1.Prevalence of virulent resistant Salmonella enterica strains from sushi and sashimi samples in Malaysia
Suat Moi Puah ; Kek Heng Chua ; Jin Ai Mary Anne Tan
Tropical Biomedicine 2016;33(3):476-485
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.
2.Prevalence of Staphylococcus aureus and Salmonella enterica in ready-to-eat sushi and sashimi
Suat Moi Puah ; Kek Heng Chua ; Jin Ai Mary Anne Tan
Tropical Biomedicine 2017;34(1):45-51
Abstract. Staphylococcus aureus food poisoning and Salmonellosis outbreaks have been
associated with two popular ready-to-eat items: sushi and sashimi. Thus this study aims to
determine the prevalence of S. aureus and S. enterica in sushi and sashimi in Malaysia. Sushi
(149) and sashimi (51) were collected from 14 retail outlets comprising supermarkets,
hypermarkets, restaurants and open-air night markets. Bacterial isolation was carried out
using Baird-Parker and CHROMagar Salmonella Plus selective media. The food pathogens
isolated from microbiological media were then confirmed by molecular analysis. The results
confirmed an overall S. aureus and S. enterica contamination of 42% (84/200) in the sushi and
sashimi samples. Regarding prevalence of the individual pathogens involved, S. aureus was
detected in 26% (52/200) and S. enterica in 16% (32/200) of the contaminated samples. This
study demonstrates a high occurrence rate of S. aureus and S. enterica in sushi and sashimi
foods in Malaysia, and warrants the necessity to monitor the microbiological process of RTE
foods to ensure food safety for consumers.