• Pediatric Infection and Vaccine
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• v.13 no.2
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• pp.99-105
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• 2006

Purpose : The serotyping results of the Quellung reaction was compared with the newly developed multiplex latex assay and the sensitivity of the Quellung reaction was compared. Methods : We checked the serotypes of 35 samples obtained from patients treated at Yonsei University Medical Center using the multiplex latex bead method and compared the results with the serotypes previously obtained via the Quellung reaction. Results : A decrease in the mean fluorescence was detected in the samples tested with the multiplex assay. Seventeen samples out of the 27 samples agreed to the results of the Quellung assay. We were only able to confirm the concordance of 11 serotypes out of 14 serotypes available. Conclusion : The Quellung reaction is time consuming procedure and prone to errors even with expertise in the procedure, and other alternate methods in serotyping have been investigated to overcome these problems. The newly developed multiplex latex bead assay can test more samples at the same time and has a higher degree of sensitivity. A large scale trial is required to test the sensitivity of the new assay across various serotypes along with efforts to increase the sensitivity of the Quellung assay. The preliminary data suggests that this method may be widely used.

• Pediatric Infection and Vaccine
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• v.13 no.2
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• pp.89-98
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• 2006

Purpose : The prevalence of serotypes can be changed with respect to age of the patients, regions and times of the surveillance. The aim of this study is to analyze changes in serotype distribution of pneumococcal isolates from Korean pediatric patients. Methods : Four hundred and sixty five strains of S. pneumoniae were isolated from various clinical specimens at the Seoul National University Children's Hospital during a 15 year-period, from 1991 to 2005, were subjected to serotype and penicillin susceptibility. The study period was divided into three 5 year-periods, 1991~1995(period I), 1996~2000(period II), and 2001~2005(period III). Results : Common serotypes were 19F, 23F, 19A, 6B, 14, 6A and 9V in decreasing orders of frequency, and these 7 serotypes accounted for 79% of total 465 strains. In the serotype distribution of invasive infection isolates from children <60 months of age, similar serotypes accounted for 70% of 101 strains. In total strains, the proportion of serotype 19A and 6A increased, while that of serotype 19F and 14 decreased. The majority(75~92%) of vaccine types and cross-reactive types from invasive infection isolates was penicillin-resistant, whereas 34.4% of non-vaccine types was penicillin-resistant. Conclusion : Distribution of serotypes of S. pneuomoniae isolated from Korean children has changed significantly over the last 15 years. The surveillance for pneumococcal serotypes should be continued to monitor changes in serotype distribution which are essential for the establishment of pneumococcal vaccine policy.

• Korean Journal of Veterinary Research
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• v.38 no.1
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• pp.85-89
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• 1998

본 연구에서는 돼지 로타바이러스의 혈청형 A, B 및 C를 동시에 진단할 수 있는 RT-PCR 기법을 개발하였다. 각각의 혈청형에 특이적인 primer를 이용하여 RT-PCR 기법으로 분변시료에서 직접 바이러스 동정을 실시한 결과, 23건의 로타바이러스 감염 분변 시료에서 13건이 혈청형 A, 3건이 혈청형 B, 2건이 혈청형 C로 나타나 국내에서도 A, B 및 C형의 돼지 로타바이러스가 공히 발생하고 있음을 확인하였으며, 발생분포는 외국의 예와 유사하였다. 이 RT-PCR기법은 돼지 로타바이러스의 주요 혈청형인 A, B 및 C형의 동시감별진단법으로 이용될 수 있을 것으로 판단된다.

• Pediatric Infection and Vaccine
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• v.22 no.2
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• pp.97-105
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• 2015

Purpose: Serotyping pneumococcal isolates is important to monitor efficacy of pneumococcal vaccines. Because of difficulties of typing pnueumocci, a multiplex bead-based (multibead) serotyping assay was recently introduced. The aim of this study is to establish a new multibead serotyping assay and to apply this method to analyze clinical isolates of pneumococci in Korea. Methods: To establish the multibead serotyping assay, six key reagents were transferred from University of Alabama at Birmingham (UAB) to Ewha Center for Vaccine Evaluation and Study (ECVES): bead set coated with polysaccharide and monoclonal antibody pool were used in one multiplex inhibition-type immunoassay and 2 bead sets coated DNA probe and 2 primer pools were used in two multiplex PCR-based assays. After multibead serotyping assay was set up, 75 test samples of pneumococci were analyzed whether ECVES is able to identify serotype correctly. After confirming the performance, serotyping assay was applied to identify serotypes of 528 clinical isolates of pneumococci collected from 3 different hospitals. Results: After establishment of the multibead pneumococcal serotyping assay system at ECVES, 75 test samples were analyzed. There was no discrepancy of serotypes of 75 test samples between the results assigned at UAB and those at ECVES. The serotypes of 528 pneumococci isolated from patients or healthy subjects were determined in 94.3% of isolates (498/528). Conclusions: The multibead pneumococcal serotyping assay can be successfully established in Korea. With this method, surveillance of serotypes of pneumococci isolated from patients as well as healthy subjects could be studied.

• Clinical and Experimental Pediatrics
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• v.50 no.2
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• pp.151-156
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• 2007

Purpose : Streptococcus pneumoniae is a major etiologic agent for pneumonia, meningitis, otitis media, and sepsis among young children. Multi-drug resistant strains have raised great concern worldwide, thus the importance of prevention with vaccines has been emphasized. However, vaccines may force the appearance of pneumococcal infections by nonvaccine serotypes. Thus, distribution of pneumococcal serotypes should be monitored to estimate vaccine efficacy. We used a new and efficient multibead assay in determining pnemococcal serotypes. Methods : From January to February 2005, 643 children were recruited from ten day care centers to isolate pneumococci from their oropharynx. Pneumococcal serotyping was performed on 62 pneumococcal isolates from 60 children by multibead assay. This immunoassay required two sets of latex particles coated with pneumococcal polysaccharides and serotype-specific antibodies. Twenty four newly developed monoclonal antibodies specific for common serotypes and a pool of polyclonal rabbit sera for some of the less common serotypes were used. Results : The most prevalent pneumococcal serotypes were serotype 6A, 19A, 19F, 23F, and 11A/D/F which accounted more than 50 precent of all the 62 pneumococcal isolates. We found that multibead assay can be performed very rapidly and objectively. Conclusion : This multibead immunoassay was very useful in serotyping clinical isolates of S. pneumoniae because it was simple, reliable and fast.

• Korean Journal of Veterinary Research
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• v.29 no.4
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• pp.475-478
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• 1989

돼지로 부터 분리한 Staphylococcus hyicus subsp hyicus 489주의 혈청형을 자가생산한 인자혈청을 이용한 평판응집반응으로 동정하였다. 분리균의 혈청형은 A(16.8%), C(20.4%), D(9.4%), E(7.2%), F 형(29.2%) 및 미분류형(17.0%)으로 동정되었으며, 돼지의 건강상태, 신체부위 및 연령에 관계없이 F형의 분포가 가장 높았다.

• Korean Journal of Microbiology
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• v.43 no.4
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• pp.346-350
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• 2007

We analyzed the phenotypic changes in coagulase serotype of S. aureus isolated from clinical sources and nasal cavities of healthy persons, $1994{\sim}2005$. A total of 715 isolates, 408 methicillin resistant S. aureus (MRSA) from clinical sources and 307 methicillin-susceptible S. aureus (MSSA), were classified into eight coagulase sero-types, I to VIII. The most prevalent serotype in MRSA was type II (54.3%, 222/408) and followed IV (24.7%), III (10.9%), and V (5.2%), whereas the majorities in MSSA were type VII (30.9%, 95/307), IV (22.2%), V (22.2%) and II (7.1%). Among the isolates collected periods, significant changes of coagulase serotypes in both strains were observed. In MRSA strains, the serotype V was not detected until 1997, but rapidly increased to 18.5% (20/108) in 2005, and the serotypes III decreased from 27% (31/115) in 1994 to 0.9% (1/108) in 2005. A similar trend in MSSA strains was observed but serotype II strain was not detected in 2005. The antigenic shift and changes in the coagulase of S. aureus were confirmed.

• Korean Journal of Veterinary Research
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• v.27 no.2
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• pp.223-226
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• 1987

Serological classification was carried out on 10 samples of PEV isolated from the feces, the milk and the brain of the diseased pigs in Korea by CFT using type specific antisera of PEV. Ten samples of PEV were classified into 2 serotypes which were serotype 3 and 8. PEV from the feces belonged to serotype 8 and those from the milk and the brain to serotype 3. The cross reaction of serotype 3 occurred especially with serotype 1. Talfan virus. It can be said that at least 2 serotypes of PEV have existed in Korea.

• Pediatric Infection and Vaccine
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• v.7 no.1
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• pp.94-107
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• 2000

Purpose : The purpose of this study is to know the clinical manifestations and the severity of adenoviral lower respiratory tract infections(LRTI) in Korean children. Methods : Adenoviral respiratory infection was diagnosed by viral culture in HEp-2 cell and indirect immunofluorescent technique with nasal aspirates. Isolated adenoviruses were typed by neutralization test. Retrospective chart review was done in patients with adenoviruses were typed by neutralization test. Retrospective chart review was done in patients with adenoviral lower respiratory tract infection, who were brought to Seoul National University Children's Hospital from November 1990 through February 1998. Results : Adenovirus was isolated in 87 cases. Of 84 cases serotyped, type 1 was recovered in 3 cases, type 2 in 13 cases, type 3 in 13, type 4 and 5 in 4 cases each other, type 6 in 1 cases, type 7 in 36 cases, type 11 in 1 case and the other types in 9 cases. Adenoviral lower respiratory infection occurred sporadically throughout the year but from November 1995 through February 1998, an outbreak of adenovirus type 7 lower respiratory infection was observed in number upto 36 case. The incidence of adenoviral infection peaked in young children between 6 months and 5 years of age and the mean age was 1 year 11 months old. There were 10 cases of mixed infection with another pathogen. Clinical diagnosis were pneumonia(88%), acute broncholitis(5.4%), acute tracheobronchitis(5.4%), croup(1.3%). The clinical features of adenoviral lower respiratory infection were severe especially in type 3 and 7 infections in aspect of fever duration, ventilator care. Extrapulmonary manifestations were gastrointestinal symptoms in 23 cases(31%), hepatomegaly in 36 cases(53%), seizure and mental alteration in 13 cases(20.3%). In chest radiographic findings, parahilar and peribronchial infiltration were in 49 cases(67%), hyperaeration in 21 cases(29%), atelectasis in 14 cases(19%), consolidation in 39 cases(53%) and bilateral pneumonic infiltration in 28 cases(38%). Among thirty six adenovirus type 7 LRTI, 15 patients(41.6%) had pleural effusion and 3 patients had chest tube insertion. Number of fetal cases related to adenovirus were 9 cases(12%) and fetal cases due to ventilatory failure were 7(11%). Conclusion : During 7 year period of studying adenoviral lower respiratory infection, we identified the serotypes of adenovirus. Among the serotypes, adenovirus type 7 were epidemically isolated. Adenovirus were isolated in severe lower respiratory infection of young children aged between 6 months and 5 years and related to death of the patients, especially when the patients had underlyng diseases or were infected by adenovirus type 7.

• Clinical and Experimental Pediatrics
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• v.48 no.5
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• pp.506-511
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• 2005

Purpose : Streptococcus pneumoniae serotype 6B and 6A are important pathogens in pneumococcal infections. It is commonly assumed that the 6B vaccines elicit antibodies cross-reacting with the 6A serotype and the cross-reactive antibodies protect against infections of 6A. To examine this assumption, we measured the opsonophagocytic capacity to serotype 6A and 6B in adults. Methods : Twenty-four adults were immunized with pneumococcal PS vaccine that contains 6B PS. Their preimmune and postimmune sera were studied for the capacity to opsonize 6B and 6A serotypes with opsonophagocytic killing assay. Results : Opsonization titers to 6B were significantly higher than those to 6A in preimmune and postimmune sera. Because significant increasesof opsonization titers were observed in adults with polysaccharide vaccines for 6A(cross-reactive) serotype as well as for 6B(vaccine) serotype, 6B PS in vaccine elicited cross-protective antibodies to 6A, but not in all cases. One adult did not have detectable levels of opsonization titers to 6A after immunization. Conclusion : Although 6B PS in pneumococcal PS vaccine elicits antibodies cross-reacting with 6A serotype in some adults, it may not occur always. This study should be extended to other age groups such as children and elderly people. The presence of the cross-protection should be directly determined in clinical trials of the pneumococcal vaccines as well as during the postlicensure monitoring surveys by serotyping the clinical isolates of pneumococci.