Chlamydia trachomaatis DNA in leukocytes of peripheral blood from neonates

Introduction: Diagnosis of Chlamydia trachomatis infection in newborns is difficult; however, this diagnosis is performed by cell culture or by detection of IgM antibodies against C trachomatis. Detection of C trachomatis DNA in peripheral blood leukocytes using polymer chain reaction (PCR) may be a better tool for the diagnosis of infection by this pathogen. Material and methods: A total of 44 premature newborns, all weighing less than 2500 g, were included in the study. A blood sample and nasopharyngeal lavages were obtained from each newborn. Leukocyte DNA was obtained by phenol-chloroform extraction technique. Detection of C trachomatis was performed by amplifying the ompA gene using the PCR endpoint. Cell culture tests and the detection of IgM antibodies against C trachomatis by microimmunofluorescence assay were also performed. Results: Twenty newborns were PCR-positive (45.5%), with this test being significantly associated with the presence of pneumonia (RR=2.28; 95% CI: 1.01 to 5.17; P=.035). The cell culture of nasopharyngeal lavage was positive in only 7 samples and no significant association was observed with any clinical or laboratory data. The titer of IgM antibodies against C. trachomatis associated with PCR-positive was 1:32 (RR=2.74; 95% Cl: 1.21 to 6.23; P=.008), however this titer was not associated with the presence of pneumonia. Conclusion: DNA detection in peripheral blood leukocytes could be useful for diagnosis of C trachomatis infection. (C) 2014 Elsevier Espana, S.L.U. and Sociedad Espanola de Enfermedades Infecciosas y Microbiologia Clinica. All rights reserved.