Occurrence of Vibrio cholerae in fish and water from a reservoir and a neighboring channel in Ouagadougou, Burkina Faso.

INTRODUCTION: Vibrio cholerae is a human pathogen and natural inhabitant of aquatic environments. In this study, we surveyed the occurrence of V. cholerae in fish harvested from a reservoir that receives discharges from the population in Ouagadougou through several channels. METHODOLOGY: A total of 238 fish and 80 water samples were analyzed for the presence of V. cholerae. RESULTS: Altogether, 13 V. cholerae strains were isolated. They were all identified as non-O1/non-O139 V. cholerae without the ctxA gene. The strains were mostly susceptible to the antimicrobials tested. CONCLUSION: Although no strains of epidemic V. cholerae serotypes were encountered, it is important to monitor the microbiological quality of this extensively used water resource and its fish.

Prevalence of diarrheagenic Escherichia coli virulence genes in the feces of slaughtered cattle, chickens, and pigs in Burkina Faso.

We investigated the prevalence of the virulence genes specific for five major pathogroups of diarrheagenic Escherichia coli (DEC) in primary cultures from feces of animals slaughtered for human consumption in Burkina Faso. For the study, 704 feces samples were collected from cattle (n = 304), chickens (n = 350), and pigs (n = 50) during carcass processing. The presence of the virulence-associated genes in the mixed bacterial cultures was assessed using 16-plex polymerase chain reaction (PCR). Virulence genes indicating presence of DEC were detected in 48% of the cattle, 48% of the chicken, and 68% of the pig feces samples. Virulence genes specific for different DECs were detected in the following percentages of the cattle, chicken, and pig feces samples: Shiga toxin-producing E. coli (STEC) in 37%, 6%, and 30%; enteropathogenic E. coli (EPEC) in 8%, 37%, and 32%; enterotoxigenic E. coli (ETEC) in 4%, 5%, and 18%; and enteroaggregative E. coli (EAEC) in 7%, 6%, and 32%. Enteroinvasive E. coli (EIEC) virulence genes were detected in 1% of chicken feces samples only. The study was the first of its kind in Burkina Faso and revealed the common occurrence of the diarrheal virulence genes in feces of food animals. This indicates that food animals are reservoirs of DEC that may contaminate meat because of the defective slaughter and storage conditions and pose a health risk to the consumers in Burkina Faso.

Characterization of Shigatoxigenic Escherichia coli strains from Burkina Faso.

Shigatoxigenic Escherichia coli (STEC) cause serious foodborne infections that lead to diarrheal disease and sequelae worldwide. In Burkina Faso, West Africa, STEC strains from environmental and human sources have not been isolated and characterized before. In this study, 21 STEC strains were isolated from food samples of animal origin and human feces using colony hybridization of the Shiga toxin gene stx. The STEC strains belonged to 15 different serotypes, including O43:H2, O8:H(-), and O2:H2. All strains were positive for stx(1) and 10 also for stx(2). The most common stx(1) subtype was stx(1a), and the most common stx(2) subtype was stx(2b). In five strains, stx(2) subtypes stx(2a) and/or stx(2c), which were previously associated with hemolytic uremic syndrome, were present. Some of the strains possessed the gene saa, encoding autoagglutinating adhesin. None of the strains possessed the gene eae, encoding intimin. Two STEC strains carried also an enterotoxigenic E. coli-associated gene estIa, encoding heat-stable enterotoxin. The STEC isolated from food in Burkina Faso are potentially pathogenic for humans based on the virulence gene combinations that they possess and phenotypes that they express.

Diarrheagenic Escherichia coli detected by 16-plex PCR in raw meat and beef intestines sold at local markets in Ouagadougou, Burkina Faso.

The study investigated the prevalence of five major Escherichia coli pathogroups in raw meats and beef intestines sold at the local markets in Ouagadougou, Burkina Faso. One hundred and twenty samples (36 beef, 36 beef intestine, 24 mutton and 24 chicken samples) were purchased from four markets between October 2008 and February 2009. Fifteen virulence genes specific for Shiga toxin-producing E. coli (STEC), enteropathogenic E. coli (EPEC), enterotoxigenic E. coli (ETEC), enteroinvasive E. coli (EIEC) and enteroaggregative E. coli (EAEC) were examined using 16-plex PCR for mixed bacterial cultures derived from the samples. One or more diarrheagenic E. coli pathogroup was detected in 51 (43%) of all the 120 samples: in 16 (44%) beef, 19 (53%) beef intestine, 9 (38%) mutton and in 7 (29%) chicken samples. Thirty three (28%) samples were positive for stx(1) and/or stx(2) indicating presence of STEC. EPEC virulence markers (eae, escV and/or ent and/or bfp and/or EHEC-hlyA) were detected in 14 (12%) stx-negative samples. ETEC virulence markers (elt and/or estIb and/or estIa) were detected in 10 (8%) samples and EAEC virulence markers (pic or aggR) in 5 (4%) samples. No EIEC was detected. The results show that in Burkina Faso the microbiological quality of retail meat is alarmingly poor due to the common occurrence of diarrheagenic E. coli bacteria.