• Clinical and Experimental Pediatrics
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• v.51 no.5
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• pp.533-537
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• 2008

Mycoplasma pneumoniae (M. pneumoniae) infection causes a wide variety of clinical manifestations in children and young adults, the main one being pneumonia. M. pneumoniae is transmitted from person to person by infected respiratory droplets. Symptoms caused by M. pneumoniae infection can be divided into those involving the respiratory tract, and those caused by extrapulmonary disease. M. pneumoniae infections may cause central nervous system (CNS) complications-with encephalitis being the most frequent-and stroke being a rare complication. The pathogenesis of the CNS disease is unclear; possibilities include direct infection and an immune-mediated reaction. We present two cases of CNS complications subsequent to infection with M. pneumoniae; both cases had convincing evidence of preceding M. pneumoniae respiratory disease with no evidence of viable M. pneumoniae in the cerebrospinal fluid. We report cases of encephalitis and stroke following a recent M. pneumoniae infection.

• Korean Journal Plant Pathology
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• v.1 no.3
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• pp.184-189
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• 1985

Transmission of mulberry dwarf mycoplasma (MDM) from diseased mulberry to 5 herbaceous plants (periwinkle, white clover, Ladino clover, red clover, and Chinese milk vetch) through insect vector, Hishimonus sellatus, was confirmed by symptom expression and microscopic evidences. The earliest symptom appearance was noticed on periwinkle in which incubation period was 25-30 days, while it ranged 35-40 days in the other plant species. The common symptoms of MDM infected plants were characterized by poor plant growth with accompanying discolorations of leaves (chlorosis with vein clearing in periwinkle, reddish in red clover, brownish in white and Ladino clovers, and yellowish in Chinese milk vetch). Mycoplasmal infections were diagnosed light microscopically by Dienes' and toluidine blue staining of hand-cut and Epon-embedded sections, respectively. In Dienes' stain, all the plants infected with MDM showed specific staining reaction in phloems. In toluidine blue stain, mycoplasmal existence was noted by granular appearance in sieve tubes which were confirmed to be mycoplasma-like organisms under an electron microscope.

• Korean Journal of Veterinary Service
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• v.33 no.1
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• pp.45-50
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• 2010

Mycoplasma gallisepticum (MG) is major cause of chronic respiratory disease in chickens. M. synoviae (MS) most frequently occurs a subclinical upper respiratory infection but may result in airsacculitis and synovitis in chickens and turkeys. Both mycoplasmas induce economic losses by triggering chronic respiratory signs, airsacculitis and decreased egg production. For prevention of the infections, live attenuated andinactivated vaccines are commercially used for prevention of MG but not MS in Korea. Serum plate agglutination (SPA) and enzyme-linked immunosorbent assay (ELISA) have been commonly used for serological diagnosis for MG and MS. Recently, it is believed that MS spread in chickens is very seriously in Korea and respiratory infection with MS causes substantial loss in poultry farms. In this study, we investigated the serological prevalence of MG and MS in unvaccinated chickens between 2008 and 2009. The overall seroprevalence of MG was 24% of 2,094 for individual chickens and 24% of 189 farms. The overall seroprevalence of MS was 36% in 2,095 chickens and 39% in 198 farms. The results show that seropositive ratio of MS is higher than MG. The geographical prevalence of MG has been estimated in following sequence; Gangwon, Jeolla, Gyeonggi, Gyeongsang, and Chungcheong. The geographical prevalence of MS has been estimated as follows; Gangwon, Gyeonggi, Gyeongsang, Chungcheong, and Jeolla. Seasonal seroprevalencewas also examined, and it found that seroprevalence in spring, fall and winter was higher than that in summer in MG, but not in MS. No significant difference was shown in seroprevalence according to breed. Future study about pathogenicity of MS isolates would be needed and economical losses by MS outbreaks should be analyzed. Moreover, we compared sero-positivity obtained with SPA and ELISA. The kappa value of MG between SPA and ELISA was 0.8061 and the kappa value of MS between SPA and ELISA was 0.7649.

• Korean Journal of Veterinary Research
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• v.39 no.6
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• pp.1218-1223
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• 1999

The purposes of this study are to examine seroprevalence of Mycoplasma hyopneumoniae infection in pigs of different age groups, and retrospectively determine if nursery depopulation (ND) could influence the seroprevalence of M hyopneumoniae infection in nurseries. Sera of 4, 8, 12, 16, and 20 weeks old pigs from 7 farms were first selected from a serum bank to examine serologic profiles for M hyopneumoniae infections. Availability of representative sera in the serum bank was a major criterion for farm selection. The sera were tested for M hyopneumoniae antibodies by an enzyme linked immunosorbent assay (ELISA) using Tween-20 extracted antigen. Serum samples were also selected from 15 of 34 swine farms that previously participated in a ND study. In order to evaluate M hyopneumoniae infection following ND, ELISA was performed with sera of 8~10 weeks old nursery pigs collected prior to and after ND for up to 12 months from the 15 farms. Serological profiles showed positive ELISA titers for 2 of 7 farms at 8 weeks, 4 of 7 farms at 12 weeks, 6 of 7 farms at 16 weeks, 6 of 6 farms at 20 weeks of age. Prior to ND, 11 of the 15 farms had positive titers in sera of 8~10 weeks old pigs. Sera of 8~10 weeks old pigs collected from 7 of the 11 farms (63.6%) were ELISA antibody negative for up to 12 months following ND. In conclusion, seroconversion to M hyopneumoniae was detected commonly between 10~16 weeks of age, indicating the occurrence of natural infection during the nursery age. The ND appeared to be an effective method to prevent M hyopneumoniae infection within the nursery pig in some farms.

• Pediatric Infection and Vaccine
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• v.16 no.1
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• pp.92-96
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• 2009

Mycoplasma pneumoniae is a common cause of respiratory tract infections. M. pneumoniae infection frequently manifests with extrapulmonary symptoms such as central nervous system complications, skin or mucosal involvement, and gastrointestinal problems. However, cardiac complications associated with M. pneumoniae are rarely reported. We report the case of a 47-month-old girl who died of fulminant myocarditis associated with M. pneumoniae pneumonia.

• 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.

• 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.

• Journal of Microbiology and Biotechnology
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• v.28 no.10
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• pp.1730-1735
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• 2018

Bacterial pneumonia is one of the most common causes of mortality in Korea. In 2016, the mortality rate from pneumonia was 16,476 deaths per 100,000, which was an 11% increase from the previous year. The aim of our study was to determine the distribution of the bacterial pathogens causing respiratory symptoms in different age groups over a 10-year period. Between January 2008 and September 2017, 1,861 specimens from 1,664 patients admitted to Dankook University Hospital with respiratory symptoms were examined. We used multiplex polymerase chain reaction (PCR) to detect six bacterial pneumonia pathogens: Bordetella pertussis, Chlamydophila pneumoniae, Haemophilus influenzae, Legionella pneumophila, Mycoplasma pneumoniae, and Streptococcus pneumoniae. We detected bacterial pneumonia pathogens in 1,281 (68.83%) specimens. Of the 1,709 pathogens detected, S. pneumoniae was the most common (48.57%; n = 830) followed by H. influenzae (40.08%; n = 685). Most infections were found among children younger than 10 years (92.69%; n = 1,584). Although S. pneumoniae was the most common pathogen detected in all age groups, M. pneumoniae infection increased in prevalence with age (p < 0.05). The rate of co-infection was also high among these patients (31.1%; n = 399), which peaked in 2015 (54.55%; n = 42/77). The prevalence of bacterial pneumonia in Cheonan, along with the proportion of co-infections among patients increased over the 10-year study period. The findings will aid the development of treatment and prevention guidelines.

• 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.

• Proceedings of the Korean Society of Veterinary Pathology Conference
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• 2003.10a
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• pp.29-29
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• 2003

Mycoplasma hyopneumoniae is among the most prevalent and important infectious agents associated with porcine respiratory disease complex. The airway dagame caused by M. hyopneumoniae adversely affect the pulmonary host defense mechanisms and may lead to secondary bacterial infections. Culture is considered to be the "gold standard" for diagnosis but this is a very slow and labor-intensive procedure. Isolation of M. hyopneumoniae is complicated by its fastidious nature and extremely slow growth. Thirty days of incubation may be necessary to detect the organism in primary broth cultures. The purposes of the study were (ⅰ) to develop nested PCR for the detection of M. hyopneumoniae for the detection of M. hyopneumoniae DNA in the formalin-fixed, paraffin-embedded lung tissues from experimentally and naturally infected pigs and (ⅱ) to compare the utility of nested PCR with in situ hybridization. (omitted)