Identification of Chlamydia trachomatis genotypes in newborns with respiratory distress

INTRODUCTION

One hundred thirty million Chlamydia trachomatis infections are reported worldwide each year. Nineteen serotypes of this pathogen can cause infection in pregnant women and neonates. The distribution of these genotypes in newborns with respiratory infections in Mexico is unknown.

MATERIAL AND METHODS

We tested 1062 bronchial lavage samples from neonates with respiratory distress syndrome for Chlamydia infection. The diagnosis of Chlamydia was made by plasmid detection with an in-house PCR assay, and genotypes were identified using a PCR-RFLP assay for the ompA gene.

RESULTS

The genotyping of 40 strains identified 14 as I/Ia (35%), 13 as E (32.5%), 7 as D (17.5%), 5 as F (12.5%), and 1 as L2 (2.5%). The relative risk analysis showed that genotype D was associated with neonatal sepsis (RR, 5.83; 95% confidence interval [CI], 1.51-25.985; P < .02), while the I/Ia genotype was significantly associated with chorioamnionitis in the mother (2.8; 95% CI, 1.4-5.5; P < .05).

CONCLUSIONS

Although C. trachomatis genotypes I/Ia and E of were the strains involved most frequently in respiratory infections in Mexican neonates, 80% of patients with genotype F developed respiratory disease. In contrast, genotype D was associated with neonatal sepsis, and genotype I/Ia with chorioamnionitis.

Oral Chlamydia vaccination induces transmucosal protection in the airway

Although Chlamydia has been frequently detected in the gastrointestinal tracts of both humans and animals, it is not associated with any gastrointestinal pathology. We have recently shown that gastrointestinal Chlamydiamuridarum is not only non-pathogenic but also induces protective immunity in the genital tract. We now report that the transmucosal immunity induced by a single oral immunization with C.muridarum protected the mouse airway from a subsequent challenge infection. The oral immunization significantly reduced chlamydial burden in the airway as early as day 3 after intranasal challenge. As a result, the airway chlamydial spreading to extra-airway tissues was completely prevented on day 3 and significantly reduced on day 9. The immunized mice were protected from any significant systemic toxicity caused by the intranasal challenge since there was no significant bodyweight drop in the immunized mice. This robust protection correlated well with Chlamydia-specific antibodies that recognize chlamydial organism surface antigens and T cell responses that are dominated with a Th1 phenotype. The immunized mice developed high ratios of IgG2b/c over IgG1 levels and IFNγ-producing over IL-5- or IL-13-producing lymphocytes. Thus, we have demonstrated that oral vaccination with C. muridarum can induce Th1-dominant transmucosal immunity in the airway. Together with previous studies, we propose that non-pathogenic colonization of Chlamydia in the gastrointestinal tract be explored as an oral delivery system for inducing protection against infections and pathologies in extra-gastrointestinal tissues.

Seroprevalence of anti-Chlamydia trachomatis IgM in neonatal respiratory tract infections in Hungary

Purpose. To determine the seroprevalence of specific IgM indicative of respiratory tract infection (RTI) due to Chlamydia trachomatis (CT) among symptomatic infants.Methodology. A descriptive study was conducted on young infants up to 5 months old at the Bacterial Sexually Transmitted Infections Reference Laboratory, National Centre for Epidemiology, Budapest, covering the period 2008-2016. Serum samples from infants suffering from RTIs were screened with a micro-immunofluorescence test (Focus, Cypress, USA) for the presence of anti-Chlamydia trachomatis-specific IgM. A parallel Bordetella pertussis screening was performed by an indirect immunofluorescence test (Euroimmun, Lübeck, Germany) that detected specific IgM.Results.The CT-specific serum IgM was highly reactive in 50 (19.1 %) of the 262 neonates with RTIs, while all proved negative for Bordetella pertussis-specific IgM.Conclusion. Vertically transmitted C. trachomatis must be regarded as a common pathogen among symptomatic neonates with RTIs in Hungary. Routine screening and treatment of pregnant women could be one option to help prevent these conditions. Focused laboratory testing based on raised clinical awareness should enable early diagnosis and appropriate therapy for symptomatic infants.