Chlamydia trachomatis immunotype J.

A new immunotype J is proposed for a group of Chlamydia trachomatis strains which are related to trachoma type C in the microimmunofluorescence typing test. Ten immunologically identical strains have been identified from four separate areas of the world. The strains were either isolated from the genital tract or from eye infection originating from the genital tract. They grow readily in HeLa 229 cell culture but poorly in egg culture. Whereas two-way cross-reactions were found between types C and J, tests with mouse antisera cross-absorbed with heterologous antigens showed that type J is completely separable from type C. The J strain caused typical follicular conjunctivitis in monkey eyes. Both humans and monkeys infected with J strains developed type-specific micro IF antibody patterns similar to immunized mouse antisera. C antisera showed broader and higher titer heterologous reactions than J antisera. Two immunologically identical strains, UW-61/Cx and 469/OC, related to both C and J, remain unclassified. They immunologically bridge the two types but are more closely related to type C immunologically and at the same time resemble type J epidemiologically and biologically.