title: Activity of penicillin and novobiocin against bovine mastitis pathogens.
abstract: Penicillin (P), novobiocin (N), and both (P-N) were evaluated in vitro against 143 clinical isolates of bovine mastitis, including, Staphylococcus aureus, Streptococcus agalactiae, Streptococcus dysgalactiae, and Streptococcus uberis. Greater antistaphylococcal activities were demonstrated with N alone and P-N than with P alone. Streptococcus spp were more susceptible to P alone than to N alone, and the effectiveness of P-N corresponded with that of P alone. In vitro, P-N had a wider spectrum of antibacterial activity than did either P or N. Similar results were also obtained in vivo, using the mouse protection test. The P-N gave a greater protection rate in mice experimentally infected with S aureus and Str agalactiae than did P or N.
mesh_terms: D000818:Animals; D002417:Cattle; D005260:Female; D008414:Mastitis, Bovine / Q000382:microbiology*; D051379:Mice; D009675:Novobiocin / Q000494:pharmacology* / Q000627:therapeutic use; D010400:Penicillin G / Q000494:pharmacology* / Q000627:therapeutic use; D013203:Staphylococcal Infections / Q000188:drug therapy / Q000662:veterinary; D013210:Staphylococcus / Q000187:drug effects* / Q000302:isolation & purification; D013290:Streptococcal Infections / Q000188:drug therapy / Q000662:veterinary; D013291:Streptococcus / Q000187:drug effects* / Q000302:isolation & purification; D013292:Streptococcus agalactiae / Q000187:drug effects
chemical_list: D009675:Novobiocin; D010400:Penicillin G