Presence of Extended Spectrum Beta Lactamase, Virulence Genes and Resistance Determinants in Biofilm Forming Klebsiella pneumoniae Isolated from Food Sources: A Potent Risk to the Consumers

Abstract

Foodborne diseases and infection caused by associated pathogens is a public health concern. Majority of the investigations focus on common foodborne pathogens like Vibrio parahaemolyticus, Escherichia coli, Listeria monocytogenes, Shigella, Salmonella and Staphylococcus aureus. Limited knowledge has been accounted on Klebsiella pneumoniae. Presence of multidrug-resistant K. pneumoniae in the food supply is disturbing. Hence, this study assessed the presence of K. pneumoniae isolates from food samples (fresh vegetables and chicken), ascertained the presence of drug-resistant phenotypes, extended spectrum beta lactamase production, antibiotic resistance determinants, genes associated with virulence and their ability to form biofilm. Resistance towards ceftazidime and tetracycline was noted among all the isolates in the study, while they exhibited sensitivity to chloramphenicol and co-trimoxazole. All the isolates were potent ESBL producers carrying at least one ESBL encoding genes. Plasmid mediated quinolone resistance gene was detected in one isolate each from onion and chicken respectively. The isolates marked the absence of tetracycline and chloramphenicol resistance genes. Multiple virulence genes (ureA, khe, fimH, mrkD, wabG, uge and elt) were possessed by each of the isolates. K. pneumoniae from chicken and cucumber were moderate biofilm formers and those from tomato exhibited weak biofilm formation. Increased expression of the mrkA gene and reduction in the expression of the biofilm forming gene fimH gene was observed among the biofilm formers. One of the moderate and non-biofilm formers exhibited increased mrkD gene expression. The results from our study stipulate, that raw vegetables and meat serve as dormant source of drug-resistant and virulent K. pneumoniae.