• 대한미생물학회지
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• 제22권1호
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• pp.55-59
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• 1987

Salmonella typhi infection, which was the most frequent enteric infection in Korea, has been decreasing, while the infection of other serogroups of Salmonella has been increasing since the later part of 1970s. In 1986, the number of serogroup B isolated by us increased to 46, which corresponds 21.1% of all enteropathogenic bacteria isolated from stool specimens. Salmonella isolates resistant to antimicrobial agents were extremly rare in Korea, in the 1970s. However, 7 of 13 serogroup B isolates showed resistance to ampicillin or to chloramphenicol in 1984. Among the serogroup B isolates in 1986, 71.7% and 69.6% were resistant to ampicillin and to chloramphenicol respectively. The minimum inhibitory concentrations of ampicillin and chloramphenicol against these isolates were >$128\;{\mu}g/ml$ and $128\;{\mu}g/ml$ respectively.

• 대한수의학회지
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• 제48권2호
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• pp.145-151
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• 2008

This study was conducted to investigate biochemical properties and O group serotypes of pathogenic 203 Escherichia (E.) coli isolates from poultry with collibacillosis in Korea during the period from April 2003 to December 2005. Biochemical and fermentative properties of 203 isolates of E. coli tested were in accordance with Cowan and Steel's classification standard. One hundred and forty one isolates (69.5%) could be classified into a total of 20 O serotypes. Among them, the predominant O groups were O78 (32.5%), O88 (7.8%), O15 (6.8%), O141 (6.4%), and O158 (3.0%) in decreased order. Other infrequently encountered serogroups included : O8 (2%), O161 (2%), O20 (1.5%), O125 (1.5%), O2 (1%). And O6, O18, O24, O46, O76, O109, O119, O138, O139 and O148 had a frequency of 0.5%, respectively. Sixty two isolates (30.5%) were non-typeable with standard 173 O antisera used in this study.

• 대한수의학회지
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• 제39권4호
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• pp.743-750
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• 1999

Bovine viral diarrhea viruses (BVDVs) were isolated from cattle with respiratory and diarrhea signs as well as persistently infected cattle. These isolates were analysed serologically to characterize serogroups and to compare serological relationship with reference viruses of type I and II. Most isolates from calf diarrheal cases and persistently infected individuals showed a significant difference in cross-neutralization test with the viruses isolated from nasal discharges showing severe respiratory signs. Serologically most of the commercial vaccine strains could be classified into classical BVDV (type I) such as NADL strain. This serological difference among BVDV isolates suggested the need for new vaccines to protect cattle from both respiratory and enteric BVDV infections in field. The immunogenicity of BVDVs which showed a good propagation capability in MDBK cells and high rates of neutralizing activity (isolate : KD26-1, PHG, B5 and 95002) against all viruses used in this study, was confirmed in guinea pig when treated as single or combined groups.

• 한국동물위생학회지
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• 제37권3호
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• pp.165-171
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• 2014

This study was conducted to investigate the species-specific gene detection, capsular serogroup and antimicrobial resistance pattern of Pasteurella multocida isolated from pneumonic lung lesion of swine in Gyeongbuk province. P. multocida isolates were typed for capsular serogroups by polymerase chain reaction. Of the 32 strains, 28 (87.5%) were typed serotype A, 3 (9.3%) were typed serotype D, and 1 strain was unknown (3.1%), respectively. In antimicrobial agents resistance test, almost of strains were susceptible to amoxicillin (100%), enrofloxacin (96.9%), ampicillin (93.8%), florfenicol (90.6%), chloramphenicol (90.6%) and were resistant to streptomycin (71.9%), spectinomycin (56.3%). All strains were resistant to clindamycin, erythromycin and lincomycin.

• 대한수의학회지
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• 제58권1호
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• pp.61-64
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• 2018

Eight rabbits exhibited head tilt and subsequently died. At necropsy, three rabbits had crusty deposits in ears and four had reddish lungs. The main histopathological features were severe diffuse suppurative meningoencephalitis (75.0% of rabbits), fibrinopurulent pneumonia (37.5%), and otitis externa (37.5%). Pasteurella multocida (P. multocida) was isolated from brains, ears, and lungs. The capsular serogroups of the isolates were untypable. Based on histopathological features and bacterial analysis results, the rabbits were diagnosed as P. multocida infection. P. multocida infections might result in considerable economic loss in commercial rabbit production facilities in Korea.

• 한국미생물·생명공학회지
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• 제48권2호
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• pp.121-128
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• 2020

Diarrhea is a major public health concern associated with pathogenic Escherichia coli infections. Food-borne pathogenic E. coli can lead to large diarrheal outbreaks and hence, there is a need to estimate the frequency of pathogenic E. coli load in the various types of meat available in markets. In the present study, we classified and characterized diarrheagenic E. coli isolates collected from 399 raw meat samples from retail sources in Korea. Shiga toxin-producing E. coli (STEC) were detected in 11 (9.7%) samples, including nine strains (8.0%) in beef and two strains (1.8%) in chicken. The frequency of the detected virulence markers were as follows: astA, 28.3%; escV,18.6%; eaeA,17.7%; ent, 7.0%; EHEC-hly, 4.4%; stx1, 3.5%; and stx2, 3.5%. We did not observe any typical EPEC, EIEC, or ETEC virulence determinants in any of the samples. The STEC serotype O26 was detected in one sample, but no other serogroups (O91, O103, O128, O157, O145, O111, and O121) were found. Further research is needed to better understand the virulence mechanism of STEC serotypes, their ecology, and prevalence in animals, food, and the environment. These results will help improve risk assessment and predict the sources of food poisoning outbreaks.

• 한국동물위생학회지
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• 제16권1호
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• pp.41-50
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• 1993

This study was undertaken the bioserotype and drug resistance of Salmonella and Escherichia coli isolated from feces for the prevention and treatment of salmonellosis and colibacillosis in zoological animals. The results obtained from the research were as follows 1. Salmonella were isolated 19, or 4.7% from 408 samples and E. coli were isolated 12, or 40.0% from 30 diarrheal samples. 2. The biotypes in 19 Salmonella were Subspecies 1. 3. The serogroups of Salmonella isolated were 47.4% in B group, 31.6% in C, 5.3% in D and 15.8% in other, and serotype of E. coli was 100% in 0127a. 4. The antibiotic resistance of Salmonella and E. coli isolated were 13, or 68.4% and 7, or 58.3% strains, respectively 5. The multiple resistant patterns of antibiotics in Salmonella were 2drugs- and 3 drugs-resistance 30.8%, respectively, and those in E. coli were mono drug-, 2 drugs- and 7 drugs-resistance 28.6%, respectively. 6. The transferred rate of resistance to recipients (E. coli ML 1410 NA$^{r}$ ) in Salmonella was 38.5%, but that in E. coli was 71.4%.

• Clinical and Experimental Pediatrics
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• 제45권3호
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• pp.346-353
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• 2002

목 적: 폐구균은 영유아와 소아에서 세균성 뇌막염, 중이염, 부비동염 등의 주요한 원인균으로 혈액과 중추 신경계로 전파가 잘되며 사망률이 높다. 최근 전 세계적으로 페니실린은 물론 여러 항균제에 내성을 보이는 폐구균이 증가하는 추세여서 의료계에 큰 문제로 대두되고 있다. 이에 폐구균의 상기도 보균율과 항균제 내성 양상에 대한 정확한 파악이 임상에서 경험적 항균제 선택에 많은 도움을 줄 수 있으므로 연구자는 서울 지역 유아원에 다니는 5세 이하 소아에서 폐구균의 상기도 보균율과 혈청군 및 분리된 균의 항균제 감수성에 대해 연구하였다. 방 법: 1998년 3-6월까지 서울지역의 5개 유아원에서 5세 이하 소아 209명을 대상으로 소독된 면봉으로 이들의 구인강 점막을 세게 문질러 검체를 얻고 이 중 63명에서 폐구균을 분리하였다. 이 때 폐구균은 형태, optochin 검사, 그람 염색, 및 catalase 검사로 동정하였다. 이 중 구인강에서 분리된 폐구균 59균주를 대상으로 penicillin, cefotaxime, vancomycin, chloramphenicol, trimethoprim/sulfamethoxazole, tetracycline, erythromycin, oxacillin, ciprofloxacin에 대해서 감수성 검사를 시행하였다. 폐구균의 혈청군은 48균주에서 검사가 가능하였으며 group specific antisera를 이용한 Quelling 반응으로 미국의 Birmingham에 있는 University of Alabama에서 시행하였다. 결 과: 전체 소아의 구인강에 존재하는 폐구균의 보균율은 30.1%이었으며, 연령별로는 1세 미만은 없었으며, 1세가 25%, 2세가 16.1%, 3세가 31%, 4세가 34.4%, 5세가 33.3%였다. 폐구균에 대한 항균제 내성 양상을 보면 tetracycline은 89.8%, erythromycin은 76.3%, oxacillin은 72.4% trimethoprim-sulfamethoxazole은 58.6%, chloramphenicol은 22.0%, cefotaxime은 6.7%의 내성율을 보였으며, vancomycin에 는 모두 감수성을 보였다. 페니실린 내성율은 66.0% 이었고 페니실린 감수성 균주와 내성 균주에서의 타 항균제에 대한 내성 비교시 페니실린 감수성 균주의 경우 cefotaxime, vancomycin, ciprofloxacin 등에 모두 감수성이 있었으며, tetracycline, trimethoprim-sulfamethoxazole, erythromycin, oxacillin에 21-75%의 내성을 보였다. 반면 페니실린 내성 균주의 경우 cefotaxime에 58.3%의 내성을 보였으며, tetracyclin, oxacillin, erythromycin, trimethoprim-sulfamethoxazole에 각각 94.8-97.4%의 내성을 보여 대체로 페니실린 감수성 균주는 다른 항균제에도 감수성을 보였으나, 페니실린 내성 균주는 타항균제에도 내성을 보이는 경우가 많았다. 페니실린 다제 내성균주는 76.3%였다. 혈청군 검사가 가능하였던 49균주 중 혈청군 19가 12례로 가장 많았고 6이 9례, 3이 8례, 23이 6례, 29가 5례, 그밖에 13, 14, 16, 22, 31 및 34형이 있었다. 혈청군에 따라서 페니실린 내성에도 차이를 보여 혈청군 19, 23 및 29에서는 모두 감수성이 없었으며 혈청군 6에서는 1균주에서 감수성이 있었으나 혈청군 3에서는 7균주에서 감수성이 있어 혈청군에 따라 penicillin에 대한 감수성에 차이를 보여주었다. 결 론 : 유아원 소아 중 30.1%의 구인강에서 폐구균이 분리되었고, 분리된 폐구균은 페니실린을 비롯한 여러 항균제에 높은 내성율을 보였다. 구인강에서 분리된 폐구균 중 혈청군 19가 가장 많았고 6, 3, 23, 29가 대부분을 차지하였으며 폐구균은 혈청군에 따라서 페니실린 내성에 차이를 보여 주었다. 폐구균의 내성율을 줄이기 위해서는 우선 항균제의 적절한 사용과 유아원과 같은 집단시설의 환경 개선, 2세 미만 소아에게 적절한 백신 개발 및 예방접종 등 적극적인 노력이 수반되어야 할 것으로 생각된다.

• 한국환경보건학회지
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• 제44권2호
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• pp.133-142
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• 2018

Objectives: The pathogenic Vibrios genus denotes halophilic bacteria that are distributed in aquatic environments, including both sea and freshwater. Vibrio cholerae, Vibrio vulnificus, and Vibrio parahaemolyticus are the most important species since they can be potent human pathogens and leading causes of septicemia, wound infections, and seafood borne gastroenteritis. The recent emergence of a potential pandemic clone, V. cholera serotype O1 and the cholera outbreak in South Korea in 2016 indicates the importance of consistent surveillance of pathogenic Vibrio genus within coastal areas. Methods: The present study was undertaken to determine where and how vibrios live in the aquatic environment adjacent to coastal areas of South Korea. For this survey, a total of 838 samples were obtained at 35 different sites in South Korean coastal areas during the period from January 2016 to December 2016. Pathogenic vibrios was determined using the real-time PCR method, and its clones were isolated using three selective plating media. We also monitored changes in seawater and atmospheric temperature, salinity, turbidity, and hydrogen ion concentration at the collection points. Results: The total isolation rates of V. vulnificus, V. cholera (non-pathogenic, non-O1, non-O139 serogroups), and V. parahaemolyticus from seawater specimens in 2016 were 14.2, 13.48, and 67.06%, respectively. Conclusions: The isolation rates of pathogenic vibrios genus showed a positive correlation with temperature of seawater and atmosphere but were negatively correlated with salinity and turbidity.

• Journal of Microbiology and Biotechnology
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• 제19권10호
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• pp.1238-1243
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• 2009

The susceptibilities of major enterohemorrhagic Escherichia coli (EHEC) strains to antimicrobial agents and the cytotoxicity of these agents were examined using a total of 38 strains of E. coli O26, O111, and O157, which are the major serogroups of EHEC. Among the 38 strains, 35, 36, and 36 were susceptible to amikacin, imipenem, and norfloxacin, respectively. These antimicrobial agents were further examined to determine their cytotoxicity on Vero cells as well as their effect on the release of Shiga toxins along with trimethoprim/sulfamethoxazole. Each of the E. coli O26, O111, and O157 strains containing both the stx1 and stx2 genes were grown in the absence or presence of these agents at 1/4 minimal inhibitory concentration for 6 h, 12 h, and 18 h. At the concentrations used in this study, none of the agents significantly altered cell count compared with the control group. The level of cytotoxicity in the imipenem group was lower at 12 hand 18 h than their respective controls. In contrast, the level of cytotoxicity in cultures treated with trimethoprim/sulfamethoxazole, norfloxacin, and amikacin was increased. The strains were also examined for the release of Shiga toxins 1 and 2 following treatment with the agents, which were measured by the reversed passive latex agglutination (RPLA) method. The RPLA assay showed a suppression of release of Shiga toxin 2 in the strain cultures containing imipenem. These results indicate that imipenem may be a safe and effective agent for inhibition of these bacteria, which has clinical implications for the treatment of EHEC infections.