Antimicrobial-resistant Salmonella spp. isolated from retail farmed shrimp in Kuala Lumpur

Abstract

Antimicrobial resistant Salmonella is recognized as a potential food safety threat and its prevalence in farmed shrimps is very concerning. However, information about antimicrobial resistant Salmonella in retail farmed shrimps in Malaysia is very limited. Therefore, this study was aimed at determining the level of Salmonella contamination of farmed shrimps at selected retails in Kuala Lumpur and antibiotic resistance pattern of Salmonella isolated from retail farmed shrimps. Farmed shrimp samples were collected from selected hypermarkets and indoor markets. Salmonella was detected by conventional methods. All presumptive colonies of Salmonella were subjected to antimicrobial susceptibility test. A high rate of Salmonella contamination was detected (n = 9, 60%) with an estimated Salmonella load ranging between 0 and >800 x 108 cfu/ml. All isolates (100%) were resistant to at least one antimicrobial agent, and 17 isolates (94.4%) were multidrug-resistant. 2 isolates (11.1%) were resistant to all eight types of antimicrobial agents. High rates of resistance were observed for erythromycin (100%), doxycycline (77.8%), tetracycline (72.2%), nalidixic acid (61.1%), ampicillin (55.6%) and chloramphenicol (44.4%). Findings from the present study provide insight on antibiotic resistant Salmonella contamination in retail farmed shrimps and suggest its potential food safety risk to the public. These data are valuable to warrant further investigation of risk management and public health strategies.