• 생명과학회지
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• 제16권4호
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• pp.664-671
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• 2006

1996년부터 2005년까지 부산지역에서 분리된 Salmonella enterica serovar Typhi 균주에 대한 항균제 내성 변화양상 및 Pulsed-field gel electrophoresis(PFGE)를 이용한 분리주의 분자역학적 형별을 분석하였다. 전체 424주에 대한 항균제 감수성 시험결과 multidrug-resistant (MDR) 6주(1.4%)와 nalidixic acid에만 내성을 보이는 2주를 제외한 나머지 416주(98.1%)가 시험 항균제 18종 모두에 감수성을 보였다. 부산지역 분리 장티푸스균의 유전적 이질성을 확인하고자 실시한 산발 분리 50주의 PFGE/XbaI 시험결과, 최소 32종의 다양한 패턴이 나타났다. 각 패턴별로 제한효소 절편 수는 13개에서 18개까지였고, 절편크기는 약 20 kb에서 630 kb 범위였다. 본 시험결과 부산지역의 장티푸스의 산발 또는 집단 발생시 PFGE는 유용한 역학적 지표로 사용가능함을 알 수 있었으며 또한 전국적 PulseNet 구축의 기초 자료로서 활용도가 높을 것으로 사료된다.

• 한국동물위생학회지
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• 제32권3호
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• pp.257-264
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• 2009

Subtyping of Brucella abortus isolates is epidemiologically important for monitoring of bovine brucellosis outbreaks. Pulsed-field gel electrophoresis (PFGE) is considered as a gold standard of molecular typing methods to study the DNA polymorphisms of bacteria. In this study, we analyzed using PFGE the DNA fragment profiles of B. abortus isolated in Gyeongbuk province from 1998 to 2006. The genomic DNA was digested with the restriction endonuclease Xba I, Xho I and Smi I followed gel electrophoresis. No distinguishable patterns of the genomic DNA digested with Xba I and Xho I were observed among the field isolates of B. abortus tested in this study. But Smi I restriction enzyme resulted in two PFGE patterns consisting of 13-15 bands that ranged in size from 33 to 668bp by standard marker. The cluster analysis by DNA fingerprinting software showed 93.75% similarity between two PFGE patterns. No different PFGE patterns were recognized among the isolates originated from various years, regions and cow breeds.

• Journal of Preventive Medicine and Public Health
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• 제38권2호
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• pp.182-188
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• 2005

Objectives: This study was undertaken to investigate the source of infection and mode of transmission of shigellosis, which occurred sporadically among residents and students in a subcounty of Cheongwon county, Chungbuk province, Korea, from June 4 to July 3 2003. Methods: 692 subjects completed a questionnaire and provided a swab for microbiological examinations,and 7 environmental specimens were examined for bacterial organisms. PFGE (pulsed-field gel electrophoresis) and fingerprinting were performed to find the genetic relationship among the temporally associated sporadic isolates. Results: A total of 29 patients had symptoms consistent with the case definition, with 13 confirmed and 16 suspected cases. The frequency of diarrhea was 6 times or more a day (80.8%), with a duration of 1 to 4 days (88.5%) in most cases. The most common symptoms accompanying the diarrhea were fever (80.9%) followed by abdominal pain (76.9%), headache (65.4%), chill (61.5%), vomiting (46.2%) and tenesmus (15.4%). The epidemic curve was characteristic of a person-to-person transmission. The PFGE and fingerprinting demonstrated identical or similar DNA patterns among the 3 Shigella sonnei isolates (A51, A53 and A61 types) found in this outbreak. Conclusion: A genetically identical strain of S. sonnei was estimated to be the cause of this outbreak, and the mode of transmission was most likely person-to-person.

• 대한수의학회지
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• 제50권3호
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• pp.239-246
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• 2010

Among 203 avian pathogenic Escherichia coli (APEC) isolated from poultry with colibacillosis in korea, 14 isolates were selected from total 68 isolates transferred R plasmid and classified into 5 groups on the basis of antimicrobial minimal inhibitory concentration (MIC) pattern, farm source and O serotype. An association between clonal origin and R plasmid of them was investigated by R plasmid profile, restriction endonuclease analysis and pulsed-field gel electrophoresis (PFGE). The strains that showed the same or very similar antimicrobial MIC pattern, but different farm source and O serotype, revealed different PFGE pattern, which seemed to be different clonal origin. And the strains that showed the same MIC pattern and O serotype, revealed different PFGE pattern, seemed to be originated from different clone. Also the strains showing the same MIC pattern and farm source, but different O serotype, revealed to be different clonal origin. The strains that showed the same or similar MIC pattern, farm source, and O serotype, revealed identical or similar PFGE pattern, which seemed to belong to be one clone. Meanwhile, horizontal transfer of R plasmid seems to be common in APEC with regardless of O serotype and clone of the strains. These results indicate that rapid and accurate epidemiological survey of APEC can be possible by the combination of O serotyping, plasmid profiling and PFGE analysis following the classification of them into groups of antimicrobial drug resistance pattern.

• 한국동물위생학회지
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• 제30권3호
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• pp.353-362
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• 2007

A total of 1,354 samples was collected from bovine and porcine carcass from January 2005 to December 2006 in a slaughter house. Twenty five strains(1.8%) of Listeria monocytogenes were isolated from 1,354 samples using selective media. Ten(1.4%) L monocytogenes were isolated from the 677 of bovine carcasses, and 15(2.2%) were isolated from the 677 of porcine carcasses. Among 15 L mono-cytogenes from porcine, 11 siolates were serovars 1/2c, followed by 1/2b (3 strains, 20.0%) and 1/2a(1 strain) Out of 10 bovine samples, positive cases in 1/2a were 9 strains (90.0%), 1/2b were 1 strains(10.0%). PCR primers were selected to amplify a 520-base pair(bp) DNA fragment from the listeolysin O gene (hlyA) of L mono-cytogenes. A 520-bp product was detected in PCR with DNA from L monocytogenes, but not from the other Listeria species tested. A total of 25 L monocytogenes strains were analysed by PFGE after digestion with Apa I. PFGE analysis of genomic DNA showed the $14{\sim}18$ fragments ranging in size from 30 to 550 kb, resulting in 14 patterns.

• 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.

• Journal of Microbiology
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• 제43권6호
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• pp.546-554
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• 2005

We assessed the genetic relations and epidemiological links among bloodstream isolates of Candida albicans, which were obtained from a university hospital over a period of five years. The 54 bloodstream isolates from the 38 patients yielded 14 different karyotypes, 29 different patterns after digestion with SfiI (REAG-S), and 31 different patterns after digestion with BssHII (REAG-B) when analyzed using three different pulsed-field gel electrophoresis (PFGE) typing methods. In 11 patients with serial blood stream isolates, all strains from each patient had the same PFGE pattern. The dendrograms for all of the strains revealed that the distribution of similarity values ranged from 0.70 to 1.0 in the REAG-S patterns, and from 0.35 to 1.0 in the REAG-B patterns. Overall, the combination of the three different PFGE methods identified 31 distinct types, reflecting the results obtained using the REAG-B alone different. different Five PFGE types were shared among 22 isolates from 12 patients. These types of strains were more frequently associated with central venous catheter-related fungemia than the other 26 type strains $(92\%\;versus\;31\%;\;P<0.005)$. Of five PFGE types, four isolates were determined to be epidemiologically related: each of these types was primarily from two or three patients who had been hospitalized concurrently within the same intensive care unit. Our results suggest that the REAG-B constitutes perhaps the most useful PFGE method for investigating C. albicans candidemia and also shows that a relatively high proportion of C. albicans candidemia may be associated with exogenous acquisition of clonal strains.

• Journal of Microbiology and Biotechnology
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• 제32권12호
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• pp.1605-1614
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• 2022

The strains associated with foodborne Salmonella enterica Thompson outbreaks in Korea have not been identified. Therefore, we characterized S. Thompson strains isolated from chocolate cakes linked to foodborne outbreaks in Korea. A total of 56 strains were isolated from preserved cake products, products in the supply chain distribution, the manufacturer's apparatus, and egg white liquid products used for cream preparation. Subsequently, serological typing, pathogenic gene-targeted polymerase chain reaction (PCR), pulsed-field gel electrophoresis (PFGE), and whole-genome multi-locus sequence typing (wgMLST) were performed to characterize these isolates. The antigen formula of all isolates was 7:k:1,5, namely Salmonella enterica subsp. enterica Serovar Thompson. All 56 isolates harbored invA, his, hin, and stn, and were negative for sefA and spvC based on gene-targeted PCR analyses. Based on PFGE results, these isolates were classified into one group based on the same SP6X01.011 pattern with 100% similarity. We selected 19 strains based on the region and sample type, which were subjected to wgMLST. Although the examined strains showed 100% similarity, they were classified into seven clusters based on allelic differences. According to our findings, the cause of these outbreaks was chocolate cake manufactured with egg white liquid contaminated with the same Salmonella Thompson. Additionally, comparative analysis of wgMLST on domestic isolates of S. Thompson from the three outbreaks showed genetic similarities of over 99.6%. Based on the results, the PFGE and wgMLST combination can provide highly resolved phylogeny and reliable evidence during Salmonella outbreak investigations.

• Clinical and Experimental Pediatrics
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• 제49권2호
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• pp.150-156
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• 2006

목 적 : 2000년 6월과 7월에 본원 신생아 중환자실에서는 ESBL 생성 K. pneumoniae에 의한 패혈증이 집단 발생하여 전체 환아에 대한 보균 상태를 파악하고 감염관리를 위해 감시배양을 실시하였다. 당시 집단 보균 상태임을 발견하여 보균자에 대한 격리를 실시한 결과 집단보균을 해결할 수 있었으나 대부분의 환아가 보균 상태로 퇴원하였다. ESBL 생성 K. pneumoniae는 대변 내 균이 장착되어서 입원 환아들간에 집단 감염을 일으킬 수 있으며, 이러한 균주에 의한 집단감염은 치료와 예후에 중요한 인자로 작용될 것으로 생각된다. 이에 저자들은 집단보균 발생시 분리된 ESBL 생성 K. pneumoniae의 분자 역학적 특징과 보균환아들의 추적관찰 결과를 알아보고자 본 연구를 시행하였다. 방 법 : 2000년 7월 28일부터 12월 30일까지 입원환아를 대상으로 직장내 도말법으로 감시배양검사를 시행하였다. 감시배양검사는 재원환아들에서 1주 간격으로 시행하였고, 신환은 입원 당일에 시행하였다. 균주의 형별 검사를 위해서 Pulsed-field gel electrophoresis(PFGE)를 시행하였고, 보균 상태로 퇴원했던 환아들은 외래에서 대변 배양검사로 추적 관찰하였다. 결 과 : 감시 배양기간 중 총 80명(28.5%)의 환아에서 보균이 확인되었고, 퇴원시 5명(6.3%)에서 음성이 확인되었다. PFGE를 시행한 65명의 타이핑 결과, 일회의 PFGE를 시행한 53명에서 분리된 균주의 염색체 유전자 분획양상은 집단클론 6가지, 단독클론 10가지형으로 분류되었고, 집단 클론 중 A형이 28명(52.8%)으로 가장 많았고, B형이 11명(20.8%), C, D, F, G형이 각각 1명(1.9%)이었다. 2회 이상 검사를 시행한 12명 중 초기검사에서는 A형이 10명(83.3%)으로 월등히 많았고 B형은 2명(16.7%)이었으며, 추적검사에서 분획 양상이 변화된 경우는 6명(50%)이었고, 이들은 A나 B로 변화된 경우가 각각 2명(33.3%)이었다. 변화되지 않은 6명(50%)은 모두 A형으로 남아 있었다. 월별 PFGE 양상은 처음 배양시 집단클론 A, B, C, D형 4가지와 단독클론 세 가지형이었으나 감염 관리를 하면서 11월부터 집단클론 A, B 두 가지형으로 나타나는 양상을 보였고, A형이 더 우세하였다. 보균된 상태로 퇴원한 75명 중 외래 추적관찰이 가능했던 30명을 대상으로 대변 배양검사를 시행한 결과 모두 음성이 확인되었다. 결 론 : 다양한 클론의 균주에 의한 집단보균 상태는 감염 관리를 하면서 단일 클론으로 변화하는 양상을 보였고, A형이 우세한 것으로 보아 집단 보균을 일으킨 유형 중 주 집단 클론은 A형이었음을 알 수 있었다. ESBL 생성 K. pneumoniae 보균 상태는 중환자실내에 입원기간 중에는 거의 지속되지만, 지역사회로 복귀하면 전부 해제되는 것으로 보인다.

• Journal of Microbiology
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• 제33권2호
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• pp.132-135
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• 1995

To investigate the electrophoretic karytype of Fusarium oxysporum, intact chromosomal DNA was separated by pulsed-field gel electrophoresis (PEGE). DNA extraction from nulcei, mycelia and protoplasts were compared with one another and with the quantity and the suitability for PFGE separation in agarose gel. As a result, the most useful extracting method for intact DNA was found to be that from protoplasts. By varying the electrophoretic conditions, 8 chromosomal DNA bounds were resolved. Using the Schizosaccharomyces pombe and Saccharomyces cerevisiae as size standards, the size of Fusarium oxysporum chromosomes was estimated to range from approximately 0.6 Mb TO 6.7 Mb, and total genome size was 26.7 Mb. The suitability of electrophoretic karyotyping as a tool for strain characterization is discussed.