RESUMEN
Waddlia chondrophila and Chlamydia trachomatis are intracellular bacteria associated with human miscarriage. We investigated their role in human preterm birth. Whereas presence of Chlamydia trachomatis DNA in genital tract was associated with human preterm birth, Waddlia was not, despite being present in women's genital tracts.
RESUMEN
Waddlia chondrophila is considered as an emerging human pathogen likely involved in miscarriage and lower respiratory tract infections. Given the low sensitivity of cell culture to recover such an obligate intracellular bacteria, molecular-based diagnostic approaches are warranted. We thus developed a real-time PCR that amplifies Waddlia chondrophila DNA. Specific primers and probe were selected to target the 16S rRNA gene. The PCR specifically amplified W. chondrophila but did not amplify other related-bacteria such as Parachlamydia acanthamoebae, Simkania negevensis and Chlamydia pneumoniae. The PCR exhibited a good intra-run and inter-run reproducibility and a sensitivity of less than ten copies of the positive control. This real-time PCR was then applied to 32 nasopharyngeal aspirates taken from children with bronchiolitis not due to respiratory syncytial virus (RSV). Three samples revealed to be Waddlia positive, suggesting a possible role of this Chlamydia-related bacteria in this setting.
Asunto(s)
Técnicas Bacteriológicas/métodos , Chlamydiales/aislamiento & purificación , Infecciones por Bacterias Gramnegativas/diagnóstico , Reacción en Cadena de la Polimerasa/métodos , Niño , Chlamydiales/genética , Cartilla de ADN/genética , ADN Bacteriano/genética , ADN Ribosómico/genética , Femenino , Infecciones por Bacterias Gramnegativas/microbiología , Humanos , Lactante , Recién Nacido , Nasofaringe/microbiología , ARN Ribosómico 16S/genética , Reproducibilidad de los Resultados , Sensibilidad y EspecificidadRESUMEN
During the last 15 years, several new bacterial species related to Chlamydia have been discovered within amoebae. Their ability to grow within these professionnal phagocytes suggests that they are also resistant to destruction by other phagocytic cells such as alveolar macrophages and that they may be excellent candidates as new agents of pneumonia. There are growing evidence that these Chlamydia-like organisms play a role as etiological agent of lower respiratory tract infections. Thus, Parachlamydia is apparently an agent of inhalation pneumonia and--at least in the immunocompromised host--of community-acquired pneumonia, whereas Simkania is considered as a common agent of bronchiolitis and an emerging agent of pneumonia. Nevertheless, their pathogenic potential remains underestimated since these obligate intracellular bacteria grow only poorly or not at all on the culture media generally used to detect pathogen in diagnostic laboratories.