Characterisation and Bacteriophage Sensitivity of Enterococci Isolated from Traditional Fermented Dairy Product

Abstract

Aims: The study aimed to detect and classify Enterococci isolates from Thayir, a traditional fermented dairy product. Study Design: A statistically significant number of Thayir samples were collected from across the study area to isolate and characterise Enterococci. Place and Duration of Study: The study took place in Wayanad District of Kerala, India in 2022-2023. Methodology: The Thayir samples were aseptically collected and bacteriologically cultured to detect enterococci. The isolates obtained were tested for the ability to form biofilms and hydrolyse gelatin. The antibiotic sensitivity pattern was studied using disk diffusion assay. A simple Kmeans clustering algorithm was applied to group the isolates.  Phage-sensitive and resistant isolates were identified among the safer isolates.  Results: Eight isolates were obtained. None of the isolates hydrolysed gelatin, but four produced biofilm. Antibiogram revealed increased sensitivity to nitrofurantoin, but most isolates were sensitive to antimicrobials. Clustering analysis revealed a set of three safer isolates, of which one was sensitive to the phage EFΦ91. Conclusion: The study revealed the presence of Enterococcus fecalis and Enterococcus faecium in thayir samples. Analyses revealed that the isolates were diverse and continued monitoring for antimicrobial resistance against Enterococci in food samples is necessary.