Contamination level and characterization of Staphyloccocus aureus associated with ready-to-eat foods, food handlers, and environmental factors

Aims@#Although several major food poisoning outbreaks caused by Staphylococcus aureus have been reported, monitoring of this pathogen is often neglected. The objectives of this study were to assess the contamination level of S. aureus and characterize the S. aureus isolated in ready-to-eat (RTE), food handlers, food contact surfaces, and table cleaning cloths (TCC). @*Methodology and results@#A total of 150 RTE foods, 59 food contact surfaces (FCS) and 34 table cleaning cloths (TCC) from food premises were examined. The contamination level of S. aureus in RTE foods was at acceptable level. However, more than 10% of the FCS and TCC were contaminated with high levels of S. aureus (>1.0 Log CFU/cm2, >2.7 Log CFU/piece). Eighty-one isolated S. aureus including those isolated from hands of food handlers were further characterized by antimicrobial susceptibility testing, virulotyping and PFGE. Out of 81 isolates, only three were multidrug resistant. More than 96% (n = 78) of the S. aureus harboured at least one virulence gene. Almost half of the isolates carried at least one staphylococcal enterotoxin in which SEC was the most common enterotoxin detected. @*Conclusion, significance and impact of study@#The PFGE analysis showed that the S. aureus could be disseminated via the FCS, TCC and the hands of food handlers. Therefore, this study reiterates the importance of proper hand washing, sanitation of FCS and TCC, as well as continuous monitoring on S. aureus in food and the food handlers.

Screening and characterisation of two Pseudomonas aeruginosa from aquaculture and water environment

Aims@#Pseudomonas has been associated with diseases occurring in people with weakened or compromised immune system after exposure to contaminated water. The diseases are commonly treated with antibiotics. However, the bacteria had developed resistances to commonly used antibiotics making treatment a difficult task. Therefore, the continuous surveillance of susceptibility of Pseudomonas especially for the human pathogen P. aeruginosa to commonly clinical and aquaculture farming used antibiotics is important to ensure that serious infections remain susceptible to those antibiotics.@*Methodology and results@#In this study, the bacteria were screened from water, sediment and fish from rivers and aquaculture farms around Kuching, Sarawak. A total number of 38 presumptive P. aeruginosa were isolated using CHROMagar TM Pseudomonas and subjected to a series of biochemical tests. Out of all the isolates tested, only two isolates designated as AS-R10(S) and BK2-OLT2(S) fulfilled the biochemical characteristics of P. aeruginosa. 16S rRNA gene sequencing further confirmed these two isolates as P. aeruginosa based on their 100% similarity with P. aeruginosa strain GD1 and P. aeruginosa strain PA1201 in NCBI database. These two isolates were tested for their susceptibilities against nine common antibiotics used in both clinical and aquaculture farming nowadays: imipenem, piperacillin, meropenem, amikacin, gentamicin, ciprofloxacin, ceftazidime, tobramycin and norfloxacin according to CLSI standard using disk diffusion method.@*Conclusion, significance and impact of study@#The two isolates exhibited total susceptibility to all the antibiotics analysed, suggesting the effectiveness of the antimicrobial agents towards P. aeruginosa isolated from aquaculture and water environment in the study area.