Distribution of multiple antibiotic resistant Vibrio spp across Palk Bay

Abstract

Presence of multiple antibiotic resistant microorganisms in marine systems is increasingly a focus of concern as they pose potential health risk to humans and animals. The present study reports the distribution, diversity, antibiotic resistance profile and pathogenicity of Vibriospp. in the water column of Palk Bay (PB) extending from Uchipuli along the southeast Indian coast to Thalaimannar in the northwest of Sri Lanka. Our analysis has confirmed the presence of five Vibriospp (V. cholerae, V. hollisae, V. furnissi, V. alginolyticusand V. aestuarianus) in the region with the dominance of V. cholerae, which accounted for more than 50% of the total number of isolates. V. choleraeisolates showed resistance against β-lactam, vancomycin, nitrofurantoin, gentamicin, azithromycin, oxytetracycline, tetracycline and chloramphenicol antibiotics. High levels of Escherichia coliin PB indicate the possible anthropogenic input to the prevalence of multiple antibiotic resistance. On a positive note is the absence of blaNDM-1 gene, which confers microorganism with resistance against third generation carbapenem antibiotics. Among toxicity genes tested, toxR gene was found present and ctxA absent in all the isolates. The step up multiple regression model confirmed the interaction effect, more of environmental parameters than their individual influence on the distribution of E. coliand Vibriospp. In conclusion, the present study reports the widespread distribution of multiple antibiotic resistant Vibriospp. in the water column of PB. Further studies are in progress to assess the level of antibiotic pollution in PB, and antibiotic resistance among microorganisms associated with fauna and flora of PB.