Yunsop Chong
Ann Clin Microbiol 1999 September, 2(2): 105-113. Published on 20 September 1999.
우리나라 임상미생물검사의 질이 선진국 수준을 따라잡게 되었다고 생각되던 시기에 경제적인 어려움을 당해 주저앉게 되었다. 이러한 시기에 이미 은퇴한 사람이 학회지에 글을 쓴다는 것은 귀한 지면을 낭비하는 비효율적인 일로 생각되었지만 요청을 수락할 수밖에 없었다. 글의 내용은 저자에게 맡겨졌는데, 저자는 국민들 중 100분 정도부터 세균검사를 해 왔기에 현재 처한 어려운 여건에서 세균검사를 어떻게 효율적으로 할 수 있을지를 생각해 보기로 하였다. 이 글에는 저자의 주장이 들어있음으로 반드시 따라야 할 권고는 아님을 밝힌다.
[in Korean]
Won Kil Lee, M.D.
Ann Clin Microbiol 1999 September, 2(2): 114-117. Published on 20 September 1999.
Biochips은 biologic chips, DNA chip 또는 microarrays라 명명되는데, 1990년대 초에 Affymetrix(Calif. USA)란 신약개발회사가 최초로 DNA microarray를 개발한 이래, 여러 연구가 검사에 이용될 수 있게 발전하고 있으나, 아직 실용화 단계에 있지 않다. 임상 검사로서 이용은 앞으로 5년 늦게는 10년 쯤 지나서나 후에야 가능하다는 예측이다[1].
가장 흔한 형태의 biochip은 유리나 크레딧 카드 크기(1cm²)의 판에 여러 프로브(probe)의 DNA를 부착시켜서, 전체 내·외적으로 하는 여러 가지 DNA가 hybridize되는 것을 검사하는 장치이다. 예를 들면, 한 개의 세포가 분열할 때 여러 개의 유전자가 작동하는 것을 검사하며, biochip은 한 번에 수천 가지의 생물학적 반응을 수행할 수 있으며, 이를 이용하여 여러 가지 병원체를 검출하거나 단백질을 이용하기도 하며, 부착된 프로브는 보통 20-25개의 짧은 DNA인 oligonucleotides가 mRNA에 역에 작용하여 cDNA로 변환되며 RNA 분석에 이용되고 있으며, 프로브가 10-20개 부착된 것이 있나한다. 10만개 까지 프로브가 빽빽하게 부착된 것도 있다.
[in Korean]
Chulhun Ludgerus Chang, M.D., Geun Am Song, M.D. and Bok-Kwon Lee, Ph.D.
Ann Clin Microbiol 1999 September, 2(2): 118-124. Published on 20 September 1999.
Shigella는 장내 세균과(Family Enterobacteriaceae)에 속하는 통성 혐기성 그람음성 간균으로, 모든 장내세균에 공통적인 포도당 발효능, nitrate 환원능을 갖고, cytochrome oxidase 음성이다. 대장균과 Shigella가 분리 배지에서 서로 다른 특징을 보이고, 대장균이 Shigella에 비해 생 화학적으로 여러 가지 활성을 보이는 경우가 많기 때문에 처음에는 서로 가까운 관계에 있는 세균으로는 생각하지 않았지만. DNA 교잡법에 의한 분석 결과 이 두 세균은 90% 정도의 DNA 연관성을 보여서 적어도 염색체 수준에서는 하나의 종에 속하는 세균으로 밝혀졌다. 외견상으로도 Shigella와 대장균은 구분하는데 매우 어려울 때 가 있다. 즉, Shigella도 일부는 포도당을 발효할 때 가스를 만들어내는 수가 있고. 대장균도 유당을 발효하지 못하거나 가스를 만들지 않거나 운동성이 없기도 하다. 또 대장균이 설사를 일으키기도 하기 때문에 병인성이 절대적인 가늠자가 되지도 못한다. 그래서 Shigella는 대장균 중에서 생화학적으로 활성이 적은 하나의 biogroup이라고 할 수 있다. 그러나 Shigella라는 이름이 우리에게 아주 익숙해져 있고 Shigella가 세균성 이질 (bacillary dysentery)이라는 특정한 질환을 잘 일으키며 대장균과 구별할 수 있는 특이 항혈청도 쉽게 구할 수 있기 때문에, 균종을 재분류했을 때 오는 혼란을 감수하면서까지 굳이 Shigella라는 이름 대신에 “biologically inactive E. coli” 따위 의 이름을 붙이지는 않는다. 그렇기는 해도 원래 Shigella는 병원성이 있고 E. coli는 위장관의 질환을 일으키지 않는 상재균이라는 관념적인 구분은 E. coli 0157:H7의 예에서 보듯이 절대적인 의미는 없다.
[in Korean]
Mi Ae Lee, M.D., Eun Sook Kang, M.D., Ki Sook Hong, M.D. and Wha Soon Chung, M.D.
Ann Clin Microbiol 1999 September, 2(2): 125-130. Published on 20 September 1999.
Background: Methicillin-resistant Staphylococcus aureus (MRSA) continues to be a major cause of nosocomial infection and a molecular typing is necessary for proper epidemiologic investigations of sources and modes of spread in an outbreak. An nosocomial outbreak of MRSA in a neonatal intensive care unit at Ewha Womans University Mokdong Hospital was suspected. To investigate the clonality of isolates and control the spread of nosocomial outbreak, we performed plasmid restriction analysis of MRSA isolates from patients and medical staffs.
Methods: We studied 7 MRSA strains (umbilicus 4, blood 1, urine 1 and pus 1) from patients in a neonatal intensive care unit and the MRSA strains from nares and hands surveillance cultures of 26 medical staffs (4 medical doctors and 22 nurses). All MRSA strains were tested for antimicrobial susceptibility and plasmid analysis after EcoRI restriction. We analyzed the plasmid patterns of MRSA isolated from patients and compared with those from medical staffs.
Results: Ten MRSA strains (from 7 nares and 3 hands) were isolated from surveillance cultures of 26 medical staffs. Seven out of 10 MRSA strains from medical staffs revealed identical pattern of antibiogram which was the same pattern in all 7 MRSA strains from seven patients. Plasmid restriction patterns were classified 6 groups from A to F showing 2-10 bands. Six out of 7 MRSA strains from the patients showed group A(A1 5, A3 1) and 5 out of 10 MRSA strains from the medical staffs showed group A(A1 1, A2 1, A3 2, A4 1) and remainders showed different plasmid restriction analysis patterns.
Conclusions: These results suggest that plasmid restriction analysis is a rapid, inexpensive, and good discriminating molecular typing of MRSA outbreak and is useful for the epidemiologic investigation of MRSA outbreaks in the clinical laboratory.
[in Korean]
Young Uh, Gyu Yel Hwang, In Ho Jang, Jong Sun Park, Oh-Gun Kwon, and Kap Jun Yoon
Ann Clin Microbiol 1999 September, 2(2): 131-134. Published on 20 September 1999.
Background: The erythromycin-resistance rate and phenotype distribution of Streptococcus pyogenes are quite different by geographical variation and study period. The aim of the present study was to determine the evolution of resistance to erythromycin and the frequency of erythromycin resistance phenotype of S. pyogenes isolated from Wonju Christian Hospital.
Methods: The minimal inhibitory concentrations (MICs) of erythromycin and clindamycin for 94 S. pyogenes isolated from clinical specimens between 1990 to 1998 were investigated. Double disk test of erythromycin (78µg) and clindamycin (25µg) were performed for 15 isolates of erythromycin-resistant S. pyogenes to evaluate the erythromycin resistance phenotype.
Results: The resistance rates of 94 isolates of S. pyogenes were 16%(15/94) to erythromycin and 4%(4/94) to clindamycin. The frequency of erythromycin resistance phenotype in decreasing order were M phenotype (47%), inducible resistance phenotype (40%), and constitutive resistance phenotype (13%). Erythromycin-resistant S. pyogenes did not exist until 1993, but was isolated since 1994, and ranged from 14.0% to 24.0% during the period of 1994-1998.
Conclusions: Our finding documents the emergence of high resistance rates to erythromycin in S. pyogenes at Wonju area since 1994. The M phenotype (47%) and inducible resistance phenotype (40%) account for the majority of erythromycin-resistant S. pyogenes.
[in Korean]
Young Uh, Jeong Seog Son, Gyu Yel Hwang, In Ho Jang, Kap Jun Yoon and Dong Min Seo
Ann Clin Microbiol 1999 September, 2(2): 135-143. Published on 20 September 1999.
Background: To access the accuracy and clinical usefulness of microplate identification (ID) system for the identification of Enterobacteriaceae, we compared microplate ID system with API 20E (bioMérieux, Marcy I’Etoile, France)
Methods: Ninety-two cultures of Enterobacteriaceae and one isolate of Aeromonas species were simultaneously identified by microplate ID system and the API 20E. Twenty biochemical tests used in microplate ID system were lactose, sucrose, and H₂S in Kigler’s iron agar media; indole, sucrose, raffinose, arabinose, trehalose, adonitol, dulcitol, sorbitol, cellibiose, methy-red, phenylalanine deaminase, ornithine decarboxylase, lysine decarboxylase, arginine dihydrolase, urease, and citrate in microplate; and oxidase test. The identification was obtained by considering percent likelihood (%ID), modal frequency and ID score method.
Results: Among the 92 cultures of Enterobacteriaceae and one isolate of Aeromonas species, agreement rate of identification according to the %ID between microplate ID system and API 20E were 90.3% to the species level and 97.8% to the genus level.
Conclusions: For the identification of clinical Enterobacteriaceae isolates, the microplate ID system compares favorably with API 20E in identification accuracy and have the advantage of cost-saving and easy to use.
[in Korean]
Youn Mi Choi, M.D. and Myung Hee Lee, M.D.
Ann Clin Microbiol 1999 September, 2(2): 144-151. Published on 20 September 1999.
Background: The recently developed nucleic acid amplification methods may provide us with very sensitive, specific and rapid tests for the detection of M. tuberculosis. So the aim of this study was to compare the commercial Amplicor M. tuberculosis kit and our in-house polymerase chain reaction (PCR) with the conventional culture and direct AFB staining method.
Materials and Methods: Among the total of 2,340 clinical specimens, 1,314 sputum samples were tested for the presence of M. tuberculosis by Amplicor PCR and 1,026 sputum samples were tested by in-house PCR performing with resin matrix preparation and DNA extraction, synthesized primer pair, detection using agarose gel electrophoresis.
Results: One hundred-seventeen specimens were positive by Amplicor PCR, 105 were positive by in-house PCR, 185 were positive by culture. The sensitivity of the Amplicor PCR for all of the specimens and for smear-positive and smear-negative specimens was 92.9%, 97.9% and 88.2%, respectively after discrepant analysis. The sensitivity of the in-house PCR for all of the specimens and for smear-positive and smear-negative specimens was 80.0%, 93.6% and 65.5%, respectively after discrepant analysis. The specificity of the Amplicor PCR and in-house PCR for all of the specimens was 97.9% and 99.0%, respectively.
Conclusions: Amplicor PCR was more sensitive than in-house PCR, but there was another problem such as high false positive rate and high cost. So PCR may certainly become very useful in microbiological laboratories if PCR method is selected according to the laboratory conditions.
[in Korean]
Jung Oak Kang, M.D., Sun-E Kim, M.D., Think-You Kim, M.D., Ile Kyu Park, M.D. and Tae Yeal Choi, M.D.
Ann Clin Microbiol 1999 September, 2(2): 152-157. Published on 20 September 1999.
Background: Rotavirus activity in Korea has been reported beginning in October, peak in November, continuing in winter and ending in spring. But the peak month and the incidence of rotavirus seems to be changed recently. So we investigated the trends of rotavirus activity for the last 10 years in Hanyang University Hospital (HUH). Also latex agglutination test was compared with automated enzyme-linked fluorescent immunoassay for the detection of rotavirus in stool specimens.
Methods: Stool specimens (3,636 from HUH, 1989-1998; 1,171 from Hanyang University Kuri hospital, HUKH, 1996-1998) from pediatric patients with acute diarrhea were tested for rotavirus,. Sixty specimens were tested by latex agglutination test (Slidex Rota-kit 2, bioMerieux Vitek, France) and enzyme-linked fluorescent immunoassay (VIDAS Rotavirus, bioMerieux Vitek, France) according to the instructions from the manufacturer.
Results: The annual incidence of rotavirus diarrhea from 1989 to 1998 was 47%, 32%, 33%, 25%, 26%, 24%, 24%, 17%, 17%, 14%, respectively. Positive rate of rotavirus was 25% for the 10 year period in HUH, 20% for the recent 3 years in HUKH. Peak month was November (46%) in the first 5 year, but November incidence decreased to 17% in the last 5 year, and the peak moved to January, February, and March (34%, 35%, 33%, respectively). Epidemic period was from October to February during the first 5 year, but from December to April during the last 5 year period. The agreement rate of the two methods was 90% and VIDAS Rotavirus showed significantly higher sensitivity compared to Slidex Rota-kit 2.
Conclusions: The incidence of rotavirus diarrhea decreased gradually for the last 10 years and the peak month of rotavirus activity was changed from November to January, February, and March. The VIDAS Rotavirus was more sensitive than the Slidex Rota-kit 2 for the detection of rotavirus in stool.
[in Korean]
Yoon Hee Kang, M.D., Soo Jin Choi, M.D., Sang Hyun Hwang, M.D., Young Wook Cho, M.D., Duck-Hee Kim, M.T., Mi-Na Kim, M.D. and Chik Hyun Pai, M.D.
Ann Clin Microbiol 1999 September, 2(2): 158-166. Published on 20 September 1999.
Background: Escherichia coli and Klebsiella pneumoniae resistant to 3rd generation cephalosporin have been reported with increasing frequency in tertiary-care hospital in Korea. MicroScan Neg Combo Panel Type 21 (Type 21) contains a 1 µg/mL cepfoxodime (POD) in addition to other screen wells containing ceftazidime, cefotaxime, ceftriaxone, and aztreonam, which are designed for detecting extended-spectrum β-lactamase (ESBL)-producing E. coli and Klebsiella species. We evaluated the Type 21 panel for its ability to detect ESBL.
Methods: From November to December in 1998, 496 E. coli and 326 K. pneumoniae strains isolated from clinical specimens were tested with Type 21 panel. The isolates flagged as ESBL producers by the panel were confirmed by the double disk synergy test (DDS). To evaluate the specificity of POD, β-lactamases of 54 E. coli and 20 K. pneumoniae strains that were flagged by POD only from January to May 1999 were analyzed by isoelectric focusing(IEF).
Results: 75/496 (15%) E. coli and 68/326 (21%) K. pneumoniae were flagged as ESBL producers by Type 21 panel. Of those, 94 isolates including 38/75 (51%) of E. coli and 56/68 (82%) of K. pneumoniae were positive for DDS. Among the 94 ESBL producers, all were detected by POD, 84% by cefotaxime, 85% by ceftazidime, 84% by ceftriaxone, and 86% by aztreonam. The 74 strains that were flagged as ESBL producers by POD screen well only were mostly DDS-negative, cefoxitin- resistant and showed β-lactamases with pIs of 5.4 and 7.6 or no band, which could be interpreted as the presence of TEM-1 or SHV-1 type β-lactamases and/or basal AmpC β-lactamases, not ESBL.
Conclusion: MicroScan Neg Combo Panel Type 21 was able to detect a greater number of ESBL producers by inclusion of POD in its screening well. However, the specificity of POD was compromised by flagging a significant number of DDS negative strains. We conclude that the isolates with reduced susceptibility to 3rd generation cephalosporins as well as POD can be reported as ESBL-producers and those resistant to POD only should be confirmed by DDS.
[in Korean]
Wonkeun Song, M.D., Jin Tae Suh, M.D., Jung-Oak Kang, M.D., Sun-E Kim, M.D., Myung Jae Park, M.D., Hee Chul Park, M.D., Yong Kyun Roh, M.D., and Dong Hun Shin, M.D.
Ann Clin Microbiol 1999 September, 2(2): 167-171. Published on 20 September 1999.
Background: Diagnosis of tuberculosis is more complicated because of low sensitivity and time-consuming procedures of the conventional diagnostic methods as well as nonspecific clinical features. Recently the serologic diagnosis of tuberculosis has been reported as one of rapid sensitive and specific methods. We evaluated the ability of a rapid ICT Tuberculosis assay (AMRAD/ICT Diagnostics, Sydney, Australia) to detect pulmonary tuberculosis.
Methods: ICT Tuberculosis assay was performed to the sera from 50 patients with pulmonary tuberculosis (24 patients with smear positive, 26 patients with smear negative) and 105 controls (48 patients without tuberculosis, 57 healthy controls).
Results: Antibodies were detected in 22 of 24 (92%) smear positive patients and 22 of 26 (85%) smear negative patients who had been clinically diagnosed as having active pulmonary tuberculosis. Two (4.2%) out of 48 patients without tuberculosis and 1 (1.8%) out of 57 healthy controls had a positive antibody response. The overall sensitivity, specificity, and positive and negative predictive value of the ICT Tuberculosis assay were 88%, 97%, 94%, and 94%, respectively.
Conclusions: The ICT Tuberculosis assay was not only sensitive and specific but also rapid and simple. This assay will be useful as a diagnostic method of pulmonary tuberculosis in combination with sputum smear and X-ray.
[in Korean]
Eui-Chong Kim, Jung-Hee Lee, Hyun-Jin Jung, and Young-Joon Lee
Ann Clin Microbiol 1999 September, 2(2): 172-176. Published on 20 September 1999.
Background: Hand-foot-mouth disease (HFMD) is mainly caused by the infection of coxsackievirus A16. But recently several epidemics of HFMD with meningitis or myocarditis due to enterovirus 71 have been reported in Southeast Asia. It was necessary that the possibility of enterovirus 71 epidemic in Korea should be ruled out. This study was designed for the determination of causative agents of HFMD in Cheju province in the spring of 1998.
Methods: Serum specimens were collected from 45 pediatric patients with HFMD at Cheju Hankook Hospital in March and April, 1998. Virus isolation was performed with RD cell culture through up to three passages. Reverse transcription-PCR and nucleotide sequencing were performed by the method of Oberste et al. (J Clin Microbiol 1999;37:1288-93). The serotypes of viral isolates were determined by BLAST program of National Center for Biotechnology Information, U. S. A.
Results: Virus could be isolates from 4 patients, whose age was ranged from 11 months to 3 years. All of 4 viral isolates showed about 430-bp product of RT-PCR using primers 011 and 012. The serotype showing the highest similarity with the nucleotide sequences of all of these viral isolates was coxsackievirus A16.
Conclusions: The causative enteroviral agent of HFMD in Cheju province in the spring of 1998 was coxsackievirus A16. We could not detect enterovirus 71 from the patients’ sera in Cheju Province in the spring of 1998.
[in Korean]
Yong-Wha Lee, M.D., Myung-Hyun Nam, M.D., Jang Ho Lee, M.T. and Nam Yong Lee, M.D.
Ann Clin Microbiol 1999 September, 2(2): 177-181. Published on 20 September 1999.
Background: Early detection and treatment of cytomegalovirus (CMV) infection is very important because CMV infection is a major cause of morbidity and mortality after organ transplantation. CMV antigenemia assay has been reported to be very sensitive and specific for detection of CMV infection among many laboratory methods. However, there is no single method correlated well with the infection state up to now. We compared the results of SHARP Signal System Assay (Digene, USA) using PCR and hybridization with those of CMV antigenemia assay (Clonab CMV-kit; Biotest AG, Germany) to evaluate their clinical usefulness.
Methods: We performed SHARP Signal Assay on whole blood samples of 125 from 56 transplanted patients submitted for CMV antigenemia at Samsung Medical Center. We compared the results with those of CMV antigenemia and evaluated the correlation with CMV disease state.
Results: Fifty six patients were classified as three groups; 43 patients with no evidence of CMV infection, four patients with CMV infection and nine patients with CMV disease. Twenty four cases (19.2%) showed discrepant results between the two methods. Of the 22 cases showing positive only by SHARP Signal Assay, two cases were proved to be CMV disease, 12 cases were on antiviral treatment and remaining cases had no evidence of infection. Two cases showing positive only by CMV antigenemia were confirmed to be CMV disease. For CMV disease, the sensitivity of SHARP Signal Assay and CMV antigenemia were 85.7% and 90.5%, respectively and the specificity of them were 73.1% and 93.3%, respectively.
Conclusions: CMV antigenemia is thought to be useful for early diagnosis and follow-up of antiviral treatment as a quantitative and highly specific method, and SHARP Signal Assay can be used as a complementary method because it correlates well with disease state.
[in Korean]
Jae Lim Chung, M.D., Young Ah Kim, M.D., Hee Bong Shin, M.D., Jeong Won Shin, M.D., Kyungwon Lee, M.D., Yunsop Chong, Ph.D., Jang Hyeon Park, Ph.D. and Won Bae Kim, Ph.D.
Ann Clin Microbiol 1999 September, 2(2): 182-193. Published on 20 September 1999.
Background: β-lactam antibiotics are one of the most frequently used antimicrobial agents. However, with the increase of β-lactamase-producing bacteria, penicillins and 1st generation cephalosporins have become less useful. Cefatrizine and clavulanic acid combination (CTCA) was developed to restore the activity. The aim of this study was to determine the activities of CTCA against major recent clinical isolates.
Methods: Aerobic and anaerobic bacteria tested were isolated from clinical specimens in Severance Hospital during 1996 to 1999. Antimicrobial susceptibility was determined by the NCCLS agar dilution methods.
Results: MICs of cefatrizine (CT) and CTCA were similar for methicillin-susceptible Staphylococcus aureus, Streptococcus pyogenes and S. pneumoniae. For Moraxella (Branhamella) catarrhalis, MIC90 of CTCA was 1 µg/mL, which was 1/8-fold lower than that of cefatrizine. MIC90s of CTCA for Escherichia coli and Klebsiella pneumoniae were 4 µg/mL and 8 µg/mL, respectively, which were 1/4- to 1/16-fold lower than those of CT. However, it was less active against Citrobacter freundii, Enterobacter cloacae and Serratia marcescens. Against Bacteroides fragilis group organisms, it showed good activities similar to those of other β-lactam and β-lactamase inhibitor combinations.
Conclusions: CTCA showed good antimicrobial activities against M. (B.) catarrhalis, Haemophilus influenzae, Neisseria gonorrhoeae, extended spectrum β-lactamase-producing E. coli and K. pneumoniae, Proteus vulgaris and B. fragilis. In conclusion, it would be useful for the treatment of infections due to those organisms, and for the empirical treatment of respiratory and urinary tract infections.
[in Korean]
Sean Mi Song, M.D., Jang Ho Lee, M.T. and Nam Yong Lee, M.D.
Ann Clin Microbiol 1999 September, 2(2): 194-198. Published on 20 September 1999.
BACKGROUND: Enterococci exhibit intrinsic resistance or high-level minimum inhibitory concentration (MIC) to β-lactams than other streptococci. This appears to be due to low affinity of penicillin-binding proteins and rarely production of β-lactamase, which gives the reason of testing β-lactamase for blood and cerebrospinal fluid isolates. Ampicillin is more effective than penicillin in vitro, and MIC of ampicillin is generally 1 dilution lower than that of penicillin. The purpose of this study is to detect β-lactamase producing enterococci and to compare MICs of ampicillin and penicillin by Vitek system (bioMerieux, Hazelwood, MO, USA) with those by agar dilution method.
METHODS: We collected 110 isolates of Enterococcus faecalis and 51 isolates of E. faecium from clinical specimens in 1998. MICs of antibiotics were determined by agar dilution method and Vitek system. We also performed β-lactamase test by the Cefinase (Becton Dickinson, USA) for 512 isolates of E. faecalis and 189 isolates of E. faecium collected in 1998.
RESULTS: The most common sites of isolates were blood, bile, surgical/traumatic wounds, closed and open pus and urine. MICs of ampicillin were 1 to 2 dilution lower than those of penicillin for E. faecalis (P=0.03). But there were no significant differences in MICs for E. faecium (P=0.19). Five isolates (4 E. faecalis and 1 E. faecium) were susceptible to ampicillin but resistant to penicillin. There were no β-lactamase producing enterococci among 701 isolates tested.
CONCLUSIONS: MIC by Vitek system tends to be 1 to 2 dilution lower than MIC by agar dilution method to β-lactams, and MIC of ampicillin is 1 to 2 dilution lower than MIC of penicillin, which could result in discrepancy in interpretation of susceptibility tests. A β-lactamase test for enterococci is not recommended for routine test in Korea.
[in Korean]
Sean Mi Song, M.D., Jang Ho Lee, M.T. and Nam Yong Lee, M.D.
Ann Clin Microbiol 1999 September, 2(2): 199-206. Published on 20 September 1999.
Background: The incidence of reported nontyphoidal Salmonellosis has increased during last decade in Korea. Salmonella typhimurium and Salmonella enteritidis are two major serotypes in nontyphoidal Salmonella. To determine the nature of potential outbreak S. typhimurium infection in a community, we retrospectively evaluated clinical and epidemiologic features of S. typhimurium infections and performed pulsed-field gel electrophoresis (PFGE) to investigate a genetic relatedness of S. typhimurium isolated in Guro Hospital.
Methods: From May 1998 to April 1999, a total of 20 S. typhimurium strains were isolated from 18 patients. PFGE patterns were analyzed for 20 S. typhimurium strains. Clinical and epidemiological features were evaluated from their medical records.
Results: Seventy two percent (13/18) were acute gastroenteritis, and 11% (2/18) were enteric fever and 16% (3/18) were intussusception. Seventy eight percent (14 of 18) of patients were six years old or less than. There were two major type (A, B) on PFGE analysis. Eight of 20 strains showed identical PFGE type (A1). Eleven strains were subtypes of A1. One strain showed different type (B). Similarity coefficients between A1 and its subtypes were all over 0.765 and they showed close genetic distance on dendrogram. Antibiogram of A1 eight strains were various.
Conclusions: High genetic relationship among 20 S. typhimurium strains for a year in Guro area indicates that they were possibly originated from one clone and that there might be a common source of infection. More efforts should be directed toward the epidemiological investigation of the cases to detect outbreaks and prevent further spread of the infection.
[in Korean]
Hyun Lim, M.D., Dal Sik Kim, M.D., Hye Soo Lee, M.D. and Sam Im Choi, M.D.
Ann Clin Microbiol 1999 September, 2(2): 207-211. Published on 20 September 1999.
Thelazia callipaeda is a slender, long, and cylindrical nematode which parasitizes in the conjunctival sac of human and causes conjunctivitis. The animals such as the dog, rabbit, horse, deer, and cow were revealed as its reservoir and some species of the fly suspected as its vector. We experienced a case of T. callipaeda isolated from human conjunctival sac of a 41-year old man who lived in Wanju-gun, Chonbuk province and raised the dogs. He complained of an irritation, itching and foreign body sensation on his right eye and the two worms were picked out of his right eye by forceps from conjunctival sac. General features of the worms were ivory colored and slender. Two worms were 15.2mm and 15.8mm in length and both have less than 1.0mm in maximum width. Microscopically, both of the worms were female. The vulva opening of the worms located anterior to esophago-intestinal junction. The uterus filled with the eggs and larvae encysted with oval membrane. The buccal cavity in head portion was tetrazoid and connected with well-developed esophagus. At the tails of the worms, anus and papillae were observed. Characteristic compact cuticular transverse striations were identified on the whole body surface.
[in Korean]
Sung Hee Han, M.D., Mi Ae Lee, M.D. and Wha Soon Chung, M.D.
Ann Clin Microbiol 1999 September, 2(2): 212-215. Published on 20 September 1999.
Fungi have been recognized as a significant cause of external otitis and it may be the primary pathogen or be part of a mixed infection. In the immunocompromised host, fungus is capable of producing infection in inner ear or middle ear. Otomycoses are most frequently caused by Aspergillus spp. and Candida spp. There are few reports that Aspergillus species other than A. fumigatus, A. niger and A. flavus have caused chronic otitis media. We report two cases of chronic otitis media caused by Aspergillus terreus in Korea. One case is a 7-year-old girl who had recurrent serous otorrhea and otalgia for 4 years, was reattended otolaryngology clinics with otorrhea of 3 days durations and another is a 6-year-old girl who had serous otorrhea for 2 months and 3 day fever, was attended otolaryngology clinics with them. Microscopic appearance and colony morphology from ear discharge cultures revealed A. terreus. The infection responded well to topical ketoconazole therapy. This report should help to raise medical personnel’s awareness of such human opportunistic fungal ear infections.
[in Korean]
Jang Su Kim, M.D., Chang Kyu Lee, M.D., In Bum Suh, M.D., Hyeun Ah Lee, Young Kee Kim, M.D. and Kap No Lee, M.D.
Ann Clin Microbiol 1999 September, 2(2): 216-219. Published on 20 September 1999.
Purpura fulminans is a potentially disabling and life-threatening disorder characterized by acute onset of progressive cutaneous hemorrhage and necrosis on distal extremities, and disseminated intravascular coagulopathy. We experienced a case of purpura fulminans due to Streptococcus pneumoniae. A 42-year-old woman presented with skin petechiae, ecchymosis and gangrene on distal extremities with laboratory evidence of DIC. The latex agglutination test with CSF was positive at Streptococcus pneumoniae. To our knowledge, this is the first report of purpura fulminans caused by Streptococcus pneumoniae in Korea.
[in Korean]
Jeong Won Shin, M.D., Kyoung Ho Roh., M.D., Kyungwon Lee, M.D. and Yunsop Chong, Ph.D.
Ann Clin Microbiol 1999 September, 2(2): 220-224. Published on 20 September 1999.
Group B Streptococcus (GBS, S. agalactiae) is known to be the leading cause of neonatal sepsis and meningitis and the infection has been increasingly noted in adults, particularly in those with underlying diseases. Penicillin G is the drug of choice for GBS infection. However, the MIC of penicillin for GBS is greater than that for S. pyogenes. Therefore some GBS infections may be difficult to be treated. However, in Korea, our knowledge on GBS infection is limited. We observed 7 cases of GBS bacteremia during 1993-1996 in a hospital. Of the 7 patients, 3 were less than one month of age with no known underlying disease and 4 were adults with liver cirrhosis or malignancy. One adult patient developed disseminated intravascular coagulopathy and expired. Among the GBS isolates, 4 were serotype III and 3 were Ib. All of the isolates were susceptible to ampicillin, teicoplanin and vancomycin, but most were intermediate or resistant to clindamycin, erythromycin or tetracycline. It is concluded that GBS also cause severe infections in adults with underlying diseases and the serotypes III and Ib may be more virulent than other serotypes. Early detection and antimicrobial susceptibility test of GBS from severe infection may be necessary for the proper treatment of the patients.
[in Korean]
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