title: Studies on the pathogenicity of thiamineless dwarf-colony variants of Staphylococcus aureus isolated from the bovine udder.
abstract: The pathogenic characteristics of thiamineless dwarf-colony variants of Staphylococcus aureus (D strains) were compared with those of normal S aureus isolated from the bovine udder. Intravenous injection of D strains into embryonated hen's eggs and intracranial inoculations into mice produced similar results to those with normal S aureus. Intramammary infusion of D strains into normal cows resulted in mastitis which was indistinguishable from the type produced by infusion of S aureus. Intramuscular injection of thiamine HCl into cows with chronic mastitis due to D strains did not alter the course of the disease, although normal sized S aureus colonies were isolated several days after thiamine injection.
mesh_terms: D000818:Animals; D002417:Cattle / Q000382:microbiology*; D002642:Chick Embryo; D005260:Female; D014644:Genetic Variation; D008321:Mammary Glands, Animal / Q000382:microbiology*; D008414:Mastitis, Bovine / Q000378:metabolism / Q000382:microbiology; D051379:Mice; D008892:Milk / Q000382:microbiology; D013203:Staphylococcal Infections / Q000378:metabolism / Q000382:microbiology / Q000662:veterinary; D013211:Staphylococcus aureus / Q000302:isolation & purification / Q000378:metabolism / Q000472:pathogenicity*; D013831:Thiamine / Q000378:metabolism; D014774:Virulence
chemical_list: D013831:Thiamine