• 대한임상검사과학회지
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• 제50권2호
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• pp.110-117
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• 2018

본 연구에서는 2017년 6월부터 7월까지 국내 충남 소재 2차 의료기관의 임상검체에서 분리 된 20개 균주와 ICU환경으로부터 분리 한 4개를 포함해 총 24개의 MRSA 균주에 대한 분자유전학적 특성을 분석하기 위해 SCCmec typing과 mec complex typing을 수행하였다. 임상검체에서 분리된 MRSA 20균주의 SCCmec typing 분석 결과 SCCmec type II가 8건, type IVa가 1건, Not-typeable이 11건으로 나타났다. 의료기관 중환자실 환경에서 분리 된 MRSA 중 한 균주는 mecA 유전자를 가지고 있지 않은 것으로 확인되었으며, 나머지 세 균주는 SCCmec type II, III, IVa가 각각 한 건으로 나타났다. 임상검체와 중환자실 환경검체에서 분리된 MRSA는 SCCmec typing 결과 그 기원이 서로 다른 것으로 나타났으나, 의료기관 환경에서 분리된 1건의 경우 그 기원이 서로 일치하여 의료종사자의 손, 가운 등을 매개체로 하여 환경내의 MRSA가 환자에게 전파되었을 가능성이 있는 것으로 사료된다. 이후 추가적인 연구를 통해 좀 더 많은 수의 병원감염 관련 균주를 대상으로 추적조사를 실시 한다면 임상 현장에 감염관리와 관련한 더욱 유용한 정보를 제공할 수 있을 것으로 사료된다.

• 대한임상검사과학회지
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• 제56권2호
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• pp.115-124
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• 2024

플루오로퀴놀론(fluoroquinolone, FQ) 항균제 내성을 갖는 황색포도알균(Staphylococcus aureus)의 출현 및 확산으로 감염증 치료에 어려움을 겪고 있다. 이 퀴놀론 내성 황색포도알균(quinolone resistant S. aureus, QRSA) 에 대한 분자역학적 특성을 조사하여 치료에 도움을 주는 자료를 만들고자하였다. 대전광역시 소재 1개 종합병원에서 혈액배양 검체에서 분리된 QRSA 균주를 대상으로 mecA와 SCCmec 유전자형 분석에 따른, gyrA, gyrB 유전자의 돌연변이를 조사하였다. Ciprofloxacin 내성균주는 SCCmec typing에서 II형이 44개로 73%, IVa형이 5개로 8%, III와 V형이 1개로 2%, nontypeable 균주가 11개로 18%, levofloxacin, moxifloxacin은 II형이 44개로 73%, IVa형이 5개로 8%, III와 V형이 1개로 2%, non typeable 균주가 10개로 17%의 결과를 보였다. gyrA와 gyrB 영역 모두에서 58개로 96.7%, levofloxacin은 56개로 93.3%, moxifloxacin에는 57개로 95%를 나타냈다. QRSA 균주에 대한 gyrA와 gyrB의 돌연변이는 각각 6개씩 12개의 돌연변이가 확인되었다. 연구 대상 QRSA의 FQ 항균제의 내성률은 약 98%를 나타냈고, QRSA 균주에 대한 gyrA와 gyrB의 돌연변이는 각각 6개씩 12개의 돌연변이가 확인되었다.

• 한국식품위생안전성학회지
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• 제29권3호
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• pp.223-227
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• 2014

원유시료에서 분리한 methicillin 내성 황색포도알균의 분표율과 내성유전자의 분석을 분자수준에서의 실시하였다. 총 698종의 원유시료에서 286개의 포도알균속 세균을 Staphylococcus Medium 110을 이용하여 분리 후 Vitek 2 system을 이용하여 동정한 결과 94개의 황색포도알균을 확인하였다. 94개의 황색포도알균 중 총 7개의 균에서 methicillin 내성 mecA 유전자가 존재함을 확인하였다. Methicillin-resistant Staphylococcus aureus (MRSA)로 확인된 7 균주에 대해 수종의 항생제에 대한 감수성 시험, staphylococcal cassette chromosome mec (SCCmec) typing, 및 병독소유전자인 Panton-Valentine Leukocidin (pvl)유전자를 분석하였다. 그 결과 7종의 mecA 양성 MRSA 모두 ampicillin과 oxacillin에 내성이었으며 teicoplanin, vancomycin 및 ciprofloxacin에는 모두 감수성임을 확인하였다. 한편 SCCmec typing결과 7균 중 1균주는 SCCmec type II로 확인되었고 6균주는 SCCmec type IV로 확인되었으며 병독소 유전자인 pvl유전자는 검출되지 않았다.

• Journal of Microbiology and Biotechnology
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• 제29권9호
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• pp.1460-1469
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• 2019

The extensive distribution of multidrug-resistant (MDR) methicillin-resistant Staphylococcus aureus (MRSA) poses a threat to healthcare worldwide. This study aimed to investigate the MDR and molecular patterns of MRSA isolates in children admitted to the two biggest tertiary care pediatric hospitals in northern and southern Vietnam. A total of 168 MRSA strains were collected to determine antibiotic susceptibility by minimum inhibitory concentration tests. Antibiotic-resistant genes, pulsed-field gel electrophoresis, staphylococcal cassette chromosome mec (SCCmec) typing, and multilocus sequence typing were used for the molecular characterization of MRSA. Among the total strains, the MDR rate (51.8%) was significantly higher in the northern hospital than in the southern hospital (73% vs. 39%, p < 0.0001). The MDR-MRSA with the highest rates were "ciprofloxacin-erythromycin-gentamicintetracyclines" (35.6%), followed by "erythromycin-tetracycline-chloramphenicol" (24.1%), and "ciprofloxacin-erythromycin-gentamicin" (19.5%), showing an accumulative total of 79.3%. The most susceptible antibiotics were rifampicin (100%) and vancomycin (100%), followed by doxycycline (94.0%), meropenem (78.0%), and cefotaxime (75.0%). The SCCmecII strains showed greater resistance to gentamicin, ciprofloxacin, tetracycline, meropenem and cephalosporins compared with the other strains. The SCCmecII strains exhibited the highest rate in the tested genes (aacA/aphD: 55.2%, ermA/B/C: 89.7%, and tetK/M: 82.8%). ST5-SCCmecII was the predominant clone in the northern hospital, whereas SCCmecIVa was more pronounced in the southern hospital. In conclusion, our results raised concerns about the predominant MDR-MRSA strains in the pediatric hospitals in Vietnam. The north-south difference in the antibiotic resistance patterns and genetic structure of MRSA suggests different MRSA origins and various uses of antimicrobial agents between the two regions.

• 대한의생명과학회지
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• 제16권2호
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• pp.75-82
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• 2010

The molecular epidemiological characteristics of methicillin-resistant Staphylococcus aureus (MRSA) isolates have demonstrated their genetic diversity and evolution. A total of 137 strains of MRSA clinical isolates was collected from Korean healthcare facility in 2007. The MRSA clinical isolates were analyzed by molecular typings (SCCmec element and agr locus typing), virule nce factor gene detections {(Panton-Valentine leukocidin (PVL), enterotoxin, exfoliative toxin and toxic shock syndrome toxin-1), and amplified fragment length polymorphism (AFLP)}. The MRSA clinical isolates were classified as SCCmec type II-agr type 1 (2 strains), type II-agr type 2 (79 strains), type III-agr type 1 (24 strains), type III-agr type 2 (2 strains), type IV-agr type 1 (27 strains), type IV-agr type 2 (2 strains), and non-typable (1 strain, agr type 3). Based on SCCmec types, SCCmec type II (95.1%) and III (88.5%) indicated higher multidrug resistance rate than SCCmec type IV (10.3%) (P<0.001). The most common enterotoxin genes were seg (83.8%), sei (83.1%), and sec (80.2%). The tst gene was present in 86 out of 137 (62.8%) MRSA isolates. All MRSA isolates were negative for PVL and exfoliative toxin genes. The combinations of toxin genes were observed in particular SCCmec types; 97.6% of SCCmec type II strains carried sec, seg, sei and tst genes, 73.0% of SCCmec type III strains carried sea gene, and 89.7% of SCCmec type IV strains carried sec, seg and sei genes. Each of the SCCmec types of MRSA isolates had distinct AFLP profile. In conclusion, SCCmec type II, agr type 1 and 2 have demonstrated to be the most common types in Korea, and the results indicated that the virulence factors are closely associated with their molecular types (SCCmec and agr types).

• 대한임상검사과학회지
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• 제52권2호
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• pp.128-135
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• 2020

본 연구에서는 환자의 비강으로부터 분리 배양된 총 39건의 MRSA 분리 배양 균주를 이용해 mecA 유전자 검출, SCCmec typing과 mec complex typing을 분석해 보고자 하였다. 임상 환자의 비강으로부터 분리 배양된 MRSA 총 39주 중 SCCmec type-II가 24건, type-II/IVa가 2건, type-II/V가 1건, type-IVa가 1건, not-typeable이 11건으로 분석되었으며, mec complex type A가 29건, not-typeable이 10건이었으며, type B는 없는 것으로 분석 되었다. 결론적으로, 환자의 비강으로부터 분리된 MRSA 분리 배양 균주 중 SCCmec type-II와 mec complex type A 아형이 가장 많이 분포하고 있었으며, 이 결과는 의료기관 획득 MRSA에 관한 다른 연구결과와 유사한 결과를 나타냈다. 이후 환자의 비강으로부터 분리 배양된 not-typeable 아형의 MRSA 균주를 대상으로 국내에서 발견되는 새로운 MRSA 아형 규명에 관한 추가 연구가 필요할 뿐만 아니라, MRSA 분리 배양 균주의 아형을 분석함으로써 그 분자적 특성을 분석한 결과를 바탕으로 병원 감염관리를 위한 기초자료를 제공할 수 것으로 사료된다.

• 대한의생명과학회지
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• 제26권3호
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• pp.244-248
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• 2020

Skin and soft tissue infections caused by methicillin-resistant Staphylococcus aureus (MRSA) can occur especially in community populations such as military training camps. We investigated antimicrobial resistance patterns and molecular epidemiological characteristics of MRSA isolated from nasal swabs in healthy army trainees. From January 2018 to March 2018, one MRSA strain was isolated from nasal swab and hand of healthy army trainees. mecA gene detection, SCCmec and mec complex typing were performed to analyze the antimicrobial resistance patterns and molecular epidemiological characteristics of MRSA isolates. As a result, SCCmec and mec complex type of MRSA isolate from military trainees was not-typeable (n=1). In conclusion, not-typeable subtype of MRSA isolate from military trainees need to be confirmed by continuous follow-up study to determine whether there is a different genotype or a new subtype of genotype present in the Republic of Korea.

• 대한의생명과학회지
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• 제26권3호
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• pp.230-237
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• 2020

Staphylococcus aureus (S. aureus) is known as a bacterium that can cause skin infections, respiratory system infections, and sinusitis; however, it can exist as a normal flora rather than a pathogen. Recently, methicillin-resistant S. aureus (MRSA) infections have emerged in the community as a new variant of community-associated (CA)-MRSA. In the present study, S. aureus and MRSA were isolated and cultured by collecting samples from facilities and environments where students and educational personnel have multiple contacts on university campuses; specifically, the nostrils and hands of college students were tested from July to September of 2019. The molecular properties of the isolated MRSA were analyzed, and the one MRSA strain was isolated from the university campuses. One MRSA that was isolated and cultured on campus was the mec complex group A and staphylococcal cassette chromosome (SCC) mec type II, which is a characteristic of healthcare-associated (HA)-MRSA, and SCCmec type V, which is a characteristic of CA-MRSA. This result was similar to other studies wherein the SCCmec type II was detected in SCCmec typing analysis in CA-MRSA. To confirm whether there is a new variant of CA-MRSA in the Republic of Korea, additional follow-up studies on the analysis of virulence factors of MRSA are needed by additionally separating CA-MRSA from the body parts of university students and educational personnel.

• 대한간호학회지
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• 제37권6호
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• pp.976-985
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• 2007

Purpose: The aim of this study was to identify the present situation of hospital infection and route of infection by clarifying the transmission aspect of methicillin-resistant Staphylococcus aureus(MRSA) in a Neurosurgical Intensive Care Unit by analysing genotype. Methods: MRSA was cultured from twenty five patients with a tracheostomy, twenty five health care workers, and environments in the Neurosurgical Intensive Care Unit of one hospital in D city. Data was collected from December 21, 2004 to November 5, 2005. MRSA isolates representing each genotype were analyzed by spaA typing and a multiplex PCR method capable of identifying the structural type of the staphylococcal cassette chromosome mec(SCCmec) carried by the bacteria. Results: As the same genotype and gene sequence were found among health care workers, patients, and environments, it was assumed that there was cross transmission among them. Conclusion: This study suggests that first, as the hospital infection by MRSA between health care workers and patients in the Neurosurgical Intensive Care Unit was due to result of cross transmission and the relevance of transmission between them was verified, it is necessary to take preventive measures and conduct education. Secondly, development of nursing interventions and study of infection are needed. Thirdly, consistent investment in prevention against hospital infections and environmental renovation is needed.

• Journal of Veterinary Science
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• 제23권6호
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• pp.12.01-12.10
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• 2022

Background: Staphylococcus aureus and Streptococcus agalactiae are the main cause of clinical mastitis in dairy cattle in Argentina, whereas coagulase-negative staphylococci (CNS) and environmental streptococci are the main cause of subclinical mastitis. Bacteria isolated from infected animals show increasing antimicrobial resistance. Objectives: This study aims to determine the antimicrobial resistance of staphylococci and streptococci isolated from milk with mastitis, and to genotypically characterize the methicillin-resistant (MR) staphylococci. Methods: Isolation was performed on blood agar and identification was based on biochemical reactions. Antimicrobial susceptibility was according to the Clinical and Laboratory Standards Institute guidelines. The antimicrobial resistance genes, SCCmec type and spa type were detected by the polymerase chain reaction method. Results: We isolated a total of 185 staphylococci and 28 streptococci from 148 milk samples. Among the staphylococcal isolates, 154 were identified as CNS and 31 as S. aureus. Among the 154 CNS, 24.6% (n = 38) were resistant to penicillin, 14.9% (n = 23) to erythromycin, 17.5% (n = 27) to clindamycin, 6.5% (n = 10) to cefoxitin and oxacillin. Among the S. aureus isolates, 16.1% (n = 5) were resistant to penicillin, 3.2% (n = 1) to cefoxitin and oxacillin (MRSA). Six MR isolates (5 CNS and 1 MRSA) were positive to the mecA gene, and presented the SCCmec IVa. The MRSA strain presented the sequence type 83 and the spa type 002. Among the 28 streptococcal isolates, 14.3% (n = 4) were resistant to penicillin, 10.7% (n = 3) to erythromycin and 14.3% (n = 4) to clindamycin. Conclusions: The present findings of this study indicate a development of antimicrobial resistance in main bacteria isolated from cows with mastitis in Argentina.