Colonisation of the upper respiratory tract of mice with group B streptococci type III with reference to the R-protein.
Nine strains of group B streptococci type III, five with R-protein (R+) and four without (R-) were tested for capacity to colonise the upper respiratory tract in mice and to adhere to human buccal cells. In the mouse model, 80-microliter inocula of dilutions of overnight cultures of the strains in Todd Hewitt broth were placed in the external nares under light ether anaesthesia. A pilot experiment demonstrated that it was reasonable to study the throat colonisation 2 and 4 days after inoculation. Groups of 18-20 mice were then given inocula containing 8 X 10(6) cfu/ml of five R+ and four R- strains. At day 4, significantly more mice were colonised with type III, R+ strains (73% of the animals) than with type III, R- strains (44%) (p less than 0.01). In adherence experiments with human buccal cells, no difference was found between the R+ and R- strains. The results indicated that the higher colonisation rate among R+ strains was mediated by mechanisms other than adherence.
D000268:Adhesiveness; D000818:Animals; D001426:Bacterial Proteins / Q000502:physiology*; D002610:Cheek; D005260:Female; D006801:Humans; D051379:Mice; D009061:Mouth Mucosa / Q000382:microbiology; D010614:Pharynx / Q000382:microbiology*; D013292:Streptococcus agalactiae / Q000145:classification / Q000254:growth & development* / Q000502:physiology
D001426:Bacterial Proteins