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.

Identificación de genotipos de Chlamydia trachomatis en neonatos con distrés respiratorio / Identification of Chlamydia trachomatis genotypes in newborns with respiratory distress

Introducción: Cada año se notifican ciento treinta millones de infecciones por Chlamydia trachomatis en todo el mundo. Diecinueve serotipos de este patógeno pueden causar infecciones en mujeres embarazadas y recién nacidos. En México se desconoce la distribución de estos genotipos en recién nacidos con infecciones respiratorias. Material y métodos: Se analizaron mil sesenta y dos muestras de lavado bronquial de neonatos con síndrome de dificultad respiratoria para detección de infección por clamidia. El diagnóstico de clamidia se realizó mediante la detección de plásmidos con un ensayo PCR interno y los genotipos se identificaron mediante un ensayo PCR-RFLP del gen ompA. Resultados: El genotipado de 40 cepas identificó a 14 como I/Ia (35%), 13 como E (32,5%), 7 como D (17,5%), 5 como F (12,5%) y 1 como L2 (2,5%). El análisis de riesgo relativo mostró que el genotipo D se asoció con sepsis neonatal (RR=5,83; IC 95%: 1,51-25,985; p <0,02), mientras que el genotipo I/Ia mostró asociación significativa con madres que desarrollaron corioamnionitis (2,8; IC 95%: 1,4-5,5; p <0,05). Conclusiones: Si bien los genotipos I/Ia y E de Chlamydia trachomatis fueron la causa más frecuente de infección respiratoria en neonatos mexicanos, el 80% de los genotipos F produjeron este padecimiento. En cambio, el genotipo D se asoció con el desarrollo de sepsis neonatal y el genotipo I/Ia con corioamnionitis. (AU)

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 Chlamydia 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. (AU)