DISTRIBUTION OF THE RESIDENT ORAL BACTERIAL-POPULATIONS IN DIFFERENT STRAINS OF MICE

The distribution of the resident oral bacterial species was evaluated in six genetically different mouse strains (BALB/c, C3H/He, C57BL/6, C 57BL/10, DBA/2 and CD-1). The results indicate that these mouse strain s harbour different oral microbiota upon arrival at our animal facilit ies. However, this difference persists only in strains C57BL/10 and DB A/2 1 wk after arrival. Except for strains CD-1 and C57BL/10, the oral biota is different upon arrival compared to that observed after 1 wk at our animal facilities. For the same mouse strain, the oral biota ca n differ significantly from one shipment to another upon arrival but t ends to stabilise after 1 wk. This stabilising effect can be related t o the increase in the proportion of Lactobacillus murinus among the to tal cultivable oral microbiota. These results indicate that if the hos t genetic background influences the distribution of the oral bacterial populations, its effect is masked by environmental factors.