vaccine potential of this mutant was tested in two guinea pig models of shigellosis. Animals vaccinated in the left eye showed fewer symptoms upon subsequent challenge via the right eye, and even survived subsequent intestinal challenge. In addition, oral vaccination effectively induced production of immunoglobulins without severe side effects, again protecting all animals against subsequent intestinal challenge with S. dysenteriae type 1 or S. sonnei strains. Antibodies against common virulence proteins and the O-antigen of S. flexneri 2a were detected by immunofluorescence microscopy. Reaction of antibodies with various strains, including enteroinvasive Escherichia coli, suggested that common virulence proteins induced protective immunity against a range of serotypes. Therefore, vaccination is expected to cover not only the most prevalent serotypes of S. sonnei and S. flexneri 2a, but also various Shigella strains, including S. dysenteriae type 1, which produces Shiga toxin.

  13. Identification of Escherichia coli and Shigella Species from Whole-Genome Sequences.

    Science.gov (United States)

    Chattaway, Marie A; Schaefer, Ulf; Tewolde, Rediat; Dallman, Timothy J; Jenkins, Claire

    2017-02-01

    Escherichia coli and Shigella species are closely related and genetically constitute the same species. Differentiating between these two pathogens and accurately identifying the four species of Shigella are therefore challenging. The organism-specific bioinformatics whole-genome sequencing (WGS) typing pipelines at Public Health England are dependent on the initial identification of the bacterial species by use of a kmer-based approach. Of the 1,982 Escherichia coli and Shigella sp. isolates analyzed in this study, 1,957 (98.4%) had concordant results by both traditional biochemistry and serology (TB&S) and the kmer identification (ID) derived from the WGS data. Of the 25 mismatches identified, 10 were enteroinvasive E. coli isolates that were misidentified as Shigella flexneri or S. boydii by the kmer ID, and 8 were S. flexneri isolates misidentified by TB&S as S. boydii due to nonfunctional S. flexneri O antigen biosynthesis genes. Analysis of the population structure based on multilocus sequence typing (MLST) data derived from the WGS data showed that the remaining discrepant results belonged to clonal complex 288 (CC288), comprising both S. boydii and S. dysenteriae strains. Mismatches between the TB&S and kmer ID results were explained by the close phylogenetic relationship between the two species and were resolved with reference to the MLST data. Shigella can be differentiated from E. coli and accurately identified to the species level by use of kmer comparisons and MLST. Analysis of the WGS data provided explanations for the discordant results between TB&S and WGS data, revealed the true phylogenetic relationships between different species of Shigella, and identified emerging pathoadapted lineages. © Crown copyright 2017.

  14. Effect of wild-type Shigella species and attenuated Shigella vaccine candidates on small intestinal barrier function, antigen trafficking, and cytokine release.

    Directory of Open Access Journals (Sweden)

    Maria Fiorentino

    Full Text Available Bacterial dysentery due to Shigella species is a major cause of morbidity and mortality worldwide. The pathogenesis of Shigella is based on the bacteria's ability to invade and replicate within the colonic epithelium, resulting in severe intestinal inflammatory response and epithelial destruction. Although the mechanisms of pathogenesis of Shigella in the colon have been extensively studied, little is known on the effect of wild-type Shigella on the small intestine and the role of the host response in the development of the disease. Moreover, to the best of our knowledge no studies have described the effects of apically administered Shigella flexneri 2a and S. dysenteriae 1 vaccine strains on human small intestinal enterocytes. The aim of this study was to assess the coordinated functional and immunological human epithelial responses evoked by strains of Shigella and candidate vaccines on small intestinal enterocytes. To model the interactions of Shigella with the intestinal mucosa, we apically exposed monolayers of human intestinal Caco2 cells to increasing bacterial inocula. We monitored changes in paracellular permeability, examined the organization of tight-junctions and the pro-inflammatory response of epithelial cells. Shigella infection of Caco2 monolayers caused severe mucosal damage, apparent as a drastic increase in paracellular permeability and disruption of tight junctions at the cell-cell boundary. Secretion of pro-inflammatory IL-8 was independent of epithelial barrier dysfunction. Shigella vaccine strains elicited a pro-inflammatory response without affecting the intestinal barrier integrity. Our data show that wild-type Shigella infection causes a severe alteration of the barrier function of a small intestinal cell monolayer (a proxy for mucosa and might contribute (along with enterotoxins to the induction of watery diarrhea. Diarrhea may be a mechanism by which the host attempts to eliminate harmful bacteria and transport them

  15. Frequency of serovars and antimicrobial resistance in Shigella spp. from Brazil

    Directory of Open Access Journals (Sweden)

    Gisele Peirano

    2006-05-01

    Full Text Available A total of 296 Shigella spp. were received from State Public Health Laboratories, during the period from 1999 to 2004, by National Reference Laboratory for Cholera and Enteric Diseases (NRLCED - IOC/Fiocruz, Rio de Janeiro, Brazil. The frequency of Shigella spp. was: S. flexneri (52.7%, S. sonnei (44.2%, S. boydii (2.3%, and S. dysenteriae (0.6%. The most frequent S. flexneri serovars were 2a and 1b. The highest incidence rates of Shigella isolation were observed in the Southeast (39% and Northeast (34% regions and the lowest rate in the South (3% of Brazil. Strains were further analyzed for antimicrobial susceptibility by disk diffusion method as part of a surveillance program on antimicrobial resistance. The highest rates of antimicrobial resistance were to trimethoprim-sulfamethozaxole (90%, tetracycline (88%, ampicillin (56%, and chloramphenicol (35%. The patterns of antimicrobial resistance among Shigella isolates pose a major difficulty in the determination of an appropriate drug for shigellosis treatment. Continuous monitoring of antimicrobial susceptibilities of Shigella spp. through a surveillance system is thus essential for effective therapy and control measures against shigellosis.

  16. An Approach to Identify and Characterize a Subunit Candidate Shigella Vaccine Antigen.

    Science.gov (United States)

    Pore, Debasis; Chakrabarti, Manoj K

    2016-01-01

    Shigellosis remains a serious issue throughout the developing countries, particularly in children under the age of 5. Numerous strategies have been tested to develop vaccines targeting shigellosis; unfortunately despite several years of extensive research, no safe, effective, and inexpensive vaccine against shigellosis is available so far. Here, we illustrate in detail an approach to identify and establish immunogenic outer membrane proteins from Shigella flexneri 2a as subunit vaccine candidates.

  17. Shigella mediated depletion of macrophages in a murine breast cancer model is associated with tumor regression.

    Directory of Open Access Journals (Sweden)

    Katharina Galmbacher

    Full Text Available A tumor promoting role of macrophages has been described for a transgenic murine breast cancer model. In this model tumor-associated macrophages (TAMs represent a major component of the leukocytic infiltrate and are associated with tumor progression. Shigella flexneri is a bacterial pathogen known to specificly induce apotosis in macrophages. To evaluate whether Shigella-induced removal of macrophages may be sufficient for achieving tumor regression we have developed an attenuated strain of S. flexneri (M90TDeltaaroA and infected tumor bearing mice. Two mouse models were employed, xenotransplantation of a murine breast cancer cell line and spontanous breast cancer development in MMTV-HER2 transgenic mice. Quantitative analysis of bacterial tumor targeting demonstrated that attenuated, invasive Shigella flexneri primarily infected TAMs after systemic administration. A single i.v. injection of invasive M90TDeltaaroA resulted in caspase-1 dependent apoptosis of TAMs followed by a 74% reduction in tumors of transgenic MMTV-HER-2 mice 7 days post infection. TAM depletion was sustained and associated with complete tumor regression.These data support TAMs as useful targets for antitumor therapy and highlight attenuated bacterial pathogens as potential tools.

  18. Investigating Shigella sonnei Infections

    Centers for Disease Control (CDC) Podcasts

    2011-11-17

    Dr. Nancy Strockbine, Chief of the Escherichia and Shigella Reference Unit at CDC, discusses Shigella sonnei infections.  Created: 11/17/2011 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 11/21/2011.

  19. Genetic characterization of Shigella spp. isolated from diarrhoeal and asymptomatic children.

    Science.gov (United States)

    Ghosh, Santanu; Pazhani, Gururaja P; Niyogi, Swapan Kumar; Nataro, James P; Ramamurthy, Thandavarayan

    2014-07-01

    Phenotypic and genetic characteristics of Shigella spp. isolated from diarrhoeal and asymptomatic children aged up to 5 years were analysed in this study. In total, 91 and 17 isolates were identified from diarrhoeal (case) and asymptomatic (control) children, respectively. All the isolates were tested for antimicrobial resistance, the presence of integrons, plasmid-mediated quinolone resistance (PMQR), virulence-associated genes and Shigella pathogenicity island (SH-PAI). The majority of the Shigella spp. from cases (68.1%) and controls (82.3%) were found to be resistant to fluoroquinolones. Integron carriage was detected more in cases (76.9%) than in controls (35.5%). Atypical class 1 integron was detected exclusively in Shigella flexneri from cases but not from the controls. PMQR genes such as aac(6')-Ib-cr and qnrS1 were detected in 82.4 and 14.3% of the isolates from cases and in 53 and 17.6% in controls, respectively. Shigella isolates from cases as well as from controls were positive for the invasive plasmid antigen H-encoding gene ipaH. The other virulence genes such as virF, sat, setA, setB, sen and ial were detected in Shigella isolates in 80.2, 49.4, 27.4, 27.4, 80.2 and 79.1% of cases and in 64.7, 52.9, 17.6, 17.6, 64.7 and 64.7% of controls, respectively. The entire SH-PAI was detected in S. flexneri serotype 2a from cases and controls. In an isolate from a control child, the SH-PAI was truncated. Integrons, PMQR and virulence-encoding genes were detected more frequently in cases than in controls. In diarrhoea endemic areas, asymptomatic carriers may play a crucial role in the transmission of multidrug-resistant Shigella spp. with all the putative virulence genes. © 2014 The Authors.

  20. Development of an Aotus nancymaae Model for Shigella Vaccine Immunogenicity and Efficacy Studies

    Science.gov (United States)

    Gregory, Michael; Lugo-Roman, Luis A.; Galvez Carrillo, Hugo; Tilley, Drake Hamilton; Baldeviano, Christian; Simons, Mark P.; Reynolds, Nathanael D.; Ranallo, Ryan T.; Suvarnapunya, Akamol E.; Venkatesan, Malabi M.; Oaks, Edwin V.

    2014-01-01

    Several animal models exist to evaluate the immunogenicity and protective efficacy of candidate Shigella vaccines. The two most widely used nonprimate models for vaccine development include a murine pulmonary challenge model and a guinea pig keratoconjunctivitis model. Nonhuman primate models exhibit clinical features and gross and microscopic colonic lesions that mimic those induced in human shigellosis. Challenge models for enterotoxigenic Escherichia coli (ETEC) and Campylobacter spp. have been successfully developed with Aotus nancymaae, and the addition of a Shigella-Aotus challenge model would facilitate the testing of combination vaccines. A series of experiments were designed to identify the dose of Shigella flexneri 2a strain 2457T that induces an attack rate of 75% in the Aotus monkey. After primary challenge, the dose required to induce an attack rate of 75% was calculated to be 1 × 1011 CFU. Shigella-specific immune responses were low after primary challenge and subsequently boosted upon rechallenge. However, preexisting immunity derived from the primary challenge was insufficient to protect against the homologous Shigella serotype. A successive study in A. nancymaae evaluated the ability of multiple oral immunizations with live-attenuated Shigella vaccine strain SC602 to protect against challenge. After three oral immunizations, animals were challenged with S. flexneri 2a 2457T. A 70% attack rate was demonstrated in control animals, whereas animals immunized with vaccine strain SC602 were protected from challenge (efficacy of 80%; P = 0.05). The overall study results indicate that the Shigella-Aotus nancymaae challenge model may be a valuable tool for evaluating vaccine efficacy and investigating immune correlates of protection. PMID:24595138

  1. Saccharomyces boulardii interferes with Shigella pathogenesis by postinvasion signaling events

    Science.gov (United States)

    Mumy, Karen L.; Chen, Xinhua; Kelly, Ciarán P.; McCormick, Beth A.

    2011-01-01

    Saccharomyces boulardii is gaining in popularity as a treatment for a variety of diarrheal diseases as well as inflammatory bowel disease. This study was designed to examine the effect of this yeast on infection by Shigella flexneri, a highly infectious and human host-adapted enteric pathogen. We investigated key interactions between the bacteria and host cells in the presence of the yeast in addition to a number of host responses including proinflammatory events and markers. Although the presence of the yeast during infection did not alter the number of bacteria that was able to attach or invade human colon cancer-derived T-84 cells, it did positively impact the tight junction protein zonula occluden-2 and significantly increase the barrier integrity of model epithelia. The yeast also decreased ERK, JNK, and NF-κB activation in response to S. flexneri, events likely responsible for the observed reductions in IL-8 secretion and the transepithelial migration of polymorphonuclear leukocytes across T-84 monolayers. These results, suggesting that the yeast allowed for a dampened inflammatory response, were confirmed in vivo utilizing a highly relevant model of human fetal colonic tissue transplanted into scid mice. Furthermore, a cell-free S. boulardii culture supernatant was also capable of reducing IL-8 secretion by infected T-84 cells. These data suggest that although the use of S. boulardii during infection with S. flexneri may alleviate symptoms associated with the inflammatory response of the host, it would not prevent infection. PMID:18032477

  2. Antimicrobial Resistance of Shigella spp. isolated in the State of Pará, Brazil

    Directory of Open Access Journals (Sweden)

    Flávia Corrêa Bastos

    2011-10-01

    Full Text Available INTRODUCTION: Shigella spp. are Gram-negative, nonsporulating, rod-shaped bacteria that belong to the family Enterobacteriaceae and are responsible for shigellosis or bacillary dysentery, an important cause of worldwide morbidity and mortality. METHODS: We studied the antibiotic resistance profiles of 122 Shigella spp. strains (81 S. flexneri, 41 S. sonnei, 1 S. boydii isolated from patients (female and male from 0 to 80 years of age presenting diarrhea in different districts of the State of Pará, in the North of Brazil. The antibiotic resistance of the strains, isolated from human fecal samples, was determined by the diffusion disk method and by using the VITEK-2 system. RESULTS: The highest resistance rate found was the resistance rate to tetracycline (93.8%, followed by the resistance rate to chloramphenicol (63.9% and to trimethoprim/sulfamethoxazole (63.1%. Resistance to at least three drugs was more common among S. flexneri than S. sonnei (39.5% vs. 10%. Six (4.9% strains were susceptible to all the antibiotics tested. All strains were susceptible to cefotaxime, ceftazidime, ciprofloxacin, nalidixic acid and nitrofurantoin. CONCLUSIONS: High rates of multidrug resistance in Shigella spp. are a serious public health concern in Brazil. It is extremely important to continuously monitor the antimicrobial resistances of Shigella spp. for effective therapy and control measures against shigellosis.

  3. Antimicrobial properties of lactic acid bacteria isolated from traditional yogurt and milk against Shigella strains.

    Science.gov (United States)

    Zare Mirzaei, Elnaze; Lashani, Elahe; Davoodabadi, Abolfazl

    2018-01-01

    Background: Lactic acid bacteria (LAB) are normal flora of the mouth, intestines and the female genital tract. They are also frequently found in meat, vegetables, and dairy products. Most of probiotic bacteria belong to the LAB group. Some probiotic LAB are useful in prevention and treatment of diarrheal diseases. The aim of this study was to investigate the antimicrobial properties of LAB isolated from traditional yogurt and milk against Shigella strains. Materials and methods: Forty LAB strains were isolated from traditional yogurt and milk. The antimicrobial activity of LAB against Shigella strains (eight S. flexneri , four S. sonnei ) was examined using the agar-well diffusion assay. LAB strains with antimicrobial effect against all Shigella strains were identified by 16S rRNA gene sequencing. Results: Six LAB strains inhibited the growth of all 12 Shigella strains. Lb. paracasei Y1-3, Lb. paracasei Y8-1 and Lb. fermentum Y2-2 were isolated from yogurt. Lb. paracasei M18-1, Lb. parelimentarius M4-3 and Lb. plantarum M19-1 were isolated from milk. Conclusion: This study showed that Lactobacillus strains with good inhibitory activity against S. flexneri and S. sonnei could be isolated from traditional yogurt and milk.

  4. Distribution of genes encoding virulence factors and molecular analysis of Shigella spp. isolated from patients with diarrhea in Kerman, Iran.

    Science.gov (United States)

    Hosseini Nave, Hossein; Mansouri, Shahla; Emaneini, Mohammad; Moradi, Mohammad

    2016-03-01

    Shigella is one of the important causes of diarrhea worldwide. Shigella has several virulence factors contributing in colonization and invasion of epithelial cells and eventually death of host cells. The present study was performed in order to investigate the distribution of virulence factors genes in Shigella spp. isolated from patients with acute diarrhea in Kerman, Iran as well as the genetic relationship of these isolates. A total of 56 isolates including 31 S. flexneri, 18 S. sonnei and 7 S. boydii were evaluated by polymerase chain reaction (PCR) for the presence of 11 virulence genes (ipaH, ial, set1A, set1B, sen, virF, invE, sat, sigA, pic and sepA). Then, the clonal relationship of these strains was analyzed by multilocus variable-number tandem repeat analysis (MLVA) method. All isolates were positive for ipaH gene. The other genes include ial, invE and virF were found in 80.4%, 60.7% and 67.9% of the isolates, respectively. Both set1A and set1B were detected in 32.3% of S. flexneri isolates, whereas 66.1% of the isolates belonging to different serogroup carried sen gene. The sat gene was present in all S. flexneri isolates, but not in the S. sonnei and S. boydii isolates. The result showed, 30.4% of isolates were simultaneously positive and the rest of the isolates were negative for sepA and pic genes. The Shigella isolates were divided into 29 MLVA types. This study, for the first time, investigated distribution of 11 virulence genes in Shigella spp. Our results revealed heterogeneity of virulence genes in different Shigella serogroups. Furthermore, the strains belonging to the same species had little diversity. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. BID-dependent release of mitochondrial SMAC dampens XIAP-mediated immunity against Shigella

    Science.gov (United States)

    Andree, Maria; Seeger, Jens M; Schüll, Stephan; Coutelle, Oliver; Wagner-Stippich, Diana; Wiegmann, Katja; Wunderlich, Claudia M; Brinkmann, Kerstin; Broxtermann, Pia; Witt, Axel; Fritsch, Melanie; Martinelli, Paola; Bielig, Harald; Lamkemeyer, Tobias; Rugarli, Elena I; Kaufmann, Thomas; Sterner-Kock, Anja; Wunderlich, F Thomas; Villunger, Andreas; Martins, L Miguel; Krönke, Martin; Kufer, Thomas A; Utermöhlen, Olaf; Kashkar, Hamid

    2014-01-01

    The X-linked inhibitor of apoptosis protein (XIAP) is a potent caspase inhibitor, best known for its anti-apoptotic function in cancer. During apoptosis, XIAP is antagonized by SMAC, which is released from the mitochondria upon caspase-mediated activation of BID. Recent studies suggest that XIAP is involved in immune signaling. Here, we explore XIAP as an important mediator of an immune response against the enteroinvasive bacterium Shigella flexneri, both in vitro and in vivo. Our data demonstrate for the first time that Shigella evades the XIAP-mediated immune response by inducing the BID-dependent release of SMAC from the mitochondria. Unlike apoptotic stimuli, Shigella activates the calpain-dependent cleavage of BID to trigger the release of SMAC, which antagonizes the inflammatory action of XIAP without inducing apoptosis. Our results demonstrate how the cellular death machinery can be subverted by an invasive pathogen to ensure bacterial colonization. PMID:25056906

  6. Shigella vaccine development: prospective animal models and current status.

    Science.gov (United States)

    Kim, Yeon-Jeong; Yeo, Sang-Gu; Park, Jae-Hak; Ko, Hyun-Jeong

    2013-01-01

    Shigella was first discovered in 1897 and is a major causative agent of dysenteric diarrhea. The number of affected patients has decreased globally because of improved sanitary conditions; however, Shigella still causes serious problems in many subjects, including young children and the elderly, especially in developing countries. Although antibiotics may be effective, a vaccine would be the most powerful solution to combat shigellosis because of the emergence of drug-resistant strains. However, the development of a vaccine is hampered by several problems. First, there is no suitable animal model that can replace human-based studies for the investigation of the in vivo mechanisms of Shigella vaccines. Mouse, guinea pig, rat, rabbit, and nonhuman primates could be used as models for shigellosis, but they do not represent human shigellosis and each has its own weaknesses. However, a recent murine model based on peritoneal infection with virulent S. flexneri 2a is promising. Moreover, although the inflammatory responses and mechanisms such as pathogenassociated molecular patterns and danger-associated molecular patterns have been studied, the pathology and immunology of Shigella are still not clearly defined. Despite these obstacles, many vaccine candidates have been developed, including live attenuated, killed whole cells, conjugated, and subunit vaccines. The development of Shigella vaccines also demands considerations of the cost, routes of administration, ease of storage (stability), cross-reactivity, safety, and immunogenicity. The main aim of this review is to provide a detailed introduction to the many promising vaccine candidates and animal models currently available, including the newly developed mouse model.

  7. Identification and antigenic characterization of virulence-associated, plasmid-coded proteins of Shigella spp. and enteroinvasive Escherichia coli.

    OpenAIRE

    Hale, T L; Oaks, E V; Formal, S B

    1985-01-01

    Seven plasmid-coded polypeptides, designated a through g, were identified by two-dimensional nonequilibrium pH gradient electrophoresis of radiolabeled extracts from minicells of virulent Shigella flexneri serotypes 2a and 5 and enteroinvasive Escherichia coli O143. These polypeptides were deemed to be products of 140-megadalton (MDa) virulence-associated plasmids because they were not synthesized in minicells which were not harboring a 140-MDa plasmid or in minicells which were carrying an F...

  8. Prevalence of Stx-producing Shigella species isolated from French Travelers Returning from the Caribbean: An Emerging Pathogen with International Implications

    Science.gov (United States)

    Gray, Miranda D.; Lacher, David W.; Leonard, Susan R.; Abbott, Jason; Zhao, Shaohua; Lampel, Keith A.; Prothery, Estelle; Gouali, Malika; Weill, François-Xavier; Maurelli, Anthony T.

    2015-01-01

    Shiga toxins are potent cytotoxins that inhibit host cell protein synthesis, leading to cell death. Classically, these toxins are associated with intestinal infections due to Shiga toxin-producing Escherichia coli or Shigella dysenteriae serotype 1 and infections with these strains can lead to hemolytic uremic syndrome. Over the past decade there is increasing recognition that Shiga toxin is produced by additional Shigella species. We recently reported the presence and expression of stx genes in Shigella flexneri 2a clinical isolates. The toxin genes were carried by a new stx-encoding bacteriophage and infection with these strains correlated with recent travel to Haiti or the Dominican Republic. In this study we further explored the epidemiological link to this region by utilizing the French National Reference Center for Escherichia coli, Shigella and Salmonella collection to survey the frequency of Stx-producing Shigella species isolated from French travelers returning from the Caribbean. About 21% of the isolates tested were found to encode and produce Stx. These isolates included strains of S. flexneri 2a, S. flexneri Y, and S. dysenteriae 4. All of the travelers whom were infected with Stx-producing Shigella had recently traveled to Haiti, the Dominican Republic, or French Guiana. Furthermore, whole genome sequencing found that the toxin genes were encoded by a prophage that was highly identical to the phage we identified in our previous study. These findings demonstrate that this new stx-encoding prophage is circulating within that geographical area, has spread to other continents, and is capable of spreading to multiple Shigella serogroups. PMID:25980352

  9. Tetracycline and Azithromycin Resistance Investigation on Shigella spp. Isolated from the Stool of Children with Diarrhea in Tehran, Iran

    Directory of Open Access Journals (Sweden)

    Shadi Shahsavan

    2016-10-01

    Full Text Available Background & objectives: Shigella spp. are gram negative bacteria that can cause shigellosis in human. It is important in young children as well as elderly and immunocompromised people. Threatening complications can occur in severe cases with multidrug resistance species. It has been observed that Shigella spp. have become resistant to antibiotics like other bacteria. Investigation of resistance to azithromycin, tetracycline and pattern of resistance are the objectives of this study. Methods: Fifty isolates of Shigella spp. which have been collected from three hospitals in Tehran were studied. Isolates identified and confirmed as Shigella spp. by biochemical, serological and molecular methods (ipaH, wbgz, rfc genes. Antimicrobial susceptibility test was performed for ampicillin, azithromycin, ciprofloxacin, doxycycline, levofloxacin, minocycline, nalidixic acid, norfloxacin, streptomycin, trimethoprim-sulfamethoxazole and tetracycline by disc agar diffusion method. Minimal inhibition concentrations were performed for azithromycin and tetracycline. Results: From a total of 50 Shigella spp. isolates, 16% of them were Shigella flexneri and 84% Shigella sonnei. The majority of isolates were multidrug resistant. The most resistance was seen to doxycycline, streptomycin, trimethoprim-sulfamethoxazole and tetracycline. Resistance to azithromycin was 6%  and all of the isolates were susceptible to norfloxacin and levofloxacin. Nine patterns of resistance were revealed to these isolates. Conclusion: High resistance to tetracycline was observed and resistance to azithromycin as an alternative treatment choice was also considerable.

  10. How Do the Virulence Factors of Shigella Work Together to Cause Disease?

    Science.gov (United States)

    Mattock, Emily; Blocker, Ariel J

    2017-01-01

    Shigella is the major cause of bacillary dysentery world-wide. It is divided into four species, named S. flexneri, S. sonnei, S. dysenteriae , and S. boydii , which are distinct genomically and in their ability to cause disease. Shigellosis, the clinical presentation of Shigella infection, is characterized by watery diarrhea, abdominal cramps, and fever. Shigella 's ability to cause disease has been attributed to virulence factors, which are encoded on chromosomal pathogenicity islands and the virulence plasmid. However, information on these virulence factors is not often brought together to create a detailed picture of infection, and how this translates into shigellosis symptoms. Firstly, Shigella secretes virulence factors that induce severe inflammation and mediate enterotoxic effects on the colon, producing the classic watery diarrhea seen early in infection. Secondly, Shigella injects virulence effectors into epithelial cells via its Type III Secretion System to subvert the host cell structure and function. This allows invasion of epithelial cells, establishing a replicative niche, and causes erratic destruction of the colonic epithelium. Thirdly, Shigella produces effectors to down-regulate inflammation and the innate immune response. This promotes infection and limits the adaptive immune response, causing the host to remain partially susceptible to re-infection. Combinations of these virulence factors may contribute to the different symptoms and infection capabilities of the diverse Shigella species, in addition to distinct transmission patterns. Further investigation of the dominant species causing disease, using whole-genome sequencing and genotyping, will allow comparison and identification of crucial virulence factors and may contribute to the production of a pan- Shigella vaccine.

  11. Molecular evolution of the nicotinic acid requirement within the Shigella/EIEC pathotype.

    Science.gov (United States)

    Di Martino, Maria Letizia; Fioravanti, Rosa; Barbabella, Giada; Prosseda, Gianni; Colonna, Bianca; Casalino, Mariassunta

    2013-12-01

    Nicotinamide adenine dinucleotide (NAD) is a crucial cofactor in several anabolic and catabolic reactions. NAD derives from quinolinic acid (QUIN) which in Escherichia coli is obtained through a pyridine salvage pathway or a de novo synthesis pathway. In the latter case, two enzymes, L-aspartate oxidase (NadB) and quinolinate synthase (NadA), are required for the synthesis of QUIN. In contrast to its E. coli ancestor, Shigella spp., the causative agent of bacillary dissentery, lacks the de novo pathway and strictly requires nicotinic acid for growth (Nic⁻ phenotype). This phenotype depends on the silencing of the nadB and nadA genes and its pathoadaptive nature is suggested by the observation that QUIN attenuates the Shigella invasive process. Shigella shares the pathogenicity mechanism with enteronvasive E. coli (EIEC), a group of pathogenic E. coli. On the basis of this similarity EIEC and Shigella have been grouped into a single E. coli pathotype. However EIEC strains do not constitute a homogeneous group and do not possess the complete set of characters that define Shigella strains. In this work we have analysed thirteen EIEC strains belonging to different serotypes and originating from different geographic areas. We show that, in contrast to Shigella, only some EIEC strains require nicotinic acid for growth in minimal medium. Moreover, by studying the emergence of the Nic⁻ phenotype in all serotypes of S. flexneri, as well as in S. sonnei and S. dysenteriae, we describe which molecular rearrangements occurred and which mutations are responsible for the inactivation of the nadA and nadB genes. Our data confirm that the genome of Shigella is extremely dynamic and support the hypothesis that EIEC might reflect an earlier stage of the pathoadaptation process undergone by Shigella. Copyright © 2013. Published by Elsevier GmbH.

  12. An attenuated Shigella mutant lacking the RNA-binding protein Hfq provides cross-protection against Shigella strains of broad serotype.

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    Jiro Mitobe

    2017-07-01

    Full Text Available Few live attenuated vaccines protect against multiple serotypes of bacterial pathogen because host serotype-specific immune responses are limited to the serotype present in the vaccine strain. Here, immunization with a mutant of Shigella flexneri 2a protected guinea pigs against subsequent infection by S. dysenteriae type 1 and S. sonnei strains. This deletion mutant lacked the RNA-binding protein Hfq leading to increased expression of the type III secretion system via loss of regulation, resulting in attenuation of cell viability through repression of stress response sigma factors. Such increased antigen production and simultaneous attenuation were expected to elicit protective immunity against Shigella strains of heterologous serotypes. Thus, the vaccine potential of this mutant was tested in two guinea pig models of shigellosis. Animals vaccinated in the left eye showed fewer symptoms upon subsequent challenge via the right eye, and even survived subsequent intestinal challenge. In addition, oral vaccination effectively induced production of immunoglobulins without severe side effects, again protecting all animals against subsequent intestinal challenge with S. dysenteriae type 1 or S. sonnei strains. Antibodies against common virulence proteins and the O-antigen of S. flexneri 2a were detected by immunofluorescence microscopy. Reaction of antibodies with various strains, including enteroinvasive Escherichia coli, suggested that common virulence proteins induced protective immunity against a range of serotypes. Therefore, vaccination is expected to cover not only the most prevalent serotypes of S. sonnei and S. flexneri 2a, but also various Shigella strains, including S. dysenteriae type 1, which produces Shiga toxin.

  13. Characterisation of Shigella species isolated from river catchments in the North West province of South Africa

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    Constance Wose Kinge

    2010-10-01

    Full Text Available The occurrence and distribution of Shigella species in water from the five river catchments in the North West province of South Africa were investigated. Shigella is a Gram-negative, non-motile, facultative anaerobic bacillus that causes shigellosis, an important cause of morbidity and mortality in high-risk populations (such as children, the elderly and immuno-compromised individuals that depend on river water. A total of 54 water samples collected in winter (April 2007 to July 2007 and summer (December 2007 to March 2008 were cultured on Salmonella-Shigella agar by the spread-plate method. Suspected Shigella isolates obtained were characterised by primary biochemical (Triple Sugar Iron agar and agglutination and molecular (polymerase chain reactions, PCR tests. Amplification of the invasion plasmid gene (ipaH by PCR was done to confirm the presence of Shigella spp. in water. In total, 214 Shigella boydii, 15 Shigella dysenteriae, 11 Shigella flexneri and 2 Shigella sonnei were confirmed by serotyping in both winter and summer samples. The ipaH gene (606 bp was present in 176 and 49 of the winter and summer isolates, respectively. The presence of Shigella spp. in water was confirmed with over 90% specificity. The need for more effective management of these river catchments and the provision of potable water and sanitation facilities is needed to minimise the occurrence and transmission of water-borne diseases caused by these and other pathogenic bacteria.

  14. Identification of novel substrates of Shigella T3SA through analysis of its virulence plasmid-encoded secretome

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    Pinaud, Laurie; Ferrari, Mariana L.; Friedman, Robin; Jehmlich, Nico; von Bergen, Martin; Phalipon, Armelle; Sansonetti, Philippe J.

    2017-01-01

    Many human Gram-negative bacterial pathogens express a Type Three Secretion Apparatus (T3SA), including among the most notorious Shigella spp., Salmonella enterica, Yersinia enterocolitica and enteropathogenic Escherichia coli (EPEC). These bacteria express on their surface multiple copies of the T3SA that mediate the delivery into host cells of specific protein substrates critical to pathogenesis. Shigella spp. are Gram-negative bacterial pathogens responsible for human bacillary dysentery. The effector function of several Shigella T3SA substrates has largely been studied but their potential cellular targets are far from having been comprehensively delineated. In addition, it is likely that some T3SA substrates have escaped scrutiny as yet. Indeed, sequencing of the virulence plasmid of Shigella flexneri has revealed numerous open reading frames with unknown functions that could encode additional T3SA substrates. Taking advantage of label-free mass spectrometry detection of proteins secreted by a constitutively secreting strain of S. flexneri, we identified five novel substrates of the T3SA. We further confirmed their secretion through the T3SA and translocation into host cells using β-lactamase assays. The coding sequences of two of these novel T3SA substrates (Orf13 and Orf131a) have a guanine-cytosine content comparable to those of T3SA components and effectors. The three other T3SA substrates identified (Orf48, Orf86 and Orf176) have significant homology with antitoxin moieties of type II Toxin-Antitoxin systems usually implicated in the maintenance of low copy plasmids. While Orf13 and Orf131a might constitute new virulence effectors contributing to S. flexneri pathogenicity, potential roles for the translocation into host cells of antitoxins or antitoxin-like proteins during Shigella infection are discussed. PMID:29073283

  15. Identification of novel substrates of Shigella T3SA through analysis of its virulence plasmid-encoded secretome.

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    Laurie Pinaud

    Full Text Available Many human Gram-negative bacterial pathogens express a Type Three Secretion Apparatus (T3SA, including among the most notorious Shigella spp., Salmonella enterica, Yersinia enterocolitica and enteropathogenic Escherichia coli (EPEC. These bacteria express on their surface multiple copies of the T3SA that mediate the delivery into host cells of specific protein substrates critical to pathogenesis. Shigella spp. are Gram-negative bacterial pathogens responsible for human bacillary dysentery. The effector function of several Shigella T3SA substrates has largely been studied but their potential cellular targets are far from having been comprehensively delineated. In addition, it is likely that some T3SA substrates have escaped scrutiny as yet. Indeed, sequencing of the virulence plasmid of Shigella flexneri has revealed numerous open reading frames with unknown functions that could encode additional T3SA substrates. Taking advantage of label-free mass spectrometry detection of proteins secreted by a constitutively secreting strain of S. flexneri, we identified five novel substrates of the T3SA. We further confirmed their secretion through the T3SA and translocation into host cells using β-lactamase assays. The coding sequences of two of these novel T3SA substrates (Orf13 and Orf131a have a guanine-cytosine content comparable to those of T3SA components and effectors. The three other T3SA substrates identified (Orf48, Orf86 and Orf176 have significant homology with antitoxin moieties of type II Toxin-Antitoxin systems usually implicated in the maintenance of low copy plasmids. While Orf13 and Orf131a might constitute new virulence effectors contributing to S. flexneri pathogenicity, potential roles for the translocation into host cells of antitoxins or antitoxin-like proteins during Shigella infection are discussed.

  16. Development of recombinant vaccine candidate molecule against Shigella infection.

    Science.gov (United States)

    Chitradevi, S T S; Kaur, G; Sivaramakrishna, U; Singh, D; Bansal, A

    2016-10-17

    Shigellosis is an acute bacillary diarrheal disease caused by the gram negative bacillus Shigella. The existence of multiple Shigella serotypes and their growing resistance to antibiotics stress the urgent need for the development of vaccine that is protective across all serotypes. Shigella's IpaB antigen is involved in translocon pore formation, promotes bacterial invasion and induces apoptosis in macrophages. S. Typhi GroEL (Hsp 60) is the immunodominant antigen inducing both arms of immunity and has been explored as adjuvant in this study. The present study evaluates the immunogenicity and protective efficacy of recombinant IpaB domain-GroEL fusion protein in mice against lethal Shigella infection. The IpaB domain and GroEL genes were fused using overlap extension PCR and cloned in pRSETA expression vector. Fused gene was expressed in Escherichia coli BL-21 cells and the resulting 90 KDa fusion protein was purified by affinity chromatography. Intranasal (i.n.) immunization of mice with fusion protein increased the IgG and IgA antibody titers as compared to the group immunized with IpaB and GroEL and control PBS immunized group. Also IgG1 and IgG2a antibodies induced in fusion protein immunized mice were higher than co-immunized group. Significant increase in lymphocyte proliferation and cytokine levels (IFN-γ, IL-4 and IL-10), indicates induction of both Th1 and Th2 immune responses in both immunized groups. Immunization with fusion protein protected 90-95% of mice whereas 80-85% survivability was observed in co-immunized group against lethal challenge with S. flexneri, S. boydii and S. sonnei. Passive immunization conferred 60-70% protection in mice against all these Shigella species. Organ burden and histopathology studies also revealed significant decrease in lung infection as compared to the co-immunized group. Since IpaB is the conserved dominant molecule in all Shigella species, this study will lead to an ideal platform for the development of safe

  17. Transfer patterns of integron-associated and antibiotic resistance genes in S. flexneri during different time intervals in Tianjin, China

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    J Wang

    2014-01-01

    Full Text Available Background: Shigella is one of the common genera of pathogens responsible for bacterial diarrhoea in humans. According to World Health Organisation (WHO, 800,000-1,700,000 patients in China were infected with Shigella spp. in 2000, and Shigella flexneri is the most common serotype (86%. Objectives: We investigated the transfer patterns of integron-associated and antibiotic resistance genes in S. flexneri during different time intervals in the city of Tianjin in the People′s Republic of China. Materials and Methods: The integrase-encoding and variable regions of the integrons of the bacterial strains were amplified by polymerase chain reaction (PCR, followed by gene sequencing. Fifty-six S. flexneri strains, 32 of which were stored in our laboratory and the other 24 were isolated from tertiary hospitals in Tianjin during different time intervals, were tested for their sensitivity to 12 antibiotics by using the Kirby-Bauer antibiotic testing method (K-B method. Results and Conclusion: Of the 32 strains of S. flexneri isolated from 1981 to 1983 and stored in our laboratory, class 1 integron was detected in 28 strains (87.50%, while 27 strains (84.37% harboured an aminoglycoside resistance gene, aadA, in the variable region of their integrons. Class 1 integron was identified in 22 (91.67% of the 24 S. flexneri strains isolated from 2009 to 2010, whereas the variable region and 3′-end amplification were not present in any of the strains. Class 2 integron was not found in the 1981-1983 group (group A of strains; although 19 (79.17% of the 24 strains in the 2009-2010 group (group B possessed class 2 integron, and the variable region of the integron harboured dfrA1 + sat1 + aadA1 genes, which, respectively, mediate antibiotic resistance to trimethoprim, streptothricin and streptomycin. Seventeen strains of the total 56 possessed both class 1 and 2 integrons. Strains belonging to group A were highly resistant to tetracycline, chloramphenicol and a

  18. Antimicrobial resistance and PCR-ribotyping of Shigella responsible for foodborne outbreaks occurred in southern Brazil

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    Cheila Minéia Daniel de Paula

    2010-12-01

    Full Text Available Little information about Shigella responsible for foodborne shigellosis is available in Brazil. The present study aimed to investigate the antimicrobial resistance and PCR-ribotyping patterns of Shigella isolates responsible for foodborne outbreaks occurred in Rio Grande do Sul State (RS, Southern Brazil in the period between 2003 and 2007. Shigella strains (n=152 were isolated from foods and fecal samples of victims of shigellosis outbreaks investigated by the Surveillance Service. Identification of the strains at specie level indicated that 71.1% of them were S. flexneri, 21.5% S. sonnei, and 0.7% S. dysenteriae. Ten strains (6.7% were identified only as Shigella spp. An increasing occurrence of S. sonnei was observed after 2004. Most of the strains were resistant to streptomycin (88.6%, followed by ampicillin (84.6%, and sulfamethoxazole/trimethoprim (80.5 %. Resistant strains belonged to 73 patterns, and pattern A (resistance to ampicillin, sulfamethoxazole/trimethoprim, tetracycline, streptomycin, chloramphenicol, and intermediate resistance to kanamycin grouped the largest number of isolates (n=36. PCR-ribotyping identified three banding patterns (SH1, SH2, and SH3. SH1 grouped all S. flexneri and SH2 grouped all S. sonnei. The S. dysenteriae strain belonged to group SH3. According to the results, several Shigella isolates shared the same PCR-rybotyping banding pattern and the same resistance profile, suggesting that closely related strains were responsible for the outbreaks. However, other molecular typing methods need to be applied to confirm the clonal relationship of these isolates.

  19. Distinct Mutations Led to Inactivation of Type 1 Fimbriae Expression in Shigella spp.

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    Bravo, Verónica; Puhar, Andrea; Sansonetti, Philippe; Parsot, Claude; Toro, Cecilia S.

    2015-01-01

    Shigella spp. are responsible for bacillary dysentery in humans. The acquisition or the modification of the virulence plasmid encoding factors promoting entry of bacteria into and dissemination within epithelial cells was a critical step in the evolution of these bacteria from their Escherichia coli ancestor(s). Incorporation of genomic islands (GI) and gene inactivation also shaped interactions between these pathogens and their human host. Sequence analysis of the GI inserted next to the leuX tRNA gene in S. boydii, S. dysenteriae, S. flexneri, S. sonnei and enteroinvasive E. coli (EIEC) suggests that this region initially carried the fec, yjhATS and fim gene clusters. The fim cluster encoding type I fimbriae is systematically inactivated in both reference strains and clinical isolates and distinct mutations are responsible for this inactivation in at least three phylogenetic groups. To investigate consequences of the presence of fimbriae on the outcome of the interaction of Shigella with host cells, we used a S. flexneri strain harboring a plasmid encoding the E. coli fim operon. Production of fimbriae by this recombinant strain increased the ability of bacteria to adhere to and enter into epithelial cells and had no effect on their ability to disseminate from cell to cell. The observations that production of type I fimbriae increases invasion of epithelial cells and that independent mutations abolish fimbriae production in Shigella suggest that these mutations correspond to pathoadaptive events. PMID:25811616

  20. Distinct mutations led to inactivation of type 1 fimbriae expression in Shigella spp.

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    Verónica Bravo

    Full Text Available Shigella spp. are responsible for bacillary dysentery in humans. The acquisition or the modification of the virulence plasmid encoding factors promoting entry of bacteria into and dissemination within epithelial cells was a critical step in the evolution of these bacteria from their Escherichia coli ancestor(s. Incorporation of genomic islands (GI and gene inactivation also shaped interactions between these pathogens and their human host. Sequence analysis of the GI inserted next to the leuX tRNA gene in S. boydii, S. dysenteriae, S. flexneri, S. sonnei and enteroinvasive E. coli (EIEC suggests that this region initially carried the fec, yjhATS and fim gene clusters. The fim cluster encoding type I fimbriae is systematically inactivated in both reference strains and clinical isolates and distinct mutations are responsible for this inactivation in at least three phylogenetic groups. To investigate consequences of the presence of fimbriae on the outcome of the interaction of Shigella with host cells, we used a S. flexneri strain harboring a plasmid encoding the E. coli fim operon. Production of fimbriae by this recombinant strain increased the ability of bacteria to adhere to and enter into epithelial cells and had no effect on their ability to disseminate from cell to cell. The observations that production of type I fimbriae increases invasion of epithelial cells and that independent mutations abolish fimbriae production in Shigella suggest that these mutations correspond to pathoadaptive events.

  1. A novel multiplex PCR for the simultaneous detection of Salmonella enterica and Shigella species.

    Science.gov (United States)

    Radhika, M; Saugata, Majumder; Murali, H S; Batra, H V

    2014-01-01

    Salmonella enterica and Shigella species are commonly associated with food and water borne infections leading to gastrointestinal diseases. The present work was undertaken to develop a sensitive and reliable PCR based detection system for simultaneous detection of Salmonella enterica and Shigella at species level. For this the conserved regions of specific genes namely ipaH1, ipaH, wbgZ, wzy and invA were targeted for detection of Shigella genus, S. flexneri, S. sonnei, S. boydii and Salmonella enterica respectively along with an internal amplification control (IAC). The results showed that twenty Salmonella and eleven Shigella spp., were accurately identified by the assay without showing non-specificity against closely related other Enterobacteriaceae organisms and also against other pathogens. Further evaluation of multiplex PCR was undertaken on 50 natural samples of chicken, eggs and poultry litter and results compared with conventional culture isolation and identification procedure. The multiplex PCR identified the presence of Salmonella and Shigella strains with a short pre-enrichment step of 5 h in peptone water and the same samples were processed by conventional procedures for comparison. Therefore, this reported multiplex PCR can serve as an alternative to the tedious time-consuming procedure of culture and identification in food safety laboratories.

  2. Antimicrobial Resistance of Shigella spp. isolated in the State of Pará, Brazil Resistência Antimicrobiana de Shigella spp. isoladas no Estado do Pará

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    Flávia Corrêa Bastos

    2011-10-01

    Full Text Available INTRODUCTION: Shigella spp. are Gram-negative, nonsporulating, rod-shaped bacteria that belong to the family Enterobacteriaceae and are responsible for shigellosis or bacillary dysentery, an important cause of worldwide morbidity and mortality. METHODS: We studied the antibiotic resistance profiles of 122 Shigella spp. strains (81 S. flexneri, 41 S. sonnei, 1 S. boydii isolated from patients (female and male from 0 to 80 years of age presenting diarrhea in different districts of the State of Pará, in the North of Brazil. The antibiotic resistance of the strains, isolated from human fecal samples, was determined by the diffusion disk method and by using the VITEK-2 system. RESULTS: The highest resistance rate found was the resistance rate to tetracycline (93.8%, followed by the resistance rate to chloramphenicol (63.9% and to trimethoprim/sulfamethoxazole (63.1%. Resistance to at least three drugs was more common among S. flexneri than S. sonnei (39.5% vs. 10%. Six (4.9% strains were susceptible to all the antibiotics tested. All strains were susceptible to cefotaxime, ceftazidime, ciprofloxacin, nalidixic acid and nitrofurantoin. CONCLUSIONS: High rates of multidrug resistance in Shigella spp. are a serious public health concern in Brazil. It is extremely important to continuously monitor the antimicrobial resistances of Shigella spp. for effective therapy and control measures against shigellosis.INTRODUÇÃO: Shigella spp. são bactérias Gram-negativas, não esporuladas, em forma de bastonete, pertencentes a família Enterobacteriaceae responsáveis pela shigelose ou disenteria bacilar, uma importante causa de mortalidade e morbidade mundial. MÉTODOS: Foi estudado o perfil de resistência a antimicrobianos de 122 amostras de Shigella spp. (81 S. flexneri, 41 sonnei, 1 S. boydii isoladas de pacientes (sexo feminino e masculino com faixa etária de 0 a 80 anos com distúrbios gastrointestinais em diferentes municípios no Estado do Par

  3. An integrated approach for finding overlooked genes in Shigella.

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    Junping Peng

    Full Text Available BACKGROUND: The completion of numerous genome sequences introduced an era of whole-genome study. However, many genes are missed during genome annotation, including small RNAs (sRNAs and small open reading frames (sORFs. In order to improve genome annotation, we aimed to identify novel sRNAs and sORFs in Shigella, the principal etiologic agents of bacillary dysentery. METHODOLOGY/PRINCIPAL FINDINGS: We identified 64 sRNAs in Shigella, which were experimentally validated in other bacteria based on sequence conservation. We employed computer-based and tiling array-based methods to search for sRNAs, followed by RT-PCR and northern blots, to identify nine sRNAs in Shigella flexneri strain 301 (Sf301 and 256 regions containing possible sRNA genes. We found 29 candidate sORFs using bioinformatic prediction, array hybridization and RT-PCR verification. We experimentally validated 557 (57.9% DOOR operon predictions in the chromosomes of Sf301 and 46 (76.7% in virulence plasmid.We found 40 additional co-expressed gene pairs that were not predicted by DOOR. CONCLUSIONS/SIGNIFICANCE: We provide an updated and comprehensive annotation of the Shigella genome. Our study increased the expected numbers of sORFs and sRNAs, which will impact on future functional genomics and proteomics studies. Our method can be used for large scale reannotation of sRNAs and sORFs in any microbe with a known genome sequence.

  4. Virulence factors and mechanisms of antimicrobial resistance in Shigella strains from periurban areas of Lima (Peru).

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    Lluque, Angela; Mosquito, Susan; Gomes, Cláudia; Riveros, Maribel; Durand, David; Tilley, Drake H; Bernal, María; Prada, Ana; Ochoa, Theresa J; Ruiz, Joaquim

    2015-01-01

    The study was aimed to describe the serotype, mechanisms of antimicrobial resistance, and virulence determinants in Shigella spp. isolated from Peruvian children. Eighty three Shigella spp. were serogrouped and serotyped being established the antibiotic susceptibility. The presence of 12 virulence factors (VF) and integrase 1 and 2, along with commonly found antibiotic resistance genes was established by PCR. S. flexneri was the most relevant serogroup (55 isolates, 66%), with serotype 2a most frequently detected (27 of 55, 49%), followed by S. boydii and S. sonnei at 12 isolates each (14%) and S. dysenteriae (four isolates, 5%). Fifty isolates (60%) were multi-drug resistant (MDR) including 100% of S. sonnei and 64% of S. flexneri. Resistance levels were high to trimethoprim-sulfamethoxazole (86%), tetracycline (74%), ampicillin (67%), and chloramphenicol (65%). Six isolates showed decreased azithromycin susceptibility. No isolate was resistant to nalidixic acid, ciprofloxacin, nitrofurantoin, or ceftriaxone. The most frequent resistance genes were sul2 (95%), tet(B) (92%), cat (80%), dfrA1 (47%), blaOXA-1like (40%), with intl1 and intl2 detected in 51 and 52% of the isolates, respectively. Thirty-one different VF profiles were observed, being the ipaH (100%), sen (77%), virA and icsA (75%) genes the most frequently found. Differences in the prevalence of VF were observed between species with S. flexneri isolates, particularly serotype 2a, possessing high numbers of VF. In conclusion, this study highlights the high heterogeneity of Shigella VF and resistance genes, and prevalence of MDR organisms within this geographic region. Copyright © 2015 Elsevier GmbH. All rights reserved.

  5. Epidemic and virulence characteristic of Shigella spp. with extended-spectrum cephalosporin resistance in Xiaoshan District, Hangzhou, China

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    2014-01-01

    Background Shigellae have become increasingly resistant to the extended-spectrum cephalosporin (ESC) worldwide and pose a great challenge to anti-infection treatment options. The purpose of this study was to determine the resistance, cephalosporin resistance mechanisms, virulence characteristic and genotype of ESC-resistant Shigella. Methods From 2008 to 2012, Shigella isolates collected from diarrhea patients were detected for antibiotics sensitivity by disk diffusion, cephalosporin resistance determinants and virulence genes using polymerase chain reaction (PCR) and genotyping through enterobacterial repetitive intergenic consensus sequence PCR (ERIC-PCR). Results A total of 356 Shigella isolates were gathered, and 198 (55.6%, 58 S. flexneri and 140 S. sonnei) were resistant to ESC. All ESC-resistant isolates were susceptible to imipenem, and only 0.5% isolate was resistant to piperacillin/tazobactam. ESC-resistant S. flexneri showed high degrees of resistance to ampicillin (100%), ampicillin/sulbactam (96.6%), piperacillin (100%), trimethoprim/sulfamethoxazole (74.1%), ciprofloxacin (74.1%), levofloxacin (53.4%), ceftazidime (58.6%) and cefepime (58.6%). ESC-resistant S. sonnei exhibited high resistance rates to ampicillin (100%), piperacillin (100%) and trimethoprim/sulfamethoxazole (96.4%). Cephalosporin resistance genes were confirmed in 184 ESC-resistant isolates. blaCTX-M types (91.8%, mainly blaCTX-M-14, blaCTX-M-15 and blaCTX-M-57) were most prevalent, followed by blaOXA-30 (26.3%). Over 99.0% ESC-resistant isolates harbored virulence genes ial, ipaH, virA and sen. However, set1 were more prevalent in ESC-resistant S. flexneri isolates than in S. sonnei isolates. ERIC-PCR results showed that 2 and 3 main genotypes were detected in ESC-resistant S. flexneri and S. sonnei, respectively. Conclusion Our findings indicated that a high prevalence of ESC-resistant Shigella mediated mainly by blaCTX-M with stronger resistance and virulence, and the existence

  6. Characterization of a novel fusion protein from IpaB and IpaD of Shigella spp. and its potential as a pan-Shigella vaccine.

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    Martinez-Becerra, Francisco J; Chen, Xiaotong; Dickenson, Nicholas E; Choudhari, Shyamal P; Harrison, Kelly; Clements, John D; Picking, William D; Van De Verg, Lillian L; Walker, Richard I; Picking, Wendy L

    2013-12-01

    Shigellosis is an important disease in the developing world, where about 90 million people become infected with Shigella spp. each year. We previously demonstrated that the type three secretion apparatus (T3SA) proteins IpaB and IpaD are protective antigens in the mouse lethal pulmonary model. In order to simplify vaccine formulation and process development, we have evaluated a vaccine design that incorporates both of these previously tested Shigella antigens into a single polypeptide chain. To determine if this fusion protein (DB fusion) retains the antigenic and protective capacities of IpaB and IpaD, we immunized mice with the DB fusion and compared the immune response to that elicited by the IpaB/IpaD combination vaccine. Purification of the DB fusion required coexpression with IpgC, the IpaB chaperone, and after purification it maintained the highly α-helical characteristics of IpaB and IpaD. The DB fusion also induced comparable immune responses and retained the ability to protect mice against Shigella flexneri and S. sonnei in the lethal pulmonary challenge. It also offered limited protection against S. dysenteriae challenge. Our results show the feasibility of generating a protective Shigella vaccine comprised of the DB fusion.

  7. Characterization of a Novel Fusion Protein from IpaB and IpaD of Shigella spp. and Its Potential as a Pan-Shigella Vaccine

    Science.gov (United States)

    Martinez-Becerra, Francisco J.; Chen, Xiaotong; Dickenson, Nicholas E.; Choudhari, Shyamal P.; Harrison, Kelly; Clements, John D.; Picking, William D.; Van De Verg, Lillian L.; Walker, Richard I.

    2013-01-01

    Shigellosis is an important disease in the developing world, where about 90 million people become infected with Shigella spp. each year. We previously demonstrated that the type three secretion apparatus (T3SA) proteins IpaB and IpaD are protective antigens in the mouse lethal pulmonary model. In order to simplify vaccine formulation and process development, we have evaluated a vaccine design that incorporates both of these previously tested Shigella antigens into a single polypeptide chain. To determine if this fusion protein (DB fusion) retains the antigenic and protective capacities of IpaB and IpaD, we immunized mice with the DB fusion and compared the immune response to that elicited by the IpaB/IpaD combination vaccine. Purification of the DB fusion required coexpression with IpgC, the IpaB chaperone, and after purification it maintained the highly α-helical characteristics of IpaB and IpaD. The DB fusion also induced comparable immune responses and retained the ability to protect mice against Shigella flexneri and S. sonnei in the lethal pulmonary challenge. It also offered limited protection against S. dysenteriae challenge. Our results show the feasibility of generating a protective Shigella vaccine comprised of the DB fusion. PMID:24060976

  8. An O antigen capsule modulates bacterial pathogenesis in Shigella sonnei.

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    Caboni, Mariaelena; Pédron, Thierry; Rossi, Omar; Goulding, David; Pickard, Derek; Citiulo, Francesco; MacLennan, Calman A; Dougan, Gordon; Thomson, Nicholas R; Saul, Allan; Sansonetti, Philippe J; Gerke, Christiane

    2015-03-01

    Shigella is the leading cause for dysentery worldwide. Together with several virulence factors employed for invasion, the presence and length of the O antigen (OAg) of the lipopolysaccharide (LPS) plays a key role in pathogenesis. S. flexneri 2a has a bimodal OAg chain length distribution regulated in a growth-dependent manner, whereas S. sonnei LPS comprises a monomodal OAg. Here we reveal that S. sonnei, but not S. flexneri 2a, possesses a high molecular weight, immunogenic group 4 capsule, characterized by structural similarity to LPS OAg. We found that a galU mutant of S. sonnei, that is unable to produce a complete LPS with OAg attached, can still assemble OAg material on the cell surface, but a galU mutant of S. flexneri 2a cannot. High molecular weight material not linked to the LPS was purified from S. sonnei and confirmed by NMR to contain the specific sugars of the S. sonnei OAg. Deletion of genes homologous to the group 4 capsule synthesis cluster, previously described in Escherichia coli, abolished the generation of the high molecular weight OAg material. This OAg capsule strongly affects the virulence of S. sonnei. Uncapsulated knockout bacteria were highly invasive in vitro and strongly inflammatory in the rabbit intestine. But, the lack of capsule reduced the ability of S. sonnei to resist complement-mediated killing and to spread from the gut to peripheral organs. In contrast, overexpression of the capsule decreased invasiveness in vitro and inflammation in vivo compared to the wild type. In conclusion, the data indicate that in S. sonnei expression of the capsule modulates bacterial pathogenesis resulting in balanced capabilities to invade and persist in the host environment.

  9. An O antigen capsule modulates bacterial pathogenesis in Shigella sonnei.

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    Mariaelena Caboni

    2015-03-01

    Full Text Available Shigella is the leading cause for dysentery worldwide. Together with several virulence factors employed for invasion, the presence and length of the O antigen (OAg of the lipopolysaccharide (LPS plays a key role in pathogenesis. S. flexneri 2a has a bimodal OAg chain length distribution regulated in a growth-dependent manner, whereas S. sonnei LPS comprises a monomodal OAg. Here we reveal that S. sonnei, but not S. flexneri 2a, possesses a high molecular weight, immunogenic group 4 capsule, characterized by structural similarity to LPS OAg. We found that a galU mutant of S. sonnei, that is unable to produce a complete LPS with OAg attached, can still assemble OAg material on the cell surface, but a galU mutant of S. flexneri 2a cannot. High molecular weight material not linked to the LPS was purified from S. sonnei and confirmed by NMR to contain the specific sugars of the S. sonnei OAg. Deletion of genes homologous to the group 4 capsule synthesis cluster, previously described in Escherichia coli, abolished the generation of the high molecular weight OAg material. This OAg capsule strongly affects the virulence of S. sonnei. Uncapsulated knockout bacteria were highly invasive in vitro and strongly inflammatory in the rabbit intestine. But, the lack of capsule reduced the ability of S. sonnei to resist complement-mediated killing and to spread from the gut to peripheral organs. In contrast, overexpression of the capsule decreased invasiveness in vitro and inflammation in vivo compared to the wild type. In conclusion, the data indicate that in S. sonnei expression of the capsule modulates bacterial pathogenesis resulting in balanced capabilities to invade and persist in the host environment.

  10. Manipulation of host membranes by the bacterial pathogens Listeria, Francisella, Shigella and Yersinia.

    Science.gov (United States)

    Pizarro-Cerdá, Javier; Charbit, Alain; Enninga, Jost; Lafont, Frank; Cossart, Pascale

    2016-12-01

    Bacterial pathogens display an impressive arsenal of molecular mechanisms that allow survival in diverse host niches. Subversion of plasma membrane and cytoskeletal functions are common themes associated to infection by both extracellular and intracellular pathogens. Moreover, intracellular pathogens modify the structure/stability of their membrane-bound compartments and escape degradation from phagocytic or autophagic pathways. Here, we review the manipulation of host membranes by Listeria monocytogenes, Francisella tularensis, Shigella flexneri and Yersinia spp. These four bacterial model pathogens exemplify generalized strategies as well as specific features observed during bacterial infection processes. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  11. Pathogenicity of Shigella in chickens.

    Science.gov (United States)

    Shi, Run; Yang, Xia; Chen, Lu; Chang, Hong-tao; Liu, Hong-ying; Zhao, Jun; Wang, Xin-wei; Wang, Chuan-qing

    2014-01-01

    Shigellosis in chickens was first reported in 2004. This study aimed to determine the pathogenicity of Shigella in chickens and the possibility of cross-infection between humans and chickens. The pathogenicity of Shigella in chickens was examined via infection of three-day-old SPF chickens with Shigella strain ZD02 isolated from a human patient. The virulence and invasiveness were examined by infection of the chicken intestines and primary chicken intestinal epithelial cells. The results showed Shigella can cause death via intraperitoneal injection in SPF chickens, but only induce depression via crop injection. Immunohistochemistry and transmission electron microscopy revealed the Shigella can invade the intestinal epithelia. Immunohistochemistry of the primary chicken intestinal epithelial cells infected with Shigella showed the bacteria were internalized into the epithelial cells. Electron microscopy also confirmed that Shigella invaded primary chicken intestinal epithelia and was encapsulated by phagosome-like membranes. Our data demonstrate that Shigella can invade primary chicken intestinal epithelial cells in vitro and chicken intestinal mucosa in vivo, resulting in pathogenicity and even death. The findings suggest Shigella isolated from human or chicken share similar pathogenicity as well as the possibility of human-poultry cross-infection, which is of public health significance.

  12. Macropinosomes are Key Players in Early Shigella Invasion and Vacuolar Escape in Epithelial Cells.

    Directory of Open Access Journals (Sweden)

    Allon Weiner

    2016-05-01

    Full Text Available Intracellular pathogens include all viruses, many bacteria and parasites capable of invading and surviving within host cells. Key to survival is the subversion of host cell pathways by the pathogen for the purpose of propagation and evading the immune system. The intracellular bacterium Shigella flexneri, the causative agent of bacillary dysentery, invades host cells in a vacuole that is subsequently ruptured to allow growth of the pathogen within the host cytoplasm. S. flexneri invasion has been classically described as a macropinocytosis-like process, however the underlying details and the role of macropinosomes in the intracellular bacterial lifestyle have remained elusive. We applied dynamic imaging and advanced large volume correlative light electron microscopy (CLEM to study the highly transient events of S. flexneri's early invasion into host epithelial cells and elucidate some of its fundamental features. First, we demonstrate a clear distinction between two compartments formed during the first step of invasion: the bacterial containing vacuole and surrounding macropinosomes, often considered identical. Next, we report a functional link between macropinosomes and the process of vacuolar rupture, demonstrating that rupture timing is dependent on the availability of macropinosomes as well as the activity of the small GTPase Rab11 recruited directly to macropinosomes. We go on to reveal that the bacterial containing vacuole and macropinosomes come into direct contact at the onset of vacuolar rupture. Finally, we demonstrate that S. flexneri does not subvert pre-existing host endocytic vesicles during the invasion steps leading to vacuolar rupture, and propose that macropinosomes are the major compartment involved in these events. These results provide the basis for a new model of the early steps of S. flexneri epithelial cell invasion, establishing a different view of the enigmatic process of cytoplasmic access by invasive bacterial

  13. Antimicrobial susceptibility pattern of Shigella spp. isolated from children under 5 years of age attending tertiary care hospitals, Nepal along with first finding of ESBL-production.

    Science.gov (United States)

    Dhital, Subhash; Sherchand, Jeevan Bahadur; Pokharel, Bharat Mani; Parajuli, Keshab; Mishra, Shyam Kumar; Sharma, Sangita; Kattel, Hari Prasad; Khadka, Sundar; Khatiwada, Sulochana; Rijal, Basista

    2017-06-05

    Shigella is an important cause of bacterial gastroenteritis in resource-poor countries. The treatment of shigellosis mostly requires antibiotics. However, the increase of multidrug resistance along with emergence of extended-spectrum β-lactamase and ciprofloxacin resistance among Shigella spp. has challenged the situation. This study was conducted to determine the distribution of species and antibiotic susceptibility pattern of Shigella species isolated from stool specimen among children less than 5 years of age in Nepal. Out of total 717 stool samples collected, 15 cases of Shigella spp. was isolated which includes 12 S. flexneri and 3 S. sonnei. Multidrug resistance was found among 13(86%) of the isolates. One of the isolates of S. flexneri was found to be ESBL-producer with MIC >256 mg/L for cefixime. The high occurrence of multidrug resistance among Shigella spp. along with a case of ESBL-production for the first time in Nepal alarms the concerns about dissemination of the resistant isolates. So, systemic monitoring of the antimicrobial susceptibility pattern of Shigella spp. is becoming crucial to guide therapy.

  14. Resistencia a antibióticos y epidemiología molecular de Shigella spp. en el nordeste argentino Antibiotic resistance and molecular epidemiology of Shigella spp. in northeastern Argentina

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    Luis A. Merino

    2004-04-01

    Full Text Available OBJETIVOS: Evaluar la resistencia a antibióticos de cepas de Shigella spp. aisladas de muestras de heces en el nordeste argentino y caracterizarlas desde el punto de vista de su epidemiología molecular. MÉTODOS: Se estudiaron 132 aislamientos de Shigella spp. obtenidos de las heces de igual número de pacientes con diarrea que asistieron a diferentes laboratorios privados y estatales de las provincias del Chaco y Corrientes, Argentina, durante el período de 1998 a 2002. Cada cepa se caracterizó según su serotipo, su resistencia a 13 antibióticos individuales o combinados y su sensibilidad a las piocinas. A 52 cepas seleccionadas en función de sus perfiles de susceptibilidad antimicrobiana se les determinaron la dotación plasmídica mediante lisis alcalina y las secuencias repetitivas palindrómicas extragénicas mediante la amplificación de segmentos repetitivos de ADN con la reacción en cadena de la polimerasa (REP-RCP. Se aplicó la prueba de ji al cuadrado para comparar proporciones. El nivel de significación estadística fue de 0,05. RESULTADOS: Shigella flexneri fue la especie más frecuente (78%, seguida de S. sonnei (22%. En general, la resistencia de S. flexneri a los antibióticos estudiados fue mayor que la de S. sonnei y esta diferencia fue estadísticamente significativa (P OBJECTIVES: To evaluate the antibiotic resistance of strains of Shigella spp. isolated from feces samples from northeastern Argentina and to characterize the strains in terms of their molecular epidemiology. METHODS: We studied 132 isolates of Shigella spp. obtained from feces samples from 132 patients with diarrhea who were seen at various private and public laboratories in the Argentine provinces of Chaco and Corrientes during the period of 1998 to 2002. Each strain was characterized according to its serotype, its resistance to 13 individual or combination antibiotics, and its sensitivity to pyocins. With 52 strains selected in relation to their

  15. Utilidad del modelo animal ratón-pulmón para evaluar la virulencia de posibles cepas vacunales de Shigella spp

    Directory of Open Access Journals (Sweden)

    Olga M. Martínez

    2008-04-01

    Full Text Available Shigella flexneri y Shigella sonnei, como cualquier otra especie del género Shigella, se sitúan entre los principales agentes etiológicos de las enfermedades diarreicas agudas, sobre todo aquellas que ocurren en los países en vías de desarrollo, aunque por la baja dosis infectante de este enteropatógeno no se excluyen los países desarrollados. Esta situación conlleva a la elaboración de vacunas para prevenir esta enfermedad y la necesidad de un modelo animal que pruebe la eficacia protectora e inmunogénica de posibles candidatos vacunales contra la shigellosis, situación que ha motivado numerosos estudios por la dificultad de demostrar la enteropatía intestinal en los monos y humanos. Lo anteriormente expuesto, más la capacidad de Shigella spp para mostrar resistencia a los antimicrobianos, motivó la realización de este trabajo. En el mismo se constató la utilidad del modelo animal ratón-pulmón para evaluar la virulencia de candidatos vacunales a partir de este microorganismo. Se utilizó la técnica de inoculación intranasal con una concentración entre 107 y 109 UFC de cepas de Shigella flexneri y Shigella sonnei. Por todos los resultados obtenidos con el modelo animal ratón-pulmón se concluyó que este modelo puede ser eficiente para los estudios preclínicos de cualquier candidato vacunal a partir de Shigella spp.

  16. Investigating The Anti-apoptotic Effects of Shigella Flexneri Infection In Epithelial Cells

    Science.gov (United States)

    2009-08-13

    Infect. Immun. 72:6012-6022. 103. Suzuki, T., L. Franchi , C. Toma, H. Ashida, M. Ogawa, Y. Yoshikawa, H. Mimuro, N. Inohara, C. Sasakawa, and G... rule out the 106 possibility that a bacterial T3SS effector protein expressed intracellularly also contributes to the induction of JUN...of the point-counting stereological method (79) using an intraocular reticle of 27-mm diameter, covering 3578 μm 2 (Kr409, Klarman Rulings ) (68

  17. Structure of Spa15, a type III secretion chaperone from Shigella flexneri with broad specificity

    NARCIS (Netherlands)

    Eerde, André van; Hamiaux, Cyril; Pérez, Javier; Parsot, Claude; Dijkstra, Bauke W.

    2004-01-01

    Type III secretion (TTS) systems are used by many Gram-negative pathogens to inject virulence proteins into the cells of their hosts. Several of these virulence effectors require TTS chaperones that maintain them in a secretion-competent state. Whereas most chaperones bind only one effector, Spa15

  18. IpaD is localized at the tip of the Shigella flexneri type III secretion apparatus

    NARCIS (Netherlands)

    Sani, Musa; Botteaux, Anne; Parsot, Claude; Sansonetti, Philippe; Boekema, Egbert J.; Allaoui, Abdelmounaaïm

    2007-01-01

    Type III secretion (T3S) systems are used by numerous Gram-negative pathogenic bacteria to inject virulence proteins into animal and plant host cells. The core of the T3S apparatus, known as the needle complex, is composed of a basal body transversing both bacterial membranes and a needle protruding

  19. Shigella flexneri infection in a newly acquired rhesus macaque (Macaca mulatta)

    OpenAIRE

    Lee, Jae-Il; Kim, Sang-Joon; Park, Chung-Gyu

    2011-01-01

    A 3.4 year-old rhesus macaque weighing 4.5 kg, was suffering from anorexia, acute mucous and bloody diarrhea. On physical examination, the monkey showed a loss of activity, hunched posture, abdominal pain, dehydration, mild gingivitis and unclean anus with discharge. Whole blood was collected for the examination of electrolytes, hematology and serum chemistry; fresh stool was also collected for bacterial culture. Blood profiles showed leukocytosis (14.5 K/?L) and neutrophilia (11.0 K/?L) on c...

  20. Relationship between drug resistance and the clustered, regularly interspaced, short, palindromic repeat-associated protein genes cas1 and cas2 in Shigella from giant panda dung.

    Science.gov (United States)

    Ren, Lu; Deng, Lin-Hua; Zhang, Ri-Peng; Wang, Cheng-Dong; Li, De-Sheng; Xi, Li-Xin; Chen, Zhen-Rong; Yang, Rui; Huang, Jie; Zeng, Yang-Ru; Wu, Hong-Lin; Cao, San-Jie; Wu, Rui; Huang, Yong; Yan, Qi-Gui

    2017-02-01

    To detect drug resistance in Shigella obtained from the dung of the giant panda, explore the factors leading to drug resistance in Shigella, understand the characteristics of clustered, regularly interspaced, short, palindromic repeats (CRISPR), and assess the relationship between CRISPR and drug resistance. We collected fresh feces from 27 healthy giant pandas in the Giant Panda Conservation base (Wolong, China). We identified the strains of Shigella in the samples by using nucleotide sequence analysis. Further, the Kirby-Bauer paper method was used to determine drug sensitivity of the Shigella strains. CRISPR-associated protein genes cas1 and cas2 in Shigella were detected by polymerase chain reaction (PCR), and the PCR products were sequenced and compared. We isolated and identified 17 strains of Shigella from 27 samples, including 14 strains of Shigella flexneri, 2 strains of Shigella sonnei, and 1 strain of Shigella dysenteriae. Further, drug resistance to cefazolin, imipenem, and amoxicillin-clavulanic acid was identified as a serious problem, as multidrug-resistant strains were detected. Further, cas1 and cas2 showed different degrees of point mutations. The CRISPR system widely exists in Shigella and shares homology with that in Escherichia coli. The cas1 and cas 2 mutations contribute to the different levels of resistance. Point mutations at sites 3176455, 3176590, and 3176465 in cas1 (a); sites 3176989, 3176992, and 3176995 in cas1 (b); sites 3176156 and 3176236 in cas2 may affect the resistance of bacteria, cause emergence of multidrug resistance, and increase the types of drug resistance.

  1. Salmonella, Shigella, and Yersinia

    Science.gov (United States)

    Dekker, John; Frank, Karen

    2015-01-01

    Synopsis Salmonella, Shigella, and Yersinia cause a well-characterized spectrum of disease in humans, ranging from asymptomatic carriage to hemorrhagic colitis and fatal typhoidal fever. These pathogens are responsible for millions of cases of food-borne illness in the U.S. each year, with substantial costs measured in hospitalizations and lost productivity. In the developing world, illness caused by these pathogens is not only more prevalent, but is also associated with a greater case-fatality rate. Classical methods for identification rely on selective media and serology, but newer methods based on mass spectrometry and PCR show great promise for routine clinical testing. PMID:26004640

  2. Construction of a trivalent candidate vaccine against Shigella species with DNA recombination

    Institute of Scientific and Technical Information of China (English)

    王恒樑; 冯尔玲; 林云; 廖翔; 金明; 黄留玉; 苏国富; 黄翠芬

    2002-01-01

    In this work asd gene of Shigella flexneri 2a strain T32 was replaced by Vibrio cholerae toxin B subunit (ctxB) gene with DNA recombination in vivo and in vitro. The resulting derivative of T32, designed as FWL01, could stably express CtxB, but its growth in LB medium depended on the presence of diaminopimelic acid (DAP). Then form I plasmid of Shigella sonnei strain S7 was labeled with strain T32 asd gene and mobilized into FWL01. Thus a trivalent candidate oral vaccine strain, designed as FSW01, was constructed. In this candidate strain, a balanced-lethal system was constituted between the host strain and the form I plasmid expressing S. sonnei O antigen. Therefore the candidate strain can express stably not only its own O antigen but also CtxB and O antigen of S. sonnei in the absence of any antibiotic. Experiments showed that FSW01 did not invade HeLa cells or cause keratoconjunctivitis in guinea pigs. However, rabbits immunized FSW01 can elicit significant immune responses. In mice and rhesus monkey models, vaccinated animals were protected against the challenges of wild S. flexneri 2a strain 2457T and S. sonnei strain S9.

  3. Multicenter evaluation of molecular and culture-dependent diagnostics for Shigella species and Entero-invasive Escherichia coli in the Netherlands.

    Science.gov (United States)

    van den Beld, Maaike J C; Friedrich, Alexander W; van Zanten, Evert; Reubsaet, Frans A G; Kooistra-Smid, Mirjam A M D; Rossen, John W A

    2016-12-01

    An inter-laboratory collaborative trial for the evaluation of diagnostics for detection and identification of Shigella species and Entero-invasive Escherichia coli (EIEC) was performed. Sixteen Medical Microbiological Laboratories (MMLs) participated. MMLs were interviewed about their diagnostic methods and a sample panel, consisting of DNA-extracts and spiked stool samples with different concentrations of Shigella flexneri, was provided to each MML. The results of the trial showed an enormous variety in culture-dependent and molecular diagnostic techniques currently used among MMLs. Despite the various molecular procedures, 15 out of 16 MMLs were able to detect Shigella species or EIEC in all the samples provided, showing that the diversity of methods has no effect on the qualitative detection of Shigella flexneri. In contrast to semi quantitative analysis, the minimum and maximum values per sample differed by approximately five threshold cycles (Ct-value) between the MMLs included in the study. This indicates that defining a uniform Ct-value cut-off for notification to health authorities is not advisable. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Epidemiological trends and patterns of antimicrobial resistance of Shigella spp. isolated from stool cultures in two different populations in Southern Israel.

    Science.gov (United States)

    Peleg, Itai; Givon-Lavi, Noga; Leibovitz, Eugene; Broides, Arnon

    2014-03-01

    Southern Israel is inhabited by Bedouins, living in conditions similar to developing countries and Jews, living in conditions similar to developed countries. We determined the epidemiology of Shigella spp. in these populations. We retrospectively reviewed Shigella spp. stool isolations between 2005-2009. Overall, 3295 isolates were analyzed. S. sonnei was isolated in 2057/3295 (62.4%) and S. flexneri in 1058 (32.1%). S. sonnei was isolated in 1567/1707 (91.8%) from Jewish patients and S. flexneri in 931/1542 (60.4%) from Bedouin patients. Ampicillin resistance increased linearly from 217/373 (58.2%) in 2005 to 186/256 (72.7%) in 2009, (P Shigella spp. to ampicilin and trimethoprim-sulfamethoxazole were found in Jewish patients: 1527/1706 (89.5%) versus 977/1542 (63.4%) (P Shigella spp. infections can differ in populations residing in the same geographical area. Copyright © 2014 Elsevier Inc. All rights reserved.

  5. Prevalence and antimicrobial susceptibility of Salmonella and Shigella spp. among children with gastroenteritis in an Iranian referral hospital.

    Science.gov (United States)

    Mahmoudi, Shima; Pourakbari, Babak; Moradzadeh, Mina; Eshaghi, Hamid; Ramezani, Amitis; Haghi Ashtiani, Mohammad Taghi; Keshavarz Valian, Sepideh; Mamishi, Setareh

    2017-08-01

    Gastroenteritis is one of the leading cause of illnesses through the world, especially in developing countries.Salmonella and Shigella infections are considered as the main public health problems in children. The aim of this study was to detect the prevalence and antimicrobial susceptibility of Salmonella and Shigella spp. among children with gastroenteritis in an Iranian referral hospital. During April 2013 to April 2014, all medical records of children with gastroenteritis admitted to a pediatric medical center were evaluated. Positive stool cultures of children were evaluated and frequency of Salmonella and Shigella spp. and their antimicrobial susceptibility were detected. In this study, 676 patients with the mean age of 24.94 months were enrolled. Eighty-eight (42%) Salmonella spp., 85 (40%) Shigella spp., 33 (16%) E. coli and 5(2%) candida albicans were isolated from 211 positive stool cultures. Among 85 Shigella spp. isolates, S. sonnei, S. flexneri and other Shigella spp. were isolated from 39 (46%) isolates, 36(42%) and 10(12%), respectively. Among 88 isolated Salmonella spp., 36 (41%) isolates were Salmonella Serogroup D, 26 (30%) were Salmonella Serogroup B, 20 (23%) isolates were Salmonella Serogroup C and 6 (7%) were other Salmonella spp. isolates. Thirty-eight percent of Salmonella serogroup B were resistant to nalidixic acid, while higher frequency of nalidixic acid resistant was found in Salmonella serogroup C and Salmonella serogroup D. The higher frequency of ampicillin resistant was found in Shigella spp. than Salmonella spp. High frequency of cefotaxime resistant was seen in S. sonei and S. flexneri (77% and 56%, respectively), whereas more than 90% of Salmonella serogroup B, C and D were susceptible to this antibiotic. In conclusion, Shigella and Salmonella serogroups can be considered as important etiological agents of acute diarrhea in children. Since the prevalence of antibiotic resistance is increasing in recent years in Iran, further

  6. Intracellular and membrane-damaging activities of methyl gallate isolated from Terminalia chebula against multidrug-resistant Shigella spp.

    Science.gov (United States)

    Acharyya, Saurabh; Sarkar, Prodipta; Saha, Dhira R; Patra, Amarendra; Ramamurthy, T; Bag, Prasanta K

    2015-08-01

    Shigella spp. (Shigella dysenteriae, Shigella flexneri, Shigella boydii and Shigella sonnei) cause bacillary dysentery (shigellosis), which is characterized by bloody mucous diarrhoea. Although a variety of antibiotics have been effective for treatment of shigellosis, options are becoming limited due to globally emerging drug resistance. In the present study, in vitro antibacterial activity of methyl gallate (MG) isolated from Terminalia chebula was determined by performing MIC, minimal bactericidal concentration (MBC) and time-kill kinetic studies. Bacterial membrane-damaging activity of MG was determined by membrane perturbation and transmission electron microscopy (TEM). Cellular drug accumulation, cell infection and assessment of intracellular activities of MG and reference antibiotics were performed using HeLa cell cultures. The bactericidal activity of MG against multidrug-resistant (MDR) Shigella spp. in comparison with other commonly used drugs including fluoroquinolone was demonstrated here. TEM findings in the present study revealed that MG caused the total disintegration of inner and outer membranes, and leakage of the cytoplasmic contents of S. dysenteriae. The level of accumulation of MG and tetracycline in HeLa cells incubated for 24  h was relatively higher than that of ciprofloxacin and nalidixic acid (ratio of intracellular concentration/extracellular concentration of antibiotic for MG and tetracycline>ciprofloxacin and nalidixic acid). The viable number of intracellular S. dysenteriae was decreased in a time-dependent manner in the presence of MG (4 × MBC) and reduced to zero within 20  h. The significant intracellular activities of MG suggested that it could potentially be used as an effective antibacterial agent for the treatment of severe infections caused by MDR Shigella spp.

  7. The changing epidemiology of bacillary dysentery and characteristics of antimicrobial resistance of Shigella isolated in China from 2004-2014.

    Science.gov (United States)

    Chang, Zhaorui; Zhang, Jing; Ran, Lu; Sun, Junling; Liu, Fengfeng; Luo, Li; Zeng, Lingjia; Wang, Liping; Li, Zhongjie; Yu, Hongjie; Liao, Qiaohong

    2016-11-18

    Bacillary dysentery caused by bacteria of the genus Shigella is a significant public health problem in developing countries such as China. The objective of this study was to analyze the epidemiological pattern of bacillary dysentery, the diversity of the causative agent, and the antimicrobial resistance patterns of Shigella spp. for the purpose of determining the most effective allocation of resources and prioritization of interventions. Surveillance data were acquired from the National Infectious Disease Information Reporting System (2004-2014) and from the sentinel hospital-based surveillance system (2005-2014). We analyzed the spatial and temporal distribution of bacillary dysentery, age and sex distribution, species diversity, and antimicrobial resistance patterns of Shigella spp. The surveillance registry included over 3 million probable cases of bacillary dysentery during the period 2004-2014. The annual incidence rate of bacillary dysentery decreased from 38.03 cases per 100,000 person-years in 2004 to 11.24 cases per 100,000 person-years in 2014. The case-fatality rate decreased from 0.028% in 2004 to 0.003% in 2014. Children aged Shigella flexneri was the most prevalent species that caused bacillary dysentery in China (63.86%), followed by Shigella sonnei (34.89%). Shigella isolates were highly resistant to nalidixic acid (89.13%), ampicillin (88.90%), tetracycline (88.43%), and sulfamethoxazole (82.92%). During the study period, isolates resistant to ciprofloxacin and cefotaxime increased from 8.53 and 7.87% in 2005 to 44.65 and 29.94% in 2014, respectively. The incidence rate of bacillary dysentery has undergone an obvious decrease from 2004 to 2014. Priority interventions should be delivered to populations in northwest China and to individuals aged Shigella is a serious public health problem and it is important to consider the susceptibility profile of isolates before determining treatment.

  8. Enteropathogenic Escherichia coli, Samonella, Shigella and Yersinia: cellular aspects of host-bacteria interactions in enteric diseases

    Directory of Open Access Journals (Sweden)

    Reis Roberta

    2010-07-01

    Full Text Available Abstract A successful infection of the human intestine by enteropathogenic bacteria depends on the ability of bacteria to attach and colonize the intestinal epithelium and, in some cases, to invade the host cell, survive intracellularly and disseminate from cell to cell. To accomplish these processes bacteria have evolved an arsenal of molecules that are mostly secreted by dedicated type III secretion systems, and that interact with the host, subverting normal cellular functions. Here we overview the most important molecular strategies developed by enteropathogenic Escherichia coli, Salmonella enterica, Shigella flexneri, and Yersinia enterocolitica to cause enteric infections. Despite having evolved different effectors, these four microorganisms share common host cellular targets.

  9. The importance of integrons for development and propagation of resistance in Shigella: the case of Latin America

    Directory of Open Access Journals (Sweden)

    Kenia Barrantes

    Full Text Available Abstract In Latin America, the disease burden of shigellosis is found to coexist with the rapid and rampant spread of resistance to commonly used antibiotics. The molecular basis of antibiotic resistance lies within genetic elements such as plasmids, transposons, integrons, genomic islands, etc., which are found in the bacterial genome. Integrons are known to acquire, exchange, and express genes within gene cassettes and it is hypothesized that they play a significant role in the transmission of multidrug resistance genes in several Gram-negative bacteria including Shigella. A few studies have described antibiotic resistance genes and integrons among multidrug resistant Shigella isolates found in Latin America. For example, in Brazil, Bolivia, Chile, Costa Rica and Peru, class 1 and class 2 integrons have been detected among multidrug resistant strains of Shigella; this phenomenon is more frequently observed in S. flexneri isolates that are resistant to trimethoprim, sulfamethoxazole, streptomycin, ampicillin, chloramphenicol, and tetracycline. The gene cassette sul2, which is frequently detected in Shigella strains resistant to the sulfonamides, suggests that the sulfonamide-resistant phenotype can be explained by the presence of the sul2 genes independent of the integron class detected. It is to be noted that sul3 was negative in all isolates analyzed in these studies.The high frequency of sulfonamide (as encoded by sul2 and trimethoprim resistance is likely to be a result of the recurrent use of trimethoprim sulfamethoxazole as a popular regimen for the treatment of shigellosis. The observed resistance profiles of Shigella strains confirm that ampicillin and trimethoprim-sulfamethoxazole are ineffective as therapeutic options. In-depth information regarding antibiotic resistance mechanism in this pathogen is needed in order to develop suitable intervention strategies. There is a pressing need for regional and local antimicrobial resistance

  10. Evaluation of the ability of four ESBL-screening media to detect ESBL-producing Salmonella and Shigella.

    Science.gov (United States)

    Sturød, Kjersti; Dahle, Ulf R; Berg, Einar Sverre; Steinbakk, Martin; Wester, Astrid L

    2014-09-04

    The aim of this study was to compare the ability of four commercially available media for screening extended-spectrum beta-lactamase (ESBL) to detect and identify ESBL-producing Salmonella and Shigella in fecal samples. A total of 71 Salmonella- and 21 Shigella-isolates producing ESBL(A) and/or AmpC, were received at Norwegian Institute of Public Health between 2005 and 2012. The 92 isolates were mixed with fecal specimens and tested on four ESBL screening media; ChromID ESBL (BioMèrieux), Brilliance ESBL (Oxoid), BLSE agar (AES Chemunex) and CHROMagar ESBL (CHROMagar). The BLSE agar is a biplate consisting of two different agars. Brilliance and CHROMagar are supposed to suppress growth of AmpC-producing bacteria while ChromID and BLSE agar are intended to detect both ESBL(A) and AmpC. The total sensitivity (ESBL(A)+AmpC) with 95% confidence intervals after 24 hours of incubation were as follows: ChromID: 95% (90.4-99.6), Brilliance: 93% (87.6-98.4), BLSE agar (Drigalski): 99% (96.9-100), BLSE agar (MacConkey): 99% (96.9-100) and CHROMagar: 85% (77.5-92.5). The BLSE agar identified Salmonella and Shigella isolates as lactose-negative. The other agars based on chromogenic technology displayed Salmonella and Shigella flexneri isolates with colorless colonies (as expected). Shigella sonnei produced pink colonies, similar to the morphology described for E. coli. All four agar media were reliable in screening fecal samples for ESBL(A)-producing Salmonella and Shigella. However, only ChromID and BLSE agar gave reliable detection of AmpC-producing isolates. Identification of different bacterial species based on colony colour alone was not accurate for any of the four agars.

  11. The importance of integrons for development and propagation of resistance in Shigella: the case of Latin America.

    Science.gov (United States)

    Barrantes, Kenia; Achí, Rosario

    In Latin America, the disease burden of shigellosis is found to coexist with the rapid and rampant spread of resistance to commonly used antibiotics. The molecular basis of antibiotic resistance lies within genetic elements such as plasmids, transposons, integrons, genomic islands, etc., which are found in the bacterial genome. Integrons are known to acquire, exchange, and express genes within gene cassettes and it is hypothesized that they play a significant role in the transmission of multidrug resistance genes in several Gram-negative bacteria including Shigella. A few studies have described antibiotic resistance genes and integrons among multidrug resistant Shigella isolates found in Latin America. For example, in Brazil, Bolivia, Chile, Costa Rica and Peru, class 1 and class 2 integrons have been detected among multidrug resistant strains of Shigella; this phenomenon is more frequently observed in S. flexneri isolates that are resistant to trimethoprim, sulfamethoxazole, streptomycin, ampicillin, chloramphenicol, and tetracycline. The gene cassette sul2, which is frequently detected in Shigella strains resistant to the sulfonamides, suggests that the sulfonamide-resistant phenotype can be explained by the presence of the sul2 genes independent of the integron class detected. It is to be noted that sul3 was negative in all isolates analyzed in these studies. The high frequency of sulfonamide (as encoded by sul2) and trimethoprim resistance is likely to be a result of the recurrent use of trimethoprim sulfamethoxazole as a popular regimen for the treatment of shigellosis. The observed resistance profiles of Shigella strains confirm that ampicillin and trimethoprim-sulfamethoxazole are ineffective as therapeutic options. In-depth information regarding antibiotic resistance mechanism in this pathogen is needed in order to develop suitable intervention strategies. There is a pressing need for regional and local antimicrobial resistance profiling of Shigella to be

  12. Oral administration of live Shigella vaccine candidates in rhesus monkeys show no evidence of competition for colonization and immunogenicity between different serotypes.

    Science.gov (United States)

    Ranallo, R T; Kaminski, R; Baqar, S; Dutta, M; Lugo-Roman, L A; Boren, T; Barnoy, S; Venkatesan, M M

    2014-03-26

    Live oral monovalent Shigella flexneri 2a vaccine candidates as well as bivalent formulations with Shigella sonnei were evaluated in a rhesus monkey model for colonization and immunogenicity. Freshly harvested suspensions of S. flexneri 2a vaccine candidates WRSf2G12 and WRSf2G15 as well as S. sonnei vaccine candidate WRSs3 were nasogastrically administered to groups of rhesus monkeys, Macaca mulatta, either in a monovalent form or when combined with each other. The animals were monitored daily for physical well-being, stools were subjected to quantitative colony immunoblot assays for bacterial excretion and blood and stools were evaluated for humoral and mucosal immune responses. No clinical symptoms were noted in any group of animals and the vaccine candidates were excreted robustly for 48-72h without significant changes in either the magnitude or duration of excretion when given as a monovalent or as bivalent mixtures. Similarly, immunological interferences were not apparent in the magnitude of humoral and mucosal immune responses observed toward Shigella-specific antigens when monkeys were fed monovalent or bivalent formulations. These results predict that a multivalent live oral vaccine of more than one serotype can have a favorable outcome for protection against shigellosis. Published by Elsevier Ltd.

  13. A Brief History of Shigella.

    Science.gov (United States)

    Lampel, Keith A; Formal, Samuel B; Maurelli, Anthony T

    2018-01-01

    The history of Shigella , the causative agent of bacillary dysentery, is a long and fascinating one. This brief historical account starts with descriptions of the disease and its impact on human health from ancient time to the present. Our story of the bacterium starts just before the identification of the dysentery bacillus by Kiyoshi Shiga in 1898 and follows the scientific discoveries and principal scientists who contributed to the elucidation of Shigella pathogenesis in the first 100 years. Over the past century, Shigella has proved to be an outstanding model of an invasive bacterial pathogen and has served as a paradigm for the study of other bacterial pathogens. In addition to invasion of epithelial cells, some of those shared virulence traits include toxin production, multiple-antibiotic resistance, virulence genes encoded on plasmids and bacteriophages, global regulation of virulence genes, pathogenicity islands, intracellular motility, remodeling of host cytoskeleton, inflammation/polymorphonuclear leukocyte signaling, apoptosis induction/inhibition, and "black holes" and antivirulence genes. While there is still much to learn from studying Shigella pathogenesis, what we have learned so far has also contributed greatly to our broader understanding of bacterial pathogenesis.

  14. Shigella Sonnei and Shiga Toxin

    Centers for Disease Control (CDC) Podcasts

    2016-07-28

    Katherine Lamba, an infectious disease epidemiologist with the California Department of Public Health, discusses Shiga Toxin producing Shigella sonnei.  Created: 7/28/2016 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 7/28/2016.

  15. Host and bacterial proteins that repress recruitment of LC3 to Shigella early during infection.

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    Leigh A Baxt

    Full Text Available Shigella spp. are intracytosolic gram-negative pathogens that cause disease by invasion and spread through the colonic mucosa, utilizing host cytoskeletal components to form propulsive actin tails. We have previously identified the host factor Toca-1 as being recruited to intracellular S. flexneri and being required for efficient bacterial actin tail formation. We show that at early times during infection (40 min., the type three-secreted effector protein IcsB recruits Toca-1 to intracellular bacteria and that recruitment of Toca-1 is associated with repression of recruitment of LC3, as well as with repression of recruitment of the autophagy marker NDP52, around these intracellular bacteria. LC3 is best characterized as a marker of autophagosomes, but also marks phagosomal membranes in the process LC3-associated phagocytosis. IcsB has previously been demonstrated to be required for S. flexneri evasion of autophagy at late times during infection (4-6 hr by inhibiting binding of the autophagy protein Atg5 to the Shigella surface protein IcsA (VirG. Our results suggest that IcsB and Toca-1 modulation of LC3 recruitment restricts LC3-associated phagocytosis and/or LC3 recruitment to vacuolar membrane remnants. Together with published results, our findings suggest that IcsB inhibits innate immune responses in two distinct ways, first, by inhibiting LC3-associated phagocytosis and/or LC3 recruitment to vacuolar membrane remnants early during infection, and second, by inhibiting autophagy late during infection.

  16. Combining Shigella Tn-seq data with gold-standard E. coli gene deletion data suggests rare transitions between essential and non-essential gene functionality.

    Science.gov (United States)

    Freed, Nikki E; Bumann, Dirk; Silander, Olin K

    2016-09-06

    Gene essentiality - whether or not a gene is necessary for cell growth - is a fundamental component of gene function. It is not well established how quickly gene essentiality can change, as few studies have compared empirical measures of essentiality between closely related organisms. Here we present the results of a Tn-seq experiment designed to detect essential protein coding genes in the bacterial pathogen Shigella flexneri 2a 2457T on a genome-wide scale. Superficial analysis of this data suggested that 481 protein-coding genes in this Shigella strain are critical for robust cellular growth on rich media. Comparison of this set of genes with a gold-standard data set of essential genes in the closely related Escherichia coli K12 BW25113 revealed that an excessive number of genes appeared essential in Shigella but non-essential in E. coli. Importantly, and in converse to this comparison, we found no genes that were essential in E. coli and non-essential in Shigella, implying that many genes were artefactually inferred as essential in Shigella. Controlling for such artefacts resulted in a much smaller set of discrepant genes. Among these, we identified three sets of functionally related genes, two of which have previously been implicated as critical for Shigella growth, but which are dispensable for E. coli growth. The data presented here highlight the small number of protein coding genes for which we have strong evidence that their essentiality status differs between the closely related bacterial taxa E. coli and Shigella. A set of genes involved in acetate utilization provides a canonical example. These results leave open the possibility of developing strain-specific antibiotic treatments targeting such differentially essential genes, but suggest that such opportunities may be rare in closely related bacteria.

  17. Radioprotective activity of shigella antigens

    International Nuclear Information System (INIS)

    Klemparskaya, N.N.; Gorbunova, E.S.; Dobronravova, N.N.

    1981-01-01

    The possibility of using experimental microbe antigenous preparation out of Flexner and Zonne shigellas as a protector and a remedy in the case of gamma irradiation, is investigated. The experiments are carried out on mice of both sexes immunized before or after irradiation by two methods: subcutaneously and enerally. It is found that in most cases investigated, the introduction of the experimental preparation 3, 5, 7 and 10 days before irradiation increases the survivability of animals [ru

  18. Shigella entry unveils a calcium/calpain-dependent mechanism for inhibiting sumoylation

    Science.gov (United States)

    Lhocine, Nouara; Andrieux, Alexandra; Nigro, Giulia; Mounier, Joëlle

    2017-01-01

    Disruption of the sumoylation/desumoylation equilibrium is associated with several disease states such as cancer and infections, however the mechanisms regulating the global SUMO balance remain poorly defined. Here, we show that infection by Shigella flexneri, the causative agent of human bacillary dysentery, switches off host sumoylation during epithelial cell infection in vitro and in vivo and that this effect is mainly mediated by a calcium/calpain-induced cleavage of the SUMO E1 enzyme SAE2, thus leading to sumoylation inhibition. Furthermore, we describe a mechanism by which Shigella promotes its own invasion by altering the sumoylation state of RhoGDIα, a master negative regulator of RhoGTPase activity and actin polymerization. Together, our data suggest that SUMO modification is essential to restrain pathogenic bacterial entry by limiting cytoskeletal rearrangement induced by bacterial effectors. Moreover, these findings identify calcium-activated calpains as powerful modulators of cellular sumoylation levels with potentially broad implications in several physiological and pathological situations. PMID:29231810

  19. Shigella Vulvovaginitis in Childhood: A Case Report

    Science.gov (United States)

    Rajkumar, Solomon; Narayanaswamy, Geetha; Laude, Teresita Awa

    1979-01-01

    Vulvovaginitis due to Shigella sonnei is reported in a four-year-old child. Shigella sonnei as a rare primary pathogen causing vulvovaginitis, the prolonged nature of the clinical course, and the therapeutic implications of increasing resistance to ampicillin by the organism are discussed. PMID:395325

  20. Co-administration of rIpaB domain of Shigella with rGroEL of S. Typhi enhances the immune responses and protective efficacy against Shigella infection.

    Science.gov (United States)

    Chitradevi, Sekar Tamil Selvi; Kaur, Gurpreet; Uppalapati, Sivaramakrishna; Yadav, Anandprakash; Singh, Dependrapratap; Bansal, Anju

    2015-11-01

    Shigella species cause severe bacillary dysentery in humans and are associated with high morbidity and mortality. The Invasion plasmid antigen (IpaB) protein, which is conserved across all Shigella spp., induces macrophage cell death and is required to invade host cells. The present study evaluates the immunogenicity and protective efficacy of the recombinant (r) domain region of IpaB (rIpaB) of S. flexneri. rIpaB was administered either alone or was co-administered with the rGroEL (heat shock protein 60) protein from S. Typhi as an adjuvant in a mouse model of intranasal immunization. The IpaB domain region (37 kDa) of S. flexneri was amplified from an invasion plasmid, cloned, expressed in BL21 Escherichia coli cells and purified. Immunization with the rIpaB domain alone stimulated both humoral and cell-mediated immune responses. Furthermore, robust antibody (IgG, IgA) and T-cell responses were induced when the rIpaB domain was co-administered with rGroEL. Antibody isotyping revealed higher IgG1 and IgG2a antibody titers and increased interferon-gamma (IFN-γ) secretion in the co-administered group. Immunization of mice with the rIpaB domain alone protected 60%-70% of the mice from lethal infection by S. flexneri, S. boydii and S. sonnei, whereas co-administration with rGroEL increased the protective efficacy to 80%-85%. Organ burden and histopathological studies also revealed a significant reduction in lung infection in the co-immunized mice compared with mice immunized with the rIpaB domain alone. This study emphasizes that the co-administration of the rIpaB domain and rGroEL protein improves immune responses in mice and increases protective efficacy against Shigella infection. This is also the first report to evaluate the potential of the GroEL (Hsp 60) protein of S. Typhi as an adjuvant molecule, thereby overcoming the need for commercial adjuvants.

  1. Isolation and molecular characterization of Salmonella enterica, Escherichia coli O157:H7 and Shigella spp. from meat and dairy products in Egypt.

    Science.gov (United States)

    Ahmed, Ashraf M; Shimamoto, Tadashi

    2014-01-03

    Foodborne pathogens are a major threat to food safety, especially in developing countries where hygiene and sanitation facilities are often poor. Salmonella enterica, Escherichia coli O157:H7 and Shigella spp. are among the major causes of outbreaks of foodborne diseases. This large-scale study investigated the prevalence of these foodborne pathogens in meat (beef and chicken) and dairy products collected from street vendors, butchers, retail markets and slaughterhouses in Egypt. A total of 1600 food samples (800 meat products and 800 dairy products) were analyzed using culture and PCR based methods. S. enterica, E. coli O157:H7 and Shigella spp. were detected in 69 (4.3%), 54 (3.4%) and 27 (1.7%) samples respectively. S. enterica serovar Typhimurium, S. enterica serovar Enteritidis, S. enterica serovar Infantis and non-typable serovars were detected in 28 (1.8%), 22 (1.4%), 16 (1.0%) and 3 (0.1%) samples respectively. All E. coli O157:H7 isolates were positive for stx1 and/or stx2 virulence toxin genes. Shigella flexneri, Shigella sonnei and Shigella dysenteriae were detected in 18 (1.2%), 7 (0.4%) and 2 (0.1%) samples respectively. The incidences of S. enterica and Shigella spp. were higher in meat products (53; 6.6% and 16; 2.0%, respectively) than in dairy products (16; 2.0% and 11; 1.4%, respectively), while, E. coli O157:H7 was higher in dairy products (29; 3.6%) than in meat products (25; 3.1%). The incidence of foodborne pathogens in meat and dairy products was determined in a large-scale survey in Africa. © 2013.

  2. Changing emergence of Shigella sero-groups in Bangladesh: observation from four different diarrheal disease hospitals.

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    Sumon Kumar Das

    Full Text Available BACKGROUND: Shigellosis continues to be a public health challenge for developing countries, including Bangladesh. The aim of the study is to demonstrate recent changes in Shigella sero-groups and their geographical diversity. METHODS: Data were extracted from data archive of four diarrheal disease surveillance systems. A 2% sub sample from urban Dhaka Hospital (2008-2011; n = 10,650, and 10% from urban Mirpur Treatment Centre (2009-2011; n = 3,585, were enrolled systematically; whereas, all patients coming from the Health and Demographic Surveillance System area in rural Matlab (2008-2011; n = 6,399 and rural Mirzapur (2010-2011; n = 2,812 were included irrespective of age, sex, and disease severity. A fresh stool specimen was collected for identification of Shigella spp. Of them, 315 (3% were positive for Shigella in Dhaka, 490 (8% from Matlab, 109 (3% from Mirpur and 369 (13% from Mirzapur and considered as analyzable sample size. RESULTS: Among all Shigella isolates regardless of age, significant decreases in percentage of S. flexneri over time was observed in Mirpur (55→29%; p value of χ(2-for trend = 0.019 and Mirzapur (59→47%; p = 0.025. A non-significant decrease was also seen in Dhaka (58→48%, while in Matlab there was a non-significant increase (73→81%. Similar patterns were observed among under-5 children at all sites. Emergence of S. sonnei was found in Dhaka (8→25%; p<0.001 and Mirpur (10→33%; p = 0.015, whereas it decreased in Mirzapur (32→23%; p = 0.056. The emergence of S. boydii was seen in all ages in Mirzapur [(3→28%; p<0.001; (3→27%; p<0.001]. On the other hand, we saw non-significant percent reductions in S. boydii in Dhaka [overall (25→16%; under-5 (16→9%]. Decreasing rates of Shigella dysenteriae were observed in Matlab, Mirpur and Mirzapur; whereas, in Dhaka it remained unchanged. CONCLUSION AND SIGNIFICANCE: Emergence of S. sonnei and S. boydii as important infectious

  3. Changing Emergence of Shigella Sero-Groups in Bangladesh: Observation from Four Different Diarrheal Disease Hospitals

    Science.gov (United States)

    Das, Sumon Kumar; Ahmed, Shahnawaz; Ferdous, Farzana; Farzana, Fahmida Dil; Chisti, Mohammod Jobayer; Leung, Daniel T.; Malek, Mohammad Abdul; Talukder, Kaisar Ali; Bardhan, Pradip Kumar; Salam, Mohammed Abdus; Faruque, Abu Syed Golam; Raqib, Rubhana

    2013-01-01

    Background Shigellosis continues to be a public health challenge for developing countries, including Bangladesh. The aim of the study is to demonstrate recent changes in Shigella sero-groups and their geographical diversity. Methods Data were extracted from data archive of four diarrheal disease surveillance systems. A 2% sub sample from urban Dhaka Hospital (2008–2011; n = 10,650), and 10% from urban Mirpur Treatment Centre (2009–2011; n = 3,585), were enrolled systematically; whereas, all patients coming from the Health and Demographic Surveillance System area in rural Matlab (2008–2011; n = 6,399) and rural Mirzapur (2010–2011; n = 2,812) were included irrespective of age, sex, and disease severity. A fresh stool specimen was collected for identification of Shigella spp. Of them, 315 (3%) were positive for Shigella in Dhaka, 490 (8%) from Matlab, 109 (3%) from Mirpur and 369 (13%) from Mirzapur and considered as analyzable sample size. Results Among all Shigella isolates regardless of age, significant decreases in percentage of S. flexneri over time was observed in Mirpur (55→29%; p value of χ2-for trend = 0.019) and Mirzapur (59→47%; p = 0.025). A non-significant decrease was also seen in Dhaka (58→48%), while in Matlab there was a non-significant increase (73→81%). Similar patterns were observed among under-5 children at all sites. Emergence of S. sonnei was found in Dhaka (8→25%; pp = 0.015), whereas it decreased in Mirzapur (32→23%; p = 0.056). The emergence of S. boydii was seen in all ages in Mirzapur [(3→28%; pp<0.001)]. On the other hand, we saw non-significant percent reductions in S. boydii in Dhaka [overall (25→16%); under-5 (16→9%)]. Decreasing rates of Shigella dysenteriae were observed in Matlab, Mirpur and Mirzapur; whereas, in Dhaka it remained unchanged. Conclusion and Significance Emergence of S. sonnei and S. boydii as important infectious diarrhea etiologies and variations in

  4. The changing epidemiology of bacillary dysentery and characteristics of antimicrobial resistance of Shigella isolated in China from 2004–2014

    Directory of Open Access Journals (Sweden)

    Zhaorui Chang

    2016-11-01

    Full Text Available Abstract Background Bacillary dysentery caused by bacteria of the genus Shigella is a significant public health problem in developing countries such as China. The objective of this study was to analyze the epidemiological pattern of bacillary dysentery, the diversity of the causative agent, and the antimicrobial resistance patterns of Shigella spp. for the purpose of determining the most effective allocation of resources and prioritization of interventions. Methods Surveillance data were acquired from the National Infectious Disease Information Reporting System (2004–2014 and from the sentinel hospital-based surveillance system (2005–2014. We analyzed the spatial and temporal distribution of bacillary dysentery, age and sex distribution, species diversity, and antimicrobial resistance patterns of Shigella spp. Results The surveillance registry included over 3 million probable cases of bacillary dysentery during the period 2004–2014. The annual incidence rate of bacillary dysentery decreased from 38.03 cases per 100,000 person-years in 2004 to 11.24 cases per 100,000 person-years in 2014. The case-fatality rate decreased from 0.028% in 2004 to 0.003% in 2014. Children aged <1 year and 1–4 years were most affected, with higher incidence rates (228.59 cases per 100,000 person-years and 92.58 cases per 100,000 person-years respectively. The annual epidemic season occurred between June and September. A higher incidence rate of bacillary dysentery was found in the Northwest region, Beijing and Tianjin during the study period. Shigella flexneri was the most prevalent species that caused bacillary dysentery in China (63.86%, followed by Shigella sonnei (34.89%. Shigella isolates were highly resistant to nalidixic acid (89.13%, ampicillin (88.90%, tetracycline (88.43%, and sulfamethoxazole (82.92%. During the study period, isolates resistant to ciprofloxacin and cefotaxime increased from 8.53 and 7.87% in 2005 to 44.65 and 29.94% in 2014

  5. Comparative Genomic and Phylogenetic Analysis of a Shiga Toxin Producing Shigella sonnei (STSS Strain

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    Domonkos Sváb

    2017-05-01

    Full Text Available Shigella strains are important agents of bacillary dysentery, and in recent years Shigella sonnei has emerged as the leading cause of shigellosis in industrialized and rapidly developing countries. More recently, several S. sonnei and Shigella flexneri strains producing Shiga toxin (Stx have been reported from sporadic cases and from an outbreak in America. In the present study we aimed to shed light on the evolution of a recently identified Shiga toxin producing S. sonnei (STSS isolated in Europe. Here we report the first completely assembled whole genome sequence of a multidrug resistant (MDR Stx-producing S. sonnei (STSS clinical strain and reveal its phylogenetic relations. STSS 75/02 proved to be resistant to ampicillin, streptomycin, tetracycline, chloramphenicol, thrimetoprim, and sulfomethoxazol. The genome of STSS 75/02 contains a 4,891,717 nt chromosome and seven plasmids including the 214 kb invasion plasmid (pInv harboring type III secretion system genes and associated effectors. The chromosome harbors 23 prophage regions including the Stx1 converting prophage. The genome carries all virulence determinants necessary for an enteroinvasive lifestyle, as well as the Stx1 encoding gene cluster within an earlier described inducible converting prophage. In silico SNP genotyping of the assembled genome as well as 438 complete or draft S. sonnei genomes downloaded from NCBI GenBank revealed that S. sonnei 75/02 belongs to the more recently diverged global MDR lineage (IIIc. Targeted screening of 1131 next-generation sequencing projects taken from NCBI Short Read Archive of confirms that only a few S. sonnei isolates are Stx positive. Our results suggest that the acquisition of Stx phages could have occurred in different environments as independent events and that multiple horizontal transfers are responsible for the appearance of Stx phages in S. sonnei strains.

  6. Progress and pitfalls in Shigella vaccine research

    Science.gov (United States)

    Barry, Eileen M.; Pasetti, Marcela F.; Sztein, Marcelo B.; Fasano, Alessio; Kotloff, Karen L.; Levine, Myron M.

    2013-01-01

    Renewed awareness of the significant morbidity and mortality that Shigella causes among young children in developing countries combined with technological innovations in vaccinology has led to the development of novel vaccine strategies in the past five years. Along with advancement of classical vaccines in clinical trials and new sophisticated measurements of immunological responses, much new data has been produced lending promise to the potential for production of safe and effective Shigella vaccines. Herein we review the recent progress in Shigella vaccine development within the framework of persistent obstacles. PMID:23419287

  7. Genetic plasticity of the Shigella virulence plasmid is mediated by intra- and inter-molecular events between insertion sequences.

    Science.gov (United States)

    Pilla, Giulia; McVicker, Gareth; Tang, Christoph M

    2017-09-01

    Acquisition of a single copy, large virulence plasmid, pINV, led to the emergence of Shigella spp. from Escherichia coli. The plasmid encodes a Type III secretion system (T3SS) on a 30 kb pathogenicity island (PAI), and is maintained in a bacterial population through a series of toxin:antitoxin (TA) systems which mediate post-segregational killing (PSK). The T3SS imposes a significant cost on the bacterium, and strains which have lost the plasmid and/or genes encoding the T3SS grow faster than wild-type strains in the laboratory, and fail to bind the indicator dye Congo Red (CR). Our aim was to define the molecular events in Shigella flexneri that cause loss of Type III secretion (T3S), and to examine whether TA systems exert positional effects on pINV. During growth at 37°C, we found that deletions of regions of the plasmid including the PAI lead to the emergence of CR-negative colonies; deletions occur through intra-molecular recombination events between insertion sequences (ISs) flanking the PAI. Furthermore, by repositioning MvpAT (which belongs to the VapBC family of TA systems) near the PAI, we demonstrate that the location of this TA system alters the rearrangements that lead to loss of T3S, indicating that MvpAT acts both globally (by reducing loss of pINV through PSK) as well as locally (by preventing loss of adjacent sequences). During growth at environmental temperatures, we show for the first time that pINV spontaneously integrates into different sites in the chromosome, and this is mediated by inter-molecular events involving IS1294. Integration leads to reduced PAI gene expression and impaired secretion through the T3SS, while excision of pINV from the chromosome restores T3SS function. Therefore, pINV integration provides a reversible mechanism for Shigella to circumvent the metabolic burden imposed by pINV. Intra- and inter-molecular events between ISs, which are abundant in Shigella spp., mediate plasticity of S. flexneri pINV.

  8. Resistencia a antibióticos y epidemiología molecular de Shigella spp. en el nordeste argentino

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    Luis A. Merino

    2004-04-01

    Full Text Available OBJETIVOS: Evaluar la resistencia a antibióticos de cepas de Shigella spp. aisladas de muestras de heces en el nordeste argentino y caracterizarlas desde el punto de vista de su epidemiología molecular. MÉTODOS: Se estudiaron 132 aislamientos de Shigella spp. obtenidos de las heces de igual número de pacientes con diarrea que asistieron a diferentes laboratorios privados y estatales de las provincias del Chaco y Corrientes, Argentina, durante el período de 1998 a 2002. Cada cepa se caracterizó según su serotipo, su resistencia a 13 antibióticos individuales o combinados y su sensibilidad a las piocinas. A 52 cepas seleccionadas en función de sus perfiles de susceptibilidad antimicrobiana se les determinaron la dotación plasmídica mediante lisis alcalina y las secuencias repetitivas palindrómicas extragénicas mediante la amplificación de segmentos repetitivos de ADN con la reacción en cadena de la polimerasa (REP-RCP. Se aplicó la prueba de ji al cuadrado para comparar proporciones. El nivel de significación estadística fue de 0,05. RESULTADOS: Shigella flexneri fue la especie más frecuente (78%, seguida de S. sonnei (22%. En general, la resistencia de S. flexneri a los antibióticos estudiados fue mayor que la de S. sonnei y esta diferencia fue estadísticamente significativa (P <0,001 frente a ampicilina, tetraciclina, cloramfenicol y la combinación de ampicilina con sulbactama. Las cepas de S. flexneri también mostraron mayor multirresistencia que las de S. sonnei (84,5% frente a 31,0%; P <0,001. Las cepas aisladas de S. flexneri pudieron agruparse según 5 piocinotipos, 3 perfiles plasmídicos y 5 patrones de secuencias repetitivas palindrómicas. Por su parte, las cepas de S. sonnei conformaron 3 piocinotipos, 2 perfiles plasmídicos y 3 patrones de secuencias repetitivas palindrómicas. CONCLUSIONES: Las especies de Shigella estudiadas mostraron una elevada resistencia a los antibióticos de uso más frecuente, por lo

  9. An 11-year study of shigellosis and Shigella species in Taiyuan, China: Active surveillance, epidemic characteristics, and molecular serotyping

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    Lifeng Zhao

    2017-11-01

    Full Text Available A hospital-based surveillance of shigellosis was conducted in Taiyuan from 2005 to 2015. A total of 2655 stool cultures were collected from patients with diarrhea, 115 were identified as S. flexneri and 107 were S. sonnei. The highest infection rates were found among children under 5 years of age (34.2 %, and during the summer (61.0 %. ​Six serotypes were identified among S. flexneriisolates:1a, 2a, 2b, Xv, X and Y. Serotype 2a and Xv were the dominant serotypes in two periods, 2012–2015 and 2005–2008, respectively. High shigellosis rates over the past decade highlight shigellosis is still a major public health problem in Taiyuan. Keywords: Shigellosis, Shigella, Infection rate, Serotypes, Molecular serotyping

  10. Use of zebrafish to study Shigella infection

    Science.gov (United States)

    Duggan, Gina M.

    2018-01-01

    ABSTRACT Shigella is a leading cause of dysentery worldwide, responsible for up to 165 million cases of shigellosis each year. Shigella is also recognised as an exceptional model pathogen to study key issues in cell biology and innate immunity. Several infection models have been useful to explore Shigella biology; however, we still lack information regarding the events taking place during the Shigella infection process in vivo. Here, we discuss a selection of mechanistic insights recently gained from studying Shigella infection of zebrafish (Danio rerio), with a focus on cytoskeleton rearrangements and cellular immunity. We also discuss how infection of zebrafish can be used to investigate new concepts underlying infection control, including emergency granulopoiesis and the use of predatory bacteria to combat antimicrobial resistance. Collectively, these insights illustrate how Shigella infection of zebrafish can provide fundamental advances in our understanding of bacterial pathogenesis and vertebrate host defence. This information should also provide vital clues for the discovery of new therapeutic strategies against infectious disease in humans. PMID:29590642

  11. Use of zebrafish to study Shigella infection

    Directory of Open Access Journals (Sweden)

    Gina M. Duggan

    2018-02-01

    Full Text Available Shigella is a leading cause of dysentery worldwide, responsible for up to 165 million cases of shigellosis each year. Shigella is also recognised as an exceptional model pathogen to study key issues in cell biology and innate immunity. Several infection models have been useful to explore Shigella biology; however, we still lack information regarding the events taking place during the Shigella infection process in vivo. Here, we discuss a selection of mechanistic insights recently gained from studying Shigella infection of zebrafish (Danio rerio, with a focus on cytoskeleton rearrangements and cellular immunity. We also discuss how infection of zebrafish can be used to investigate new concepts underlying infection control, including emergency granulopoiesis and the use of predatory bacteria to combat antimicrobial resistance. Collectively, these insights illustrate how Shigella infection of zebrafish can provide fundamental advances in our understanding of bacterial pathogenesis and vertebrate host defence. This information should also provide vital clues for the discovery of new therapeutic strategies against infectious disease in humans.

  12. Shigella IpaB and IpaD displayed on L. lactis bacterium-like particles induce protective immunity in adult and infant mice.

    Science.gov (United States)

    Heine, Shannon J; Franco-Mahecha, Olga L; Chen, Xiaotong; Choudhari, Shyamal; Blackwelder, William C; van Roosmalen, Maarten L; Leenhouts, Kees; Picking, Wendy L; Pasetti, Marcela F

    2015-08-01

    Shigella spp. are among the enteric pathogens with the highest attributable incidence of moderate-to-severe diarrhea in children under 5 years of age living in endemic areas. There are no vaccines available to prevent this disease. In this work, we investigated a new Shigella vaccine concept consisting of nonliving, self-adjuvanted, Lactococcus lactis bacterium-like particles (BLP) displaying Shigella invasion plasmid antigen (Ipa) B and IpaD and examined its immunogenicity and protective efficacy in adult and newborn/infant mice immunized via the nasal route. Unique advantages of this approach include the potential for broad protection due to the highly conserved structure of the Ipas and the safety and practicality of a probiotic-based mucosal/adjuvant delivery platform. Immunization of adult mice with BLP-IpaB and BLP-IpaD (BLP-IpaB/D) induced high levels of Ipa-specific serum IgG and stool IgA in a dose-dependent manner. Immune responses and protection were enhanced by BLP delivery. Vaccine-induced serum antibodies exhibited opsonophagocytic and cytotoxic neutralizing activity, and IpaB/D IgG titers correlated with increased survival post-challenge. Ipa-specific antibody secreting cells were detected in nasal tissue and lungs, as well as IgG in bronchoalveolar lavage. Bone marrow cells produced IpaB/D-specific antibodies and contributed to protection after adoptive transfer. The BLP-IpaB/D vaccine conferred 90% and 80% protection against S. flexneri and S. sonnei, respectively. Mice immunized with BLP-IpaB/D as newborns also developed IpaB and IpaD serum antibodies; 90% were protected against S. flexneri and 44% against S. sonnei. The BLP-IpaB/D vaccine is a promising candidate for safe, practical and potentially effective immunization of children against shigellosis.

  13. Modulation of endotoxicity of Shigella generalized modules for membrane antigens (GMMA) by genetic lipid A modifications: relative activation of TLR4 and TLR2 pathways in different mutants.

    Science.gov (United States)

    Rossi, Omar; Pesce, Isabella; Giannelli, Carlo; Aprea, Susanna; Caboni, Mariaelena; Citiulo, Francesco; Valentini, Sara; Ferlenghi, Ilaria; MacLennan, Calman Alexander; D'Oro, Ugo; Saul, Allan; Gerke, Christiane

    2014-09-05

    Outer membrane particles from Gram-negative bacteria are attractive vaccine candidates as they present surface antigens in their natural context. We previously developed a high yield production process for genetically derived particles, called generalized modules for membrane antigens (GMMA), from Shigella. As GMMA are derived from the outer membrane, they contain immunostimulatory components, especially lipopolysaccharide (LPS). We examined ways of reducing their reactogenicity by modifying lipid A, the endotoxic part of LPS, through deletion of late acyltransferase genes, msbB or htrB, in GMMA-producing Shigella sonnei and Shigella flexneri strains. GMMA with resulting penta-acylated lipid A from the msbB mutants showed a 600-fold reduced ability, and GMMA from the S. sonnei ΔhtrB mutant showed a 60,000-fold reduced ability compared with GMMA with wild-type lipid A to stimulate human Toll-like receptor 4 (TLR4) in a reporter cell line. In human peripheral blood mononuclear cells, GMMA with penta-acylated lipid A showed a marked reduction in induction of inflammatory cytokines (S. sonnei ΔhtrB, 800-fold; ΔmsbB mutants, 300-fold). We found that the residual activity of these GMMA is largely due to non-lipid A-related TLR2 activation. In contrast, in the S. flexneri ΔhtrB mutant, a compensatory lipid A palmitoleoylation resulted in GMMA with hexa-acylated lipid A with ∼10-fold higher activity to stimulate peripheral blood mononuclear cells than GMMA with penta-acylated lipid A, mostly due to retained TLR4 activity. Thus, for use as vaccines, GMMA will likely require lipid A penta-acylation. The results identify the relative contributions of TLR4 and TLR2 activation by GMMA, which need to be taken into consideration for GMMA vaccine development. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

  14. Analysis of host microRNA function uncovers a role for miR-29b-2-5p in Shigella capture by filopodia.

    Science.gov (United States)

    Sunkavalli, Ushasree; Aguilar, Carmen; Silva, Ricardo Jorge; Sharan, Malvika; Cruz, Ana Rita; Tawk, Caroline; Maudet, Claire; Mano, Miguel; Eulalio, Ana

    2017-04-01

    MicroRNAs play an important role in the interplay between bacterial pathogens and host cells, participating as host defense mechanisms, as well as exploited by bacteria to subvert host cellular functions. Here, we show that microRNAs modulate infection by Shigella flexneri, a major causative agent of bacillary dysentery in humans. Specifically, we characterize the dual regulatory role of miR-29b-2-5p during infection, showing that this microRNA strongly favors Shigella infection by promoting both bacterial binding to host cells and intracellular replication. Using a combination of transcriptome analysis and targeted high-content RNAi screening, we identify UNC5C as a direct target of miR-29b-2-5p and show its pivotal role in the modulation of Shigella binding to host cells. MiR-29b-2-5p, through repression of UNC5C, strongly enhances filopodia formation thus increasing Shigella capture and promoting bacterial invasion. The increase of filopodia formation mediated by miR-29b-2-5p is dependent on RhoF and Cdc42 Rho-GTPases. Interestingly, the levels of miR-29b-2-5p, but not of other mature microRNAs from the same precursor, are decreased upon Shigella replication at late times post-infection, through degradation of the mature microRNA by the exonuclease PNPT1. While the relatively high basal levels of miR-29b-2-5p at the start of infection ensure efficient Shigella capture by host cell filopodia, dampening of miR-29b-2-5p levels later during infection may constitute a bacterial strategy to favor a balanced intracellular replication to avoid premature cell death and favor dissemination to neighboring cells, or alternatively, part of the host response to counteract Shigella infection. Overall, these findings reveal a previously unappreciated role of microRNAs, and in particular miR-29b-2-5p, in the interaction of Shigella with host cells.

  15. Analysis of host microRNA function uncovers a role for miR-29b-2-5p in Shigella capture by filopodia.

    Directory of Open Access Journals (Sweden)

    Ushasree Sunkavalli

    2017-04-01

    Full Text Available MicroRNAs play an important role in the interplay between bacterial pathogens and host cells, participating as host defense mechanisms, as well as exploited by bacteria to subvert host cellular functions. Here, we show that microRNAs modulate infection by Shigella flexneri, a major causative agent of bacillary dysentery in humans. Specifically, we characterize the dual regulatory role of miR-29b-2-5p during infection, showing that this microRNA strongly favors Shigella infection by promoting both bacterial binding to host cells and intracellular replication. Using a combination of transcriptome analysis and targeted high-content RNAi screening, we identify UNC5C as a direct target of miR-29b-2-5p and show its pivotal role in the modulation of Shigella binding to host cells. MiR-29b-2-5p, through repression of UNC5C, strongly enhances filopodia formation thus increasing Shigella capture and promoting bacterial invasion. The increase of filopodia formation mediated by miR-29b-2-5p is dependent on RhoF and Cdc42 Rho-GTPases. Interestingly, the levels of miR-29b-2-5p, but not of other mature microRNAs from the same precursor, are decreased upon Shigella replication at late times post-infection, through degradation of the mature microRNA by the exonuclease PNPT1. While the relatively high basal levels of miR-29b-2-5p at the start of infection ensure efficient Shigella capture by host cell filopodia, dampening of miR-29b-2-5p levels later during infection may constitute a bacterial strategy to favor a balanced intracellular replication to avoid premature cell death and favor dissemination to neighboring cells, or alternatively, part of the host response to counteract Shigella infection. Overall, these findings reveal a previously unappreciated role of microRNAs, and in particular miR-29b-2-5p, in the interaction of Shigella with host cells.

  16. 21 CFR 866.3660 - Shigella spp. serological reagents.

    Science.gov (United States)

    2010-04-01

    ... (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3660 Shigella spp...), used in serological tests to identify Shigella spp. from cultured isolates. The identification aids in...

  17. The Rising Dominance of Shigella sonnei: An Intercontinental Shift in the Etiology of Bacillary Dysentery.

    Directory of Open Access Journals (Sweden)

    Corinne N Thompson

    Full Text Available Shigellosis is the major global cause of dysentery. Shigella sonnei, which has historically been more commonly isolated in developed countries, is undergoing an unprecedented expansion across industrializing regions in Asia, Latin America, and the Middle East. The precise reasons underpinning the epidemiological distribution of the various Shigella species and this global surge in S. sonnei are unclear but may be due to three major environmental pressures. First, natural passive immunization with the bacterium Plesiomonas shigelloides is hypothesized to protect populations with poor water supplies against S. sonnei. Improving the quality of drinking water supplies would, therefore, result in a reduction in P. shigelloides exposure and a subsequent reduction in environmental immunization against S. sonnei. Secondly, the ubiquitous amoeba species Acanthamoeba castellanii has been shown to phagocytize S. sonnei efficiently and symbiotically, thus allowing the bacteria access to a protected niche in which to withstand chlorination and other harsh environmental conditions in temperate countries. Finally, S. sonnei has emerged from Europe and begun to spread globally only relatively recently. A strong selective pressure from localized antimicrobial use additionally appears to have had a dramatic impact on the evolution of the S. sonnei population. We hypothesize that S. sonnei, which exhibits an exceptional ability to acquire antimicrobial resistance genes from commensal and pathogenic bacteria, has a competitive advantage over S. flexneri, particularly in areas with poorly regulated antimicrobial use. Continuing improvement in the quality of global drinking water supplies alongside the rapid development of antimicrobial resistance predicts the burden and international distribution of S. sonnei will only continue to grow. An effective vaccine against S. sonnei is overdue and may become one of our only weapons against this increasingly dominant and

  18. Shigella Iron Acquisition Systems and their Regulation.

    Science.gov (United States)

    Wei, Yahan; Murphy, Erin R

    2016-01-01

    Survival of Shigella within the host is strictly dependent on the ability of the pathogen to acquire essential nutrients, such as iron. As an innate immune defense against invading pathogens, the level of bio-available iron within the human host is maintained at exceeding low levels, by sequestration of the element within heme and other host iron-binding compounds. In response to sequestration mediated iron limitation, Shigella produce multiple iron-uptake systems that each function to facilitate the utilization of a specific host-associated source of nutrient iron. As a mechanism to balance the essential need for iron and the toxicity of the element when in excess, the production of bacterial iron acquisition systems is tightly regulated by a variety of molecular mechanisms. This review summarizes the current state of knowledge on the iron-uptake systems produced by Shigella species, their distribution within the genus, and the molecular mechanisms that regulate their production.

  19. Riboregulators: Fine-Tuning Virulence in Shigella.

    Science.gov (United States)

    Fris, Megan E; Murphy, Erin R

    2016-01-01

    Within the past several years, RNA-mediated regulation (ribo-regulation) has become increasingly recognized for its importance in controlling critical bacterial processes. Regulatory RNA molecules, or riboregulators, are perpetually responsive to changes within the micro-environment of a bacterium. Notably, several characterized riboregulators control virulence in pathogenic bacteria, as is the case for each riboregulator characterized to date in Shigella. The timing of virulence gene expression and the ability of the pathogen to adapt to rapidly changing environmental conditions is critical to the establishment and progression of infection by Shigella species; ribo-regulators mediate each of these important processes. This mini review will present the current state of knowledge regarding RNA-mediated regulation in Shigella by detailing the characterization and function of each identified riboregulator in these pathogens.

  20. Infección por Campylobacter y Shigella como causa de Diarrea Aguda Infecciosa en niños menores de dos años en el Distrito de la Victoria, Lima-Perú

    Directory of Open Access Journals (Sweden)

    María Perales D

    2002-10-01

    Full Text Available Objetivo: Determinar la frecuencia de Campylobacter y Shigella como agentes etiológicos en diarrea aguda acuosa en niños menores de dos años atendidos en 4 centros de salud del distrito de La Victoria (Lima, Perú Materiales y métodos: en este estudio transversal analítico se realizaron coprocultivos bajo técnica microbiológica estándar a los niños menores de dos años con diarrea aguda acuosa atendidos en 4 centros de salud de La Victoria entre abril y octubre de 2001. Fueron excluidos aquellos niños con disentería y aquellos que habían recibido tratamiento antibiótico previo a la atención. Resultados: se estudiaron un total de 248 casos, de los cuales 48 (19,4% coprocultivos fueron positivos: 33 (13.3% a Campylobacter, 12 (4,8% a Shigella y 3 (1,2% a Salmonella. No se identificaron otros patógenos. Las especies de Shigella identificadas fueron: Shigella flexneri en 9 (75,0% casos y Shigella sonnei en 3 (25,0% La única especie de Campylobacter identificada fue Campylobacter jejuni siendo el biotipo I el más frecuente (84,6% Conclusiones: Campylobacter y Shigella juegan un importante papel como agentes etiológicos causantes de diarrea aguda acuosa en niños menores de dos años.

  1. Intradermal delivery of Shigella IpaB and IpaD type III secretion proteins: kinetics of cell recruitment and antigen uptake, mucosal and systemic immunity, and protection across serotypes.

    Science.gov (United States)

    Heine, Shannon J; Diaz-McNair, Jovita; Andar, Abhay U; Drachenberg, Cinthia B; van de Verg, Lillian; Walker, Richard; Picking, Wendy L; Pasetti, Marcela F

    2014-02-15

    Shigella is one of the leading pathogens contributing to the vast pediatric diarrheal disease burden in low-income countries. No licensed vaccine is available, and the existing candidates are only partially effective and serotype specific. Shigella type III secretion system proteins IpaB and IpaD, which are conserved across Shigella spp., are candidates for a broadly protective, subunit-based vaccine. In this study, we investigated the immunogenicity and protective efficacy of IpaB and IpaD administered intradermally (i.d.) with a double-mutant of the Escherichia coli heat-labile enterotoxin (dmLT) adjuvant using microneedles. Different dosage levels of IpaB and IpaD, with or without dmLT, were tested in mice. Vaccine delivery into the dermis, recruitment of neutrophils, macrophages, dendritic cells, and Langerhans cells, and colocalization of vaccine Ag within skin-activated APC were demonstrated through histology and immunofluorescence microscopy. Ag-loaded neutrophils, macrophages, dendritic cells, and Langerhans cells remained in the tissue at least 1 wk. IpaB, IpaD, and dmLT-specific serum IgG- and IgG-secreting cells were produced following i.d. immunization. The protective efficacy was 70% against Shigella flexneri and 50% against Shigella sonnei. Similar results were obtained when the vaccine was administered intranasally, with the i.d. route requiring 25-40 times lower doses. Distinctively, IgG was detected in mucosal secretions; secretory IgA, as well as mucosal and systemic IgA Ab-secreting cells, were seemingly absent. Vaccine-induced T cells produced IFN-γ, IL-2, TNF-α, IL-17, IL-4, IL-5, and IL-10. These results demonstrate the potential of i.d. vaccination with IpaB and IpaD to prevent Shigella infection and support further studies in humans.

  2. Evaluation of antimicrobial resistance among Salmonella and Shigella isolates in the University Hospital "St. George," Plovdiv, Bulgaria.

    Science.gov (United States)

    Petrov, Michael M; Petrova, Atanaska; Stanimirova, Irina; Mircheva-Topalova, Marina; Koycheva, Lalka; Velcheva, Rayna; Stoycheva-Vartigova, Mariana; Raycheva, Ralitsa; Asseva, Galina; Petrov, Petar; Kardjeva, Velichka; Murdjeva, Marianna

    2017-03-01

    The aim of this work is to study the epidemiology and antimicrobial resistance to the most commonly used antibiotics for the treatment of acute gastroenteritis caused by Salmonella and Shigella at the largest Bulgarian hospital-University Hospital "St. George," Plovdiv-for the period 2009-2013. Two hundred ninety strains were in vitro tested for resistance to 15 antimicrobial agents. The presence of extended-spectrum beta-lactamases (ESBLs) was demonstrated by a variety of specialized tests. For comparison, a collection of 28 strains submitted by the National Reference Laboratory (NRL) "Enteric Infections" at the National Center of Infectious and Parasitic Diseases (NCIPD), Sofia, was also tested for the production of ESBLs. In isolates, phenotypically demonstrated as ESBL producers, polymerase chain reaction (PCR) detection of the genes bla-CTX-M, bla-SHV, and bla-TEM was performed. Among the 290 tested isolates, only two- Salmonella serotype Livingstone and Shigella flexneri-were phenotypically proven to be ESBL producers. Only 4 strains from the collection of 28, submitted from the NRL "Intestinal Infections" in NCIPD, Sofia, were phenotypically confirmed as ESBL producers. The presence of the bla-CTX-M gene was detected in all of the tested strains (4 from NRL, NCIPD, Sofia, and 2 from the University Hospital St. George, Plovdiv), the bla-SHV gene only in strain S. Livingstone from Plovdiv, and the bla-TEM gene in two from Sofia and one (again S. Livingstone) from Plovdiv. In conclusion, Salmonella and Shigella isolates from patients hospitalized at the University Hospital St. George, Plovdiv, with acute gastroenteritis demonstrate good susceptibility to the most commonly used antibiotic agents, including azithromycin.

  3. Enhanced resistance to fluoroquinolones in laboratory-grown mutants & clinical isolates of Shigella due to synergism between efflux pump expression & mutations in quinolone resistance determining region

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    Neelam Taneja

    2015-01-01

    Full Text Available Background & objectives: There is a worldwide emergence of fluoroquinolone resistance in Shigella species. To understand the molecular mechanisms associated with fluoroquinolone resistance, naturally occurring fluoroquinolone-resistant strains and laboratory-induced spontaneous mutants of Shigella spp. were used and the relative contributions of acrAB-tolC efflux pumps, gyrase and topoisomerase target gene mutations towards fluoroquinolone resistance were determined. Methods: Eight Shigella flexneri and six S. dysenteriae clinical isolates were studied. Three consecutive mutants resistant to ciprofloxacin for S. flexneri SFM1 (≥0.25 µg/ml, SFM2 (≥4 µg/ml and SFM3 (≥32 µg/ml were selected in 15 steps from susceptible isolates by serial exposure to increasing concentrations of nalidixic acid and ciprofloxacin. Similarly, two mutants for S. dysenteriae SDM1 (≥0.25 µg/ml and SDM2 (≥4 µg/ml were selected in eight steps. After PCR amplification sequence analyses of gyrase and topoisomerase target genes were performed. Expression of efflux genes acrA, acrB, acrR and tolC was measured using real-time PCR. Results: Mutations were observed in gyrA Ser [83]→Leu, Asp [87]→Asn/Gly, Val [196]→Ala and in parC Phe [93]→Val, Ser [80]→Ile, Asp [101]→Glu and Asp [110]→Glu. Overall, acrA and acrB overexpression was associated with fluoroquinolone resistance ( p0 <0.05; while tolC and acrR expression levels did not. Interpretation & conclusions: Fluoroquinolone resistance in Shigella spp. is the end product of either a single or a combination of mutations in QRDRs and/ or efflux activity. Novel polymorphisms were observed at Val [196]→Ala in gyrA in clinical isolates and Phe [93]→Val, Asp [101]→Glu, Asp [110]→Glu and in parC in majority of laboratory-grown mutants.

  4. Bacteriophage-based Probiotic Preparation for Managing Shigella Infections

    Science.gov (United States)

    2015-04-16

    The preparation (designated “ShigActive”) is a bacteriophage cocktail that specifically targets Shigella spp. (significant diarrhea-causing pathogens...phages lytic for Shigella , and we have developed a murine model in which the in vivo efficacy of our 1. REPORT DATE (DD-MM-YYYY) 4. TITLE AND...10-Apr-2013 Approved for Public Release; Distribution Unlimited Final Report: Bacteriophage-based Probiotic Preparation for Managing Shigella

  5. Study of Shigella Vaccines in Man.

    Science.gov (United States)

    1974-08-15

    and invasive Escherichia coli diarrheal disease, acute non-bacterial gastro- enteritis of adults ( parvovirus ) and choler;-j-For all the above-mentioned...with: 1) Enterotoxigenic E. coli. 2) Invasive E. coli. 3) Parvoviruses . 4) Giardia intestinalis. C. To investigate both the non-specific and specific... attenuated .trains of shigell:i for kise as oral vaccines. Presently we are involved ir, evalua. ion of the ’third gene: ioi " of oral shigella

  6. Shigella sonnei bacteremia in an elderly diabetic patient.

    Science.gov (United States)

    Dronda, F; Parras, F; Martínez, J L; Baquero, F

    1988-06-01

    A case of Shigella sonnei bacteremia in a 65-year-old patient suffering from diabetes mellitus is discussed. The isolated strain had plasmid-mediated serum resistance and excreted aerobactin. The presence of diabetes mellitus as an underlying disease and the production by the Shigella sonnei isolate of factors related to bacterial invasion may have contributed to the bacteremic episode.

  7. Isolation of Salmonella and Shigella species from house flies ...

    African Journals Online (AJOL)

    Salmonella and Shigella species were isolated from House flies (Musca domestica L.) from various sampling sites using selective media. Out of 34 pooled samples Shigella species were isolated in all (100%) of the samples while Salmonella species were isolated in 21 (61.7%) of the samples. The flies pooled from the ...

  8. The infectious hypoxia: occurrence and causes during Shigella infection.

    Science.gov (United States)

    Arena, Ellen T; Tinevez, Jean-Yves; Nigro, Giulia; Sansonetti, Philippe J; Marteyn, Benoit S

    2017-03-01

    Hypoxia is defined as a tissue oxygenation status below physiological needs. During Shigella infection, an infectious hypoxia is induced within foci of infection. In this review, we discuss how Shigella physiology and virulence are modulated and how the main recruited immune cells, the neutrophils, adapt to this environment. Copyright © 2016 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

  9. The genomic signatures of Shigella evolution, adaptation and geographical spread.

    Science.gov (United States)

    The, Hao Chung; Thanh, Duy Pham; Holt, Kathryn E; Thomson, Nicholas R; Baker, Stephen

    2016-04-01

    Shigella spp. are some of the key pathogens responsible for the global burden of diarrhoeal disease. These facultative intracellular bacteria belong to the family Enterobacteriaceae, together with other intestinal pathogens, such as Escherichia coli and Salmonella spp. The genus Shigella comprises four different species, each consisting of several serogroups, all of which show phenotypic similarity, including invasive pathogenicity. DNA sequencing suggests that this similarity results from the convergent evolution of different Shigella spp. founders. Here, we review the evolutionary relationships between Shigella spp. and E . coli, and we highlight how the genomic plasticity of these bacteria and their acquisition of a distinctive virulence plasmid have enabled the development of such highly specialized pathogens. Furthermore, we discuss the insights that genotyping and whole-genome sequencing have provided into the phylogenetics and intercontinental spread of Shigella spp.

  10. Oligomeric states of the Shigella translocator protein IpaB provide structural insights into formation of the type III secretion translocon

    Science.gov (United States)

    Dickenson, Nicholas E; Choudhari, Shyamal P; Adam, Philip R; Kramer, Ryan M; Joshi, Sangeeta B; Middaugh, C Russell; Picking, Wendy L; Picking, William D

    2013-01-01

    The Shigella flexneri Type III secretion system (T3SS) senses contact with human intestinal cells and injects effector proteins that promote pathogen entry as the first step in causing life threatening bacillary dysentery (shigellosis). The Shigella Type III secretion apparatus (T3SA) consists of an anchoring basal body, an exposed needle, and a temporally assembled tip complex. Exposure to environmental small molecules recruits IpaB, the first hydrophobic translocator protein, to the maturing tip complex. IpaB then senses contact with a host cell membrane, forming the translocon pore through which effectors are delivered to the host cytoplasm. Within the bacterium, IpaB exists as a heterodimer with its chaperone IpgC; however, IpaB's structural state following secretion is unknown due to difficulties isolating stable protein. We have overcome this by coexpressing the IpaB/IpgC heterodimer and isolating IpaB by incubating the complex in mild detergents. Interestingly, preparation of IpaB with n-octyl-oligo-oxyethylene (OPOE) results in the assembly of discrete oligomers while purification in N,N-dimethyldodecylamine N-oxide (LDAO) maintains IpaB as a monomer. In this study, we demonstrate that IpaB tetramers penetrate phospholipid membranes to allow a size-dependent release of small molecules, suggesting the formation of discrete pores. Monomeric IpaB also interacts with liposomes but fails to disrupt them. From these and additional findings, we propose that IpaB can exist as a tetramer having inherent flexibility, which allows it to cooperatively interact with and insert into host cell membranes. This event may then lay the foundation for formation of the Shigella T3SS translocon pore. PMID:23456854

  11. Binding Affects the Tertiary and Quaternary Structures of the Shigella Translocator Protein IpaB and its Chaperone IpgC†

    Science.gov (United States)

    Adam, Philip R.; Patil, Mrinalini K.; Dickenson, Nicholas E.; Choudhari, Shyamal; Barta, Michael; Geisbrecht, Brian V.; Picking, Wendy L.; Picking, William D.

    2012-01-01

    Shigella flexneri uses its type III secretion system (T3SS) to promote invasion of human intestinal epithelial cells as the first step in causing shigellosis, a life threatening form of dysentery. The Shigella type III secretion apparatus (T3SA) consists of a basal body that spans the bacterial envelope and an exposed needle that injects effector proteins into target cells. The nascent Shigella T3SA needle is topped with a pentamer of the needle tip protein invasion plasmid antigen D (IpaD). Bile salts trigger recruitment of the first hydrophobic translocator protein, IpaB, to the tip complex where it senses contact with a host membrane. In the bacterial cytoplasm, IpaB exists in a complex with its chaperone IpgC. Several structures of IpgC have been solved and we recently reported the 2.1-Å crystal structure of the N-terminal domain (IpaB74.224) of IpaB. Like IpgC, the IpaB N-terminal domain exists as a homodimer in solution. We now report that when the two are mixed, these homodimers dissociate and form heterodimers having a nanomolar dissociation constant. This is consistent with the equivalent complexes co-purified after being co-expressed in E. coli. Fluorescence data presented here also indicate that the N-terminal domain of IpaB possesses two regions that appear to contribute additively to chaperone binding. It is also likely that the IpaB N terminus adopts an alternative conformation as a result of chaperone binding. The importance of these findings within the functional context of these proteins is discussed. PMID:22497344

  12. Vaccinomics Approach for Designing Potential Peptide Vaccine by Targeting Shigella spp. Serine Protease Autotransporter Subfamily Protein SigA

    Directory of Open Access Journals (Sweden)

    Arafat Rahman Oany

    2017-01-01

    Full Text Available Shigellosis, a bacillary dysentery, is closely associated with diarrhoea in human and causes infection of 165 million people worldwide per year. Casein-degrading serine protease autotransporter of enterobacteriaceae (SPATE subfamily protein SigA, an outer membrane protein, exerts both cytopathic and enterotoxic effects especially cytopathic to human epithelial cell type-2 (HEp-2 and is shown to be highly immunogenic. In the present study, we have tried to impose the vaccinomics approach for designing a common peptide vaccine candidate against the immunogenic SigA of Shigella spp. At first, 44 SigA proteins from different variants of S. flexneri, S. dysenteriae, S. boydii, and S. sonnei were assessed to find the most antigenic protein. We retrieved 12 peptides based on the highest score for human leukocyte antigen (HLA supertypes analysed by NetCTL. Initially, these peptides were assessed for the affinity with MHC class I and class II alleles, and four potential core epitopes VTARAGLGY, FHTVTVNTL, HTTWTLTGY, and IELAGTLTL were selected. From these, FHTVTVNTL and IELAGTLTL peptides were shown to have 100% conservancy. Finally, IELAGTLTL was shown to have the highest population coverage (83.86% among the whole world population. In vivo study of the proposed epitope might contribute to the development of functional and unique widespread vaccine, which might be an operative alleyway to thwart dysentery from the world.

  13. A single-tube screen for Salmonella and Shigella.

    Science.gov (United States)

    Procop, Gary W; Wallace, Jacqueline D; Tuohy, Marion J; Lasalvia, Margret M; Addison, Rachel M; Reller, L Barth

    2008-08-01

    Salmonella and Shigella species are routinely sought in stool specimens submitted for culture. It is a common practice to screen lactose-negative colonies by using triple sugar iron agar, lysine iron agar, and Christensen urea agar to determine if further identification is necessary. We designed and evaluated a novel combination of media, which are layered in a single tube, for screening isolates suspected to possibly represent Salmonella or Shigella. We tested this media combination with 106 Salmonella, 56 Shigella, and 56 other gram-negative bacilli. All Salmonella and Shigella isolates tested were appropriately characterized as possible Salmonella or Shigella by using an algorithm developed for use with this media combination. Similarly, 53 (95%) of 56 other gram-negative bacilli were appropriately screened as non -Salmonella and non -Shigella isolates. This unique media combination provides the most important biochemical reactions needed to screen for Salmonella and Shigella in a single-tube format, which decreases labor by two thirds (ie, 1 tube is inoculated vs 3).

  14. Molecular Mechanisms of Host Cytoskeletal Rearrangements by Shigella Invasins

    Directory of Open Access Journals (Sweden)

    Jun Hyuck Lee

    2014-10-01

    Full Text Available Pathogen-induced reorganization of the host cell cytoskeleton is a common strategy utilized in host cell invasion by many facultative intracellular bacteria, such as Shigella, Listeria, enteroinvasive E. coli and Salmonella. Shigella is an enteroinvasive intracellular pathogen that preferentially infects human epithelial cells and causes bacillary dysentery. Invasion of Shigella into intestinal epithelial cells requires extensive remodeling of the actin cytoskeleton with the aid of pathogenic effector proteins injected into the host cell by the activity of the type III secretion system. These so-called Shigella invasins, including IpaA, IpaC, IpgB1, IpgB2 and IpgD, modulate the actin-regulatory system in a concerted manner to guarantee efficient entry of the bacteria into host cells.

  15. Isolation and Antimicrobial Susceptibility Profile of Shigella and ...

    African Journals Online (AJOL)

    2018-03-01

    Mar 1, 2018 ... species, Vibrio cholera, Yersinia enterocolitica, and Aeromonas species), enteroparasites (Giardia lamblia, Cryptosporidium species and Entamoeba histolytica), and viruses (adenovirus, Norwalk virus, and rotavirus) (5). Among the bacterial causative agents,. Salmonella and Shigella remain the major.

  16. Cytosolic Access of Intracellular Bacterial Pathogens: The Shigella Paradigm.

    Science.gov (United States)

    Mellouk, Nora; Enninga, Jost

    2016-01-01

    Shigella is a Gram-negative bacterial pathogen, which causes bacillary dysentery in humans. A crucial step of Shigella infection is its invasion of epithelial cells. Using a type III secretion system, Shigella injects several bacterial effectors ultimately leading to bacterial internalization within a vacuole. Then, Shigella escapes rapidly from the vacuole, it replicates within the cytosol and spreads from cell-to-cell. The molecular mechanism of vacuolar rupture used by Shigella has been studied in some detail during the recent years and new paradigms are emerging about the underlying molecular events. For decades, bacterial effector proteins were portrayed as main actors inducing vacuolar rupture. This includes the effector/translocators IpaB and IpaC. More recently, this has been challenged and an implication of the host cell in the process of vacuolar rupture has been put forward. This includes the bacterial subversion of host trafficking regulators, such as the Rab GTPase Rab11. The involvement of the host in determining bacterial vacuolar integrity has also been found for other bacterial pathogens, particularly for Salmonella. Here, we will discuss our current view of host factor and pathogen effector implications during Shigella vacuolar rupture and the steps leading to it.

  17. Cytosolic access of intracellular bacterial pathogens: the Shigella paradigm

    Directory of Open Access Journals (Sweden)

    Nora eMellouk

    2016-04-01

    Full Text Available Shigella is a Gram-negative bacterial pathogen, which causes bacillary dysentery in humans. A crucial step of Shigella infection is its invasion of epithelial cells. Using a type III secretion system, Shigella injects several bacterial effectors ultimately leading to bacterial internalization within a vacuole. Then, Shigella escapes rapidly from the vacuole, it replicates within the cytosol and spreads from cell-to-cell. The molecular mechanism of vacuolar rupture used by Shigella has been studied in some detail during the recent years and new paradigms are emerging about the underlying molecular events. For decades, bacterial effector proteins were portrayed as main actors inducing vacuolar rupture. This includes the effector/translocators IpaB and IpaC. More recently, this has been challenged and an implication of the host cell in the process of vacuolar rupture has been put forward. This includes the bacterial subversion of host trafficking regulators, such as the Rab GTPase Rab11. The involvement of the host in determining bacterial vacuolar integrity has also been found for other bacterial pathogens, particularly for Salmonella. Here, we will discuss our current view of host factor and pathogen effector implications during Shigella vacuolar rupture and the steps leading to it.

  18. Attenuated Salmonella enterica Serovar Typhi and Shigella flexneri 2a Strains Mucosally Deliver DNA Vaccines Encoding Measles Virus Hemagglutinin, Inducing Specific Immune Responses and Protection in Cotton Rats

    OpenAIRE

    Pasetti, Marcela F.; Barry, Eileen M.; Losonsky, Genevieve; Singh, Mahender; Medina-Moreno, Sandra M.; Polo, John M.; Ulmer, Jeffrey; Robinson, Harriet; Sztein, Marcelo B.; Levine, Myron M.

    2003-01-01

    Measles remains a leading cause of child mortality in developing countries. Residual maternal measles antibodies and immunologic immaturity dampen immunogenicity of the current vaccine in young infants. Because cotton rat respiratory tract is susceptible to measles virus (MV) replication after intranasal (i.n.) challenge, this model can be used to assess the efficacy of MV vaccines. Pursuing a new measles vaccine strategy that might be effective in young infants, we used attenuated Salmonella...

  19. PERSEPSI MASYARAKAT TERHADAP PENYAKIT SHIGELLA (DISENTRI DI JAKARTA UTARA

    Directory of Open Access Journals (Sweden)

    Siti Sapardiyah Santoso

    2012-09-01

    Full Text Available Penelitian telah dilakukan di Kecamatan Tanjung Priok dan Kecamatan Koja, Jakarta Utara, mengenai perilaku dan sosial budaya dalam penanggulangan penyakit shigella (disentri. Tulisan ini merupakan bagian dari penelitian tersebut. Tujuan penelitian untuk mengetahui persepsi masyarakat Jakarta Utara mengenai penyakit shigella (disentri. Rancangan penelitian cross sectional. Responden berumur diatas 22 tahun laki-laki dan perempuan dipilih secara acak. Pengumpulan data dilakukan dengan wawancara menggunakan koesioner terstruktur kepada 500 responden (250 laki-laki dan 250 wanita. Analisis data menggunakan SPSS. Hasil, menurut responden laki-laki dan perempuan. Masyarakat menganggap serius penyakit shigella (disentri berkisar antara 72,4% - 77,6%. Masyarakat cukup peduli terhadap penyakit tersebut berkisar antara 59,6% - 63,2%. Masyarakat menganggap sakit shigella (disentri lebih berat dari penyakit diare lainnya berkisar antara 67,2% - 71,2%. Kelompok mudah terserang penyakit tersebut adalah balita berkisar antara 85,2% - 86,6%, anak 6 -14 tahun berkisar antara 79,2% -80,8%, bayi 0-1 tahun berkisar antara 79,6% - 86,4%. Lama waktu sembuh yang mengatakan seminggu berkisar antara 54,0% - 55,6%. Penyakit tersebut berpengaruh terhadap sosial ekonomi keluarga dan dianggap serius berkisar antara 52,4% - 53,6%. Biaya bila sakit shigella (disentri ringan maupun berat dianggap mahal berkisar antara 33, 6% - 39,2%. Dari penelitian ini dapat disimpulkan bahwa masyarakat menganggap peduli dan serius terhadap penyakit shigella (disentri karena dianggap lebih parah dari diare lainnya dan pengobatannya dianggap mahal baik shigella (disentri ringan maupun berat.

  20. Changing patterns of drug-resistant Shigella isolates in egypt.

    Science.gov (United States)

    Abd-Elmeged, Ghada M; Khairy, Rasha M; Abo-Eloyoon, Sahar M; Abdelwahab, Sayed F

    2015-06-01

    The emergence of multidrug resistance (MDR) is a serious problem in treating shigellosis. There are limited existing data examining the change in the antimicrobial resistance profile of Shigella in Egypt. We previously reported that 58% of the Shigella isolates in Egypt were resistant to at least one member of the three different antimicrobial groups. This study was performed to determine the antimicrobial resistance profile of Shigella, determine their possible mechanisms of resistance, and compare their resistance profile to those reported 20 years ago. Stool samples were collected from 500 subjects and processed for the isolation and identification of Shigella. The susceptibility of the isolates to 11 different antimicrobials was determined using the disc diffusion method. Of 500 stool cultures, 24 (4.8%) samples were positive for Shigella. There was a high percentage of resistance to ampicillin (88%), tetracycline (83%), and sulfamethoxazole-trimethoprim (75%). Also, there was a moderate percentage of resistance to chloramphenicol (46%), streptomycin (42%), ceftazidime (33%), and cefotaxime (25%). A lower percentage of resistance was recorded for amikacin, nalidixic acid (17% each), and ofloxacin (7%), while no resistance was found to ciprofloxacin (0%). Twenty-one of the isolates (88%) were resistant to at least three different antimicrobial groups (indicating MDR). The average number of antimicrobial agents to which the Shigella isolates were resistant was 4.3±1.4, while it was 3.4±1.5 in the same locality in 1994. These data demonstrate that there is a marked increase in MDR and change in the resistance patterns of Shigella over the past 20 years.

  1. Pathogenesis of Shigella diarrhea: rabbit intestinal cell microvillus membrane binding site for Shigella toxin

    International Nuclear Information System (INIS)

    Fuchs, G.; Mobassaleh, M.; Donohue-Rolfe, A.; Montgomery, R.K.; Grand, R.J.; Keusch, G.T.

    1986-01-01

    This study examined the binding of purified 125 I-labeled shigella toxin to rabbit jejunal microvillus membranes (MVMs). Toxin binding was concentration dependent, saturable, reversible, and specifically inhibited by unlabeled toxin. The calculated number of toxin molecules bound at 4 0 C was 7.9 X 10(10) (3 X 10(10) to 2 X 10(11))/micrograms of MVM protein or 1.2 X 10(6) per enterocyte. Scatchard analysis showed the binding site to be of a single class with an equilibrium association constant, K, of 4.7 X 10(9) M-1 at 4 0 C. Binding was inversely related to the temperature of incubation. A total of 80% of the labeled toxin binding at 4 0 C dissociated from MVM when the temperature was raised to 37 0 C, but reassociated when the temperature was again brought to 4 0 C. There was no structural or functional change of MVM due to toxin as monitored by electron microscopy or assay of MVM sucrase activity. These studies demonstrate a specific binding site for shigella toxin on rabbit MVMs. The physiological relevance of this receptor remains to be determined

  2. The N-terminus of IpaB provides a potential anchor to the Shigella type III secretion system tip complex protein IpaD

    Science.gov (United States)

    Dickenson, Nicholas E.; Arizmendi, Olivia; Patil, Mrinalini K.; Toth, Ronald T.; Middaugh, C. Russell; Picking, William D.; Picking, Wendy L.

    2014-01-01

    The type III secretion system (T3SS) is an essential virulence factor for Shigella flexneri, providing a conduit through which host-altering effectors are injected directly into a host cell to promote uptake. The type III secretion apparatus (T3SA) is comprised of a basal body, external needle, and regulatory tip complex. The nascent needle is a polymer of MxiH capped by a pentamer of invasion plasmid antigen D (IpaD). Exposure to bile salts (e.g. deoxycholate) causes a conformational change in IpaD and promotes recruitment of IpaB to the needle tip. It has been proposed that IpaB senses contact with host cell membranes, recruiting IpaC and inducing full secretion of T3SS effectors. While the steps of T3SA maturation and their external triggers have been identified, details of specific protein interactions and mechanisms have remained difficult to study due to the hydrophobic nature of the IpaB and IpaC translocator proteins. Here we explored the ability for a series of soluble N-terminal IpaB peptides to interact with IpaD. We found that DOC is required for the interaction and that a region of IpaB between residues 11–27 is required for maximum binding, which was confirmed in vivo. Furthermore, intramolecular FRET measurements indicated that movement of the IpaD distal domain away from the protein core accompanied the binding of IpaB11-226. Together these new findings provide important new insight into the interactions and potential mechanisms that define the maturation of the Shigella T3SA needle tip complex and provide a foundation for further studies probing T3SS activation. PMID:24236510

  3. N-terminus of IpaB provides a potential anchor to the Shigella type III secretion system tip complex protein IpaD.

    Science.gov (United States)

    Dickenson, Nicholas E; Arizmendi, Olivia; Patil, Mrinalini K; Toth, Ronald T; Middaugh, C Russell; Picking, William D; Picking, Wendy L

    2013-12-10

    The type III secretion system (T3SS) is an essential virulence factor for Shigella flexneri , providing a conduit through which host-altering effectors are injected directly into a host cell to promote uptake. The type III secretion apparatus (T3SA) is composed of a basal body, external needle, and regulatory tip complex. The nascent needle is a polymer of MxiH capped by a pentamer of invasion plasmid antigen D (IpaD). Exposure to bile salts (e.g., deoxycholate) causes a conformational change in IpaD and promotes recruitment of IpaB to the needle tip. It has been proposed that IpaB senses contact with host cell membranes, recruiting IpaC and inducing full secretion of T3SS effectors. Although the steps of T3SA maturation and their external triggers have been identified, details of specific protein interactions and mechanisms have remained difficult to study because of the hydrophobic nature of the IpaB and IpaC translocator proteins. Here, we explored the ability for a series of soluble N-terminal IpaB peptides to interact with IpaD. We found that DOC is required for the interaction and that a region of IpaB between residues 11-27 is required for maximum binding, which was confirmed in vivo. Furthermore, intramolecular FRET measurements indicated that movement of the IpaD distal domain away from the protein core accompanied the binding of IpaB11-226. Together, these new findings provide important new insight into the interactions and potential mechanisms that define the maturation of the Shigella T3SA needle tip complex and provide a foundation for further studies probing T3SS activation.

  4. The Inside Story of Shigella Invasion of Intestinal Epithelial Cells

    Science.gov (United States)

    Carayol, Nathalie; Tran Van Nhieu, Guy

    2013-01-01

    As opposed to other invasive pathogens that reside into host cells in a parasitic mode, Shigella, the causative agent of bacillary dysentery, invades the colonic mucosa but does not penetrate further to survive into deeper tissues. Instead, Shigella invades, replicates, and disseminates within the colonic mucosa. Bacterial invasion and spreading in intestinal epithelium lead to the elicitation of inflammatory responses responsible for the tissue destruction and shedding in the environment for further infection of other hosts. In this article, we highlight specific features of the Shigella arsenal of virulence determinants injected by a type III secretion apparatus (T3SA) that point to the targeting of intestinal epithelial cells as a discrete route of invasion during the initial event of the infectious process. PMID:24086068

  5. Bioinformatics analyses of Shigella CRISPR structure and spacer classification.

    Science.gov (United States)

    Wang, Pengfei; Zhang, Bing; Duan, Guangcai; Wang, Yingfang; Hong, Lijuan; Wang, Linlin; Guo, Xiangjiao; Xi, Yuanlin; Yang, Haiyan

    2016-03-01

    Clustered regularly interspaced short palindromic repeats (CRISPR) are inheritable genetic elements of a variety of archaea and bacteria and indicative of the bacterial ecological adaptation, conferring acquired immunity against invading foreign nucleic acids. Shigella is an important pathogen for anthroponosis. This study aimed to analyze the features of Shigella CRISPR structure and classify the spacers through bioinformatics approach. Among 107 Shigella, 434 CRISPR structure loci were identified with two to seven loci in different strains. CRISPR-Q1, CRISPR-Q4 and CRISPR-Q5 were widely distributed in Shigella strains. Comparison of the first and last repeats of CRISPR1, CRISPR2 and CRISPR3 revealed several base variants and different stem-loop structures. A total of 259 cas genes were found among these 107 Shigella strains. The cas gene deletions were discovered in 88 strains. However, there is one strain that does not contain cas gene. Intact clusters of cas genes were found in 19 strains. From comprehensive analysis of sequence signature and BLAST and CRISPRTarget score, the 708 spacers were classified into three subtypes: Type I, Type II and Type III. Of them, Type I spacer referred to those linked with one gene segment, Type II spacer linked with two or more different gene segments, and Type III spacer undefined. This study examined the diversity of CRISPR/cas system in Shigella strains, demonstrated the main features of CRISPR structure and spacer classification, which provided critical information for elucidation of the mechanisms of spacer formation and exploration of the role the spacers play in the function of the CRISPR/cas system.

  6. Social buffering and contact transmission: network connections have beneficial and detrimental effects on Shigella infection risk among captive rhesus macaques

    Directory of Open Access Journals (Sweden)

    Krishna Balasubramaniam

    2016-10-01

    Full Text Available In social animals, group living may impact the risk of infectious disease acquisition in two ways. On the one hand, social connectedness puts individuals at greater risk or susceptibility for acquiring enteric pathogens via contact-mediated transmission. Yet conversely, in strongly bonded societies like humans and some nonhuman primates, having close connections and strong social ties of support can also socially buffer individuals against susceptibility or transmissibility of infectious agents. Using social network analyses, we assessed the potentially competing roles of contact-mediated transmission and social buffering on the risk of infection from an enteric bacterial pathogen (Shigella flexneri among captive groups of rhesus macaques (Macaca mulatta. Our results indicate that, within two macaque groups, individuals possessing more direct and especially indirect connections in their grooming and huddling social networks were less susceptible to infection. These results are in sharp contrast to several previous studies that indicate that increased (direct contact-mediated transmission facilitates infectious disease transmission, including our own findings in a third macaque group in which individuals central in their huddling network and/or which initiated more fights were more likely to be infected. In summary, our findings reveal that an individual’s social connections may increase or decrease its chances of acquiring infectious agents. They extend the applicability of the social buffering hypothesis, beyond just stress and immune-function-related health benefits, to the additional health outcome of infectious disease resistance. Finally, we speculate that the circumstances under which social buffering versus contact-mediated transmission may occur could depend on multiple factors, such as living condition, pathogen-specific transmission routes, and/or an overall social context such as a group’s social stability.

  7. Effects of subtherapeutic concentrations of antimicrobials on gene acquisition events in Yersinia, Proteus, Shigella, and Salmonella recipient organisms in isolated ligated intestinal loops of swine.

    Science.gov (United States)

    Brewer, Matt T; Xiong, Nalee; Anderson, Kristi L; Carlson, Steve A

    2013-08-01

    To assess antimicrobial resistance and transfer of virulence genes facilitated by subtherapeutic concentrations of antimicrobials in swine intestines. 20 anesthetized pigs experimentally inoculated with donor and recipient bacteria. 4 recipient pathogenic bacteria (Salmonella enterica serotype Typhimurium, Yersinia enterocolitica, Shigella flexneri, or Proteus mirabilis) were incubated with donor bacteria in the presence of subinhibitory concentrations of 1 of 16 antimicrobials in isolated ligated intestinal loops in swine. Donor Escherichia coli contained transferrable antimicrobial resistance or virulence genes. After coincubations, intestinal contents were removed and assessed for pathogens that acquired new antimicrobial resistance or virulence genes following exposure to the subtherapeutic concentrations of antimicrobials. 3 antimicrobials (apramycin, lincomycin, and neomycin) enhanced transfer of an antimicrobial resistance plasmid from commensal E coli organisms to Yersinia and Proteus organisms, whereas 7 antimicrobials (florfenicol, hygromycin, penicillin G, roxarsone, sulfamethazine, tetracycline, and tylosin) exacerbated transfer of an integron (Salmonella genomic island 1) from Salmonella organisms to Yersinia organisms. Sulfamethazine induced the transfer of Salmonella pathogenicity island 1 from pathogenic to nonpathogenic Salmonella organisms. Six antimicrobials (bacitracin, carbadox, erythromycin, sulfathiazole, tiamulin, and virginiamycin) did not mediate any transfer events. Sulfamethazine was the only antimicrobial implicated in 2 types of transfer events. 10 of 16 antimicrobials at subinhibitory or subtherapeutic concentrations augmented specific antimicrobial resistance or transfer of virulence genes into pathogenic bacteria in isolated intestinal loops in swine. Use of subtherapeutic antimicrobials in animal feed may be associated with unwanted collateral effects.

  8. The host outer membrane proteins OmpA and OmpC are associated with the Shigella phage Sf6 virion

    International Nuclear Information System (INIS)

    Zhao Haiyan; Sequeira, Reuben D.; Galeva, Nadezhda A.; Tang Liang

    2011-01-01

    Assembly of dsDNA bacteriophage is a precisely programmed process. Potential roles of host cell components in phage assembly haven't been well understood. It was previously reported that two unidentified proteins were present in bacteriophage Sf6 virion (Casjens et al, 2004, J.Mol.Biol. 339, 379-394, Fig. 2A). Using tandem mass spectrometry, we have identified the two proteins as outer membrane proteins (OMPs) OmpA and OmpC from its host Shigella flexneri. The transmission electron cryo-microscopy structure of Sf6 shows significant density at specific sites at the phage capsid inner surface. This density fit well with the characteristic beta-barrel domains of OMPs, thus may be due to the two host proteins. Locations of this density suggest a role in Sf6 morphogenesis reminiscent of phage-encoded cementing proteins. These data indicate a new, OMP-related phage:host linkage, adding to previous knowledge that some lambdoid bacteriophage genomes contain OmpC-like genes that express phage-encoded porins in the lysogenic state.

  9. High-resolution structure of the Shigella type-III secretion needle by solid-state NMR and cryo-electron microscopy

    Science.gov (United States)

    Demers, Jean-Philippe; Habenstein, Birgit; Loquet, Antoine; Kumar Vasa, Suresh; Giller, Karin; Becker, Stefan; Baker, David; Lange, Adam; Sgourakis, Nikolaos G.

    2014-09-01

    We introduce a general hybrid approach for determining the structures of supramolecular assemblies. Cryo-electron microscopy (cryo-EM) data define the overall envelope of the assembly and rigid-body orientation of the subunits while solid-state nuclear magnetic resonance (ssNMR) chemical shifts and distance constraints define the local secondary structure, protein fold and inter-subunit interactions. Finally, Rosetta structure calculations provide a general framework to integrate the different sources of structural information. Combining a 7.7-Å cryo-EM density map and 996 ssNMR distance constraints, the structure of the type-III secretion system needle of Shigella flexneri is determined to a precision of 0.4 Å. The calculated structures are cross-validated using an independent data set of 691 ssNMR constraints and scanning transmission electron microscopy measurements. The hybrid model resolves the conformation of the non-conserved N terminus, which occupies a protrusion in the cryo-EM density, and reveals conserved pore residues forming a continuous pattern of electrostatic interactions, thereby suggesting a mechanism for effector protein translocation.

  10. Detection of viable toxigenic Vibrio cholerae and virulent Shigella ...

    African Journals Online (AJOL)

    . cholerae and the invasion plasmid antigen gene (ipaH) of virulent Shigella spp., was performed and the PCR products were visualised by agarose gel electrophoresis. The assay allowed the detection of as few as 1 cfu/100 ml of V. cholerae ...

  11. Antimicrobial resistance of fecal isolates of salmonella and shigella ...

    African Journals Online (AJOL)

    Salmonellosis and Shigellosis coupled with increased levels of multidrug resistances are public health problems, especially in developing countries. This study was aimed at determining the prevalence of fecal Salmonella and Shigella spp and its antimicrobial resistance patterns. A retrospective study was conducted on ...

  12. Shigella Antimicrobial Drug Resistance Mechanisms, 2004-2014.

    Science.gov (United States)

    Nüesch-Inderbinen, Magdalena; Heini, Nicole; Zurfluh, Katrin; Althaus, Denise; Hächler, Herbert; Stephan, Roger

    2016-06-01

    To determine antimicrobial drug resistance mechanisms of Shigella spp., we analyzed 344 isolates collected in Switzerland during 2004-2014. Overall, 78.5% of isolates were multidrug resistant; 10.5% were ciprofloxacin resistant; and 2% harbored mph(A), a plasmid-mediated gene that confers reduced susceptibility to azithromycin, a last-resort antimicrobial agent for shigellosis.

  13. Arginine-dependent acid-resistance pathway in Shigella boydii

    Science.gov (United States)

    Ability to survive the low pH of the human stomach is considered be an important virulent determinant. Acid tolerance of Shigella boydii 18 CDPH, the strain implicated in an outbreak may have played an important role in surviving the acidic food (bean salad). The strain was capable of inducing arg...

  14. Treatment of shigella infections: why sulfamethoxazole-trimethoprim ...

    African Journals Online (AJOL)

    ... and one (1.3%) were Yersinia enterocolitica. Shigella isolates had high resistance to sulfamethoxazole-trimethoprim (97%), tetracycline (83.6%) ampicillin (58.2%) and chloramphenicol (20.9%). The isolates showed low resistance to nalidixic (4.5%) and ciprofloxacin (3.0%) while there was no resistance to ceftriaxone.

  15. Rapid and reliable discrimination between Shigella species and Escherichia coli using MALDI-TOF mass spectrometry.

    Science.gov (United States)

    Paauw, Armand; Jonker, Debby; Roeselers, Guus; Heng, Jonathan M E; Mars-Groenendijk, Roos H; Trip, Hein; Molhoek, E Margo; Jansen, Hugo-Jan; van der Plas, Jan; de Jong, Ad L; Majchrzykiewicz-Koehorst, Joanna A; Speksnijder, Arjen G C L

    2015-01-01

    E. coli-Shigella species are a cryptic group of bacteria in which the Shigella species are distributed within the phylogenetic tree of E. coli. The nomenclature is historically based and the discrimination of these genera developed as a result of the epidemiological need to identify the cause of shigellosis, a severe disease caused by Shigella species. For these reasons, this incorrect classification of shigellae persists to date, and the ability to rapidly characterize E. coli and Shigella species remains highly desirable. Until recently, existing matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) assays used to identify bacteria could not discriminate between E. coli and Shigella species. Here we present a rapid classification method for the E. coli-Shigella phylogroup based on MALDI-TOF MS which is supported by genetic analysis. E. coli and Shigella isolates were collected and genetically characterized by MLVA. A custom reference library for MALDI-TOF MS that represents the genetic diversity of E. coli and Shigella strains was developed. Characterization of E. coli and Shigella species is based on an approach with Biotyper software. Using this reference library it was possible to distinguish between Shigella species and E. coli. Of the 180 isolates tested, 94.4% were correctly classified as E. coli or shigellae. The results of four (2.2%) isolates could not be interpreted and six (3.3%) isolates were classified incorrectly. The custom library extends the existing MALDI-TOF MS method for species determination by enabling rapid and accurate discrimination between Shigella species and E. coli. Copyright © 2015 Elsevier GmbH. All rights reserved.

  16. Antimicrobial Resistance Percentages of Salmonella and Shigella in Seafood Imported to Jordan: Higher Percentages and More Diverse Profiles in Shigella.

    Science.gov (United States)

    Obaidat, Mohammad M; Bani Salman, Alaa E

    2017-03-01

    This study determined the prevalence and antimicrobial resistance of human-specific ( Shigella spp.) and zoonotic ( Salmonella enterica ) foodborne pathogens in internationally traded seafood. Sixty-four Salmonella and 61 Shigella isolates were obtained from 330 imported fresh fish samples from Egypt, Yemen, and India. The pathogens were isolated on selective media, confirmed by PCR, and tested for antimicrobial resistance. Approximately 79 and 98% of the Salmonella and Shigella isolates, respectively, exhibited resistance to at least one antimicrobial, and 8 and 49% exhibited multidrug resistance (resistance to three or more antimicrobial classes). Generally, Salmonella exhibited high resistance to amoxicillin-clavulanic acid, cephalothin, streptomycin, and ampicillin; very low resistance to kanamycin, tetracycline, gentamicin, chloramphenicol, nalidixic acid, sulfamethoxazole-trimethoprim, and ciprofloxacin; and no resistance to ceftriaxone. Meanwhile, Shigella spp. exhibited high resistance to tetracycline, amoxicillin-clavulanic acid, cephalothin, streptomycin, and ampicillin; low resistance to kanamycin, nalidixic acid, sulfamethoxazole-trimethoprim, and ceftriaxone; and very low resistance to gentamicin and ciprofloxacin. Salmonella isolates exhibited 14 resistance profiles, Shigella isolates 42. This study is novel in showing that a human-specific pathogen has higher antimicrobial resistance percentages and more diverse profiles than a zoonotic pathogen. Thus, the impact of antimicrobial use in humans is as significant as, if not more significant than, it is in animals in spreading antibiotic resistance through food. This study also demonstrates that locally derived antimicrobial resistance can spread and pose a public health risk worldwide through seafood trade and that high resistance would make a possible outbreak difficult to control. So, capacity building and monitoring harvest water areas are encouraged in fish producing countries.

  17. Outer membrane proteins analysis of Shigella sonnei and evaluation of their antigenicity in Shigella infected individuals.

    Directory of Open Access Journals (Sweden)

    Hemavathy Harikrishnan

    Full Text Available Bacillary dysentery caused by infection with Shigella spp. remains as serious and common health problem throughout the world. It is a highly multi drug resistant organism and rarely identified from the patient at the early stage of infection. S. sonnei is the most frequently isolated species causing shigellosis in industrialized countries. The antigenicity of outer membrane protein of this pathogen expressed during human infection has not been identified to date. We have studied the antigenic outer membrane proteins expressed by S. sonnei, with the aim of identifying presence of specific IgA and IgG in human serum against the candidate protein biomarkers. Three antigenic OMPs sized 33.3, 43.8 and 100.3 kDa were uniquely recognized by IgA and IgG from patients with S. sonnei infection, and did not cross-react with sera from patients with other types of infection. The antigenic proteome data generated in this study are a first for OMPs of S. sonnei, and they provide important insights of human immune responses. Furthermore, numerous prime candidate proteins were identified which will aid the development of new diagnostic tools for the detection of S. sonnei.

  18. Horizontal antimicrobial resistance transfer drives epidemics of multiple Shigella species.

    Science.gov (United States)

    Baker, Kate S; Dallman, Timothy J; Field, Nigel; Childs, Tristan; Mitchell, Holly; Day, Martin; Weill, François-Xavier; Lefèvre, Sophie; Tourdjman, Mathieu; Hughes, Gwenda; Jenkins, Claire; Thomson, Nicholas

    2018-04-13

    Horizontal gene transfer has played a role in developing the global public health crisis of antimicrobial resistance (AMR). However, the dynamics of AMR transfer through bacterial populations and its direct impact on human disease is poorly elucidated. Here, we study parallel epidemic emergences of multiple Shigella species, a priority AMR organism, in men who have sex with men to gain insight into AMR emergence and spread. Using genomic epidemiology, we show that repeated horizontal transfer of a single AMR plasmid among Shigella enhanced existing and facilitated new epidemics. These epidemic patterns contrasted with slighter, slower increases in disease caused by organisms with vertically inherited (chromosomally encoded) AMR. This demonstrates that horizontal transfer of AMR directly affects epidemiological outcomes of globally important AMR pathogens and highlights the need for integration of genomic analyses into all areas of AMR research, surveillance and management.

  19. Sensitive seminested PCR method for the detection of Shigella in spiked environmental water samples

    CSIR Research Space (South Africa)

    Theron, J

    2001-03-01

    Full Text Available to shigellae and EIEC and implicated in virulent functions, is present in multiple copies on the invasion plasmid and the chromosome (Venkatesan et al., 1989, 1991; Hartman et al., 1990; Hale, 1991). The standard procedure for Shigella spp. detection is based... on isolation of Shigella by selective culture media followed by identi?cation by biochemical tests and agglutination assays (Frankel et al., 1989; June et al., 1993). This process may take 48?72 h or even longer to obtain results. Since shigellae are very...

  20. How Shigella Utilizes Ca(2+) Jagged Edge Signals during Invasion of Epithelial Cells.

    Science.gov (United States)

    Bonnet, Mariette; Tran Van Nhieu, Guy

    2016-01-01

    Shigella, the causative agent of bacillary dysentery invades intestinal epithelial cells using a type III secretion system (T3SS). Through the injection of type III effectors, Shigella manipulates the actin cytoskeleton to induce its internalization in epithelial cells. At early invasion stages, Shigella induces atypical Ca(2+) responses confined at entry sites allowing local cytoskeletal remodeling for bacteria engulfment. Global Ca(2+) increase in the cell triggers the opening of connexin hemichannels at the plasma membrane that releases ATP in the extracellular milieu, favoring Shigella invasion and spreading through purinergic receptor signaling. During intracellular replication, Shigella regulates inflammatory and death pathways to disseminate within the epithelium. At later stages of infection, Shigella downregulates hemichannel opening and the release of extracellular ATP to dampen inflammatory signals. To avoid premature cell death, Shigella activates cell survival by upregulating the PI3K/Akt pathway and downregulating the levels of p53. Furthermore, Shigella interferes with pro-apoptotic caspases, and orients infected cells toward a slow necrotic cell death linked to mitochondrial Ca(2+) overload. In this review, we will focus on the role of Ca(2+) responses and their regulation by Shigella during the different stages of bacterial infection.

  1. How Shigella Utilizes Ca2+ Jagged Edge Signals during Invasion of Epithelial Cells

    Science.gov (United States)

    Bonnet, Mariette; Tran Van Nhieu, Guy

    2016-01-01

    Shigella, the causative agent of bacillary dysentery invades intestinal epithelial cells using a type III secretion system (T3SS). Through the injection of type III effectors, Shigella manipulates the actin cytoskeleton to induce its internalization in epithelial cells. At early invasion stages, Shigella induces atypical Ca2+ responses confined at entry sites allowing local cytoskeletal remodeling for bacteria engulfment. Global Ca2+ increase in the cell triggers the opening of connexin hemichannels at the plasma membrane that releases ATP in the extracellular milieu, favoring Shigella invasion and spreading through purinergic receptor signaling. During intracellular replication, Shigella regulates inflammatory and death pathways to disseminate within the epithelium. At later stages of infection, Shigella downregulates hemichannel opening and the release of extracellular ATP to dampen inflammatory signals. To avoid premature cell death, Shigella activates cell survival by upregulating the PI3K/Akt pathway and downregulating the levels of p53. Furthermore, Shigella interferes with pro-apoptotic caspases, and orients infected cells toward a slow necrotic cell death linked to mitochondrial Ca2+ overload. In this review, we will focus on the role of Ca2+ responses and their regulation by Shigella during the different stages of bacterial infection. PMID:26904514

  2. How Shigella utilizes Ca2+ jagged edge signals during invasion of epithelial cells

    Directory of Open Access Journals (Sweden)

    Mariette eBonnet

    2016-02-01

    Full Text Available Shigella, the causative agent of bacillary dysentery invades intestinal epithelial cells using a type III secretion system (T3SS. Through the injection of type III effectors, Shigella manipulates the actin cytoskeleton to induce its internalization in epithelial cells. At early invasion stages, Shigella induces atypical Ca2+ responses confined at entry sites allowing local cytoskeletal remodeling for bacteria engulfment. Global Ca2+ increase in the cell triggers the opening of connexin hemichannels at the plasma membrane that releases ATP in the extracellular milieu, favoring Shigella invasion and spreading through purinergic receptor signaling. During intracellular replication, Shigella regulates inflammatory and death pathways to disseminate within the epithelium. At later stages of infection, Shigella downregulates hemichannel opening and the release of extracellular ATP to dampen inflammatory signals. To avoid premature cell death, Shigella activates cell survival by upregulating the PI3K/Akt pathway and downregulating the levels of p53. Furthermore, Shigella interferes with pro-apoptotic caspases, and orients infected cells towards a slow necrotic cell death linked to mitochondrial Ca2+ overload. In this review, we will focus on the role of Ca2+ responses and their regulation by Shigella during the different stages of bacterial infection.

  3. Symptomatic Shigella sonnei urinary tract infection in pregnancy.

    Science.gov (United States)

    Baka, S; Spathi, A; Tsouma, I; Kouskouni, E

    2013-01-01

    This report describes a case of urinary tract infection (UTI) due to Shigella sonnei during pregnancy. A 31-year-old pregnant woman was admitted complaining of left-flank tenderness, dysuria, and fever. Following examination, significant laboratory data were collected including increased leukocyte count (10,800/ul with 86% neutrophils) and C-reactive protein (9.6 mg/dl). Urinalysis revealed 30 to 50 leukocytes per high power field while from the quantitative urine culture Shigella sonnei was recovered after 24 h incubation at 37 degrees C. After a two-week course with 750 mg cefuroxime every 8 h, the patient experienced gradual resolution of all symptoms and urinary cultures were negative two weeks and one month, respectively, after completing the therapy. The gestational course was uneventful and the patient delivered a healthy baby girl at term. Shigella sonnei can be responsible for UTI during pregnancy even when no predisposing factors or an apparent source of infection can be identified.

  4. Fractionation and purification of DNA methylases of Shigella sonnei

    International Nuclear Information System (INIS)

    Suchkov, S.V.; Nikol'skaya, I.I.; Debov, S.S.

    1986-01-01

    A comparative study was made of the possibilities of various types of column chromatography and isoelectrofocusing for the analysis of the set of DNA methylases of the strains Shigella sonnei 47. On the basic of cation-exchange chromatography, a simple, rapid, and convenient method has been developed for the production of a highly active summary preparations of DNA methylases. It has been shown that affinity chromatography on heparin-Sepharose provides for the separation of methylases according to the characteristic of specificity for the nitrogen base. The presence of six individuals enzymes of DNA methylation, differing in value of the isoelectric point, was demonstrated in Shigella sonnei 47 cells by the IEF* method. Increased ability of the DNA methylases of Shigella sonnei 47 for nonspecific aggregation during the process of fractionation was demonstrated, which makes the use of column chromatography unsuitable for the isolation and purification of individual methylating enzymes of the investigated strain. The advantages of the IEF method, as well as its potentialities from the standpoint of studying various molecular forms of site-specific enzymes, are discussed

  5. Shigella subverts the host recycling compartment to rupture its vacuole.

    Science.gov (United States)

    Mellouk, Nora; Weiner, Allon; Aulner, Nathalie; Schmitt, Christine; Elbaum, Michael; Shorte, Spencer L; Danckaert, Anne; Enninga, Jost

    2014-10-08

    Shigella enters epithlial cells via internalization into a vacuole. Subsequent vacuolar membrane rupture allows bacterial escape into the cytosol for replication and cell-to-cell spread. Bacterial effectors such as IpgD, a PI(4,5)P2 phosphatase that generates PI(5)P and alters host actin, facilitate this internalization. Here, we identify host proteins involved in Shigella uptake and vacuolar membrane rupture by high-content siRNA screening and subsequently focus on Rab11, a constituent of the recycling compartment. Rab11-positive vesicles are recruited to the invasion site before vacuolar rupture, and Rab11 knockdown dramatically decreases vacuolar membrane rupture. Additionally, Rab11 recruitment is absent and vacuolar rupture is delayed in the ipgD mutant that does not dephosphorylate PI(4,5)P₂ into PI(5)P. Ultrastructural analyses of Rab11-positive vesicles further reveal that ipgD mutant-containing vacuoles become confined in actin structures that likely contribute to delayed vacular rupture. These findings provide insight into the underlying molecular mechanism of vacuole progression and rupture during Shigella invasion. Copyright © 2014 Elsevier Inc. All rights reserved.

  6. Temperature Regulation of Shigella Virulence: Identification of Temperature-Regulated Shigella Invasion Genes by the Isolation of inv::lacZ Operon Fusions and the Characterization of the Virulence Gene Regulator virR

    Science.gov (United States)

    1991-04-10

    conserved in virulent strains of Shigella and EIEC. Evaluation of the serum Immune response to Shigella proteins in Rhesus monkeys and humans revealed...sera from both humans and monkeys following a Shigella infection (Hale et al. , 1985; Oaks et al., 1986). Moreover, Tn5 insertions In various...Microbiology, Washington, D.C. 108. Oaks, E, V,, T, L. Hale, and S. B. Formal. 1986. Serum Immune response to Shigella protein antigens In Rhesus monkeys

  7. Molecular characterization of Shigella spp. from patients in Gabon 2011-2013

    NARCIS (Netherlands)

    Schaumburg, Frieder; Alabi, Abraham S.; Kaba, Harry; Lell, Bertrand; Becker, Karsten; Grobusch, Martin P.; Kremsner, Peter G.; Mellmann, Alexander

    2015-01-01

    Shigella spp. dysentery is widespread in developing countries; the incidence is particularly high in children between 1-2 years of age. In sub-Saharan Africa, there is a paucity of epidemiological data on Shigella spp., with possible negative consequences for recognition and correct treatment choice

  8. Modulation of Caenorhabditis elegans immune response and modification of Shigella endotoxin upon interaction.

    Science.gov (United States)

    Kesika, Periyanaina; Prasanth, Mani Iyer; Balamurugan, Krishnaswamy

    2015-04-01

    To analyze the pathogenesis at both physiological and molecular level using the model organism, Caenorhabditis elegans at different developmental stages in response to Shigella spp. and its pathogen associated molecular patterns such as lipopolysaccharide. The solid plate and liquid culture-based infection assays revealed that Shigella spp. infects C. elegans and had an impact on the brood size and pharyngeal pumping rate. LPS of Shigella spp. was toxic to C. elegans. qPCR analysis revealed that host innate immune genes have been modulated upon Shigella spp. infections and its LPS challenges. Non-destructive analysis was performed to kinetically assess the alterations in LPS during interaction of Shigella spp. with C. elegans. The modulation of innate immune genes attributed the surrendering of host immune system to Shigella spp. by favoring the infection. LPS appeared to have a major role in Shigella-mediated pathogenesis and Shigella employs a tactic behavior of modifying its LPS content to escape from the recognition of host immune system. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Rapid and reliable discrimination between Shigella species and Escherichia coli using MALDI-TOF mass spectrometry

    NARCIS (Netherlands)

    Paauw, A.; Jonker, D.; Roeselers, G.; Heng, J.M.E.; Mars-Groenendijk, R.H.; Trip, H.; Molhoek, E.M.; Jansen, H.J.; Plas, J. van der; Jong, A.L. de; Majchrzykiewicz-Koehorst, J.A.; Speksnijder, A.G.C.L.

    2015-01-01

    E. coli-. Shigella species are a cryptic group of bacteria in which the Shigella species are distributed within the phylogenetic tree of E. coli. The nomenclature is historically based and the discrimination of these genera developed as a result of the epidemiological need to identify the cause of

  10. Global burden of Shigella infections : implications for vaccine development and implementation of control strategies

    NARCIS (Netherlands)

    Kotloff, KL; Winickoff, JP; Ivanoff, B; Clemens, JD; Swerdlow, DL; Sansonetti, PJ; Adak, GK; Levine, MM

    1999-01-01

    Few studies provide data on the global morbidity and mortality caused by infection with Shigella spp.; such estimates are needed, however, to plan strategies of prevention and treatment. Here we report the results of a review of the literature published between 1966 and 1997 on Shigella infection.

  11. Increasing Antibiotic Resistance in Shigella spp. from Infected New York City Residents, New York, USA.

    Science.gov (United States)

    Murray, Kenya; Reddy, Vasudha; Kornblum, John S; Waechter, HaeNa; Chicaiza, Ludwin F; Rubinstein, Inessa; Balter, Sharon; Greene, Sharon K; Braunstein, Sarah L; Rakeman, Jennifer L; Dentinger, Catherine M

    2017-02-01

    Approximately 20% of Shigella isolates tested in New York City, New York, USA, during 2013-2015 displayed decreased azithromycin susceptibility. Case-patients were older and more frequently male and HIV infected than those with azithromycin-susceptible Shigella infection; 90% identified as men who have sex with men. Clinical interpretation guidelines for azithromycin resistance and outcome studies are needed.

  12. Shigella infection of intestinal epithelium and circumvention of the host innate defense system.

    Science.gov (United States)

    Ashida, Hiroshi; Ogawa, Michinaga; Mimuro, Hitomi; Sasakawa, Chihiro

    2009-01-01

    Shigella, Gram-negative bacteria closely related to Escherichia coli, are highly adapted human pathogens that cause bacillary dysentery. Although Shigella have neither adherence factors nor flagella required for attaching or accessing the intestinal epithelium, Shigella are capable of colonizing the intestinal epithelium by exploiting epithelial-cell functions and circumventing the host innate immune response. During Shigella infection, they deliver many numbers of effectors through the type III secretion system into the surrounding space and directly into the host-cell cytoplasm. The effectors play pivotal roles from the onset of bacterial infection through to the establishment of the colonization of the intestinal epithelium, such as bacterial invasion, intracellular survival, subversion of the host immune defense response, and maintenance of the infectious foothold. These examples suggest that Shigella have evolved highly sophisticated infectious and intracellular strategies to establish replicative niches in the intestinal epithelium.

  13. Molecular diagnosis of non-serotypeable Shigella spp.: problems and prospects.

    Science.gov (United States)

    Muthuirulandi Sethuvel, Dhiviya Prabaa; Devanga Ragupathi, Naveen Kumar; Anandan, Shalini; Walia, Kamini; Veeraraghavan, Balaji

    2017-02-01

    It is not always possible to identify Shigella serogroups/serotypes by biochemical properties alone. Specific identification requires serotyping. Occasionally, isolates that resemble Shigella spp. biochemically, but are non-agglutinable with available antisera, have been observed. Several mechanisms have been reported to limit the efficiency of the serotyping assay. Serotype conversion is a major mechanism in Shigella spp. to escape protective host immune responses. This easy conversion through significant modification of the O-antigen backbone results in different serotypes, which makes laboratory identification difficult. Furthermore, members of the family Enterobacteriaceae are closely related and there is antigenic cross-over (intra- and inter-specific cross-reaction) which affects the agglutination reaction. The performance of the available methods for identification of non-serotypeable Shigella is discussed here, and reveals them to be non-reliable. This shows a need for an alternative method for identification and typing of Shigella spp.

  14. A clinically parameterized mathematical model of Shigella immunity to inform vaccine design.

    Directory of Open Access Journals (Sweden)

    Courtney L Davis

    Full Text Available We refine and clinically parameterize a mathematical model of the humoral immune response against Shigella, a diarrheal bacteria that infects 80-165 million people and kills an estimated 600,000 people worldwide each year. Using Latin hypercube sampling and Monte Carlo simulations for parameter estimation, we fit our model to human immune data from two Shigella EcSf2a-2 vaccine trials and a rechallenge study in which antibody and B-cell responses against Shigella's lipopolysaccharide (LPS and O-membrane proteins (OMP were recorded. The clinically grounded model is used to mathematically investigate which key immune mechanisms and bacterial targets confer immunity against Shigella and to predict which humoral immune components should be elicited to create a protective vaccine against Shigella. The model offers insight into why the EcSf2a-2 vaccine had low efficacy and demonstrates that at a group level a humoral immune response induced by EcSf2a-2 vaccine or wild-type challenge against Shigella's LPS or OMP does not appear sufficient for protection. That is, the model predicts an uncontrolled infection of gut epithelial cells that is present across all best-fit model parameterizations when fit to EcSf2a-2 vaccine or wild-type challenge data. Using sensitivity analysis, we explore which model parameter values must be altered to prevent the destructive epithelial invasion by Shigella bacteria and identify four key parameter groups as potential vaccine targets or immune correlates: 1 the rate that Shigella migrates into the lamina propria or epithelium, 2 the rate that memory B cells (BM differentiate into antibody-secreting cells (ASC, 3 the rate at which antibodies are produced by activated ASC, and 4 the Shigella-specific BM carrying capacity. This paper underscores the need for a multifaceted approach in ongoing efforts to design an effective Shigella vaccine.

  15. A clinically parameterized mathematical model of Shigella immunity to inform vaccine design.

    Science.gov (United States)

    Davis, Courtney L; Wahid, Rezwanul; Toapanta, Franklin R; Simon, Jakub K; Sztein, Marcelo B

    2018-01-01

    We refine and clinically parameterize a mathematical model of the humoral immune response against Shigella, a diarrheal bacteria that infects 80-165 million people and kills an estimated 600,000 people worldwide each year. Using Latin hypercube sampling and Monte Carlo simulations for parameter estimation, we fit our model to human immune data from two Shigella EcSf2a-2 vaccine trials and a rechallenge study in which antibody and B-cell responses against Shigella's lipopolysaccharide (LPS) and O-membrane proteins (OMP) were recorded. The clinically grounded model is used to mathematically investigate which key immune mechanisms and bacterial targets confer immunity against Shigella and to predict which humoral immune components should be elicited to create a protective vaccine against Shigella. The model offers insight into why the EcSf2a-2 vaccine had low efficacy and demonstrates that at a group level a humoral immune response induced by EcSf2a-2 vaccine or wild-type challenge against Shigella's LPS or OMP does not appear sufficient for protection. That is, the model predicts an uncontrolled infection of gut epithelial cells that is present across all best-fit model parameterizations when fit to EcSf2a-2 vaccine or wild-type challenge data. Using sensitivity analysis, we explore which model parameter values must be altered to prevent the destructive epithelial invasion by Shigella bacteria and identify four key parameter groups as potential vaccine targets or immune correlates: 1) the rate that Shigella migrates into the lamina propria or epithelium, 2) the rate that memory B cells (BM) differentiate into antibody-secreting cells (ASC), 3) the rate at which antibodies are produced by activated ASC, and 4) the Shigella-specific BM carrying capacity. This paper underscores the need for a multifaceted approach in ongoing efforts to design an effective Shigella vaccine.

  16. Virulence variations in Shigella and enteroinvasive Escherichia coli using the Caenorhabditis elegans model.

    Science.gov (United States)

    Fung, Crystal Ching; Octavia, Sophie; Mooney, Anne-Marie; Lan, Ruiting

    2015-01-01

    Shigella species and enteroinvasive Escherichia coli (EIEC) belong to the same species genetically, with remarkable phenotypic and genomic similarities. Shigella is the main cause of bacillary dysentery with around 160 million annual cases, while EIEC generally induces a milder disease compared to Shigella. This study aimed to determine virulence variations between Shigella and EIEC using the nematode Caenorhabditis elegans as a model host. Caenorhabditis elegans killing- and bacterial colonization assays were performed to examine the potential difference in virulence between Shigella and EIEC strains. Statistically significant difference in the survival rates of nematodes was demonstrated, with Shigella causing death at 88.24 ± 1.20% and EIEC at 94.37 ± 0.70%. The intestinal load of bacteria in the nematodes was found to be 7.65 × 10(4) ± 8.83 × 10(3) and 2.92 × 10(4) ± 6.26 × 10(3) CFU ml(-1) per nematode for Shigella and EIEC, respectively. Shigella dysenteriae serotype 1 which carries the Shiga toxin showed the lowest nematode survival rate at 82.6 ± 3.97% and highest bacterial colonization of 1.75 × 10(5) ± 8.17 × 10(4) CFU ml(-1), whereas a virulence plasmid-negative Shigella strain demonstrated 100 ± 0% nematode survival and lowest bacterial accumulation of 1.02 × 10(4) ± 7.23 × 10(2) CFU ml(-1). This study demonstrates C. elegans as an effective model for examining and comparing Shigella and EIEC virulence variation. © FEMS 2014. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  17. Gene decay in Shigella as an incipient stage of host-adaptation.

    Directory of Open Access Journals (Sweden)

    Ye Feng

    Full Text Available BACKGROUND: Many facultative bacterial pathogens have undergone extensive gene decay processes, possibly due to lack of selection pressure during evolutionary conversion from free-living to intracellular lifestyle. Shigella, the causative agents of human shigellosis, have arisen from different E. coli-like ancestors independently by convergent paths. As these bacteria all have lost large numbers of genes by mutation or deletion, they can be used as ideal models for systematically studying the process of gene function loss in different bacteria living under similar selection pressures. METHODOLOGIES/PRINCIPAL FINDINGS: We compared the sequenced Shigella genomes and re-defined decayed genes (pseudogenes plus deleted genes in these bacteria. Altogether, 85 genes are commonly decayed in the five analyzed Shigella strains and 1456 genes are decayed in at least one Shigella strain. Genes coding for carbon utilization, cell motility, transporter or membrane proteins are prone to be inactivated. Decayed genes tend to concentrate in certain operons rather than distribute averagely across the whole genome. Genes in the decayed operon accumulated more non-synonymous mutations than the rest genes and meanwhile have lower expression levels. CONCLUSIONS: Different Shigella lineages underwent convergent gene decay processes, and inactivation of one gene would lead to a lesser selection pressure for the other genes in the same operon. The pool of superfluous genes for Shigella may contain at least two thousand genes and the gene decay processes may still continue in Shigella until a minimum genome harboring only essential genes is reached.

  18. Shigella sonnei and hemolytic uremic syndrome: A case report and literature review

    Directory of Open Access Journals (Sweden)

    Casey Adams

    2017-01-01

    Full Text Available Hemolytic uremic syndrome (HUS is a well-described process that is known to cause severe renal dysfunction, thrombocytopenia, and anemia. HUS is typically associated with toxins (shiga-like and shigella toxin found in strains of E. coli and Shigella spp [1–3]. We present a case of a 27 year-old man with jaundice, thrombocytopenia, and renal dysfunction who was found to have HUS in the setting of Shigella sonnei infection. Outside of developing countries, cases of HUS related to S. sonnei are largely unreported.

  19. Cellular Aspects of Shigella Pathogenesis: Focus on the Manipulation of Host Cell Processes.

    Science.gov (United States)

    Killackey, Samuel A; Sorbara, Matthew T; Girardin, Stephen E

    2016-01-01

    Shigella is a Gram-negative bacterium that is responsible for shigellosis. Over the years, the study of Shigella has provided a greater understanding of how the host responds to bacterial infection, and how bacteria have evolved to effectively counter the host defenses. In this review, we provide an update on some of the most recent advances in our understanding of pivotal processes associated with Shigella infection, including the invasion into host cells, the metabolic changes that occur within the bacterium and the infected cell, cell-to-cell spread mechanisms, autophagy and membrane trafficking, inflammatory signaling and cell death. This recent progress sheds a new light into the mechanisms underlying Shigella pathogenesis, and also more generally provides deeper understanding of the complex interplay between host cells and bacterial pathogens in general.

  20. Risk factors for secondary transmission of Shigella infection within households: implications for current prevention policy

    NARCIS (Netherlands)

    Boveé, Lian; Whelan, Jane; Sonder, Gerard J. B.; van Dam, Alje P.; van den Hoek, Anneke

    2012-01-01

    Background: Internationally, guidelines to prevent secondary transmission of Shigella infection vary widely. Cases, their contacts with diarrhoea, and those in certain occupational groups are frequently excluded from work, school, or daycare. In the Netherlands, all contacts attending pre-school

  1. Shigella Infections in Household Contacts of Pediatric Shigellosis Patients in Rural Bangladesh.

    Science.gov (United States)

    George, Christine Marie; Ahmed, Shahnawaz; Talukder, Kaisar A; Azmi, Ishrat J; Perin, Jamie; Sack, R Bradley; Sack, David A; Stine, O Colin; Oldja, Lauren; Shahnaij, Mohammad; Chakraborty, Subhra; Parvin, Tahmina; Bhuyian, Sazzadul Islam; Bouwer, Edward; Zhang, Xiaotong; Hasan, Trisheeta N; Luna, Sharmin J; Akter, Fatema; Faruque, Abu S G

    2015-11-01

    To examine rates of Shigella infections in household contacts of pediatric shigellosis patients, we followed contacts and controls prospectively for 1 week after the index patient obtained care. Household contacts of patients were 44 times more likely to develop a Shigella infection than were control contacts (odds ratio 44.7, 95% CI 5.5-361.6); 29 (94%) household contacts of shigellosis patients were infected with the same species and serotype as the index patient's. Pulsed-field gel electrophoresis showed that 14 (88%) of 16 with infected contacts had strains that were indistinguishable from or closely related to the index patient's strain. Latrine area fly counts were higher in patient households compared with control households, and 2 patient household water samples were positive for Shigella. We show high susceptibility of household contacts of shigellosis patients to Shigella infections and found environmental risk factors to be targeted in future interventions.

  2. International foodborne outbreak of Shigella sonnei infection in airline passengers.

    Science.gov (United States)

    Gaynor, K; Park, S Y; Kanenaka, R; Colindres, R; Mintz, E; Ram, P K; Kitsutani, P; Nakata, M; Wedel, S; Boxrud, D; Jennings, D; Yoshida, H; Tosaka, N; He, H; Ching-Lee, M; Effler, P V

    2009-03-01

    During 22-24 August 2004, an outbreak of Shigella sonnei infection affected air travellers who departed from Hawaii. Forty-seven passengers with culture-confirmed shigellosis and 116 probable cases who travelled on 12 flights dispersed to Japan, Australia, 22 US states, and American Samoa. All flights were served by one caterer. Pulsed-field gel electrophoresis of all 29 S. sonnei isolates yielded patterns that matched within one band. Food histories and menu reviews identified raw carrot served onboard as the likely vehicle of infection. Attack rates for diarrhoea on three surveyed flights with confirmed cases were 54% (110/204), 32% (20/63), and 12% (8/67). A total of 2700 meals were served on flights with confirmed cases; using attack rates observed on surveyed flights, we estimated that 300-1500 passengers were infected. This outbreak illustrates the risk of rapid, global spread of illness from a point-source at a major airline hub.

  3. Role of the SRRz/Rz1 lambdoid lysis cassette in the pathoadaptive evolution of Shigella.

    Science.gov (United States)

    Leuzzi, Adriano; Grossi, Milena; Di Martino, Maria Letizia; Pasqua, Martina; Micheli, Gioacchino; Colonna, Bianca; Prosseda, Gianni

    2017-06-01

    Shigella, the etiological agent of bacillary dysentery (shigellosis), is a highly adapted human pathogen. It evolved from an innocuous ancestor resembling the Escherichia coli strain by gain and loss of genes and functions. While the gain process concerns the acquisition of the genetic determinants of virulence, the loss is related to the adaptation of the genome to the new pathogenic status and occurs by pathoadaptive mutation of antivirulence genes. In this study, we highlight that the SRRz/Rz 1 lambdoid lysis cassette, even though stably adopted in E. coli K12 by virtue of its beneficial effect on cell physiology, has undergone a significant decay in Shigella. Moreover, we show the antivirulence nature of the SRRz/Rz 1 lysis cassette in Shigella. In fact, by restoring the SRRz/Rz 1 expression in this pathogen, we observe an increased release of peptidoglycan fragments, causing an unbalance in the fine control exerted by Shigella on host innate immunity and a mitigation of its virulence. This strongly affects the virulence of Shigella and allows to consider the loss of SRRz/Rz 1 lysis cassette as another pathoadaptive event in the life of Shigella. Copyright © 2017 Elsevier GmbH. All rights reserved.

  4. UV-C Adaptation of Shigella: Morphological, Outer Membrane Proteins, Secreted Proteins, and Lipopolysaccharides Effects.

    Science.gov (United States)

    Chourabi, Kalthoum; Campoy, Susana; Rodriguez, Jesus A; Kloula, Salma; Landoulsi, Ahmed; Chatti, Abdelwaheb

    2017-11-01

    Water UV disinfection remains extremely important, particularly in developing countries where drinking and reclaimed crop irrigation water may spread devastating infectious diseases. Enteric bacterial pathogens, among which Shigella, are possible contaminants of drinking and bathing water and foods. To study the effect of UV light on Shigella, four strains were exposed to different doses in a laboratory-made irradiation device, given that the ultraviolet radiation degree of inactivation is directly related to the UV dose applied to water. Our results showed that the UV-C rays are effective against all the tested Shigella strains. However, UV-C doses appeared as determinant factors for Shigella eradication. On the other hand, Shigella-survived strains changed their outer membrane protein profiles, secreted proteins, and lipopolysaccharides. Also, as shown by electron microscopy transmission, morphological alterations were manifested by an internal cytoplasm disorganized and membrane envelope breaks. Taken together, the focus of interest of our study is to know the adaptive mechanism of UV-C resistance of Shigella strains.

  5. Applying Mathematical Tools to Accelerate Vaccine Development: Modeling Shigella Immune Dynamics

    Science.gov (United States)

    Davis, Courtney L.; Wahid, Rezwanul; Toapanta, Franklin R.; Simon, Jakub K.

    2013-01-01

    We establish a mathematical framework for studying immune interactions with Shigella, a bacteria that kills over one million people worldwide every year. The long-term goal of this novel approach is to inform Shigella vaccine design by elucidating which immune components and bacterial targets are crucial for establishing Shigella immunity. Our delay differential equation model focuses on antibody and B cell responses directed against antigens like lipopolysaccharide in Shigella’s outer membrane. We find that antibody-based vaccines targeting only surface antigens cannot elicit sufficient immunity for protection. Additional boosting prior to infection would require a four-orders-of-magnitude increase in antibodies to sufficiently prevent epithelial invasion. However, boosting anti-LPS B memory can confer protection, which suggests these cells may correlate with immunity. We see that IgA antibodies are slightly more effective per molecule than IgG, but more total IgA is required due to spatial functionality. An extension of the model reveals that targeting both LPS and epithelial entry proteins is a promising avenue to advance vaccine development. This paper underscores the importance of multifaceted immune targeting in creating an effective Shigella vaccine. It introduces mathematical models to the Shigella vaccine development effort and lays a foundation for joint theoretical/experimental/clinical approaches to Shigella vaccine design. PMID:23589755

  6. Prevalence and antimicrobial susceptibility patterns of Shigella among acute diarrheal outpatients in Mekelle hospital, Northern Ethiopia.

    Science.gov (United States)

    Gebrekidan, Atsebaha; Dejene, Tsehaye Asmelash; Kahsay, Getahun; Wasihun, Araya Gebreysus

    2015-10-28

    Emergence of increased antimicrobial resistance of Shigella species is a global challenge, particularly in developing countries where increased misuse of antimicrobial agents occurs. There is no published data in the study area on the prevalence and antimicrobial susceptibility patterns of Shigella among acute diarrheal patients. This study was therefore, under taken to fill this gap. Using cross sectional study method, stool specimens were collected from 216 patients with acute diarrhea at Mekelle Hospital from August to November 2014. Standard bacteriological methods were used to isolate and determine the antimicrobial susceptibility patterns of the isolates, and data were analyzed using SPSS version 20. Out of the total 216 participants, Shigella was isolated from 15 (6.9 %) of the participants. Ten (66.7 %) of the positive isolates were from children Shigella showed 100, 86.7 and 66.7 % resistance to amoxicillin, amoxicillin and cotrimoxazole respectively. Low levels of resistance were observed for norfloxacin and ciprofloxacin (6.7 % each). Overall, 80 % of the isolates showed multidrug resistance. Shigella isolates were highly resistant to amoxicillin, amoxicillin and cotrimoxazole. However, ciprofloxacin and norfloxacin were effective. Antibiotic surveillance is needed to prevent further emergence of drug resistant Shigella strains. More has to be done in the availability of latrine, supply of safe drinking water to the community to reduce the disease burden.

  7. [Molecular characteristics of Clustered Regularly Interspaced Short Palindromic Repeat in Shigella].

    Science.gov (United States)

    Xue, Zerun; Wang, Yingfang; Duan, Guangcai; Yang, Haiyan; Xi, Yuanlin; Wang, Pengfei; Wang, Linlin; Guo, Xiangjiao

    2015-08-01

    To detect the molecular characteristics of Clustered Regularly Interspaced Short Palindromic Repeat (CRISPR) in Shigella and to analyze the distribution of CRISPR related to the time of isolation. Of the 52 Shigella strains, 41 were isolated from Henan, 6 from Jiangxi and 5 isolated from Beijing. Both CRISPR locus of S1, S2, S3 and S4 in Shigella were detected by polymerase chain reaction (PCR). The PCR products were sequenced and compared. The positive rates of CRISPR locus in Shigella were 33.69% (S1), 50.00% (S2), 82.69% (S3) and 73.08% (S4), respectively. Two subtypes were discovered in S1 and S3 locus. Three subtypes were discovered in S2 locus. Four different subtypes were discovered in S4 locus. The isolates from Henan strains were divided into two groups by the time of isolation. Distributions of S1 were different, before or after 2004, on Shigella. S1 could not be detected after 2004. There were no statistical differences of S2, S3 and S4 in two groups. Different CRISPR subtypes or Shigella were discovered. A significant correlation was noticed between the CRISPR S1 related to the time of isolation but not between S2, S3 or S4 on the time of isolation.

  8. Shigella IpaH Family Effectors as a Versatile Model for Studying Pathogenic Bacteria.

    Science.gov (United States)

    Ashida, Hiroshi; Sasakawa, Chihiro

    2015-01-01

    Shigella spp. are highly adapted human pathogens that cause bacillary dysentery (shigellosis). Via the type III secretion system (T3SS), Shigella deliver a subset of virulence proteins (effectors) that are responsible for pathogenesis, with functions including pyroptosis, invasion of the epithelial cells, intracellular survival, and evasion of host immune responses. Intriguingly, T3SS effector activity and strategies are not unique to Shigella, but are shared by many other bacterial pathogens, including Salmonella, Yersinia, and enteropathogenic Escherichia coli (EPEC). Therefore, studying Shigella T3SS effectors will not only improve our understanding of bacterial infection systems, but also provide a molecular basis for developing live bacterial vaccines and antibacterial drugs. One of Shigella T3SS effectors, IpaH family proteins, which have E3 ubiquitin ligase activity and are widely conserved among other bacterial pathogens, are very relevant because they promote bacterial survival by triggering cell death and modulating the host immune responses. Here, we describe selected examples of Shigella pathogenesis, with particular emphasis on the roles of IpaH family effectors, which shed new light on bacterial survival strategies and provide clues about how to overcome bacterial infections.

  9. Shigella IpaH family effectors as a versatile model for studying pathogenic bacteria

    Directory of Open Access Journals (Sweden)

    Hiroshi eAshida

    2016-01-01

    Full Text Available Shigella spp. are highly adapted human pathogens that cause bacillary dysentery (shigellosis. Via the type III secretion system (T3SS, Shigella deliver a subset of virulence proteins (effectors that are responsible for pathogenesis, with functions including pyroptosis, invasion of the epithelial cells, intracellular survival, and evasion of host immune responses. Intriguingly, T3SS effector activity and strategies are not unique to Shigella, but are shared by many other bacterial pathogens, including Salmonella, Yersinia, and enteropathogenic Escherichia coli (EPEC. Therefore, studying Shigella T3SS effectors will not only improve our understanding of bacterial infection systems, but also provide a molecular basis for developing live bacterial vaccines and antibacterial drugs. One of Shigella T3SS effectors, IpaH family proteins, which have E3 ubiquitin ligase activity and are widely conserved among other bacterial pathogens, are very relevant because they promote bacterial survival by triggering cell death and modulating the host immune responses. Here, we describe selected examples of Shigella pathogenesis, with particular emphasis on the roles of IpaH family effectors, which shed new light on bacterial survival strategies and provide clues about how to overcome bacterial infections.

  10. Cytotoxicity of leukocytes from normal and Shigella-susceptible (opium-treated) guinea pigs against virulent Shigella sonnei.

    Science.gov (United States)

    Morgan, D R; DuPont, H L; Wood, L V; Kohl, S

    1984-01-01

    Intraepithelial lymphocytes were collected from the ileum of adult Hartley strain guinea pigs and used as effector cells in a 60-min bactericidal assay with virulent Shigella sonnei as target cells. Natural killer cytotoxicity (NKC) and antibody-dependent cellular cytotoxicity (ADCC) were measured and correlated with the resistance of the animals to infection by S. sonnei. Normal guinea pig intraepithelial lymphocytes exhibited mean NKC and ADCC values of 22.8 +/- 5.0 and 34.1 +/- 13.6, respectively. These animals were resistant to oral challenge with virulent S. sonnei. Intraepithelial lymphocytes from guinea pigs which were fasted for 4 days demonstrated NKC and ADCC values similar to those of normal animals (31.0 +/- 8.1 and 41.7 +/- 6.7, respectively). These animals also were resistant to oral challenge. Intraepithelial lymphocytes from guinea pigs which were given 1 ml of deodorized tincture of opium 2 h before cell collection demonstrated deficient NKC (4.7 +/- 4.2) and ADCC (5.3 +/- 4.9) values but remained resistant to infection by S. sonnei. When guinea pigs were fasted for 4 days and given opium, deficient NKC (2.0 +/- 2.0) and ADCC (1.3 +/- 1.3) values were demonstrated; this group of animals was susceptible to infection by S. sonnei (P less than 0.04). These experiments demonstrated that opium treatment depresses one form of gut immunity. When combined with starvation, opium treatment may increase susceptibility to infection by shigellae by modulation of immunity in addition to the effects on gut motility and bacterial flora. PMID:6384044

  11. Pre-Clinical Testing of Real-Time PCR Assays for Diarrheal Disease Agents of Genera Escherichia and Shigella

    Science.gov (United States)

    2014-05-16

    FOR DIARRHEAL DISEASE AGENTS OF GENERA ESCHERICHIA AND SHIGELLA May 16, 2014 Reporting Period: October 1, 2010 to September 30, 2013...10-2010 - 30-09-2013 PRE-CLINICAL TESTING OF REAL-TIME PCR ASSAYS FOR DIARRHEAL DISEASE AGENTS OF GENERA ESCHERICHIA AND SHIGELLA ...Texas (MOA 2007 - 2013. Agreement No.: DODI 4000.19; AFI 25-201). Pre-clinical test results qualify ETEC and Shigella real-time PCR assays as lead

  12. Antibiotics for the treatment of Cholera, Shigella and Cryptosporidium in children.

    Science.gov (United States)

    Das, Jai K; Ali, Anum; Salam, Rehana A; Bhutta, Zulfiqar A

    2013-01-01

    Diarrhea is a major contributor to the burden of morbidity and mortality in children; it accounts for a median of 11% of all deaths among children aged less than 5 years, amounting to approximately 0.8 million deaths per year. Currently there is a dearth of literature exploring the effectiveness of antibiotics for diarrhea due to Cholera, Shigella and cryptosporidiosis in children. We reviewed the literature reporting the effect of antibiotics for the treatment of diarrhea due to Cholera, Shigella and Cryptosporidium in children under five years. We used a standardized abstraction and grading format and performed meta-analyses to determine the effect of the treatment with various antibiotics on mortality and rates of clinical and bacteriological/parasitological failure. The CHERG Standard Rules were applied to determine the final effect of treatment with antibiotics on diarrhea morbidity and mortality. For Cholera; the evidence was weak to recommend any effect on mortality. For Shigella; there was no data on mortality; either all-cause or cause specific, hence we used clinical failure rates as a proxy for Shigella deaths and propose that treatment of Shigella dysentery with antibiotics can result in a 82% reduction in diarrhea mortality due to Shigella. For cryptosporidiosis; there was data on all-cause mortality but the evidence was weak hence we used clinical failure rates as a proxy for mortality to estimate that antimicrobial treatment of diarrhea due to cryptosporidiosis can result in a 54% reduction in mortality. There is evidence to recommend antibiotic use for reduction of morbidity and mortality due to Cholera, Shigella and Cryptosporidium. We recommend that more clinical trials should be conducted to evaluate the efficacy and safety of first- and second- line drugs currently in use for treatment for diarrhea and dysentery in both developing and developed countries.

  13. The Emergence of Quinolone Resistant Shigella sonnei, Pondicherry, India.

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    Ankita Das

    Full Text Available Ciprofloxacin resistant Shigella sonnei across the globe have been increasing alarmingly. In order to understand the emergence of S.sonnei with respect to ciprofloxacin resistance in our patient population, the following study was carried out. Of the 184 Shigella sp. Isolated from 2012 to 2015, 34 S.sonnei which were confirmed by standard methods and subjected to antimicrobial susceptibility testing were selected. The minimum inhibitory concentrations (MICs of 16/34 quinolone resistant isolates tested ranged from 4micrograms/ml to 16micrograms/ml for ciprofloxacin, from 16 micrograms/ml to 64 micrograms/ml for ofloxacin and from 16micrograms/ml to 64micrograms/ml for levofloxacin. Sequence determination of the quinolone resistance determining regions of gyrA, gyrB, parC, and parE genes showed mutations in GyrA at Gln69/Trp, Phe71/Ser, Ser72/Pro, Met75/Leu, Ser90/Cys, Met94/Leu, His106/Pro, Asn161/His, Thr163/Ala and in ParC at Ala64/Asp. Among the plasmid-mediated quinolone resistance (PMQRs targets investigated,qnrB was the most (93.7% prevalent followed by qnrC (18.7%. None hadqnrA, qnrS and qepA. Two (0.1% of the isolates harboured theaac(6'-lb gene. Drug accumulation assay detected the presence of efflux pump activity in 9/15 (60% among ciprofloxacin resistant isolates. All isolates harboured the ipaH gene followed by ial (17.6%, sen (11.7%, set1A&set1B (5.8% genes. None had stx1 element. PCR for Enterobacterial repetitive intergenic consensus (ERIC sequences resulted in 4 unique clusters, of which Type III was the most (44% dominant but there was no correlation between the ERIC types and the antibiotic resistance pattern or the virulence profile. A documented increase in S.sonnei harbouring the qnrgenes and some unusual genes like set1Aand indicate an ongoing process of horizontal gene transfer. The accumulation of novel mutations in GyrA and ParC in the presence of efflux pump and PMQR genes contributed to the raised MIC to quinolones

  14. Immunization of Mice with a Live Transconjugant Shigella Hybrid Strain Induced Th1 and Th17 Cell-Mediated Immune Responses and Confirmed Passive Protection Against Heterologous Shigellae.

    Science.gov (United States)

    Nag, D; Koley, H; Sinha, R; Mukherjee, P; Sarkar, C; Withey, J H; Gachhui, R

    2016-02-01

    An avirulent, live transconjugant Shigella hybrid (LTSHΔstx) strain was constructed in our earlier study by introducing a plasmid vector, pPR1347, into a Shiga toxin gene deleted Shigella dysenteriae 1. Three successive oral administrations of LTSHΔstx to female adult mice produced comprehensive passive heterologous protection in their offspring against challenge with wild-type shigellae. Production of NO and different cytokines such asIL-12p70, IL-1β and IL-23 in peritoneal mice macrophages indicated that LTSHΔstx induced innate and adaptive immunity in mice. Furthermore, production of IFN-γ, IL-10 and IL-17 in LTSH-primed splenic CD4+ T cell suggested that LTSHΔstx may induce Th1 and Th17 cell-mediated immune responses. Exponential increase of the serum IgG and IgA titre against whole shigellae was observed in immunized adult mice during and after the immunization with the highest peak on day 35. Antigen-specific sIgA was also determined from intestinal lavage of immunized mice. The stomach extracts of neonates from immunized mice, mainly containing mother's milk, contained significant levels of anti-LTSHΔstx immunoglobulin. These studies suggest that the LTSHΔstx could be a new live oral vaccine candidate against shigellosis in the near future. © 2015 The Foundation for the Scandinavian Journal of Immunology.

  15. Global phylogeography and evolutionary history of Shigella dysenteriae type 1.

    Science.gov (United States)

    Njamkepo, Elisabeth; Fawal, Nizar; Tran-Dien, Alicia; Hawkey, Jane; Strockbine, Nancy; Jenkins, Claire; Talukder, Kaisar A; Bercion, Raymond; Kuleshov, Konstantin; Kolínská, Renáta; Russell, Julie E; Kaftyreva, Lidia; Accou-Demartin, Marie; Karas, Andreas; Vandenberg, Olivier; Mather, Alison E; Mason, Carl J; Page, Andrew J; Ramamurthy, Thandavarayan; Bizet, Chantal; Gamian, Andrzej; Carle, Isabelle; Sow, Amy Gassama; Bouchier, Christiane; Wester, Astrid Louise; Lejay-Collin, Monique; Fonkoua, Marie-Christine; Le Hello, Simon; Blaser, Martin J; Jernberg, Cecilia; Ruckly, Corinne; Mérens, Audrey; Page, Anne-Laure; Aslett, Martin; Roggentin, Peter; Fruth, Angelika; Denamur, Erick; Venkatesan, Malabi; Bercovier, Hervé; Bodhidatta, Ladaporn; Chiou, Chien-Shun; Clermont, Dominique; Colonna, Bianca; Egorova, Svetlana; Pazhani, Gururaja P; Ezernitchi, Analia V; Guigon, Ghislaine; Harris, Simon R; Izumiya, Hidemasa; Korzeniowska-Kowal, Agnieszka; Lutyńska, Anna; Gouali, Malika; Grimont, Francine; Langendorf, Céline; Marejková, Monika; Peterson, Lorea A M; Perez-Perez, Guillermo; Ngandjio, Antoinette; Podkolzin, Alexander; Souche, Erika; Makarova, Mariia; Shipulin, German A; Ye, Changyun; Žemličková, Helena; Herpay, Mária; Grimont, Patrick A D; Parkhill, Julian; Sansonetti, Philippe; Holt, Kathryn E; Brisse, Sylvain; Thomson, Nicholas R; Weill, François-Xavier

    2016-03-21

    Together with plague, smallpox and typhus, epidemics of dysentery have been a major scourge of human populations for centuries(1). A previous genomic study concluded that Shigella dysenteriae type 1 (Sd1), the epidemic dysentery bacillus, emerged and spread worldwide after the First World War, with no clear pattern of transmission(2). This is not consistent with the massive cyclic dysentery epidemics reported in Europe during the eighteenth and nineteenth centuries(1,3,4) and the first isolation of Sd1 in Japan in 1897(5). Here, we report a whole-genome analysis of 331 Sd1 isolates from around the world, collected between 1915 and 2011, providing us with unprecedented insight into the historical spread of this pathogen. We show here that Sd1 has existed since at least the eighteenth century and that it swept the globe at the end of the nineteenth century, diversifying into distinct lineages associated with the First World War, Second World War and various conflicts or natural disasters across Africa, Asia and Central America. We also provide a unique historical perspective on the evolution of antibiotic resistance over a 100-year period, beginning decades before the antibiotic era, and identify a prevalent multiple antibiotic-resistant lineage in South Asia that was transmitted in several waves to Africa, where it caused severe outbreaks of disease.

  16. Update on: Shigella new serogroups/serotypes and their antimicrobial resistance.

    Science.gov (United States)

    Muthuirulandi Sethuvel, D P; Devanga Ragupathi, N K; Anandan, S; Veeraraghavan, B

    2017-01-01

    Shigellosis represents a major burden of disease in developing countries. A low infectious dose allows the disease to be spread effectively. Although shigellosis is mostly a self-limiting disease, antibiotics are recommended to reduce deaths, disease symptoms and organism-shedding time. However, in India, antimicrobial resistance among the genus Shigella is more common than among any other enteric bacteria. Notably, new serotypes or subserotypes in Shigella are reported from various parts of the world. Identification of new subserotypes of Shigella spp. is becoming a major issue as these strains are nontypeable by conventional serotyping. The commercially available antisera may not cover all possible epitopes of the O lipopolysaccharide antigen of Shigella serotypes. Therefore, molecular methods which most closely approach the resolution of full serotyping are necessary to identify such strains. In addition, the knowledge of a prevalent serotype in various geographic regions may assist in formulating strategies such as the development of a vaccine to prevent infection especially when the immunity to disease is serotype specific, and to understand the disease burden caused by new Shigella serotypes. © 2016 The Society for Applied Microbiology.

  17. [Detection of CRISPR and its relationship to drug resistance in Shigella].

    Science.gov (United States)

    Wang, Linlin; Wang, Yingfang; Duan, Guangcai; Xue, Zerun; Guo, Xiangjiao; Wang, Pengfei; Xi, Yuanlin; Yang, Haiyan

    2015-04-04

    To detect clustered regularly interspaced short palindromic repeats (CRISPR) in Shigella, and to analyze its relationship to drug resistance. Four pairs of primers were used for the detection of convincing CRISPR structures CRISPR-S2 and CRISPR-S4, questionable CRISPR structures CRISPR-S1 and CRISPR-S3 in 60 Shigella strains. All primers were designed using sequences in CRISPR database. CRISPR Finder was used to analyze CRISPR and susceptibilities of Shigella strains were tested by agar diffusion method. Furthermore, we analyzed the relationship between drug resistance and CRISPR-S4. The positive rate of convincing CRISPR structures was 95%. The four CRISPR loci formed 12 spectral patterns (A-L), all of which contained convincing CRISPR structures except type K. We found one new repeat and 12 new spacers. The multi-drug resistance rate was 53. 33% . We found no significant difference between CRISPR-S4 and drug resistant. However, the repeat sequence of CRISPR-S4 in multi- or TE-resistance strains was mainly R4.1 with AC deletions in the 3' end, and the spacer sequences of CRISPR-S4 in multi-drug resistance strains were mainly Sp5.1, Sp6.1 and Sp7. CRISPR was common in Shigella. Variations df repeat sequences and diversities of spacer sequences might be related to drug resistance in Shigella.

  18. Antimicrobial resistance in Shigella spp. causing traveller's diarrhoea (1995-2010): a retrospective analysis.

    Science.gov (United States)

    Pons, M J; Gomes, C; Martínez-Puchol, S; Ruiz, L; Mensa, L; Vila, J; Gascón, J; Ruiz, J

    2013-01-01

    Shigellosis is a global human health problem causing an important morbidity among travellers returning from tropical areas. This study was aimed to describe the evolution of antimicrobial resistance profile in Shigella spp. isolated between the years 1995-2010 in patients with traveller's diarrhoea (TD) returning from tropical areas. The levels of antimicrobial resistance were tested in a total of 191 Shigella spp. isolated during the period from 1995 to 2010. A decrease of cases of diarrhoea caused by Shigella has been observed in recent years. A wide spectrum of antibiotic resistance was observed among Shigella spp. These isolates showed high levels of resistance to tetracycline (84%), co-trimoxazole (75.5%), and ampicillin (45.5%). The resistance was low to ciprofloxacin (2.1%), azithromycin (3.9%) and furazolidone (8.4%). According to the period, in the case of ampicillin, amoxicillin plus clavulanic acid, chloramphenicol, values of resistance were significantly decreasing from 1995-2000 to 2001-2010, (62.5% vs. 28.4%, 19.8% vs. 6.6%, 23.4 vs. 10.4%, respectively). Meanwhile in nalidixic acid and tetracycline the evolution of resistance has increased over time. A decrease in the isolation number of Shigella spp. causing TD has been observed. Differential trends in the evolution of the levels of resistance to the tested antibacterial agents have been observed. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. Polymorphism of CRISPR shows separated natural groupings of Shigella subtypes and evidence of horizontal transfer of CRISPR

    Science.gov (United States)

    Yang, Chaojie; Li, Peng; Su, Wenli; Li, Hao; Liu, Hongbo; Yang, Guang; Xie, Jing; Yi, Shengjie; Wang, Jian; Cui, Xianyan; Wu, Zhihao; Wang, Ligui; Hao, Rongzhang; Jia, Leili; Qiu, Shaofu; Song, Hongbin

    2015-01-01

    Clustered, regularly interspaced, short palindromic repeats (CRISPR) act as an adaptive RNA-mediated immune mechanism in bacteria. They can also be used for identification and evolutionary studies based on polymorphisms within the CRISPR locus. We amplified and analyzed 6 CRISPR loci from 237 Shigella strains belonging to the 4 species groups, as well as 13 Escherichia coli strains. The CRISPR-associated (cas) gene sequence arrays of these strains were screened and compared. The CRISPR sequences from Shigella were conserved among subtypes, suggesting that CRISPR may represent a new identification tool for the detection and discrimination of Shigella species. Secondary structure analysis showed a different stem-loop structure at the terminal repeat, suggesting a distinct recognition mechanism in the formation of crRNA. In addition, the presence of “self-target” spacers and polymorphisms within CRISPR in Shigella indicated a selective pressure for inhibition of this system, which has the potential to damage “self DNA.” Homology analysis of spacers showed that CRISPR might be involved in the regulation of virulence transmission. Phylogenetic analysis based on CRISPR sequences from Shigella and E. coli indicated that although phenotypic properties maintain convergent evolution, the 4 Shigella species do not represent natural groupings. Surprisingly, comparative analysis of Shigella repeats with other species provided new evidence for CRISPR horizontal transfer. Our results suggested that CRISPR analysis is applicable for the detection of Shigella species and for investigation of evolutionary relationships. PMID:26327282

  20. Polymorphism of CRISPR shows separated natural groupings of Shigella subtypes and evidence of horizontal transfer of CRISPR.

    Science.gov (United States)

    Yang, Chaojie; Li, Peng; Su, Wenli; Li, Hao; Liu, Hongbo; Yang, Guang; Xie, Jing; Yi, Shengjie; Wang, Jian; Cui, Xianyan; Wu, Zhihao; Wang, Ligui; Hao, Rongzhang; Jia, Leili; Qiu, Shaofu; Song, Hongbin

    2015-01-01

    Clustered, regularly interspaced, short palindromic repeats (CRISPR) act as an adaptive RNA-mediated immune mechanism in bacteria. They can also be used for identification and evolutionary studies based on polymorphisms within the CRISPR locus. We amplified and analyzed 6 CRISPR loci from 237 Shigella strains belonging to the 4 species groups, as well as 13 Escherichia coli strains. The CRISPR-associated (cas) gene sequence arrays of these strains were screened and compared. The CRISPR sequences from Shigella were conserved among subtypes, suggesting that CRISPR may represent a new identification tool for the detection and discrimination of Shigella species. Secondary structure analysis showed a different stem-loop structure at the terminal repeat, suggesting a distinct recognition mechanism in the formation of crRNA. In addition, the presence of "self-target" spacers and polymorphisms within CRISPR in Shigella indicated a selective pressure for inhibition of this system, which has the potential to damage "self DNA." Homology analysis of spacers showed that CRISPR might be involved in the regulation of virulence transmission. Phylogenetic analysis based on CRISPR sequences from Shigella and E. coli indicated that although phenotypic properties maintain convergent evolution, the 4 Shigella species do not represent natural groupings. Surprisingly, comparative analysis of Shigella repeats with other species provided new evidence for CRISPR horizontal transfer. Our results suggested that CRISPR analysis is applicable for the detection of Shigella species and for investigation of evolutionary relationships.

  1. [Bioinformatics Analysis of Clustered Regularly Interspaced Short Palindromic Repeats in the Genomes of Shigella].

    Science.gov (United States)

    Wang, Pengfei; Wang, Yingfang; Duan, Guangcai; Xue, Zerun; Wang, Linlin; Guo, Xiangjiao; Yang, Haiyan; Xi, Yuanlin

    2015-04-01

    This study was aimed to explore the features of clustered regularly interspaced short palindromic repeats (CRISPR) structures in Shigella by using bioinformatics. We used bioinformatics methods, including BLAST, alignment and RNA structure prediction, to analyze the CRISPR structures of Shigella genomes. The results showed that the CRISPRs existed in the four groups of Shigella, and the flanking sequences of upstream CRISPRs could be classified into the same group with those of the downstream. We also found some relatively conserved palindromic motifs in the leader sequences. Repeat sequences had the same group with corresponding flanking sequences, and could be classified into two different types by their RNA secondary structures, which contain "stem" and "ring". Some spacers were found to homologize with part sequences of plasmids or phages. The study indicated that there were correlations between repeat sequences and flanking sequences, and the repeats might act as a kind of recognition mechanism to mediate the interaction between foreign genetic elements and Cas proteins.

  2. UJI DAYA HAMBAT PERASAN BUAH JERUK SIAM BANJAR (Citrus reticulata TERHADAP PERTUMBUHAN Shigella dysenteriae

    Directory of Open Access Journals (Sweden)

    Eka Kumalasari

    2017-10-01

    Full Text Available Siam orange (Citrus reticulata is kind of orange which a lot in Sout Borneo and a national top variety called banjar siam orange. Orange contains secondary metabolites flavonoids, saponins, alkaloids which cause damage bacteria cell wall permeability. Objective of this study is to find out inhibition siam orange fruit squeeze to Shigella dysenteriae growth. This study is an experimental research laboratory. Inhibition test of siam banjar orange (Citrus reticulata fruit squeeze to Shigella dysenteriae growthwas conducted with diffusion methodwhich performed at Bacteriology Laboratory of Banjarbaru Center Veterinary. Result of phytochemicals screening showedthat banjar siam orange fruit squeeze contain alkaloids, saponins, and flavonoids. Result of the study showed banjar siam orange fruit squeeze has the ability to inhibite Shigella dysenteriae growth with 25%, 50%, 75% and 100% concentrations. The higher concentration of banjar siam orange squeeze, the greater diameter of inhibition zone result.

  3. Accurate differentiation of Escherichia coli and Shigella serogroups: challenges and strategies

    Directory of Open Access Journals (Sweden)

    N.K. Devanga Ragupathi

    2018-01-01

    Full Text Available Shigella spp. and Escherichia coli are closely related; both belong to the family Enterobacteriaceae. Phenotypically, Shigella spp. and E. coli share many common characteristics, yet they have separate entities in epidemiology and clinical disease, which poses a diagnostic challenge. We collated information for the best possible approach to differentiate clinically relevant E. coli from Shigella spp. We found that a molecular approach is required for confirmation. High discriminatory potential is seen with whole genome sequencing analysed for k-mers and single nucleotide polymorphism. Among these, identification using single nucleotide polymorphism is easy to perform and analyse, and it thus appears more promising. Among the nonmolecular methods, matrix-assisted desorption ionization–time of flight mass spectrometry may be applicable when data analysis is assisted with advanced analytic tools. Keywords: 16S rRNA, k-mer, MALDI-TOF MS, single nucleotide polymorphism, whole genome sequencing

  4. Whole-genome phylogeny of Escherichia coli/Shigella group by feature frequency profiles (FFPs)

    Science.gov (United States)

    Sims, Gregory E.; Kim, Sung-Hou

    2011-01-01

    A whole-genome phylogeny of the Escherichia coli/Shigella group was constructed by using the feature frequency profile (FFP) method. This alignment-free approach uses the frequencies of l-mer features of whole genomes to infer phylogenic distances. We present two phylogenies that accentuate different aspects of E. coli/Shigella genomic evolution: (i) one based on the compositions of all possible features of length l = 24 (∼8.4 million features), which are likely to reveal the phenetic grouping and relationship among the organisms and (ii) the other based on the compositions of core features with low frequency and low variability (∼0.56 million features), which account for ∼69% of all commonly shared features among 38 taxa examined and are likely to have genome-wide lineal evolutionary signal. Shigella appears as a single clade when all possible features are used without filtering of noncore features. However, results using core features show that Shigella consists of at least two distantly related subclades, implying that the subclades evolved into a single clade because of a high degree of convergence influenced by mobile genetic elements and niche adaptation. In both FFP trees, the basal group of the E. coli/Shigella phylogeny is the B2 phylogroup, which contains primarily uropathogenic strains, suggesting that the E. coli/Shigella ancestor was likely a facultative or opportunistic pathogen. The extant commensal strains diverged relatively late and appear to be the result of reductive evolution of genomes. We also identify clade distinguishing features and their associated genomic regions within each phylogroup. Such features may provide useful information for understanding evolution of the groups and for quick diagnostic identification of each phylogroup. PMID:21536867

  5. Association Between Shigella Infection and Diarrhea Varies Based on Location and Age of Children.

    Science.gov (United States)

    Lindsay, Brianna; Saha, Debasish; Sanogo, Doh; Das, Sumon Kumar; Omore, Richard; Farag, Tamer H; Nasrin, Dilruba; Li, Shan; Panchalingam, Sandra; Levine, Myron M; Kotloff, Karen; Nataro, James P; Magder, Laurence; Hungerford, Laura; Faruque, A S G; Oundo, Joseph; Hossain, M Anowar; Adeyemi, Mitchell; Stine, Oscar Colin

    2015-11-01

    Molecular identification of the invasion plasmid antigen-H (ipaH) gene has been established as a useful detection mechanism for Shigella spp. The Global Enteric Multicenter Study (GEMS) identified the etiology and burden of moderate-to-severe diarrhea (MSD) in sub-Saharan Africa and south Asia using a case-control study and traditional culture techniques. Here, we used quantitative polymerase chain reaction (qPCR) to identify Shigella spp. in 2,611 stool specimens from GEMS and compared these results to those using culture. Demographic and nutritional characteristics were assessed as possible risk factors. The qPCR identified more cases of shigellosis than culture; however, the distribution of demographic characteristics was similar by both methods. In regression models adjusting for Shigella quantity, age, and site, children who were exclusively breast-fed had significantly lower odds of MSD compared with children who were not breast-fed (odds ratio [OR] = 0.47, 95% confidence interval (CI) = 0.28-0.81). The association between Shigella quantity and MSD increased with age, with a peak in children of 24-35 months of age (OR = 8.2, 95% CI = 4.3-15.7) and the relationship between Shigella quantity and disease was greatest in Bangladesh (OR = 13.2, 95% CI = 7.3-23.8). This study found that qPCR identified more cases of Shigella and age, site, and breast-feeding status were significant risk factors for MSD. © The American Society of Tropical Medicine and Hygiene.

  6. Multifactor Regulation of the MdtJI Polyamine Transporter in Shigella.

    Directory of Open Access Journals (Sweden)

    Adriano Leuzzi

    Full Text Available The polyamine profile of Shigella, the etiological agent of bacillary dysentery in humans, differs markedly from that of E. coli, its innocuous commensal ancestor. Pathoadaptive mutations such as the loss of cadaverine and the increase of spermidine favour the full expression of the virulent phenotype of Shigella. Spermidine levels affect the expression of the MdtJI complex, a recently identified efflux pump belonging to the small multi-drug resistance family of transporters. In the present study, we have addressed the regulation of the mdtJI operon in Shigella by asking which factors influence its expression as compared to E. coli. In particular, after identifying the mdtJI promoter by primer extension analysis, in vivo transcription assays and gel-retardation experiments were carried out to get insight on the silencing of mdtJI in E. coli. The results indicate that H-NS, a major nucleoid protein, plays a key role in repressing the mdtJI operon by direct binding to the regulatory region. In the Shigella background mdtJI expression is increased by the high levels of spermidine typically found in this microorganism and by VirF, the plasmid-encoded regulator of the Shigella virulence regulatory cascade. We also show that the expression of mdtJI is stimulated by bile components. Functional analyses reveal that MdtJI is able to promote the excretion of putrescine, the spermidine precursor. This leads us to consider the MdtJI complex as a possible safety valve allowing Shigella to maintain spermidine to a level optimally suited to survival within infected macrophages and, at the same time, prevent toxicity due to spermidine over-accumulation.

  7. Attenuated Shigella as a DNA Delivery Vehicle for DNA-Mediated Immunization

    Science.gov (United States)

    Sizemore, Donata R.; Branstrom, Arthur A.; Sadoff, Jerald C.

    1995-10-01

    Direct inoculation of DNA, in the form of purified bacterial plasmids that are unable to replicate in mammalian cells but are able to direct cell synthesis of foreign proteins, is being explored as an approach to vaccine development. Here, a highly attenuated Shigella vector invaded mammalian cells and delivered such plasmids into the cytoplasm of cells, and subsequent production of functional foreign protein was measured. Because this Shigella vector was designed to deliver DNA to colonic mucosa, the method is a potential basis for oral and other mucosal DNA immunization and gene therapy strategies.

  8. Evaluation of an intragastric challenge model for Shigella dysenteriae 1 in rhesus monkeys (Macaca mulatta) for the pre-clinical assessment of Shigella vaccine formulations

    OpenAIRE

    Islam, Dilara; Ruamsap, Nattaya; Khantapura, Patchariya; Aksomboon, Ajchara; Srijan, Apichai; Wongstitwilairoong, Boonchai; Bodhidatta, Ladaporn; Gettayacamin, Montip; Venkatesan, Malabi M; Mason, Carl J

    2013-01-01

    Shigellosis is a worldwide disease, characterized by abdominal pain, fever, vomiting, and the passage of blood- and mucus-streaked stools. Rhesus monkeys and other primates are the only animals that are naturally susceptible to shigellosis. A suitable animal model is required for the pre-clinical evaluation of vaccines candidates. In this study, the minimal dose of Shigella dysenteriae1 1617 strain required to produce dysentery in four of five (80% attack rate) monkeys using an escalating dos...

  9. Prevalence of Shigella among diarrheic children under-5 years of age attending at Mekelle health center, north Ethiopia.

    Science.gov (United States)

    Kahsay, Atsebaha Gebrekidan; Teklemariam, Zelalem

    2015-12-15

    Shigellosis is recognized as a major global public health problem especially in developing countries particularly in children under-5 years of age. Therefore; the objective of this study was to determine the prevalence of Shigella among diarrheic children under-5 years of age attending at Mekelle health center, north Ethiopia. A cross-sectional study was conducted among diarrheic children under-5 years of age from March to May, 2012. Structured questionnaire was used to collect the data. Study participants were recruited by convenience sampling technique. Shigella was isolated and identified using standard bacteriological techniques. A total of 241 study participants were included in the study. The overall prevalence of Shigella in this study was 13.3% (32/241). High prevalence of Shigella (22.6%) was revealed from the age group of 12-23 months. No Shigella was isolated from the age group of 0-5 months. Majority of the isolates of Shigella were from bloody and mucoid diarrhea. There was high prevalence of Shigella infection in this study. Children among the age group of 12-23 months were highly affected. Therefore; responsible bodies should work hard on preventive measures to reduce or eradicate the problem occurred due to shigellosis.

  10. Rapid detection of Shigella and enteroinvasive Escherichia coli in produce enrichments by a conventional multiplex PCR assay.

    Science.gov (United States)

    Binet, Rachel; Deer, Deanne M; Uhlfelder, Samantha J

    2014-06-01

    Faster detection of contaminated foods can prevent adulterated foods from being consumed and minimize the risk of an outbreak of foodborne illness. A sensitive molecular detection method is especially important for Shigella because ingestion of as few as 10 of these bacterial pathogens can cause disease. The objectives of this study were to compare the ability of four DNA extraction methods to detect Shigella in six types of produce, post-enrichment, and to evaluate a new and rapid conventional multiplex assay that targets the Shigella ipaH, virB and mxiC virulence genes. This assay can detect less than two Shigella cells in pure culture, even when the pathogen is mixed with background microflora, and it can also differentiate natural Shigella strains from a control strain and eliminate false positive results due to accidental laboratory contamination. The four DNA extraction methods (boiling, PrepMan Ultra [Applied Biosystems], InstaGene Matrix [Bio-Rad], DNeasy Tissue kit [Qiagen]) detected 1.6 × 10(3)Shigella CFU/ml post-enrichment, requiring ∼18 doublings to one cell in 25 g of produce pre-enrichment. Lower sensitivity was obtained, depending on produce type and extraction method. The InstaGene Matrix was the most consistent and sensitive and the multiplex assay accurately detected Shigella in less than 90 min, outperforming, to the best of our knowledge, molecular assays currently in place for this pathogen. Published by Elsevier Ltd.

  11. [Changes of resistant phenotype and CRISPR/Cas system of four Shigella strains passaged for 90 times without antibiotics].

    Science.gov (United States)

    Zhang, B; Hong, L J; Duan, G C; Liang, W J; Yang, H Y; Xi, Y L

    2017-02-10

    Objective: To explore the stability of resistant phenotypes and changes of clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated (Cas) gene system on four Shigella strains in the absence of antibiotics. Methods: Four clinical isolated Shigella strains that resistant to different antibiotics were consecutive passaged for 90 times without antibiotics. Agar dilution method was used to determine the minimum inhibitory concentration of Shigella strains. After sequence analysis with PCR, CRISPR Finder and Clustal X 2.1 were applied to identify the changes of CRISPR loci in the Shigella strains. Results: After the consecutive transfer of 90 generations, sensitivity to certain antibiotics of four Shigella strains with different drug resistant spectrums increased. Mel-sf1998024/zz resistance to ampicillin, cephalexin, cefotaxime, chloramphenicol decreased, mel-s2014026/sx resistance to norfloxacin, trimethoprim decreased, mel-sf2004004/sx drug resistance to ampicillin, cefuroxime, cefotaxime, chloramphenicol, trimethoprim decreased and mel-sf2013004/bj resistance to chloramphenicol decreased. The spacer of which matched gene codes Cas and its upstream repeat in 3'end of CRISPR3 got lost in mel-sf1998024/zz and mel-sf2013004/bj. Conclusions: Shigella strains could reduce or lose their resistance to some antibiotics after consecutive transfers, without the interference of antibiotics. CRISPR3 locus had dynamic spacers in Shigella strains while CRISPR3 locus and cas genes might have been co-evolved.

  12. Epidemic shigella dysentery in children in northern KwaZulu-Natal

    African Journals Online (AJOL)

    sex, clinical features, complications and outcome. Results. Between February and December 1995, 158 cases of bloody diarrhoea were admitted, compared with. 6 the previous year. Shigella dysenteriae type I, resistant to ampicillin, tetraCYCline, chloramphenicol, trimethoprim and sulphamethoxazole, but susceptible to ...

  13. Resistencia antimicrobiana de Salmonella, Shigella y Vibrio cholerae: Perú 1997-2002

    Directory of Open Access Journals (Sweden)

    Isabel Arias B

    2004-10-01

    Full Text Available La resistencia a los antimicrobianos es un problema de salud pública, en este caso se presentan los resultados de la resistencia antimicrobiana de Salmonella, Shigella y Vibrio cholerae entre los años 1997 y 2002 de las cepas confirmadas por el Instituto Nacional de Salud, procedentes de los laboratorios referenciales regionales de las diferentes direcciones de salud del Perú. La confirmación se realizó mediante bioquímica y serotipificación; para las pruebas de sensibilidad se utilizó el método de disco difusión. Se evaluaron un total de 542 cepas de Salmonella, 1034 de Shigella y 603 de Vibrio cholerae. La resistencia de Shigella frente a ampicilina muestra un promedio de 74,4% durante los 6 años; cloramfenicol con 65,9 %, cotrimoxazol con 72,2 %. En Salmonella se observa un promedio de 3,46 % para ampicilina; 2,83 % para cloranfenicol; en gentamicina 3,9 % y cotrimoxazol 1,1. V. Cholerae entre 1997 y 1999 mostraron promedios de resistencia de 19 % a cotrimoxazol, 12,1 % a tetraciclina y 10,2 % a ampicilina. A partir del año 2000, no se reportaron casos, por lo que se recibieron pocas cepas de esta especie. Se evidencia el problema de resistencia de Shigella frente a ampicilina, cloramfenicol y cotrimoxazol.

  14. [Susceptibility to azithromycin and other antibiotics in recent isolates of Salmonella, Shigella and Yersinia].

    Science.gov (United States)

    Martín-Pozo, Angeles; Arana, David M; Fuentes, Miriam; Alós, Juan-Ignacio

    2014-01-01

    Azithromycin represents an alternative option to treat bacterial diarrhea when the antibiotic therapy is indicated. Little is known regarding the susceptibility to azithromycin in enteropathogens in Spain. The MICs of azithromycin were determined by E-test against Salmonella non-typhi (SNT), Shigella and Yersinia isolates collected over the last three years (2010-2012). In addition, the susceptibility to other antibiotics usually used to treat gastrointestinal diseases was determined in these isolates by using a microdilution method. A total of 139 strains of SNT, Shigella and Yersinia were studied. All of them, except one strain, had a MIC≤16mg/L of azithromycin. In the adult population, 14.7% and 40.6% of SNT and Shigella isolates, respectively, were resistant to at least 2 of following antibiotics: amoxicillin, trimethoprim-sulfamethoxazole and ciprofloxacin. In the pediatric population, 10% of SNT clinical isolates and 28.6% (2/7) of Shigella isolates were resistant to amoxicillin and trimethoprim-sulfamethoxazole. In our experience, azithromycin would be a useful antibiotic alternative to treat bacterial diarrhea. Copyright © 2013 Elsevier España, S.L. y Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.

  15. A real-time loop-mediated isothermal amplification assay for rapid detection of Shigella species.

    Science.gov (United States)

    Liew, P S; Teh, C S J; Lau, Y L; Thong, K L

    2014-12-01

    Shigellosis is a foodborne illness caused by the genus Shigella and is an important global health issue. The development of effective techniques for rapid detection of this pathogen is essential for breaking the chain of transmission. Therefore, we have developed a novel loop-mediated isothermal amplification (LAMP) assay targeting the invasion plasmid antigen H (ipaH) gene to rapidly detect Shigella species. This assay could be performed in 90 min at an optimal temperature of 64ºC, with endpoint results visualized directly. Notably, the method was found to be more sensitive than conventional PCR. Indeed, the detection limit for the LAMP assay on pure bacterial cultures was 5.9 x 10(5) CFU/ml, while PCR displayed a limit of 5.9 x 10(7) CFU/ml. In spiked lettuce samples, the sensitivity of the LAMP assay was 3.6 x 10(4) CFU/g, whereas PCR was 3.6 x 10(5) CFU/g. Overall, the assay accurately identified 32 Shigella spp. with one enteroinvasive Escherichia coli displaying positive reaction while the remaining 32 non-Shigella strains tested were negative.

  16. Shigella-specific IgA in saliva of children with bacillary dysentery

    NARCIS (Netherlands)

    Schultsz, C.; Qadri, F.; Hossain, S. A.; Ahmed, F.; Ciznar, I.

    1992-01-01

    To study the secretory immune response after Shigella infection, the anti-lipopolysaccharide and anti-Shiga-toxin response in saliva, obtained from children with confirmed shigellosis and healthy children, were determined by enzyme-linked immunosorbent assay and by Western blot. Children with

  17. Socioeconomic Determinants of Ciprofloxacin-Resistant Shigella Infections in Bangladeshi Children

    Directory of Open Access Journals (Sweden)

    Randon J. Gruninger

    2017-03-01

    Full Text Available Background: Shigella species (spp. are a leading cause of moderate to severe diarrhea in children worldwide. The recent emergence of quinolone-resistant Shigella spp. gives cause for concern, and South Asia has been identified as a reservoir for global spread. The influence of socioeconomic status on antimicrobial resistance in developing countries, such as those in South Asia, remains unknown. Methods: We used data collected from 2009 to 2014 from a hospital specializing in the treatment of diarrhea in Dhaka, Bangladesh, to determine the relationship between ciprofloxacin-resistant Shigella spp. isolates and measures of socioeconomic status in Bangladeshi children less than 5 years of age. Results: We found 2.7% (230/8, 672 of children who presented with diarrhea had Shigella spp. isolated from their stool, and 50% (115/230 had resistance to ciprofloxacin. Using multivariable logistic regression analysis, we found that children from families where the father’s income was in the highest quintile had significantly higher odds of having ciprofloxacin-resistant Shigella spp. compared to children in the lowest quintile (OR = 6.1, CI 1.9-19. Factors protective against the development of resistance included access to improved sanitation (OR = 0.27, CI 0.11-0.7, and improved water sources (OR = 0.48, CI 0.25-0.92. We did not find a relationship between ciprofloxacin resistance and other proxies for socioeconomic status, including the presence of animals in the home, nutritional status, paternal education level, and the number of family members in the home. Conclusions: Although the associations between wealth and antimicrobial resistance are not fully understood, possible explanations include increased access and use of antibiotics, greater access to healthcare facilities and thus resistant pathogens, or greater consumption of commercially produced foods prepared with antibiotics.

  18. Detergent Isolation Stabilizes and Activates the Shigella Type III Secretion System Translocator Protein IpaC.

    Science.gov (United States)

    Bernard, Abram R; Duarte, Shari M; Kumar, Prashant; Dickenson, Nicholas E

    2016-07-01

    Shigella rely on a type III secretion system as the primary virulence factor for invasion and colonization of human hosts. Although there are an estimated 90 million Shigella infections, annually responsible for more than 100,000 deaths worldwide, challenges isolating and stabilizing many type III secretion system proteins have prevented a full understanding of the Shigella invasion mechanism and additionally slowed progress toward a much needed Shigella vaccine. Here, we show that the non-denaturing zwitterionic detergent N, N-dimethyldodecylamine N-oxide (LDAO) and non-ionic detergent n-octyl-oligo-oxyethylene efficiently isolated the hydrophobic Shigella translocator protein IpaC from the co-purified IpaC/IpgC chaperone-bound complex. Both detergents resulted in monomeric IpaC that exhibits strong membrane binding and lysis characteristics while the chaperone-bound complex does not, suggesting that the stabilizing detergents provide a means of following IpaC "activation" in vitro. Additionally, biophysical characterization found that LDAO provides significant thermal and temporal stability to IpaC, protecting it for several days at room temperature and brief exposure to temperatures reaching 90°C. In summary, this work identified and characterized conditions that provide stable, membrane active IpaC, providing insight into key interactions with membranes and laying a strong foundation for future vaccine formulation studies taking advantage of the native immunogenicity of IpaC and the stability provided by LDAO. Copyright © 2016 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  19. ORF Alignment: NC_004851 [GENIUS II[Archive

    Lifescience Database Archive (English)

    Full Text Available NC_004851 gi|31983537 >1mwmA 1 315 2 316 e-100 ... ref|NP_858328.1| plasmid stable inheritance... protein [Shigella flexneri 2a str. 301] ... gb|AAL72301.1| plasmid stable inheritance prote...7.1| plasmid stable ... inheritance protein [Shigella flexneri] ref|NP_085...361.1| ... plasmid stable inheritance protein [Shigella flexneri] ... Length = 315 ... Query: 2 ...

  20. ORF Alignment: NC_004337 [GENIUS II[Archive

    Lifescience Database Archive (English)

    Full Text Available NC_004337 gi|56479866 >1u07A 1 90 153 242 2e-32 ... ref|NP_707161.2| membrane protein, energy... transducer [Shigella flexneri 2a str. 301] ... gb|AAN42868.2| membrane protein, energy trans...ducer ... [Shigella flexneri 2a str. 301] ref|NP_836946.1| ... membrane protein, energy transd...ucer [Shigella flexneri ... 2a str. 2457T] gb|AAP16753.1| membrane protein, energy

  1. ORF Alignment: NC_002695 [GENIUS II[Archive

    Lifescience Database Archive (English)

    Full Text Available NC_002695 gi|15831006 >1u07A 1 90 153 242 2e-32 ... ref|NP_707161.2| membrane protein, energy... transducer [Shigella flexneri 2a str. 301] ... gb|AAN42868.2| membrane protein, energy trans...ducer ... [Shigella flexneri 2a str. 301] ref|NP_836946.1| ... membrane protein, energy transd...ucer [Shigella flexneri ... 2a str. 2457T] gb|AAP16753.1| membrane protein, energy

  2. ORF Alignment: NC_004741 [GENIUS II[Archive

    Lifescience Database Archive (English)

    Full Text Available NC_004741 gi|30062775 >1u07A 1 90 153 242 2e-32 ... ref|NP_707161.2| membrane protein, energy... transducer [Shigella flexneri 2a str. 301] ... gb|AAN42868.2| membrane protein, energy trans...ducer ... [Shigella flexneri 2a str. 301] ref|NP_836946.1| ... membrane protein, energy transd...ucer [Shigella flexneri ... 2a str. 2457T] gb|AAP16753.1| membrane protein, energy

  3. ORF Alignment: NC_000913 [GENIUS II[Archive

    Lifescience Database Archive (English)

    Full Text Available NC_000913 gi|16129213 >1u07A 1 90 153 242 2e-32 ... ref|NP_707161.2| membrane protein, energy... transducer [Shigella flexneri 2a str. 301] ... gb|AAN42868.2| membrane protein, energy trans...ducer ... [Shigella flexneri 2a str. 301] ref|NP_836946.1| ... membrane protein, energy transd...ucer [Shigella flexneri ... 2a str. 2457T] gb|AAP16753.1| membrane protein, energy

  4. ORF Alignment: NC_004431 [GENIUS II[Archive

    Lifescience Database Archive (English)

    Full Text Available NC_004431 gi|26247582 >1u07A 1 90 153 242 2e-32 ... ref|NP_707161.2| membrane protein, energy... transducer [Shigella flexneri 2a str. 301] ... gb|AAN42868.2| membrane protein, energy trans...ducer ... [Shigella flexneri 2a str. 301] ref|NP_836946.1| ... membrane protein, energy transd...ucer [Shigella flexneri ... 2a str. 2457T] gb|AAP16753.1| membrane protein, energy

  5. Circulating Gut-Homing (α4β7+) Plasmablast Responses against Shigella Surface Protein Antigens among Hospitalized Patients with Diarrhea.

    Science.gov (United States)

    Sinha, Anuradha; Dey, Ayan; Saletti, Giulietta; Samanta, Pradip; Chakraborty, Partha Sarathi; Bhattacharya, M K; Ghosh, Santanu; Ramamurthy, T; Kim, Jae-Ouk; Yang, Jae Seung; Kim, Dong Wook; Czerkinsky, Cecil; Nandy, Ranjan K

    2016-07-01

    Developing countries are burdened with Shigella diarrhea. Understanding mucosal immune responses associated with natural Shigella infection is important to identify potential correlates of protection and, as such, to design effective vaccines. We performed a comparative analysis of circulating mucosal plasmablasts producing specific antibodies against highly conserved invasive plasmid antigens (IpaC, IpaD20, and IpaD120) and two recently identified surface protein antigens, pan-Shigella surface protein antigen 1 (PSSP1) and PSSP2, common to all virulent Shigella strains. We examined blood and stool specimens from 37 diarrheal patients admitted to the Infectious Diseases & Beliaghata General Hospital, Kolkata, India. The etiological agent of diarrhea was investigated in stool specimens by microbiological methods and real-time PCR. Gut-homing (α4β7 (+)) antibody-secreting cells (ASCs) were isolated from patient blood by means of combined magnetic cell sorting and two-color enzyme-linked immunosorbent spot (ELISPOT) assay. Overall, 57% (21 of 37) and 65% (24 of 37) of the patients were positive for Shigella infection by microbiological and real-time PCR assays, respectively. The frequency of α4β7 (+) IgG ASC responders against Ipas was higher than that observed against PSSP1 or PSSP2, regardless of the Shigella serotype isolated from these patients. Thus, α4β7 (+) ASC responses to Ipas may be considered an indirect marker of Shigella infection. The apparent weakness of ASC responses to PSSP1 is consistent with the lack of cross-protection induced by natural Shigella infection. The finding that ASC responses to IpaD develop in patients with recent-onset shigellosis indicates that such responses may not be protective or may wane too rapidly and/or be of insufficient magnitude. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  6. Ultrastructural Histopathology of Vervet Monkey Colonic Epithelium After In Vitro Exposure to Cell-free Supernatants of Shigella Cultures

    OpenAIRE

    Hill, R. R.; Collins, N. E.; Cowley, H. M.

    2011-01-01

    The full dysentery syndrome of human shigellosis is often preceded by a transient diarrhoea that may be induced by bacterial extracellular products before invasion of the colonic mucosa and development of subsequent pathology. To examine this hypothesis, we studied the effects of cell-free cultures of Shigella sp. on the ultrastructure of monkey colonic epithelium in vitro. Clinical isolates of shigella strains were grown in a niche-simulating medium. Sheets of colon wall collected from verve...

  7. Differential regulation of caspase-1 activation, pyroptosis, and autophagy via Ipaf and ASC in Shigella-infected macrophages.

    Directory of Open Access Journals (Sweden)

    Toshihiko Suzuki

    2007-08-01

    Full Text Available Shigella infection, the cause of bacillary dysentery, induces caspase-1 activation and cell death in macrophages, but the precise mechanisms of this activation remain poorly understood. We demonstrate here that caspase-1 activation and IL-1beta processing induced by Shigella are mediated through Ipaf, a cytosolic pattern-recognition receptor of the nucleotide-binding oligomerization domain (NOD-like receptor (NLR family, and the adaptor protein apoptosis-associated speck-like protein containing a C-terminal caspase recruitment domain (ASC. We also show that Ipaf was critical for pyroptosis, a specialized form of caspase-1-dependent cell death induced in macrophages by bacterial infection, whereas ASC was dispensable. Unlike that observed in Salmonella and Legionella, caspase-1 activation induced by Shigella infection was independent of flagellin. Notably, infection of macrophages with Shigella induced autophagy, which was dramatically increased by the absence of caspase-1 or Ipaf, but not ASC. Autophagy induced by Shigella required an intact bacterial type III secretion system but not VirG protein, a bacterial factor required for autophagy in epithelial-infected cells. Treatment of macrophages with 3-methyladenine, an inhibitor of autophagy, enhanced pyroptosis induced by Shigella infection, suggesting that autophagy protects infected macrophages from pyroptosis. Thus, Ipaf plays a critical role in caspase-1 activation induced by Shigella independently of flagellin. Furthermore, the absence of Ipaf or caspase-1, but not ASC, regulates pyroptosis and the induction of autophagy in Shigella-infected macrophages, providing a novel function for NLR proteins in bacterial-host interactions.

  8. Spatio-temporal trends and risk factors for Shigella from 2001 to 2011 in Jiangsu Province, People's Republic of China.

    Directory of Open Access Journals (Sweden)

    Fenyang Tang

    Full Text Available This study aimed to describe the spatial and temporal trends of Shigella incidence rates in Jiangsu Province, People's Republic of China. It also intended to explore complex risk modes facilitating Shigella transmission.County-level incidence rates were obtained for analysis using geographic information system (GIS tools. Trend surface and incidence maps were established to describe geographic distributions. Spatio-temporal cluster analysis and autocorrelation analysis were used for detecting clusters. Based on the number of monthly Shigella cases, an autoregressive integrated moving average (ARIMA model successfully established a time series model. A spatial correlation analysis and a case-control study were conducted to identify risk factors contributing to Shigella transmissions.The far southwestern and northwestern areas of Jiangsu were the most infected. A cluster was detected in southwestern Jiangsu (LLR = 11674.74, P<0.001. The time series model was established as ARIMA (1, 12, 0, which predicted well for cases from August to December, 2011. Highways and water sources potentially caused spatial variation in Shigella development in Jiangsu. The case-control study confirmed not washing hands before dinner (OR = 3.64 and not having access to a safe water source (OR = 2.04 as the main causes of Shigella in Jiangsu Province.Improvement of sanitation and hygiene should be strengthened in economically developed counties, while access to a safe water supply in impoverished areas should be increased at the same time.

  9. Spatio-temporal trends and risk factors for Shigella from 2001 to 2011 in Jiangsu Province, People's Republic of China.

    Science.gov (United States)

    Tang, Fenyang; Cheng, Yuejia; Bao, Changjun; Hu, Jianli; Liu, Wendong; Liang, Qi; Wu, Ying; Norris, Jessie; Peng, Zhihang; Yu, Rongbin; Shen, Hongbing; Chen, Feng

    2014-01-01

    This study aimed to describe the spatial and temporal trends of Shigella incidence rates in Jiangsu Province, People's Republic of China. It also intended to explore complex risk modes facilitating Shigella transmission. County-level incidence rates were obtained for analysis using geographic information system (GIS) tools. Trend surface and incidence maps were established to describe geographic distributions. Spatio-temporal cluster analysis and autocorrelation analysis were used for detecting clusters. Based on the number of monthly Shigella cases, an autoregressive integrated moving average (ARIMA) model successfully established a time series model. A spatial correlation analysis and a case-control study were conducted to identify risk factors contributing to Shigella transmissions. The far southwestern and northwestern areas of Jiangsu were the most infected. A cluster was detected in southwestern Jiangsu (LLR = 11674.74, PHighways and water sources potentially caused spatial variation in Shigella development in Jiangsu. The case-control study confirmed not washing hands before dinner (OR = 3.64) and not having access to a safe water source (OR = 2.04) as the main causes of Shigella in Jiangsu Province. Improvement of sanitation and hygiene should be strengthened in economically developed counties, while access to a safe water supply in impoverished areas should be increased at the same time.

  10. ORF Alignment: NC_004741 [GENIUS II[Archive

    Lifescience Database Archive (English)

    Full Text Available NC_004741 gi|30062733 >1iwmA 1 177 31 207 2e-76 ... ref|NP_707118.1| carrier of lipoproteins... to outer membrane [Shigella flexneri 2a ... str. 301] gb|AAN42825.1| carrier of lipoproteins ...to ... outer membrane [Shigella flexneri 2a str. 301] ... ref|NP_836904.1| carrier of lipoproteins...|AAP16711.1| carrier of lipoproteins to outer membrane ... [Shigella flexneri 2a str. 2457T] gb|AAA24... to outer ... membrane [Shigella flexneri 2a str. 2457T] ... gb

  11. ORF Alignment: NC_002655 [GENIUS II[Archive

    Lifescience Database Archive (English)

    Full Text Available NC_002655 gi|15801438 >1iwmA 1 177 31 207 2e-76 ... ref|NP_707118.1| carrier of lipoproteins... to outer membrane [Shigella flexneri 2a ... str. 301] gb|AAN42825.1| carrier of lipoproteins ...to ... outer membrane [Shigella flexneri 2a str. 301] ... ref|NP_836904.1| carrier of lipoproteins...|AAP16711.1| carrier of lipoproteins to outer membrane ... [Shigella flexneri 2a str. 2457T] gb|AAA24... to outer ... membrane [Shigella flexneri 2a str. 2457T] ... gb

  12. ORF Alignment: NC_000913 [GENIUS II[Archive

    Lifescience Database Archive (English)

    Full Text Available NC_000913 gi|16129172 >1iwmA 1 177 31 207 2e-76 ... ref|NP_707118.1| carrier of lipoproteins... to outer membrane [Shigella flexneri 2a ... str. 301] gb|AAN42825.1| carrier of lipoproteins ...to ... outer membrane [Shigella flexneri 2a str. 301] ... ref|NP_836904.1| carrier of lipoproteins...|AAP16711.1| carrier of lipoproteins to outer membrane ... [Shigella flexneri 2a str. 2457T] gb|AAA24... to outer ... membrane [Shigella flexneri 2a str. 2457T] ... gb

  13. ORF Alignment: NC_004337 [GENIUS II[Archive

    Lifescience Database Archive (English)

    Full Text Available NC_004337 gi|24112608 >1iwmA 1 177 31 207 2e-76 ... ref|NP_707118.1| carrier of lipoproteins... to outer membrane [Shigella flexneri 2a ... str. 301] gb|AAN42825.1| carrier of lipoproteins ...to ... outer membrane [Shigella flexneri 2a str. 301] ... ref|NP_836904.1| carrier of lipoproteins...|AAP16711.1| carrier of lipoproteins to outer membrane ... [Shigella flexneri 2a str. 2457T] gb|AAA24... to outer ... membrane [Shigella flexneri 2a str. 2457T] ... gb

  14. ORF Alignment: NC_002695 [GENIUS II[Archive

    Lifescience Database Archive (English)

    Full Text Available NC_002695 gi|15830968 >1iwmA 1 177 31 207 2e-76 ... ref|NP_707118.1| carrier of lipoproteins... to outer membrane [Shigella flexneri 2a ... str. 301] gb|AAN42825.1| carrier of lipoproteins ...to ... outer membrane [Shigella flexneri 2a str. 301] ... ref|NP_836904.1| carrier of lipoproteins...|AAP16711.1| carrier of lipoproteins to outer membrane ... [Shigella flexneri 2a str. 2457T] gb|AAA24... to outer ... membrane [Shigella flexneri 2a str. 2457T] ... gb

  15. Shigella sonnei Vaccine Candidates WRSs2 and WRSs3 Are as Immunogenic as WRSS1, a Clinically Tested Vaccine Candidate, in a Primate Model of Infection

    Science.gov (United States)

    2011-01-01

    Experiments in rabbit ileal loops and in rhesus monkeys have shown that shigellae are initially taken up by antigen sampling microfold (M) cells that are...2011) – Table 1 Shigella antigen-specific immune responses and colonization in rhesus monkeys after nasogastric administration of WRSS1, WRSs2...the respective antigens. 3.3. Mucosal responses in rhesus monkeys The mucosal immune response to Shigella LPS, and Invaplex- 50 antigens are summarized

  16. Decreasing Shigellosis-related Deaths without Shigella spp.–specific Interventions, Asia

    Science.gov (United States)

    Bardhan, Pradip; Faruque, A.S.G.; Naheed, Aliya

    2010-01-01

    In 1999, a review of the literature for 1966–1997 suggested that ≈1.1 million persons die annually of shigellosis, including ≈880,000 in Asia. Our recent review of the literature for 1990–2009 indicates that ≈125 million shigellosis cases occur annually in Asia, of which ≈14,000 are fatal. This estimate for illnesses is similar to the earlier estimate, but the number of deaths is 98% lower; that is, the lower estimate of deaths is associated with markedly reduced case-fatality rates rather than fewer cases. Shigella spp.–related deaths decreased substantially during a period without Shigella spp.–specific interventions. We speculate that nonspecific interventions, e.g., measles vaccination, vitamin A supplementation, and improved nutrition, may have led to the reduced number of shigellosis-related deaths. PMID:21029529

  17. Decrease in shigellosis-related deaths without Shigella spp.-specific interventions, Asia.

    Science.gov (United States)

    Bardhan, Pradip; Faruque, A S G; Naheed, Aliya; Sack, David A

    2010-11-01

    In 1999, a review of the literature for 1966-1997 suggested that ≈1.1 million persons die annually of shigellosis, including ≈880,000 in Asia. Our recent review of the literature for 1990-2009 indicates that ≈125 million shigellosis cases occur annually in Asia, of which ≈14,000 are fatal. This estimate for illnesses is similar to the earlier estimate, but the number of deaths is 98% lower; that is, the lower estimate of deaths is associated with markedly reduced case-fatality rates rather than fewer cases. Shigella spp.-related deaths decreased substantially during a period without Shigella spp.-specific interventions. We speculate that nonspecific interventions, e.g., measles vaccination, vitamin A supplementation, and improved nutrition, may have led to the reduced number of shigellosis-related deaths.

  18. Salmonella serotypeTyphi, Shigella, and intestinal parasites among food handlers at Bahir Dar University, Ethiopia.

    Science.gov (United States)

    Abera, Bayeh; Yitayew, Gashaw; Amare, Hiwot

    2016-02-28

    Food handlers play a major role in the transmission of Salmonella serotype Typhi (S. Typhi), Shigella, and intestinal parasites. This study was conducted to determine the prevalence of S. Typhi, Shigella, and intestinal parasites among food handlers at Bahir Dar University, Ethiopia. A cross-sectional study was conducted in June 2014. Stool samples from 410 food handlers were examined for bacterial pathogens and parasites. Pearson's Chi-square test, Fisher's exact test, and bivariate and multivariate logistic regression analyses were used where appropriate. The prevalence of S. Typhi, Shigella, and intestinal parasites among food handlers was 11 (2.7%), 5 (1.2%), and 53 (12.9%), respectively. Among eight intestinal parasites identified, the two most prevalent intestinal parasites were hookworm 26 (6.3%) and G. lamblia 13 (3.1%). Male food handlers were more likely to be positive than were female food handlers for S. Typhi and intestinal parasites. Furthermore, food handlers who had a history of regular medical checkups were less infected with intestinal parasites. Being male (AOR: 2.1, 95% CI: 1.2, 4.4) and not attending medical checkups (AOR: 2.9, 95% CI: 1.4, 6.1) were independent predictors of intestinal parasitic infection in food handlers. Male food handlers were reluctant to have regular parasitological examinations. There was a high proportion of food handlers with S. Typhi, Shigella, and intestinal parasites in their faces. Special emphasis should be placed on S. Typhicarriers and male food handlers. Education and periodical medical checkups for intestinal parasites and S. Typhi should be considered as intervention measures.

  19. Travel Destinations and Sexual Behavior as Indicators of Antibiotic Resistant Shigella Strains--Victoria, Australia.

    Science.gov (United States)

    Lane, Courtney R; Sutton, Brett; Valcanis, Mary; Kirk, Martyn; Walker, Cathryn; Lalor, Karin; Stephens, Nicola

    2016-03-15

    Knowledge of relationships between antibiotic susceptibility of Shigella isolates and travel destination or other risk factors can assist clinicians in determining appropriate antibiotic therapy prior to susceptibility testing. We describe relationships between resistance patterns and risk factors for acquisition in Shigella isolates using routinely collected data for notified cases of shigellosis between 2008 and 2012 in Victoria, Australia. We included all shigellosis patients notified during the study period, where Shigella isolates were tested for antimicrobial sensitivity using Clinical and Laboratory Standards Institute breakpoints. Cases were interviewed to collect data on risk factors, including recent travel. Data were analyzed using Stata 13.1 to examine associations between risk factors and resistant strains. Of the 500 cases of shigellosis, 249 were associated with overseas travel and 210 were locally acquired. Forty-six of 51 isolates of Indian origin displayed decreased susceptibility or resistance to ciprofloxacin. All isolates of Indonesian origin were susceptible to ciprofloxacin. Twenty-six travel-related isolates were resistant to all tested oral antimicrobials. Male-to-male sexual contact was the primary risk factor for 80% (120/150) of locally acquired infections among adult males, characterized by distinct periodic Shigella sonnei outbreaks. Clinicians should consider travel destination as a marker for resistance to common antimicrobials in returning travelers, where severe disease requires empirical treatment prior to receipt of individual sensitivity testing results. Repeated outbreaks of locally acquired shigellosis among men who have sex with men highlight the importance of prevention and control measures in this high-risk group. © The Author 2015. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

  20. Development of an Aotus nancymaae Model for Shigella Vaccine Immunogenicity and Efficacy Studies

    OpenAIRE

    Gregory, Michael; Kaminski, Robert W.; Lugo-Roman, Luis A.; Galvez Carrillo, Hugo; Tilley, Drake Hamilton; Baldeviano, Christian; Simons, Mark P.; Reynolds, Nathanael D.; Ranallo, Ryan T.; Suvarnapunya, Akamol E.; Venkatesan, Malabi M.; Oaks, Edwin V.

    2014-01-01

    Several animal models exist to evaluate the immunogenicity and protective efficacy of candidate Shigella vaccines. The two most widely used nonprimate models for vaccine development include a murine pulmonary challenge model and a guinea pig keratoconjunctivitis model. Nonhuman primate models exhibit clinical features and gross and microscopic colonic lesions that mimic those induced in human shigellosis. Challenge models for enterotoxigenic Escherichia coli (ETEC) and Campylobacter spp. have...

  1. The multifaceted activity of the VirF regulatory protein in the Shigella lifestyle

    Directory of Open Access Journals (Sweden)

    Maria Letizia Di Martino

    2016-09-01

    Full Text Available Shigella is a highly adapted human pathogen, mainly found in the developing world and causing a severe enteric syndrome. The highly sophisticated infectious strategy of Shigella banks on the capacity to invade the intestinal epithelial barrier and cause its inflammatory destruction. The cellular pathogenesis and clinical presentation of shigellosis are the sum of the complex action of a large number of bacterial virulence factors mainly located on a large virulence plasmid (pINV. The expression of pINV genes is controlled by multiple environmental stimuli through a regulatory cascade involving proteins and sRNAs encoded by both the pINV and the chromosome. The primary regulator of the virulence phenotype is VirF, a DNA-binding protein belonging to the AraC family of transcriptional regulators. The virF gene, located on the pINV, is expressed only within the host, mainly in response to the temperature transition occurring when the bacterium transits from the outer environment to the intestinal milieu. VirF then acts as anti-H-NS protein and directly activates the icsA and virB genes, triggering the full expression of the invasion program of Shigella. In this review we will focus on the structure of VirF, on its sophisticated regulation, and on its role as major player in the path leading from the non invasive to the invasive phenotype of Shigella. We will address also the involvement of VirF in mechanisms aimed at withstanding adverse conditions inside the host, indicating that this protein is emerging as a global regulator whose action is not limited to virulence systems. Finally, we will discuss recent observations conferring VirF the potential of a novel antibacterial target for shigellosis.

  2. Portable evanescent wave fiber biosensor for highly sensitive detection of Shigella

    Science.gov (United States)

    Xiao, Rui; Rong, Zhen; Long, Feng; Liu, Qiqi

    2014-11-01

    A portable evanescent wave fiber biosensor was developed to achieve the rapid and highly sensitive detection of Shigella. In this study, a DNA probe was covalently immobilized onto fiber-optic biosensors that can hybridize with a fluorescently labeled complementary DNA. The sensitivity of detection for synthesized oligonucleotides can reach 10-10 M. The surface of the sensor can be regenerated with 0.5% sodium dodecyl sulfate solution (pH 1.9) for over 30 times without significant deterioration of performance. The total analysis time for a single sample, including the time for measurement and surface regeneration, was less than 6 min. We employed real-time polymerase chain reaction (PCR) and compared the results of both methods to investigate the actual Shigella DNA detection capability of the fiber-optic biosensor. The fiber-optic biosensor could detect as low as 102 colony-forming unit/mL Shigella. This finding was comparable with that by real-time PCR, which suggests that this method is a potential alternative to existing detection methods.

  3. An assessment of enterotoxigenic Escherichia coli and Shigella vaccine candidates for infants and children.

    Science.gov (United States)

    Walker, Richard I

    2015-02-18

    Despite improvements to water quality, sanitation, and the implementation of current prevention and treatment interventions, diarrhea remains a major cause of illness and death, especially among children less than five years of age in the developing world. Rotavirus vaccines have already begun making a real impact on diarrhea, but several more enteric vaccines will be necessary to achieve broader reductions of illness and death. Among the many causes of diarrheal disease, enterotoxigenic Escherichia coli (ETEC) and Shigella are the two most important bacterial pathogens for which there are no currently licensed vaccines. Vaccines against these two pathogens could greatly reduce the impact of disease caused by these infections. This review describes the approaches to ETEC and Shigella vaccines that are currently under development, including a range of both cellular and subunit approaches for each pathogen. In addition, the review discusses strategies for maximizing the potential benefit of these vaccines, which includes the feasibility of co-administration, consolidation, and combination of vaccine candidates, as well as issues related to effective administration of enteric vaccines to infants. Recent impact studies indicate that ETEC and Shigella vaccines could significantly benefit global public health. Either vaccine, particularly if they could be combined together or with another enteric vaccine, would be an extremely valuable tool for saving lives and promoting the health of infants and children in the developing world, as well as potentially providing protection to travelers and military personnel visiting endemic areas. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. Sibling sRNA RyfA1 Influences Shigella dysenteriae Pathogenesis

    Directory of Open Access Journals (Sweden)

    Megan E. Fris

    2017-01-01

    Full Text Available Small regulatory RNAs (sRNAs of Shigella dysenteriae and other pathogens are vital for the regulation of virulence-associated genes and processes. Here, we characterize RyfA1, one member of a sibling pair of sRNAs produced by S. dysenteriae. Unlike its nearly identical sibling molecule, RyfA2, predicted to be encoded almost exclusively by non-pathogenic species, the presence of a gene encoding RyfA1, or a RyfA1-like molecule, is strongly correlated with virulence in a variety of enteropathogens. In S. dysenteriae, the overproduction of RyfA1 negatively impacts the virulence-associated process of cell-to-cell spread as well as the expression of ompC, a gene encoding a major outer membrane protein important for the pathogenesis of Shigella. Interestingly, the production of RyfA1 is controlled by a second sRNA, here termed RyfB1, the first incidence of one regulatory small RNA controlling another in S. dysenteriae or any Shigella species.

  5. Evaluation of an intragastric challenge model for Shigella dysenteriae 1 in rhesus monkeys (Macaca mulatta) for the pre-clinical assessment of Shigella vaccine formulations.

    Science.gov (United States)

    Islam, Dilara; Ruamsap, Nattaya; Khantapura, Patchariya; Aksomboon, Ajchara; Srijan, Apichai; Wongstitwilairoong, Boonchai; Bodhidatta, Ladaporn; Gettayacamin, Montip; Venkatesan, Malabi M; Mason, Carl J

    2014-06-01

    Shigellosis is a worldwide disease, characterized by abdominal pain, fever, vomiting, and the passage of blood- and mucus-streaked stools. Rhesus monkeys and other primates are the only animals that are naturally susceptible to shigellosis. A suitable animal model is required for the pre-clinical evaluation of vaccines candidates. In this study, the minimal dose of Shigella dysenteriae1 1617 strain required to produce dysentery in four of five (80% attack rate) monkeys using an escalating dose range for three groups [2 × 10(8) , 2 × 10(9) and 2 × 10(10) colony forming unit (CFU)] was determined. In addition, the monkeys were re-infected. The identified optimal challenge dose was 2 × 10(9) CFU; this dose elicited 60% protection in monkeys when they were re-challenged with a one log higher dose (2 × 10(10) CFU). The challenge dose, 2 × 10(10) CFU, produced severe dysentery in all monkeys, with one monkey dying within 24 h, elicited 100% protection when re-challenged with the same dose. All monkeys exhibited immune responses. This study concludes that the rhesus monkey model closely mimics the disease and immune response seen in humans and is a suitable animal model for the pre-clinical evaluation of Shigella vaccine candidates. Prior infection with the 1617 strain can protect monkeys against subsequent re-challenges with homologous strains. © 2013 The Authors. APMIS published by John Wiley & Sons Ltd.

  6. Identification and management of Shigella infection in children with diarrhoea: a systematic review and meta-analysis.

    Science.gov (United States)

    Tickell, Kirkby D; Brander, Rebecca L; Atlas, Hannah E; Pernica, Jeffrey M; Walson, Judd L; Pavlinac, Patricia B

    2017-12-01

    Shigella infections are a leading cause of diarrhoeal death among children in low-income and middle-income countries. WHO guidelines reserve antibiotics for treating children with dysentery. Reliance on dysentery for identification and management of Shigella infection might miss an opportunity to reduce Shigella-associated morbidity and mortality. We aimed to systematically review and evaluate Shigella-associated and dysentery-associated mortality, the diagnostic value of dysentery for the identification of Shigella infection, and the efficacy of antibiotics for children with Shigella or dysentery, or both. We did three systematic reviews (for mortality, diagnostic value, and antibiotic treatment of Shigella and dysentery), and meta-analyses where appropriate, of studies in resource-limited settings. We searched MEDLINE, Embase, and LILACS database for studies published before Jan 1, 2017, in English, French, and Spanish. We included studies of human beings with diarrhoea and accepted all study-specific definitions of dysentery. For the mortality and diagnostic value searches, we excluded studies that did not include an effect estimate or data necessary to calculate this estimate. The search for treatment included only randomised controlled trials that were done after Jan 1, 1980, and assessed antibiotics in children (aged Shigella. We extracted or calculated odds ratios (ORs) and 95% CIs for relative mortality and did random-effects meta-analysis to arrive at pooled ORs. We calculated 95% CIs assuming a binomial distribution and did random-effects meta-regression of log-transformed sensitivity and specificity estimates for diagnostic value. We assessed the heterogeneity of papers included in these meta-analyses using the I 2 statistic and evaluated publication bias using funnel plots. This review is registered with PROSPERO (CRD42017063896). 3649 papers were identified and 60 studies were included for analyses: 13 for mortality, 27 for diagnostic value, and 20 for

  7. Changing patterns and widening of antibiotic resistance in Shigella spp. over a decade (2000-2011), Andaman Islands, India.

    Science.gov (United States)

    Bhattacharya, D; Bhattacharya, H; Sayi, D S; Bharadwaj, A P; Singhania, M; Sugunan, A P; Roy, S

    2015-02-01

    This study is a part of the surveillance study on childhood diarrhoea in the Andaman and Nicobar Islands; here we report the drug resistance pattern of recent isolates of Shigella spp. (2006-2011) obtained as part of that study and compare it with that of Shigella isolates obtained earlier during 2000-2005. During 2006-2011, stool samples from paediatric diarrhoea patients were collected and processed for isolation and identification of Shigella spp. Susceptibility to 22 antimicrobial drugs was tested and minimum inhibitory concentrations were determined for third-generation cephalosporins, quinolones, amoxicillin-clavulanic acid combinations and gentamicin. A wide spectrum of antibiotic resistance was observed in the Shigella strains obtained during 2006-2011. The proportions of resistant strains showed an increase from 2000-2005 to 2006-2011 in 20/22 antibiotics tested. The number of drug resistance patterns increased from 13 in 2000-2005 to 43 in 2006-2011. Resistance to newer generation fluoroquinolones, third-generation cephalosporins and augmentin, which was not observed during 2000-2005, appeared during 2006-2011. The frequency of resistance in Shigella isolates has increased substantially between 2000-2006 and 2006-2011, with a wide spectrum of resistance. At present, the option for antimicrobial therapy in shigellosis in Andaman is limited to a small number of drugs.

  8. Quantification of viable but nonculturable Salmonella spp. and Shigella spp. during sludge anaerobic digestion and their reactivation during cake storage.

    Science.gov (United States)

    Fu, B; Jiang, Q; Liu, H-B; Liu, H

    2015-10-01

    The presence of viable but nonculturable (VBNC) bacterial pathogens which often fail to be detected by cultivation and can regain the cultivability if the living conditions improve were reported. The objective of this study was to determine the occurrence of VBNC Salmonella spp. and Shigella spp. in the biosolids during anaerobic digestion and its reactivation during the cake storage. The occurrence of VBNC Salmonella spp. and Shigella spp. during mesophilic, temperature-phased, thermophilic anaerobic digestion of sewage sludge and the subsequent storage were studied by RT-qPCR and most probable number (MPN) method. The VBNC incidence of Salmonella spp. and Shigella spp. during thermophilic digestion was four orders of magnitude higher than those of mesophilic digestion. Accordingly, higher resuscitation ratio of VBNC pathogens was also achieved in thermophilic digested sludge. As a result, the culturable Salmonella typhimurium contents in thermophilic digested sludge after cake storage were two orders of magnitude higher than mesophilic digestion. Both quantitative PCR and reverse transcription quantitative PCR assay results showed the two bacterial counting numbers remained stable throughout the cake storage. The results indicate that the increase in the culturable Salmonella spp. and Shigella spp. after centrifugal dewatering was attributed to the resuscitation from the VBNC state to the culturable state. Thermophilic anaerobic digestion mainly induced Salmonella spp. and Shigella spp. into VBNC state rather than killed them, suggesting that the biological safety of sewage sludge by temperature-phased anaerobic digestion should be carefully assessed. © 2015 The Society for Applied Microbiology.

  9. The use of comparative genomic hybridization to characterize genome dynamics and diversity among the serotypes of Shigella

    Directory of Open Access Journals (Sweden)

    Sun Meisheng

    2006-08-01

    Full Text Available Abstract Background Compelling evidence indicates that Shigella species, the etiologic agents of bacillary dysentery, as well as enteroinvasive Escherichia coli, are derived from multiple origins of Escherichia coli and form a single pathovar. To further understand the genome diversity and virulence evolution of Shigella, comparative genomic hybridization microarray analysis was employed to compare the gene content of E. coli K-12 with those of 43 Shigella strains from all lineages. Results For the 43 strains subjected to CGH microarray analyses, the common backbone of the Shigella genome was estimated to contain more than 1,900 open reading frames (ORFs, with a mean number of 726 undetectable ORFs. The mosaic distribution of absent regions indicated that insertions and/or deletions have led to the highly diversified genomes of pathogenic strains. Conclusion These results support the hypothesis that by gain and loss of functions, Shigella species became successful human pathogens through convergent evolution from diverse genomic backgrounds. Moreover, we also found many specific differences between different lineages, providing a window into understanding bacterial speciation and taxonomic relationships.

  10. MxiN Differentially Regulates Monomeric and Oligomeric Species of the Shigella Type Three Secretion System ATPase Spa47.

    Science.gov (United States)

    Case, Heather B; Dickenson, Nicholas E

    2018-04-17

    Shigella rely entirely on the action of a single type three secretion system (T3SS) to support cellular invasion of colonic epithelial cells and to circumvent host immune responses. The ATPase Spa47 resides at the base of the Shigella needle-like type three secretion apparatus (T3SA), supporting protein secretion through the apparatus and providing a likely means for native virulence regulation by Shigella and a much needed target for non-antibiotic therapeutics to treat Shigella infections. Here, we show that MxiN is a differential regulator of Spa47 and that its regulatory impact is determined by the oligomeric state of the Spa47 ATPase, with which it interacts. In vitro and in vivo characterization shows that interaction of MxiN with Spa47 requires the six N-terminal residues of Spa47 that are also necessary for stable Spa47 oligomer formation and activation. This interaction with MxiN negatively influences the activity of Spa47 oligomers while upregulating the ATPase activity of monomeric Spa47. Detailed kinetic analyses of monomeric and oligomeric Spa47 in the presence and absence of MxiN uncover additional mechanistic insights into the regulation of Spa47 by MxiN, suggesting that the MxiN/Spa47 species resulting from interaction with monomeric and oligomeric Spa47 are functionally distinct and that both could be involved in Shigella T3SS regulation. Uncovering regulation of Spa47 by MxiN addresses an important gap in the current understanding of how Shigella controls T3SA activity and provides the first description of differential T3SS ATPase regulation by a native T3SS protein.

  11. Investigating the Relatedness of Enteroinvasive Escherichia coli to Other E. coli and Shigella Isolates by Using Comparative Genomics.

    Science.gov (United States)

    Hazen, Tracy H; Leonard, Susan R; Lampel, Keith A; Lacher, David W; Maurelli, Anthony T; Rasko, David A

    2016-08-01

    Enteroinvasive Escherichia coli (EIEC) is a unique pathovar that has a pathogenic mechanism nearly indistinguishable from that of Shigella species. In contrast to isolates of the four Shigella species, which are widespread and can be frequent causes of human illness, EIEC causes far fewer reported illnesses each year. In this study, we analyzed the genome sequences of 20 EIEC isolates, including 14 first described in this study. Phylogenomic analysis of the EIEC genomes demonstrated that 17 of the isolates are present in three distinct lineages that contained only EIEC genomes, compared to reference genomes from each of the E. coli pathovars and Shigella species. Comparative genomic analysis identified genes that were unique to each of the three identified EIEC lineages. While many of the EIEC lineage-specific genes have unknown functions, those with predicted functions included a colicin and putative proteins involved in transcriptional regulation or carbohydrate metabolism. In silico detection of the Shigella virulence plasmid (pINV), which is essential for the invasion of host cells, demonstrated that a form of pINV was present in nearly all EIEC genomes, but the Mxi-Spa-Ipa region of the plasmid that encodes the invasion-associated proteins was absent from several of the EIEC isolates. The comparative genomic findings in this study support the hypothesis that multiple EIEC lineages have evolved independently from multiple distinct lineages of E. coli via the acquisition of the Shigella virulence plasmid and, in some cases, the Shigella pathogenicity islands. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  12. A new piece of the Shigella Pathogenicity puzzle: spermidine accumulation by silencing of the speG gene [corrected].

    Directory of Open Access Journals (Sweden)

    Marialuisa Barbagallo

    Full Text Available The genome of Shigella, a gram negative bacterium which is the causative agent of bacillary dysentery, shares strong homologies with that of its commensal ancestor, Escherichia coli. The acquisition, by lateral gene transfer, of a large plasmid carrying virulence determinants has been a crucial event in the evolution towards the pathogenic lifestyle and has been paralleled by the occurrence of mutations affecting genes, which negatively interfere with the expression of virulence factors. In this context, we have analysed to what extent the presence of the plasmid-encoded virF gene, the major activator of the Shigella regulon for invasive phenotype, has modified the transcriptional profile of E. coli. Combining results from transcriptome assays and comparative genome analyses we show that in E. coli VirF, besides being able to up-regulate several chromosomal genes, which potentially influence bacterial fitness within the host, also activates genes which have been lost by Shigella. We have focused our attention on the speG gene, which encodes spermidine acetyltransferase, an enzyme catalysing the conversion of spermidine into the physiologically inert acetylspermidine, since recent evidence stresses the involvement of polyamines in microbial pathogenesis. Through identification of diverse mutations, which prevent expression of a functional SpeG protein, we show that the speG gene has been silenced by convergent evolution and that its inactivation causes the marked increase of intracellular spermidine in all Shigella spp. This enhances the survival of Shigella under oxidative stress and allows it to better face the adverse conditions it encounters inside macrophage. This is supported by the outcome of infection assays performed in mouse peritoneal macrophages and of a competitive-infection assay on J774 macrophage cell culture. Our observations fully support the pathoadaptive nature of speG inactivation in Shigella and reveal that the accumulation

  13. The IpaC carboxyterminal effector domain mediates Src-dependent actin polymerization during Shigella invasion of epithelial cells.

    Directory of Open Access Journals (Sweden)

    Joëlle Mounier

    2009-01-01

    Full Text Available Shigella, the causative agent of bacillary dysentery, invades epithelial cells by locally reorganizing the actin cytoskeleton. Shigella invasion requires actin polymerization dependent on the Src tyrosine kinase and a functional bacterial type III secretion (T3S apparatus. Using dynamic as well as immunofluorescence microscopy, we show that the T3S translocon component IpaC allows the recruitment of the Src kinase required for actin polymerization at bacterial entry sites during the initial stages of Shigella entry. Src recruitment occurred at bacterial-cell contact sites independent of actin polymerization at the onset of the invasive process and was still observed in Shigella strains mutated for translocated T3S effectors of invasion. A Shigella strain with a polar mutation that expressed low levels of the translocator components IpaB and IpaC was fully proficient for Src recruitment and bacterial invasion. In contrast, a Shigella strain mutated in the IpaC carboxyterminal effector domain that was proficient for T3S effector translocation did not induce Src recruitment. Consistent with a direct role for IpaC in Src activation, cell incubation with the IpaC last 72 carboxyterminal residues fused to the Iota toxin Ia (IaC component that translocates into the cell cytosol upon binding to the Ib component led to Src-dependent ruffle formation. Strikingly, IaC also induced actin structures resembling bacterial entry foci that were enriched in activated Src and were inhibited by the Src inhibitor PP2. These results indicate that the IpaC effector domain determines Src-dependent actin polymerization and ruffle formation during bacterial invasion.

  14. Evolutionary Dynamics of Small RNAs in 27 Escherichia coli and Shigella Genomes

    Science.gov (United States)

    Skippington, Elizabeth; Ragan, Mark A.

    2012-01-01

    Small RNAs (sRNAs) are widespread in bacteria and play critical roles in regulating physiological processes. They are best characterized in Escherichia coli K-12 MG1655, where 83 sRNAs constitute nearly 2% of the gene complement. Most sRNAs act by base pairing with a target mRNA, modulating its translation and/or stability; many of these RNAs share only limited complementarity to their mRNA target, and require the chaperone Hfq to facilitate base pairing. Little is known about the evolutionary dynamics of bacterial sRNAs. Here, we apply phylogenetic and network analyses to investigate the evolutionary processes and principles that govern sRNA gene distribution in 27 E. coli and Shigella genomes. We identify core (encoded in all 27 genomes) and variable sRNAs; more than two-thirds of the E. coli K-12 MG1655 sRNAs are core, whereas the others show patterns of presence and absence that are principally due to genetic loss, not duplication or lateral genetic transfer. We present evidence that variable sRNAs are less tightly integrated into cellular genetic regulatory networks than are the core sRNAs, and that Hfq facilitates posttranscriptional cross talk between the E. coli–Shigella core and variable genomes. Finally, we present evidence that more than 80% of genes targeted by Hfq-associated core sRNAs have been transferred within the E. coli–Shigella clade, and that most of these genes have been transferred intact. These results suggest that Hfq and sRNAs help integrate laterally acquired genes into established regulatory networks. PMID:22223756

  15. Rupture, Invasion and Inflammatory Destruction of the Intestinal Barrier by Shigella: The Yin and Yang of Innate Immunity

    Directory of Open Access Journals (Sweden)

    Philippe J Sansonetti

    2006-01-01

    Full Text Available Shigella is a Gram-negative bacterial species of the family Enterobacteriaceae that causes bacillary dysentery in humans. This acute colitis reflects the capacity of the microorganism to disrupt, invade and cause the inflammatory destruction of the intestinal epithelium. The pathogenesis of the Shigella infection can be seen as a disruption of the homeostatic balance that protects the gut against inflammation in the presence of its commensal flora. This provides the unified view that enteroinvasive pathogens allow for the identification of key signalling molecules and pathways involved in the regulation of intestinal inflammation, and more generally, in the regulation of the innate and adaptive immune response.

  16. Recombinant Expression and Purification of the Shigella Translocator IpaB.

    Science.gov (United States)

    Barta, Michael L; Adam, Philip R; Dickenson, Nicholas E

    2017-01-01

    Type III secretion systems (T3SS) are highly conserved virulence factors employed by a large number of pathogenic gram-negative bacteria. Like many T3SS translocators, recombinant expression of the hydrophobic Shigella protein IpaB requires the presence of its cognate chaperone IpgC. Chaperone-bound IpaB is maintained in a nonfunctional state, which has hampered in vitro studies aimed at understanding molecular structure and function of this important class of T3SS proteins. Herein, we describe an expression and purification protocol that utilizes mild detergents to produce highly purified, homogeneous IpaB of defined oligomeric states.

  17. Risk factors for secondary transmission of Shigella infection within households: implications for current prevention policy

    Directory of Open Access Journals (Sweden)

    Boveé Lian

    2012-12-01

    Full Text Available Abstract Background Internationally, guidelines to prevent secondary transmission of Shigella infection vary widely. Cases, their contacts with diarrhoea, and those in certain occupational groups are frequently excluded from work, school, or daycare. In the Netherlands, all contacts attending pre-school (age 0–3 and junior classes in primary school (age 4–5, irrespective of symptoms, are also excluded pending microbiological clearance. We identified risk factors for secondary Shigella infection (SSI within households and evaluated infection control policy in this regard. Methods This retrospective cohort study of households where a laboratory confirmed Shigella case was reported in Amsterdam (2002–2009 included all households at high risk for SSI (i.e. any household member under 16 years. Cases were classified as primary, co-primary or SSIs. Using univariable and multivariable binomial regression with clustered robust standard errors to account for household clustering, we examined case and contact factors (Shigella serotype, ethnicity, age, sex, household size, symptoms associated with SSI in contacts within households. Results SSI occurred in 25/ 337 contacts (7.4%: 20% were asymptomatic, 68% were female, and median age was 14 years (IQR: 4–38. In a multivariable model adjusted for case and household factors, only diarrhoea in contacts was associated with SSI (IRR 8.0, 95% CI:2.7-23.8. In a second model, factors predictive of SSI in contacts were the age of case (0–3 years (IRRcase≥6 years:2.5, 95% CI:1.1-5.5 and 4–5 years (IRRcase≥6 years:2.2, 95% CI:1.1-4.3 and household size (>6 persons (IRR2-4 persons 3.4, 95% CI:1.2-9.5. Conclusions To identify symptomatic and asymptomatic SSI, faecal screening should be targeted at all household contacts of preschool cases (0–3 years and cases attending junior class in primary school (4–5 years and any household contact with diarrhoea. If screening was limited to these groups, only

  18. Short Report: High Incidence of Shigellosis Among Peruvian Soldiers Deployed in the Amazon River Basin

    National Research Council Canada - National Science Library

    Jones, Franca R; Sanchez, Jose L; Meza, Rina; Batsel, Tanis M; Burga, Rosa; Canal, Enrique; Block, Karla; Perez, Juan; Bautista, Christian T; Escobedo, Jorge

    2004-01-01

    ...). Most (83 of 90; 92%) of the Shigella isolates were S. flexneri, of which 57 (69%) were serotype 2a. Seventy-six percent of Shigella isolates were resistant to sulfamethoxazole/ trimethoprim and all were sensitive to ciprofloxacin. Peruvian soldiers may be an excellent population in which to test the efficacy of S. flexneri vaccines in advanced development.

  19. Development of a Live Attenuated Bivalent Oral Vaccine Against Shigella sonnei Shigellosis and Typhoid Fever.

    Science.gov (United States)

    Wu, Yun; Chakravarty, Sumana; Li, Minglin; Wai, Tint T; Hoffman, Stephen L; Sim, B Kim Lee

    2017-01-15

    Shigella sonnei and Salmonella Typhi cause significant morbidity and mortality. We exploited the safety record of the oral, attenuated S. Typhi vaccine (Ty21a) by using it as a vector to develop a bivalent oral vaccine to protect against S. sonnei shigellosis and typhoid fever. We recombineered the S. sonnei form I O-antigen gene cluster into the Ty21a chromosome to create Ty21a-Ss, which stably expresses S. sonnei form I O antigen. To enhance survivability in the acid environment of the stomach, we created an acid-resistant strain, Ty21a-AR-Ss, by inserting Shigella glutaminase-glutamate decarboxylase systems coexpressed with S. sonnei form I O-antigen gene. Mice immunized intranasally with Ty21a-AR-Ss produced antibodies against S. sonnei and S. Typhi, and survived lethal intranasal S. sonnei challenge. This paves the way for proposed good manufacturing practices manufacture and clinical trials intended to test the clinical effectiveness of Ty21a-AR-Ss in protecting against S. sonnei shigellosis and typhoid fever, as compared with the current Ty21a vaccine. © 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.

  20. Antagonistic activity expressed by Shigella sonnei: identification of a putative new bacteriocin

    Directory of Open Access Journals (Sweden)

    Mireille Angela Bernardes Sousa

    2013-09-01

    Full Text Available Bacteriocins are antibacterial, proteinaceous substances that mediate microbial dynamics. Bacteriocin production is a highly disseminated property among all major lineages of bacteria, including Shigella. In this paper, we addressed the purification and characterisation of a bacteriocin produced by a Shigella sonnei strain (SS9 isolated from a child with acute diarrhoea. The substance was purified through ammonium-sulphate precipitation and sequential steps of chromatography. The intracellular fraction obtained at 75% ammonium sulphate maintained activity following exposure to pH values from 1-11 and storage at -80ºC for more than two years and was inactivated by high temperatures and proteases. The molecular mass of the purified bacteriocin was determined by mass spectrometry to be 18.56 kDa. The N-terminal sequence of the bacteriocin did not match any other antibacterial proteins described. A putative new bacteriocin produced by S. sonnei has been detected. This bacteriocin may represent a newly described protein or a previously described protein with a newly detected function. Considering that SS9 expresses antagonism against other diarrhoeagenic bacteria, the bacteriocin may contribute to S. sonnei virulence and is potentially applicable to either preventing or controlling diarrhoeal disease.

  1. Single amino acid substitutions on the needle tip protein IpaD increased Shigella virulence.

    Science.gov (United States)

    Meghraoui, Alaeddine; Schiavolin, Lionel; Allaoui, Abdelmounaaïm

    2014-07-01

    Infection of colonic epithelial cells by Shigella is associated with the type III secretion system, which serves as a molecular syringe to inject effectors into host cells. This system includes an extracellular needle used as a conduit for secreted proteins. Two of these proteins, IpaB and IpaD, dock at the needle tip to control secretion and are also involved in the insertion of a translocation pore into host cell membrane allowing effector delivery. To better understand the function of IpaD, we substituted thirteen residues conserved among homologous proteins in other bacterial species. Generated variants were tested for their ability to surface expose IpaB and IpaD, to control secretion, to insert the translocation pore, and to invade host cells. In addition to a first group of seven ipaD variants that behaved similarly to the wild-type strain, we identified a second group with mutations V314D and I319D that deregulated secretion of all effectors, but remained fully invasive. Moreover, we identified a third group with mutations Y153A, T161D, Q165L and Y276A, that exhibited increased levels of translocators secretion, pore formation, and cell entry. Altogether, our results offer a better understanding of the role of IpaD in the control of Shigella virulence. Copyright © 2014 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

  2. Application of DNA hybridization techniques in the assessment of diarrheal disease among refugess in Thailand. [Shigella; Escherichia coli; Campylobacter; Cryptosporidium

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, D.N.; Echeverria, P.; Pitarangsi, C.; Seriwatana, J.; Sethabutr, O.; Bodhidatta, L.; Brown, C.; Herrmann, J.E.; Blacklow, N.R.

    1988-01-01

    The epidemiology and etiology of acute diarrheal disease were determined in a Hmong refugee camp on the Thai-Laotian border from April 11 to May 14, 1985. DNA hybridization techniques were used to detect Shigella species, enteroinvasive Escherichia coli, and enterotoxigenic E. coli. A monoclonal enzyme-linked immunosorbent assay was used to detect rotavirus, and standard microbiology was used to detect other enteropathogens. The age-specific diarrheal disease rates were 47 episodes per month per 1000 children less than five years old and 113 episodes per month per 1000 children less than one year old. Rotavirus, enterotoxigenic E. coli, Campylobacter, and Cryptosporidium were the predominant pathogens in children less than two years old. The DNA probe hybridized with 94% of 31 specimens identified as enterotoxigenic E. coli by the standard assays and with none of the specimens in which the standard assays were negative. The probe for Shigella and enteroinvasive E. coli hybridized in eight of 10 stools that contained Shigella and four of 314 stools from which Shigella and enteroinvasive E. coli were not isolated. The use of DNA probes allows specimens to be collected in remote areas with a minimum amount of equipment and technical expertise so that they can be easily transported to a central laboratory for further processing.

  3. The Comparison of Effect of Human Milk and Powdered Milk on the Shigella dysenteriae Invasion in Cell Culture

    Directory of Open Access Journals (Sweden)

    Mahdeye Azadi Aghdam

    2017-03-01

    Full Text Available Background: Shigella species are the common etiologic agents of bacterial dysentery. Many epidemiological studies have shown that breastfeeding may protect infants against intestinal infections. Among the components of milk, glycosylated proteins inhibit the adhesion of enteric pathogens in the laboratory. Immunoglobulins mainly secretory immunoglobulin A, glycosylated compounds, and oligosaccharides of breast milk are associated with protection against different intestinal pathogens. Objectives: This study aimed to evaluate the effect of different proteins of breast milk and powdered milk on the invasion of Shigella colonies. Materials and Methods: To accomplish this goal, breast milk samples were provided from two donors in the first 6 months of breastfeeding and powdered milk with different brands were obtained from the market. Then the proteins were extracted by precipitation using ammonium sulfate and dialysis using dialysis bag and protein bands were separated through SDS-PAGE electrophoresis. Finally, the obtained milk proteins through Hela cells culture were tested and evaluated for the adhesion and invasion of the Shigella. Results: Our results revealed that the adhesion and invasion of Shigella stains were more inhibited by low concentrations of breast milk proteins in comparison with powdered milk. This concentration was about 2.75 mg/mL for the proteins of breast milk and 0.5 mg/mL for the proteins of powdered milk and this inhibition in different dilutions of breast milk was 71.21% and those of powdered milk was 27.19% in average. There was a significant difference between breast milk and powdered milk (P < 0.5 considering their inhibitory behavior. Conclusion: The results revealed that the components of breast milk inhibit the adhesion and consequently invasion of Shigella and inhibit bacterial dysentery.

  4. Multicenter evaluation of molecular and culture-dependent diagnostics for Shigella species and Entero-invasive Escherichia coli in the Netherlands

    NARCIS (Netherlands)

    van den Beld, Maaike J. C.; Friedrich, Alexander W.; van Zanten, Evert; Reubsaet, Frans A. G.; Kooistra-Smid, Mirjam A. M. D.; Rossen, John W. A.

    2016-01-01

    An inter-laboratory collaborative trial for the evaluation of diagnostics for detection and identification of Shigella species and Entero-invasive Escherichia coil (EIEC) was performed. Sixteen Medical Microbiological Laboratories (MMLs) participated. MMLs were interviewed about their diagnostic

  5. Aloe vera (Aloe barbadensis Miller) supplemented probiotic lassi prevents Shigella infiltration from epithelial barrier into systemic blood flow in mice model.

    Science.gov (United States)

    Hussain, Shaik Abdul; Patil, Girdhari Ramdas; Reddi, Srinu; Yadav, Vidhu; Pothuraju, Ramesh; Singh, Ram Ran Bijoy; Kapila, Suman

    2017-01-01

    The aim of present work was to investigate preventive role of orally administered Aloe vera supplemented probiotic lassi (APL) on Shigella dysenteriae infection in mice. At the end of experimental period (2, 5 and 7 days of challenging), different organs such as spleen, liver, small intestine, large intestine, and peritoneal fluid were collected and assessed for Shigella colonization. Secretary IgA was estimated in intestinal fluid. Blood was collected in heparinized tubes for various haematological studies. Oral administration of APL showed a significant (p Shigella counts (log cfu/mL) in all organs as compared to other treatment groups at different intervals after post feeding. Similarly, secretary IgA antibody levels (μg/mL) in intestinal fluid were significantly (p Shigella dysenteriae induced infection in mice. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Removal of salmonella-typhi, shigella-dysenteriae, vibrio-cholerae and rotavirus from water using a water-treatment tablet

    CSIR Research Space (South Africa)

    Rodda, N

    1993-01-01

    Full Text Available previously demonstrated. This study evaluated the efficiency of removal of Salmonella typhi, Shigella dysenteriae, Vibrio cholerae and rotavirus from simulated hard water of high organic content and colour. All four pathogenic micro organisms were...

  7. Salmonelose humana e animal em Araraquara, S. Paulo: prevalência de Shigella em casos humanos

    Directory of Open Access Journals (Sweden)

    Deise Pasetto Falcão

    1975-10-01

    Full Text Available Admitida uma baixa freqüência de Salmonella com base em verificações anteriores em casos de diarréia aguda na cidade de Araraquara, S. Paulo, realizou-se uma investigação com um esquema ampliado para o isolamento de Salmonella a partir de 47 casos de gastroenterite infantil, 51 amostras de fezes de animais e 50 amostras de carnes e vísceras de animais destinados a alimentação. Foram isoladas Salmonella em 6,3% dos casos de gastroenterite, 5,8% de fezes de animais e 8,0% de amostras de alimentos, nesse último caso verificando-se a contaminação exclusivamente em fígado de porco, senão negativos todos os resultados de carne e vísceras de bovinos. Os sorotipos isolados corresponderam, em ordem decrescente de freqüência a S. anatum, S. derby e S. daytona. Nas gastroenterites infantis a freqüência de Shigella (12,7% foi duas vezes superior à de Salmonella (6,3%.After some observations, which indicated a low prevalence of Salmonella infections in the area of Araraquara, S. Paulo, an extended schedule of enrichment and isolation media were applied for investigating the presence of Salmonella organisms in 47 fecal specimens from infantile gastroenterites, 51 stool specimens from animais and 50 food samples of animal origin. Salmonella isolates were obtained in 6,3% of the g astro enter itis cases; 5,8% from animal stool cultures and 8,0% from food stuffs. In the last case only pork liver gave positive results, with no isolations being achieved from beef Products. S. anatum, S. derby and S. daytona were found in descendiny order of frequency. As related to the gastroenteritis cases Shigella organisms were twice as frequent than the Salmonella.

  8. [Role of CRISPR/Cas systems in drugresistance and virulence and the effect of IS600 on the expression of cse2 in Shigella].

    Science.gov (United States)

    Hong, Lijuan; Zhang, Bing; Duan, Guangcai; Liang, Wenjuan; Wang, Yingfang; Chen, Shuaiyin; Yang, Haiyan; Xi, Yuanlin

    2016-12-04

    To analyze the relationship between CRISPR/Cas system and drug-resistance, virulence. To investigate the effect of IS600 on the expression of CRISPR associated gene cse2 in Shigella. CRISPR loci, CRISPR associated gene cse2, drug-resistant genes and virulent genes were detected by PCR in 33 Shigella strains; Trypan Blue counting test was used to detect bacterial virulence; Real-time PCR was used to detect relative mRNA expression of cse2; susceptibilities of Shigella strains were tested by agar diffusion method. Furthermore, we analyzed the relationship between CRISPR loci and drug-resistant genes, virulent genes. The effect of the IS600 on the expression of CRISPR associated gene cse2 was investigated. The mortality of Hela cells infected by Shigella with CRISPR1 loci was significantly lower (PShigella without CRISPR1. The mRNA expression level of cse2 in group with IS600 was significantly (PShigella. Shigella without CRISPR1 has a higher pathogenicity. Due to the insertion of IS600, the mRNA expression level of cse2 was decreased in Shigella.

  9. Molecular characterization of the extended-spectrum beta-lactamase (ESBL)-producing Shigella spp. in Shanghai.

    Science.gov (United States)

    Li, J; Li, B; Ni, Y; Sun, J

    2015-03-01

    Shigellosis is a public health concern in China. We tested 216 Shigella isolates collected in Shanghai in 2007 for the production of extended-spectrum beta-lactamases (ESBLs). ESBL-producing isolates were characterized using polymerase chain reaction (PCR)-based genotyping, conjugation, pulsed-field gel electrophoresis (PFGE), and DNA sequence analysis of regions adjacent to bla genes. Plasmids containing genes encoding ESBLs were analyzed using plasmid replicon typing. ESBLs were produced by 18.1 % (39/216) of Shigella isolates, and all 39 ESBL-producing strains harbored bla CTX-M genes. CTX-M-14 was the most frequent variant (69.2 %, 27/39), followed by CTX-M-15 (15.4 %, 6/39). All bla CTX-M genes were transferable by conjugation, and the insertion sequence ISEcp1 was detected upstream of all bla CTX-M genes. The CTX-M-producing Shigella isolates showed high clonal diversity. IncI1, IncFII, IncN, and IncB/O replicons were respectively detected in 23 (58.9 %), 9 (23.1 %), 1 (2.6 %), and 1 (2.6 %) of the 39 transconjugants carrying bla CTX-M. The bla CTX-M-14 genes were most frequently carried by IncI1 (n = 13, 48.1 %) or IncFII (n = 9, 33.3 %) plasmids, and the bla CTX-M-15 genes were closely associated with IncI1 (n = 5, 83.3 %). Our findings demonstrate the high prevalence of ESBL-producing Shigella in Shanghai, the importance of plasmids and ISEcp1 as carriers of bla CTX-M genes, and the close association between certain bla CTX-M genes with a specific plasmid.

  10. Serological cross-reaction between O-antigens of Shigella dysenteriae type 4 and an environmental Escherichia albertii isolate.

    Science.gov (United States)

    Rahman, Mohammed Ziaur; Akter, Selina; Azmuda, Nafisa; Sultana, Munawar; Weill, François-Xavier; Khan, Sirajul Islam; Grimont, Patrick A D; Birkeland, Nils-Kåre

    2013-11-01

    An environmental freshwater bacterial isolate, DM104, appearing as Shigella-like colonies on selective agar plates was found to show strong and specific serological cross-reactivity with Shigella dysenteriae type 4. Biochemical identification according to the analytical profile index, molecular serotyping by restriction of the amplified O-antigen gene cluster (rfb-RFLP), together with phylogenetic analysis of the 16S rRNA gene and multi-locus sequence analysis, identified the isolate as Escherichia albertii. rfb-RFLP of DM104, revealed a profile different from that of S. dysenteriae type 4. However, western blot analysis of extracted lipopolysaccharides demonstrated strong cross-reactivity with S. dysenteriae type 4 using specific monovalent antisera and a lipopolysaccharide gel banding profile similar to that of S. dysenteriae type 4. The observed O-antigen cross-reaction between an E. albertii isolate and S. dysenteriae extends our knowledge of the extent of O-antigen cross-reaction within the Escherichia/Shigella group of organisms, and offers the possibility of using DM104 and similar cross-reacting strains as shigellosis vaccine candidates.

  11. Multi drug resistance and Extended Spectrum Beta Lactamases in clinical isolates of Shigella: A study from New Delhi, India.

    Science.gov (United States)

    Aggarwal, Prabhav; Uppal, Beena; Ghosh, Roumi; Krishna Prakash, S; Chakravarti, Anita; Jha, Arun Kumar; Rajeshwari, Krishnan

    2016-01-01

    Shigella is an important cause of gastroenteritis in local Indian population, as well as of traveler's diarrhea in the international visitors to India. These patients often require appropriate antimicrobial therapy; however, rapid development of antimicrobial resistance poses a major hurdle in achieving this goal. A prospective study was conducted during 2009-12 in New Delhi, India, including 6339 stool samples from gastroenteritis patients. 121 Shigella strains were identified on the basis of colony morphology, biochemical reactions, serotyping and ipaH gene based PCR. Antimicrobial susceptibility testing by disc diffusion, MIC determination by Vitek(®) 2 and phenotypic tests for ESBL/AmpC production were done. Nineteen percent strains (23/121) were found to be resistant to third generation cephalosporins and all were phenotypically confirmed to be ESBL producers; one strain was positive for AmpC. ESBL producing strains were also found to be significantly more resistant (p Shigella is a matter of concern for the local population as well as international travelers. Therefore, better national level antimicrobial management programs are the priority needs. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. VirF-Independent Regulation of Shigella virB Transcription is Mediated by the Small RNA RyhB

    Science.gov (United States)

    Broach, William H.; Egan, Nicholas; Wing, Helen J.; Payne, Shelley M.; Murphy, Erin R.

    2012-01-01

    Infection of the human host by Shigella species requires the coordinated production of specific Shigella virulence factors, a process mediated largely by the VirF/VirB regulatory cascade. VirF promotes the transcription of virB, a gene encoding the transcriptional activator of several virulence-associated genes. This study reveals that transcription of virB is also regulated by the small RNA RyhB, and importantly, that this regulation is not achieved indirectly via modulation of VirF activity. These data are the first to demonstrate that the regulation of virB transcription can be uncoupled from the master regulator VirF. It is also established that efficient RyhB-dependent regulation of transcription is facilitated by specific nucleic acid sequences within virB. This study not only reveals RyhB-dependent regulation of virB transcription as a novel point of control in the central regulatory circuit modulating Shigella virulence, but also highlights the versatility of RyhB in controlling bacterial gene expression. PMID:22701677

  13. The detection and antimicrobial susceptibility profile of Shigella isolates from meat and swab samples at butchers' shops in Gondar town, Northwest Ethiopia.

    Science.gov (United States)

    Garedew, Legesse; Hagos, Zenabu; Zegeye, Bidir; Addis, Zelalem

    2016-01-01

    Food borne pathogens are major causes of deaths, illnesses and billions of dollars of expenses. The burden of food borne illness is worsened by the ever increasing rate of antimicrobial resistance microbes. Shigella, a bacterial pathogen associated with food, is reported to account for higher prevalence rates of food borne illness in different settings. A cross-sectional study was conducted from February 10 to June 30, 2013, at the butcher houses of Gondar town in the Northwest of Ethiopia to assess the prevalence and antimicrobial susceptibility pattern of Shigella. Cattle raw meat and swab samples from selected critical control points, including knives, chopping boards, and the hands and noses of butchers, were collected and analyzed. The identification of Shigella was carried out using colony characteristics, the Gram reaction, and biochemical tests. Antimicrobial susceptibility testing was performed using the Kirby-Bauer disc diffusion method. The overall hygienic status of the butcher shops was also assessed using a checklist. An observational analysis revealed that the sanitary condition of the butcher shops and their premises was poor. Of 306 samples screened, 10.5% were positive for Shigella. Approximately 7.4% of meat samples and 10.2% of swab samples were contaminated with Shigella. Out of the total Shigella isolates, 90.6%, 46.9%, 18.8% and 9.4% were resistant to ampicillin, amoxicillin, ceftriaxone and tetracycline, respectively. A multidrug resistance pattern was recorded in 27.8% of the isolates. In conclusion, the safety of meat sold at Gondar butchers houses was poor. The identified Shigella isolates showed high levels of drug resistance and multidrug resistance patterns for commonly used antimicrobials in veterinary and human medicine. Practicing wise use of antimicrobials and strict sanitary interventions at different critical control points is strongly recommended, in addition to further in-depth studies to prevent unprecedented consequences from

  14. Prevalence of intestinal parasite, Shigella and Salmonella species among diarrheal children in Jimma health center, Jimma southwest Ethiopia: a cross sectional study.

    Science.gov (United States)

    Beyene, Getenet; Tasew, Haimanot

    2014-02-05

    Diarrheal disease continues to be an important cause of morbidity and mortality among young children in developing countries including Ethiopia. Globally, intestinal parasite, Shigella and Salmonella species remain major contributors to acute enteric infections. The study was aimed at determining the frequency of intestinal parasite, Shigella and Salmonella species identified from diarrheic children at Jimma Health Centre, Jimma south west Ethiopia. A health institution based cross sectional study was conducted from March to November 2012. A structured questionnaire was used for collection of data on socio- demographic characteristics. Parasite and bacteria identification as well as susceptibility testing was done using standard parasitological and bacteriological procedures. A total of 260 diarrheal children were included in the study. A total of 129 (49.6%) samples were positive for intestinal parasite, Shigella and Salmonella species. Of these, 107 (41.1%), 6 (2.3%) and 16 (6.2%) samples were positive for intestinal parasite, Shigella and Salmonella species respectively. The dominant isolated parasite was G. lamblia with prevalence of 13.5% followed by A. lumbricoides (11.5%). The least identified parasites were Schistosoma mansoni and Taenia species accounting 0.4% each. Multiple parasitic infections were observed in 19 (7.3%) patients. Shigella species showed hundred percent resistances to ampicillin, amoxacillin, and cotrimoxazole. All Salmonella isolates were resistant against amoxicillin. All Shigella and Salmonella species were susceptible to ceftriaxone, ciprofloxacin and gentamycin. The presence of reasonably high amount of intestinal parasite and Salmonella and Shigella species that are drug resistance to the commonly prescribed drugs is a treat to the children and community at large. Therefore, measures including health education, improvement of safe water supply, sanitation facilities and continuous monitoring of microbiological and antimicrobial

  15. PENGETAHUAN DAN PERSEPSI IBU BALITA MENGENAI PENYAKIT SHIGELLA SERTA VAKSINASI PENCEGAHANNYA (KAJIAN KUALITATIF

    Directory of Open Access Journals (Sweden)

    Rachmalina S. P.

    2012-11-01

    Full Text Available Shigellosis is a part of diarrhoeal diseases and its still prevalent in several areas of Indonesia including Jakarta. A qualitative study was carried out to determine the knowledge and perceptions of Toddler's mother about shigellosis and its prevention since the majority of sufferer was toddler's who were unable to speak about their disease. According to the toddler's mothers, shigellosis was known as "muntah berak" since its symptoms were frequent defecation (more than 4 times with liquid faeces along with blood. The causes of the disease include unprotected food and water that were contaminated by flies, intolerance to certain type of molk or certain food. In relation to their behavior, the cause of disease was eating with dirty hand. Some traditional healings were believed to cure the disease instead of going to Health Center. Most of respondents knew about the function of vaccination was to prevent the disease, however, the term "immunization" was more popular than '"vaccination" Keyword: knowledge, perseption, toddler's mother, shigella, vaccination

  16. Antimicrobial activity against Shigella sonnei and probiotic properties of wild lactobacilli from fermented food.

    Science.gov (United States)

    Zhang, Yingchun; Zhang, Lanwei; Du, Ming; Yi, Huaxi; Guo, Chunfeng; Tuo, Yanfeng; Han, Xue; Li, Jingyan; Zhang, Lili; Yang, Lin

    2011-12-20

    Four lactobacilli strains (Lactobacillus paracasei subp. paracasei M5-L, Lactobacillus rhamnosus J10-L, Lactobacillus casei Q8-L and L. rhamnosus GG (LGG), were systematically assessed for the production of antimicrobial substances active towards Shigella sonnei, Escherichia coli and Salmonella typhimurium. Agar-well assay showed that the four lactobacilli strains displayed strong antibacterial activity towards S. sonnei. The nature of antimicrobial substances was also investigated and shown to be dependent on the production of organic acids, in particular the lactic acid. Time-kill assay showed that the viability of the S. sonnei was decreased by 2.7-3.6logCFU/ml after contact with CFCS (cell-free culture supernatants) of four lactobacilli for 2h, which confirmed the result of the agar-well assay. Further analysis of the organic acid composition in the CFCS revealed that the content of lactic acid range from 227 to 293mM. In addition, the aggregations properties, adherence properties and tolerance to simulated gastrointestinal conditions were also investigated in vitro tests. The result suggested that the M5-L, J10-L and Q8-L strains possess desirable antimicrobial activity towards S. sonnei and probiotic properties as LGG and could be potentially used as novel probiotic strains in the food industry. Copyright © 2011. Published by Elsevier GmbH.

  17. Shigella dysenteriae infection activates proinflammatory response through β-catenin/NF-κB signaling pathway.

    Directory of Open Access Journals (Sweden)

    Ashidha Gopal

    Full Text Available Shigella dysenteriae (S.dysenteriae the causative agent of bacillary dysentery invades the human colonic epithelium resulting in severe intestinal inflammatory response and epithelial destruction. However, the mechanism by which S.dysenteriae infection regulates proinflammatory cytokines during intestinal inflammation is still obscure. In this study, we evaluated whether the interaction of β-catenin and NF-κB regulates proinflammatory cytokines TNF-α and IL-8 by modulating GSK-3β activity during S.dysenteriae infection in rat ileal loop model. Here we demonstrated that S.dysenteriae infection stimulate β-catenin degradation which in turn decreased the association between NF-κB and β-catenin. Also, we showed that S.dysenteriae infection increased GSK-3β kinase activity which in turn phosphorylates β-catenin for its degradation by ubiquitination and upregulates IL-8 through NF-κB activation thereby leading to inflammation. Thus these findings revealed the role of β-catenin/ NF-κB and GSK-3β in modulating the inflammatory response during bacterial infection and also showed that β-catenin acts as a critical regulator of inflammation.

  18. Development of multiple cross displacement amplification label-based gold nanoparticles lateral flow biosensor for detection of Shigella spp.

    Directory of Open Access Journals (Sweden)

    Yi Wang

    2016-11-01

    Full Text Available Shigella spp., the etiological agent of shigellosis or bacillary dysentery, are responsible for considerable morbidity and mortality in excess of a million deaths globally per year. Although PCR-based techniques (such as PCR-based dipstick biosensors have been used for the molecular diagnosis of infectious disease, these assays were restricted due to the need for a sophisticated thermal cycling apparatus to denature target templates. To facilitate simple and rapid detection of target pathogens, we successfully devised an inexpensive, reliable and nearly instrument-free molecular technique, which incorporates multiple cross displacement amplification (MCDA combined with a newly designed lateral flow biosensor (LFB for visual, sensitive and specific detection of Shigella. The MCDA-LFB assay was conducted at 65 ˚C for only 20 min during the amplification stage, and then products were directly analyzed on the biosensor, alleviating the use of special reagents, electrophoresis equipment and amplicon detection instruments. The entire process, including specimen processing (35 min, amplification (20 and detection (2-5 min, can be finished within 1 h. The MCDA-LFB assay demonstrated high specificity for Shigella detection. The analytical sensitivity of the assay was 10 fg of genomic templates per reaction in pure culture and 5.86 CFU per tube in human fecal samples, which was consistent with MCDA by colorimetric indicator, gel electrophoresis, real time turbidity and fluorescence detection. Hence, the simplicity, rapidity and nearly instrument-free platform of the MCDA-LFB assay make it practical for ‘on-site’ diagnosis, point-of-care testing and more. Moreover, the proof-of-concept approach can be reconfigured to detect a wide variety of target sequences by re-designing the specific MCDA primers.

  19. Vaccines for viral and bacterial pathogens causing acute gastroenteritis: Part II: Vaccines for Shigella, Salmonella, enterotoxigenic E. coli (ETEC) enterohemorragic E. coli (EHEC) and Campylobacter jejuni

    Science.gov (United States)

    O’Ryan, Miguel; Vidal, Roberto; del Canto, Felipe; Carlos Salazar, Juan; Montero, David

    2015-01-01

    In Part II we discuss the following bacterial pathogens: Shigella, Salmonella (non-typhoidal), diarrheogenic E. coli (enterotoxigenic and enterohemorragic) and Campylobacter jejuni. In contrast to the enteric viruses and Vibrio cholerae discussed in Part I of this series, for the bacterial pathogens described here there is only one licensed vaccine, developed primarily for Vibrio cholerae and which provides moderate protection against enterotoxigenic E. coli (ETEC) (Dukoral®), as well as a few additional candidates in advanced stages of development for ETEC and one candidate for Shigella spp. Numerous vaccine candidates in earlier stages of development are discussed. PMID:25715096

  20. Genetic relatedness of ciprofloxacin-resistant Shigella dysenteriae type 1 strains isolated in south Asia.

    Science.gov (United States)

    Talukder, Kaisar A; Khajanchi, Bijay K; Islam, M Aminul; Dutta, Dilip K; Islam, Zhahirul; Safa, Ashrafus; Khan, G Y; Alam, Khorshed; Hossain, M A; Malla, Sarala; Niyogi, S K; Rahman, Mustafizur; Watanabe, Haruo; Nair, G Balakrish; Sack, David A

    2004-10-01

    The aim of the present study was to determine the clonal relationships of ciprofloxacin-resistant Shigella dysenteriae type 1 strains isolated from south Asia, and S. dysenteriae 1 strains associated with epidemics in 1978, 1984 and 1994. The antimicrobial susceptibilities were examined by NCCLS methods. Molecular epidemiological characterization was performed by plasmid profiling, pulsed-field gel electrophoresis (PFGE) and mutation analysis of the quinolone resistance-determining region (QRDR) of gyrA by sequencing. Plasmid patterns of the current ciprofloxacin-resistant strains from India, Nepal and Bangladesh were very similar to those of the 1978, 1984 and 1994 epidemic isolates of S. dysenteriae 1, except for the presence of a new plasmid of approximately 2.6 MDa, which was found in one recent ciprofloxacin-resistant strain isolated in Bangladesh. PFGE analysis showed that the ciprofloxacin-resistant strains isolated in Bangladesh, India and Nepal belonged to a PFGE type (type A), which was possibly related to that of the 1984 and 1994 clone of S. dysenteriae 1, but different from 1978 epidemic strains. The current ciprofloxacin-resistant strains belong to five subtypes (A3-A7), all of which were found in India, but in Bangladesh and Nepal, only A3 existed. Mutation analysis of the QRDR of gyrA revealed that amino acid substitutions at positions 83 and 87 of ciprofloxacin-resistant strains isolated in Bangladesh were similar to those of the strains isolated in Nepal, but different (at position 87) from ciprofloxacin-resistant strains isolated in India. PFGE and mutation analysis of gyrA showed differences between the current ciprofloxacin-resistant S. dysenteriae 1 strains isolated in south Asia and those associated with epidemics in 1978, 1984 and 1994.

  1. Competitive Survival of Escherichia coli, Vibrio cholerae, Salmonella typhimurium and Shigella dysenteriae in Riverbed Sediments.

    Science.gov (United States)

    Abia, Akebe Luther King; Ubomba-Jaswa, Eunice; Momba, Maggy Ndombo Benteke

    2016-11-01

    Studies on the survival of bacterial enteric pathogens in riverbed sediments have mostly focused on individual organisms. Reports on the competitive survival of these pathogens in riverbed sediments under the same experimental setup are limited. We investigated the survival of Escherichia coli, Salmonella enterica ser. Typhimurium, Vibrio cholerae and Shigella dysenteriae in riverbed sediments of the Apies River. Experiments were performed in flow chambers containing three sediment types and connected to aquarium pumps immersed in river water to maintain continuous water circulation. Each chamber was inoculated with ~10 7  CFU/mL (final concentration) of each microorganism and kept at 4, 20 and 30 °C. Chambers were sampled on days 0, 1, 2, 7, 14 and 28. At 4 °C, only E. coli and S. typhimurium survived throughout the 28 experimental days. V. cholerae had the shortest survival time at this temperature and was not detected in any of the sediment chambers 24 h after inoculation. S. dysenteriae only survived until day 7. At an increased temperature of 20 °C, only S. dysenteriae was not detected on day 28 of the experiment. At 30 °C, V. cholerae and Salmonella survived longer (28 days) than E. coli (14 days) and S. dysenteriae (4 days). Vibrio cholerae was shown to have the highest T 90 values (32 days) in all sediment types at 20 and 30 °C. We conclude that the sediments of the Apies River present a favourable environment for the survival of indicator and pathogenic bacteria depending on the prevailing temperature.

  2. Identification of immune correlates of protection in Shigella infection by application of machine learning.

    Science.gov (United States)

    Arevalillo, Jorge M; Sztein, Marcelo B; Kotloff, Karen L; Levine, Myron M; Simon, Jakub K

    2017-10-01

    Immunologic correlates of protection are important in vaccine development because they give insight into mechanisms of protection, assist in the identification of promising vaccine candidates, and serve as endpoints in bridging clinical vaccine studies. Our goal is the development of a methodology to identify immunologic correlates of protection using the Shigella challenge as a model. The proposed methodology utilizes the Random Forests (RF) machine learning algorithm as well as Classification and Regression Trees (CART) to detect immune markers that predict protection, identify interactions between variables, and define optimal cutoffs. Logistic regression modeling is applied to estimate the probability of protection and the confidence interval (CI) for such a probability is computed by bootstrapping the logistic regression models. The results demonstrate that the combination of Classification and Regression Trees and Random Forests complements the standard logistic regression and uncovers subtle immune interactions. Specific levels of immunoglobulin IgG antibody in blood on the day of challenge predicted protection in 75% (95% CI 67-86). Of those subjects that did not have blood IgG at or above a defined threshold, 100% were protected if they had IgA antibody secreting cells above a defined threshold. Comparison with the results obtained by applying only logistic regression modeling with standard Akaike Information Criterion for model selection shows the usefulness of the proposed method. Given the complexity of the immune system, the use of machine learning methods may enhance traditional statistical approaches. When applied together, they offer a novel way to quantify important immune correlates of protection that may help the development of vaccines. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Characterization of Small Molecule Scaffolds that Bind to the Shigella Type III Secretion System Protein IpaD

    Science.gov (United States)

    Dey, Supratim; Anbanandam, Asokan; Mumford, Ben E.; De Guzman, Roberto N.

    2017-01-01

    Many pathogens such as Shigella and other bacteria assemble the type III secretion system (T3SS) nanoinjector to inject virulence proteins into their target cells to cause infectious diseases in humans. The rise of drug resistance among pathogens that rely on the T3SS for infectivity, plus the dearth of new antibiotics require alternative strategies in developing new antibiotics. The Shigella T3SS tip protein IpaD is an attractive target for developing anti-infectives because of its essential role in virulence and its exposure on the bacterial surface. Currently, the only known small molecules that bind to IpaD are bile salts sterols. Here, we identified four new small molecule scaffolds that bind to IpaD based on the methylquinoline, pyrrolidin-aniline, hydroxyindole, and morpholinoaniline scaffolds. NMR mapping revealed potential hotspots in IpaD for binding small molecules. These scaffolds can be used as building blocks in developing small molecule inhibitors of IpaD that could lead to new anti-infectives. PMID:28750143

  4. Characterization of Small-Molecule Scaffolds That Bind to the Shigella Type III Secretion System Protein IpaD.

    Science.gov (United States)

    Dey, Supratim; Anbanandam, Asokan; Mumford, Ben E; De Guzman, Roberto N

    2017-09-21

    Many pathogens such as Shigella and other bacteria assemble the type III secretion system (T3SS) nanoinjector to inject virulence proteins into their target cells to cause infectious diseases in humans. The rise of drug resistance among pathogens that rely on the T3SS for infectivity, plus the dearth of new antibiotics require alternative strategies in developing new antibiotics. The Shigella T3SS tip protein IpaD is an attractive target for developing anti-infectives because of its essential role in virulence and its exposure on the bacterial surface. Currently, the only known small molecules that bind to IpaD are bile salt sterols. In this study we identified four new small-molecule scaffolds that bind to IpaD, based on the methylquinoline, pyrrolidine-aniline, hydroxyindole, and morpholinoaniline scaffolds. NMR mapping revealed potential hotspots in IpaD for binding small molecules. These scaffolds can be used as building blocks in developing small-molecule inhibitors of IpaD that could lead to new anti-infectives. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Characterization and complete genome sequence of a novel N4-like bacteriophage, pSb-1 infecting Shigella boydii.

    Science.gov (United States)

    Jun, Jin Woo; Yun, Sae Kil; Kim, Hyoun Joong; Chai, Ji Young; Park, Se Chang

    2014-10-01

    Shigellosis is one of major foodborne pathogens in both developed and developing countries. Although antibiotic therapy is considered an effective treatment for shigellosis, the imprudent use of antibiotics has led to the increase of multiple-antibiotic-resistant Shigella species globally. In this study, we isolated a virulent Podoviridae bacteriophage (phage), pSb-1, that infects Shigella boydii. One-step growth analysis revealed that this phage has a short latent period (15 min) and a large burst size (152.63 PFU/cell), indicating that pSb-1 has good host infectivity and effective lytic activity. The double-stranded DNA genome of pSb-1 is composed of 71,629 bp with a G + C content of 42.74%. The genome encodes 103 putative ORFs, 9 putative promoters, 21 transcriptional terminators, and one tRNA region. Genome sequence analysis of pSb-1 and comparative analysis with the homologous phage EC1-UPM, N4-like phage revealed that there is a high degree of similarity (94%, nucleotide sequence identity) between pSb-1 and EC1-UPM in 73 of the 103 ORFs of pSb-1. The results of this investigation indicate that pSb-1 is a novel virulent N4-like phage infecting S. boydii and that this phage might have potential uses against shigellosis. Copyright © 2014 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

  6. In vitro adherence patterns of Shigella serogroups to bovine recto-anal junction squamous epithelial (RSE) cells are similar to those of Escherichia coli O157

    Science.gov (United States)

    The aim of this study was to determine whether Shigella species, which are human gastrointestinal pathogens, can adhere to cattle recto-anal junction squamous epithelial (RSE) cells using a recently standardized adherence assay, and to compare their adherence patterns to that of Escherichia coli O15...

  7. Simultaneous and individual quantitative estimation of Salmonella, Shigella and Listeria monocytogenes on inoculated Roma tomatoes (Lycopersicon esculentum var. Pyriforme) and Serrano peppers (Capsicum annuum) using an MPN technique.

    Science.gov (United States)

    Cabrera-Díaz, E; Martínez-Chávez, L; Sánchez-Camarena, J; Muñiz-Flores, J A; Castillo, A; Gutiérrez-González, P; Arvizu-Medrano, S M; González-Aguilar, D G; Martínez-Gonzáles, N E

    2018-08-01

    Simultaneous and individual enumeration of Salmonella, Shigella and Listeria monocytogenes was compared on inoculated Roma tomatoes and Serrano peppers using an Most Probable Number (MPN) technique. Samples consisting of tomatoes (4 units) or peppers (8 units) were individually inoculated with a cocktail of three strains of Salmonella, Shigella or L. monocytogenes, or by simultaneous inoculation of three strains of each pathogen, at low (1.2-1.7 log CFU/sample) and high (2.2-2.7 log CFU/sample) inocula. Samples were analyzed by an MPN technique using universal pre-enrichment (UP) broth at 35 °C for 24 ± 2 h. The UP tubes from each MPN series were transferred to enrichment and plating media following adequate conventional methods for isolating each pathogen. Data were analyzed using multifactorial analysis of variance (p  simultaneous), type of bacteria (Salmonella > Shigella and L. monocytogenes), type of sample (UP broth > pepper and tomato), and inoculum level (high > low). The MPN technique was effective for Salmonella on both commodities. Shigella counts were higher on tomatoes compared to peppers, (p < 0.05), and for L. monocytogenes on peppers (p < 0.05). Copyright © 2018 Elsevier Ltd. All rights reserved.

  8. Molecular and functional profiling of the polyamine content in enteroinvasive E. coli : looking into the gap between commensal E. coli and harmful Shigella.

    Directory of Open Access Journals (Sweden)

    Rosaria Campilongo

    Full Text Available Polyamines are small molecules associated with a wide variety of physiological functions. Bacterial pathogens have developed subtle strategies to exploit polyamines or manipulate polyamine-related processes to optimize fitness within the host. During the transition from its innocuous E. coli ancestor, Shigella, the aetiological agent of bacillary dysentery, has undergone drastic genomic rearrangements affecting the polyamine profile. A pathoadaptation process involving the speG gene and the cad operon has led to spermidine accumulation and loss of cadaverine. While a higher spermidine content promotes the survival of Shigella within infected macrophages, the lack of cadaverine boosts the pathogenic potential of the bacterium in host tissues. Enteroinvasive E. coli (EIEC display the same pathogenicity process as Shigella, but have a higher infectious dose and a higher metabolic activity. Pathoadaption events affecting the cad locus have occurred also in EIEC, silencing cadaverine production. Since EIEC are commonly regarded as evolutionary intermediates between E. coli and Shigella, we investigated on their polyamine profile in order to better understand which changes have occurred along the path to pathogenicity. By functional and molecular analyses carried out in EIEC strains belonging to different serotypes, we show that speG has been silenced in one strain only, favouring resistance to oxidative stress conditions and survival within macrophages. At the same time, we observe that the content of spermidine and putrescine, a relevant intermediate in the synthesis of spermidine, is higher in all strains as compared to E. coli. This may represent an evolutionary response to the lack of cadaverine. Indeed, restoring cadaverine synthesis decreases the expression of the speC gene, whose product affects putrescine production. In the light of these results, we discuss the possible impact of pathoadaptation events on the evolutionary emergence of a

  9. New strategies for genetic engineering Pseudomonas syringae using recombination

    Science.gov (United States)

    Here we report that DNA oligonucleotides (oligos) introduced directly into bacteria by electroporation can recombine with the bacterial chromosome. This phenomenon was identified in Pseudomonas syringae and we subsequently found that Escherichia coli, Salmonella typhimurium and Shigella flexneri are...

  10. Leylabadlo et al., Afr., J. Infect. Dis. (2017) 11 (2): 39-53 https://doi ...

    African Journals Online (AJOL)

    hamed

    In another study from pediatric patients for ESBL genes, about 30.5% ..... previous studies from Taiwan and Mexico, it has been reported that blaSHV and ...... and enhanced expression of genes for efflux pumps in Shigella flexneri and.

  11. Development of selective and differential medium for Shigella sonnei using three carbohydrates (lactose, sorbitol, and xylose) and X-Gal.

    Science.gov (United States)

    Na, G N; Kim, S A; Kwon, O C; Rhee, M S

    2015-08-01

    The aim of this study was to develop a new selective and differential medium for isolating Shigella sonnei (designated 3SD medium). The new medium was based on three carbohydrates (lactose, sorbitol, and xylose) and a chromogenic substrate (5-bromo-4-chloro-3-indolyl-β-D-galactopyranoside, X-Gal). S. sonnei cannot ferment lactose, sorbitol, or xylose, but can ferment X-Gal, which generates turquoise-blue colonies with rough edges. Other bacteria (54 strains of foodborne pathogens and spoilage bacteria) produced visually distinct colonies on 3SD medium (colorless or pink-violet colonies), or their growth was inhibited on 3SD medium. The optimum concentration of 50 mg/L X-Gal was selected because it yielded the highest level of morphological discrimination between S. sonnei and other bacteria, and this concentration was cost-effective. Bile salt concentration optimization was performed using healthy, heat-injured, and acid-injured S. sonnei. The recovery rate differed significantly depending on the bile salt concentration; media containing >1.0 g/L bile salt showed significantly lower recovery of stress-injured cells than medium containing 0.5 g/L bile salt (P<0.05). Growth of all Gram-positive bacteria was inhibited on medium containing 0.5 g/L bile salt; therefore, this concentration was used as the optimal concentration. Previous media used to isolate Shigella spp. (MacConkey, xylose lysine desoxycholate, and Salmonella-Shigella agar) showed poor performance when used to support the growth of injured S. sonnei cells, whereas 3SD medium supported a high growth rate of injured and healthy cells (equivalent to that obtained with nutrient-rich tryptic soy agar). To validate the performance of 3SD medium with real specimens, S. sonnei and other bacteria were spiked into samples such as untreated water, carrot, salad, and oyster. 3SD medium showed superior specificity (100%) and sensitivity (100%) for S. sonnei, and yielded no false-positive or false-negative results

  12. Phenylbutyrate counteracts Shigella mediated downregulation of cathelicidin in rabbit lung and intestinal epithelia: a potential therapeutic strategy.

    Directory of Open Access Journals (Sweden)

    Protim Sarker

    Full Text Available BACKGROUND: Cathelicidins and defensins are endogenous antimicrobial peptides (AMPs that are downregulated in the mucosal epithelia of the large intestine in shigellosis. Oral treatment of Shigella infected rabbits with sodium butyrate (NaB reduces clinical severity and counteracts the downregulation of cathelicidin (CAP-18 in the large intestinal epithelia. AIMS: To develop novel regimen for treating infectious diseases by inducing innate immunity, we selected sodium 4-phenylbutyrate (PB, a registered drug for a metabolic disorder as a potential therapeutic candidate in a rabbit model of shigellosis. Since acute respiratory infections often cause secondary complications during shigellosis, the systemic effect of PB and NaB on CAP-18 expression in respiratory epithelia was also evaluated. METHODS: The readouts were clinical outcomes, CAP-18 expression in mucosa of colon, rectum, lung and trachea (immunohistochemistry and real-time PCR and release of the CAP-18 peptide/protein in stool (Western blot. PRINCIPAL FINDINGS: Significant downregulation of CAP-18 expression in the epithelia of rectum and colon, the site of Shigella infection was confirmed. Interestingly, reduced expression of CAP-18 was also noticed in the epithelia of lung and trachea, indicating a systemic effect of the infection. This suggests a causative link to acute respiratory infections during shigellosis. Oral treatment with PB resulted in reduced clinical illness and upregulation of CAP-18 in the epithelium of rectum. Both PB and NaB counteracted the downregulation of CAP-18 in lung epithelium. The drug effect is suggested to be systemic as intravenous administration of NaB could also upregulate CAP-18 in the epithelia of lung, rectum and colon. CONCLUSION: Our results suggest that PB has treatment potential in human shigellosis. Enhancement of CAP-18 in the mucosal epithelia of the respiratory tract by PB or NaB is a novel discovery. This could mediate protection from

  13. Phenylbutyrate counteracts Shigella mediated downregulation of cathelicidin in rabbit lung and intestinal epithelia: a potential therapeutic strategy.

    Science.gov (United States)

    Sarker, Protim; Ahmed, Sultan; Tiash, Snigdha; Rekha, Rokeya Sultana; Stromberg, Roger; Andersson, Jan; Bergman, Peter; Gudmundsson, Gudmundur H; Agerberth, Birgitta; Raqib, Rubhana

    2011-01-01

    Cathelicidins and defensins are endogenous antimicrobial peptides (AMPs) that are downregulated in the mucosal epithelia of the large intestine in shigellosis. Oral treatment of Shigella infected rabbits with sodium butyrate (NaB) reduces clinical severity and counteracts the downregulation of cathelicidin (CAP-18) in the large intestinal epithelia. To develop novel regimen for treating infectious diseases by inducing innate immunity, we selected sodium 4-phenylbutyrate (PB), a registered drug for a metabolic disorder as a potential therapeutic candidate in a rabbit model of shigellosis. Since acute respiratory infections often cause secondary complications during shigellosis, the systemic effect of PB and NaB on CAP-18 expression in respiratory epithelia was also evaluated. The readouts were clinical outcomes, CAP-18 expression in mucosa of colon, rectum, lung and trachea (immunohistochemistry and real-time PCR) and release of the CAP-18 peptide/protein in stool (Western blot). Significant downregulation of CAP-18 expression in the epithelia of rectum and colon, the site of Shigella infection was confirmed. Interestingly, reduced expression of CAP-18 was also noticed in the epithelia of lung and trachea, indicating a systemic effect of the infection. This suggests a causative link to acute respiratory infections during shigellosis. Oral treatment with PB resulted in reduced clinical illness and upregulation of CAP-18 in the epithelium of rectum. Both PB and NaB counteracted the downregulation of CAP-18 in lung epithelium. The drug effect is suggested to be systemic as intravenous administration of NaB could also upregulate CAP-18 in the epithelia of lung, rectum and colon. Our results suggest that PB has treatment potential in human shigellosis. Enhancement of CAP-18 in the mucosal epithelia of the respiratory tract by PB or NaB is a novel discovery. This could mediate protection from secondary respiratory infections that frequently are the lethal causes in

  14. In silico analysis to identify vaccine candidates common to multiple serotypes of Shigella and evaluation of their immunogenicity

    KAUST Repository

    Pahil, Sapna

    2017-08-02

    Shigellosis or bacillary dysentery is an important cause of diarrhea, with the majority of the cases occurring in developing countries. Considering the high disease burden, increasing antibiotic resistance, serotype-specific immunity and the post-infectious sequelae associated with shigellosis, there is a pressing need of an effective vaccine against multiple serotypes of the pathogen. In the present study, we used bio-informatics approach to identify antigens shared among multiple serotypes of Shigella spp. This approach led to the identification of many immunogenic peptides. The five most promising peptides based on MHC binding efficiency were a putative lipoprotein (EL PGI I), a putative heat shock protein (EL PGI II), Spa32 (EL PGI III), IcsB (EL PGI IV) and a hypothetical protein (EL PGI V). These peptides were synthesized and the immunogenicity was evaluated in BALB/c mice by ELISA and cytokine assays. The putative heat shock protein (HSP) and the hypothetical protein elicited good humoral response, whereas putative lipoprotein, Spa32 and IcsB elicited good T-cell response as revealed by increased IFN-γ and TNF-α cytokine levels. The patient sera from confirmed cases of shigellosis were also evaluated for the presence of peptide specific antibodies with significant IgG and IgA antibodies against the HSP and the hypothetical protein, bestowing them as potential future vaccine candidates. The antigens reported in this study are novel and have not been tested as vaccine candidates against Shigella. This study offers time and cost-effective way of identifying unprecedented immunogenic antigens to be used as potential vaccine candidates. Moreover, this approach should easily be extendable to find new potential vaccine candidates for other pathogenic bacteria.

  15. Surveillance for Travel and Domestically Acquired Multidrug-Resistant Human Shigella Infections-Pennsylvania, 2006-2014.

    Science.gov (United States)

    Li, Yu Lung; Tewari, Deepanker; Yealy, Courtney C; Fardig, David; M'ikanatha, Nkuchia M

    2016-01-01

    Shigellosis is a leading cause of enteric infections in the United States. We compared antimicrobial resistance in Shigella infections related to overseas travel (travel-associated) and in those acquired domestically by analyzing antimicrobial resistance patterns, geographic distributions, and pulsed-field gel electrophoresis (PFGE) patterns. We tested samples (n = 204) from a collection of isolates recovered from patients in Pennsylvania between 2006 and 2014. Isolates were grouped into travel- and non-travel-associated categories. Eighty-one (79.4%) of the Shigella isolates acquired during international travel were resistant to multiple antibiotics compared to 53 (52.1%) of the infections transmitted in domestic settings. A majority (79.4%) of isolates associated with international travel demonstrated resistance to aminoglycosides and tetracyclines, whereas 47 (46.1%) of the infections acquired domestically were resistant to tetracycline. Almost all isolates (92.2%) transmitted in domestic settings were resistant to aminoglycosides, and 5 isolates from adult male patients were resistant to azithromycin, a drug often used for empiric treatment of severe shigellosis. Twenty (19.6%) isolates associated with illnesses acquired during overseas travel in 4 countries were resistant to quinolones. One S. sonnei PFGE pattern was traced to a multidrug-resistant isolate acquired overseas that had caused a multistate outbreak of shigellosis, suggesting global dissemination of a drug-resistant species. Resistance to certain drugs-for example, tetracycline-increased in both overseas- and domestic-acquired infections during the study period. The prevalence of resistance to macrolides (azithromycin) and third-generation cephalosporins (ceftriaxone) was less than 1%; however, efforts to better monitor changes in drug resistance over time combined with increased antimicrobial stewardship are essential at the local, national, and global levels.

  16. Selección de cepas de Shigella sonnei para el desarrollo de una vacuna efectiva contra la shigellosis

    Directory of Open Access Journals (Sweden)

    Olga M. Martínez

    2008-12-01

    Full Text Available En el Instituto Finlay se desarrolló una metodología de trabajo que contribuyó a la selección de cepas de Shigella sonnei como posibles candidatos vacunales contra la shigellosis. Las cepas investigadas, donadas por el Centro Provincial de Higiene y Epidemiología de Ciudad de La Habana, se caracterizaron según los métodos convencionales. La identificación del serogrupo y serotipo se realizó por aglutinación en láminas portaobjetos con antisueros comerciales; mientras que para el estudio de la susceptibilidad antimicrobiana se utilizó el DIRAMIC 10, un equipo semiautomatizado que proporcionó los resultados 4 horas después de su realización. Se investigó también la presencia de plásmidos de virulencia, por el crecimiento de Shigella spp. en medio de agar Triptona Soya con Rojo Congo al 0,025%, así como la expresión de las proteínas de la membrana externa en SDS-PAGE; para las pruebas de virulencia y potencia se emplearon los modelos animales (modelo ratón-pulmón y Test de Sereny. Los resultados obtenidos con la metodología utilizada permitieron la selección de la cepa de S. sonnei A-04 como la más adecuada para la obtención del posible candidato vacunal.

  17. In silico analysis to identify vaccine candidates common to multiple serotypes of Shigella and evaluation of their immunogenicity

    KAUST Repository

    Pahil, Sapna; Taneja, Neelam; Ansari, Hifzur Rahman; Raghava, G. P. S.

    2017-01-01

    Shigellosis or bacillary dysentery is an important cause of diarrhea, with the majority of the cases occurring in developing countries. Considering the high disease burden, increasing antibiotic resistance, serotype-specific immunity and the post-infectious sequelae associated with shigellosis, there is a pressing need of an effective vaccine against multiple serotypes of the pathogen. In the present study, we used bio-informatics approach to identify antigens shared among multiple serotypes of Shigella spp. This approach led to the identification of many immunogenic peptides. The five most promising peptides based on MHC binding efficiency were a putative lipoprotein (EL PGI I), a putative heat shock protein (EL PGI II), Spa32 (EL PGI III), IcsB (EL PGI IV) and a hypothetical protein (EL PGI V). These peptides were synthesized and the immunogenicity was evaluated in BALB/c mice by ELISA and cytokine assays. The putative heat shock protein (HSP) and the hypothetical protein elicited good humoral response, whereas putative lipoprotein, Spa32 and IcsB elicited good T-cell response as revealed by increased IFN-γ and TNF-α cytokine levels. The patient sera from confirmed cases of shigellosis were also evaluated for the presence of peptide specific antibodies with significant IgG and IgA antibodies against the HSP and the hypothetical protein, bestowing them as potential future vaccine candidates. The antigens reported in this study are novel and have not been tested as vaccine candidates against Shigella. This study offers time and cost-effective way of identifying unprecedented immunogenic antigens to be used as potential vaccine candidates. Moreover, this approach should easily be extendable to find new potential vaccine candidates for other pathogenic bacteria.

  18. In silico analysis to identify vaccine candidates common to multiple serotypes of Shigella and evaluation of their immunogenicity.

    Science.gov (United States)

    Pahil, Sapna; Taneja, Neelam; Ansari, Hifzur Rahman; Raghava, G P S

    2017-01-01

    Shigellosis or bacillary dysentery is an important cause of diarrhea, with the majority of the cases occurring in developing countries. Considering the high disease burden, increasing antibiotic resistance, serotype-specific immunity and the post-infectious sequelae associated with shigellosis, there is a pressing need of an effective vaccine against multiple serotypes of the pathogen. In the present study, we used bio-informatics approach to identify antigens shared among multiple serotypes of Shigella spp. This approach led to the identification of many immunogenic peptides. The five most promising peptides based on MHC binding efficiency were a putative lipoprotein (EL PGI I), a putative heat shock protein (EL PGI II), Spa32 (EL PGI III), IcsB (EL PGI IV) and a hypothetical protein (EL PGI V). These peptides were synthesized and the immunogenicity was evaluated in BALB/c mice by ELISA and cytokine assays. The putative heat shock protein (HSP) and the hypothetical protein elicited good humoral response, whereas putative lipoprotein, Spa32 and IcsB elicited good T-cell response as revealed by increased IFN-γ and TNF-α cytokine levels. The patient sera from confirmed cases of shigellosis were also evaluated for the presence of peptide specific antibodies with significant IgG and IgA antibodies against the HSP and the hypothetical protein, bestowing them as potential future vaccine candidates. The antigens reported in this study are novel and have not been tested as vaccine candidates against Shigella. This study offers time and cost-effective way of identifying unprecedented immunogenic antigens to be used as potential vaccine candidates. Moreover, this approach should easily be extendable to find new potential vaccine candidates for other pathogenic bacteria.

  19. Rapid diagnosis of diarrhea caused by Shigella sonnei using dipsticks; comparison of rectal swabs, direct stool and stool culture.

    Directory of Open Access Journals (Sweden)

    Claudia Duran

    Full Text Available BACKGROUND: We evaluated a dipstick test for rapid detection of Shigella sonnei on bacterial colonies, directly on stools and from rectal swabs because in actual field situations, most pathologic specimens for diagnosis correspond to stool samples or rectal swabs. METHODOLOGY/PRINCIPAL FINDINGS: The test is based on the detection of S. sonnei lipopolysaccharide (LPS O-side chains using phase I-specific monoclonal antibodies coupled to gold particles, and displayed on a one-step immunochromatographic dipstick. A concentration as low as 5 ng/ml of LPS was detected in distilled water and in reconstituted stools in 6 minutes. This is the optimal time for lecture to avoid errors of interpretation. In distilled water and in reconstituted stools, an unequivocal positive reaction was obtained with 4 x 10(6 CFU/ml of S. sonnei. The specificity was 100% when tested with a battery of Shigella and different unrelated strains. When tested on 342 rectal swabs in Chile, specificity (281/295 was 95.3% (95% CI: 92.9% - 97.7% and sensitivity (47/47 was 100%. Stool cultures and the immunochromatographic test showed concordant results in 95.5 % of cases (328/342 in comparative studies. Positive and negative predictive values were 77% (95% CI: 65% - 86.5% and 100% respectively. When tested on 219 stools in Chile, Vietnam, India and France, specificity (190/198 was 96% (95% CI 92%-98% and sensitivity (21/21 was 100%. Stool cultures and the immunochromatographic test showed concordant results in 96.3 % of cases (211/219 in comparative studies. Positive and negative predictive values were 72.4% (95% CI 56.1%-88.6% and 100 %, respectively. CONCLUSION: This one-step dipstick test performed well for diagnosis of S. sonnei both on stools and on rectal swabs. These data confirm a preliminary study done in Chile.

  20. In silico analysis to identify vaccine candidates common to multiple serotypes of Shigella and evaluation of their immunogenicity.

    Directory of Open Access Journals (Sweden)

    Sapna Pahil

    Full Text Available Shigellosis or bacillary dysentery is an important cause of diarrhea, with the majority of the cases occurring in developing countries. Considering the high disease burden, increasing antibiotic resistance, serotype-specific immunity and the post-infectious sequelae associated with shigellosis, there is a pressing need of an effective vaccine against multiple serotypes of the pathogen. In the present study, we used bio-informatics approach to identify antigens shared among multiple serotypes of Shigella spp. This approach led to the identification of many immunogenic peptides. The five most promising peptides based on MHC binding efficiency were a putative lipoprotein (EL PGI I, a putative heat shock protein (EL PGI II, Spa32 (EL PGI III, IcsB (EL PGI IV and a hypothetical protein (EL PGI V. These peptides were synthesized and the immunogenicity was evaluated in BALB/c mice by ELISA and cytokine assays. The putative heat shock protein (HSP and the hypothetical protein elicited good humoral response, whereas putative lipoprotein, Spa32 and IcsB elicited good T-cell response as revealed by increased IFN-γ and TNF-α cytokine levels. The patient sera from confirmed cases of shigellosis were also evaluated for the presence of peptide specific antibodies with significant IgG and IgA antibodies against the HSP and the hypothetical protein, bestowing them as potential future vaccine candidates. The antigens reported in this study are novel and have not been tested as vaccine candidates against Shigella. This study offers time and cost-effective way of identifying unprecedented immunogenic antigens to be used as potential vaccine candidates. Moreover, this approach should easily be extendable to find new potential vaccine candidates for other pathogenic bacteria.

  1. The sudden dominance of blaCTX-M harbouring plasmids in Shigella spp. Circulating in Southern Vietnam.

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    Nhu Thi Khanh Nguyen

    2010-06-01

    Full Text Available Plasmid mediated antimicrobial resistance in the Enterobacteriaceae is a global problem. The rise of CTX-M class extended spectrum beta lactamases (ESBLs has been well documented in industrialized countries. Vietnam is representative of a typical transitional middle income country where the spectrum of infectious diseases combined with the spread of drug resistance is shifting and bringing new healthcare challenges.We collected hospital admission data from the pediatric population attending the hospital for tropical diseases in Ho Chi Minh City with Shigella infections. Organisms were cultured from all enrolled patients and subjected to antimicrobial susceptibility testing. Those that were ESBL positive were subjected to further investigation. These investigations included PCR amplification for common ESBL genes, plasmid investigation, conjugation, microarray hybridization and DNA sequencing of a bla(CTX-M encoding plasmid.We show that two different bla(CTX-M genes are circulating in this bacterial population in this location. Sequence of one of the ESBL plasmids shows that rather than the gene being integrated into a preexisting MDR plasmid, the bla(CTX-M gene is located on relatively simple conjugative plasmid. The sequenced plasmid (pEG356 carried the bla(CTX-M-24 gene on an ISEcp1 element and demonstrated considerable sequence homology with other IncFI plasmids.The rapid dissemination, spread of antimicrobial resistance and changing population of Shigella spp. concurrent with economic growth are pertinent to many other countries undergoing similar development. Third generation cephalosporins are commonly used empiric antibiotics in Ho Chi Minh City. We recommend that these agents should not be considered for therapy of dysentery in this setting.

  2. LATAR BELAKANG KARAKTERISTIK RESPONDED DALAM PENCEGAHAN PENYAKIT SHIGELLA/DISENTRI YANG DILAKUKAN OLEH MASYARAKAT DI JAKARTA UTARA

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    Kartika Handayani

    2012-11-01

    Full Text Available The Research was conducted in North Jakarta and Selected 2 district in Jakarta North that is Tanjung Priok and Koja district as a research region. About 300 respondents which include 140 men and 151 woman from Tanjung Priok district. In Koja district was taken 200 respondents that consist of 101 men and 99 woman. Data processing done with double entry, by using program ISSA (Integrated Survey Analysis and Analysis Data used SPSS (Statistic Package for Social Science. The Research shown 88,7%-89,2% prevent spicy food can overcome dysentery disease of, 55.2% improving clean water can be temporary prevention of dysentery disease, and 56,4%-56,6% personal hygiene able to handle dysentery disease forever. By repairing bathroom (usually used for bath, wash, dump faeces 57.1%-58.4% and fixing garbage 56,2%-57,2% can prevent dysentery disease temporary, while 97,2%-97,4% of drinking traditional medicine (jamu also happen the same thing with dysentery disease. Based on respondents, 96,5%-96,6% using its own medicine/ingredient will prevent dysentery disease. According respondents habit on wash hand about 84.4% respondents wash their hand firstly in the morning and 74.2% washing band before sleep but 64.4% respondents who never wash their band before get dressed. From this research inferential respondents belief to prevent eat spicy food, improving readily clean water, bathroom, garbage place, efficacious of traditional drink, ingredients, washing band habit can be major factors that can prevent community from dysentery disease. The research is part of social Behavior Culture in Overcome Shigella Disease in Jakarta. Keywords: Respondent, Preventing, Shigella Disease

  3. Nota sobre infecção por Salmonella sp. e Shigella sp. em bugios-ruivos, Alouatta clamitans Cabrera, 1940 (Primates: Atelidae mantidos em cativeiro

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    Júlio César de Souza Júnior

    2008-08-01

    Full Text Available Amostras de fezes de bugios-ruivos cativos foram investigadas quanto a presença de Salmonella sp. e Shigella sp. O padrão de sensibilidade a antibióticos foi testado. Este é o primeiro relato de infecção assintomática por Salmonella sp. nesta espécie. Não foi detectada infecção por Shigella sp. Destaca-se a importância de investigação em animais submetidos a translocação ou a reintrodução e a necessidade de inquéritos periódicos em populações cativas a fim de se evitar agravos ocupacionais.

  4. Shigella IpaH0722 E3 Ubiquitin Ligase Effector Targets TRAF2 to Inhibit PKC–NF-κB Activity in Invaded Epithelial Cells

    Science.gov (United States)

    Ashida, Hiroshi; Nakano, Hiroyasu; Sasakawa, Chihiro

    2013-01-01

    NF-κB plays a central role in modulating innate immune responses to bacterial infections. Therefore, many bacterial pathogens deploy multiple mechanisms to counteract NF-κB activation. The invasion of and subsequent replication of Shigella within epithelial cells is recognized by various pathogen recognition receptors as pathogen-associated molecular patterns. These receptors trigger innate defense mechanisms via the activation of the NF-κB signaling pathway. Here, we show the inhibition of the NF-κB activation by the delivery of the IpaH E3 ubiquitin ligase family member IpaH0722 using Shigella's type III secretion system. IpaH0722 dampens the acute inflammatory response by preferentially inhibiting the PKC-mediated activation of NF-κB by ubiquitinating TRAF2, a molecule downstream of PKC, and by promoting its proteasome-dependent degradation. PMID:23754945

  5. Development of a Flow Cytometry-Based Method for Rapid Detection of Escherichia coli and Shigella Spp. Using an Oligonucleotide Probe

    Science.gov (United States)

    Xue, Yong; Wilkes, Jon G.; Moskal, Ted J.; Williams, Anna J.; Cooper, Willie M.; Nayak, Rajesh; Rafii, Fatemeh; Buzatu, Dan A.

    2016-01-01

    Standard methods to detect Escherichia coli contamination in food use the polymerase chain reaction (PCR) and agar culture plates. These methods require multiple incubation steps and take a long time to results. An improved rapid flow-cytometry based detection method was developed, using a fluorescence-labeled oligonucleotide probe specifically binding a16S rRNA sequence. The method positively detected 51 E. coli isolates as well as 4 Shigella species. All 27 non-E. coli strains tested gave negative results. Comparison of the new genetic assay with a total plate count (TPC) assay and agar plate counting indicated similar sensitivity, agreement between cytometry cell and colony counts. This method can detect a small number of E.coli cells in the presence of large numbers of other bacteria. This method can be used for rapid, economical, and stable detection of E. coli and Shigella contamination in the food industry and other contexts. PMID:26913737

  6. Development of a Flow Cytometry-Based Method for Rapid Detection of Escherichia coli and Shigella Spp. Using an Oligonucleotide Probe.

    Directory of Open Access Journals (Sweden)

    Yong Xue

    Full Text Available Standard methods to detect Escherichia coli contamination in food use the polymerase chain reaction (PCR and agar culture plates. These methods require multiple incubation steps and take a long time to results. An improved rapid flow-cytometry based detection method was developed, using a fluorescence-labeled oligonucleotide probe specifically binding a16S rRNA sequence. The method positively detected 51 E. coli isolates as well as 4 Shigella species. All 27 non-E. coli strains tested gave negative results. Comparison of the new genetic assay with a total plate count (TPC assay and agar plate counting indicated similar sensitivity, agreement between cytometry cell and colony counts. This method can detect a small number of E.coli cells in the presence of large numbers of other bacteria. This method can be used for rapid, economical, and stable detection of E. coli and Shigella contamination in the food industry and other contexts.

  7. Vigilancia en red de los serotipos y la susceptibilidad antimicrobiana de Salmonella spp., Shigella spp. Y Vibrio cholerae O1, 1997 - 1999

    Directory of Open Access Journals (Sweden)

    Nélida Muñoz

    2000-09-01

    Full Text Available En 1997, el Grupo de Microbiología del INS estableció un programa en red con los Laboratorios de Salud Pública (LSP del país y el apoyo de la OPS, para la vigilancia de los principales patógenos causantes de enfermedad diarreica aguda. El objetivo fue conocer los serotipos y los patrones de resistencia antimicrobiana de Salmonella spp., Shigella spp. y Vibrio cholerae O1. Los aislamientos fueron confirmados de acuerdo con los esquemas de identificación bioquímica y serológica estandarizados y la determinación de la susceptibilidad antimicrobiana se realizó por la técnica de difusión de disco (Kirby-Bauer. De 1997 a 1999, participaron 22 LSP con el envio de 976 aislamientos, 96% de origen clínico y 4% de alimentos; 34% Salmonella spp., 23% Shigella spp. y 42% V. cholerae 01. La distribución por serotipo de Salmonella fue 39% S. Enteritidis, 27% S. Typhimurium, 9% grupo El, 5% S. Typhi y 20% otros serotipos; de los aislamientos de Shigella, 67% fueron S. grupo flexneriza, 30% S sonnei, 2% S. dysenteriae y 1% S. boydii. Para V. cholerae 01, 99% fue serotipo Ogawa. La susceptibilidad antimicrobiana determinó que 56% de los aislamientos de Salmonella eran resistentes y 22% multirresistentes, con un patrón predominante de ampicilina, tetraciclina y trimetoprim-sulfa (SXT. De los aislamientos de Shigella, 97% fueron resistentes y 57% multirresistentes, con un patrón de ampicilina, tetraciclina, cloranfenicol y SXT. No se observaron cambios en la susceptibilidad de V. cholerae O1. Este estudio enfatiza la importancia de continuar con el programa de vigilancia, para conocer la epidemiologia de la EDA en Colombia, darle un tratamiento óptimo a estas infecciones y poder diseñar programas para disminuir la diseminación de bacterias resistentes.

  8. Evaluation of immunogenicity and protective efficacy of orally delivered Shigella type III secretion system proteins IpaB and IpaD.

    Science.gov (United States)

    Heine, Shannon J; Diaz-McNair, Jovita; Martinez-Becerra, Francisco J; Choudhari, Shyamal P; Clements, John D; Picking, Wendy L; Pasetti, Marcela F

    2013-06-19

    Shigella spp. are food- and water-borne pathogens that cause shigellosis, a severe diarrheal and dysenteric disease that is associated with a high morbidity and mortality in resource-poor countries. No licensed vaccine is available to prevent shigellosis. We have recently demonstrated that Shigella invasion plasmid antigens (Ipas), IpaB and IpaD, which are components of the bacterial type III secretion system (TTSS), can prevent infection in a mouse model of intranasal immunization and lethal pulmonary challenge. Because they are conserved across Shigella spp. and highly immunogenic, these proteins are excellent candidates for a cross-protective vaccine. Ideally, such a vaccine could be administered to humans orally to induce mucosal and systemic immunity. In this study, we investigated the immunogenicity and protective efficacy of Shigella IpaB and IpaD administered orally with a double mutant of the Escherichia coli heat labile toxin (dmLT) as a mucosal adjuvant. We characterized the immune responses induced by oral vs. intranasal immunization and the protective efficacy using a mouse pulmonary infection model. Serum IgG and fecal IgA against IpaB were induced after oral immunization. These responses, however, were lower than those obtained after intranasal immunization despite a 100-fold dosage increase. The level of protection induced by oral immunization with IpaB and IpaD was 40%, while intranasal immunization resulted in 90% protective efficacy. IpaB- and IpaD-specific IgA antibody-secreting cells in the lungs and spleen and T-cell-derived IL-2, IL-5, IL-17 and IL-10 were associated with protection. These results demonstrate the immunogenicity of orally administered IpaB and IpaD and support further studies in humans. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. Cloning and Expression of Fusion Genes of Domain A-1 Protective Antigen of Bacillus Anthracis and Shigella Enterotoxin B Subunit (Stxb In E. Coil

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    AH ahmadi

    2015-02-01

    Conclusion: The findings of the current study revealed that this antigen can be raised as an anti-cancer and recombinant vaccine candidate against types of Shigella, Escherichia coli and Bacillus anthracis which can be due to such factors as identification of antigen(PA by antibody PA20, its apoptosis induction properties, property of immunogenicity, adjuvant and delivery of STxB protein and high expression levels of Gb3 in human cancer cells.

  10. Deoxycholate-Enhanced Shigella Virulence Is Regulated by a Rare π-Helix in the Type Three Secretion System Tip Protein IpaD.

    Science.gov (United States)

    Bernard, Abram R; Jessop, T Carson; Kumar, Prashant; Dickenson, Nicholas E

    2017-12-12

    Type three secretion systems (T3SS) are specialized nanomachines that support infection by injecting bacterial proteins directly into host cells. The Shigella T3SS has uniquely evolved to sense environmental levels of the bile salt deoxycholate (DOC) and upregulate virulence in response to DOC. In this study, we describe a rare i + 5 hydrogen bonding secondary structure element (π-helix) within the type three secretion system tip protein IpaD that plays a critical role in DOC-enhanced virulence. Specifically, engineered mutations within the π-helix altered the pathogen's response to DOC, with one mutant construct in particular exhibiting an unprecedented reduction in virulence following DOC exposure. Fluorescence polarization binding assays showed that these altered DOC responses are not the result of differences in affinity between IpaD and DOC, but rather differences in the DOC-dependent T3SS tip maturation resulting from binding of IpaD to translocator/effector protein IpaB. Together, these findings begin to uncover the complex mechanism of DOC-enhanced Shigella virulence while identifying an uncommon structural element that may provide a much needed target for non-antibiotic treatment of Shigella infection.

  11. Study of the conditions of activation and stabilization of Shigella sonnei 47 DNA methylases in the process of fractionation, purification, and during storage

    International Nuclear Information System (INIS)

    Suchkov, S.V.; Lopatina, N.G.; Arutyunyan, E.E.; Nikol'skaya, I.I.; Debov, S.S.

    1987-01-01

    A comparative investigation was made of the factors of activation and conditions of stabilization of partially purified and individual fractions of DNA methylases of the strain Shigella sonnei 47. The influence of the temperature system, glycerin, albumin, protease inhibitors, divalent metal ions, as well as the conditions of storage at the value of the isoelectric point of the protein on the activity of the enzymes of methylation was studied. It was shown that the effects of activating factors and levels of stabilization differ appreciably, depending on the degree of purification and the composition of the enzyme preparations. It was established that glycerin is ineffective as a stabilizing agent. It was shown that of all the divalent cations studied the only activator universal for the methylases of Shigella sonnei 47 is Ca 2+ ions. A pronounced stabilizing effect of albumin on the activity of these DNA methylases was demonstrated. With the exception of one enzymatic fraction, the protease inhibitors have virtually no effect on the level of methylating activity of the preparations. The phenomenon of spontaneous fluctuations of the methylating activity of Shigella sonnei 47 enzyme preparations during storage is described

  12. CTX-M extended-spectrum β-lactamase-producing Klebsiella spp, Salmonella spp, Shigella spp and Escherichia coli isolates in Iranian hospitals.

    Science.gov (United States)

    Bialvaei, Abed Zahedi; Kafil, Hossein Samadi; Asgharzadeh, Mohammad; Aghazadeh, Mohammad; Yousefi, Mehdi

    2016-01-01

    This study was conducted in Iran in order to assess the distribution of CTX-M type ESBLs producing Enterobacteriaceae. From January 2012 to December 2013, totally 198 E. coli, 139 Klebsiella spp, 54 Salmonella spp and 52 Shigella spp from seven hospitals of six provinces in Iran were screened for resistance to extended-spectrum cephalosporins. After identification and susceptibility testing, isolates presenting multiple-drug resistance (MDR) were evaluated for ESBL production by the disk combination method and by Etest using (cefotaxime and cefotaxime plus clavulanic acid). All isolates were also screened for blaCTX-M using conventional PCR. A total of 42.92%, 33.81%, 14.81% and 7.69% of the E. coli, Klebsiella spp, Salmonella spp and Shigella spp isolates were MDR, respectively. The presence of CTX-M enzyme among ESBL-producing isolates was 85.18%, 77.7%, 50%, and 66.7%, in E. coli, Klebsiella spp, Salmonella spp and Shigella spp respectively. The overall presence of CTX-M genes in Enterobacteriaceae was 15.4% and among the resistant isolates was 47.6%. This study indicated that resistance to β-lactams mediated by CTX-M enzymes in Iran had similar pattern as in other parts of the world. In order to control the spread of resistance, comprehensive studies and programs are needed. Copyright © 2016 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

  13. Komposisi Kimia dan Uji Aktivitas Antibakteri Minyak Kemangi (Ocimum americanum L. Terhadap Bakteri Escherichia coli, Shigella sonnei, dan Salmonella enteritidis

    Directory of Open Access Journals (Sweden)

    Asep Kadarohman

    2011-06-01

    Full Text Available The chemical composition and antibacterial activity of basil oil (Ocimum americanum L. against Escherichia coli, Shigellasonnei and Salmonella enteritidis have been determined. Basil oils were isolated from leaves and stems of basil (Ocimum americanumL. with percolation method and analyzed by FTIR and GC-MS spectrometry. The antibacterial activity of basil oils were obtained byAgar diffusion method with various concentration (v/v 2, 4, 6, 8, and 10% with ethanol p.a. as negative control, thiamfenicol, andtetracycline 500 mg as positive control. The produces essential oils from leaves and stems of basil by percolation are 1.06 and 0.22%,respectively. There are 22 components of basil oil were identifi ed, with a major component are citral (35.58% and neral (29.56% .Basil oil has not effectively against Escherichia coli and Shigella sonnei but effectively against Salmonella enteritidis at concentration 8 and 10%, with inhibition zone diameter are 10.25 and 10.93 mm respectively.

  14. ORF Alignment: NC_004741 [GENIUS II[Archive

    Lifescience Database Archive (English)

    Full Text Available regulator of genes in aerobic pathways (sensors, ... ArcB and CpxA) [Shigella flexneri 2a str. 301] ... ... gb|AAN45846.2| negative response regulator of genes in ... aerobic pathways (sensors, ArcB...esponse ... regulator of genes in aerobic pathways (sensors, ArcB ... and CpxA) [Shigella flex...in aerobic pathways ... (sensors, ArcB and CpxA) [Shigella flexneri 2a str. ... 2457T] gb|AAN8... ... negative response regulator of genes in aerobic ... pathways, (sensors

  15. ORF Alignment: NC_003197 [GENIUS II[Archive

    Lifescience Database Archive (English)

    Full Text Available regulator of genes in aerobic pathways (sensors, ... ArcB and CpxA) [Shigella flexneri 2a str. 301] ... ... gb|AAN45846.2| negative response regulator of genes in ... aerobic pathways (sensors, ArcB...esponse ... regulator of genes in aerobic pathways (sensors, ArcB ... and CpxA) [Shigella flex...in aerobic pathways ... (sensors, ArcB and CpxA) [Shigella flexneri 2a str. ... 2457T] gb|AAN8... ... negative response regulator of genes in aerobic ... pathways, (sensors

  16. ORF Alignment: NC_004431 [GENIUS II[Archive

    Lifescience Database Archive (English)

    Full Text Available regulator of genes in aerobic pathways (sensors, ... ArcB and CpxA) [Shigella flexneri 2a str. 301] ... ... gb|AAN45846.2| negative response regulator of genes in ... aerobic pathways (sensors, ArcB...esponse ... regulator of genes in aerobic pathways (sensors, ArcB ... and CpxA) [Shigella flex...in aerobic pathways ... (sensors, ArcB and CpxA) [Shigella flexneri 2a str. ... 2457T] gb|AAN8... ... negative response regulator of genes in aerobic ... pathways, (sensors

  17. ORF Alignment: NC_006905 [GENIUS II[Archive

    Lifescience Database Archive (English)

    Full Text Available regulator of genes in aerobic pathways (sensors, ... ArcB and CpxA) [Shigella flexneri 2a str. 301] ... ... gb|AAN45846.2| negative response regulator of genes in ... aerobic pathways (sensors, ArcB...esponse ... regulator of genes in aerobic pathways (sensors, ArcB ... and CpxA) [Shigella flex...in aerobic pathways ... (sensors, ArcB and CpxA) [Shigella flexneri 2a str. ... 2457T] gb|AAN8... ... negative response regulator of genes in aerobic ... pathways, (sensors

  18. ORF Alignment: NC_004337 [GENIUS II[Archive

    Lifescience Database Archive (English)

    Full Text Available regulator of genes in aerobic pathways (sensors, ... ArcB and CpxA) [Shigella flexneri 2a str. 301] ... ... gb|AAN45846.2| negative response regulator of genes in ... aerobic pathways (sensors, ArcB...esponse ... regulator of genes in aerobic pathways (sensors, ArcB ... and CpxA) [Shigella flex...in aerobic pathways ... (sensors, ArcB and CpxA) [Shigella flexneri 2a str. ... 2457T] gb|AAN8... ... negative response regulator of genes in aerobic ... pathways, (sensors

  19. ORF Alignment: NC_004631 [GENIUS II[Archive

    Lifescience Database Archive (English)

    Full Text Available regulator of genes in aerobic pathways (sensors, ... ArcB and CpxA) [Shigella flexneri 2a str. 301] ... ... gb|AAN45846.2| negative response regulator of genes in ... aerobic pathways (sensors, ArcB...esponse ... regulator of genes in aerobic pathways (sensors, ArcB ... and CpxA) [Shigella flex...in aerobic pathways ... (sensors, ArcB and CpxA) [Shigella flexneri 2a str. ... 2457T] gb|AAN8... ... negative response regulator of genes in aerobic ... pathways, (sensors

  20. ORF Alignment: NC_002655 [GENIUS II[Archive

    Lifescience Database Archive (English)

    Full Text Available regulator of genes in aerobic pathways (sensors, ... ArcB and CpxA) [Shigella flexneri 2a str. 301] ... ... gb|AAN45846.2| negative response regulator of genes in ... aerobic pathways (sensors, ArcB...esponse ... regulator of genes in aerobic pathways (sensors, ArcB ... and CpxA) [Shigella flex...in aerobic pathways ... (sensors, ArcB and CpxA) [Shigella flexneri 2a str. ... 2457T] gb|AAN8... ... negative response regulator of genes in aerobic ... pathways, (sensors

  1. ORF Alignment: NC_002695 [GENIUS II[Archive

    Lifescience Database Archive (English)

    Full Text Available regulator of genes in aerobic pathways (sensors, ... ArcB and CpxA) [Shigella flexneri 2a str. 301] ... ... gb|AAN45846.2| negative response regulator of genes in ... aerobic pathways (sensors, ArcB...esponse ... regulator of genes in aerobic pathways (sensors, ArcB ... and CpxA) [Shigella flex...in aerobic pathways ... (sensors, ArcB and CpxA) [Shigella flexneri 2a str. ... 2457T] gb|AAN8... ... negative response regulator of genes in aerobic ... pathways, (sensors

  2. Structural and Biochemical Characterization of Spa47 Provides Mechanistic Insight into Type III Secretion System ATPase Activation and Shigella Virulence Regulation.

    Science.gov (United States)

    Burgess, Jamie L; Burgess, R Alan; Morales, Yalemi; Bouvang, Jenna M; Johnson, Sean J; Dickenson, Nicholas E

    2016-12-09

    Like many Gram-negative pathogens, Shigella rely on a complex type III secretion system (T3SS) to inject effector proteins into host cells, take over host functions, and ultimately establish infection. Despite these critical roles, the energetics and regulatory mechanisms controlling the T3SS and pathogen virulence remain largely unclear. In this study, we present a series of high resolution crystal structures of Spa47 and use the structures to model an activated Spa47 oligomer, finding that ATP hydrolysis may be supported by specific side chain contributions from adjacent protomers within the complex. Follow-up mutagenesis experiments targeting the predicted active site residues validate the oligomeric model and determined that each of the tested residues are essential for Spa47 ATPase activity, although they are not directly responsible for stable oligomer formation. Although N-terminal domain truncation was necessary for crystal formation, it resulted in strictly monomeric Spa47 that is unable to hydrolyze ATP, despite maintaining the canonical ATPase core structure and active site residues. Coupled with studies of ATPase inactive full-length Spa47 point mutants, we find that Spa47 oligomerization and ATP hydrolysis are needed for complete T3SS apparatus formation, a proper translocator secretion profile, and Shigella virulence. This work represents the first structure-function characterization of Spa47, uniquely complementing the multitude of included Shigella T3SS phenotype assays and providing a more complete understanding of T3SS ATPase-mediated pathogen virulence. Additionally, these findings provide a strong platform for follow-up studies evaluating regulation of Spa47 oligomerization in vivo as a much needed means of treating and perhaps preventing shigellosis. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  3. Structural and Biochemical Characterization of Spa47 Provides Mechanistic Insight into Type III Secretion System ATPase Activation and Shigella Virulence Regulation*

    Science.gov (United States)

    Burgess, Jamie L.; Burgess, R. Alan; Morales, Yalemi; Bouvang, Jenna M.; Johnson, Sean J.; Dickenson, Nicholas E.

    2016-01-01

    Like many Gram-negative pathogens, Shigella rely on a complex type III secretion system (T3SS) to inject effector proteins into host cells, take over host functions, and ultimately establish infection. Despite these critical roles, the energetics and regulatory mechanisms controlling the T3SS and pathogen virulence remain largely unclear. In this study, we present a series of high resolution crystal structures of Spa47 and use the structures to model an activated Spa47 oligomer, finding that ATP hydrolysis may be supported by specific side chain contributions from adjacent protomers within the complex. Follow-up mutagenesis experiments targeting the predicted active site residues validate the oligomeric model and determined that each of the tested residues are essential for Spa47 ATPase activity, although they are not directly responsible for stable oligomer formation. Although N-terminal domain truncation was necessary for crystal formation, it resulted in strictly monomeric Spa47 that is unable to hydrolyze ATP, despite maintaining the canonical ATPase core structure and active site residues. Coupled with studies of ATPase inactive full-length Spa47 point mutants, we find that Spa47 oligomerization and ATP hydrolysis are needed for complete T3SS apparatus formation, a proper translocator secretion profile, and Shigella virulence. This work represents the first structure-function characterization of Spa47, uniquely complementing the multitude of included Shigella T3SS phenotype assays and providing a more complete understanding of T3SS ATPase-mediated pathogen virulence. Additionally, these findings provide a strong platform for follow-up studies evaluating regulation of Spa47 oligomerization in vivo as a much needed means of treating and perhaps preventing shigellosis. PMID:27770024

  4. Immunization with r-Lactococcus lactis expressing outer membrane protein A of Shigella dysenteriae type-1: evaluation of oral and intranasal route of administration.

    Science.gov (United States)

    Yagnik, B; Sharma, D; Padh, H; Desai, P

    2017-02-01

    To evaluate the comparative immunogenic potential of food grade Lactococcus lactis expressing outer membrane protein A (OmpA) of Shigella dysenteriae type-1 (SD-1) when administered either orally or intranasally. OmpA of SD-1 was cloned and expressed first in Escherichia coli and then in L. lactis. Presence of recombinant gene was confirmed by restriction enzyme digestion and immunoblot analysis. Using immobilized metal affinity chromatography, OmpA was purified from recombinant E. coliBL21 (DE3) and subcutaneously administered in BALB/c mice. Detection of OmpA-specific IgG antibodies by enzyme-linked immunosorbent assay (ELISA) confirmed the immunogenicity of OmpA. In order to establish r-L. lactis as a mucosal delivery vehicle, it was administered orally and nasally in BALB/c mice. Serum IgG and faecal IgA were assessed through ELISA to compare the relative potential of immunization routes and immunogenic potential of r-L. lactis. Immunization via the oral route proved superior to intranasal exposure. Recombinant L. lactis expressing OmpA of SD-1 was found to be immunogenic. Oral administration of r-L. lactis elicited higher systemic and mucosal immune response when compared with the nasal route. Using food grade recombinant L. lactis has implications in the development of a prophylactic against multidrug-resistant Shigella, which can be used as a prospective vaccine candidate. Evaluating mucosal routes of immunization demonstrated that the oral route of administration elicited better immune response against OmpA of Shigella. © 2016 The Society for Applied Microbiology.

  5. Force Protection Technologies for the 2010-2020 Timeframe

    Science.gov (United States)

    2003-11-01

    V11. Marburg virus V12. Monkey pox virus Viruses V13. Rift Valley fever virus V14. Tick-borne encephalitis virus (Russian Spring-Summer...pseudomallei (pseudomonas pseudomallei) B10. Salmonella typhi B11. Shigella dysenteriae Bacteria B11. Vibrio cholerae Sensor Section, ASB...and shown to detect Shigella flexneri and Shigella dysenteriae genes. Each class of threat agent is likely to give a distinct hybridization pattern

  6. Dipstick test for rapid diagnosis of Shigella dysenteriae 1 in bacterial cultures and its potential use on stool samples.

    Directory of Open Access Journals (Sweden)

    Neelam Taneja

    Full Text Available BACKGROUND: We describe a test for rapid detection of S. dysenteriae 1 in bacterial cultures and in stools, at the bedside of patients. METHODOLOGY/PRINCIPAL FINDINGS: The test is based on the detection of S. dysenteriae 1 lipopolysaccharide (LPS using serotype 1-specific monoclonal antibodies coupled to gold particles and displayed on a one-step immunochromatographic dipstick. A concentration as low as 15 ng/ml of LPS was detected in distilled water and in reconstituted stools in 10 minutes. In distilled water and in reconstituted stools, an unequivocal positive reaction was obtained with 1.6×10⁶ CFU/ml and 4.9×10⁶ CFU/ml of S. dysenteriae 1, respectively. Optimal conditions to read the test have been determined to limit the risk of ambiguous results due to appearance of a faint yellow test band in some negative samples. The specificity was 100% when tested with a battery of Shigella and unrelated strains in culture. When tested on 328 clinical samples in India, Vietnam, Senegal and France by laboratory technicians and in Democratic Republic of Congo by a field technician, the specificity (312/316 was 98.7% (95% CI:96.6-99.6% and the sensitivity (11/12 was 91.7% (95% CI:59.8-99.6%. Stool cultures and the immunochromatographic test showed concordant results in 98.4 % of cases (323/328 in comparative studies. Positive and negative predictive values were 73.3% (95% CI:44.8-91.1% and 99.7% (95% CI:98-100%. CONCLUSION: The initial findings presented here for a simple dipstick-based test to diagnose S. dysenteriae 1 demonstrates its promising potential to become a powerful tool for case management and epidemiological surveys.

  7. Molecular cloning and biologically active production of IpaD N-terminal region.

    Science.gov (United States)

    Hesaraki, Mahdi; Saadati, Mojtaba; Honari, Hossein; Olad, Gholamreza; Heiat, Mohammad; Malaei, Fatemeh; Ranjbar, Reza

    2013-07-01

    Shigella is known as pathogenic intestinal bacteria in high dispersion and pathogenic bacteria due to invasive plasmid antigen (Ipa). So far, a number of Ipa proteins have been studied to introduce a new candidate vaccine. Here, for the first time, we examined whether the N-terminal region of IpaD(72-162) could be a proper candidate for Shigella vaccine. Initially, the DNA sequence coding N-terminal region was isolated by PCR from Shigella dysenteriae type I and cloned into pET-28a expression vector. Then, the heterologous protein was expressed, optimized and purified by affinity Ni-NTA column. Western blot analysis using, His-tag and IpaD(72-162) polyclonal antibodies, confirmed the purity and specificity of the recombinant protein, respectively. Subsequently, the high immunogenicity of the antigen was shown by ELISA. The results of the sereny test in Guinea pigs showed that IpaD(72-162) provides a protective system against Shigella flexneri 5a and S. dysenteriae type I. Copyright © 2013. Published by Elsevier Ltd.

  8. Förster Resonance Energy Transfer (FRET as a Tool for Dissecting the Molecular Mechanisms for Maturation of the Shigella Type III Secretion Needle Tip Complex

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    William D. Picking

    2012-11-01

    Full Text Available Förster resonance energy transfer (FRET provides a powerful tool for monitoring intermolecular interactions and a sensitive technique for studying Å-level protein conformational changes. One system that has particularly benefited from the sensitivity and diversity of FRET measurements is the maturation of the Shigella type III secretion apparatus (T3SA needle tip complex. The Shigella T3SA delivers effector proteins into intestinal cells to promote bacterial invasion and spread. The T3SA is comprised of a basal body that spans the bacterial envelope and a needle with an exposed tip complex that matures in response to environmental stimuli. FRET measurements demonstrated bile salt binding by the nascent needle tip protein IpaD and also mapped resulting structural changes which led to the recruitment of the translocator IpaB. At the needle tip IpaB acts as a sensor for host cell contact but prior to secretion, it is stored as a heterodimeric complex with the chaperone IpgC. FRET analyses showed that chaperone binding to IpaB’s N-terminal domain causes a conformational change in the latter. These FRET analyses, with other biophysical methods, have been central to understanding T3SA maturation and will be highlighted, focusing on the details of the FRET measurements and the relevance to this particular system.

  9. Prevalence and characterisation of plasmid-mediated quinolone resistance and mutations in the gyrase and topoisomerase IV genes among Shigella isolates from Henan, China, between 2001 and 2008.

    Science.gov (United States)

    Yang, Haiyan; Duan, Guangcai; Zhu, Jingyuan; Zhang, Weidong; Xi, Yuanlin; Fan, Qingtang

    2013-08-01

    A total of 293 Shigella isolates were isolated from patients with diarrhoea in four villages of Henan, China. This study investigated the prevalence of the plasmid-mediated quinolone resistance (PMQR) genes qnrA, qnrB, qnrS, qepA and aac(6')-Ib-cr and compared the polymorphic quinolone resistance-determining regions (QRDRs) of gyrA, gyrB, parC and parE. Of the isolates, 292 were found to be resistant to nalidixic acid and pipemidic acid, whereas 77 were resistant to ciprofloxacin (resistance rate of 26.3%). Resistance of the Shigella isolates to ciprofloxacin significantly increased from 2001 to 2008 (PShigella isolates are common in China. This study found that there was a significant increase in mutation rates of the QRDR and the resistant rates to ciprofloxacin. Other mechanisms may be present in the isolates that also contribute to their resistance to ciprofloxacin. Copyright © 2013 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.

  10. Wnt5a Signaling in Cancer

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    Marwa S. Asem

    2016-08-01

    Full Text Available Wnt5a is involved in activating several non-canonical WNT signaling pathways, through binding to different members of the Frizzled- and Ror-family receptors. Wnt5a signaling is critical for regulating normal developmental processes, including proliferation, differentiation, migration, adhesion and polarity. However, the aberrant activation or inhibition of Wnt5a signaling is emerging as an important event in cancer progression, exerting both oncogenic and tumor suppressive effects. Recent studies show the involvement of Wnt5a in regulating cancer cell invasion, metastasis, metabolism and inflammation. In this article, we review findings regarding the molecular mechanisms and roles of Wnt5a signaling in various cancer types, and highlight Wnt5a in ovarian cancer.

  11. In vivo versus in vitro protein abundance analysis of Shigella dysenteriae type 1 reveals changes in the expression of proteins involved in virulence, stress and energy metabolism

    Directory of Open Access Journals (Sweden)

    Donohue-Rolfe Arthur

    2011-06-01

    Full Text Available Abstract Background Shigella dysenteriae serotype 1 (SD1 causes the most severe form of epidemic bacillary dysentery. Quantitative proteome profiling of Shigella dysenteriae serotype 1 (SD1 in vitro (derived from LB cell cultures and in vivo (derived from gnotobiotic piglets was performed by 2D-LC-MS/MS and APEX, a label-free computationally modified spectral counting methodology. Results Overall, 1761 proteins were quantitated at a 5% FDR (false discovery rate, including 1480 and 1505 from in vitro and in vivo samples, respectively. Identification of 350 cytoplasmic membrane and outer membrane (OM proteins (38% of in silico predicted SD1 membrane proteome contributed to the most extensive survey of the Shigella membrane proteome reported so far. Differential protein abundance analysis using statistical tests revealed that SD1 cells switched to an anaerobic energy metabolism under in vivo conditions, resulting in an increase in fermentative, propanoate, butanoate and nitrate metabolism. Abundance increases of transcription activators FNR and Nar supported the notion of a switch from aerobic to anaerobic respiration in the host gut environment. High in vivo abundances of proteins involved in acid resistance (GadB, AdiA and mixed acid fermentation (PflA/PflB indicated bacterial survival responses to acid stress, while increased abundance of oxidative stress proteins (YfiD/YfiF/SodB implied that defense mechanisms against oxygen radicals were mobilized. Proteins involved in peptidoglycan turnover (MurB were increased, while β-barrel OM proteins (OmpA, OM lipoproteins (NlpD, chaperones involved in OM protein folding pathways (YraP, NlpB and lipopolysaccharide biosynthesis (Imp were decreased, suggesting unexpected modulations of the outer membrane/peptidoglycan layers in vivo. Several virulence proteins of the Mxi-Spa type III secretion system and invasion plasmid antigens (Ipa proteins required for invasion of colonic epithelial cells, and release

  12. Brote de gastroenteritis por el consumo de agua de suministro público causado por Shigella sonnei Waterborne outbreak of Shigella sonnei caused by consumption of public supply water

    Directory of Open Access Journals (Sweden)

    Pere Godoy

    2011-10-01

    -3 glasses per day (RR=4.3; CI 95%: 1.9-9.9 and in those drinking more than three glasses per day (RR=4.9; 95% CI: 2.2 -10.9. The chlorinator of mains water froze and stopped working. Six stool cultures were positive for Shigella sonnei. Conclusions: A waterborne outbreak of S. sonnei was caused by contamination of the public water supply. Investigation of illegal dumping of wastewater was recommended. Municipalities should ensure proper disinfection systems and prevent spillage near deposits.

  13. One Gene and Two Proteins: a Leaderless mRNA Supports the Translation of a Shorter Form of the Shigella VirF Regulator.

    Science.gov (United States)

    Di Martino, Maria Letizia; Romilly, Cédric; Wagner, E Gerhart H; Colonna, Bianca; Prosseda, Gianni

    2016-11-08

    VirF, an AraC-like activator, is required to trigger a regulatory cascade that initiates the invasive program of Shigella spp., the etiological agents of bacillary dysentery in humans. VirF expression is activated upon entry into the host and depends on many environmental signals. Here, we show that the virF mRNA is translated into two proteins, the major form, VirF 30 (30 kDa), and the shorter VirF 21 (21 kDa), lacking the N-terminal segment. By site-specific mutagenesis and toeprint analysis, we identified the translation start sites of VirF 30 and VirF 21 and showed that the two different forms of VirF arise from differential translation. Interestingly, in vitro and in vivo translation experiments showed that VirF 21 is also translated from a leaderless mRNA (llmRNA) whose 5' end is at position +309/+310, only 1 or 2 nucleotides upstream of the ATG84 start codon of VirF 21 The llmRNA is transcribed from a gene-internal promoter, which we identified here. Functional analysis revealed that while VirF 30 is responsible for activation of the virulence system, VirF 21 negatively autoregulates virF expression itself. Since VirF 21 modulates the intracellular VirF levels, this suggests that transcription of the llmRNA might occur when the onset of the virulence program is not required. We speculate that environmental cues, like stress conditions, may promote changes in virF mRNA transcription and preferential translation of llmRNA. Shigella spp. are a major cause of dysentery in humans. In bacteria of this genus, the activation of the invasive program involves a multitude of signals that act on all layers of the gene regulatory hierarchy. By controlling the essential genes for host cell invasion, VirF is the key regulator of the switch from the noninvasive to the invasive phenotype. Here, we show that the Shigella virF gene encodes two proteins of different sizes, VirF 30 and VirF 21 , that are functionally distinct. The major form, VirF 30 , activates the genes

  14. Multicenter evaluation of resistance patterns of Klebsiella pneumoniae, Escherichia coli, Salmonella spp and Shigella spp isolated from clinical specimens in Brazil: RESISTNET surveillance program

    Directory of Open Access Journals (Sweden)

    Carmen Paz Oplustil

    Full Text Available Surveillance programs are essential to detect the increase of antimicrobial resistance, and several different programs are being conducted in many countries. The RESISTNET is a surveillance program for bacterial resistance against several antimicrobial agents initiated in 1998 among Latin American countries. In Brazil, several centers were invited to join this surveillance and a total of 11 centers (6 from São Paulo and 5 from other states participated in the study. All results were analyzed using the WHONET program. A total of 894 Escherichia coli, 386 Klebsiella pneumoniae, 70 Shigella spp and 57 Salmonella spp strains were analyzed in this study from April, 1998, to April, 1999. Susceptibility testing was performed by the disk diffusion method using NCCLS 1998 guidelines for several different drugs. For all strains, imipenem was the most effective drug (100% of the strains were susceptible. Klebsiella pneumoniae presented a high resistance rate to ampicillin (96.4%. The rate of probable ESBL producers among K. pneumoniae strains was 36.3%, most of them being isolated from catheters (58.8%. Among all Escherichia coli strains analyzed, the highest resistance rate was found for trimethoprim/sulfamethoxazole (46.9% and the majority of the resistant strains were isolated from urine samples (47.8%. Among Salmonella spp, the resistance rates were low for all antibiotics tested. For Shigella spp strains there was a high resistance to trimethoprim/sulfamethoxazole (80.0%. No resistance to ceftriaxone was observed in these strains. Surveillance of antimicrobial resistance is critical for the successful management of infectious diseases. The results of this survey show significant resistance rates among these bacteria which are responsible for several types of human infections.

  15. Cloning and Expression of Phytase appA Gene from Shigella sp. CD2 in Pichia pastoris and Comparison of Properties with Recombinant Enzyme Expressed in E. coli.

    Directory of Open Access Journals (Sweden)

    Moushree Pal Roy

    Full Text Available The phytase gene appAS was isolated from Shigella sp. CD2 genomic library. The 3.8 kb DNA fragment contained 1299 bp open reading frame encoding 432 amino acid protein (AppAS with 22 amino acid signal peptide at N-terminal and three sites of N-glycosylation. AppAS contained the active site RHGXRXP and HDTN sequence motifs, which are conserved among histidine acid phosphatases. It showed maximum identity with phytase AppA of Escherichia coli and Citrobacter braakii. The appAS was expressed in Pichia pastoris and E. coli to produce recombinant phytase rAppAP and rAppAE, respectively. Purified glycosylated rAppAP and nonglycosylated rAppAE had specific activity of 967 and 2982 U mg(-1, respectively. Both had pH optima of 5.5 and temperature optima of 60°C. Compared with rAppAE, rAppAP was 13 and 17% less active at pH 3.5 and 7.5 and 11 and 18% less active at temperature 37 and 50°C, respectively; however, it was more active at higher incubation temperatures. Thermotolerance of rAppAP was 33% greater at 60°C and 24% greater at 70°C, when compared with rAppAE. Both the recombinant enzymes showed high specificity to phytate and resistance to trypsin. To our knowledge, this is the first report on cloning and expression of phytase from Shigella sp.

  16. Cloning and Expression of Phytase appA Gene from Shigella sp. CD2 in Pichia pastoris and Comparison of Properties with Recombinant Enzyme Expressed in E. coli.

    Science.gov (United States)

    Pal Roy, Moushree; Mazumdar, Deepika; Dutta, Subhabrata; Saha, Shyama Prasad; Ghosh, Shilpi

    2016-01-01

    The phytase gene appAS was isolated from Shigella sp. CD2 genomic library. The 3.8 kb DNA fragment contained 1299 bp open reading frame encoding 432 amino acid protein (AppAS) with 22 amino acid signal peptide at N-terminal and three sites of N-glycosylation. AppAS contained the active site RHGXRXP and HDTN sequence motifs, which are conserved among histidine acid phosphatases. It showed maximum identity with phytase AppA of Escherichia coli and Citrobacter braakii. The appAS was expressed in Pichia pastoris and E. coli to produce recombinant phytase rAppAP and rAppAE, respectively. Purified glycosylated rAppAP and nonglycosylated rAppAE had specific activity of 967 and 2982 U mg(-1), respectively. Both had pH optima of 5.5 and temperature optima of 60°C. Compared with rAppAE, rAppAP was 13 and 17% less active at pH 3.5 and 7.5 and 11 and 18% less active at temperature 37 and 50°C, respectively; however, it was more active at higher incubation temperatures. Thermotolerance of rAppAP was 33% greater at 60°C and 24% greater at 70°C, when compared with rAppAE. Both the recombinant enzymes showed high specificity to phytate and resistance to trypsin. To our knowledge, this is the first report on cloning and expression of phytase from Shigella sp.

  17. Inhibitory Activity of Lactid Acid Bacteria Isolated from Tape Waterlily Seed to Enteric Pathogenic Bacteria (Vibrio cholera, Salmonella typhi, Shigella disentri, and E.coli and Its’ Susceptibility to Antibiotic, Bile Salt and Acidic Condition

    Directory of Open Access Journals (Sweden)

    Iin Khusnul Khotimah

    2012-03-01

    Full Text Available The aim of this research was to observe inhibitory activity of LAB isolated from tape waterlily seed to enteric pathogenic bacteria (Vibrio cholera, Salmonella typhi, Shigella disentri, E.coli ATCC 25922 and it’s susceptibility to antibiotic, in bile salt and under acidic condition. Microbia in the tape ( a fermented product of waterlily seed to showed were Streptococcus thermophilus (IKH-1, Pediococcus pentosaceus (IKH-2 and Leuconostoc mesentroides (IKH-8. Streptococcus thermophillus showed inhibition against the growth of Shigella disentri with inhibition zones 16,28 mm, but did not against the growth of V. Cholera, S. typhi, E.coli. Pediococcus pentosaceus inhibit Vibrio cholera, dan Salmonella thypi with inhibition zones 18,59 mm dan 7,91 mm. So that, Leuconostoc mesenteroides inhibit Salmonella thypi with zones inhibits average 8,25 mm. Chloramfenicol at 0.05 mg concentrations did not show inhibition against the growth of isolated Streptococcus thermophillus, Pediococcus pentosaceus and Leuconostoc mesentroides. These isolates could survive too in bile salt (2% and acidified media (pH 3.   Keyword : The tape of  waterlily seed, LAB, probiotic and enteric pathogenic   KEMAMPUAN PENGHAMBATAN BAKTERI ASAM LAKTAT DARI TAPE BIJI TERATAI TERHADAP PATOGENIK ENTERIK (VIBRIO CHOLERA, SALMONELLA THYPI, SHIGELLA DISENTRI, E. COLI, ANTIBIOTIK, KETAHANANNYA TERHADAP BILE SALT DAN ASAM   ABSTRAK   Penelitian ini bertujuan untuk menguji kemampuan penghambatan bakteri asam laktat yang diisolasi dari tape biji teratai terhadap patogenik enterik (Vibrio cholera, Salmonella thypi, Shigella disentri, E. Coli ATCC 25922, antibiotik, bile salt dan asam. Jenis bakteri yang diketahui tumbuh selama fermentasi tape biji teratai adalah Streptococcus thermopilus (IKH-1, Pediococcus pentosaceus(IKH-2, dan Leuconostoc mesentroides (IKH-8. Pengamatan terhadap uji penghambatan patogenik enterik (Vibrio cholera, Salmonella thypi, Shigella disentri, dan E. Coli ATCC

  18. Zeolite 5A Catalyzed Etherification of Diphenylmethanol

    Science.gov (United States)

    Cooke, Jason; Henderson, Eric J.; Lightbody, Owen C.

    2009-01-01

    An experiment for the synthetic undergraduate laboratory is described in which zeolite 5A catalyzes the room temperature dehydration of diphenylmethanol, (C[subscript 6]H[subscript 5])[subscript 2]CHOH, producing 1,1,1',1'-tetraphenyldimethyl ether, (C[subscript 6]H[subscript 5])[subscript 2]CHOCH(C[subscript 6]H[subscript 5])[subscript 2]. The…

  19. ORF Alignment: NC_004741 [GENIUS II[Archive

    Lifescience Database Archive (English)

    Full Text Available NC_004741 gi|30064861 >1ogiA 15 282 6 231 1e-18 ... ref|NP_709648.2| ferrisiderophore... reductase, flavin reductase (NADPH:flavin ... oxidoreductase) [Shigella flexneri 2a str. 301] ... gb|AAN45355.2| ferri...higella ... flexneri 2a str. 301] ref|NP_839032.1| ferrisiderophore ... ... ... gb|AAP18843.1| ferrisiderophore reductase, flavin ... reductase (NADPH:flavin oxidoreducta

  20. ORF Alignment: NC_004337 [GENIUS II[Archive

    Lifescience Database Archive (English)

    Full Text Available NC_004337 gi|56480453 >1ogiA 15 282 6 231 1e-18 ... ref|NP_709648.2| ferrisiderophore... reductase, flavin reductase (NADPH:flavin ... oxidoreductase) [Shigella flexneri 2a str. 301] ... gb|AAN45355.2| ferri...higella ... flexneri 2a str. 301] ref|NP_839032.1| ferrisiderophore ... ... ... gb|AAP18843.1| ferrisiderophore reductase, flavin ... reductase (NADPH:flavin oxidoreducta

  1. ORF Alignment: NC_004337 [GENIUS II[Archive

    Lifescience Database Archive (English)

    Full Text Available NC_004337 gi|24113675 >1nbuA 1 118 5 120 2e-19 ... ref|NP_708185.1| D-erythro-7,8-dihydrone...opterin triphosphate epimerase [Shigella ... flexneri 2a str. 301] gb|AAN43892.1| ... D-erythro-7,8-dihydrone....1| ... D-erythro-7,8-dihydroneopterin triphosphate epimerase ... [...Shigella flexneri 2a str. 2457T] ref|NP_754732.1| ... D-erythro-7,8-dihydroneopterin triphosphate epi...merase ... [Escherichia coli CFT073] gb|AAP17710.1| ... D-erythro-7,8-dihydroneopterin triphos

  2. ORF Alignment: NC_002655 [GENIUS II[Archive

    Lifescience Database Archive (English)

    Full Text Available NC_002655 gi|15802850 >1nbuA 1 118 5 120 2e-19 ... ref|NP_708185.1| D-erythro-7,8-dihydrone...opterin triphosphate epimerase [Shigella ... flexneri 2a str. 301] gb|AAN43892.1| ... D-erythro-7,8-dihydrone....1| ... D-erythro-7,8-dihydroneopterin triphosphate epimerase ... [...Shigella flexneri 2a str. 2457T] ref|NP_754732.1| ... D-erythro-7,8-dihydroneopterin triphosphate epi...merase ... [Escherichia coli CFT073] gb|AAP17710.1| ... D-erythro-7,8-dihydroneopterin triphos

  3. ORF Alignment: NC_004431 [GENIUS II[Archive

    Lifescience Database Archive (English)

    Full Text Available NC_004431 gi|26248692 >1nbuA 1 118 5 120 2e-19 ... ref|NP_708185.1| D-erythro-7,8-dihydrone...opterin triphosphate epimerase [Shigella ... flexneri 2a str. 301] gb|AAN43892.1| ... D-erythro-7,8-dihydrone....1| ... D-erythro-7,8-dihydroneopterin triphosphate epimerase ... [...Shigella flexneri 2a str. 2457T] ref|NP_754732.1| ... D-erythro-7,8-dihydroneopterin triphosphate epi...merase ... [Escherichia coli CFT073] gb|AAP17710.1| ... D-erythro-7,8-dihydroneopterin triphos

  4. ORF Alignment: NC_004741 [GENIUS II[Archive

    Lifescience Database Archive (English)

    Full Text Available NC_004741 gi|30063729 >1nbuA 1 118 5 120 2e-19 ... ref|NP_708185.1| D-erythro-7,8-dihydrone...opterin triphosphate epimerase [Shigella ... flexneri 2a str. 301] gb|AAN43892.1| ... D-erythro-7,8-dihydrone....1| ... D-erythro-7,8-dihydroneopterin triphosphate epimerase ... [...Shigella flexneri 2a str. 2457T] ref|NP_754732.1| ... D-erythro-7,8-dihydroneopterin triphosphate epi...merase ... [Escherichia coli CFT073] gb|AAP17710.1| ... D-erythro-7,8-dihydroneopterin triphos

  5. Anti-enteric bacterial activity and phytochemical analysis of the seed kernel extract of Mangifera indica Linnaeus against Shigella dysenteriae (Shiga, corrig.) Castellani and Chalmers.

    Science.gov (United States)

    Rajan, S; Thirunalasundari, T; Jeeva, S

    2011-04-01

    To evaluate the phytochemical and anti-bacterial efficacy of the seed kernel extract of Mangifera indica (M. indica) against the enteropathogen, Shigella dysenteriae (S. dysenteriae), isolated from the diarrhoeal stool specimens. The preliminary phytochemical screening was performed by the standard methods as described by Harborne. Cold extraction method was employed to extract the bioactive compounds from mango seed kernel. Disc diffusion method was adopted to screen antibacterial activity. Minimum inhibitory concentration (MIC) was evaluated by agar dilution method. The crude extracts were partially purified by thin layer chromatography (TLC) and the fractions were analyzed by high performance thin layer chromatography (HPTLC) to identify the bioactive compounds. Phytochemical scrutiny of M. indica indicated the presence of phytochemical constituents such as alkaloids, gums, flavanoids, phenols, saponins, steroids, tannins and xanthoproteins. Antibacterial activity was observed in two crude extracts and various fractions viz. hexane, benzene, chloroform, methanol and water. MIC of methanol fraction was found to be (95±11.8) μg/mL. MIC of other fractions ranged from 130-380 μg/mL. The present study confirmed that each crude extracts and fractions of M. indica have significant antimicrobial activity against the isolated pathogen S. dysenteriae. The antibacterial activity may be due to the phytochemical constituents of the mango seed kernel. The phytochemical tannin could be the reason for its antibacterial activity. Copyright © 2011 Hainan Medical College. Published by Elsevier B.V. All rights reserved.

  6. Shigella IpaD has a dual role: signal transduction from the type III secretion system needle tip and intracellular secretion regulation.

    Science.gov (United States)

    Roehrich, A Dorothea; Guillossou, Enora; Blocker, Ariel J; Martinez-Argudo, Isabel

    2013-02-01

    Type III secretion systems (T3SSs) are protein injection devices essential for the interaction of many Gram-negative bacteria with eukaryotic cells. While Shigella assembles its T3SS when the environmental conditions are appropriate for invasion, secretion is only activated after physical contact with a host cell. First, the translocators are secreted to form a pore in the host cell membrane, followed by effectors which manipulate the host cell. Secretion activation is tightly controlled by conserved T3SS components: the needle tip proteins IpaD and IpaB, the needle itself and the intracellular gatekeeper protein MxiC. To further characterize the role of IpaD during activation, we combined random mutagenesis with a genetic screen to identify ipaD mutant strains unable to respond to host cell contact. Class II mutants have an overall defect in secretion induction. They map to IpaD's C-terminal helix and likely affect activation signal generation or transmission. The Class I mutant secretes translocators prematurely and is specifically defective in IpaD secretion upon activation. A phenotypically equivalent mutant was found in mxiC. We show that IpaD and MxiC act in the same intracellular pathway. In summary, we demonstrate that IpaD has a dual role and acts at two distinct locations during secretion activation. © 2013 Blackwell Publishing Ltd.

  7. Expression, purification, crystallization and preliminary X-ray diffraction analysis of the TonB-dependent haem outer membrane transporter ShuA from Shigella dysenteriae

    International Nuclear Information System (INIS)

    Brillet, Karl; Meksem, Ahmed; Thompson, Andrew; Cobessi, David

    2009-01-01

    ShuA from S. dysenteriae was crystallized in several crystallization conditions containing detergents. Adding heavy atoms during crystallization strongly improved the crystal quality and the resolution limits. Diffraction data were collected at an energy remote from the Pb M absorption edges. As part of efforts towards understanding the crystallization of membrane proteins and membrane transport across the outer membrane of Gram-negative bacteria, the TonB-dependent haem outer membrane transporter ShuA of Shigella dysenteriae bound to heavy atoms was crystallized in several crystallization conditions using detergents. The insertion of a His 6 tag into an extracellular loop of ShuA, instead of downstream of the Escherichia coli peptide signal, allowed efficient targeting to the outer membrane and the rapid preparation of crystallizable protein. Crystals diffracting X-rays beyond 3.5 Å resolution were obtained by co-crystallizing ShuA with useful heavy atoms for phasing (Eu, Tb, Pb) by the MAD method at the synchrotron, and the SAD or SIRAS method at the Cu wavelength. The authors collected X-ray diffraction data at 2.3 Å resolution using one crystal of ShuA-Pb, and at 3.2 Å resolution at an energy remote from the Pb M absorption edges for phasing on PROXIMA-1 at SOLEIL

  8. Comparison of two label-free global quantitation methods, APEX and 2D gel electrophoresis, applied to the Shigella dysenteriae proteome

    Directory of Open Access Journals (Sweden)

    Fleischmann Robert D

    2009-06-01

    Full Text Available Abstract The in vitro stationary phase proteome of the human pathogen Shigella dysenteriae serotype 1 (SD1 was quantitatively analyzed in Coomassie Blue G250 (CBB-stained 2D gels. More than four hundred and fifty proteins, of which 271 were associated with distinct gel spots, were identified. In parallel, we employed 2D-LC-MS/MS followed by the label-free computationally modified spectral counting method APEX for absolute protein expression measurements. Of the 4502 genome-predicted SD1 proteins, 1148 proteins were identified with a false positive discovery rate of 5% and quantitated using 2D-LC-MS/MS and APEX. The dynamic range of the APEX method was approximately one order of magnitude higher than that of CBB-stained spot intensity quantitation. A squared Pearson correlation analysis revealed a reasonably good correlation (R2 = 0.67 for protein quantities surveyed by both methods. The correlation was decreased for protein subsets with specific physicochemical properties, such as low Mr values and high hydropathy scores. Stoichiometric ratios of subunits of protein complexes characterized in E. coli were compared with APEX quantitative ratios of orthologous SD1 protein complexes. A high correlation was observed for subunits of soluble cellular protein complexes in several cases, demonstrating versatile applications of the APEX method in quantitative proteomics.

  9. Norovirus Real Time RT-PCR Detection Technology Transition to the Joint Biological Identification and Diagnosis System (JBAIDS)

    Science.gov (United States)

    2012-09-21

    virus and Southampton virus, and II (GII), which includes Bristol virus, Lordsdale virus, Toronto virus, Mexico virus, Hawaii virus and Snow Mountain...Shigella flexneriATCC12022 1 Negative Shigella sonnei ATCC25931 1 Negative Vibrio cholera (NAG) (Culture) 2 Negative Vibrio cholera (Ogawa...Culture) 1 Negative Vibrio cholera (Inaga) (Culture) 1 Negative Sapovivus (Known specimen extract) 2 Negative Rotavirus (Known specimen extract) 2

  10. Abstract Reference List: Reviews of Pertinent Literature in Shock. Volume I.

    Science.gov (United States)

    1981-05-18

    AND HEMORRHAGE. JP Dujardin, DN Stone, LT Paul, HP Pieper. Am J. Physiol. 238(6):H902-11908 (1980) .... ........ 25 60. EFFECT OF SHIGELLA FLENERI...Postgraduate Med. J. 50:55-59 (1974) ......... ...................... 34 85. CC]MPARATIVE TOXICITY OF NETILMICIN AND GENFAMICIN IN SQUIRREl. MONKEYS ...in earlier work from our lab. 60. Effect of Shigella flexneri Endotoxin on Ureagenesis and Liver Ultrastructure in Rabbits. M. Yoshino. Exp. iol. Path

  11. Infección por Campylobacter y Shigella como causa de Diarrea Aguda Infecciosa en niños menores de dos años en el Distrito de la Victoria, Lima-Perú

    OpenAIRE

    María Perales D; Máximo Camiña; Carmen Quiñones

    2002-01-01

    Objetivo: Determinar la frecuencia de Campylobacter y Shigella como agentes etiológicos en diarrea aguda acuosa en niños menores de dos años atendidos en 4 centros de salud del distrito de La Victoria (Lima, Perú) Materiales y métodos: en este estudio transversal analítico se realizaron coprocultivos bajo técnica microbiológica estándar a los niños menores de dos años con diarrea aguda acuosa atendidos en 4 centros de salud de La Victoria entre abril y octubre de 2001. Fueron excluidos aquell...

  12. Cloning of regions required for contact hemolysis and entry into LLC-MK2 cells from Shigella sonnei form I plasmid: virF is a positive regulator gene for these phenotypes.

    OpenAIRE

    Kato, J; Ito, K; Nakamura, A; Watanabe, H

    1989-01-01

    Two distinct regions required for both contact hemolysis and entry into LLC-MK2 cells were cloned into Escherichia coli from the Shigella sonnei form I plasmid, pSS120. The first region was cloned into an E. coli HB101 strain containing noninvasive Tn1 insertion mutants of the form I plasmid, and expression of ipa (invasion plasmid antigen) gene products was restored. The plasmid carrying the first region was then transformed into E. coli lacking the form I plasmid, and additional DNA fragmen...

  13. Prevalence of intestinal parasites, salmonella and shigella among apparently health food handlers of Addis Ababa University student's cafeteria, Addis Ababa, Ethiopia.

    Science.gov (United States)

    Aklilu, Addis; Kahase, Daniel; Dessalegn, Mekonnen; Tarekegn, Negatu; Gebremichael, Saba; Zenebe, Seyfe; Desta, Kassu; Mulugeta, Gebru; Mamuye, Yeshiwodim; Mama, Mohammedaman

    2015-01-24

    Food contamination may occur at any point during its journey through production, processing, distribution, and preparation. The risk of food getting contaminated depends largely on the health status of the food handlers, their personal hygiene, knowledge and practice of food hygiene. Food borne diseases are a public health problem in developed and developing countries like Ethiopia. A cross sectional study was conducted among food handlers in Addis Ababa student's cafeteria from January to May 2013. Structured questionnaire was used to collect socio demographic data and associated risk factors. Stool specimens were examined for bacteria and intestinal parasites following standard procedures. Biochemical tests were done to identify the species of bacterial isolates. Sensitivity testing was done using Kirby- Baur disk diffusion method. A total of 172 food handlers were enrolled in the study. The majority of study participants were females 134 (77.9%). About 78 (45.3%) of food handlers were found to be positive for different intestinal parasites with the most abundant parasite of Entameoba histolytica/dispar 68 (70.8%) followed by Giardia lamblia 18 (18.8%), Taenia species 5 (5.2%), Ascaris lumbricoides 2 (2.1%), hookworm 2 (2.1%) and Trichuris trichiura 1 (1.1%). Stool cultures revealed 3.5% of Salmonella isolates (Sero-grouping on Salmonella isolate was not done), while Shigella species was not isolated from any of the stool samples obtained from Food handlers. All isolates of Salmonella were sensitive to ciprofloxacin, amikacin and gentamicin but resistant to ampicillin, clindamycin, and erythromycin. The present study revealed a high prevalence of intestinal parasite in asymptomatic (apparently health) food handlers. Such infected food handlers can contaminate food, drinks and could serve as source of infection to consumers via food chain.

  14. Characterization of a Large Antibiotic Resistance Plasmid Found in Enteropathogenic Escherichia coli Strain B171 and Its Relatedness to Plasmids of Diverse E. coli and Shigella Strains.

    Science.gov (United States)

    Hazen, Tracy H; Michalski, Jane; Nagaraj, Sushma; Okeke, Iruka N; Rasko, David A

    2017-09-01

    Enteropathogenic Escherichia coli (EPEC) is a leading cause of severe infantile diarrhea in developing countries. Previous research has focused on the diversity of the EPEC virulence plasmid, whereas less is known regarding the genetic content and distribution of antibiotic resistance plasmids carried by EPEC. A previous study demonstrated that in addition to the virulence plasmid, reference EPEC strain B171 harbors a second, larger plasmid that confers antibiotic resistance. To further understand the genetic diversity and dissemination of antibiotic resistance plasmids among EPEC strains, we describe the complete sequence of an antibiotic resistance plasmid from EPEC strain B171. The resistance plasmid, pB171_90, has a completed sequence length of 90,229 bp, a GC content of 54.55%, and carries protein-encoding genes involved in conjugative transfer, resistance to tetracycline ( tetA ), sulfonamides ( sulI ), and mercury, as well as several virulence-associated genes, including the transcriptional regulator hha and the putative calcium sequestration inhibitor ( csi ). In silico detection of the pB171_90 genes among 4,798 publicly available E. coli genome assemblies indicates that the unique genes of pB171_90 ( csi and traI ) are primarily restricted to genomes identified as EPEC or enterotoxigenic E. coli However, conserved regions of the pB171_90 plasmid containing genes involved in replication, stability, and antibiotic resistance were identified among diverse E. coli pathotypes. Interestingly, pB171_90 also exhibited significant similarity with a sequenced plasmid from Shigella dysenteriae type I. Our findings demonstrate the mosaic nature of EPEC antibiotic resistance plasmids and highlight the need for additional sequence-based characterization of antibiotic resistance plasmids harbored by pathogenic E. coli . Copyright © 2017 American Society for Microbiology.

  15. Caracterización proteómica de vesículas de membrana externa extraídas de Shigella sonnei

    Directory of Open Access Journals (Sweden)

    María de los A Padrón-Collaz

    2017-12-01

    Full Text Available Las vacunas compuestas por vesículas de membrana externa (VMEs previenen de manera exitosa la enfermedad meningocócica del serogrupo B. Esta plataforma tecnológica de obtención puede ser aplicada para otros patógenos bacterianos Gram negativos. Una vacuna de VMEs desarrollada contra Shigella sonnei fue obtenida a través de una extracción de componentes celulares y su caracterización por electroforesis en geles de poliacrilamida unidimensional (1D. Se estudiaron las mejores condiciones de solubilización de las muestras, separación electroforética e identificación a través de espectrometría de masas acoplada a cromatografía de alta presión después del corte de las bandas y su tratamiento enzimático con tripsina. En esta etapa se identificaron un total de 57 proteínas en 23 bandas (2,5 proteínas por banda escindida, 47 de las proteínas no repetidas. Las proteínas inmunogénicas presentes en VMEs de S. sonnei fueron cuantificadas en cuanto a masa molecular por 1D-Western blotting en membranas de nitrocelulosa con anticuerpos obtenidos a partir de ratones inmunizados con las VMEs. Como que las bandas electroforéticas 1D contenían más de una proteína, se estudiaron las mejores condiciones de separación por el método de electroforesis bidimensional (2D para el establecimiento del mapa proteico; tal que el incremento del tamaño de las tiras, el tiempo de focalización y la aplicación catódica garantizaron la mayor resolución.

  16. One Gene and Two Proteins: a Leaderless mRNA Supports the Translation of a Shorter Form of the Shigella VirF Regulator

    Directory of Open Access Journals (Sweden)

    Maria Letizia Di Martino

    2016-11-01

    Full Text Available VirF, an AraC-like activator, is required to trigger a regulatory cascade that initiates the invasive program of Shigella spp., the etiological agents of bacillary dysentery in humans. VirF expression is activated upon entry into the host and depends on many environmental signals. Here, we show that the virF mRNA is translated into two proteins, the major form, VirF30 (30 kDa, and the shorter VirF21 (21 kDa, lacking the N-terminal segment. By site-specific mutagenesis and toeprint analysis, we identified the translation start sites of VirF30 and VirF21 and showed that the two different forms of VirF arise from differential translation. Interestingly, in vitro and in vivo translation experiments showed that VirF21 is also translated from a leaderless mRNA (llmRNA whose 5′ end is at position +309/+310, only 1 or 2 nucleotides upstream of the ATG84 start codon of VirF21. The llmRNA is transcribed from a gene-internal promoter, which we identified here. Functional analysis revealed that while VirF30 is responsible for activation of the virulence system, VirF21 negatively autoregulates virF expression itself. Since VirF21 modulates the intracellular VirF levels, this suggests that transcription of the llmRNA might occur when the onset of the virulence program is not required. We speculate that environmental cues, like stress conditions, may promote changes in virF mRNA transcription and preferential translation of llmRNA.

  17. UV irradiation of Shigella Dysenteriae induced the transformation and excision of a presumed integrated lysogenic prophage Shd-4L10 into a lytic phase

    International Nuclear Information System (INIS)

    Rodrigues, F. K.; Addy, B.; Armah, G.; Fobil, J.; Steiner-Asiedu, M.; Efavi, J.

    2012-01-01

    Repeated exposures of Shigella dysenteriae strain A to ultra-violet radiation (253.7 nm) with intervening outgrowth of survivors gave rise to clear bacteriophage plaques. Isolation, propagation and partial purification of the new Shd-4LI0 phages showed that they are similar in morphology to the Myxobacteriaphage Mx-4 described earlier. The new phages retained the general characteristics of S. dystenteriae phageShd-4L3, including serological properties and phage typing. It is suggested that ultra-violet irradiation may have played a role in the transformation and excision of the presumed lysogen of S. dysenteriaestrain A into a lytic phase. PhageShd-4LI0 was subsequently partially characterized. It has a density of 1.61, a DNA: protein ratio of 0.42 and thus a cryptogram of D/2:54.3/32.5:X/X: B/O. The phage was further characterised by fractionation of its protein using SDS-polyacrilamide gel electrophoresis. DNA extracted from phages was hydrolysed with restriction endonuclease R., EcoR1. The restriction fragments were catalogued and their apparent molecular weights calculated from electrophoresis gels calibrated with fragments from DNA of coliphageλ λ. From the total fragments obtained with nuclease R., EcoR1, the apparent minimum molecular weight of phage Shd-4LI0DNA was found to be 54.3 x 10 6 Daltons. The molecular weight of the phage DNA was also calculated from measurements of contour length of purified DNA samples, using the formula MW = 1.97 x 10 10 1/(magnification), where 1 is the measured length of DNA in centimetres). The very close relatedness with phage Shd-4L3 was confirmed by these techniques. (au)

  18. A Shigella sonnei outbreak traced to imported basil--the importance of good typing tools and produce traceability systems, Norway, 2011.

    Science.gov (United States)

    Guzman-Herrador, B R; Nilsen, E; Cudjoe, K S; Jensvoll, L; Kvamme, J M; Lindegård Aanstad, A; Lindstedt, B A; Nygård, K; Severinsen, G; Werner-Johansen, Ø; Wester, A L; Wiklund, M; Vold, L

    2013-12-05

    On 9 October 2011, the University Hospital of North Norway alerted the Norwegian Institute of Public Health (NIPH) about an increase in Shigella sonnei infections in Tromsø. The isolates had an identical ‘multilocus variable-number tandem repeat analysis’ (MLVA) profile. Most cases had consumed food provided by delicatessen X. On 14 October, new S. sonnei cases with the same MLVA-profile were reported from Sarpsborg, south-eastern Norway. An outbreak investigation was started to identify the source and prevent further cases. All laboratory-confirmed cases from both clusters were attempted to be interviewed. In addition, a cohort study was performed among the attendees of a banquet in Tromsø where food from delicatessen X had been served and where some people had reported being ill. A trace-back investigation was initiated. In total, 46 cases were confirmed (Tromsø= 42; Sarpsborg= 4). Having eaten basil pesto sauce or fish soup at the banquet in Tromsø were independent risk factors for disease. Basil pesto was the only common food item that had been consumed by confirmed cases occurring in Tromsø and Sarpsborg. The basil had been imported and delivered to both municipalities by the same supplier. No basil from the specific batch was left on the Norwegian market when it was identified as the likely source. As a result of the multidisciplinary investigation, which helped to identify the source, the Norwegian Food Safety Authority, together with NIPH, planned to develop recommendations for food providers on how to handle fresh plant produce prior to consumption.

  19. In vitro Synergy and Time-kill Assessment of Interaction between ...

    African Journals Online (AJOL)

    The antibacterial combinations resulted in drastic decrease in MIC with increased antibacterial activity that indicated synergistic interaction against all the bacteria except Acinetobacter calcaoceuticus UP, Enterobacter cloacae ATCC 13047 and Shigella flexneri KZN. Fractional inhibitory concentration index (FICI) showed ...

  20. Efficient regeneration of NADPH in a 3-enzyme cascade reaction by in situ generation of glucose 6-phosphate from glucose and pyrophosphate

    NARCIS (Netherlands)

    Hartog, A.F.; van Herk, T.; Wever, R.

    2011-01-01

    We report here a promising method to regenerate NADPH (nicotinamide adenine dinucleotide phosphate) using the intermediate formation of glucose 6-phosphate (G6P) from glucose and pyrophosphate (PPi) catalyzed by the acid phosphatase from Shigella flexneri (PhoN-Sf). The G6P formed is used in turn by

  1. Radio-resistance of some bacterial pathogens in soft-shell clams (Mya arenaria) and mussels (Mytilus edulis)

    International Nuclear Information System (INIS)

    Licciardello, J.J.; D'Entremont, D.L.; Lundstrom, R.C.

    1989-01-01

    Gamma-irradiation decimal reduction doses were determined for E. coli, Salmonella typhimurium, Shigella flexneri, Strept. faecalis, Staph, aureus, and the Total Plate Count in a soft-shell clam or mussel substrate. Factors to be considered for designing and irradiation bacterial-decontamination process for shellfish are discussed

  2. Intervention sensu Wilson: The only valid approach to microbiological safety of food

    NARCIS (Netherlands)

    Mossel, D.A.A.; Kayser, A.

    1984-01-01

    Between December 25th 1983 and January 7th 1984 59 cases of dysentery bacteriologically proven to be caused by Shigella flexneri 2 occurred in the Netherlands. For a further 34 cases of gastroenteritis, strong epidemiological evidence was present to allow the diagnosis of shigellosis. In

  3. Sensitivity and specificity of leukocyte count in feces as a predictor of stool culture positivity for S amonella or Shigella Sensibilidad y especificidad del recuento de leucocitos en las materias fecales para predecir la presencia de Salmonella o Shigella en pacientes con enfermedad diarreica aguda

    Directory of Open Access Journals (Sweden)

    John Jairo Zuleta Tobón

    2008-01-01

    Full Text Available

    In most studies of fecal leukocyte counts as predictors of the result of stool cultures the sensitivity and specificity were not determined.

    Objective: to evaluate fecal leukocyte counts as a predictor of the presence of Salmonella and Shigella.

    Design: a descriptive, cross section study was carried out in 905 stool cultures at a university hospital in Medellín, Colombia. Results for Salmonella and Shigella were taken as the gold standard to evaluate the sensitivity and specificity of fecal leukocyte counts.

    Results: sensitivity and specificity, according to the level of the count, were, respectively: 1-5 leukocytes: 89.2% and 57.1%; 6-10 leukocytes: 86.2% and 52.8%;11-20 leukocytes: 77.7% and 62.7%; 21-30 leukocytes: 63.9% and 76.3%; 31-50 leukocytes: 45.2% and 85.5%; more than 50 leukocytes: 28.3% and 90.9%. The area under the curve was 0.7699 (CI 95%: 0.7275-0.8123.

    Conclusions: Eukaryotic translation initiation factor 5A of wheat: Identification ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-05-18

    . The available literature indi- cated that the expression of eIF5A was temporal and spatial difference and suppressing eIF5A activation causes pleiotropic effects. Transcript analysis reveals that two tobacco eIF5A genes ...

  4. A Phase 2a Randomized Study to Evaluate the Safety and Immunogenicity of the 1790GAHB Generalized Modules for Membrane Antigen Vaccine against Shigella sonnei Administered Intramuscularly to Adults from a Shigellosis-Endemic Country

    Directory of Open Access Journals (Sweden)

    Christina W. Obiero

    2017-12-01

    Full Text Available Shigellosis is a mild-to-severe diarrheal infection, caused by the genus Shigella, and is responsible for significant morbidity and mortality worldwide. We evaluated the safety and immunogenicity of an investigational Shigella sonnei vaccine (1790GAHB based on generalized modules for membrane antigens (GMMA in Kenya, a Shigella-endemic country. This phase 2a, observer-blind, controlled randomized study (NCT02676895 enrolled 74 healthy adults aged 18–45 years, of whom 72 were vaccinated. Participants received, in a 1:1:1 ratio, two vaccinations with the 1790GAHB vaccine at doses of either 1.5/25 μg of O antigen (OAg/protein (group 1.5/25 μg or 5.9/100 μg (group 5.9/100 μg at day (D 1 and D29, or vaccination with a quadrivalent meningococcal vaccine at D1 and tetanus, diphtheria, and acellular pertussis vaccine at D29 (control group. Solicited and unsolicited adverse events (AEs, serious AEs (SAEs, and AEs of special interest (neutropenia and reactive arthritis were collected. Anti-S. sonnei lipopolysaccharide (LPS serum immunoglobulin G (IgG geometric mean concentrations (GMC were evaluated at D1, D29, and D57 and compared to anti-S. sonnei LPS antibody levels in convalescent patients naturally exposed to S. sonnei. The percentages of participants with seroresponse were also calculated. The most frequently reported solicited local and systemic AEs across all groups were pain and headache, respectively. Only one case of severe systemic reaction was reported (severe headache after first vaccination in group 5.9/100 μg. Seven and three episodes of neutropenia, assessed as probably or possibly related to vaccination respectively, were reported in the investigational and control groups, respectively. No other SAEs were reported. Despite very high baseline anti-S. sonnei LPS serum IgG levels, the 1790GAHB vaccine induced robust antibody responses. At D29, GMC increased 2.10- and 4.43-fold from baseline in groups 1.5/25 and 5.9/100

  5. Eukaryotic translation initiation factor 5A (eIF5A) is essential for HIF-1α activation in hypoxia

    Energy Technology Data Exchange (ETDEWEB)

    Tariq, Mohammad [Chemical Genetics Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Graduate School of Science and Engineering, Saitama University, 645 Shimo-Okubo, Sakura-ku, Saitama 338-8570 (Japan); Ito, Akihiro, E-mail: akihiro-i@riken.jp [Chemical Genetics Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Chemical Genomics Research Group, RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Japan Agency for Medical Research and Development, AMED-CREST, 1-7-1 Otemachi, Chiyoda-ku, Tokyo, 100-0004 (Japan); Ishfaq, Muhammad; Bradshaw, Elliot [Chemical Genetics Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Graduate School of Science and Engineering, Saitama University, 645 Shimo-Okubo, Sakura-ku, Saitama 338-8570 (Japan); Yoshida, Minoru [Chemical Genetics Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Chemical Genomics Research Group, RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Graduate School of Science and Engineering, Saitama University, 645 Shimo-Okubo, Sakura-ku, Saitama 338-8570 (Japan); Japan Agency for Medical Research and Development, AMED-CREST, 1-7-1 Otemachi, Chiyoda-ku, Tokyo, 100-0004 (Japan)

    2016-02-05

    The eukaryotic initiation factor 5A (eIF5A) is an essential protein involved in translation elongation and cell proliferation. eIF5A undergoes several post-translational modifications including hypusination and acetylation. Hypusination is indispensable for the function of eIF5A. On the other hand, the precise function of acetylation remains unknown, but it may render the protein inactive since hypusination blocks acetylation. Here, we report that acetylation of eIF5A increases under hypoxia. During extended hypoxic periods an increase in the level of eIF5A acetylation correlated with a decrease in HIF-1α, suggesting involvement of eIF5A activity in HIF-1α expression under hypoxia. Indeed, suppression of eIF5A by siRNA oligo-mediated knockdown or treatment with GC7, a deoxyhypusine synthase inhibitor, led to significant reduction of HIF-1α activity. Furthermore, knockdown of eIF5A or GC7 treatment reduced tumor spheroid formation with a concomitant decrease in HIF-1α expression. Our results suggest that functional, hypusinated eIF5A is necessary for HIF-1α expression during hypoxia and that eIF5A is an attractive target for cancer therapy. - Highlights: • Hypoxia induces acetylation of eIF5A. • Active eIF5A is necessary for HIF-1α activation in hypoxia. • Active eIF5A is important for tumor spheroid growth.

  6. Eukaryotic translation initiation factor 5A (eIF5A) is essential for HIF-1α activation in hypoxia

    International Nuclear Information System (INIS)

    Tariq, Mohammad; Ito, Akihiro; Ishfaq, Muhammad; Bradshaw, Elliot; Yoshida, Minoru

    2016-01-01

    The eukaryotic initiation factor 5A (eIF5A) is an essential protein involved in translation elongation and cell proliferation. eIF5A undergoes several post-translational modifications including hypusination and acetylation. Hypusination is indispensable for the function of eIF5A. On the other hand, the precise function of acetylation remains unknown, but it may render the protein inactive since hypusination blocks acetylation. Here, we report that acetylation of eIF5A increases under hypoxia. During extended hypoxic periods an increase in the level of eIF5A acetylation correlated with a decrease in HIF-1α, suggesting involvement of eIF5A activity in HIF-1α expression under hypoxia. Indeed, suppression of eIF5A by siRNA oligo-mediated knockdown or treatment with GC7, a deoxyhypusine synthase inhibitor, led to significant reduction of HIF-1α activity. Furthermore, knockdown of eIF5A or GC7 treatment reduced tumor spheroid formation with a concomitant decrease in HIF-1α expression. Our results suggest that functional, hypusinated eIF5A is necessary for HIF-1α expression during hypoxia and that eIF5A is an attractive target for cancer therapy. - Highlights: • Hypoxia induces acetylation of eIF5A. • Active eIF5A is necessary for HIF-1α activation in hypoxia. • Active eIF5A is important for tumor spheroid growth.

  7. EFSA BIOHAZ Panel (EFSA Panel on Biological Hazards), 2014. Scientific Opinion on the risk posed by pathogens in food of non-animal origin. Part 2 (Salmonella Yersinia, Shigella and Norovirus in bulb and stem vegetables, and carrots)

    DEFF Research Database (Denmark)

    Hald, Tine; Baggesen, Dorte Lau

    , Shigella and Norovirus were considered in the context of the whole food chain. Available estimates of their occurrence in these vegetables were evaluated together with mitigation options relating to prevention of contamination and the relevance of microbiological criteria. Emphasis is given to vegetable...... of food safety management systems including Good Agricultural Practices (GAP), Good Hygiene Practices (GHP) and Good Manufacturing Practices (GMP) should be the primary objectives of producers of bulb and stem vegetables as well as carrots. Considering the limited evidence for both the occurrence......Bulb and stem vegetables as well as carrots may be minimally processed to obtain ready-to-eat products, and these steps include selection, washing, cleaning, cutting, packaging and storage. Risk factors for the contamination of bulb and stem vegetables as well as carrots with Salmonella, Yersinia...

  8. Eukaryotic translation initiation factor 5A of wheat: Identification ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-05-18

    May 18, 2009 ... Alignment of the amino acid sequence of eIF5A from wheat, tomato, potato, rice, Arabidopsis, maize, human, mouse, rabbit and C. elegan. The protein sequence shown in the diagrams are listed in the GenBank database under the following accession number: AteIF5A-1 (AAD39281), CeeIF5A-1 (P34563), ...

  9. Genomics of Escherichia and Shigella

    Science.gov (United States)

    Perna, Nicole T.

    The laboratory workhorse Escherichia coli K-12 is among the most intensively studied living organisms on earth, and this single strain serves as the model system behind much of our understanding of prokaryotic molecular biology. Dense genome sequencing and recent insightful comparative analyses are making the species E. coli, as a whole, an emerging system for studying prokaryotic population genetics and the relationship between system-scale, or genome-scale, molecular evolution and complex traits like host range and pathogenic potential. Genomic perspective has revealed a coherent but dynamic species united by intraspecific gene flow via homologous lateral or horizontal transfer and differentiated by content flux mediated by acquisition of DNA segments from interspecies transfers.

  10. HSV neutralization by the microbicidal candidate C5A

    NARCIS (Netherlands)

    de Witte, L.; Bobardt, M.D.; Chatterji, U.; van Loenen, F.B.; Verjans, G.M.G.M.; Geijtenbeek, T.B.H.; Gallay, P.A.

    2011-01-01

    Genital herpes is a major risk factor in acquiring human immunodeficiency virus type-1 (HIV-1) infection and is caused by both Herpes Simplex virus type 1 (HSV-1) and HSV-2. The amphipathic peptide C5A, derived from the non-structural hepatitis C virus (HCV) protein 5A, was shown to prevent HIV-1

  11. HSV neutralization by the microbicidal candidate C5A

    NARCIS (Netherlands)

    L. de Witte (Lot); M.D. Bobardt (Michael); U. Chatterji (Udayan); F.B. van Loenen (Freek); G.M.G.M. Verjans (George); T.B.H. Geijtenbeek (Teunis); P.A. Gallay (Philippe)

    2011-01-01

    textabstractGenital herpes is a major risk factor in acquiring human immunodeficiency virus type-1 (HIV-1) infection and is caused by both Herpes Simplex virus type 1 (HSV-1) and HSV-2. The amphipathic peptide C5A, derived from the non-structural hepatitis C virus (HCV) protein 5A, was shown to

  12. Wnt5a regulates midbrain dopaminergic axon growth and guidance.

    Directory of Open Access Journals (Sweden)

    Brette D Blakely

    2011-03-01

    Full Text Available During development, precise temporal and spatial gradients are responsible for guiding axons to their appropriate targets. Within the developing ventral midbrain (VM the cues that guide dopaminergic (DA axons to their forebrain targets remain to be fully elucidated. Wnts are morphogens that have been identified as axon guidance molecules. Several Wnts are expressed in the VM where they regulate the birth of DA neurons. Here, we describe that a precise temporo-spatial expression of Wnt5a accompanies the development of nigrostriatal projections by VM DA neurons. In mice at E11.5, Wnt5a is expressed in the VM where it was found to promote DA neurite and axonal growth in VM primary cultures. By E14.5, when DA axons are approaching their striatal target, Wnt5a causes DA neurite retraction in primary cultures. Co-culture of VM explants with Wnt5a-overexpressing cell aggregates revealed that Wnt5a is capable of repelling DA neurites. Antagonism experiments revealed that the effects of Wnt5a are mediated by the Frizzled receptors and by the small GTPase, Rac1 (a component of the non-canonical Wnt planar cell polarity pathway. Moreover, the effects were specific as they could be blocked by Wnt5a antibody, sFRPs and RYK-Fc. The importance of Wnt5a in DA axon morphogenesis was further verified in Wnt5a-/- mice, where fasciculation of the medial forebrain bundle (MFB as well as the density of DA neurites in the MFB and striatal terminals were disrupted. Thus, our results identify a novel role of Wnt5a in DA axon growth and guidance.

  13. The extant World War 1 dysentery bacillus NCTC1: a genomic analysis.

    Science.gov (United States)

    Baker, Kate S; Mather, Alison E; McGregor, Hannah; Coupland, Paul; Langridge, Gemma C; Day, Martin; Deheer-Graham, Ana; Parkhill, Julian; Russell, Julie E; Thomson, Nicholas R

    2014-11-08

    Shigellosis (previously bacillary dysentery) was the primary diarrhoeal disease of World War 1, but outbreaks still occur in military operations, and shigellosis causes hundreds of thousands of deaths per year in developing nations. We aimed to generate a high-quality reference genome of the historical Shigella flexneri isolate NCTC1 and to examine the isolate for resistance to antimicrobials. In this genomic analysis, we sequenced the oldest extant Shigella flexneri serotype 2a isolate using single-molecule real-time (SMRT) sequencing technology. Isolated from a soldier with dysentery from the British forces fighting on the Western Front in World War 1, this bacterium, NCTC1, was the first isolate accessioned into the National Collection of Type Cultures. We created a reference sequence for NCTC1, investigated the isolate for antimicrobial resistance, and undertook comparative genetics with S flexneri reference strains isolated during the 100 years since World War 1. We discovered that NCTC1 belonged to a 2a lineage of S flexneri, with which it shares common characteristics and a large core genome. NCTC1 was resistant to penicillin and erythromycin, and contained a complement of chromosomal antimicrobial resistance genes similar to that of more recent isolates. Genomic islands gained in the S flexneri 2a lineage over time were predominately associated with additional antimicrobial resistances, virulence, and serotype conversion. This S flexneri 2a lineage is a well adapted pathogen that has continued to respond to selective pressures. We have created a valuable historical benchmark for shigellae in the form of a high-quality reference sequence for a publicly available isolate. The Wellcome Trust. Copyright © 2014 Baker et al. Open Access article distributed under the terms of CC BY. Published by Elsevier Ltd. All rights reserved.

  14. Analysis on the Interaction Domain of VirG and Apyrase by Pull-Down Assay

    Directory of Open Access Journals (Sweden)

    Yu Wang

    2014-11-01

    Full Text Available VirG is outer membrane protein of Shigella and affects the spread of Shigella. Recently it has been reported that apyrase influences the location of VirG, although the underlying mechanism remains poorly understood. The site of interaction between apyrase and VirG is the focus of our research. First we constructed recombinant plasmid pHIS-phoN2 and pS-(v1–1102, v53–758, v759–1102, v53–319, v320–507, v507–758 by denaturation-renaturation, the phoN2:kan mutant of Shigella flexneri 5a M90T by a modified version of the lambda red recombination protocol originally described by Datsenko and Wanner and the complemented strain M90TΔphoN2/pET24a(PhisphoN2. Second, the recombinant plasmid pHIS-phoN2 and the pS-(v1–1102, v53–758, v759–1102, v53–319, v320–507, v507–758 were transformed into E. coli BL21 (DE3 and induced to express the fusion proteins. Third, the fusion proteins were purified and the interaction of VirG and apyrase was identified by pull-down. Fourth, VirG was divided and the interaction site of apyrase and VirG was determined. Finally, how apyrase affects the function of VirG was analyzed by immunofluorescence. Accordingly, the results provided the data supporting the fact that apyrase combines with the α-domain of VirG to influence the function of VirG.

  15. Next Generation Qualification: Kinemetrics STS-5A Seismometer Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Merchant, Bion John [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Slad, George William [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-10-01

    Sandia National Laboratories has tested and evaluated two seismometers, the STS-5A, manufactured by Kinemetrics. These seismometers measure three axes of broadband ground velocity using a UVW configuration with feedback control in a mechanically levelled borehole package. The purpose of the seismometer evaluation was to determine a measured sensitivity, response, self-noise, dynamic range, and self-calibration ability. The Kinemetrics STS-5A seismometers are being evaluated for the U.S. Air Force as part of their Next Generation Qualification effort.

  16. Hot-spot KIF5A mutations cause familial ALS.

    Science.gov (United States)

    Brenner, David; Yilmaz, Rüstem; Müller, Kathrin; Grehl, Torsten; Petri, Susanne; Meyer, Thomas; Grosskreutz, Julian; Weydt, Patrick; Ruf, Wolfgang; Neuwirth, Christoph; Weber, Markus; Pinto, Susana; Claeys, Kristl G; Schrank, Berthold; Jordan, Berit; Knehr, Antje; Günther, Kornelia; Hübers, Annemarie; Zeller, Daniel; Kubisch, Christian; Jablonka, Sibylle; Sendtner, Michael; Klopstock, Thomas; de Carvalho, Mamede; Sperfeld, Anne; Borck, Guntram; Volk, Alexander E; Dorst, Johannes; Weis, Joachim; Otto, Markus; Schuster, Joachim; Del Tredici, Kelly; Braak, Heiko; Danzer, Karin M; Freischmidt, Axel; Meitinger, Thomas; Strom, Tim M; Ludolph, Albert C; Andersen, Peter M; Weishaupt, Jochen H

    2018-01-12

    Heterozygous missense mutations in the N-terminal motor or coiled-coil domains of the kinesin family member 5A (KIF5A) gene cause monogenic spastic paraplegia (HSP10) and Charcot-Marie-Tooth disease type 2 (CMT2). Moreover, heterozygous de novo frame-shift mutations in the C-terminal domain of KIF5A are associated with neonatal intractable myoclonus, a neurodevelopmental syndrome. These findings, together with the observation that many of the disease genes associated with amyotrophic lateral sclerosis disrupt cytoskeletal function and intracellular transport, led us to hypothesize that mutations in KIF5A are also a cause of amyotrophic lateral sclerosis. Using whole exome sequencing followed by rare variant analysis of 426 patients with familial amyotrophic lateral sclerosis and 6137 control subjects, we detected an enrichment of KIF5A splice-site mutations in amyotrophic lateral sclerosis (2/426 compared to 0/6137 in controls; P = 4.2 × 10-3), both located in a hot-spot in the C-terminus of the protein and predicted to affect splicing exon 27. We additionally show co-segregation with amyotrophic lateral sclerosis of two canonical splice-site mutations in two families. Investigation of lymphoblast cell lines from patients with KIF5A splice-site mutations revealed the loss of mutant RNA expression and suggested haploinsufficiency as the most probable underlying molecular mechanism. Furthermore, mRNA sequencing of a rare non-synonymous missense mutation (predicting p.Arg1007Gly) located in the C-terminus of the protein shortly upstream of the splice donor of exon 27 revealed defective KIF5A pre-mRNA splicing in respective patient-derived cell lines owing to abrogation of the donor site. Finally, the non-synonymous single nucleotide variant rs113247976 (minor allele frequency = 1.00% in controls, n = 6137), also located in the C-terminal region [p.(Pro986Leu) in exon 26], was significantly enriched in familial amyotrophic lateral sclerosis patients (minor allele

  17. Hot-spot KIF5A mutations cause familial ALS

    Science.gov (United States)

    Yilmaz, Rüstem; Müller, Kathrin; Grehl, Torsten; Petri, Susanne; Meyer, Thomas; Grosskreutz, Julian; Weydt, Patrick; Ruf, Wolfgang; Neuwirth, Christoph; Weber, Markus; Pinto, Susana; Claeys, Kristl G; Schrank, Berthold; Jordan, Berit; Knehr, Antje; Günther, Kornelia; Hübers, Annemarie; Zeller, Daniel; Kubisch, Christian; Jablonka, Sibylle; Klopstock, Thomas; de Carvalho, Mamede; Sperfeld, Anne; Borck, Guntram; Volk, Alexander E; Dorst, Johannes; Weis, Joachim; Otto, Markus; Schuster, Joachim; Del Tredici, Kelly; Braak, Heiko; Danzer, Karin M; Freischmidt, Axel; Meitinger, Thomas; Strom, Tim M; Ludolph, Albert C; Andersen, Peter M; Weishaupt, Jochen H; Weyen, Ute; Hermann, Andreas; Hagenacker, Tim; Koch, Jan Christoph; Lingor, Paul; Göricke, Bettina; Zierz, Stephan; Baum, Petra; Wolf, Joachim; Winkler, Andrea; Young, Peter; Bogdahn, Ulrich; Prudlo, Johannes; Kassubek., Jan

    2018-01-01

    Abstract Heterozygous missense mutations in the N-terminal motor or coiled-coil domains of the kinesin family member 5A (KIF5A) gene cause monogenic spastic paraplegia (HSP10) and Charcot-Marie-Tooth disease type 2 (CMT2). Moreover, heterozygous de novo frame-shift mutations in the C-terminal domain of KIF5A are associated with neonatal intractable myoclonus, a neurodevelopmental syndrome. These findings, together with the observation that many of the disease genes associated with amyotrophic lateral sclerosis disrupt cytoskeletal function and intracellular transport, led us to hypothesize that mutations in KIF5A are also a cause of amyotrophic lateral sclerosis. Using whole exome sequencing followed by rare variant analysis of 426 patients with familial amyotrophic lateral sclerosis and 6137 control subjects, we detected an enrichment of KIF5A splice-site mutations in amyotrophic lateral sclerosis (2/426 compared to 0/6137 in controls; P = 4.2 × 10−3), both located in a hot-spot in the C-terminus of the protein and predicted to affect splicing exon 27. We additionally show co-segregation with amyotrophic lateral sclerosis of two canonical splice-site mutations in two families. Investigation of lymphoblast cell lines from patients with KIF5A splice-site mutations revealed the loss of mutant RNA expression and suggested haploinsufficiency as the most probable underlying molecular mechanism. Furthermore, mRNA sequencing of a rare non-synonymous missense mutation (predicting p.Arg1007Gly) located in the C-terminus of the protein shortly upstream of the splice donor of exon 27 revealed defective KIF5A pre-mRNA splicing in respective patient-derived cell lines owing to abrogation of the donor site. Finally, the non-synonymous single nucleotide variant rs113247976 (minor allele frequency = 1.00% in controls, n = 6137), also located in the C-terminal region [p.(Pro986Leu) in exon 26], was significantly enriched in familial amyotrophic lateral sclerosis patients (minor

  18. Characterization of SLCO5A1/OATP5A1, a solute carrier transport protein with non-classical function.

    Directory of Open Access Journals (Sweden)

    Katrin Sebastian

    Full Text Available Organic anion transporting polypeptides (OATP/SLCO have been identified to mediate the uptake of a broad range of mainly amphipathic molecules. Human OATP5A1 was found to be expressed in the epithelium of many cancerous and non-cancerous tissues throughout the body but protein characterization and functional analysis have not yet been performed. This study focused on the biochemical characterization of OATP5A1 using Xenopus laevis oocytes and Flp-In T-REx-HeLa cells providing evidence regarding a possible OATP5A1 function. SLCO5A1 is highly expressed in mature dendritic cells compared to immature dendritic cells (∼6.5-fold and SLCO5A1 expression correlates with the differentiation status of primary blood cells. A core- and complex- N-glycosylated polypeptide monomer of ∼105 kDa and ∼130 kDa could be localized in intracellular membranes and on the plasma membrane, respectively. Inducible expression of SLCO5A1 in HeLa cells led to an inhibitory effect of ∼20% after 96 h on cell proliferation. Gene expression profiling with these cells identified immunologically relevant genes (e.g. CCL20 and genes implicated in developmental processes (e.g. TGM2. A single nucleotide polymorphism leading to the exchange of amino acid 33 (L→F revealed no differences regarding protein expression and function. In conclusion, we provide evidence that OATP5A1 might be a non-classical OATP family member which is involved in biological processes that require the reorganization of the cell shape, such as differentiation and migration.

  19. Recombinant production of the human complement factor 5a in ...

    African Journals Online (AJOL)

    African Journal of Biotechnology ... Using C5a as an example, we showed that strain engineering in combination with specific cultivation conditions improve the production of difficult-to-express proteins in appropriate amounts and in a functional conformation facilitating the commercial manufacturing under good ...