Comparison of sample preparation for the isolation of Listeria species in naturally contaminated catfish and tilapia samples
Titik Budiati, Gulam Rusul, Wan Nadiah Wan-Abdullah, Yahya Mat Arip, Rosma Ahmad.
In this study, two preparation sample (pelleted and non-pelleted) and two pre-enrichment (with and without preenrichment in Half Frazer Broth) were assessed on their efficacy to isolate Listeria sp. from naturally contaminated catfish and tilapia samples. A total of 108 samples (32 catfish intestines, 32 tilapia intestines, and 44 water samples) were examined for the presence of Listeria sp. Out of 16 Listeria sp. were observed on pelleted sample and 5 Listeria sp. were observed on non-pelleted sample. All samples were preceded without pre-enrichment. Nineteen (19) isolates were observed on pelleted sample 17 on non- pelleted sample. Those were combined with pre-enrichment. The study revealed that, the isolation of Listeria sp. by pelleting the sample in the combination with pre-enrichment from naturally contaminated catfish, tilapia and water samples were relatively higher than their opponents. By improving the efficacy of isolating Listeria sp. is beneficial for reporting the presence of these pathogenic bacteria due to public health purposes.
Key words: Catfish, Isolation method, Listeria, Pelleted, Tilapia