[Chlamydia trachomaatis DNA in leukocytes of peripheral blood from neonates]

Chlamydia transmitting from the genital to gastrointestinal tract and inducing tubal disease: Double attack pattern

Chlamydia trachomatis ( CT ) genital tract infection is insidious, and patients often have no conscious symptoms.Delayed treatment after infection can lead to serious complications. Chlamydia muridarum ( CM ) genital tract infection in female mice can simulate CT genital tract infection in women, which is an ideal model to investigate the pathogenesis of CT . CM plasmid protein pGP3, chromosomal protein TC0237/TC0668, CM -specific CD8 + T cells, TNF-α, and IL-13 can induce genital tract inflammation, CD4 + T cells are responsible for CM clearance. However, tubal inflammation persists after genital tract CM is removed. Genital tract CM can spread spontaneously in vivo and colonize the gastrointestinal (GI) tract, but the GI tract CM cannot reverse spread to the genital tract. The survival time and number of CM transmitted from genital tract to GI tract are positively correlated with the long-term lesion of oviduct, while the CM inoculated directly into the GI tract has no pathogenicity in both the genital and GI tract. The double attack pattern of Chlamydia -induced genital tract inflammatory lesions is as follows: CM infection of oviduct epithelial cells initiates the process of oviduct repair as the first attack. After genital CM spreads to the GI tract, activated chlamydia-specific CD8 + T cells are recruited to the genital tract and secreted pro-fibrotic cytokines such as TNF-α and IL-13. This process is called the second attack which transform tubal repair initiated by the first attack into long-term tubal fibrosis/hydrosalpinx. Elucidating the pathogenic mechanism of Chlamydia infection can provide new ideas for the development of Chlamydia vaccine, which is expected to solve the problems of infertility caused by repeated CT infection in women.

Chlamydia Spreading from the Genital Tract to the Gastrointestinal Tract - A Two-Hit Hypothesis

Chlamydia trachomatis, a leading bacterial cause of sexually transmitted infection-induced infertility, is frequently detected in the gastrointestinal tract. Chlamydia muridarum, a model pathogen for investigating C. trachomatis pathogenesis, readily spreads from the mouse genital tract to the gastrointestinal tract, establishing long-lasting colonization. C. muridarum mutants, despite their ability to activate acute oviduct inflammation, are attenuated in inducing tubal fibrosis and are no longer able to colonize the gastrointestinal tract, suggesting that the spread of C. muridarum to the gastrointestinal tract may contribute to its pathogenicity in the upper genital tract. However, gastrointestinal C. muridarum cannot directly autoinoculate the genital tract. Both antigen-specific CD8⁺ T cells and profibrotic cytokines, such as TNFα and IL-13, are essential for C. muridarum to induce tubal fibrosis; this may be induced by the gastrointestinal C. muridarum, as a second hit, to transmucosally convert tubal repairing - initiated by C. muridarum infection of tubal epithelial cells (serving as the first hit) - into pathogenic fibrosis. Testing the two-hit mouse model should both add new knowledge to the growing list of mechanisms by which gastrointestinal microbes contribute to pathologies in extragastrointestinal tissues and provide information for investigating the potential role of gastrointestinal C. trachomatis in human chlamydial pathogenesis.

Eosinophilia in Preterm Born Infants Infected with Chlamydia trachomatis

A higher than 350 eosinophils/mm(3) is strongly associated with Chlamydia trachomatis in term born babies coursing with respiratory distress. However, in preterm newborns infected with this pathogen, the levels of eosinophils are unknown. Forty newborn infants with clinical data of respiratory problems and/or sepsis were analyzed. DNA of leukocytes from peripheral blood was used to identify C. trachomatis. Detection of chlamydial infection was performed by amplifying the ompA gene by an in-house PCR, and eosinophil levels were evaluated in an XT-2000-hematology analyzer. Eighteen infants showed chlamydial infection and 14 of them showed pneumonia (RR = 2.6; CI95% 1.03-6.5; p =.027). Their eosinophil levels were 719 ± 614 cells/mm(3). A significant association between eosinophilia ≥1250 cells/mm(3) and gestational age of less than 29 weeks (RR = 5.8; 1.35; CI95% [1.4-24.5], p <.008) was observed. The preterm infants with chlamydial infection did not show higher eosinophil levels than uninfected infants.