Recovery of Salmonella using a combination of selective enrichment media and antimicrobial resistance of isolates in meat in Thailand.

From November 2004 to March 2005, 50 samples (chicken, pork and beef) of registered meat and non-registered meat were purchased from supermarkets and retail markets located in Bangkok, Thailand. Each sample was evaluated for Salmonella spp by a conventional method using combination of selective enrichment media (RV+MSRV) and compared with selective enrichment medium alone (DIASALM). Our study revealed the performance of RV+MSRV for the detection of Salmonella spp was significantly better than those of DIASALM alone since the recovery of Salmonella spp in both groups of meat was high using RV+MSRV, particularly in the registered meat. In addition, the recovery of serovars in registered meat was significantly higher than those in non-registered meat. Antimicrobial resistance of 62 Salmonella isolates in both groups of meat was determined for 10 antimicrobial drugs using the disk diffusion method. The results show that 100% of isolates from both groups were susceptible to amoxicillin/clavulanic acid, ciprofloxacin, cefotaxime and norfloxacin and 50-60% of isolates from both groups were resistant to tetracycline, streptomycin and ampicillin. Sixty percent of Salmonella isolates from meat showed multiresistance antimicrobial patterns.