Determinants of trachoma endemicity using Chlamydia trachomatis ompA DNA sequencing.
Microbes Infect
; 3(6): 447-58, 2001 May.
Article
en En
| MEDLINE
| ID: mdl-11377206
A six-year prospective study of Chlamydia trachomatis infection and ocular disease in Tanzanian village children was conducted to identify the determinants of trachoma endemicity using sequencing of ompA. Overall, 749 conjunctival samples were obtained, with 176 children sampled in both 1989 and 1995. 31.1% (233/749) were positive by PCR-enzyme immunoassay, and 76% (176/233) of the positives were sequenced in variable domains (VD) 1 to 4 (22 children in both 1989 and 1995). Twenty-six ompA genotypes of serovar A, and 19 of B/Ba were identified, and only 20% of genotypes identified in 1995 matched those found in 1989. In particular, B/Ba genotypes exhibited a 15-base region in VD 2 with increased nucleotide substitution, and these types were associated with age and water availability. Homotypic infection and infection with multiple genotypes and high chlamydial load did predict subsequent severe trachoma (odds ratio (OR) = 10.14, 95% confidence interval (CI): 1.71, 60.23; OR = 6.40, 95% CI: 0.75, 54.41; OR = 6.74, 95% CI: 0.82, 55.38, respectively). And, multitypic infection was clustered with residence of village and associated with familial cattle ownership. In conclusion, high ompA polymorphism and the inability of some hosts to clear infection with the same ompA genotype suggest two distinct but converging mechanisms of endemic severe trachoma.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Polimorfismo Genético
/
Proteínas de la Membrana Bacteriana Externa
/
Chlamydia trachomatis
/
Tracoma
Tipo de estudio:
Observational_studies
/
Prognostic_studies
/
Risk_factors_studies
Límite:
Animals
/
Child
/
Child, preschool
/
Humans
País/Región como asunto:
Africa
Idioma:
En
Revista:
Microbes Infect
Asunto de la revista:
ALERGIA E IMUNOLOGIA
/
MICROBIOLOGIA
Año:
2001
Tipo del documento:
Article
País de afiliación:
Estados Unidos
Pais de publicación:
Francia