ABSTRACT
Sequence type (ST) 33 of Shiga toxin-producing Escherichia coli (STEC) strain O91:H14 has been proposed as a potential domestic clone of STEC in Korea because of its high prevalence among human patients with mild diarrhea or asymptomatic carriers. Herein, the clonal diversity of 17 STEC O91:H14 isolates of ST33 during 2003 to 2014 was analyzed by pulsed-field gel electrophoresis, including 14 isolates from human patients and 3 from retail meats. Their virulence characteristics, acid resistance, and antimicrobial susceptibility were also determined. Our results showed that all isolates were clustered mainly into three different pulsotypes and were likely low pathogenic without antimicrobial resistance.
Subject(s)
Humans , Clone Cells , Diarrhea , Electrophoresis, Gel, Pulsed-Field , Escherichia coli , Korea , Meat , Molecular Epidemiology , Prevalence , Shiga Toxin , Shiga-Toxigenic Escherichia coli , VirulenceABSTRACT
Community-associated methicillin resistant Staphylococcus aureus (CA-MRSA) has become widespread in the community and healthcare settings, and a number of clonal lineages emerged on every country. Sequence type (ST) 80 clone of CA-MRSA was dominant in Europe and has increasingly been isolated from the Middle East but so far never found in Korea. In this study, 48 MRSA isolates recovered from ear infections were characterized by multilocus sequence typing (MLST), staphylococcal cassette chromosome mec (SCCmec) typing, staphylocoagulase (SC) genotyping, staphylococcal protein A gene (spa) typing, accessory gene regulator (agr) typing, and virulence gene profiling. Most MRSA strains belonged to three major clones: ST5-SCCmec II-SC type II (n=19, 39.6%), ST239-SCCmec III-SC type IV (n=15, 31.2%), and ST72-SCCmec IV-SC type Vb (n=11, 22.9%). Among the isolates, one strain was Panton- Valentine leukocidin (PVL)-positive ST80-SCCmec IV-SC type XIa - spa type t044-agr group III, and exfoliative toxin D-positive. This strain was susceptible to most antibiotics, but resistant to tetracycline and fusidic acid. This is the first report on the emergence of European ST80 CA-MRSA clone in Korea.
Subject(s)
Anti-Bacterial Agents , Clone Cells , Coagulase , Delivery of Health Care , Ear , Europe , Fusidic Acid , Korea , Leukocidins , Methicillin Resistance , Methicillin-Resistant Staphylococcus aureus , Middle East , Multilocus Sequence Typing , Staphylococcal Protein A , Staphylococcus aureus , Tetracycline , VirulenceABSTRACT
The molecular characteristics of methicillin-resistant Staphylococcus aureus (MRSA) isolated from neonates in a neonatal intensive care unit (NICU) were investigated by multilocus sequence typing (MLST), staphylocoagulase (SC) genotyping, staphylococcal cassette chromosome mec (SCCmec) typing, accessory gene regulator (agr) typing, and the presence of Panton-Valentine leukocidin (PVL). Among the 44 S. aureus isolates from nares in neonates between March and June 2014 at hospital in Busan, 27 (61.4%) were MRSA and 17 (38.6%) were methicillin-susceptible S. aureus (MSSA). The most prevalent clone in MRSA isolates was ST72-SC type Vb-SCCmec IV-agr I (n=26) and the remaining one was ST89-SC type I-SCCmec II-agr II. In MSSA isolates, the prevalent clone was ST121-SC type Va-agr IV (n=13), followed by ST72-SC type Vb-agr I (n=2), ST8-SC type III-agr I (n=1) and ST15-SC type X-agr II (n=1). All isolates did not possess the PVL. The data showed that the neonates in NICU carried high prevalence of ST72 MRSA and remarkably different clones with SC diversity between MRSA and MSSA isolates.