Child ; Clone Cells ; Drug Resistance, Microbial ; Electronic Health Records ; Humans ; Joints ; Korea ; Leukocidins ; Methicillin-Resistant Staphylococcus aureus ; Molecular Epidemiology ; Molecular Typing ; Polymerase Chain Reaction ; Seoul ; Skin ; Soft Tissue Infections ; Staphylococcus aureus ; Staphylococcus

PURPOSE: This study aimed to investigate the molecular epidemiology of a methicillin-resistant Staphylococcus aureus (MRSA) outbreak at a newborn nursery and neonatal intensive care unit (NICU).METHODS: During the outbreak, from August to September 2017, MRSA isolates collected from neonates and medical staff underwent genotyping and screened for virulence factors. Antibiotic susceptibilities were tested.RESULTS: During the study period, 41 neonates were admitted at the nursery (n=27) and NICU (n=14). Of these, 7 had MRSA infections (skin infection [n=6] and sepsis [n=1]) and 4 were colonized with MRSA. Associated medical staff (n=32) were screened; three were nasal MRSA carriers. Staphylococcal chromosomal cassette mec (SCCmec) type II, sequence type (ST) 89, spa type t375 was found to be the skin infection outbreak causing strain, with multi-drug resistance including low-level mupirocin resistance. SCCmec type IVa, ST 72, and a novel spa type designated t17879, was the cause of MRSA sepsis. Many different types of MRSA were colonized on the neonates; however, SCCmec type IVa, ST 72, spa type t664 was colonized in both neonates and a NICU nurse. All MRSA isolates from colonized infants were positive for the Panton-Valentine leukocidin (PVL) toxin gene.CONCLUSIONS: The strain causing an outbreak of skin infections had multi-drug resistance. Also, MRSA colonized in the neonates were found to carry the PVL toxin gene. Because different strains are present during an outbreak, molecular epidemiologic studies are important to identify the outbreak strain and colonized strains which aid in effective control and prevention of future MRSA outbreaks.
Colon ; Disease Outbreaks ; Drug Resistance, Multiple ; Epidemiologic Studies ; Humans ; Infant ; Infant, Newborn ; Intensive Care, Neonatal ; Leukocidins ; Medical Staff ; Methicillin Resistance ; Methicillin-Resistant Staphylococcus aureus ; Molecular Epidemiology ; Mupirocin ; Nurseries ; Sepsis ; Skin ; Virulence Factors

OBJECTIVES: Staphylococcus aureus is a nosocomial pathogen that provides a major challenge in the healthcare environment, especially in burns units where patients are particularly susceptible to infections. In this study, we sought to determine molecular types of S. aureus isolates collected from burns patients, based on staphylococcal protein A and coagulase gene polymorphisms. METHODS: Antibiotic susceptibility testing of 89 S. aureus strains isolated from burn wounds of patients was assessed using the Kirby-Bauer disk diffusion method. Strains were characterized by spa typing, coa typing, and resistance and toxin gene profiling. RESULTS: A total of 12 different spa types were identified with the majority being t790 (18%). Panton-Valentine leucocidin encoding genes were identified in spa types t044 (5.6%), t852 (2.2%) and t008 (2.2%). The most commonly detected antibiotic resistance gene was ant (4′)-Ia (60.7%). Ten different coa types were detected and the majority of the tested isolates belonged to coa III (47.2%). All the high-level mupirocin-resistant and low-level mupirocin resistant strains belonged to coa type III. CONCLUSION: The present study illustrated that despite the high frequency of coa III and spa t790 types, the genetic background of S. aureus strains in Iranian burns patients was diverse. The findings obtained are valuable in creating awareness of S. aureus infections within burns units.
Ants ; Burns ; Coagulase ; Delivery of Health Care ; Diffusion ; Drug Resistance, Microbial ; Genetic Background ; Humans ; Leukocidins ; Methicillin Resistance ; Methicillin ; Methicillin-Resistant Staphylococcus aureus ; Methods ; Microbial Sensitivity Tests ; Mupirocin ; Staphylococcal Protein A ; Staphylococcus aureus ; Staphylococcus ; Wounds and Injuries

Staphylococcus aureus is a well-recognized human pathogen that causes a wide range of infections as a result of its extensive virulence factors. One of these factors is Panton-Valentine leukocidin (PVL), a potent pore-forming cytotoxin that has been linked to invasive S. aureus infections. PVL is one of the important virulence factors for S. aureus and has been largely recognized as one of the markers for community-acquired methicillin-resistant S. aureus. However, the presence of PVL in methicillin-susceptible S. aureus infections is not widely reported in the literature. Thrombotic sequelae of S. aureus infections associated with PVL expression are uncommon in children. We hereby report two children with thrombotic complications associated with PVL-producing methicillin-susceptible S. aureus. Both patients responded well to antibiotic and anticoagulant therapies, and survived without any long-term sequelae.
Child ; Humans ; Leukocidins ; Methicillin Resistance ; Staphylococcus aureus ; Staphylococcus ; Virulence Factors

Staphylococcus aureus is now a major community-acquired pathogen worldwide, notably associated with skin and soft tissue infections. Staphylococci are present in the form of colonizers or environmental contaminants at home and increase the risk of recurrent infection. We are describing recurrent familial furunculosis caused by Panton-Valentine Leukocidin-positive methicillin susceptible S. aureus ST1 in Korea. An infant, his father and mother had furunculosis due to methicillin-sensitive S. aureus (MSSA) infection with identical susceptibility patterns. ST1 accounted for all 3 isolates and they were confirmed of having agr group I. Both sec and seh were detected in all isolates using polymerase chain reaction (PCR) assays, and all isolates contained Panton-Valentine leukocidin (PVL) genes. Risk factors for the household spread of S. aureus include skin conditions and close physical contact among household members. The relationship between S. aureus colonization of household contacts and the occurrence of S. aureus infection should be studied into more detail.
Colon ; Family Characteristics ; Fathers ; Furunculosis ; Humans ; Infant ; Korea ; Leukocidins ; Methicillin ; Mothers ; Polymerase Chain Reaction ; Risk Factors ; Skin ; Soft Tissue Infections ; Staphylococcus aureus ; Staphylococcus

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.
Anti-Bacterial Agents ; Busan* ; 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 ; Virulence

Skin and soft tissue infections (SSTIs) caused by community-associated (CA)-methicillin-resistant Staphylococcus aureus (MRSA) have become a worldwide concern. An otherwise healthy 16-month-old Korean girl was admitted because of skin abscess on the left chest wall with a history of recurrent SSTIs since the age of 6 months. Immunologic evaluation including serum immunoglobulin level and nitroblue-tetrazolium (NBT) test were normal. Pus and nasal swab cultures revealed CA-MRSA ST714-SCCmec type IV with the Panton-Valentine leukocidin (PVL) genes, which was initially reported in the Netherlands in 2006 and has not been previously reported in Korea. The skin abscesses were successfully treated by needle aspiration and the use of antibiotics. In addition, nasal mupirocin was applied as a decolonization method. No more episodes of SSTI were observed over a follow-up period of 10 months.
Abscess ; Anti-Bacterial Agents ; Child* ; Female ; Follow-Up Studies ; Humans ; Immunoglobulins ; Infant ; Korea* ; Leukocidins ; Mupirocin ; Needles ; Netherlands ; Skin* ; Soft Tissue Infections* ; Staphylococcus aureus ; Suppuration ; Thoracic Wall

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.
Busan ; Clone Cells ; Coagulase ; Humans ; Infant, Newborn ; Intensive Care, Neonatal* ; Leukocidins ; Methicillin Resistance* ; Methicillin-Resistant Staphylococcus aureus* ; Multilocus Sequence Typing ; Prevalence*

The prevalence and molecular characteristics of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) and methicillin-susceptible S. aureus (CA-MSSA) from children with skin infection were investigated by staphylocoagulase (SC) typing, multilocus sequence typing (MLST), SCCmec typing and virulent toxins, including Panton-Valentine leucocidin (PVL), and exfoliative toxins (ET). Among 69 cases of CA-S. aureus for a 3 month period from March to June, 2014 at hospital in Busan, 28 (40.6%) were MRSA and 41 (59.4%) were MSSA. Of the 28 CA-MRSA isolates, two major clones were identified as SC type Vb-ST72-SCCmec type IV (53.6%) and SC type l-ST89-SCCmec type II variant (42.8%), and the remaining one (3.6%) was SC type lll-ST8-SCCmec type IV. In CA-MSSA, the prevalent clone was SC type Vb-ST72 (29.3%), followed by SC type Vb-ST188 (21.9%), SC type Va-ST121 (19.5%) and SC type lV-ST30 (9.6%). None was positive for PVL gene, and all of the SC type l-ST89-SCCmec type II variant clones were ETB gene positive. The data suggest that there are significant clonal relatedness with specific SC types, and genetic diversities in both community strains isolated from children with skin infections.
Busan ; Child* ; Clone Cells ; Coagulase ; Exfoliatins ; Genetic Variation ; Humans ; Korea ; Leukocidins ; Methicillin Resistance* ; Methicillin-Resistant Staphylococcus aureus ; Multilocus Sequence Typing ; Prevalence ; Skin* ; Staphylococcus aureus*

Although pandemic community-associated (CA-) methicillin-resistant Staphylococcus aureus (MRSA) ST30 clone has successfully spread into many Asian countries, there has been no case in Korea. We report the first imported case of infection caused by this clone in a Korean traveler returning from the Philippines. A previously healthy 30-yr-old Korean woman developed a buttock carbuncle while traveling in the Philippines. After coming back to Korea, oral cephalosporin was given by a primary physician without any improvement. Abscess was drained and MRSA strain isolated from her carbuncle was molecularly characterized and it was confirmed as ST30-MRSA-IV. She was successfully treated with vancomycin and surgery. Frequent international travel and migration have increased the risk of international spread of CA-MRSA clones. The efforts to understand the changing epidemiology of CA-MRSA should be continued, and we should raise suspicion of CA-MRSA infection in travelers with skin infections returning from CA-MRSA-endemic countries.
Adult ; Bacterial Toxins/metabolism ; Carbuncle/microbiology ; Cephalosporins/therapeutic use ; Community-Acquired Infections/drug therapy/microbiology ; Exotoxins/metabolism ; Female ; Humans ; Leukocidins/metabolism ; Methicillin Resistance ; Methicillin-Resistant Staphylococcus aureus/*isolation & purification ; Philippines ; Republic of Korea ; Staphylococcal Skin Infections/*drug therapy/surgery ; Travel ; Vancomycin/therapeutic use