Pathogenicity of Staphylococcus aureus phage type 3A/3C/55/71 and Staphylococcus sciuri in germfree euthymic and athymic mice after intravenous infection

Abstract

To evaluate the possibility ofprotecting our colonies of small laboratory animals against Staphylococcus aureus infections by preassociation with the rodent specific Staphylococcus sciuri, it was first of all necessary to determine the pathogenicity of the S. sciuri strain under consideration. Germfree euthymic Han: NMRI and athymic (T-cell deficient) Han:NMRInu/nu mice were injected intravenously with increasing doses of S. sciuri strain 908/1. S. aureus (phage type 3A/3C/55/71) which is known to cause health problems in SPF colonies of the above mentioned strains of mice was used for comparison.
S. aureus infections exhibited a dosedependent morbidity and mortality in both strains of mice. In contrast, S. sciuri did not cause any lethal infection but produced sporadically mild purulent processes in the euthymic mice. Due to the use of relatively small groups a statistical evaluation can only show tendenc1es.