• 한국축산식품학회지
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• 제40권5호
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• pp.758-771
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• 2020

This study was to investigate the prevalence and characteristics of antimicrobial-resistant Staphylococcus aureus and methicillin-resistant S. aureus (MRSA) from 4,264 retail meat samples including beef, pork, and chicken in Korea between 2013 and 2018. A broth microdilution antimicrobial susceptibility testing was performed for S. aureus. Molecular typing by multilocus sequence typing (MLST), spa typing, and pulsed-field gel electrophoresis (PFGE), was performed on mecA-positive S. aureus strain. S. aureus was isolated at a rate of 18.2% (777/4,264), of which MRSA comprised 0.7% (29 strains). MLST analysis showed that 11 out of the 29 MRSA isolates were predominantly sequence type (ST) 398 (37.9%). In addition, ST72, ST692, ST188, ST9, and ST630 were identified in the MRSA isolates. The spa typing results were classified into 11 types and showed a high correlation with MLST. The antimicrobial resistance assays revealed that MRSA showed 100% resistance to cefoxitin and penicillin. In addition, resistance to tetracycline (62.1%), clindamycin (55.2%), and erythromycin (55.2%) was relatively high; 27 of the 29 MRSA isolates exhibited multidrug resistance. PFGE analysis of the 18 strains excluding the 11 ST398 strains exhibited a maximum of 100% homology and a minimum of 64.0% homology. Among these, three pairs of isolates showed 100% homology in PFGE; these results were consistent with the MLST and spa typing results. Identification of MRSA at the final consumption stage has potential risks, suggesting that continuous monitoring of retail meat products is required.

• KSBB Journal
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• 제14권4호
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• pp.460-464
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• 1999

Methicillin-resistant Staphlococcus aureus(MRSA)는 다양한 항생제에 저항성을 나타내며 제 3세대 cephalosporin계가 보급된 1980년대 이후 원내 감염의 중요 원인균으로 대두되고있다. 그러나 MRSA 동정의 오류나 실수로 인한 부적절한 치료에 문제가 있으며 항생제의 오용으로 인한 다제약제 내성획득이 임상에서 심각한 문제가 되거 있다. 따라서 MRSA 감염의 적절한 치료는 이 원인 균의 신속하고 믿을 수 있는 동정을 필요로 한다.본 연구에서는 분자 생물학적인 동정법을 확립하기 위하여 항생제의 내성 기구인 페니실린 결합 단백질 2‘(PBP2')를 암호화하는 mec A 유전자를 PCR 방법으로 증폭하여 MIC test 결과와 비교하여 MRSA를 동정하는데 PCR법이 유용한지를 판명하였다.각 환자의 다종 검체로부터 S. aureus 120균주를 분리하여 oxcillin으로 MIC test를 한 결과 MRSA의 비율로는 농에서는 MRSA가 61.9%로 가장 높게 판명되었다. 120균주 중 MRSA 40균주, MSSA 40균주를 성별하여 PCR 방법으로 동정하여 MIC test와 비교 한 결과, MRSA 1균주(2.5%), MSSA는 2균주(5%)의 차이만이 MIC test와 상이성을 나타내었다. 이러한 결과로 볼 때 PCR법으로 MRSA를 동정하는 것은 유용하며 일상검사 업무로서 활용성이 높을 것으로 판단되었다.

• 대한한방내과학회지
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• 제34권3호
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• pp.278-288
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• 2013

Objectives : Methicillin-resistant Staphylococcus aureus (MRSA) has a cephalosporin and beta-lactam antibiotic-resistant strains. MRSA is one of the major pathogens causing hospital infection and the isolation ratio of MRSA has gradually increased. Consequently, increased resistance to antibiotics is causing serious problems in the world. Therefore, there is a need to develop alternative antimicrobial drugs for the treatment of infectious diseases. Methods : The antibacterial activities of Ipyo-san were evaluated against 2 strains of MRSA and 1 standard Methicillin-susceptible staphylococcus aureus (MSSA) strain by using the disc diffusion method, minimal inhibitory concentrations (MIC) assay, colorimetric assay using MTT test, checkerboard dilution test and time-kill assay performed under dark. Results : The MIC of Ipyo-san water extract against S. aureus strains ranged from 1000 to $2,000{\mu}g/ml$, so we confirmed that it had a strong antibacterial effect. Also, the combinations of Ipyo-san water extract and conventional antibiotics exhibited improved inhibition of MRSA with synergy effect. We suggest that Ipyo-san water extract against MRSA has antibacterial activity so it has potential as alternatives to antibiotic agents. For the combination test, we used Triton X-100 (TX) and DCCD for measurement of membrane permeability and inhibitor of ATPase. As a result, antimicrobial activity of Ipyo-san water extract was affected by the cell membrane. Conclusions : We suggest that the Ipyo-san water extract lead the treatment of bacterial infection to solve the resistance and remaining side-effect problems that are the major weak points of traditional antibiotics.

• Journal of Microbiology and Biotechnology
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• 제32권12호
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• pp.1537-1546
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• 2022

Staphylococcus aureus is a cause of high mortality in humans and therefore it is necessary to prevent its transmission and reduce infections. Our goals in this research were to investigate the frequency of methicillin-resistant S. aureus (MRSA) in Taif, Saudi Arabia, and assess the relationship between the phenotypic antimicrobial sensitivity patterns and the genes responsible for resistance. In addition, we examined the antimicrobial efficiency and application of silver nanoparticles (AgNPs) against MRSA isolates. Seventy-two nasal swabs were taken from patients; MRSA was cultivated on Mannitol Salt Agar supplemented with methicillin, and 16S rRNA sequencing was conducted in addition to morphological and biochemical identification. Specific resistance genes such as ermAC, aacA-aphD, tetKM, vatABC and mecA were PCR-amplified and resistance plasmids were also investigated. The MRSA incidence was ~49 % among the 72 S. aureus isolates and all MRSA strains were resistant to oxacillin, penicillin, and cefoxitin. However, vancomycin, linezolid, teicoplanin, mupirocin, and rifampicin were effective against 100% of MRSA strains. About 61% of MRSA strains exhibited multidrug resistance and were resistant to 3-12 antimicrobial medications (MDR). Methicillin resistance gene mecA was presented in all MDR-MRSA strains. Most MDR-MRSA contained a plasmid of > 10 kb. To overcome bacterial resistance, AgNPs were applied and displayed high antimicrobial activity and synergistic effect with penicillin. Our findings may help establish programs to control bacterial spread in communities as AgNPs appeared to exert a synergistic effect with penicillin to control bacterial resistance.

• 미생물학회지
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• 제51권4호
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• pp.444-447
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• 2015

본 연구는 $SeO_2$의 메티실린-내성 S. aureus에 대한 항세균활성을 규명하고자 수행하였다. Disc diffusion method를 이용하여 $SeO_2$의 항세균 활성을 측정한 결과, 그람 양성 세균이 그람 음성 세균과 비교시 우수하였다. 사용한 그람 양성 세균 중 Streptococcus, Staphylococcs 속 세균이 Bacillus 속 간균과 비교시 더 우수하였다. 사용한 모든 MRSA에 항균활성이 나타났다. 항생제의 생육저지환을 측정한 결과, 사용한 모든 항생제에 대해 MRSA의 항균활성이 작게 나타났다. $200-500{\mu}g/disc$ 범위의 $SeO_2$ 적용시 S. aureus 및 S. aureus CCARM (MRSA)에 대한 생육저지환의 직경은 각각 20-32.7 mm 및 13.5-17.9 mm이었다. $SeO_2$의 MRSA에 대한 최소생육억제농도는 $40{\mu}g/ml$이었다. 액체배지에 0.5% 및 1%의 $SeO_2$를 첨가한 결과, MRSA의 생육이 억제 되었다. 본 $SeO_2$의 항균활성 실험 결과는 추후, $SeO_2$의 항균활성 기작의 규명, 병원성 세균 및 항생제-내성 미생물에 적용될 수 있다고 판단된다.

• 한국축산식품학회지
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• 제40권3호
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• pp.401-414
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• 2020

The emergence and persistence of methicillin-susceptible Staphylococcus aureus (MSSA) and methicillin-resistant S. aureus (MRSA) in livestock animals have been reported as a potential risk factor for transmission to humans. In this study, we investigated the nationwide prevalence and characteristics of MRSA and MSSA in the Korean beef production system, including retail markets, slaughterhouses, and cattle farms. From a total of 1,285 samples, only 5 MRSA strains were isolated: from a farmer (1 ST72 MRSA), a carcass sample from a slaughterhouse (1 ST72 MRSA), and beef cattle (3 ST5 MRSA). In addition, 11 MSSA strains were isolated from beef cattle (n=3), humans (1 farmer, 1 slaughterhouse worker, and 4 retail market workers), and carcass samples (n=1) and slaughterhouse environment (n=1). Although the prevalence of MRSA and MSSA in beef cattle was much lower than that reported in pigs, 5/5 MRSA and 2/11 MSSA strains displayed multiple drug resistance (MDR) phenotypes. Unlike the swine-associated MRSA, no correlation was found between tetracycline/zinc resistance and MDR phenotype. However, MRSA strains had an identical set of staphylococcal enterotoxins and exhibited enhanced levels of resistance to antimicrobial peptides (PMAP-36 and LL-37) compared to the MSSA strains. In conclusion, continued and systemic surveillance of livestock, meat products, and humans in close contact with livestock/meat products is necessary to prevent the transmission of MRSA and MSSA to humans.

• 한국식품영양과학회지
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• 제38권5호
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• pp.541-547
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• 2009

42가지의 천연물 시료 중 세신, 호두(열수), 골쇄보, 뽕잎, 로즈마리에서 S. aureus ATCC 25923 및 MRSA KCCM 40511에 대해 우수한 항균활성을 나타냈다. 이들 시료 중 가장 우수한 항균활성을 가지는 로즈마리를 순차 분획하여 각 분획물을 이용한 MRSA에 대한 항균활성을 알아본 결과 hexane, chloroform 분획물에서 항균활성을 나타냈으며, 각 분획물 중 hexane 분획물이 가장 높은 저해활성을 나타내었다. 또한 SEM을 통한 형태학적 관찰을 통해 분획물 처리 시 MRSA의 세포벽이 파괴되는 것을 확인할 수 있었다. 로즈마리 메탄올추출물 및 hexane 분획물은 MRSA KCCM 40511의 내성 단백질인 MecA와 MecA에 의해 합성되는 세포벽 단백질 penicillinase의 발현을 억제시킴으로써 고도 내성균의 내성을 억제시키는 것으로 나타났다.

• 대한의생명과학회지
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• 제13권3호
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• pp.189-195
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• 2007

This study was carried out to examine antimicrobial substances from medicinal plants, the ethanol extracts of 38 medicinal plants were tested for the antimicrobial activity against Staphylococcus aureus ATCC 25923 and methicillin-resistant Staphylococcus aureus ATCC 43300. The extracts of Glycyrrhiza uralensis, Sophora flavescens, Dryopteris crassirhizoma, and Pinas densiflora showed significant antimicrobial activities against both S. aureus ATCC 25923 and methicillin-resistant S. aureus ATCC 43300. The extract of Dryopteris crassirhizoma among these medical plants showed the highest antimicrobial activity. These results suggested that the extracts from Dryopteris crassirhizoma, Sophora flavescens, Pinas densiflora, and Glycyrrhiza uralensis could be the potential source of antimicrobial agents against methicillin-resistant S. aureus and S. aureus.

• Pediatric Infection and Vaccine
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• 제20권2호
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• pp.63-70
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• 2013

목 적 : 본 연구에서는 CA-MRSA로 인한 소아의 세균성 근골격계 감염의 임상양상을 연구하기로 하였다. 방 법 : 2000년 9월부터 2012년 8월까지 12년간 분당 차병원에 입원한 18세 이하의 환아 중 혈액과 관절액, 조직이나 고름의 세균 배양검사에서 S. aureus가 동정된 환아를 대상으로 의무기록을 후향적으로 분석하였다. 결 과 : 대상 환아 수는 총 31례였으며 중간값은 7세(최소 17일, 최대 18세)이다. 화농성 관절염으로 진단된 경우는 11례(35.5%), 골수염은 16례(51.6%), 화농성 관절염과 골수염이 병발된 경우는 5례(16.1%)였다. 환아의 혈액이나 관절액, 조직이나 고름 등에서 동정된 S. aureus 31례 중 MSSA는 25례(80.6%), MRSA는 6례(19.4%)였다. 검출된 균주 중 다제내성균은 관찰되지 않았다. MRSA가 배양되었던 6례는 모두 2006년 이후 발생하였다. 모든 증례에서 항생제가 투여되었으며 항생제 투여 기간은 $26.4{\pm}12.7$일이었고, 첫 항생제로 반코마이신을 동반 사용한 경우는 4례(12.9%)였으며 10례(32.3%)에서 최종 항생제로 반코마이신이 투여되었다. 결 론 : 본 연구를 통하여 최근 12년간 세균성 근골격계 감염에서 MRSA의 발생은 연구기간 후반에 편중되었다.

• 동의생리병리학회지
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• 제26권6호
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• pp.886-893
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• 2012

Methicillin-Resistant Staphylococcus aureus (MRSA) is a cephalosporin and beta-lactam antibiotic-resistant strain. In most cases, MRSA is spread from infected patients and infection rates are growing increasingly. Furthermore, increased resistance to antibiotics is causing serious problems in the world. Staphylococcus aureus is responsible for both nosocomial and community-based infections that range from relatively minor skin and soft tissue infections to life-threatening systemic infections. Therefore, there is a need to develop alternative antimicrobial drugs for the treatment of infectious diseases. In this study, we investigated antimicrobial activity of oriental medicine prescription against MRSA. The minimum inhibitory concentration (MIC) of Sohamhyung-tang water extract against S. aureus strains ranged from 500 to 2,000 ${\mu}g/mL$, so we have it confirmed that a strong antibacterial effect. Also, the combinations of Sohamhyung-tang water extract and conventional antibiotics exhibited improved inhibition of MRSA with synergy effect. We suggest that Sohamhyung-tang water extract against MRSA have antibacterial activity, it has potential as alternatives to antibiotic agent. We suggest that the Sohamhyung-tang water extract lead the treatment of bacterial infection to solve the resistance and remaining side-effect problems that are the major weak points of traditional antibiotics.