• Clinical and Experimental Pediatrics
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• v.56 no.9
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• pp.411-415
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• 2013

Infectious diseases precede a significant proportion of acute ischemic strokes in children. Here, we report a case of acute ischemic stroke in a 3-year-old girl with a Mycoplasma pneumonia-associated respiratory tract infection. She developed an acquired prothrombotic state of protein S deficiency and had increased fibrinogen and fibrinogen degradation product levels and increased titer of antinuclear antibodies. However, these conditions were completely alleviated at the 1-month follow-up examination. Infection with M. pneumoniae may cause a transient prothrombotic state that can potentially cause a thrombus.

• Parasites, Hosts and Diseases
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• v.58 no.5
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• pp.565-569
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• 2020

This report describes the first clinical case of a transfusion-associated Mycoplasma haemocanis infection in a dog in Korea. A 6-year-old male Maltese underwent a red blood cell transfusion for idiopathic immune-mediated hemolytic anemia. Eighteen days after the blood transfusion, the recipient's packed cell volume decreased and basophilic organisms were found on erythrocytes. A polymerase chain reaction and sequential analysis showed that both the donor dog and recipient dog had M. haemocanis. Six weeks after doxycycline administration, no organisms were detected and the recipient's anemia had improved.

• BMB Reports
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• v.52 no.8
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• pp.490-495
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• 2019

Using tunneling nanotubes (TNTs), various pathological molecules and viruses disseminate to adjacent cells intercellularly. Here, we show that the intracellular invasion of Mycoplasma hyorhinis induces the formation of actin- and tubulin-based TNTs in various mammalian cell lines. M. hyorhinis was found in TNTs generated by M. hyorhinis infection in NIH3T3 cells. Because mycoplasma-free recipient cells received mycoplasmas from M. hyorhinis-infected donor cells in a mixed co-culture system and not a spatially separated co-culture system, direct cell-to-cell contact via TNTs was necessary for the intracellular dissemination of M. hyorhinis. The activity of Rac1, which is a small GTP binding protein, was increased by the intracellular invasion of M. hyorhinis, and its pharmacological and genetic inhibition prevented M. hyorhinis infection-induced TNT generation in NIH3T3 cells. The pharmacological and genetic inhibition of Rac1 also reduced the cell-to-cell dissemination of M. hyorhinis. Based on these data, we conclude that intracellular invasion of M. hyorhinis induces the formation of TNTs, which are used for the cell-to-cell dissemination of M. hyorhinis.

• Clinical and Experimental Pediatrics
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• v.64 no.9
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• pp.459-467
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• 2021

Mycoplasma pneumoniae (MP) is the most common cause of childhood bacterial pneumonia. Although macrolide is known to be effective as a first-line therapy, the proportion of macrolide resistance in MP pneumonia has strikingly increased during recent 2 decades in East Asia. This is challenging to physicians since they have to decide more often whether to use secondary treatment. Diagnostic methods to detect macrolide-resistance of MP are currently not available in Korean hospitals. Even in the diagnosis of MP infection, both serologic and molecular test have limitation: inability to differentiate current illness from carriage or asymptomatic infection. Combining these 2 diagnostic methods and excluding infection caused by other respiratory pathogens allow a more reliable diagnosis. This effort is even more demanding in recent years to keep children from unnecessary exposure to secondary antibiotics. Although several observational studies have reported that tetracycline and fluoroquinolone, which are considered in the treatment of refractory MP pneumonia, have efficacy of shortening the duration of fever and respiratory symptoms, those findings need to be proven by well-designed prospective studies. The use of tetracycline and fluoroquinolone in children is generally tolerable, as supported by many observational data. However, since concerns about side effects still remain, careful consideration about benefits and risks is needed to decide their use.

• Clinical and Experimental Pediatrics
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• v.45 no.10
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• pp.1227-1233
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• 2002

Purpose : Several studies have shown that increases of eosinophil markers are common findings of asthma and Mycoplasma pneumoniae infection, and eosinophil markers reflect the clinical stage of asthma. The purpose of this study was to investigate the change of eosinophil markers according to the clinical stage of Mycoplasma pneumonia. Methods : The patient group consisted of 33 outpatient children with Mycoplasma pneumonia. Peripheral blood total eosinophil count(TEC) and serum eosinophilic cationic protein(ECP) level were measured at both acute and recovery stages and were compared between both stages. The patient group was subdivided into the wheezing(n=16) and the nonwheezing group(n=17), and the TECs and the ECPs of one group were compared with those of the other group. The correlation between Mycoplasma antibody titer and the eosinophil markers of acute stage were analyzed. Results : In the whole patient group, the TECs and the ECPs of the acute stage were significantly higher than those of the recovery stage(P=0.018, P=0.005), but there were no differences in the TEC and the ECP between the wheezing and the nonwheezing group. In the wheezing group, there were no significant differences in the TEC and the ECP between acute and recovery stages. There were no correlations between acute stage Mycoplasma antibody titer and the eosinophil markers. Conclusion : Eosinophil markers reflect the clinical stage of Mycoplasma pneumonia and eosinophilic inflammations may continue even after the acute stage in wheezing patients with Mycoplasma pneumonia.

• Tuberculosis and Respiratory Diseases
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• v.39 no.2
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• pp.194-198
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• 1992

Mycoplasma pneumoniae produces illness in man ranging from mild upper respiratory tract infection to severe bronchitis and pneumonia. We experienced a case of mycoplasma pneumonia complicated with acute respiratory failure, cold agglutinin hemolytic anemia, pleural effusion, Raynaud's phenominon and hepatitis in 27-year-old female. She was diagnosed as having mycoplasma pneumonia by detecting mycoplasma antibody and cold agglutinin test and treated effectively with erythromycin.

• Pediatric Infection and Vaccine
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• v.4 no.2
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• pp.271-275
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• 1997

We experienced a case of Henoch-Sch$\ddot{o}$nlein purpura associated with Mycoplasma pneumoniae pneumonia in a 28 month old male who suffered from cough, abdominal pain and both leg swelling and pain. Physical examination showed varying sized purpura, characteristic of Henoch-Sch$\ddot{o}$nlein purpura, below both knee. Laboratory test revealed Mycoplasma pneumoniae antibody titer >1:2,560 and cold agglutinins titer 1:64. Chest X-ray showed peribronchial blurring in both lung fields. The patient was treated with midecamycin and prednisolone for 7 days and responded to the treatment well. The authors report a case of Henoch-Sch$\ddot{o}$nlein purpura with Mycoplasma pneumoniae pneumonia with brief review of related literatures.

• Korean Journal of Veterinary Service
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• v.22 no.1
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• pp.9-13
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• 1999

Mycoplasmal pneumonia of swine(MPS) cause by Mycoplasma hyopneumoniae has been recognized as a serious impediment to swine production due to chronic respiratory disorder which result in the weight loss and decreased feed conversion. The disease causes a great economic losses in pig industry by characterizing with high morbidity, low mortality, growth retardation and low feed efficiency. The present study was conducted to investigate the titers of antibody against M hyopneumoniae from the regional and seasonal groups of the slaughtered pigs by enzyme-linked immunosorbent assay(ELISA). The result have shown that the average seropositive rate of M hyopneumoniae infection was 84.6% . The regional seropositive rate in Korea showed 87.4% in Kyonggj, 83.4n in Kangwon, 89.2% in Chungnam and 77.6% in Chungbuk area, respectively. Also the seasonal seropositive rate was appeared as 78.6% in spring,90.1% in summer, 76.9% in autumn and 83.8% in winter, respectively.

• Clinical and Experimental Pediatrics
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• v.55 no.2
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• pp.42-47
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• 2012

$Mycoplasma$ $pneumoniae$ (MP), the smallest self-replicating biological system, is a common cause of upper and lower respiratory tract infections, leading to a wide range of pulmonary and extra-pulmonary manifestations. MP pneumonia has been reported in 10 to 40% of cases of community-acquired pneumonia and shows an even higher proportion during epidemics. MP infection is endemic in larger communities of the world with cyclic epidemics every 3 to 7 years. In Korea, 3 to 4-year cycles have been observed from the mid-1980s to present. Although a variety of serologic assays and polymerase chain reaction (PCR) techniques are available for the diagnosis of MP infections, early diagnosis of MP pneumonia is limited by the lack of immunoglobulin (Ig) M antibodies and variable PCR results in the early stages of the infection. Thus, short-term paired IgM serologic tests may be mandatory for an early and definitive diagnosis. MP infection is usually a mild and self-limiting disease without specific treatment, and if needed, macrolides are generally used as a first-choice drug for children. Recently, macrolide-resistant MP strains have been reported worldwide. However, there are few reports of apparent treatment failure, such as progression of pneumonia to acute respiratory distress syndrome despite macrolide treatment. The immunopathogenesis of MP pneumonia is believed to be a hyperimmune reaction of the host to the insults from MP infection, including cytokine overproduction and immune cell activation (T cells). In this context, immunomodulatory treatment (corticosteroids or/and intravenous Ig), in addition to antibiotic treatment, might be considered for patients with severe infection.

• Pediatric Infection and Vaccine
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• v.6 no.1
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• pp.78-85
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• 1999

Purpose : Mycoplasma pneumoniae pneumonia has been to be developed frequently in school age children and adolescence and hard to see under 3 year-old children. But it seems to be increased in number of patients with Mycoplasma pneumoniae pneumonia under 3-year old in clinical practice in these days. We have aimed to examine the characteristics of clinical findings of Mycoplasma pneumonia under 3 year-old children. Methods : We had performed retrospective review of medical records of 30 patients with Mycoplasmal pneumonia under 3-year old children who admitted to Department of Pediatrics, Kyunghee University Hospital from Jan. 1994 to Dec. 1997. The diagnostic criteriae was Cold agglutinin titer>1:64 or Mycoplasma antibody titer>1:80. Results : Mycoplasmal pneumonia was 30 out of 235 cases(12.7%) of total pneumonia under 3 year old children. Male female ratio was 1.3 : 1 and age distributions were 0~1y : 0, 1~2y : 8, 2~3y : 22 cases. Clinical symptoms and signs were cough(100.0%), sputum(83.3%), fever(80.0%) rhinorrhea(33.3%), vomiting(33.3%), moist rale(86.7%), decreased breathing sound(26.7%), wheezing(20.0%), and pharyngeal injection(30.0%). Thirteen out of 30 cases(43.3%) had unilateral infiltration, 10 cases(33.4%) had bilateral infiltration, 1 case(3.3%) had pleural effusion, and 6 cases(20.0%) had negative findings on chest radiography and there was no cases of atelectasis. On laboratory findings, 6 out of 30 cases(20.0%) had leukocytosis, 1 case(3.3%) had neutrophilia, 10 cases(30.0%) had eosinophilia, 17 cases(56.7%) had increased ESR, and 18 cases(60.6%) had positive CRP. Positive cold agglutinin titers(>1 : 64) were 19 cases(63.3%), and positive mycoplasma antibody(M-ab) titers(>1 : 80) were 27 cases(93.3%). Mycoplasma antibody test was more valuable than cold agglutinin test for the diagnosis of Mycoplasmal pneumonia and there was no correlation between cold agglutinin titer and mycoplasma antibody titer. Mycoplasma-polymerase chain reaction(M-PCR) was done with 13 cases, 12 out of 13 cases(92.3%) were positive. M-PCR test was valuable to the diagnosis of Mycoplasmal pneumonia but it will be needed to further study for their clinical application. Among 30 cases, 5 cases(16.7%) had complications, 3 cases(10.0%) had skin rash, 1 case(3.3%) had pleural effusion, 1 case(3.3%) had arthralgia, but all complications were mild and recovered without residual sequelae. Conclusion : The occurrence of Mycoplasmal pneumonia under 3 year-old children was not rare from this study. Clinical characteristics of Mycoplasmal pneumonia under 3-year old were normal radiologic findings in many cases, low complication rate, mild clinical course, and tend to rapid recovery compared with general manifestations of Mycoplasmal infectionsin children and adolescence. There were likely to be missed patients with Mycoplasmal pneumonia which did not diagnose by conventional serologic tests that had low sensitivity and specificity. We have to pay attention to the Mycoplasmal infection of the young children with pneumonia during epidemic periods of Mycoplasmal infection.