Molecular and phylogenetic analysis of the F genotype of Chlamydia trachomatis isolated in Mexico in 2011

Background: Chlamydia trachomatis is the most frequently identified bacterium in sexually transmitted infections.Twenty C. trachomatis genotypes have been determined using the ompA gene and several genovariants by single nucleotide polymor-phism (SNP) analysis.In Mexico, the F genotype is the most frequent.Objective: To identify subtypes of the F genotype.Method: Seven C. trachomatis genotype F strains isolated in 2011 were analyzed by nucleotide sequencing and restriction enzyme mapping.Results: SNP analysis showed two strains with the same SNP at nucleotide 288 (C288T), while with res-triction enzymes, a variant with different RFLP (restriction fragment length polymorphism) was identified when treated with the mixture of HinfI and TaqI enzymes.Conclusion: In Mexico, there are two subtypes of F, and only with restriction enzymes HinfI and TaqI can one of the genovariants of the F genotype be identified.