CHARACTERIZATION OF AVIAN CHLAMYDIA-PSITTACI STRAINS USING OMP1 RESTRICTION MAPPING AND SEROVAR-SPECIFIC MONOCLONAL-ANTIBODIES

In the present study, 60 avian Chlamydia psittaci isolates were charac terized using restriction fragment length polymorphism as well as sero var-specific monoclonal antibodies, enabling a comparison between the two characterization methods. Sixty avian C. psittaci isolates were ch aracterized by AluI restriction mapping of the major outer membrane pr otein gene omp1 obtained after amplification by the polymerase chain r eaction. The 60 avian C. psittaci strains were also characterized usin g serovar-specific monoclonal antibodies in a microimmunofluorescence test. Digestion of 60 avian C. psittaci omp1 amplicons by AluI generat ed 5 of the 6 known distinct restriction patterns (A, B, D, E and F). Restriction pattern C was not observed. Serotyping revealed 4 avian C. psittaci serovars (A, B, C and D). None of the 60 isolates was typed as serovar E. AluI restriction patterns A, B, D and E corresponded in 98% of the cases to serovars A, B, C and D, respectively. One isolate, classified as serovar A, generated restriction pattern F instead of A . Genotyping enabled a more precise differentiation of avian C. psitta ci serovar A strains. Serovar A strains were divided into two groups a ccording to their AluI restriction pattern (A or F). For epidemiologic al studies, genotyping can thus be a highly valuable alternative to se rotyping, especially when applied directly to the clinical samples.