Antibiotic Resistance in Salmonella Isolated from Ho Chi Minh City (Vietnam) and Difference of Sulfonamide Resistance Gene Existence in Serovars

Abstract

In this study, a total of 228 raw meat samples (pork: 76, beef: 76, chicken: 76) and 301 raw seafood samples (fish: 199, shrimp: 67, squid: 35) were collected randomly at traditional markets in Ho Chi Minh City (Vietnam). In meat, the ratio of Salmonella spp. was 70.61% (161/228). Among the contaminated meat samples, pork was infected with a ratio of 90.79 % (69/76) while the contamination ratios in beef and chicken were 43.42% (33/76) and 77.63% (59/76), respectively. Salmonella contamination was detected in fish (40.20%), shrimp (7.46%) and squid (17.14%). Because of sulfonamide group is used in Salmonella treatment, the study focused on sulfonamide resistance. In fresh seafood comparison, there were 32.56%, 40% and 10% Salmonella showing resistance to sulfamethoxazol in fish, squid and shrimp, respectively. In fresh meat comparison, there were 31.58%, 16.67% and 55.56% Salmonella showing resistance to sulfamethoxazol in pork, beef and chicken, respectively. Interestingly, there were 21 serovars including 19 identified serovars including S. Kentucky (8), S. Agona (2), S. Infanis (4), S. Saintpaul (1), S. Indiana (1), S. Braenderup (1), S. Potsman (2) and 2 unidentified serovars showing different phenotype to this antibiotic. Among the 21 serovars, only 23.81% strains carried both genes (sul1, sul2). For the sul1 gene, 61.9% strains were presented while sul2 occupied at a lower rate than sul1 with the rate of 52.38%. The study is very interesting and useful to go more functional analysis in sulfonamide resistance.

Keywords

• salmonella
• sulfonamide resistance
• sul1 and sul2 genes
• multiplex polymerase chain reaction (m-pcr)
• serovars
• raw meat
• seafood