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Background In Southeast-Asia, where many conditions associated with dissemination of ESBL-producing Enterobacterales (ESBL-E) in the community are met, data from the community are scarce but show high ESBL-E carriage prevalence. Maternal ESBL-E colonization is considered a risk factor for neonatal colonization, which is the first step towards developing neonatal sepsis. Despite this, ESBL-E carriage prevalence and its risk factors during pregnancy or postpartum remain undefined in Southeast-Asia. Objectives To estimate the prevalence of ESBL-E faecal colonization among peripartum women in the community of an urban and a rural area in Cambodia, to investigate ESBL-E genomic characteristics and to identify associated risk factors. Methods Epidemiological data and faecal samples from 423 peripartum women were collected in an urban and rural areas in Cambodia (2015–16). Bacterial cultures, antibiotic susceptibility tests and ESBL gene sequencing were performed. Risk factor analysis was conducted using logistic regression. Results The prevalence of ESBL-E faecal carriage was 79.2% (95% CI 75.0%–82.8%) among which Escherichia coli (n = 315/335, 94.0%) were most frequent. All isolates were multidrug resistant. Among 318 ESBL-E, the genes most frequently detected were blaCTX-M-15 (41.5%), blaCTX-M-55 (24.8%), and blaCTX-M-27 (15.1%). Low income, undernutrition, multiparity, regular consumption of pork, dried meat, and raw vegetables, were associated with ESBL-E faecal carriage. Conclusions The high prevalence of ESBL-E carriage observed among peripartum women in Southeast-Asia and the identified associated factors underline the urgent need for public health measures to address antimicrobial resistance, including a ‘One Health’ approach.

International efforts to curb antimicrobial resistance have focused on drug development and limiting unnecessary use. However, in areas where water, sanitation, and hygiene infrastructure is lacking, and where biosecurity in food-animal production is poor, pathogen-flow between humans and animals could exacerbate the emergence and spread of resistant pathogens. Here, we compared mobile resistance elements among Escherichia coli recovered from humans and meat in Cambodia, a country with substantial connectivity between humans and animals, unregulated antibiotic use, and poor environmental controls. We identified multiple resistance-encoding plasmids and a novel, blaCTX-M and qnrS1-encoding transposon that were widely dispersed in both humans and animals, a phenomenon rarely observed in high-income settings. Our findings indicate that plugging leaks at human-animal interfaces should be a critical part of addressing antimicrobial resistance in low and middle-income countries.

Members of the BIRDY study group : Bodonirina Tanjona Raheliarivao, Frédérique Randrianirina, Perlinot Herindrainy, Zafitsara Zo Andrianirina, Feno Manitra Jacob Rakotoarimanana, Benoit Garin, Jean-Marc Collard, Agathe de Lauzanne, Laurence Borand, Patrice Piola, Alexandra Kerléguer, Thida Chon, Sok Touch, Arnaud Tarantola, Sophie Goyet, Siyin Lach, Veronique Ngo, Muriel Vray, Marguerite Diatta, Joseph Faye, Abibatou Ndiaye, Vincent Richard, Abdoulaye Seck, Raymond Bercion, Amy Gassama Sow, Jean Baptiste Diouf, Pape Samba Dieye, Balla Sy, Bouya Ndao, Didier Guillemot, Bich-tram Huynh, Maud Seguy, Laurence Watier, Abdou Armya Youssouf and Michael Padget.; International audience; BACKGROUND:Salmonella enterica is a leading cause of human gastroenteritis. S. enterica strains that produce ESBLs (ESBL-Salm) remain rare in Europe and North America, but less is known about their prevalence among animal-derived foods in countries with weaker food safety practices and unregulated veterinary antibiotic use.OBJECTIVES:To examine the prevalence and characteristics of ESBL-Salm from retail meats in Phnom Penh, Cambodia.METHODS:We tested fish, pork and chicken from two markets for ESBL- and carbapenemase-producing Salmonella from September-December 2016, using cefotaxime- and ertapenem-supplemented media, respectively. ESBL-Salm were sequenced and their genomes characterized. We performed plasmid conjugation experiments to assess the co-transferability of ESBL-encoding genes and MDR phenotypes.RESULTS:Twenty-six of 150 fish and meat samples (17%) were positive for ESBL-Salm, including 10/60 fish (17%), 15/60 pork (25%) and 1/30 chicken (3%). Carbapenemase-producing Salmonella strains were not detected. Pork-origin ESBL-Salm were primarily serotypes Rissen (10/15) or a monophasic variant of Typhimurium 4,5,12:i:- (3/15), whereas Saintpaul (3/10) and Newport (4/10) were more common among fish. Most ESBL enzymes were encoded by blaCTX-M-55 genes (24/26) harboured on conjugative IncA/C2 (n = 14) or IncHI2 (n = 10) plasmids. Resistance to up to six additional drug classes was co-transferred by each plasmid type. ESBL-Salm were resistant to almost every antibiotic recommended for severe salmonellosis treatment.CONCLUSIONS:CTX-M-55-type S. enterica are highly prevalent among pork and fish from Phnom Penh markets and their spread appears to be mediated by MDR IncA/C2 and IncHI2 plasmids. Food safety must be improved and veterinary antibiotic use should be regulated to protect public health.

The leading cause of hemolytic uremic syndrome (HUS) in children is Shiga toxin-producing Escherichia coli (STEC) infection, which has a major outbreak potential. Since the early 2010s, STEC epidemiology is characterized by a decline of the historically predominant O157 serogroup and the emergence of non-O157 STEC, especially O26 and O80 in France. STEC contamination occurs through the ingestion of contaminated food or water, person-to-person transmission, or contact with ruminants or their contaminated environment. The main symptom is diarrhea, which is bloody in about 60% of patients and occurs after a median incubation period of three days. Shiga toxins released by STEC induce a cascade of thrombogenic and inflammatory changes of microvascular endothelial cells. HUS is observed in 5-15% of STEC infection cases, defined by the triad of mechanical hemolytic anemia, thrombocytopenia, and acute renal injury. The diagnosis of STEC infection relies on biological screening for Shiga toxins and STEC in stools and serology. Treatment of STEC-HUS is mainly symptomatic, as no specific drug has proved effective. The effect of antibiotics in STEC infection and STEC-HUS remains debated; however, some bacteriostatic antibiotics might have a beneficial effect. Proofs of evidence of a benefit from complement blockade therapy in STEC-HUS are also lacking. Clinical and bacteriological STEC-HUS surveillance needs to be continued. Ongoing prospective studies will document the role of bacteriostatic antibiotics in STEC infection and STEC-HUS, and of complement blockade therapy in STEC-HUS.

Introduction Haemolytic uraemic syndrome (HUS) related to Shiga toxin-producing Escherichia coli (STEC) is the leading cause of acute renal failure in young children. In France, HUS surveillance in children aged Aim We present the results of this surveillance between 2007 and 2016. Methods A voluntary nationwide network of 32 paediatric departments notifies cases. Two national reference centres perform microbiological STEC confirmation. Results Over the study period, the paediatric HUS incidence rate (IR) was 1.0 per 100,000 children-years, with a median of 116 cases/year. In 2011, IR peaked at 1.3 per 100,000 children-years, and decreased to 1.0 per 100,000 children-years in 2016. STEC O157 associated HUS peaked at 37 cases in 2011 and decreased to seven cases in 2016. Cases of STEC O26-associated HUS have increased since 2010 and STEC O80 associated HUS has emerged since 2012, with 28 and 18 cases respectively reported in 2016. Four STEC-HUS food-borne outbreaks were detected (three STEC O157 linked to ground beef and raw-milk cheese and one STEC O104 linked to fenugreek sprouts). In addition, two outbreaks related to person-to-person transmission occurred in distinct kindergartens (STEC O111 and O26). Conclusions No major changes in HUS IRs were observed over the study period of 10 years. However, changes in the STEC serogroups over time and the outbreaks detected argue for continuing epidemiological and microbiological surveillance.

Introduction An outbreak of shiga-toxin producing Escherichia coli infections occurred in southwest France in June 2012. The outbreak was investigated to identify the source of infection, and guide control measures. Methods Confirmed outbreak cases were patients who developed bloody diarrhoea or haemolytic uremic syndrome (HUS) between 28 May and 6 July 2012, with E. coli O157 isolates showing indistinguishable patterns on pulse field gel electrophoresis (PFGE). A standardized questionnaire was administered to patients to document food consumption and other risk exposures. Their purchase was checked through their supermarket shopper card data. Results Six patients (four with HUS and two with bloody diarrhea) were confirmed outbreak cases. Fresh ground beef burgers from one supermarket were the only common food exposure, identified by interviews and shopper card data. The PFGE profile of shiga toxin-producing E. coli O157 isolated from the suspected beef burgers was identical to those from the human cases. The suspected beef burgers were no longer on sale at the time of investigation but three patients confirmed as outbreak cases had deep-frozen some at home. Conclusion Shopper card data was particularly useful to obtain precise and reliable information on the traceability of consumed food. Despite the expired use-by date, a recall was issued for the beef burgers. This contributed to preventing other cases among consumers who had deep-frozen the beef burgers.

Shigellosis trends in these communities provide insight into global movement of drug-resistant Enterobacteriaceae., Shigellae are sensitive indicator species for studying trends in the international transmission of antimicrobial-resistant Enterobacteriaceae. Orthodox Jewish communities (OJCs) are a known risk group for shigellosis; Shigella sonnei is cyclically epidemic in OJCs in Israel, and sporadic outbreaks occur in OJCs elsewhere. We generated whole-genome sequences for 437 isolates of S. sonnei from OJCs and non-OJCs collected over 22 years in Europe (the United Kingdom, France, and Belgium), the United States, Canada, and Israel and analyzed these within a known global genomic context. Through phylogenetic and genomic analysis, we showed that strains from outbreaks in OJCs outside of Israel are distinct from strains in the general population and relate to a single multidrug-resistant sublineage of S. sonnei that prevails in Israel. Further Bayesian phylogenetic analysis showed that this strain emerged approximately 30 years ago, demonstrating the speed at which antimicrobial drug–resistant pathogens can spread widely through geographically dispersed, but internationally connected, communities.

This emerging clonal group harbors the extraintestinal virulence–associated plasmid pS88 and can induce invasive infections and death., We describe the epidemiology, clinical features, and molecular characterization of enterohemorrhagic Escherichia coli (EHEC) infections caused by the singular hybrid pathotype O80:H2, and we examine the influence of antibiotics on Shiga toxin production. In France, during 2005–2014, a total of 54 patients were infected with EHEC O80:H2; 91% had hemolytic uremic syndrome. Two patients had invasive infections, and 2 died. All strains carried stx2 (variants stx2a, 2c, or 2d); the rare intimin gene (eae-ξ); and at least 4 genes characteristic of pS88, a plasmid associated with extraintestinal virulence. Similar strains were found in Spain. All isolates belonged to the same clonal group. At subinhibitory concentrations, azithromycin decreased Shiga toxin production significantly, ciprofloxacin increased it substantially, and ceftriaxone had no major effect. Antibiotic combinations that included azithromycin also were tested. EHEC O80:H2, which can induce hemolytic uremic syndrome complicated by bacteremia, is emerging in France. However, azithromycin might effectively combat these infections.

International audience; A widespread belief is that typical hemolytic and uremic syndrome (HUS) does not recur. We report the case of a patient infected twice with raw milk taken from his own cow and containing a Shiga toxin-producing Escherichia coli O174:H21 that induced recurrent HUS causing severe renal and cerebral disorders. A genomic comparison of the human and bovine Shiga toxin-producing Escherichia coli O174:H21 isolates revealed that they were identical. Typical HUS may recur. Since milk from this animal was occasionally distributed locally, thereby posing a serious threat for the whole village, this particular cow was destroyed.

Shigella flexneri is the most common cause of bacterial dysentery in low-income countries. Despite this, S. flexneri remains largely unexplored from a genomic standpoint and is still described using a vocabulary based on serotyping reactions developed over half-a-century ago. Here we combine whole genome sequencing with geographical and temporal data to examine the natural history of the species. Our analysis subdivides S. flexneri into seven phylogenetic groups (PGs); each containing two-or-more serotypes and characterised by distinct virulence gene complement and geographic range. Within the S. flexneri PGs we identify geographically restricted sub-lineages that appear to have persistently colonised regions for many decades to over 100 years. Although we found abundant evidence of antimicrobial resistance (AMR) determinant acquisition, our dataset shows no evidence of subsequent intercontinental spread of antimicrobial resistant strains. The pattern of colonisation and AMR gene acquisition suggest that S. flexneri has a distinct life-cycle involving local persistence. DOI: http://dx.doi.org/10.7554/eLife.07335.001, eLife digest Dysentery is a disease in which the intestine becomes inflamed due to infection by bacteria, viruses or other microbes. Of the bacteria that can cause dysentery, bacteria called Shigella are most often responsible. Humans can acquire Shigella through contaminated food or water. Over the last century, improvements to sanitation combined with access to clean drinking water and better food hygiene have decreased the number of cases of dysentery in many countries. However, the disease continues to be common in low-income countries, especially in young children. One species of Shigella bacteria, called S. flexneri, causes far more cases of dysentry than other species of Shigella. Across the world, there are many different strains of S. flexneri, but it is not clear how these strains are related to each other, or how variable the genes that they carry are—known as genetic diversity. Here, Connor, Barker, Baker et al. used a technique called whole genome sequencing to map the evolutionary relationships of over 300 S. flexneri samples collected from around the globe over the past 100 years. This revealed that the bacterial strains can be split into seven groups that each have distinct geographic ranges and combinations of genes that enable the bacteria to infect humans. Many of the strains of bacteria within these groups seem to have colonized, and remained in, quite small geographic areas over long periods of time. This is different to other Shigella species, which appear to have spread between continents far more frequently over much shorter timescales. Connor, Barker, Baker et al.'s findings reveal that S. flexneri is more diverse than other Shigella bacteria, and suggest that the ability of strains to persist in local areas may have contributed to the species' long-term success. These results point towards the importance of the provision of clean water in the fight against S. flexneri, and underline the need for a greater understanding of how disease-causing bacteria colonize and interact with the local environment. DOI: http://dx.doi.org/10.7554/eLife.07335.002

© 2015 Elsevier Ltd. Background: Shigellosis is an acute, severe bacterial colitis that, in high-income countries, is typically associated with travel to high-risk regions (Africa, Asia, and Latin America). Since the 1970s, shigellosis has also been reported as a sexually transmitted infection in men who have sex with men (MSM), in whom transmission is an important component of shigellosis epidemiology in high-income nations. We aimed to use sophisticated subtyping and international sampling to determine factors driving shigellosis emergence in MSM linked to an outbreak in the UK. Methods: We did a large-scale, cross-sectional genomic epidemiological study of shigellosis cases collected from 29 countries between December, 1995, and June 8, 2014. Focusing on an ongoing epidemic in the UK, we collected and whole-genome sequenced clinical isolates of Shigella flexneri serotype 3a from high-risk and low-risk regions, including cases associated with travel and sex between men. We examined relationships between geographical, demographic, and clinical patient data with the isolate antimicrobial susceptibility, genetic data, and inferred evolutionary relationships. Findings: We obtained 331 clinical isolates of S flexneri serotype 3a, including 275 from low-risk regions (44 from individuals who travelled to high-risk regions), 52 from high-risk regions, and four outgroup samples (ie, closely related, but genetically distinct isolates used to determine the root of the phylogenetic tree). We identified a recently emerged lineage of S flexneri 3a that has spread intercontinentally in less than 20 years throughout regions traditionally at low risk for shigellosis via sexual transmission in MSM. The lineage had acquired multiple antimicrobial resistance determinants, and prevailing sublineages were strongly associated with resistance to the macrolide azithromycin. Eight (4%) of 206 isolates from the MSM-associated lineage were obtained from patients who had previously provided an isolate; these serial isolations indicated atypical infection patterns (eg, reinfection). Interpretation: We identified transmission-facilitating behaviours and atypical course(s) of infection as precipitating factors in shigellosis-affected MSM. The intercontinental spread of antimicrobial-resistant shigella through established transmission routes emphasises the need for new approaches to tackle the public health challenge of sexually transmitted infections in MSM. Funding: Wellcome Trust (grant number 098051).

International audience; BACKGROUND:Although rotavirus is the leading cause of severe diarrhea among children in sub-Saharan Africa, better knowledge of circulating enteric pathogenic bacteria and their antimicrobial resistance is crucial for prevention and treatment strategies.METHODOLOGY/PRINCIPAL FINDINGS:As a part of rotavirus gastroenteritis surveillance in Maradi, Niger, we performed stool culture on a sub-population of children under 5 with moderate-to-severe diarrhea between April 2010 and March 2012. Campylobacter, Shigella and Salmonella were sought with conventional culture and biochemical methods. Shigella and Salmonella were serotyped by slide agglutination. Enteropathogenic Escherichia coli (EPEC) were screened by slide agglutination with EPEC O-typing antisera and confirmed by detection of virulence genes. Antimicrobial susceptibility was determined by disk diffusion. We enrolled 4020 children, including 230 with bloody diarrhea. At least one pathogenic bacterium was found in 28.0% of children with watery diarrhea and 42.2% with bloody diarrhea. Mixed infections were found in 10.3% of children. EPEC, Salmonella and Campylobacter spp. were similarly frequent in children with watery diarrhea (11.1%, 9.2% and 11.4% respectively) and Shigella spp. were the most frequent among children with bloody diarrhea (22.1%). The most frequent Shigella serogroup was S. flexneri (69/122, 56.5%). The most frequent Salmonella serotypes were Typhimurimum (71/355, 20.0%), Enteritidis (56/355, 15.8%) and Corvallis (46/355, 13.0%). The majority of putative EPEC isolates was confirmed to be EPEC (90/111, 81.1%). More than half of all Enterobacteriaceae were resistant to amoxicillin and co-trimoxazole. Around 13% (46/360) Salmonella exhibited an extended-spectrum beta-lactamase phenotype.CONCLUSIONS:This study provides updated information on enteric bacteria diversity and antibiotic resistance in the Sahel region, where such data are scarce. Whether they are or not the causative agent of diarrhea, bacterial infections and their antibiotic resistance profiles should be closely monitored in countries like Niger where childhood malnutrition pre-disposes to severe and invasive infections.

Introduction Trois cas de syndrome hemorragique et uremique (SHU) survenus en 15 jours dans une creche etaient notifies a l’Institut de veille sanitaire (InVS) le 5 novembre 2012 suggerant des cas groupes d’infection a Escherichia coli enterohemorragique (EHEC). Methode Une enquete exploratoire, une enquete de cohorte retrospective aupres de 89/94 enfants (95 %) et de 28/36 (78 %) personnels et une surveillance prospective ont ete realisees pour rechercher une exposition commune et determiner l’ampleur de l’epidemie. Un depistage dans l’entourage familial des cas confirmes et parmi les enfants et personnels a ete realise. Les EHEC ont ete recherches par PCR dans les selles, les echantillons positifs etaient mis en culture pour caracterisation des souches. Un cas confirme etait un enfant ou personnel de la creche ayant presente, entre le 10 octobre 2012 et le 17 janvier 2013, des signes de gastro-enterite et/ou un SHU avec isolement de EHEC O111 ; un cas probable avait presente des selles sanglantes et/ou un SHU et une PCR positive ; un cas possible avait presente une diarrhee avec au moins trois selles liquides en 24 heures et consulte un medecin. Resultats Dix-huit cas (6 confirmes, 1 probable et 11 possibles) ont ete recenses parmi les enfants. La courbe epidemique evoquait une transmission interhumaine. Le taux d’attaque etait de 20,2 %, 6,7 % en considerant uniquement les cas confirmes. La frequentation du groupe A etait associee significativement avec la maladie (RR = 3,1 IC95 % [1,3–7,1]). Parmi les contacts familiaux des cas confirmes, 17 % (3/18) etaient porteurs asymptomatiques. Le depistage a identifie 4 % (3/80) d’enfants porteurs asymptomatiques. Discussion Devant les questions soulevees par la gestion, le Haut Conseil de la sante publique a mis en place en juillet 2013 un groupe d’experts pour elaborer des recommandations et eviter la survenue de cas secondaires d’EHEC dans des collectivites.

International audience; Hemolytic-uremic syndrome due to enterohemorrhagic Escherichia coli, belonging to serogroup O91 hasrarely been described. We report here a case of post-diarrheal HUS due to EHEC O91 in an elderly patientfor whom diagnosis was delayed given a previously diagnosed C. difficile infection. This case highlightsthe usefulness of Shiga-toxin detection.

Escherichia coli O157:H7 producing Shiga like toxins is a food-borne pathogen frequently isolated in Bangui from patients with hemorrhagic colitis (HC). This survey provides comprehensive data on the high prevalence of E. coli O157:H7 infection in Bangui: carriage of E. coli O157:H7 by zebu (Bos indicus) and fish, contamination of the fields at N'Goila where the butchers kill the zebus, and contamination of the field surface water along the M'Poko River upstream of the Oubangui River where fish are caught, appear to be important contributory factors. We also describe novel strains of serogroup O157:NM isolated from zebu and from fish; a variety of assays indicate that these strains belong to the enteropathogenic pathotype, though they lack certain genetic elements thought to be diagnostic for this pathotype.

The large outbreak of diarrhea and hemolytic uremic syndrome (HUS) caused by Shiga toxin-producing Escherichia coli O104:H4 in Europe from May to July 2011 highlighted the potential of a rarely identified E. coli serogroup to cause severe disease. Prior to the outbreak, there were very few reports of disease caused by this pathogen and thus little known of its diversity and evolution. The identification of cases of HUS caused by E. coli O104:H4 in France and Turkey after the outbreak and with no clear epidemiological links raises questions about whether these sporadic cases are derived from the outbreak. Here, we report genome sequences of five independent isolates from these cases and results of a comparative analysis with historical and 2011 outbreak isolates. These analyses revealed that the five isolates are not derived from the outbreak strain; however, they are more closely related to the outbreak strain and each other than to isolates identified prior to the 2011 outbreak. Over the short time scale represented by these closely related organisms, the majority of genome variation is found within their mobile genetic elements: none of the nine O104:H4 isolates compared here contain the same set of plasmids, and their prophages and genomic islands also differ. Moreover, the presence of closely related HUS-associated E. coli O104:H4 isolates supports the contention that fully virulent O104:H4 isolates are widespread and emphasizes the possibility of future food-borne E. coli O104:H4 outbreaks., IMPORTANCE In the summer of 2011, a large outbreak of bloody diarrhea with a high rate of severe complications took place in Europe, caused by a previously rarely seen Escherichia coli strain of serogroup O104:H4. Identification of subsequent infections caused by E. coli O104:H4 raised questions about whether these new cases represented ongoing transmission of the outbreak strain. In this study, we sequenced the genomes of isolates from five recent cases and compared them with historical isolates. The analyses reveal that, in the very short term, evolution of the bacterial genome takes place in parts of the genome that are exchanged among bacteria, and these regions contain genes involved in adaptation to local environments. We show that these recent isolates are not derived from the outbreak strain but are very closely related and share many of the same disease-causing genes, emphasizing the concern that these bacteria may cause future severe outbreaks.

The performance of CHROMagar STEC and CHROMagar STEC O104 (CHROMagar Microbiology, Paris, France) media for the detection of Shiga toxin-producing Escherichia coli (STEC) was assessed with 329 stool specimens collected over 14 months from patients with suspected STEC infections (June 2011 to August 2012). The CHROMagar STEC medium, after an enrichment broth step, allowed the recovery of the STEC strain from 32 of the 39 (82.1%) Shiga toxin-positive stool specimens, whereas the standard procedure involving Drigalski agar allowed the recovery of only three additional STEC strains. The isolates that grew on CHROMagar STEC medium belonged to 15 serotypes, including the prevalent non-sorbitol-fermenting (NSF) O157:H7, O26:H11, and O104:H4 serotypes. The sensitivity, specificity, and positive and negative predictive values for the CHROMagar STEC medium were between 89.1% and 91.4%, 83.7% and 86.7%, 40% and 51.3%, and 98% and 98.8%, respectively, depending on whether or not stx -negative eae -positive E. coli was considered atypical enteropathogenic E. coli (EPEC) or STEC that had lost Shiga toxin genes during infection. In conclusion, the good performance of CHROMagar STEC agar medium, in particular, the high negative predictive value, and its capacity to identify NSF O157:H7 as well as common non-O157 STEC may be useful for clinical bacteriology, public health, and reference laboratories; it could be used in addition to a method targeting Shiga toxins (detection of stx genes by PCR, immunodetection of Shiga toxins in stool specimens, or Vero cell cytotoxicity assay) as an alternative to O157 culture medium. This combined approach should allow rapid visualization of both putative O157 and non-O157 STEC colonies for subsequent characterization, essential for real-time surveillance of STEC infections and investigations of outbreaks.

International audience; Since the 1980s, EnterohaemorrhagicEscherichia coli (EHEC) have been recognised as emergent pathogens causing foodborne outbreaks. The latest one is the E. coli O104:H4 outbreak which occurred in Germany in May 2011 then in France.In France, the surveillance of EHEC infections is based on surveillance of hemolytic-uremic syndrome (HUS) in children under 15 years old. The average annual incidence is 0.8/100,000 children under 15 years old with a predominance of the O157:H7 serotype.EHEC are one of the six clinical pathovars of E. coli defined by their capacity to produce Shiga-toxins and for that reason, are part of a larger group called: Shigatoxin-producingE. coli (STEC).EHEC are a cause of different troubles ranging from mild diarrhea to haemorrhagic colitis which might be complicated by HUS in young children and thrombocytopenic thrombotic purpura in adults.The reservoir of EHEC is mainly the intestinal tract of ruminants: EHEC are transmitted via ingestion of contaminated food or water, person-to-person contact, direct animal contact and exposure to the environment.The diagnosis of the EHEC infections relies on isolation of STEC in stool samples or detection of genes encoding for Shiga-toxins.Treatment is mainly symptomatic. Use of antibiotics is controversial because the risk of HUS could be increased (release of toxins).; Les Escherichia colientérohémorragiques (EHEC) sont considérés depuis les années 1980 comme des pathogènes émergents responsables d’épidémies d’origine alimentaire (la plus récente est celle due à E. coli O104:H4 en mai 2011, en Allemagne puis en France).En France, la surveillance des infections à EHEC repose sur la surveillance des SHU chez les enfants de moins de 15 ans. L’incidence annuelle est de 0,8/100 000 enfants de moins de 15 ans avec prédominance du sérotype O157:H7.Les EHEC constituent l’un des six pathovars définis de l’espèce E. coli caractérisés par leur capacité à produire des cytotoxines de la famille des Shiga-toxines et font partie d’un groupe plus important que l’on appelle les Shiga toxin-producing E. coli (STEC).Les EHEC sont responsables chez l’homme de troubles variés allant d’une simple diarrhée aqueuse bénigne à une colite hémorragique pouvant évoluer vers des formes graves telles que le syndrome hémolytique et urémique (SHU) chez les jeunes enfants et le purpura thrombotique thrombocytopénique chez l’adulte.Le réservoir de ces bactéries est majoritairement le tube digestif des ruminants : la transmission à l’homme se fait principalement par la consommation d’aliments insuffisamment cuits (viande de bœuf notamment), l’eau contaminée, le contact direct avec des animaux ou avec des personnes infectées.Le diagnostic de certitude des infections à EHEC est basé sur la mise en évidence dans les selles, des gènes de virulence et/ou de souches productrices de Shiga-toxines.Le traitement est principalement symptomatique, les antibiotiques étant très controversés car ils favoriseraient le SHU par libération des toxines.

Quantitative data on Campylobacter contamination of food are lacking, notably in developing countries. We assessed Campylobacter contamination of chicken neck-skins at points of slaughter in 5 major cities in Africa (Dakar in Senegal, Yaounde in Cameroon), Oceania (Noumea in New Caledonia), the Indian Ocean (Antananarivo in Madagascar) and Asia (Ho Chi Minh City (HCMC) in Vietnam. One hundred and fifty slaughtered chickens were collected in each of the 5 major cities from semi-industrial abattoirs or markets (direct slaughter by the seller), and 65.5% (491/750) were found to be Campylobacter-positive. Two cities, Yaounde and Noumea, demonstrated high prevalence Campylobacter detection rates (92.7% and 96.7% respectively) in contrast with HCMC (15.3%). Four species were identified among 633 isolates, namely C. jejuni (48.3%), C. coli (37.3%), C. lari (11.7%) and C. upsaliensis (1%). HCMC was the only city with C. lari isolation as was Antananarivo for C. upsaliensis. C. coli was highly prevalent only in Yaounde (69.5%). Among the 491 samples positive in Campylobacter detection, 329 were also positive with the enumeration method. The number of Campylobacter colony-forming units (CFU) per gram of neck-skin in samples positive in enumeration was high (mean of the log(10): 3.2 log(10) CFU/g, arithmetic mean: 7900CFU/g). All the cities showed close enumeration means except HCMC with a 1.81 log(10) CFU/g mean for positive samples. Semi-industrial abattoir was linked to a significant lower count of Campylobacter contamination than direct slaughter by the seller (p=0.006). On 546 isolates (546/633, 86.3%) tested for antibiotic susceptibility, resistance to erythromycin, ampicillin and ciprofloxacin was observed for respectively 11%, 19% and 50%. HCMC was the city where antibiotic resistant rates were the highest (95%, p=0.014). Considering the 329 positive chickens in Campylobacter enumeration, the mean number of resistant isolates to at least 2 different antibiotic families (19.8%), may be estimated ca. 1500CFU/g; the corresponding mean of the log(10) would be 2.5 log(10)CFU/g. As chickens are sold at slaughter and brought directly at home to be cooked, these data suggest a high probability of cross-contamination. A substantial proportion of isolates are drug-resistant, which could lead to potential public health issues. Health authorities should consider measures to reduce Campylobacter contamination of chicken during farming and at slaughter, and to provide appropriate food hygiene education. Further studies are needed in particular to investigate food-handling practices in domestic kitchens.

We previously suggested that the ability to metabolize deoxyribose, a phenotype encoded by the deoK operon, is associated with the pathogenic potential of Escherichia coli strains. Carbohydrate metabolism is thought to provide the nutritional support required for E. coli to colonize the intestine. We therefore investigated the role of deoxyribose catabolism in the colonization of the gut, which acts as a reservoir, by pathogenic E. coli strains. Molecular and biochemical characterization of 1,221 E. coli clones from various collections showed this biochemical trait to be common in the E. coli species (33.6%). However, multivariate analysis evidenced a higher prevalence of sugar-metabolizing E. coli clones in the stools of patients from countries in which intestinal diseases are endemic. Diarrhea processes frequently involve the destruction of intestinal epithelia, so it is plausible that such clones may be positively selected for in intestines containing abundant DNA, and consequently deoxyribose. Statistical analysis also indicated that symptomatic clinical disorders and the presence of virulence factors specific to extraintestinal pathogenic E. coli were significantly associated with an increased risk of biological samples and clones testing positive for deoxyribose. Using the streptomycin-treated-mouse model of intestinal colonization, we demonstrated the involvement of the deoK operon in gut colonization by two pathogenic isolates (one enteroaggregative and one uropathogenic strain). These results, indicating that deoxyribose availability promotes pathogenic E. coli growth during host colonization, suggest that the acquisition of this trait may be an evolutionary step enabling these pathogens to colonize and persist in the mammalian intestine.

Several reports have described Listeria monocytogenes strains which were nonpathogenic or weakly pathogenic, but little is known about these low-virulence strains. We found that 9 field L. monocytogenes strains were hypovirulent and 17 were avirulent, based on the number of mice contaminated and the colonization of their spleens after subcutaneous inoculation. All these strains possessed the known virulence genes. We have now assessed the low virulence of these strains in other assays before determining how they differ from virulent strains. We have shown that the low-virulence strains exhibited a phenotypic stability and were not a mixture of virulent and avirulent bacteria. They did not recover virulence after many passages in mice and colonized the spleens of mice more poorly than virulent strains after i.v. inoculation. Their lethal capacities, determined by 50% lethal dose (LD 50 ), were lower than those of virulent strains. Like Listeria innocua , 14 of 17 avirulent strains had no LD 50 and were eliminated by the lymph nodes after subcutaneous inoculation. The virulent, hypovirulent, and avirulent strains were always significantly different, whatever the tests of virulence used, confirming the importance of these low-virulence field strains in identifying the proteins involved in virulence.

Introduction Le 22 juillet 2013, des cas de gastro-enterite aigue lors d’un festival musical en Ariege ont ete signales a l’Agence regionale de sante Midi-Pyrenees. Ce festival etait organise du 19 au 21 juillet et regroupait environ 300 benevoles, 150 artistes et 3500 festivaliers provenant de France et d’autres pays europeens. Methode Des investigations epidemiologiques et microbiologiques ont ete menees afin de confirmer l’existence d’une epidemie, de la decrire, d’identifier l’agent responsable, et de preciser le mode de transmission. Un cas confirme a ete defini par une coproculture positive a Shigella chez un participant du festival. Un cas possible a ete defini par la survenue d’une diarrhee aigue chez un participant au festival ou chez une personne ayant ete en contact avec un cas confirme. Compte tenu de la dispersion geographique des participants, les investigations ont implique des contacts avec differents partenaires europeens. Resultats Au total, 171 cas ont ete identifies dont 28 confirmes. La majorite (71 %) est survenue parmi les benevoles. Les symptomes rapportes–diarrhees (100 %) dont diarrhees glairo-sanglantes (13 %), douleurs abdominales (74 %), fievre (70 %), nausees/vomissements (65 %)–sont apparus entre le 18 juillet et le 10 aout, avec un pic le 21 juillet. Conclusion Plusieurs modes de transmission ont ete suspectes : alimentaire, inter-humain et environnemental, favorises par des conditions d’hygiene precaires. Un lien epidemiologique et microbiologique a ete etabli avec une epidemie de shigellose survenue lors d’un festival en Espagne du 9 au 14 juillet, presentant la meme souche de Shigella sonnei, de profil d’antibiogramme identique.

To the Editor: During the rainy season, from April to September 2003, 463 children ≤15 years of age (median 10 months) with severe diarrhea were admitted to the Pediatric Hospital of Kalembelembe in Kinshasa, the capital of the Democratic Republic of Congo. The population of the outbreak area was approximately one million. Several children with bloody diarrhea without fever were treated. They came from six districts of Kinshasa (Bumbu, Selembao, Makala, Kimbanseke, Masina, and Ndjili). Abdominal cramps, nausea, vomiting, and dehydration were uncommon. The duration of illness ranged from 5 days to 2 weeks. Available antiparasitic drugs, trimethoprim-sulfamethoxazole, and ampicillin showed no effect against the illness. Fifty-six infants died between June and July. Symptoms of hemolytic-uremic syndrome developed in most of them. Stool samples from 32 patients were screened for parasites, enteropathogenic bacteria, rotavirus, and adenovirus. Three samples were positive for rotavirus. In contrast, all stool cultures were positive for Escherichia coli which always grew as pure cultures on purple bromocresol agar, a nonselective medium containing lactose. The E. coli isolates appeared sorbitol negative when tested on MacConkey sorbitol; they were agglutinated by O157 and H7 antisera (Difco Laboratories, Detroit, MI) and lacked expression of β-glucuronidase. All E. coli isolates were sent to the Pasteur Institute in Bangui, Central African Republic, for further characterization. Polymerase chain reaction allowed detection of Shiga-like toxin slt-1 and slt-2 genes (1,2) in isolates from all patients. The Vero cell assay phenotypically confirmed cytotoxicity of these isolates, with most of them being seroneutralized by rabbit antisera against Shiga toxin (3). Thus, all E. coli isolates responded to the definition of enterohemorrhagic E. coli. Before 2003, sporadic infections or outbreaks caused by enterohemorrhagic E. coli were not reported as a cause of bloody diarrhea in the Democratic Republic of Congo. A case-control study could not be performed because of political unrest in Kinshasa. Although reported outbreaks of E. coli O157 in sub-Saharan Africa have been few to date, available information indicates that the pathogen has wide geographic distribution. E. coli O157–related diarrhea outbreaks that occurred before 2003 have been reported in South Africa, Swaziland (4), and Malawi (5) in 1992; Central African Republic (6) and Kenya (7) in 1996; Cameroon in 1998 (8); and Nigeria (9) and Ivory Coast (10) in 2000. In the Central African Republic and in Zemio, a small village located on the Democratic Republic of Congo border, outbreaks of bloody diarrhea in 1996 were attributed to E. coli O157 from molecular test results (6). Since 2001, an increasing number of cases of acute bloody diarrhea have been reported in Kinshasa between June and August. During this 2003 outbreak, an investigation could not be conducted; possible routes of transmission would include person-to-person contact related to lack of hygiene, and contaminated food and water. In 1996 in the Central African Republic and in 1998 in Cameroon, the major contributing factors of the E. coli O157 outbreak were consumption of smoked zebu meat and contaminated drinking water. Studies of E. coli O157 carriage rates among livestock, food, and environment in this central African area might be useful in assessing the potential for future outbreaks. Hemolytic-uremic syndrome occurs in approximately 8% of children and an unknown proportion of adults infected with E. coli O157 and can be fatal without hemodialysis. The high death rate of infants during this outbreak was linked to the lack of treatment (mainly hemodialysis) at the beginning of the epidemic. Obviously, more work is needed to better define the incidence and epidemiology of E. coli–associated diarrhea in the Democratic Republic of Congo so that optimal recommendations for preventing and managing illness can be developed.

International audience; Sorbitol-fermenting Escherichia coli O157:[H7] is a particularly virulent clone of E. coli O157:H7 associated with a higher incidence of haemolytic uraemic syndrome and a higher case fatality rate. Many fundamental aspects of its epidemiology remain to be elucidated, including its reservoir and transmission routes and vehicles. We describe an outbreak of sorbitol-fermenting E. coli O157:[H7] that occurred in France in 2011. Eighteen cases of paediatric haemolytic uraemic syndrome with symptom onset between 6 June and 15 July 2011 were identified among children aged 6 months to 10 years residing in northern France. A strain of sorbitol-fermenting E. coli O157:[H7] stx2a eae was isolated from ten cases. Epidemiological, microbiological and trace-back investigations identified multiply-contaminated frozen ground beef products bought in a supermarket chain as the outbreak vehicle. Strains with three distinct pulsotypes that were isolated from patients, ground beef preparations recovered from patients' freezers and from stored production samples taken at the production plant were indistinguishable upon molecular comparison. This investigation documents microbiologically confirmed foodborne transmission of sorbitol-fermenting of E. coli O157 via beef and could additionally provide evidence of a reservoir in cattle for this pathogen.

International audience; Eight cases of diarrhoea, including two cases of haemolytic uraemic syndrome (HUS), were identified among 22 French tourists who travelled to Turkey in September 2011. A strain of Escherichia coli O104:H4 stx2-positive, eae-negative, hlyA-negative, aggR-positive, ESBL-negative was isolated from one HUS case. Molecular analyses show this strain to be genetically similar but not indistinguishable from the E. coli O104:H4 2011 outbreak strain of France and Germany. Although the source of infection was not identified, we conclude that the HUS cases had probably been infected in Turkey.

International audience; Shiga toxins (Stxs) are potent cytotoxins that inhibit host cell protein synthesis, leading to cell death. Classically, these toxins are associated with intestinal infections due to Stx-producing Escherichia coli or Shigella dysenteriae serotype 1, and infections with these strains can lead to haemolytic-uraemic syndrome. Over the past decade, there has been increasing recognition that Stx 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 Centre for Escherichia coli, Shigella and Salmonella collection to survey the frequency of Stx-producing Shigella species isolated from French travellers returning from the Caribbean. Approximately 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 travellers who were infected with Stx-producing Shigella had recently travelled to Haiti, the Dominican Republic, or French Guiana. Furthermore, whole genome sequencing showed that the toxin genes were encoded by a prophage that was highly identical to the phage that 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.