Vol. 11, Special Issue 5 (2022)

Author(s):
Narmada S, Chinta Siva Swetha, Jagadeesh Babu A, Vijaya Lakshmi S, Vinayaka Siddartha P and Madhava Rao T

Abstract:
Aeromonas hydrophila is a food borne pathogen of emerging importance. In the present investigation, a total of 200 fish samples were procured from different fish markets located in and around Tirupati, Andhra Pradesh. Out of 200 samples collected, 87 (43.5%) isolates were positive for Aeromonas spp. based on colony characteristics. On further confirmation with biochemical tests, it was found that 71 presumptive isolates were identified as Aeromonas spp., among which only four isolates (5.7%) were confirmed as Aeromonas hydrophila. Among these four presumptive isolates, only three were confirmed as Aeromonas hydrophila by PCR targeting the genus specific and species specific genes viz., 16S rRNA and gyrB gene respectively. On genotypic characterization of virulence genes, it was found that none of the isolate harboured aer virulence gene whereas act virulence gene is present in all the three Aeromonas hydrophila isolates. In antimicrobial resistance studies, all the three Aeromonas hydrophila isolates have shown different antimicrobial patterns against ampicillin–sulbactam, cefepime, ceftriaxone, gentamicin, tetracycline ciprofloxacin, co-trimoxazole and chloramphenicol by using standard disc diffusion method. The present study indicates the presence of multidrug resistance A. hydrophila isolates in fish samples which is a public health hazard and the need for continuous monitoring and surveillance of this pathogen.