This study investigated the prevalence, serotypes and antimicrobial sensitivity patterns of Salmonella enterica in environment in Ouagadougou, Burkina Faso. A total of 476 samples, consisting of 36 samples of tap water, 51 samples of well water, 87 samples of channel water, 44 samples of reservoir water, 238 samples of fish, and 20 samples of lettuce were examined using standard bacteriological procedures for Salmonella. Salmonella were isolated from 98 samples. Salmonella were rare in drinking water, since they were not found at all from the tap water, and only in 2 % of well water. Salmonella were more common in the water of reservoir of Tanghin (15 %), reservoir of Yamtenga (20 %), and in the water channels in the city (from 20 to 31 %). Salmonella were commonly isolated from the fish (24 %) caught from the reservoir of Tanghin and from the lettuce (50 %) irrigated with water from Tanghin. The Salmonella isolates were found to represent 50 different serotypes. The 11 most common serotypes were Salmonella Bredeney and S. Colindale (both 8.2 %), S. Muenster (6.1 %), S. Korlebu (5.1 %), S. Eastbourne and S. Poona (both 4.1 %), and S. Agona, S. Derby, S. Drac, S. Senftenberg, S. Waycross (each 3.1 %), accounting for 51.3 % of all the isolates. In general, the Salmonella strains were sensitive to the antimicrobials tested, but two strains were resistant to streptomycin and many more intermediate to streptomycin or sulphonamide. This study highlights the common prevalence of Salmonella and the high diversity of Salmonella serotypes in aquatic environment in Ouagadougou, Burkina Faso. Therefore, various human activities linked to water and consumption of water-related products, such as fish and lettuce, can lead to human Salmonella infections.

Vegetable production in urban gardens of Ouagadougou contributes to food security, but water for irrigation is often of low quality. This is particularly acute if irrigation water is taken from wastewater polluted channels. This study aimed at (i) verifying to what degree irrigation water quality is correlated with contamination of lettuce with Escherichia coli, total coliforms, and Salmonella spp., and (ii) assessing effects of post-harvest handling on pathogen development during the trade chain. We tested pathogen removal efficiency on lettuce by applying post-harvest washing. Irrigation water of production areas in Ouagadougou (n = 10) showed a mean E. coli load of 2.1 × 10⁵ CFU 100 mL⁻¹. In 60% of the cases, irrigation water did not meet the standards of the World Health Organization (WHO) for safe irrigation water, and in 30% of the cases, irrigation water was contaminated with Salmonella spp. Loads of total coliforms on lettuce leaves ranged from 2.9 × 10³ CFU g⁻¹ to 1.3 × 10⁶ CFU g⁻¹, while E. coli averaged 1.1 × 10² CFU g⁻¹. Results on post-harvest handling revealed that microbial loads increased along the trade chain. Overall, half of all lettuce samples (n = 60) were tested positively for Salmonella spp. The experiment showed that appropriate post-harvest handling could prevent the increase of total coliforms.

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.

Ouagadougou is a city with three million inhabitants and an increasing demand for water of sufficient quality. New boreholes are drilled to match demand, but their protection from anthropogenic contamination is insufficient. To assess the quality of urban groundwater in Ouagadougou for the first time, a total of 32 borehole water samples were collected and assessed for bacteriological and physicochemical features using established methods. Health risk inspections and hazard assessments were undertaken at sampling sites to identify potential hazards and contributing factors. Statistical analysis was used to identify associations between risk factors and water pollution. The study revealed poor quality of groundwater in Ouagadougou with major nonconformities related to total coliforms, Escherichia coli, and turbidity. Water samples from 19 boreholes (59%) were contaminated with coliforms, and 11 (34%) with E. coli. Additionally, Pseudomonas aeruginosa, Enterococcus, and anaerobic sulphite-reducing bacterial spores were detected. Deviations from physicochemical quality requirements were observed for water turbidity, pH, nitrate, fluorine, and iron. Risk analysis showed the major high-risk practices to be sludge spreading or having a garbage heap, a latrine, a septic tank, or dirty water near a borehole. Based on these results, for public health protection, authorities must take strict measures to prohibit such practices around these important sources of drinking water in Ouagadougou.

Objectives: In Burkina Faso (BF), dirty water, in particular those of the stoppings and the gutter are used for irrigation of vegetables. The aim of this study is to contribute to the knowledge on the molecular level of Salmonella Typhi and Paratyphi circulating in the hospitals and environment next to hospitals in BF. Methods: Salmonella Typhi and Paratyphi strains isolated from patients between 2009 to 2015 and lettuce samples isolated in 2014 in BF were characterized by simple PCR using specific primers. Results: Out of 100 Salmonella isolated, 53% were from human and 47% from lettuce samples. Globally, the highest prevalence was observed with inv A, mis L, pip D, orf L and spv R genes in 97%, 96%; 74%; and 21%. Forty of these isolates carried class 1 integron, 31 from clinical samples and 9 from lettuce samples. Sequencing showed seven different gene cassette arrangements, with aadA1 in 13/15 strains, aadA7 and aac(3)-Id in 2/15 strains. Eight percent (8/100) of Salmonella harbored gyrB and parE genes with 6 from clinical and 2 from lettuce isolates. Sequencing showed no mutation in these genes. Three distinct PFGE types were observed from clinical samples with 90-95% similarity in each case. All Salmonella from lettuce had similar pulsotypes. Conclusion: This study showed the diversity virulence and resistance genes harbored of S. Typhi and Paratyphi from both clinical and lettuce samples in BF. Lettuce is a potential source of transmission of Salmonella causing diarrhea among human in BF.