ABSTRACT
The multi-antimicrobial resistance gene cluster and its derivatives have been detected in Salmonella genomic island 1 (SGI1), which has been identified in the Salmonella enterica serovar Typhimurium, phage types DT104, DT12, DT120, and U302, as well as other Salmonella serovars, including Agona, Paratyphi B, Albany, Meleagridis, Newport, Cerro, Derby, Dusseldorf, Infantis, Kiambu, and Emek. We acquired 53 Salmonella Typhimurium DT104 isolates from diarrheal patients in Korea. From these isolates, we identified a novel antimicrobial resistance gene cluster as an additional gene cassette in SGI1 from a multi-antimicrobial resistant isolate. The minimum inhibitory concentration for this isolate against ampicillin and chloramphenicol was two to four times higher than those for other multi-antimicrobial-resistant Salmonella Typhimurium DT104 isolates. The new antimicrobial resistance gene cluster detected in this isolate consisted of bla(PSE-1), sul1 Delta, floR, and tetR, in that order. The order of this gene cluster was shuffled as compared to that of the known In104 in SGI1. This report is, to the best of our knowledge, the first to identify and describe an additional shuffled antimicrobial resistance gene cluster in SGI1.
Subject(s)
Anti-Bacterial Agents/pharmacology , DNA, Bacterial/analysis , Drug Resistance, Multiple, Bacterial/genetics , Genomic Islands , Salmonella typhimurium/drug effects , Salmonella typhimurium/genetics , Bacterial Typing Techniques , Base Sequence , Blotting, Southern , Cloning, Molecular , Colony Count, Microbial , Dose-Response Relationship, Drug , Electrophoresis, Gel, Pulsed-Field , Genes, Bacterial/genetics , Genomic Islands/genetics , Humans , Microbial Sensitivity Tests , Molecular Sequence Data , Multigene Family/genetics , Salmonella Infections/drug therapy , Salmonella Infections/microbiologyABSTRACT
We analyzed 66 Salmonella Enteritidis isolates in 2002. Thirty isolates were obtained from human patients with diarrhea, and 36 were obtained from chickens. A total of ten phage types (PT) were identified in the human and chicken isolates. PT1 and PT21 were the predominant PTs in both the human (20% and 13%) and chicken (17% and 47%) isolates. Twelve pulsotypes were generated by PFGE and divided into two major groups. Most of the PFGE types were categorized into cluster group 1. Eighteen chicken isolates in cluster group 1 showed high-level genetic association (>95%) with 22 other human isolates. Additionally, six chicken isolates from cluster group 2 showed fairly high-level genetic association (>95%) with the other seven human isolates. The highest levels of genetic association in humans and chickens were seen with A5-PT21 (11 isolates), A2-PT1 (7 isolates), and B1-PT4 (6 isolates). The Pulsed-Field Gel Electrophoresis (PFGE) and phage typing provided conclusive evidence that human Salmonella infections are attributable to the consumption of contaminated chicken.
Subject(s)
Poultry Diseases/microbiology , Salmonella Infections/microbiology , Salmonella Phages/classification , Salmonella Phages/isolation & purification , Salmonella enterica/genetics , Salmonella enterica/isolation & purification , Animals , Bacteriophage Typing , Chickens , DNA, Bacterial/analysis , Electrophoresis, Gel, Pulsed-Field , Humans , Phylogeny , Salmonella Infections/virology , Salmonella enterica/classification , Salmonella enterica/virologyABSTRACT
Salmonella enterica serovar Typhimurium DT104 (Salmonella Typhimurium DT104 or DT104) has been emerging as a common pathogen for human in Korea since 1997. In order to compare the genomic relationship and to search for the dominant strains in Korea, we conducted pulsed-field gel electrophoresis (PFGE) and IS200 fingerprinting of 25 epidemiological unrelated isolates from human and animals from Korea and cattle from America. Two Salmonella Typhimurium DT104 isolates from human in Korea and all 8 isolates from American cattle had indistinguishable patterns from the PFGE and IS200 fingerprinting but multidrug-resistant Salmonella Typhimurium isolates, including DT104, from Korean animals had diverse genetic patterns. The data suggest that a dominant DT104 strain might have circulated between Korean and American cattle and that it had a high level of clonality.
