Occurrence of Salmonella and Shigella in edible frogs (Hoplobatrachus spp) from Hanwa Frog market Zaria, Nigeria

Abstract

Frogs have been associated with bacterial infection among those who handle them resulting in symptoms such as diarrhoea, abdominal cramps, fever and vomiting. Frogs are a rich source of proteins and they are considered a delicacy by some in Nigeria. Considering the high demand for edible frogs, it is important to determine the occurrence of Salmonella and Shigella organisms from edible frogs (Hoplobatrachus spp). Edible frogs (n=202) were collected from February to July, 2016, from the Hanwa frog market, Zaria, Kaduna State. The intestinal contents of each sampled frog were scraped into the selenite broth bottles and cultured on Deoxycholate Citrate Agar for enrichment and isolation respectively. Biochemical test and sugar fermentation tests were carried out on the suspected isolates. Overall, twenty seven 27(13.37%) of the processed samples were suggestive of Shigella, while 22(10.9%) were suspect Salmonella organisms. There was no significant association between sex of the frogs and the isolation of Shigella and Salmonella organisms, despite the high occurrence of Shigella organism (14.17%) in the males. Source wise the occurrence of Salmonella in frogs was high in Tudun Wada (20%), while Katsina (8.5%) had the least. There was also no association between source and Shigella organisms. Frogs within the weight range of 175-224g had the highest occurrence rate for Shigella isolation, while frogs of 73-125g weight range had the highest occurrence rate for Salmonella isolation. This study shows the presence of Shigella and Salmonella organisms in the intestinal contents of frogs. Therefore the unhygienic and unsanitary environment, handling and processing of frogs is of great public health concern and as such measures are to be put together to ensure safety and wholesomeness of the frog meat been sold for human consumption.

Keywords: Edible, Frog, Safety, Salmonella , Shigella, Zaria