MOLECULAR AND MUTATION TRENDS ANALYSES OF OMP1 ALLELES FOR SEROVAR-E OF CHLAMYDIA-TRACHOMATIS - IMPLICATIONS FOR THE IMMUNOPATHOGENESIS OF DISEASE

Serovars E, F, and D are the most prevalent Chlamydia trachomatis stra ins worldwide. This prevalence may relate to epitopes that enhance inf ectivity and transmission. There are numerous major outer membrane pro tein (MOMP) gene (omp1) variants described for D and F but few for E. However, omp1 constant regions are rarely sequenced, yet, they may con tain mutations that affect the structure/function relationship of the protein. Further, differentiating variants that occur as a result of s election from variants that contain random mutations without biologic impact is difficult. We investigated 67 urogenital E serovars and foun d 11 (16%) variants which contained 16 (53%) nonconservative amino aci d changes. Using signature-pattern analysis, 57 amino acids throughout MOMP differentiated the E sequence set from the non-E sequence set, t hus defining E strains. Four E variants did not match this signature-p attern, and, by phenetic analyses, formed new phylogenetic branches, s uggesting that they may be biologically distinct variants. Our analyse s offer for the first time a unique approach for identifying variants that may occur from selection and may affect infectivity and transmiss ion. Understanding the mutation trends, phylogeny, and molecular epide miology of E variants is essential for designing public health control interventions and a vaccine.