Aim. To determine the frequency of detection of conjunctival C. trachomatis (CT), M. hominis (MH), and U. urealyticum (UU) infections in young adults with dry eye disease (DED), since these infections may potentially produce the chronic subclinical inflammation characteristic of DED. Materials and Methods. The study included subjects of 25–45 years of age, divided into the DED (n = 114) and nondry eye control (n = 98) groups, with the diagnosis based on self-reported complaints, biomicroscopy, the Schirmer I test, and break-up time. All patients had conjunctival scrapings taken to detect CT, MH, and UU with direct fluorescent-antibody assay kits. Results. At least one of the three microorganisms was found in 87.7% of the DED patients versus 8.2% of the controls. Of all the DED patients, 63.2%, 50.8%, and 42.1% were found to be infected with CT, MH, and UU, respectively. Multiple pathogens were identified in 65% of the DED patients found to be infected. CT infection was detected in 6.1% of the controls. Conclusion. C. trachomatis, M. hominis, and U. urealyticum were detected with high frequency in the conjunctiva of young adults with DED and may be an important risk factor for DED in them.
PurposeLittle is known about the susceptibility of posterior segment tissues, particularly the human retinal pigment epithelium (hRPE), to Chlamydia trachomatis. The purpose of the study was to investigate the possibility of infecting the hRPE with Chlamydia trachomatis, and to examine the infectivity of different Chlamydia trachomatis clinical isolates for hRPE cells and the hRPE cell response to the infection.MethodsCultured hRPE and McCoy cells were inoculated with eight Chlamydia trachomatis (serovar E) clinical isolates at multiplicity of infection (MOI) of 2.0 or 0.3. To detect Chlamydia trachomatis, samples were stained immunohistochemically with anti-major outer membrane protein antibodies at 24h, 48h, and 72h postinoculation (PI). The changes in the expression of signaling molecules and proteins of cytoskeleton and extracellular matrix in hRPE cells were examined immunohistochemically.ResultsAll eight clinical isolates demonstrated ability to infect hRPE cells. At equal MOI of 0.3, the infectivity of Chlamydia trachomatis clinical isolates for RPE culture was found to be at least as high as that for McCoy cell culture. At 24h PI, the percentage of inclusion-containing cells varied from 1.5 ± 0.52 to 14.6 ± 3.3% in hRPE cell culture infected at MOI of 2.0 against 0.37 ± 0.34 to 8.9 ± 0.2% in McCoy cell culture infected at MOI of 0.3. Collagen type I, collagen type IV, basic fibroblast growth factor, transforming growth factor-beta and interleukin–8 expression at 48h PI were maximally increased, by 2.1-, 1.3-, 1.5-, 1.5- and 1.6-fold, respectively, in the Chlamydia trachomatis-infected compared with control hRPE cell culture specimens (P < 0.05).ConclusionsThis study, for the first time, proved the possibility of infecting hRPE cultured cells with Chlamydia trachomatis, which leads to proproliferative and proinflammatory changes in the expression of signaling molecules and extracellular matrix components.
Conjunctival or intraocular inoculation with CT may result in invasion of the PS structures and durable persistence thereof, with the development of inflammatory and then degenerative changes. These data might advocate for expanding the role of chronic CT infection in etiology and pathogenesis of vitreoretinal disorders.
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