Prevalence of virulent resistant Salmonella enterica strains from sushi and sashimi samples in Malaysia

ABSTRACT

Salmonella enterica is one of the leading causes of human foodborne infections. The objectives of this study are to investigate S. enterica prevalence in sushi and sashimi in Malaysia, to determine the presence of virulence genes and the antimicrobial resistance profiles of isolated S. enterica. In the 200 samples tested, 16% were positive for S. enterica. Sixty-six percent of the S. enterica isolates harboured at least one virulence gene and the most common virulence gene was sifA (37.5%). Antibiotic susceptibility testing showed 65.6% (21/32) of the isolates to be resistant to at least one antibiotic tested, with sulfamethoxazole resistance as the most common (50%). Resistance to the drugs-of-choice (fluoroquinolones and third-generation cephalosporin) for severe salmonellosis were also detected – ceftriaxone (25%), ceftazidime (28.1%) and ciprofloxacin (9.4%). Two isolates (9.5%) were resistant to all antibiotic tested while 12 isolates (37.5%) exhibited multi-drug resistance (MDR) with 10 different MDR profiles. Most of the isolates presented MDR profilesAP, AUG, FOX, NA (penicillins, beta-lactams, cephems and quinolone) with or without the addition of other drugs. In conclusion, the high rate of S. enterica prevalence in the sampled sushi and sashimi warrants increased safety measures for sushi and sashimi preparation.