From March 2000 to September 2001, 608 samples of retail meat (136 pork, 70 beef, 202 chicken, and 200 ducks) and 110 samples of retail shrimp from six provinces of the Mekong Delta in Vietnam were collected individually and examined for the prevalence of Salmonella. Of the 718 samples examined, 243 (33.8%) were Salmonella positive. Salmonella was isolated from 69.9% of the pork samples, 48.6% of the beef samples, 21.0% of the chicken meat samples, 22.3% of the duck meat samples, and 24.5% of the shrimp samples. From 261 Salmonella isolates, 24 different serovars were identified. The predominant serovars of the isolates were Salmonella Derby, Salmonella Weltevreden, and Salmonella London in pork; Salmonella Weltevreden, Salmonella London, and Salmonella Dessau in beef; Salmonella Emek, Salmonella Typhimurium, and Salmonella Dessau in chicken meat; Salmonella Lexington, Salmonella Derby, and Salmonella Dessau in duck meat; and Salmonella Weltevreden, Salmonella Tennessee, and Salmonella Dessau in shrimps. Salmonella Bovismorbificans, Salmonella Derby, Salmonella Dessau, and Salmonella Weltevreden were the most common serovars in all the samples examined. These results indicate a high rate of contamination by Salmonella in retail meats and shrimps in the Mekong Delta, Vietnam.

In order to determine the prevalence of Salmonella spp. in domestic animals in 6 provinces of the Mekong Delta, Vietnam, 1,098 fecal or intestinal content samples from pigs, chickens, and ducks were examined in the period from July to October, 2000. Salmonella spp. were isolated from 78 (7.1%) of the total samples, which included 23 (5.2%) of 439 pigs, 24 (7.9%) of 302 chickens, and 31 (8.7%) of 357 ducks. From those samples, 80 Salmonella strains were isolated and 25 serovars were identified. The predominant serovars were S. Javiana, S. Derby, and S. Weltevreden. S. Javiana and S. Weltevreden were detected together in pigs, chickens, and ducks. These results indicate that the serovars of Salmonella are widely distributed in domestic animals in the Mekong Delta, Vietnam.

ABSTRACT. A total of 230 Salmonella isolates representing 33 serotypes originated from food (pork, beef, chicken meat, duck meat, and shrimp), domestic animals (pig, chicken, and duck), and human (children with diarrhea) in the Mekong Delta, Vietnam were examined for the antimicrobial resistance to 10 antibiotics. Of the 230 Salmonella isolates examined, 49 (21.3%) showed antimicrobial resistance. Thirty-eight isolates (16.5%) were resistant to oxytetracycline, 26 (11.3%) to chloramphenicol, 17 (7.4%) to nalidixic acid, 16 (7.0%) to streptomycin, 5 (2.2%) to kanamycin, and 4 (1.7%) to ampicillin. No isolate showed resistance to gentamicin, cefazolin, ceftriaxone, and ciprofloxacin. Among the resistant isolates, nineteen isolates were resistant to one antimicrobial agent, 10 to two, 15 to three, 3 to four, and 2 to five antimicrobial agents. The resistance rate of Salmonella isolates from the Mekong Delta, Vietnam to these antimicrobial agents seems to be relatively lower than the results of developed countries and even those of the neighboring countries.