Genetic Diversity and Virulence Potential of Shiga Toxin-Producing Escherichia coli O113:H21 Strains Isolated from Clinical, Environmental, and Food Sources

Shiga toxin-producing Escherichia coli strains of serotype O113:H21 have caused severe human diseases, but they are unusual in that they do not produce adherence factors coded by the locus of enterocyte effacement. Here, a PCR microarray was used to characterize 65 O113:H21 strains isolated from the environment, food, and clinical infections from various countries. in comparison to the pathogenic strains that were implicated in hemolytic-uremic syndrome in Australia, there were no clear differences between the pathogens and the environmental strains with respect to the 41 genetic markers tested. Furthermore, all of the strains carried only Shiga toxin subtypes associated with human infections, suggesting that the environmental strains have the potential to cause disease. Most of the O113:H21 strains were closely related and belonged in the same clonal group (ST-223), but CRISPR analysis showed a great degree of genetic diversity among the O113:H21 strains.French Joint Ministerial Program of R&D against CBRNE RisksFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Food & Drug Adm, Div Microbiol, College Pk, MD 20740 USAFrench Agcy Food Environm & Occupat Hlth & Safety, Lab Food Safety, Maisons Alfort, FranceFood & Drug Adm, Div Mol Biol, Laurel, MD USAUniversidade Federal de São Paulo, Dept Microbiol Immunol & Parasitol, São Paulo, BrazilFed Inst Risk Assessment, Natl Reference Lab Escherichia coli, Berlin, GermanyInst Nacl Enfermedades Infecciosas ANLIS Dr Carlo, Serv Fisiopatogenia, Buenos Aires, DF, ArgentinaUniv Melbourne, Peter Doherty Inst Infect & Immun, Dept Microbiol & Immunol, Melbourne, Vic, AustraliaUniv Adelaide, Res Ctr Infect Dis, Sch Mol & Biomed Sci, Adelaide, SA, AustraliaUniversidade Federal de São Paulo, Dept Microbiol Immunol & Parasitol, São Paulo, BrazilFrench Joint Ministerial Program of R&D against CBRNE Risks: C17609-2Web of Scienc

Diarrheagenic enteroaggregative Escherichia coli causing urinary tract infection and bacteremia leading to sepsis

We report a case of a 55-year-old immunocompromised female who presented to the emergency department with severe diarrhea and vomiting following travel to the Philippines. Stool bacteriology revealed a mixed infection involving an enteropathogenic Escherichia coli and two distinct strains of enteroaggregative Escherichia coli (EAEC). During hospitalization, urine and blood culture tested positive for one of the diarrheagenic EAEC strains, necessitating urinary catheterization, intensive care, and antimicrobial treatment with trimethoprim-sulfamethoxazole, followed by meropenem. Although known to occasionally cause urinary tract infections, EAEC have not been previously associated with sepsis. Our report highlights the potential of EAEC to cause severe extraintestinal infections

Forest Fragmentation as Cause of Bacterial Transmission among Nonhuman Primates, Humans, and Livestock, Uganda

Anthropogenic disturbance increases bacterial transmission

Investigation of an Escherichia coli O145 outbreak in a child day-care centre - extensive sampling and characterization of eae- and stx1-positive E. coli yields epidemiological and socioeconomic insight

<p>Abstract</p> <p>Background</p> <p>On October 29^th2009 the health authorities in the city of Trondheim, Norway were alerted about a case of Shiga toxin-positive <it>E. coli </it>(STEC) O145 in a child with bloody diarrhoea attending a day-care centre. Symptomatic children in this day-care centre were sampled, thereby identifying three more cases. This initiated an outbreak investigation.</p> <p>Methods</p> <p>A case was defined as a child attending the day-care centre, in whom <it>eae- </it>and <it>stx</it>₁- but not <it>stx</it>₂-positive <it>E. coli </it>O145:H28 was diagnosed from a faecal sample, with multilocus variable number of tandem repeat analysis (MLVA) profile identical to the index isolate. All 61 children, a staff of 14 in the day-care centre, and 74 close contacts submitted faecal samples. Staff and parents were interviewed about cases' exposure to foods and animals. Faecal samples from 31 ewes from a sheep herd to which the children were exposed were analyzed for <it>E. coli </it>O145.</p> <p>Results</p> <p>Sixteen cases were identified, from which nine presented diarrhoea but not haemolytic uremic syndrome (HUS). The attack rate was 0.26, and varied between age groups (0.13-0.40) and between the three day-care centre departments (0.20-0.50), and was significantly higher amongst the youngest children. Median duration of shedding was 20 days (0-71 days). Children were excluded from the day-care centre during shedding, requiring parents to take compassionate leave, estimated to be a minimum total of 406 days for all cases. Atypical enteropathogenic <it>E. coli </it>(aEPEC) were detected among 14 children other than cases. These isolates were genotypically different from the outbreak strain. Children in the day-care centre were exposed to faecal pollution from a sheep herd, but <it>E. coli </it>O145 was not detected in the sheep.</p> <p>Conclusions</p> <p>We report an outbreak of <it>stx</it>₁- and <it>eae-</it>positive STEC O145:H28 infection with mild symptoms among children in a day-care centre. Extensive sampling showed occurrence of the outbreak strain as well as other STEC and aEPEC strains in the outbreak population. MLVA-typing of the STEC-isolates strongly indicates a common source of infection. The study describes epidemiological aspects and socioeconomic consequences of a non-O157 STEC outbreak, which are less commonly reported than O157 outbreaks.</p

Intestinal lesions in dogs with acute hemorrhagic diarrhea syndrome associated with netF-positive Clostridium perfringens type A

Acute hemorrhagic diarrhea syndrome (AHDS), formerly named canine hemorrhagic gastroenteritis, is one of the most common causes of acute hemorrhagic diarrhea in dogs, and is characterized by acute onset of diarrhea, vomiting, and hemoconcentration. To date, histologic examinations have been limited to postmortem specimens of only a few dogs with AHDS. Thus, the aim of our study was to describe in detail the distribution, character, and grade of microscopic lesions, and to investigate the etiology of AHDS. Our study comprised 10 dogs with AHDS and 9 control dogs of various breeds, age, and sex. Endoscopic biopsies of the gastrointestinal tract were taken and examined histologically (H&E, Giemsa), immunohistochemically (Clostridium spp., parvovirus), and bacteriologically. The main findings were acute necrotizing and neutrophilic enterocolitis (9 of 10) with histologic detection of clostridia-like, gram-positive bacteria on the necrotic mucosal surface (9 of 10). Clostridium perfringens isolated from the duodenum was identified as type A (5 of 5) by multiplex PCR (5 of 5). In addition, each of the 5 genotyped isolates encoded the pore-forming toxin netF. Clostridium spp. (not C. perfringens) were cultured from duodenal biopsies in 2 of 9 control dogs. These findings suggest that the pore-forming netF toxin is responsible for the necrotizing lesions in the intestines of a significant proportion of dogs with AHDS. Given that the stomach was not involved in the process, the term acute hemorrhagic diarrhea syndrome seems more appropriate than the frequently used term hemorrhagic gastroenteritis

Enteroaggregative escherichia coli have evolved independently as distinct complexes within the E. Coli population with varying ability to cause disease

Enteroaggregative E. Coli (EAEC) is an established diarrhoeagenic pathotype. The association with virulence gene content and ability to cause disease has been studied but little is known about the population structure of EAEC and how this pathotype evolved. Analysis by Multi Locus Sequence Typing of 564 EAEC isolates from cases and controls in Bangladesh, Nigeria and the UK spanning the past 29 years, revealed multiple successful lineages of EAEC. The population structure of EAEC indicates some clusters are statistically associated with disease or carriage, further highlighting the heterogeneous nature of this group of organisms. Different clusters have evolved independently as a result of both mutational and recombination events; the EAEC phenotype is distributed throughout the population of E. coli

Whole genome sequencing reveals high clonal diversity of Escherichia coli isolated from patients in a tertiary care hospital in Moshi, Tanzania

Abstract Background Limited information regarding the clonality of circulating E. coli strains in tertiary care hospitals in low and middle-income countries is available. The purpose of this study was to determine the serotypes, antimicrobial resistance and virulence genes. Further, we carried out a phylogenetic tree reconstruction to determine relatedness of E. coli isolated from patients in a tertiary care hospital in Tanzania. Methods E. coli isolates from inpatients admitted at Kilimanjaro Christian Medical Centre between August 2013 and August 2015 were fully genome-sequenced at KCMC hospital. Sequence analysis was done for identification of resistance genes, Multi-Locus Sequence Typing, serotyping, and virulence genes. Phylogeny reconstruction using CSI Phylogeny was done to ascertain E. coli relatedness. Stata 13 (College Station, Texas 77,845 USA) was used to determine Cohen’s kappa coefficient of agreement between the phenotypically tested and whole genome sequence predicted antimicrobial resistance. Results Out of 38 E. coli isolates, 21 different sequence types (ST) were observed. Eight (21.1%) isolates belonged to ST131; of which 7 (87.5.%) were serotype O25:H4. Ten (18.4%) isolates belonged to ST10 clonal complex; of these, four (40.0%) were ST617 with serotype O89:H10. Twenty-eight (73.7%) isolates carried genes encoding beta-lactam resistance enzymes. On average, agreement across all drugs tested was 83.9%. Trimethoprim/sulphamethoxazole (co-trimoxazole) showed moderate agreement: 45.8%, kappa =15% and p = 0.08. Amoxicillin-clavulanate showed strongest agreement: 87.5%, kappa = 74% and p = 0.0001. Twenty-two (57.9%) isolates carried virulence factors for host cells adherence and 25 (65.7%) for factors that promote E. coli immune evasion by increasing survival in serum. The phylogeny analysis showed that ST131 clustering close together whereas ST10 clonal complex had a very clear segregation of the ST617 and a mix of the rest STs. Conclusion There is a high diversity of E. coli isolated from patients admitted to a tertiary care hospital in Tanzania. This underscores the necessity to routinely screen all bacterial isolates of clinical importance in tertiary health care facilities. WGS use for laboratory-based surveillance can be an effective early warning system for emerging pathogens and resistance mechanisms in LMICs