ABSTRACT
Genus-, subspecies-, and serotype 1-specific antigens of Chlamydia psittaci were characterized by immunoblot analysis, using monoclonal antibodies that recognize 2 C psittaci strains: AB7 isolated from an ewe that had aborted, and iB1 isolated from feces of a healthy ewe. Genus-specific epitopes were detected on lipopolysaccharide, on a 47-kd protein, and on a 27- to 30-kd doublet. Subspecies-specific epitopes were located on a 30-kd protein, and a 80- to 90-kd protein region was identified, which bore subspecies- and serotype 1-specific epitopes. These 80- to 90-kd proteins were highly reactive with serum from ewes that had aborted and could be a useful antigen for diagnosis of chlamydial induced abortion of ruminants.
Subject(s)
Abortion, Veterinary/diagnosis , Bacterial Proteins/immunology , Chlamydia Infections/veterinary , Chlamydophila psittaci/immunology , Epitopes/analysis , Sheep Diseases/diagnosis , Abortion, Veterinary/microbiology , Animals , Antibodies, Monoclonal , Chlamydia Infections/complications , Chlamydia Infections/diagnosis , Chlamydophila psittaci/classification , Female , Mice , Mice, Inbred BALB C , Pregnancy , Serotyping , Sheep , Sheep Diseases/microbiology , Species SpecificityABSTRACT
Specific antigens of virulent strains of Chlamydia psittaci isolated from ruminants were characterized by western blotting. The immunoblot analyses were performed with chlamydial elementary bodies from abortive (AB7 strain) or intestinal (iB1 strain) chlamydiae using mouse and rabbit immune sera raised against viable chlamydiae or proteic extracts. Eleven antigens were found to be AB7-specific, but only 4 (96, 90, 88 and 49-50 kDa) were recognized by both mouse and rabbit sera against viable AB7 strains. These could be candidates for specific diagnosis of caprine and ovine abortive chlamydiosis. No iB1-specific antigen recognized by mouse and rabbit anti-sera could be identified.
Subject(s)
Antigens, Bacterial/analysis , Chlamydophila psittaci/immunology , Psittacosis/veterinary , Sheep Diseases/microbiology , Animals , Blotting, Western , Chlamydophila psittaci/pathogenicity , Cross Reactions , Female , Goat Diseases/diagnosis , Goats , Mice , Psittacosis/diagnosis , Psittacosis/microbiology , Rabbits , Sheep , Sheep Diseases/diagnosis , VirulenceABSTRACT
Protein patterns displayed in sodium dodecyl sulphate (SDS) electrophoresis by invasive and noninvasive strains of Chlamydia psittaci showed three constant differences, the most distinctive being a band at 90 Kd from invasive strains. In comparison with other methods so far described, this method provides a more efficient means of differentiating between invasive and non-invasive strains. Furthermore, it may lead to the development of improved methods of diagnosis.
Subject(s)
Bacterial Proteins/analysis , Chlamydophila psittaci/analysis , Animals , Chlamydophila psittaci/isolation & purification , Chlamydophila psittaci/pathogenicity , Electrophoresis, Polyacrylamide Gel , Molecular Weight , Peptides/analysis , Sheep/microbiologyABSTRACT
The pathogenicity of chlamydial strains for their natural hosts and their ability to induce persistent infections in McCoy cells were compared. Both virulent and avirulent strains persistently infected McCoy cells, but the appearance of the cell culture varied between strains. Avirulent strains induced completely inapparent persistent infection (infection Type 1), while with invasive strains the culture alternated between periods of cell multiplication and periods of extensive cytopathic change (infection Type 2). The virulence of virulent strains was not attenuated, even after 6 months of culture, but after 2 or 3 months some avirulent strains produced infection Type 2 and became invasive for mice and abortive for ewes. This variation of virulence was accompanied by a modification of protein patterns.
