Related Experiment Videos
Determinants of trachoma endemicity using Chlamydia trachomatis ompA DNA sequencing
Y H Hsieh1, L D Bobo, T C Quinn
1Division of Infectious Diseases, Department of Medicine, Johns Hopkins University, 720 Rutland Avenue, Baltimore, Maryland 21205, USA. yhhsieh@jhmi.edu
Microbes and Infection
|May 30, 2001
Summary
This study in Tanzania found that Chlamydia trachomatis ompA gene variations and host factors contribute to severe trachoma. Understanding these determinants is key to controlling this blinding eye disease.
Area of Science:
- Ophthalmology
- Microbiology
- Genetics
Background:
- Trachoma remains a leading cause of preventable blindness globally.
- Identifying factors driving trachoma endemicity is crucial for effective control strategies.
Purpose of the Study:
- To investigate the determinants of trachoma endemicity in Tanzanian children.
- To analyze Chlamydia trachomatis ompA genotypes and their association with ocular disease severity.
Main Methods:
- A six-year prospective study involving 749 conjunctival samples from Tanzanian village children.
- Sequencing of the Chlamydia trachomatis ompA gene (variable domains 1-4).
- PCR-enzyme immunoassay for infection detection and genotyping.
Main Results:
- High ompA gene polymorphism was observed, with 26 genotypes of serovar A and 19 of B/Ba identified.
- B/Ba genotypes showed increased nucleotide substitution in VD2, linked to age and water availability.
- Homotypic infection, multiple genotype infections, and high chlamydial load predicted severe trachoma.
Conclusions:
- High ompA gene variability and host inability to clear infections contribute to severe trachoma.
- Multitypic infections were associated with village residence and cattle ownership.
- These findings highlight distinct but converging mechanisms driving endemic severe trachoma.