• Journal of Microbiology
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• v.41 no.1
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• pp.1-6
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• 2003

The genetic relatedness of multidrug-resistant pneumococcal isolates of serotypes 19F and 23F was investigated. The DNA fragments digested with Sma I were resolved by pulsed-field gel electrophoresis (PFGE). PFGE analysis of 365. pneumoniae isolates showed 13 different patterns. Among 22 isolates of serotype 19F, 9 different PFGE patterns were present and 14 isolates of serotype 23F isolates represented 5 distinct PFGE patterns. Two isolates of serotype 19F and six isolates of serotype 23F shared the same PFGE pattern (Pattern I). Based on the genetic relatedness within the strains (one genetic cluster was defined as having more than 85% homology), we divided the pneumococcal strains into genefic clusters (Ⅰ, II, III, IV, V, and VI). The 22 strains of serotype 19F belonged to five distinct genetic clusters (I, II, III, IV, V and VI) and 14 strains of serotype 23F represented two genetic clusters (I and II ). These results showed that strains of serotype 19F are genetically more diverse than those of serotype 23F, Serotype 19F isolates with PFGE patterns H and I appeared to be less related to those of the remaining PFCE patterns (A to G) (less than 60% genetic relatedness), but those strains were genetically closely related with serotype 23f. These results suggest that the latter isolates originated from horizontal transfer of the capsular type 19F gene locus to 23F pneumococcal genotypes. In conclusion, the multidrug-resistant pneumococcal isolates of serotype 19f and 23F isolated in Korea are the result of the spread of a limited number of resistant clones.

• Korean Journal of Veterinary Research
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• v.42 no.4
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• pp.495-504
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• 2002

Streptococcus suis is an important swine pathogen in nearly all countries with an extensive pig industry. It is associated with meningitis, arthritis, endocarditis, septicaemia, bronchopneumonia and sudden death. Attempts to control the disease are still hampered the lack of effective vaccines and sensitive diagnostic tools. A PCR method which can be used for the detection of virulent strains of serotype 2, which is most prevalent serotype, and serotype 1 was developed. However, serotype 1, 2, 7 and 9 strains are frequently isolated from diseased pigs. In European countries, S suis serotype 2 is the most prevalent type isolated from diseased pigs, followed by serotype 9 and 1. In Japan, capsular serotype 2 was also the most prevalent serotype, followed by capsular serotype 7. Most of S suis isolated from diseased pigs belong to a limited number of capsular serotype, often those between 1 and 9. We investigated the distribution of S suis serotype 1, 2, 7 and 9 from 740 pig lungs at abattoir in Jeolla and Chungcheong by rapid multiplex PCR assay. Fifty of 740 lung samples, 6.8%, were S suis postitive and identified S suis were divided by 38% (19/50) in serotype 2, 2% (1/50) in serotype 7 and 4% (2/50) in serotype 9. The distribution of S suis serotype in Korea was similar to other countries. Moreover, the multiplex PCR assay may be an useful diagnostic tool for the detection of pigs carrying serotype 1, 2, 7, 1/2, 9 and 14 strains in epidemiological and transmission studies and facilitate control and eradication programs.

• Korean Journal of Microbiology
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• v.27 no.3
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• pp.231-236
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• 1989

The larger segment of double stranded RNA genome from a new serotype of Infectious Pancreatic Necrosis Virus (IPNV), DRT, has been partially cloned at Sma I site in pUC19 and compared with the restriction maps of VR-299 and Sp. Restrction sites found in DRT was distinct and hence a new serotype. The cDNA clones of DRT were about 800, 850, and 1, 400 bp long each and do not share any common restiction site. It is not clear yet if there exist any overlapping sequences among them. This partial cloning, however, was sufficient for the comparison of restriction maps with the other serotypes.

• Clinical and Experimental Pediatrics
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• v.52 no.4
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• pp.508-511
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• 2009

Streptococcus pneumoniae is a major cause of serious invasive diseases in children, especially in young infants, but seven- valent pneumococcal conjugate vaccine (PCV7) is believed to prevent invasive pneumococcal pneumonia and meningitis in young children. However, recently, the incidence of non-PCV7 serotype has increased after PCV7 vaccination. A 14-month- old female patient presented at our emergency room with mental change and lethargy. Three days previously, she had developed fever and vomiting. After being admitted, she rapidly progressed to coma and brain death despite prompt and extensive supportive treatment. She expired 20 days after admission with a final diagnosis of pneumococcal 19A (non-PCV7 serotype) meningoencephalitis despite having received PCV7 ($Prevenar^{(R)}$) vaccinations on three occasions. The author reports this first fatality due to pneumococcal 19A meningoencephalitis in Korea and provides a brief review of the literature.

• 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.

• Clinical and Experimental Pediatrics
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• v.54 no.4
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• pp.163-168
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• 2011

Purpose: The purpose of this study was to evaluate the immune response to serotype 19A in children aged 12-23 months after immunization of the 19F containing 7-valent pneumococcal conjugate vaccine (PCV7). Methods: Blood samples from a total of 45 subjects (age 12-23 months) were included in the study. Subjects were categorized according to immunization status into three groups as follows: 18 subjects with 3 primary doses and 1 booster dose of PCV7 (booster group), 21 subjects with 3 primary doses before 12 months of age (primary group), and 6 subjects with no vaccination history of PCV7 (control group). An ELISA and opsonophagocytic killing assay (OPKA) was done to evaluate the immune responses against serotypes 19F and 19A. Results: According to the ELISA, all subjects had antibody titers ${\geq}0.35{\mu}g/mL$ for serotypes 19F and 19A in the booster and primary group and 83.0% and 66.7% in the control group, respectively. According to the OPKA, subjects with opsonic activity (${\geq}20$) against serotypes 19F and 19A were 100% and 61.1% of the subjects in the booster group and 66.7% and 19.0% in the primary group, respectively. No subjects in the control group had opsonic antibodies against both serotypes. Conclusion: In conclusion, in children 12-23 months age who were previously vaccinated with PCV7, a cross-reactive immune response is elicited against serotype 19A after a primary series of 3 doses in a small proportion of subjects, and this response is amplified after booster vaccination.

• Pediatric Infection and Vaccine
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• v.15 no.1
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• pp.45-51
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• 2008

Purpose : Better understanding of the epidemiology of Streptococcus pneumoniae affects preventive and therapeutic strategies for children with otitis media. This study was undertaken to examine the prevalence of pneumococcal serotypes causing otitis media in children. Methods : Pneumococcal isolates obtained from the ear discharge of children with otitis media between January 2001 and December 2006 were characterized by serotyping and antibiotic susceptibility testing. Results : There were 54 pneumococcal isolates from 54 children with otitis media. The median age of patients was 13 months, and the proportion of children <5 years old was 81%. The predominant serotypes, in order of decreasing frequency, were 19A (44%), 19F(28%), 6B (7%), 6A (4%), 9V (4%), and 1 (4%); 23 isolates (43%) belonged to types included in the heptavalent pneumococcal conjugate vaccine (PCV7). The proportion of serotype 19A and 19F accounted for 72% of overall pneumococcal isolates, which accounted for 84% of pneumococcal isolates from otorrhea of children <5 years old (vs 20% in children ${\geq}5$ years old, P<0.001). All serotypes isolated from 3 vaccinees of PCV7 were 19A. There was no significant diminution in otitis media caused by pneumococcal vaccine serotypes after the introduction of PCV7. The frequency of nonsusceptibility to penicillin, erythromycin, and trimethoprim-sulfamethoxazole was higher in serotype 19A than in other non-vaccine serotypes, respectively. The frequency of multiple drug resistance was 96% in serotype 19A, compared with 29% in other non-vaccine serotypes (P=0.001). Conclusion : 19A was the most common pneumococcal serotype causing otitis media and represented a large proportion of strains with multiple drug resistance in children younger than 5 years of age.

• Journal of fish pathology
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• v.33 no.2
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• pp.119-125
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• 2020

During the period from 2003 to 2020, a total of 470 Streptococcus species were isolated from farmed flounder in Jeju. Out of 470 isolates, 92 (19.6%) isolates and 378 isolates (80.4%) were identified as Streptococcus iniae and S. parauberis, respectively by multiplex PCR assay. During that period, the percentage of S. iniae decreased from 56.9% in 2003 to 0.0% in 2020 whereas that of S. parauberis increased from 43.1% in 2003 to 100% in 2020. In the PCR assay for serotyping, the isolated S. parauberis showed 3 subserotypes, Ia (34.9%), Ib/Ic (46.3%) and II (18.8%). In 2003 and 2004, serotype II was dominant at 59.1% and 50.0% of isolation rates, however between 2005 and 2009, subserotype Ib/Ic was dominant (57.6%, 86.0%, 84.6%, 57.9%, and 83.3%). After 2010, except for 2015, subserotype Ia was the most dominant one. In the last 3 years (2018 to 2020), subserotype Ia was most abundant (70%), followed by subserotype Ib/Ic (16-30%). Serotype II was not isolated in 2018, but in 2019 and 2020, it showed an increased tendency to 3.4% and 16.7%, respectively. It is believed that continuous monitoring is necessary for research on counter-measures against streptococcosis of flounder.

• Korean Journal of Veterinary Research
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• v.34 no.1
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• pp.85-91
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• 1994

A study on the isolation of Yersiniae from the feces of wild animals(mammals 376, birds 19 and reptiles 13) in zoo and the biotype and serotype and susceptibility of 12 antibiotics was carried. Out of 408 animals, Yersiniae were isolated from 28 animals(6.9%). Of 28 isolates, 27 isolates(96.4%) were Y. enterocolitica and 1(3.6%) was Y. kristensenii. According to the species, 25(6.6%) of Y. enterocolitica and 1(0.3%) of Y. kristensenii were isolated from 376 mammals, 2(15.4%) of Y. enterocolitica from 13 reptiles but not isolated from 19 birds. According to the eating pattern, 8(5.2%) of Y. enterocolitica were isolated from 155 carnivora, 13(10%) of Y. enterocolitica from 123 herbivora, and 6(4.9%) of Y. enterocolitica and 1(0.8%) of Y. enterocolitica from 123 omnivora. Out of 27 isolates of Y. enterocolitica, all were biotype 1. And predominant serotype was 0:21(40.7%), and 0:5(37.0%), 0:6(11.1%), 0:1(3.7%), 0:9(3.7%) and untypable(3.7%). Yersiniae isolated from zoo animals were resistant to cephalothin(100%), ampicillin(96.4%), carbenicillin(96.4%) and tetracycline(14.3%) and streptomycin(3.6%) and susceptible to chloramphenicol(100%), colistin(100%), gentamicin(100%), kanamycin(100%), nalidixic acid(100%), polymyxin B(100%) and tobramycin(100%). The predominant multiple resistance pattern was Am-Cf-Cb(82.1%), and Am-Cf-Cb-Te(10.7%) and Am-Cf-Cb-Te-Sm(3.7%).

• Korean Journal of Microbiology
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• v.42 no.4
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• pp.257-264
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• 2006

Fifty eight Cryptococcus neoformans strains isolated from clinical and environmental sources in Korea were examined for their serotypes and extracellular enzyme activities. Among the 51 strains isolated from clinical sources, 48 strains were serotype A (94.1%), 2 strains were serotype B (3.92%), and 1 strain was serotype D (1.96%). All seven environmental strains isolated from pigeon excreta were identified as serotype A. All isolates of C. neoformtans were positive for the production of extracellular proteinase and phospholipase. In the API-ZYM system, all fifty eight isolates produced alkaine phosphatase, esterase C4, esterase lipase: C8, leucine arylamidase, acid phosphatase, naphthol-AS-BI-phosphohydrase, $\alpha$-glucosidase and $\beta$-glucosidase. Thirty nine isolates (67.2%) of C. neoformans produced N-acetyl-$\beta$-glucosidase. Two isolates, serotype B, and B only one serotype A produced $\beta$-glucuronidase. Analysis of enzymatic profiles to 21 enzymes revealed four biotypic patterns among the 58 strains. The enzymatic patterns of C. neoformans isolated from clinical and environmental sources represented a significant relationship with the serotypes.