Osong Public Health and Research Perspectives

Seung-Hak Cho

9 Articles

Corrigendum to “Epidemiological Characterization of Imported Systemic Mycoses Occurred in Korea” [Osong Public Health Res Perspect 2018;9(5):255–60]: Seung-Hak Cho, Young-Bin Yu, Je-Seop Park, Keun-Dol Yook, Young-Kwon Kim; Osong Public Health Res Perspect. 2018;9(6):362-362. Published online December 31, 2018; DOI: https://doi.org/10.24171/j.phrp.2018.9.6.11

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Epidemiological Characterization of Imported Systemic Mycoses Occurred in Korea: Seung-Hak Cho, Young-Bin Yu, Je-Seop Park, Keun-Dol Yook, Young-Kwon Kim; Osong Public Health Res Perspect. 2018;9(5):255-260. Published online October 31, 2018; DOI: https://doi.org/10.24171/j.phrp.2018.9.5.07

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Abstract PDF: Objectives
Imported systemic mycoses is a severe fungal infection that can cause diseases in healthy people. However, there is a serious lack of epidemiological data about imported systemic mycoses. Therefore, an epidemiological characterization of imported systemic mycoses in Korea was performed.
Methods
We collected health insurance data between 2008 and 2012 from the Health Insurance Corporation and analyzed the data to determine the prevalence and treatment management of imported systemic mycoses.
Results
The prevalence of imported systemic mycoses between 2008 and 2012 increased slowly by 0.49/100,000 to 0.53/100,000 persons. The prevalence of coccidioidomycosis increased from 0.28/100,000 in 2008 to 0.36/100,000 persons in 2012. A mean of 229.6 cases occurred each year. Children and the elderly showed higher prevalence than adults in the 20- to 59-year-old age group. The rate of infection according to region ranged from 0.18/100,000 persons in Ulsan, to 0.59/100,000 persons in Gyeonggi. The prevalence in females was higher than that in males. Inpatient treatment was 3.3% (38 cases), with 96.7% treated as outpatients. Hospitalizations cost 272.7 million won and outpatient treatments cost 111.7 million won. The treatment cost for coccidioidomycosis from 2008 to 2012 was 330.9 million won, with personal charges of 79.2 million won and insurance charges of 251.7 million won. Most of the expenses for the coccidioidomycosis treatment were for inpatient treatment.
Conclusion
The results in this study may be a useful resource for determining the changes in the trend of imported systemic mycoses.

Characterization of Clostridium difficile Strains Isolated from Patients with C. difficile-associated Disease in Korea: Seung-Hak Cho, Jung-Whan Chon, Kun-Ho Seo, Young Kwon Kim, Jung-Beom Kim, Young-Seok Bak, Woon-Won Jung, Cheorl-Ho Kim, Jong Tae Choi; Osong Public Health Res Perspect. 2017;8(5):325-331. Published online October 31, 2017; DOI: https://doi.org/10.24171/j.phrp.2017.8.5.06

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Abstract PDF: Objectives
Studies on Clostridium difficile are rare in Korea. We investigated the epidemiological characteristics of C. difficile isolates from patients with C. difficile-associated disease (CDAD) in Korea.
Methods
Multiplex polymerase chain reaction was performed to detect the presence of tcdA and tcdB toxin genes. Antimicrobial susceptibility test was carried out by the disk-dilution method. C. difficile strains were subtyped by automated repetitive-element palindromic PCR (rep-PCR).
Results
Among patients with CDAD, 73 (25.8%), 32 (11.3%), 32 (11.3%), and 26 (9.2%) suffered from pneumonia, cancer or neoplasm, diabetes, and colitis, respectively. Of all stool samples, 43 samples (15.2%) were positive for C. difficile strains. We observed two expression patterns of toxin genes: tcdA+/tcdB+ (86% isolates) and tcdA−/tcdB+ (14% isolates), with all isolates expressing tcdB. Furthermore, some isolates were resistant to clindamycin (65%), ampicillin (56%), and cefazolin (40%), but all were susceptible to vancomycin and metronidazole. The tested samples were classified into diverse clusters using automated rep-PCR.
Conclusion
Our findings revealed the characteristics and antibiotic resistance of C. difficile isolates from patients in Korea. The epidemiological data may provide valuable insight into development of treatment strategies for C. difficile infections in Korea.

Epidemiological Characterization of Skin Fungal Infections Between the Years 2006 and 2010 in Korea: Sang-Ha Kim, Seung-Hak Cho, Seung-Ki Youn, Je-Seop Park, Jong Tae Choi, Young-Seok Bak, Young-Bin Yu, Young Kwon Kim; Osong Public Health Res Perspect. 2015;6(6):341-345. Published online December 31, 2015; DOI: https://doi.org/10.1016/j.phrp.2015.10.012

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Abstract PDF: Objectives
The purpose of this study was to build and provide a basic database of skin fungal infections for the effective management of skin fungal infections in the future.
Methods
We collected health insurance data between the years 2006 and 2010 from the Health Insurance Corporation (Seoul, Korea) and analyzed the data to determine the prevalence and treatment management of skin fungal infections.
Results
Skin fungal infections were divided into two groups: namely dermatophytosis and other superficial mycoses. Dermatophytosis showed a higher prevalence (16,035,399 cases) than the other superficial mycoses (794,847 cases) within the study period. The prevalence rate decreased consecutively by 0.01% to 0.19% every year. The prevalence according to region showed that Jeolla-do had a high prevalence distribution. The prevalences in men and women were similar (7.01% vs. 6.26%). It is interesting to note that adults from the 50–79-year age group showed a higher prevalence than children and young adults. The average convalescence time (days) of dermatophytosis was longer than that of other superficial mycoses. The total medical expenses were also much higher in dermatophytosis than in the other superficial mycoses.
Conclusion
This study provides useful data for study trends of skin fungal infections.

Possibility of CTX-M-14 Gene Transfer from Shigella sonnei to a Commensal Escherichia coli Strain of the Gastroenteritis Microbiome: Seung-Hak Cho, Soon Young Han, Yeon-Ho Kang; Osong Public Health Res Perspect. 2014;5(3):156-160. Published online June 30, 2014; DOI: https://doi.org/10.1016/j.phrp.2014.04.007

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Abstract PDF: Objectives
To investigated whether the CTX-M-14 gene could be transferred from a clinical Shigella sonnei strain to commensal Escherichia coli strain in the gastroenteritis microbiome.
Methods
E. coli strains were isolated from 30 stool samples of S. sonnei infected students in a gastroenteritis outbreak in 2004 and were characterized by antibiotic resistance analysis, in vitro conjugation and in vivo transfer of CTX-M-14 gene and molecular assays.
Results
One strain of Escherichia coli that had high levels of resistance to cefotaxime was isolated from a patient infected with S. sonnei. Isoelectric focusing showed that the E. coli and S. sonnei strains produced a β-lactamase with an isoelectric point of 8.1. Moreover, polymerase chain reaction analysis indicated that both strains possessed the same DNA sequences for CTX-M-14. The results of in vitro and in vivo conjugation showed that the efficiency of CTX-M-14 transfer from S. sonnei to E. coli was similar to CTX-M-14 transfer between E. coli strains.
Conclusion
The data suggest that the acquisition of the extended-spectrum β-lactamases gene by pathogenic bacteria in the human intestinal tract to commensal microbiome bacteria can cause serious infectious diseases.

Prevalence of Antimicrobial Resistance in Escherichia coli Strains Isolated from Fishery Workers: Hyun-Ho Shin, Seung-Hak Cho; Osong Public Health Res Perspect. 2013;4(2):72-75. Published online April 30, 2013; DOI: https://doi.org/10.1016/j.phrp.2013.03.001

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Abstract PDF: Objectives
This study aimed to characterize the prevalence of antibiotic resistance in Escherichia coli isolates from the fecal samples of fishery workers who work in fish farms and often use antibiotics for the feeding fishes.
Methods
Seventy-three E. coli strains isolated from the fecal samples of fishery workers and 180 isolates from a control group of restaurant workers were tested for antibiotic resistance by agar disk diffusion with 16 antimicrobial agents.
Results
About 30% of isolates from each group showed antimicrobial resistance to ampicillin, and 60% of isolates from fishery workers and 41% from restaurant workers were resistant to tetracycline. The isolates showed higher resistance to cephalothin and cefoxitin than to other cephem antibiotics and to gentamicin than to other aminogycosides. Our data indicated that fecal E. coli isolates from fishery workers showed higher antibiotic resistance than those of non-fishery workers (restaurant workers), especially to cephalothin, tetracycline, and trimethoprim–sulfamethoxazole (p < 0.05). However, rates of multidrug resistance were similar among the fishery workers and restaurant workers.
Conclusion
Frequent use of antibiotics may cause increased antibiotic resistance in the human microbiome.

Comparison of Antimicrobial Resistance in Escherichia coli Strains Isolated From Healthy Poultry and Swine Farm Workers Using Antibiotics in Korea: Seung-Hak Cho, Yeong-Sik Lim, Yeon-Ho Kang; Osong Public Health Res Perspect. 2012;3(3):151-155. Published online June 30, 2012; DOI: https://doi.org/10.1016/j.phrp.2012.07.002

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Abstract PDF: Objectives
The aim of this study is to compare the antibiotic resistance of Escherichia coli isolates from faecal samples of workers who often use antibiotics.
Methods
A total of 163E coli strains isolated from faecal samples of livestock workers (poultry and swine farm workers) and restaurant workers in the same regions as a control group were analyzed by agar disc diffusion to determine their susceptibility patterns to 16 antimicrobial agents.
Results
Most of the tested isolates showed high antimicrobial resistance to ampicillin and tetracycline. The isolates showed higher resistance to cephalothin than other antibiotics among the cephems. Among the aminoglycosides, the resistance to gentamicin and tobramycin occurred at higher frequencies compared with resistance to amikacin and netilmicin. Our data indicated that faecal E coli isolates of livestock workers showed higher antibiotic resistances than nonlivestock workers (restaurant workers), especially cephalothin, gentamicin, and tobramycin (p < 0.05). Moreover, the rates of the livestock workers in the association of multidrug resistance were also higher than the rates of the restaurant workers.
Conclusion
This study implies that usage of antibiotics may contribute to the prevalence of antibiotic resistance in commensal E coli strains of humans.

Prevalence of Antibiotic Resistance in Escherichia coli Fecal Isolates From Healthy Persons and Patients With Diarrhea: Seung-Hak Cho, Yeong-Sik Lim, Mi-Sun Park, Seong-Han Kim, Yeon-Ho Kang; Osong Public Health Res Perspect. 2011;2(1):41-45. Published online June 30, 2011; DOI: https://doi.org/10.1016/j.phrp.2011.05.003

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Abstract PDF: Objectives
This study aimed to investigate the prevalence of antibiotic resistance in fecal Escherichia coli isolates from healthy persons and patients with diarrhea.
Methods
E. coli isolates (n = 428) were obtained from fecal samples of apparently healthy volunteers and hospitalized patients with diarrhea. Susceptibility patterns of isolates to 16 antimicrobial agents were determined by agar disc diffusion.
Results
Most E. coli isolates exhibited less than 10% resistance against imipenem, cefotetan, aztreonam, cefepime, cefoxitin, amikacin and netilamicin, although greater than 65% were resistant to ampicillin and tetracycline. No significant difference in resistance rates for all tested antibiotics was found between isolates from the healthy-and diarrheal-patient groups, including for multi-drug resistance (p = 0.22). The highest number of resistant antibiotics was 12 antibiotics. No significant differences in antibiotic resistance were found among the sex and age strata for isolates from healthy individuals. However, antibiotic resistance rates to cefoxitin, cefotaxime, amikacin, and netilamicin were significantly higher in the isolates of men than those of women (p < 0.05) in isolates from patients with diarrhea. Furthermore, isolates from patients with diarrhea older than 40-years of age showed higher resistance to cefepime and aztreonam (p < 0.05).
Conclusion
High resistance to the antibiotics most frequently prescribed for diarrhea was found in isolates from patients with diarrhea and apparently healthy individuals without any significant difference.

Distribution of Virulence Genes and Their Association of Serotypes in Pathogenic Escherichia coli Isolates From Diarrheal Patients in Korea: Seung-Hak Cho, Kyung-Hwan Oh, Seong-Han Kim, Hee-Bok Oh, Mi-Sun Park; Osong Public Health Res Perspect. 2010;1(1):29-35. Published online December 31, 2010; DOI: https://doi.org/10.1016/j.phrp.2010.12.008

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Abstract PDF: Objectives
To characterise the genetic and serological diversity of pathogenic Escherichia coli, we tested 111 E coli strains isolated from diarrhoeal patients in Korea between 2003 and 2006.
Methods
The isolates were tested through polymerase chain reaction (PCR) and slide agglutination method for the detection of virulence genes and serotypes, respectively. To compare the expression of Shiga toxin (stx)-1 and stx2 genes, real-time quantitative reverse-transcriptase PCR and rapid exprssion assay, reversed-passive latex agglutination, were performed.
Results
Forty-nine Shiga toxin-producing E coli (STEC) strains and 62 non-STEC strains, including 20 enteropathogenic E coli, 20 enterotoxigenic E coli, 20 enteroaggregative E coli, and 2 enteroinvasive E coli were randomly chosen from the strains isolated from diarrhoeal patients in Korea between 2003 and 2006. PCR analysis indicated that locus of enterocyte effacement pathogenicity island, that is, eaeA, espADB, and tir genes were present in STEC, enteropathogenic E coli, and enteroinvasive E coli. Quorum sensing-related gene luxS was detected in most of pathogenic E coli strains. Major serotypes of the STEC strains were O157 (26%) and O26 (20%), whereas the non-STEC strains possessed various serotypes. Especially, all the strains with serotype O157 carried stx2 and the tested virulence factors. Of the STEC strains, the data of real-time quantitative reverse-transcriptase PCR and reversed-passive latex agglutination tests showed that messenger RNA- and protein expression of stx2 gene were higher than those of stx1 gene.
Conclusion
Our results provide the epidemiological information regarding the trend of STEC and non-STEC infections in the general population and show the fundamental data in association of serotypes with virulence genes in diarrhoeagenic E coli strains from Korea.

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