IN-VITRO ATTACHMENT AND INVASION OF CHICKEN OVARIAN GRANULOSA-CELLS BY SALMONELLA-ENTERITIDIS PHAGE TYPE-8

The attachment and invasion of chicken ovarian granulosa cells by Salm onella enteritidis was examined in vitro. The attachment was inhibited by preincubation of granulosa cells with anti-chicken fibronectin ant ibody (approximately 70% reduction in attachment) or preincubation wit h a 14-kDa fimbrial protein isolated from S. enteritidis (68% reductio n in attachment). Treatment of bacterial cells with the tetrapeptide R GDS before addition to granulosa cells resulted in inhibition of attac hment (60% inhibition when 2 x 10(7) CFU of bacteria was treated with 500 mu g of peptide). Treatment with the peptide GRGD resulted in simi lar magnitude of inhibition, indicating that extracellular matrix prot eins play significant roles in the interaction of S. enteritidis with granulosa cells. In contrast, treatment of the bacterial cells with th e peptide GRAD did not result in significant inhibition of attachment to the granulosa cells. S. enteritidis was found to attach specificall y to fibronectin, collagen IV, and laminin-coated microtiter plate wel ls, with the rank order of attachment as follows: fibronectin > lamini n > collagen N. Light and transmission electron micrographs of S. ente ritidis invasion of granulosa cells showed organisms with or without a surrounding membrane in the cytoplasm of granulosa cells. In some ins tances, dividing bacterial cells were observed in the cytoplasm. Resul ts of this study demonstrated that S. enteritidis interacts with granu losa cells in a specific manner and can invade and multiply in these c ells. The granulosa cell layer of the preovulatory follicles may be a preferred site for the colonization of the chicken ovaries by invasive strains of S. enteritidis.