Abstract

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Periwinkles (Littorina littorea) and clams (Mercenaria mercenaria) are vital components of aquatic ecosystems, each harbouring diverse bacterial communities including potential pathogens. This study investigated the bacteriological composition and antibiotic sensitivity profiles of periwinkles and clams sampled from different markets in Ondo and Lagos States, Nigeria. The load and array of bacteria in the samples were determined using standard microbiological technique. The disc diffusion method was used to determine the antibiotic sensitivity pattern of the bacterial isolates. The molecular identities of antibiotic resistant bacterial isolates were also determined. Results showed that the bacterial counts in periwinkles ranged from 1.5×103 to 5.0×103 cfu/g whereas those in clams ranged from 4.0×103 to 9.5×103 cfu/g. Bacteria belonging to the genera Escherichia, Streptococcus, and Proteus were isolated in both samples of periwinkles and crabs. Some of the bacterial isolates exhibited significant multi-antibiotic resistance and were molecularly identified as Escherichia coli and Enterococcus faecalis. The findings of this study emphasized the significance of monitoring the bacteriological safety of seafoods such as periwinkles and clams in order to mitigate the spread of antibiotic resistance and protect human health during handling and processing of the sampled seafoods.

Keywords: Bacteria, clam, multiple antibiotic resistance, periwinkle, seafoods