Detection and Differentiation of Chlamydiae by Nested PCR

Chlamydiae are obligate intracellular prokaryotes with a hexalaminar cell wall that, in contrast to other gram-negative bacteria, contains no peptidoglycan. As a major antigenic constitutent, their outer membrane contains a 10-kDa lipopolysaccharide (LPS) with a trisaccharide epitope specific for the family Chlamydiaceae (1 ). Another characteristic antigenic component is the major outer membrane protein (MOMP), a cysteine-rich protein of approx 40 kDa representing approx 60% of the weight of the outer membrane. This molecule harbors several genus- and species-specific antigenic determinants in the conserved regions and serovar-specific epitopes in variable domains (2 ).