• Journal of Life Science
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• v.20 no.10
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• pp.1544-1548
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• 2010

Moxifloxacin (MF) - resistant mutants of Mycoplasma hominis (M. hominis) were generated by stepwise selection in increasing concentrations of MF, and six strains of MF resistant M. hominis mutants - M1, M4, M8, M16, M32, and M64 - in which MICs of MF were 0.5, 4, 8, 16, 32, 64 ${\mu}g$/ml, respectively, were generated. Compared to the sequence of M. hominis PG21, all mutants harbored amino acid substitutions of Arg-163 Thr in GyrA, and Pro-445 Gln in ParE. While the concentrations were getting higher, an additional amino acid substitution was found at Ser-153 Lys in GyrA (${\geq}4{\mu}g/ml$), Ser-91 Ile in ParC (${\geq}16{\mu}g/ml$), and Val-450 Phe (${\geq}64{\mu}g/ml$) in GyrB. These substitutions seem to have an impact on resistance to MF, and GyrB change was found only in the highest concentration and seems to be associated with high-level resistance to MF. This, as far as we know, is the first description of a relationship between MF resistance phenotype and genotype.

• Microbiology and Biotechnology Letters
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• v.46 no.1
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• pp.85-90
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• 2018

Sexually transmitted infections (STIs) are a global health concern and can cause serious complications such as miscarriage, premature birth, and pelvic infection in pregnant women. Therefore, accurate diagnosis and information on the epidemiologic trends are critical. However, studies of STI trends in Cheonan, South Korea, have not been conducted since 2012. We examined the STI trends in the Cheonan area after 2012. From January 2011 to September 2017, 3,362 cervical swab specimens from female patients were sampled at the Dankook University Hospital and analyzed by multiplex PCR. Of the 3,362 specimens, 1,281 were positive for pathogens (38.92%). A total of 1,893 pathogens were detected. Ureaplasma urealyticum, Mycoplasma hominis, and Chlamydia trachomatis were the most frequent pathogens, accounting for 36.29% (687/1,893), 30.16% (571/1,893), and 19.97% (378/1,893) of the pathogen-positive samples, respectively. In the 2009-2012 analysis, M. hominis was identified as the predominant pathogen in STI samples, whereas U. urealyticum was identified as the major pathogen in this study. In many countries, including South Korea and the United States, the rate of STIs is increasing, while a decreasing trend was observed in Cheonan.

• Clinical and Experimental Reproductive Medicine
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• v.44 no.4
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• pp.207-213
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• 2017

Objective: This study investigated the prevalence of infections with human papillomavirus, Chlamydia trachomatis, Ureaplasma urealyticum, Mycoplasma hominis, and Mycoplasma genitalium in the semen of Korean infertile couples and their associations with sperm quality. Methods: Semen specimens were collected from 400 men who underwent a fertility evaluation. Infection with above five pathogens was assessed in each specimen. Sperm quality was compared in the pathogen-infected group and the non-infected group. Results: The infection rates of human papillomavirus, C. trachomatis, U. urealyticum, M. hominis, and M. genitalium in the study subjects were 1.57%, 0.79%, 16.80%, 4.46%, and 1.31%, respectively. The rate of morphological normality in the U. urealyticum-infected group was significantly lower than in those not infected with U. urealyticum. In a subgroup analysis of normozoospermic samples, the semen volume and the total sperm count in the pathogen-infected group were significantly lower than in the non-infected group. Conclusion: Our results suggest that infection with U. urealyticum alone and any of the five sexually transmitted infections are likely to affect sperm morphology and semen volume, respectively.

• The Journal of the Korean Society for Microbiology
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• v.34 no.6
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• pp.573-582
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• 1999

Cytokines are hormone-like proteins which mediate and regulate inflammatory and immune responses. The purpose of this study was to investigate the effect of lipopolysaccharide (LPS), Staphylococcus enterotoxin B (SEB), and Mycoplasma lysates on regulation of IL-6 and IL-8 production by human nasal fibroblasts. Primary cultured cells were incubated with LPS ($1.0\;{\mu}g/ml$) from E.coli, SEB ($1.0\;{\mu}g/ml$) from S.aureus, or Mycoplasma lysates (M.pneumoniae, Mp; M. fermentans, Mf; M. hominis, Mh, each $1.0\;{\mu}g/ml$). The culture supernatants were collected at 2, 6, and 24 hr and assessed for IL-6 and IL-8 production by enzyme-linked immunosorbent assay. The production of IL-6 in the culture supernatant was downregulated by LPS, SEB, or Mycoplasma lysates. But IL-6 was upregulated by mixed exposure with Mp+LPS (2 hr), Mp+LPS+SEB (24 hr), Mf+LPS (24 hr), Mf+LPS+SEB (2 hr), Mh+LPS (24 hr), Mh+SEB (24 hr), or Mh+LPS+SEB (24 hr). The production of IL-8 in the culture supernatant was similar to that of IL-6 by same stimulants. But IL-8 was upregulated by mixed exposure with Mf+LPS+SEB (2 hr), Mh+LPS (24 hr), Mh+ SEB (24 hr), or Mh+LPS+SEB (24 hr). These studies show that costimulation of LPS or SEB with Mycoplasma whole cell lysates upregulates the production of IL-6 and IL-8.

• Journal of Microbiology
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• v.44 no.1
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• pp.42-49
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• 2006

In this study, we describe our newly-developed sensitive two-stage PCR procedure for the detection of 13 common mycoplasmal contaminants (M. arthritidis, M. bovis, M. fermentans, M. genitalium, M. hominis, M. hyorhinis, M. neurolyticum, M. orale, M. pirum, M. pneumoniae, M. pulmonis, M. salivarium, U. urealyticum). For primary amplification, the DNA regions encompassing the 16S and 23S rRNA genes of 13 species were targeted using general mycoplasma primers. The primary PCR products were then subjected to secondary nested PCR, using two different primer pair sets, designed via the multiple alignment of nucleotide sequences obtained from the 13 mycoplasmal species. The nested PCR, which generated DNA fragments of 165-353 bp, was found to be able to detect 1-2 copies of the target DNA, and evidenced no cross-reactivity with the generated DNA of related microorganisms or of human cell lines, thereby confirming the sensitivity and specificity of the primers used. The identification of contaminated species was' achieved via the performance of restriction fragment length polymorphism (RFLP) coupled with Sau3AI digestion. The results obtained in this study furnish evidence suggesting that the employed assay system constitutes an effective tool for the disagnosis of mycoplasmal contamination in cell culture systems.

• Journal of Microbiology and Biotechnology
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• v.23 no.10
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• pp.1484-1490
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• 2013

A lack of investigation in specific regions has impeded the understanding of epidemiological trends in the prevalence of sexually transmitted infections (STIs) in South Korea. To help fill this research gap, this study used multiplex polymerase chain reaction (mPCR) to determine the prevalence of STIs detected in clinical specimens collected from women in Cheonan, South Korea between August 2006 and November 2012, and analyzed the prevalence of STIs according to age, bacterial pathogen, and time period. Of the 1,618 specimens collected from 1,523 patients, 536 (35.2%) tested positive for at least 1 pathogen, with 407 (25.2%) testing positive for 1 pathogen, 103 (6.4%) for 2 pathogens, 20 (1.2%) for 3 pathogens, and 6 (0.4%) for 4 pathogens (n = 697 pathogens total). The median ages of all patients and of STI-positive patients were 37.8 and 33.3 years, respectively, and both decreased annually over the study period. Mycoplasma hominis (MH) was detected in 62.1% of the positive specimens, Ureaplasma urealyticum (UU) in 28.4%, Chlamydia trachomatis (CT) in 23.1%, Trichomonas vaginalis (TV) in 7.8%, Mycoplasma genitalium (MG) in 6.5%, and Neisseria gonorrhoeae (NG) in 2.1%. Whereas the prevalence of MH, MG, and TV infection did not vary greatly over the study period, that of UU decreased by one-fifth and that of both CT and NG increased 4-fold. The results indicate great variability in the rates of infection with each pathogen and a decreasing trend in overall STI prevalence, age of patients seeking STI testing, and age of STI-positive patients.

• Microbiology and Biotechnology Letters
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• v.46 no.4
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• pp.425-429
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• 2018

Ureaplasma urealyticum (UU) infection can spread rapidly across populations and is associated with cervical intraepithelial neoplasms, human papillomavirus infections, and newborn mortality. This study aimed to provide information that could be used to protect public health and decrease the incidence and transmission of sexually transmitted infections (STIs), particularly among childbearing women. We examined the epidemiology of UU infection in Cheonan, South Korea. During 2006-2017, 4,050 specimens were submitted for STI screening using a multiplex polymerase chain reaction (PCR) assay. Data were analyzed for UU infection cases using the R statistical program and categorical data were analyzed using the chi-square test, and p-values <0.05 were considered statistically significant. Positive PCR results were shown in 17.8% of the total specimens, in 9.0% of men, and in 18.7% of women. Individuals in their teenaged years and individuals aged 20-29 years accounted for the largest proportions of UU-positive specimens. Although Mycoplasma hominis was the most prevalent bacterium in 2006, it was superseded by UU in 2017. Of the 870 UU-positive specimens, 50.1%, 33.1%, 13.4%, and 2.8% had single, double, triple, and quadruple infection, respectively. UU was most common among Korean individuals aged 20-29 years, indicating a high risk of maternal-to-infant transmission that should be addressed through rapid diagnosis, treatment, and management.

• Microbiology and Biotechnology Letters
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• v.50 no.2
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• pp.270-276
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• 2022

This study analyzed the epidemiological trends of sexually transmitted infections (STIs) according to age and sex among individuals aged 50 years or older in South Korea from September 2018 to December 2020. We found that the positivity rate for Gardnerella vaginalis was the highest in the study group, followed by the positivity rate for Ureaplasma parvum (UP). Interestingly, the positivity rates for Mycoplasma hominis and UP were higher in female participants than in male participants. The positivity rate for Treponema pallidum was very low in the female participants. During the study period, the positivity rate for herpes simplex virus 2 increased in the female participants, while the positivity rate for Candida increased in the male participants. These results show that the STI positivity rate varies according to age and sex, and a difference was observed in the average age of positive participants according to the type of STIs. We found a clear pattern of infection in the elderly population and according to sex. Our findings are expected to be used as baseline data for future research, education, and prevention of STIs in the elderly population.

• Parasites, Hosts and Diseases
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• v.54 no.1
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• pp.75-80
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• 2016

This study explored epidemiological trends in trichomoniasis in Daegu, South Korea. Wet mount microscopy, PCR, and multiplex PCR were used to test for Trichomonas vaginalis in vaginal swab samples obtained from 621 women visiting 2 clinics in Daegu. Of the 621 women tested, microscopy detected T. vaginalis in 4 (0.6%) patients, PCR detected T. vaginalis in 19 (3.0%) patients, and multiplex PCR detected T. vaginalis in 12 (1.9%) patients. Testing via PCR demonstrated high sensitivity and high negative predictive value for T. vaginalis. Among the 19 women who tested positive for T. vaginalis according to PCR, 94.7% (18/19) reported vaginal signs and symptoms. Notably, more than 50% of T. vaginalis infections occurred in females younger than 30 years old, and 58% were unmarried. Multiplex PCR, which simultaneously detects pathogens from various sexually transmitted infections, revealed that 91.7% (11/12) of patients were infected with 2 or more pathogens. Mycoplasma hominis was the most prevalent co-infection pathogen with T. vaginalis, followed by Ureaplasma urealyticum and Chlamydia trachomatis. Our results indicate that PCR and multiplex PCR are the most sensitive tools for T. vaginalis diagnosis, rather than microscopy which has been routinely used to detect T. vaginalis infections in South Korea. Therefore, clinicians should take note of the high prevalence of T. vaginalis infections among adolescent and young women in order to prevent persistent infection and transmission of this disease.