Prevalence and Antimicrobial Susceptibility of Vibrio parahaemolyticus Isolated from Short Mackerels (Rastrelliger brachysoma) in Malaysia

Abstract

Numerous prevalence studies and outbreaks of <i>Vibrio parahaemolyticus</i> infection have been extensively reported in shellfish and crustaceans. Information on the quantitative detection of <i>V. parahaemolyticus</i> in finfish species is limited. In this study, short mackerels (<i>Rastrelliger brachysoma</i>) obtained from different retail marketplaces were monitored with the presence of total and pathogenic strains of <i>V. parahaemolyticus</i>. Out of 130 short mackerel samples, 116 (89.2%) were detected with the presence of total <i>V. parahaemolyticus</i> and microbial loads of total <i>V. parahaemolyticus</i> ranging from <3 to >10⁵ MPN/g. Prevalence of total <i>V. parahaemolyticus</i> was found highest in wet markets (95.2%) followed by minimarkets (89.1%) and hypermarkets (83.3%). Pathogenic <i>V. parahaemolyticus</i> strains (<i>tdh</i>+ and/or <i>trh</i>+) were detected in 16.2% (21 of 130) of short mackerel samples. The density of <i>tdh</i>+ <i>V. parahaemolyticus</i> strains were examined ranging from 3.6 to >10⁵ MPN/g and microbial loads of <i>V. parahaemolyticus</i> strains positive for both <i>tdh</i> and <i>trh</i> were found ranging from 300 to 740 MPN/g. On the other hand, antibiotic susceptibility profiles of <i>V. parahaemolyticus</i> strains isolated from short mackerels were determined through disc diffusion method in this study. Assessment of antimicrobial susceptibility profile of <i>V. parahaemolyticus</i> revealed majority of the isolates were highly susceptible to ampicillin sulbactam, meropenem, ceftazidime, and imipenem, but resistant to penicillin G and ampicillin. Two isolates (2.99%) exhibited the highest multiple antibiotic resistance (MAR) index value of 0.41 which shown resistance to 7 antibiotics. Results of the present study demonstrated that the occurrence of pathogenic <i>V. parahaemolyticus</i> strains in short mackerels and multidrug resistance of <i>V. parahaemolyticus</i> isolates could be a potential public health concerns to the consumer. Furthermore, prevalence data attained from the current study can be further used to develop a microbial risk assessment model to estimate health risks associated with the consumption of short mackerels contaminated with pathogenic <i>V. parahaemolyticus</i>.