Slime production by coagulase-negative staphylococci isolated in chronic blepharitis

Background. The purpose of the study was to determine the impact of slime-p roducing strains of coagulase-negative staphylococci (CNS) on non-ulcerativ e blepharitis. Formerly considered harmless organisms, CNS are now recognis ed as opportunistic pathogens. Although these microorganisms are a componen t of normal conjunctival flora, they often produce the typical signs and sy mptoms of chronic staphylococcal blepharoconjunctivitis. Certain strains pr oduce a polysaccharide extracellular material called "slime". Slime product ion is considered to be associated with the virulence of the organism. Methods. Swabs were taken from the lids of 38 eyes of 19 patients with chro nic non-ulcerative blepharitis and cultured for CNS. A group of 42 normal c ontrol eyes were similarly sampled. The strains of CNS isolated from 26 eye s (68.4%) of the patients with blepharitis and 25 eyes (59.5%) of the norma l subjects were studied for slime layer production. Results. No significant difference was found between normal subjects and pa tients in the incidence of slime producing CNS strains from the conjunctiva . The antibiotic sensitivity profiles of the slime-producing strains were n o different from the slime-negative isolates in the blepharitis (p=0.85) an d normal group (p=0.25). Conclusions. Our data suggest that slime production by CNS does not play a significant role in the pathogenesis of staphylococcal blepharitis.