ABSTRACT. During the period from 1993 to 1996, a total of 27,497 Salmonella isolates from humans, chicken meat, ready-to-eat Thai foods and shrimps were serotyped to know the predominant serovars of Salmonella in humans and foods in Thailand. Seventy-two and 81 serovars of Salmonella were identified in human and food samples, respectively. The significance of foods as a vehicle for human salmonellosis was discussed from an epidemiological viewpoint.-KEY WORDS: Salmonella, Salmonella Enteritidis, Salmonella Weltevreden.J. Vet. Med. Sci. 60 (7): [877][878][879][880] 1998 All strains were identified and serotyped according to the Kauffmann technique [8]. In brief, DHL agar (Difco) and XLD agar (Difco) were used as isolation media. Then, suspected Salmonella isolates were streaked on Endo agar plates, which were incubated at 37°C for 18 hr, then the specific colonies were selected for biochemical tests, as described by Ewing [5]. After biochemical tests, the colonies were subjected to serotyping with antisera made in our laboratory according to the Gard technique [6]. O antigen was determined by slide agglutination with O polyvalent and O factor antisera. Flagella (H) antigen was determined by using the bacteria grown on swarm agar (0.7% agar) at 37°C for 18 hr and H polyvalent and factor antisera. The serovar was identified according to both the biochemical and serological data.Of Salmonella strains, 72 serovars were detected in humans, and the details of 13 predominant serovars are shown in Table 1. In order of predominance, the first in the human stools was S. Weltevreden in 1993Weltevreden in , 1995Weltevreden in , and 1996 and S. Derby in 1994; the second was S. Derby in 1993, S. Weltevreden in 1994 and S. Enteritidis in 1995 the third, S. Enteritidis in 1993 S. Derby in 1995 and S. Typhimurium in 1996. In blood and such other specimens as pus, urine, and cerebrospinal fluid, S. Enteritidis was the most predominant during the 4-year survey, and the second was S. Choleraesuis.Salmonella strains comprising 81 serovars were detected in frozen chicken meat, ready-to-eat Thai foods and frozen shrimps ( Table 2). The most common serovar in frozen chicken meat was S. Enteritidis, which accounted for

To determine the phage types (PT) of Salmonella enteritidis found in Thailand and to clarify the potential for human infection by S. enteritidis in broiler chicken meat, human and poultry isolates taken from Thailand between 1990 and 1997 were phage typed and analyzed by pulsed-field gel electrophoresis (PFGE). Ten different PT were found among the 302 isolates phage typed, with PT 4 being the most frequent in human (73.9%) and poultry (76.2%) isolates, followed by PT 1 (8.0%), 8 (3.6%), and 7a (2.2%) in human isolates and by PT 7a (4.9%), 1 (3.7%), and 12 (2.4%) in poultry isolates. Of the 53 isolates analyzed by PFGE, 45 showed an indistinguishable pattern (pattern A) byBlnI-digested PFGE and the other 8 isolates showed a very similar pattern that differed by only a few bands. These results indicate the spread of a genetically identical clone ofS. enteritidis in humans and poultry in Thailand.

ABSTRACT. This is the first report regarding isolation of Salmonella from cecum samples of buffaloes and pigs and characterization of the isolates in Laos. The organisms were isolated from 8% (4/50) of buffaloes and 76% (37/49) of pigs. In buffaloes, 3 animals harbored serotype 9,12: -:1,5, and 1 animal harbored both S. Derby and S. Javiana. In pigs, the most predominant serotypes were S. Derby (51%) followed by S. Anatum (45%), S. Weltevreden (15%) and S. Stanley (5%). The buffalo isolates were susceptible to the antimicrobials tested, whereas the pig isolates showed 10 resistance patterns to 1-5 antibiotics. Of the 59 pig isolates, the resistance rates to tetracycline, streptomycin, ampicillin, sulfamethoxazole-trimethoprim, chloramphenicol, amoxicillin-clavulanic acid and nalidixic acid were 24%, 22%, 14%, 5%, 2%, 2% and 2%, respectively. The results suggest that pigs and buffaloes harbor Salmonella, with a higher prevalence especially in pigs, and all the isolates showed sensitivity to cefotaxime, norfloxacin and ciprofloxacin.

The present study was performed to assess the prevalence of Salmonella in chickens in Thailand. In 1997, 22 serovars of Salmonella were isolated from 72 of 100 chicken meat samples purchased from 10 retail markets in Bangkok and 20 of 200 chicken meat samples from one slaughterhouse for export and 19 of 285 chicken feces obtained from three farms located in the east region of Thailand. The most predominant serovar was S. Enteritidis, which was isolated from 28% of the retail chicken meat, 4.5% of the chicken meat from slaughterhouse, and 6.6% of chickens feces samples examined.