• 한국축산식품학회지
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• 제42권2호
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• pp.225-239
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• 2022

As commensal colonizers in livestock, there has been little attention on staphylococci, especially non-aureus staphylococci (NAS), contaminating meat production chain. To assess prevalence of staphylococci in retail pork and slaughterhouse carcass samples in Korea, we collected 578 samples from Korean slaughterhouses (n=311) and retail markets (n=267) for isolation of staphylococci and determined antimicrobial resistance phenotypes in all the isolates. The presence of and prevalence of fusB-family genes (fusB, fusC, fusD, and fusF) and mutations in fusA genes were examined in fusidic acid resistant isolates. A total of 47 staphylococcal isolates of 4 different species (Staphylococcus aureus, n=4; S. hyicus, n=1; S. epidermidis, n=10; Mammaliicoccus sciuri, n=32) were isolated. Fusidic acid resistance were confirmed in 9/10 S. epidermidis and all of the 32 M. sciuri (previously S. sciuri) isolates. Acquired fusidic acid resistance genes were detected in all the resistant strains; fusB and fusC in S. epidermidis and fusB/C in M. sciuri. Multi-locus sequence type analysis revealed that ST63 (n=10, 31%) and ST30 (n=8, 25%) genotypes were most prevalent among fusidic acid resistant M. sciuri isolates. In conclusion, the high prevalence of fusB-family genes in S. epidermidis and M. sciuri strains isolated from pork indicated that NAS might act as a reservoir for fusidic acid resistance gene transmissions in pork production chains.

• 한국축산식품학회지
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• 제43권5호
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• pp.792-804
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• 2023

Non-aureus staphylococci (NAS), particularly antimicrobial-resistant NAS, have a substantial impact on human and animal health. In the current study, we investigated (1) the species profiles of NAS isolates collected from healthy broilers, farm environments, and farm workers in Korea, (2) the occurrence of antimicrobial-resistant NAS isolates, especially methicillin resistance, and (3) the genetic factors involved in the methicillin and fluoroquinolone resistance. In total, 216 NAS isolates of 16 different species were collected from healthy broilers (n=178), broiler farm environments (n=18), and farm workers (n=20) of 20 different broiler farms. The two most dominant broiler-associated NAS species were Staphylococcus agnetis (23.6%) and Staphylococcus xylosus (22.9%). Six NAS isolates were mecA-positive carrying staphylococcal cassette chromosome mec (SCCmec) II (n=1), SCCmec IV (n=1), SCCmec V (n=2), or nontypeable SCCmec element (n=2). While two mecA-positive Staphylococcus epidermidis isolates from farm workers had SCCmec II and IV, a mecA-positive S. epidermidis isolate from broiler and a Staphylococcus haemolyticus isolate farm environment carried SCCmec V. The occurrence of multidrug resistance was observed in 48.1% (104/216 isolates) of NAS isolates with high resistance rates to β-lactams (>40%) and fusidic acid (59.7%). Fluoroquinolone resistance was confirmed in 59 NAS isolates (27.3%), and diverse mutations in the quinolone resistance determining regions of gyrA, gyrB, parC, and parE were identified. These findings suggest that NAS in broiler farms may have a potential role in the acquisition, amplification, and transmission of antimicrobial resistance.

• 대한미생물학회지
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• 제22권4호
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• pp.445-451
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• 1987

Coagglutination method is widely used for the diagnosis of Salmonella infection. This test, however, has a disadvantage of false positive reaction due to the coagglutination of staphylococci with non-specific immune complexes or anti-staphylococci antibody in serum. Salmonell O antigen was detected by enzyme immunoassay with protein A-bearing Staphylococcus aureus as in the solid phase. Horse radish peroxidase was labeled to IgG specific against Salmonella O antigen. This enzyme immunoassay was much more sensitive than conventional coagglutination method without false poitive agglutination. To improve the sensitivity for detection of Salmonella O antigen in samples, we tried to determine the optimal concentration of normal IgG that inhibits non-specific binding of horse radish peroxidase labeled IgG to staphylococci, and to establish the optimal condition of reaction between antigen-antibody complex and staphylococci. Non-specific binding of horse radish peroxidase labeled specific IgG to staphylococci was almost blocked when the enzyme labeled IgG was 500-fold diluted with phosphate buffered saline containing 2mg/ml of normal IgG. When staphylococci coated with antibody to Salmonella O antigen were mixed with antigen-antibody complex and then incubated for 1 hour at room temperature, the minimal detectable concentration of Salmonella O antigen was 1ng/ml. The sensitivity of enzyme immunoassay was 100-fold greater than a conventional coagglutination method. This enzyme immunoassay could be expected as an improved method for detection of other infectious agents.

• 대한임상검사과학회지
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• 제49권4호
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• pp.420-426
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• 2017

메치실린 내성 포도알균(methicillin resistant Staphylococci, MRS)는 인체 여러 부위에서 집락화 될 수 있으며 의료기관과 연관된 사람에서 흔히 분리된다. 이 연구는 밀접한 단체생활을 하는 일개 고등학교 한 개 반의 학생들 손과 그들이 사용하는 책상에서 MRS 균의 오염 정도를 평가하고자 하였다. Staphylococcus aureus가 28명의 학생의 손 중에서 2 균주가 분리되었으며 모두 메치실린에 감수성이었다. 응고인자 음성 포도알균(coagulase negative Staphylococci, CoNS)는 26 균주가(26/28, 92.9%) 분리되었으며 이들 균주 중 14 균주는 메치실린 내성균(MRCoNS)이었다. 14 MRCoNS 중 S. warneri가 가장 흔하였으며(8/14, 57%), 이들은 대부분의 $non-{\beta}-lactam$ 항생제에 감수성 이었다. 31개의 책상에서는 S. aureus는 분리되지 않았으나 26 CoNS (26/31, 83.9%)가 분리되었다. 손과 책상에서 분리된 포도알균 이외의 균은 Micrococcus와 Bacillus spp.이었다. 결론적으로 MRSA는 이번 연구에서 분리되지 않았으나 mecA 유전자를 갖고 있는 MRCoNS는 학생들의 손에서 높은 비율로 분리되었다. 손씻기와 같은 예방 교육을 강화할 뿐만 아니라 이들 균의 오염 및 보균율 등의 조사와 같은 능동적 감시 등이 이들 균의 감염예방과 전파 차단을 위해 필요할 것으로 사료된다.

• Journal of Microbiology
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• 제45권4호
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• pp.286-290
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• 2007

The purpose of this study was to investigate the prevalence and genetic mechanisms of erythromycin resistance in staphylococci. A total of 102 erythromycin resistant non-duplicate clinical isolates of staphylococci [78. coagulase negative stapylococci (CNS), 24 Staphylococcus aureus] were collected between October 2003 and August 2004 in Istanbul Faculty of Medicine in Turkey. The majority of the isolates were from blood and urine specimens. Antimicrobial susceptibilities were determined by the agar dilution procedure and the resistance phenotypes by the double disk induction test. A multiplex PCR was performed, using primers specific for erm(A), erm(B), erm(C), and msrA genes.. Among the 78 CNS isolates, 57.8% expressed the $MLS_{B}-constitutive$, 20.6% the $MLS_{B}-inducible$, and 21.6% the $MS_B$ phenotypes. By PCR, 78.2% of these isolates harbored the erm(C) gene, 8.9% erm(A), 6.4% erm(B), and 11.5% msrA genes. In S. aureus, the constitutive $MLS_B$ (58.3 %) was more common than the inducible phenotype (20.8%). erm(A) was detected in 50% and erm(C) in 62.5% of the isolates, while 37.5% contained both erm(A) and erm(C). erm(C)-associated macrolide resistance was the most prevalent in CNS, while ermC) and erm(A, C) was the most prevalent in S. aureus.

• 약학회지
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• 제51권2호
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• pp.108-114
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• 2007

The predominant Macrolides-Lincosamide-Streptogramin B (MLS$_B$) antibiotics resistance genes in staphylococci are erm(A) and erm(C). There is the phenomenon that the ratio of constitutively MLS$_B$ antibiotics resistance (cMLS) in erm(A) is much higher than in erm(C). Thus, we confirmed that the difference of the mutation ratio between erm(A) and erm(C) makes the phenomenon. We examined 8 staphylococci carrying inducibly expressed (iMLS) erm(A) or erm(C) genes. After overnight incubation in the presence of the non-inducer MLS$_B$ antibiotics, spontaneous mutants constitutively expressed MLS$_B$ resistance were selected. Against our expectation, the mutation ratio of erm(A) was lower than erm(C). Therefore, possibilities of other factors determining the ratio of cMLS phenotype might be concerned. All the mutants showed sequence alterations in translational attenuator and all the alterations seemed to give rise to change the second structure of mRNA to express constitutively. For erm(A), 4 different types of sequence deletions ranging from 72 bp to 122 bp and 3 different types of duplications ranging 24 bp to 93 bp were detected. Also, there were 9 different types of duplications ranging 15bp to 154bp in erm(C).

• Genomics & Informatics
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• 제21권3호
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• pp.34.1-34.10
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• 2023

Nosocomial infections, commonly referred to as healthcare-associated infections, are illnesses that patients get while hospitalized and are typically either not yet manifest or may develop. One of the most prevalent nosocomial diseases in hospitalized patients is pneumonia, among the leading causes of mortality and morbidity. Viral, bacterial, and fungal pathogens cause pneumonia. More severe introductions commonly included Staphylococcus aureus, which is at the top of bacterial infections, per World Health Organization reports. The staphylococci, S. aureus, strain RMI-014804, mesophile, on-sporulating, and non-motile bacterium, was isolated from the sputum of a pulmonary patient in Pakistan. Many characteristics of S. aureus strain RMI-014804 have been revealed in this paper, with complete genome sequence and annotation. Our findings indicate that the genome is a single circular 2.82 Mbp long genome with 1,962 protein-coding genes, 15 rRNA, 49 tRNA, 62 pseudogenes, and a GC content of 28.76%. As a result of this genome sequencing analysis, researchers will fully understand the genetic and molecular basis of the virulence of the S. aureus bacteria, which could help prevent the spread of nosocomial infections like pneumonia. Genome analysis of this strain was necessary to identify the specific genes and molecular mechanisms that contribute to its pathogenicity, antibiotic resistance, and genetic diversity, allowing for a more in-depth investigation of its pathogenesis to develop new treatments and preventive measures against infections caused by this bacterium.

• 대한임상검사과학회지
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• 제42권2호
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• pp.86-91
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• 2010

We evaluated the performance of a novel screening test, PBP2a MRSA rapid kit (Dinona Inc., Iksan, Korea), for methicillin-resistant Staphylococcus aureus (MRSA) based on a immunochromatographic assay. The test is able to detect penicillin-binding protein 2a (PBP2a) using the nasal specimens from health care workers. The nasal specimens were obtained from 69 healthcare workers and were incubated in enrichment broth followed eight hours incubatin in BHI with cefoxitin $4{\mu}g/mL$. These broth were tested by PBP2a Rapid Kit. The enrichment broths were also directly tested for tube coagulase using the conventional identification method. 19 of 22 MRSA showed positive results by PBP2a rapid test and direct coagulase test (the sensitivity for detection of MRSA, 86.36%). While, 8 of 47 non-MRSA showed false positive results for the two tests. All of the 8 non-MRSA which showed false positive were co-colonizing isolates with MRCNS and MSSA. In addition, 46 of 49 methicillin-resistant staphylococci (MRS) showed positive results for PBP2a MRSA rapid kit (the sensitivity for detection of MRS, 93.8%), and all of 20 non-MRS showed negative results (specificity, 100%). The combination of PBP2a MRSA rapid kit and direct coagulase test showed the good sensitivity for detection of MRSA from anterior nares but frequently showed false positive results from the co-colonizing carrier with MRCNS and MSSA.

• 대한임상검사과학회지
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• 제49권4호
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• pp.407-412
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• 2017

본 연구에서는 계대배양과 세균 동정 시험에 소요되는 시간을 단축하고, 혈류감염의 새로운 검사 방법을 모색하여 간단하고 신속 정확한 동정 결과를 도출할 목적으로 질량분석기를 이용하여 다음과 같은 결과를 얻었다. 혈액배양에서 한 가지 세균만 배양된 검체는 총 254개였으며, Vitek 2에서 208주(81.8%)의 세균을 동정되었으며, 45주는 동정되지 않았다. 동정된 세균 중 그람양성 세균이 146개(57.5%), 그람음성 세균이 108개(42.5%)이었다. 전체적으로 233개는 종(species) 수준까지 동정 되었으며, 21개는 속(genus)수준까지 동정 되었다. 동정 오류는 Propionibacterium acnes를 Clostridium bifermentans로 동정 되었다. 균종별로는 enterobacteriaceae, glucose non-fermentative bacilli (GNFB), staphylococci의 정확도는 각각 81/83 (97.6%), 12/15 (80.0%), 72/85 (84.7%)로 나타났다. Vitek 2에 의한 표준법과 Vitek MS에 의한 직접법에 의한 동정의 일치율은 81.8%이었으며, 45주는 동정되지 않았다. 동정되지 않은 세균들의 대부분은 그람양성 세균(n=37)이었고, 그람양성 세균은 streptococci (14), coagulase-negative staphylococci (CNS) (11), enterococci (3), Staphylococcus aureus (2), Micrococcus spp. (2), Bacillus spp. (2) 그리고 Actinomyces odontolyticus, Finegoldia mag na, Peptostreptococcus spp.가 각각 1건씩 이었다. 결과 보고 시간은 기존의 검사 방법보다 24~72시간까지 단축되었다. 산소성 배양과 무산소성 배양 사이의 동정률의 차이는 없었으나 무산소성 배양을 사용하면 용해 과정이 필요 없어 검체 준비 시간을 단축할 수 있었다. 이상의 연구 결과로 혈액배양병에서 직접 동정하는 방법은 정확하고 결과 보고 시간이 신속하여 환자의 치료에 매우 유용할 것이라 생각된다. 향후 추가적인 연구에서는 본 연구에서 정확성이 부족했던 사슬알균(streptococci)과 혈장응고효소 음성 포도알균(CNS)을 동정하기 위한 방법을 더욱 개선할 필요가 있을 것으로 사료된다.

• Tuberculosis and Respiratory Diseases
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• 제59권4호
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• pp.389-396
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• 2005

목 적 : 중환자실 환자에서 중심정맥관 관련 감염증은 원내 감염의 주요 부분을 차지한다. 이러한 중심 정맥관 관련 감염증을 감소시키기 위하여 chlorhexidine-silver sulfadiazine coated catheter (CHSS) 사용에 대한 임상적 유용성에 대해서는 논란의 여지가 있지만, 국내에서는 아직 이와 관련된 보고가 없었다. 본 연구는 non-coated catheter (NCC)와 CHSS의 중심 정맥관 관련 감염증의 차이를 비교하고자 하였다. 대상 및 방법 : 2004년 1월부터 12월까지 12개월간 서울아산병원 내과계 중환자실에 입원하여 48시간 이상 중심정맥관을 삽입하였던 446 예을 대상으로 하였다. NCC(n=187)과 CHSS (n=259)에서 중심정맥관과 환자의 특성, 중심정맥관 삽입 위치, 평균 삽입 일수, 집락화중심정맥관 관련 감염증의 빈도, 및 원인균 등에 대하여 후향적인 방법으로 조사하였다. 결 과 : 1) NCC와 CHSS에서 환자군의 나이 ($62{\pm}16$, $63{\pm}15$; p=0.42) 세, 성비 (94:50, 141:69; p=0.9), 중환자실 재원일수 ($29{\pm}37$, $26{\pm}44$ ;p=0.42) 일, 인공 호흡기 사용 기간 ($17{\pm}22$, $15{\pm}19$; p=0.17) 일, 카테터 삽입 시 APACHE III 점수는 ($81{\pm}34$, $82{\pm}37$; p=0.61) 차이가 없었다. 2) 평균 카테터 삽입 기간은 NCC $11{\pm}8$ 일, CHSS $11{\pm}9$ 일 이었고(p=0.98), 총 카테터 일수는 NCC 2176일, CHSS 3035 일 이었다. NCC와 CHSS에서 카테터 감염 발생 환자는 각각 9명 (4.8%), 4명(1.5%) 으며, 1000 catheter-day당 감염 건수는 4.1건, 1.3건 이었다(p=0.04). 삽입 위치에서는 내경 정맥 삽입 시 CHSS에서 NCC 보다 중심정맥관 관련 감염증이 감소하였다 (p=0.01). 3) 중심정맥관 관련 감염증에서 동정된 균은 NCC에서 Stazfphylococcus aureus 3명, Candida species 3명, coagulase-negative Staphylococci 2명, Klebsiella 1명, 이었고 CHSS는 coagulase-negative Staphylococci 2명, Candida species 2명, Proteus 1명 이었다. 결 론 : 내과계 중환자실 환자에서 중심정맥관 삽입 시 NCC에 비해 CHSS에서 중심정맥관 감염율이 감소하였으며, 특히 삽입 위치가 내경 정맥일 때 유의한 감소를 보였다.