Agar fitting Gram-negative rods in the subgingival flora of dogs

The phenotypic characteristics as well as the prevalence and quantity (colo ny forming units/ml/sample) of 39 bacterial isolates of agar pitting Gram-n egative rods, from two diseased and one healthy subgingival site from each of 16 pet dogs with naturally occurring periodontitis, were investigated. P henotypic features were determined with use of standard biochemical methods , by enzymatic profiling with the API ZYM system, and by cellular fatty aci d profiling. The organisms detected were motile, catalase-negative Campylob acter sp., present in 69% of the dogs and in 29% of the subgingival samples (69/29), motile, catalase-positive Campylobacter sp. (63/29), Eikenella co rrodens (25/10), organisms closely resembling E. corrodens but nitrate-nega tive and unable to grow in air, designated E. corrodens-like (19/8), Biloph ila wadsworthia (6/2), and non-motile Campylobacter sp. (6/2). The most fre quent organisms were the motile Campylobacter isolates constituting 72% of all isolates. No statistically significant differences were detected betwee n the diseased and healthy subgingival sites, with regard to the prevalence of any of these groups of organisms. Furthermore, the bacterial isolates w ere detected in almost equal numbers in the diseased and healthy sample sit es. Hence, no association between dog periodontitis and the agar pitting Gr am-negative rods was established. The phenotypic data also suggest, that th e organisms that were only presumptively identified in the present study (C ampylobacter sp., E. corrodens-like), may not have been previously describe d. (C) 2000 Academic Press.