• Journal of Microbiology and Biotechnology
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• v.31 no.8
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• pp.1109-1114
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• 2021

Chlamydia pneumoniae is a type of pathogenic gram-negative bacteria that causes various respiratory tract infections including asthma. Chlamydia species infect humans and cause respiratory infection by rupturing the lining of the respiratory which includes the throat, lungs and windpipe. Meanwhile, the function of interleukin-4 (IL-4) in Ch. pneumoniae respiratory infection and its association with the development of airway hyperresponsiveness (AHR) in adulthood and causing allergic airway disease (AAD) are not understood properly. We therefore investigated the role of IL-4 in respiratory infection and allergy caused by early life Chlamydia infection. In this study, Ch. pneumonia strain was propagated and cultured in HEp-2 cells according to standard protocol and infant C57BL/6 mice around 3-4 weeks old were infected to study the role of IL-4 in respiratory infection and allergy caused by early life Chlamydia infection. We observed that IL-4 is linked with Chlamydia respiratory infection and its absence lowers respiratory infection. IL-4R α2 is also responsible for controlling the IL-4 signaling pathway and averts the progression of infection and inflammation. Furthermore, the IL-4 signaling pathway also influences infection-induced AHR and aids in increasing AAD severity. STAT6 also promotes respiratory infection caused by Ch. pneumoniae and further enhanced its downstream process. Our study concluded that IL-4 is a potential target for preventing infection-induced AHR and severe asthma.

• Journal of Microbiology and Biotechnology
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• v.26 no.4
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• pp.790-798
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• 2016

Chlamydiae, obligate intracellular bacteria, are associated with a variety of human diseases. The chlamydial life cycle undergoes a biphasic development: replicative reticulate bodies (RBs) phase and infectious elementary bodies (EBs) phase. At the end of the chlamydial intracellular life cycle, EBs have to be released to the surrounded cells. Therefore, the interactions between Chlamydiae and cell death pathways could greatly influence the outcomes of Chlamydia infection. However, the underlying molecular mechanisms remain elusive. Here, we investigated host cell death after Chlamydia infection in vitro, in L929 cells, and showed that Chlamydia infection induces cell necrosis, as detected by the propidium iodide (PI)-Annexin V double-staining flow-cytometric assay and Lactate dehydrogenase (LDH) release assay. The production of reactive oxygen species (ROS), an important factor in induction of necrosis, was increased after Chlamydia infection, and inhibition of ROS with specific pharmacological inhibitors, diphenylene iodonium (DPI) or butylated hydroxyanisole (BHA), led to significant suppression of necrosis. Interestingly, live-cell imaging revealed that Chlamydia infection induced lysosome membrane permeabilization (LMP). When an inhibitor upstream of LMP, CA-074-Me, was added to cells, the production of ROS was reduced with concomitant inhibition of necrosis. Taken together, our results indicate that Chlamydia infection elicits the production of ROS, which is dependent on LMP at least partially, followed by induction of host-cell necrosis. To our best knowledge, this is the first live-cell-imaging observation of LMP post Chlamydia infection and report on the link of LMP to ROS to necrosis during Chlamydia infection.

• Clinical and Experimental Pediatrics
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• v.52 no.3
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• pp.277-282
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• 2009

Pneumonia, which usually requires hospitalization for children, is caused by various pathogens. According to recent surveys, the prevalence of atypical pneumonia caused by Mycoplasma or Chlamydia has increased, especially in preschool children. Also, the evidence has been accumulated that Mycoplasma or Chlamydia infection is associated with asthma including both inception and exacerbation. Therefore, it is important to consider how the clinical aspects of Mycoplasma pneumonia have changed. In particular, Chlamydia pneumonia, which has not been prevalent in Korea, needs greater attention.

• Journal of Yeungnam Medical Science
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• v.6 no.2
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• pp.23-28
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• 1989

After application of silver nitrate on every newborn, the incidence of gonococcal conjunctivitis was markedly decreased. But recently neonatal conjunctivitis due to chlamydia infection is increasing, so clinical observation was made on 26 newborn infants who showed eye discharge from June 1st to August 31st 1989. The results were as follows. 1. The incidence of chlamydia infection among neonatal Conjunctivitis was 34.6%. 2. The most common age at diagnosis was 6-15days of life and there was no sexual prepondrance. 3. There was no significant difference on clinical symptoms between chlamydia conjunctivitis and other Conjunctivitis. 4. Of 26 infants examined. 16 cases revealed no growth on routine bacterial culture. Of the organism cultured, P. aeruginosa was the most common agent(19.2%) and followed by S. aureus(11.5%) and S. epidermidis(7.6%). In one case of chlamydia I conjunctivitis, there was concurrent S. aureus infections. 5. On this study, Giemsa stain did not give significant diagnostic aid of chlamydia conjunctivitis.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.3
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• pp.1497-1500
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• 2014

Cervical cancer continues to be an important public health problem in Thailand. While the high risk human papillomavirus (HPV) types have been established as the principle causative agent of both malignancies and the precursor lesions, cervical intraepithelial neoplasia (CIN), other factors may also be involved like other sexually transmitted diseases, as well as smoking. Chlamydia trachomatis is an obligate intracellular Gramnegative bacterium which has a tendency to cause chronic infection featuring inflammation and therefore might be expected to increase the risk of cervical cancer. In the present nested case-control study, 61 cases of cervical cancer and 288 matched controls with original serum samples were identified from the Khon Kaen Cohort, established in the North-East of Thailand, by linkage to the Khon Kaen population based cancer registry. C. trachomatis specific IgG antibodies at recruitment were measured by microimmunofluorescence and assessed for association with cervical cancer using STATA release10. No significant link was noted either with all cancers or after removal of adenocarcinomas. The results suggest no association between Chlamydia infection and cervical cancer development in North-East Thailand, but possible influencing factors must be considered in any future research on this topic.

• The Journal of the Korean Society for Microbiology
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• v.21 no.2
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• pp.261-270
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• 1986

A total of 339 urethral, vaginal swab and eye discharge materials from the out-patients in the hospitals of Seoul area was microbiologically collected for the detection of Chlamydia trachomatis infection during May through August, 1985. McCoy cell culture system (MCC) and enzyme-likned immunosorbent assay (EIA) methods were employed in this study as the tools for the detection of C. trachomatis, and the detectabilities of two methods were compared. The results obtained in this study are summarized as follows: 1. The positive rate of C. trachomatis in 339 swab specimens was 18.6%, and the rate in females (20.1%) was much higher than that in males (7.1%). 2. The positive rate of C. trachomatis infection the prostitutes was the highest (24.2%), and the rate in the eye discharge specimens obtained from the new barns was 12.8%. 3. The positive rates of C. trachmoatis infection detected in the specimens from the patients with vaginitis and leucorrhea, with infertility, with cystitis and with nongonococcal urethritis were 17.2%, 21.9%. 18.0% and 7.1%, respectively. 4. The positive rate of C. trachomatis infection in 20-25 age group was 30.5%. This rate was the highest among the other age groups. 5. The positive rate of C. trachomatis infection in the randomly screened 89 swab specimens by EIA (30.3%) was much higher than the rate detected by MCC (18.6%). 6. The positive rate of C. trachomatis infection in females detected by EIA was also much higher than in males, and the 20-25 age group showed the highest positive rate as compared to the other age groups. 7. Sensitivity and specificity of EIA for the detection on C. trachomatis were 100% and 88.6%, respectively, in case that MCC was regarded as perfect method. In summarizing the above results, it is known that considerable cases with genital diseases and with eye discharges were associated with C. trachomatis, and that EIA method is recommendable for the detection of C. trachomatis especially in the specimens swabed from the genital tracts.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.6
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• pp.2819-2822
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• 2012

Objective: To assess induction effects of Chlamydia pneumoniae (Cpn) on lung cancer in rats. Methods: A lung cancer animal model was developed through repeated intratracheal injection of Cpn (TW-183) into the lungs of rats, with or without exposure to benzo(a)pyrene (Bp). Cpn antibodies (Cpn-IgA, -IgG, and -IgM) in serum were measured by microimmunofluorescence. Cpn-DNA or Cpn-Ag of rat lung cancer was detected through polymerase chain reaction or enzyme-linked immunosorbent assay. Results: The prevalence of Cpn infection was 72.9% (35/48) in the Cpn group and 76.7% (33/43) in the Cpn plus benzo(a)pyrene (Bp) group, with incidences of lung carcinomas in the two groups of 14.6% (7/48) and 44.2% (19/43), respectively (P-values 0.001 and <0.000 compared with normal controls). Conclusions: A rat model of lung carcinoma induced by Cpn infection was successfully established in the laboratory for future studies on the treatment, prevention, and mechanisms of the disease.

• Journal of Microbiology
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• v.41 no.2
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• pp.137-143
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• 2003

The present study was performed to identify pathogenic factors of Chlamydia trachomatis, which invade the host cell membrane. We prepared monoclonal antibody against C. trachomatis and searched for pathogenic factors using this antibody, and subsequently identified the surface components of the elementary body of C. trachomatis, i.e., major outer membrane protein (MOMP), lipopolysaccharide (LPS), and two other surface exposure proteins. These proteins are believed to be important in the pathogenesis of host cell chlamydial infection. Additionally, to identify factors related to the host cell and C. trachomatis, we prepared C. trachomatis infected and non-infected McCoy cell extracts, and reacted these with anti-chlamydial LPS monoclonal antibody. We found that anti-chlamydial LPS monoclonal antibody reacted with a 116 kDa proteinaceous McCoy cell membrane component.

• Clinical and Experimental Pediatrics
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• v.51 no.7
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• pp.729-735
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• 2008

Purpose : Chlamydia trachomatis is one of the most common sexually transmitted diseases and is also a cause of pneumonia in infants. Respiratory infections by respiratory viruses are also common for infants. The objectives of this study were to identify the clinical manifestations and to determine the prevalence of C. trachomatis respiratory infections and coinfections by respiratory viruses in infants younger than 6 months of age. Methods : For this study, we enrolled 6 months or younger infants who were admitted to the Dankook University Hospital between January 2002 and July 2007, with respiratory symptoms. Nasopharyngeal aspirates or throat swabs were collected within s d of hospitalization and C. trachomatis was detected using polymerase chain reaction (PCR). Patients who tested positive underwent multiplex PCR for respiratory viruses. Results : A total of 690 patients underwent chlamydial PCR testing and 36 (5.2%) had positive results. Of the 36, 28 (78%) were male; 30 were vaginally delivered. From the 36 patients positive for C. trachomatis, 26 underwent multiplex respiratory viral PCR; 12 were coinfected with viruses. Respiratory syncytial virus (RSV) was the most frequent pathogen that was detected in 6 patients. Increased C-reactive protein and fever were significant in patients coinfected with respiratory viruses. Conclusion : C. trachomatis can infected in infants delivered by cesarean section as well as in 6 months old or younger infants. Infant with C. trachomatis respiratory infections can also be coinfected with respiratory infection also coinfected with respiratory viruses. Further studies are needed to better understand the prevalence rates of the this infection and its coinfection rate with respiratory viruses.

• Tuberculosis and Respiratory Diseases
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• v.69 no.6
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• pp.426-433
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• 2010

Background: Persistent cough has recently been found to be associated with Chlamydia pneumoniae infection. We aimed to investigate the infection rate of C. pneumonia in adult patients with chronic cough. Methods: We recruited 68 patients with persistent cough lasting in excess of 3 weeks, who visited Kangdong Sacred Heart Hospital from January 2005 to August 2005. On the first visit, chest and paranasal sinuses radiography, skin prick test of common allergens, and induced sputum samples for C. pneumoniae were performed in all of patients. Further evaluation for diagnosis included a methacholine provocation test and eosinophil counts in induced sputum. Results: The most common cause of chronic cough was upper airway cough syndrome (UACS) (26.5%), followed by eosinophilic bronchitis (20.6%) and cough variant asthma (16.2%). Idiopathic chronic cough was the cause in 33.8% of patients. The mean duration of cough was 11.7 months. C. pneumoniae was isolated by polymerase chain reaction (PCR) from one patient who had upper respiratory air way syndrome. Conclusion: Chlamydia pneumoniae appears to have a minor role as a cause of chronic cough in patients.