HEMAGGLUTINATION BY PASTEURELLACEAE ISOLATED FROM RODENTS

Pasteurellaceae notably P. pneumotropica, have been associated with se vere outbreaks of respiratory disease in several species of rodents. H ost-specific parasitism of Pasteurellaceae in rodents has hardly been studied. Since host tropism in many bacteria involves adhesive mechani sms, we examined the hemagglutinating (HA) properties of 44 isolates f rom different rodent species (mouse (15) rat (8), hamster (9), gerbil (10) and Mastomys (2)). Only 13 mouse isolates and the 2 Mastomys isol ates hemagglutinated human (type O Rh+) and canine red blood cells (RB Cs). No HA was found using RBCs from 10 other animal species. HA was n ot inhibited by simple sugars and glycoconjugates, but was completely inhibited by heating of bacterial cells for 10 min at 80 or 100-degree s-C, partially inhibited by glutaraldehyde and inhibited in a dose-dep endent mode by NaIO4, suggesting the involvement of bacterial polysacc haride structures in the HA process. Enrichment procedures did not rev eal the presence of HA- subpopulations in HA+ isolates or the presence of HA+ subpopulations in HA- isolates. Electron microscopy revealed t he presence of fimbriae both in HA+ and HA- isolates. A regularly stru ctured (RS) layer was detected on cells of part of the HA+ isolates on ly. Our results suggest that Pasteurellaceae of mice and Mastomys may be related and differ from isolates isolated from other rodent species .