Insight into behavior of epithelial cells of the feline conjunctiva in chronic conjunctivitis as a possible limitation in detection of Chlamydophila spp.

The aims of this work was documentation of the reactivity of feline conjunctival epithelial cells in chronic conjunctivitis and the investigation of a possible correlation of histological findings in conjunctiva with a limitation in detection of the pathogen. In this observational study, conjunctival swab samples collected from six cats suffering from chronic conjunctivitis were monitored for Chlamydophila spp. infection for one month, every ten days. Chlamydophilosis was diagnosed by conventional PCR, and confirmed by sequencing analysis. A lack of coherence with results in subsequent studies using PCR did not allow an accurate diagnosis. Additional bioptat samples of conjunctiva were collected for diagnostic purposes and stained in haematoxylin and eosin following the Giemsa method for light microscopic analysis. Additionally the samples were incubated for 15 min with IMAGEN Chlamydia conjugate (IMAGEN Chlamydia reagent kit, Dako, UK), allowing immunofluorescence detection of Chlamydophila spp. Within the epithelium an increased number of goblet cells, as well as general enlargement of the epithelium and a reduced number of normal epithelial cells, was observed. Only in areas of low epithelium could structures similar to the elementary bodies of Chlamydophila spp. be distinguished. The presented data document a possible limitation in molecular evidence for chlamydophila infection in some naturally infected cats, taking into account histological conditions in conjunctiva at the same time.