Isolation of Salmonella and Shigella from fish harvested from the Winam Gulf of Lake Victoria, Kenya

Abstract

Background: Human infections caused by pathogens transmitted from fish are quite common. The aim of this study was to isolate enteric pathogenic bacteria from fish that might be transmitted to humans after the handling or consumption of such fish. Methodology: One hundred and twenty Nile tilapia fish harvested using various fishing methods were collected from fishermen in five fish landing beaches within Winam Gulf and disinfected externally using 70% ethyl alcohol for 2 minutes then washed three times with autoclaved distilled water. Isolation of Salmonella and Shigella species from fish samples was performed using standard bacteriological procedures. Five milliliters of each fish tissue slurry was microbiologically analyzed for any Enterobacteriaceae. Twelve Nile tilapia collected from three open-air markets were analyzed for Enterobacteriaceae comparison as controls. Identification of Salmonella by using housekeeping genes and species-specific primers was performed. Results: Among 120 Nile tilapia, 63 (52.5%) were infected with Enterobacteriaceae. Out of these, 25 (39.7%) were Shigella spp, 9 (14.3%) Salmonella typhimurium, 7 (11.1%) S. typhi, 4 (6.3%) S. enteritidis, 16 (25.4%) Escherichia coli, 1 (1.6%) Proteus spp. and Enterobacter aerogenes respectively. Ten fish collected from open-air markets yielded E. coli (50%), S. typhimurium (20%), S. paratyphi (10%) and S. typhi (20%). Conclusion: Nile tilapia within Winam Gulf are infected by human enteric pathogens. Shigella spp., Salmonella and E. coli were the most frequently isolated, an indication that the beaches may be contaminated by untreated municipal sewage, runoff, and storm-water. S. typhimurium, S. typhi and S. enteritidis were the most common Salmonella isolates.

ISOLATION OF Salmonella spp. AND OTHER MEMBERS OF Enterobacteriaceae FROM HORSE MACKEREL (Tra-churus trachurus), SOLD IN PUBLIC MARKETS OF ISTANBUL, TURKEY

“…The isolation of Proteus spp. from fish has also been reported in former studies (David et al, 2009;Lopez-Sabater et al, 1996). Yagoub, (2009, isolated Proteus spp.…”

“…in fish have been reported as 2.4%, and 10.8% respectively (Yagoub, 2009). Adededji andİbrahim, 2011, andDavid et al, 2009 have also reported contamination of shrimp and fish with E. aerogenes. The present study, the percentage of isolated Citrobacter spp.…”

Incidence and role of Salmonella in seafood safety

“…David, Wandili, Kakai, and Waindi (2009), recently described the isolation of Salmonella from fish harvested in Lake Victoria, Kenya, which supports the most productive freshwater fishery in the world. Bouchrif et al (2009) found Salmonella in 10 out of 526 seafood products analyzed in Morocco between 2002 and 2005 (Table 3).…”

Phenotypic and Genotypic Characterization of E. Coli Isolated From Fish and Human

“…E. coli isolated from Oreochromis niloticus with an incidence of (17.5%) as shown in (Table 3).These results partial agree with Saqr et al (2016) reporting incidences (18.3%). Higher incidences of E.coli were recovered by Amr et al (2012), David et al (2009), Galal et al (2013)and Gupta et al (2013) who reported incidences of E. coli 50%, 57.1%,29.34% and 36% respectively. But Atwa (2017) isolated E. coli from skin, muscle, intestine and liver with incidences 25, 22.5, 25 and 35% respectively.…”