Comparison of sample preparation for the isolation of Listeria species in naturally contaminated catfish and tilapia samples

Abstract

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.

Inhibition ofListeria monocytogenesby a formulation of selected dairy starter cultures and probiotics in anin vitromodel

“…Listeriosis, caused by Listeria monocytogenes, is a foodborne infection of public health concern due to its clinical severity and high fatality (Budiati et al 2013). In the US in 2016, multistate outbreaks of listeriosis were linked to frozen vegetables, raw milk and packaged salads (https://www.cdc.gov/listeria/outbreaks/).…”