ABSTRACT
The frequency of antibiotic resistance among Salmonella enterica serovar Typhimurium has increased due to the transfer of multiple resistance factors. We detected the 13 antibiotic resistance genes by multiplex-PCR and compared with the results of phage typing and antibiotic disk diffusion for 49 S. typhimurium isolated from food-poisoning outbreaks in Seoul from 1999 to 2002. Resistance genes for tetracycline, streptomycin, ampicillin, sulfonamide, amino-glycoside-modifying enzyme, chloramphenicol, kanamycin, and trimethoprim were detected in 67.3%, 57.1%, 26.5%, 8.1%, 8.1%, 5%, 2.0%, and 0% of isolates, respectively. Overall 28 isolates (57.1%) possessed two or more antibiotic resistance genes. Class 1 integron carrying multidrug resistace genes, ant(3")-IaB, blaPSE, qacE delta1/sul, and tet G were amplified especially in only DT104 isolates. Among the related resistance genes for same antibiotics, strA and strB for streptomycin resistance were simultaneously detected but tetA and tetB for tetracycline were sporadically detected. DT 104 isolates contained only aadA2 and tetG.
Subject(s)
Humans , Ampicillin , Anti-Bacterial Agents , Bacteriophage Typing , Chloramphenicol , Diffusion , Disease Outbreaks , Drug Resistance, Microbial , Integrons , Kanamycin , R Factors , Salmonella enterica , Salmonella , Seoul , Streptomycin , Tetracycline , TrimethoprimABSTRACT
The incidence and distribution of the human rotavirus G types (VP7 associated: G1~G4) and P types (VP4 associated: P[4], P[6], P[8], P[10]) were determined from 89 rotavirus strains isolated from diarrhea patients between 2001 and 2002 using reverse transcription and multiplex polymerase chain reaction. G types were identified from 83 (95.5%) and P types were from 82 (92.1%) strains. The predominant genotypes were P[4]G2 (28.1%) and P[6]G4 (27%) with much lower incidence of genotypes P[10]G1 (1.1%) and P[10]G3 (1.1%). P[9] type was not detected. A significant genotypic shift was observed that P[4] was the most prevalent genotype that accounted for 75% during the spring season of 2001, coinfection with P[4] and P[6] for 17.5%. P[6] increased gradually to account for 53% of the strains analysed in the following 2002 spring season. Mixed G types revealing coinfections G2/G3 and G3/G4 were found at low frequency (2.2%).