Titik Budiati, Gulam Rusul, Wan Nadiah Wan-Abdullah, Yahya Mat Arip, Rosma Ahmad
Microbiology of Microbiology
The aim of this study was to modify the isolation methods of Aeromonas sp., Salmonella spp., and Listeria sp. in catfish (Clarias gariepinus) and tilapia (Tilapia mossambica) obtained from wet markets and ponds in Malaysia by pelleting the sample. A total of 108 samples (32 catfish intestines, 32 tilapia intestines, and 44 water samples) were obtained from nine wet markets and eight ponds. The modified method was employed by pelleting the samples and followed by either implementing pre-enrichment or without pre-enrichment on the isolation of Salmonella and Listeria spp. The modified method (by pelleting the sample in combination with pre-enrichment) was the most efficient for Salmonella and Listeria isolation. The sensitivity of the modified Salmonella isolation method was 0.53 and 0.73 for fish and water samples, respectively. The sensitivity of the modified Listeria method was 1 and 0.92 for fish and water samples, respectively. However, the sensitivity of the method by pelleting the sample was similar to those of non-pelleting the sample on Aeromonas isolation. Five species of Aeromonas spp., seven serovars of Salmonella sp., and four species of Listeria sp. were observed in catfish, tilapia and water samples. Overall, by pelleting the sample offered the beneficial to isolate Aeromonas spp., Salmonella sp. and Listeria spp. in catfish, tilapia and water.