Objective: To investigate faecal contamination and safety of Rastrineobola argentea sold in retail markets in Kisumu town. Design: This was a repeated cross sectional study and based on random sampling. Setting: Kisumu city, targeting six markets; Oile, Jubilee, Kibuye, Kondele, Nyalenda and Manyatta. Results: A total of 60 fish samples were analysed. All the fish were found to be contaminated with E. coli, and in addition 6.67% of the fish products tested positive for Salmonella. Shigella was absent in all samples analysed. 26.53% of E. coli isolates tested were resistant to two or more antimicrobial agents tested, with the highest level of resistance detected against cotrimoxazole at 38.76%. The E. coli multiple antibiotic resistance (MAR) index was 0.084 indicating that the contamination was not originating from a high -risk source. A plasmid of approximately 5.6 kb was commonly isolated from E. coli isolates that showed resistance to ampicillin. Plasmids isolated were not transferable by conjugation. Conclusion: The presence of Salmonella spp and occurrence of MDR E. coli were identified as some of the possible health risks that may be associated with R. argentea displayed for sale in Kisumu city markets. This possess a real health risk through consumption or directly through contact with the fish products.

Lake Victoria the second largest fresh water body in the world located in East Africa is a shared resource between Kenya, Tanzania and Uganda and enjoys a wide range of streams and rivers from as far as Burundi and Rwanda. The lake has environmentally undergone physical, chemical and biological changes in the last four decades, particularly rise in its trophic condition and decline in oxygen level, which affects the water quality and fish population dynamics. This study therefore set out to determine the quality of water in selected fishing beaches of Lake Victoria, Kenya with a view to report the possible pollution levels. pH was highest at Nyamasari and Kotieno (9.3 ± 0.1) and lowest at Nyachebe and Kichinjio (7.08 ± 0.1) whereas temperature was highest at Nyamasari (29.5˚C ± 0.0˚C) and lowest at Kichinjio (23.4˚C ± 0.2˚C). DO was highest at Kotieno (10.3 ± 0.2 mgL) and lowest at Seka (2.4 ± 0.1 mgL). Turbidity was highest at Uyoga (125.5 ± 0.90 NTU) and lowest at Osieko (2.7 ± 0.1 NTU). Ammoniacal nitrogen was highest at Dunga (1278.3 ± 0.8 μg•l −1) and lowest at Nyamasari (12.4 ± 0.8), all a factor of human activities, lake substratum and effluents from rivers and surface runoff. All parameters assessed showed significant differences across sampling sites and depth except pH which did not vary significantly with distance from lakeshore. Further, all parameters did not show a clear pattern with respect to distance from the lakeshore possibly due to adequate mixing in the gulf. There is a need for further water quality monitoring by seasons to inform policy decisions towards sustainable lake exploitation.

Diarrheal diseases often attributable to poor sanitary conditions and fecal contamination of drinking water remain a leading cause of mortality for children younger than five years. Water contaminated with human faeces, for example from municipal sewage, septic tanks and latrines, is of particular concern. Animal faeces also contain microorganisms that can cause diarrhea. Kakamega County in Kenya has a diarrhea prevalence rate of 20.2%, which is the highest in the country; a good proportion of these cases are believed to be water borne. This study was designed to determine Original Research Article

S TUDIES have demonstrated high levels of ampicillin resistance among Escherichia coli occurring in wastewater and environmental systems in western Kenya. The current study investigated antimicrobial resistance profiles and biofilm formation abilities in presence and absence of sub-lethal ampicillin concentrations, of E. coli recovered from final sedimentation ponds of two wastewater treatment plants in Kakamega municipality. 34 non-duplicate E. coli isolates were recovered by direct plating of wastewater sample aliquots on MacConkey agar and their biofilm formation capabilities measured by crystal violet assay while disc diffusion and Polymerase Chain Reaction (PCR) techniques were used to determine their antibiotic resistance levels and ampicillin resistance genes respectively. The Spearman's Chi-square test at P≤ 0.05 was used to check for interdependence between antimicrobial resistance and biofilm formation capabilities. 58.8% of the isolates were multi-drug resistant (MDR) and 85.3% showed resistance to ampicillin, which was found to be encoded by bla TEM in 65% and bla SHV in 8.8%. The biofilm phenotype was exhibited by 61.8% of all the isolates, amongst which 23.6% showed a strong, 14.7% a moderate and 23.6% a weak propensity to form biofilms. This study revealed lack of association between antibiotic resistance and biofilm formation, but interestingly, ampicillin concentration of 8.0µg/ml triggered the highest biofilm biomass among the isolates. The findings drive at the conclusion that biofilm production among E. coli in wastewater treatment plants(WWTPs) does not correlate with antibiotic resistance, but may be an important protection mechanism against sub-lethal antimicrobial levels present in environmental milieu.

The study compares Escherichia coli recovered from human, fish products, domesticated animals and the environment within the Lake Victoria basin on the basis of their antimicrobial susceptibility profiles. A total of 134 E. coli isolates were isolated from the collected samples. 52.2% of the E. coli isolates were found to be resistant to at least one antibiotic. Isolates originating from fish and soil showed the highest levels of resistance (100%). Based on the discriminant analysis (DA), most of the fish isolates were misclassified into soil category, probably due to the groups displaying similar Multiple Antibiotic Resistance (MAR) profiles. On the other hand, human isolates had the highest score of 0.55. The findings suggest that soil may be an important source of bacterial contamination of fish. Similarly resistance to antibiotics is widely prevalent among human, environment and domesticated animals within the Lake Victoria basin.