Virulence and Antibiotic Resistance Characteristics of Vibrio Isolates From Rustic Environmental Freshwaters
Oyama Gxalo, Tennison O. Digban, Bright E. Igere, Ola A. Olapade, Anthony I. Okoh, Uchechukwu U. Nwodo
Frontiers in Cellular and Infection Microbiology
Abstract
The study investigated the occurrence of antimicrobial resistance genes and virulence determinants in <i>Vibrio</i> species recovered from different freshwater sheds in rustic milieu. A total of 118 <i>Vibrio</i> isolates comprising <i>Vibrio fluvialis</i> (n=41), <i>Vibrio mimicus</i> (n=40) and <i>V. vulnificus</i> (n=37) was identified by amplification of <i>ToxR</i>, <i>vmh</i> and <i>hsp60</i> genes. The amplification of virulence genes indicated that <i>V</i>. <i>mimicus</i> (<i>toxR</i>, <i>zot</i>, <i>ctx</i>, <i>VPI</i>, and <i>ompU</i>) genes were detected in 12.5%, 32.5%, 45%, 37.5% and 10% respectively. <i>V</i>. <i>fluvialis</i> genes (<i>stn</i>, <i>hupO</i> and <i>vfh</i>) were harboured in 48.8%, 14.6% and 19.5% isolates congruently. The other virulence genes that include <i>vcgC</i> and <i>vcgE</i> were observed in 63.1% and 29% of isolates belonging to <i>V</i>. <i>vulnificus</i>. With the exceptions of imipenem, meropenem and ciprofloxacin, most isolates exhibited more than 50% resistance to antibiotics. The antimicrobial resistance was more prevalent for polymyxin B (100%), azithromycin (100%) and least in ciprofloxacin (16.1%). Multiple antibiotic resistance index range was 0.3 and 0.8 with most isolates showing MARI of 0.8. The <i>bla</i>TEM, AmpC, <i>bla</i>GES, <i>bla</i>IMP, <i>bla</i>OXA-48 and <i>bla</i>KPC genes were detected in 53.3%, 42%, 29.6%, 16.6%, 15%, 11.3% and 5.6% of the isolates. Non-beta lactamases such as streptomycin resistance (<i>aadA</i> and <i>strA</i>), gentamicin resistance (<i>aphA1</i>) and quinolone resistance gene (<i>qnrVC</i>) were found in 5.2%, 44.3%, 26% and 2.8%. Chloramphenicol resistance genes (<i>cmlA1</i> and <i>catII</i>) were found in 5.2% and 44.3% among the isolates. Our findings reveal the presence of antimicrobial resistance genes and virulent <i>Vibrio</i> species in aquatic environment which can have potential risk to human and animal's health.