Isolation of L-form variants after antibiotic treatment in Staphylococcus aureus bovine mastitis.
An unstable L-form of Staphylococcus aureus was identified in milk samples from 3 quarters of 2 cows after treatment with cloxacillin. Milk samples incubated on standard 5% blood agar plates were culture-negative for 7 to 30 days after treatment, but S aureus was reisolated in 80% of 66 samples by additional culturing on enriched L-form media when incubated in 10% CO2 at 37 C. The organism was identified at various phases of reversion of L-form agar and was confirmed on transfer to blood agar plates.
Sears
P M
PM
College of Veterinary Medicine, Mississippi State University, MS 39762.
Fettinger
M
M
Marsh-Salin
J
J
D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002417:Cattle; D002418:Cattle Diseases / Q000188:drug therapy / Q000382:microbiology; D003023:Cloxacillin / Q000494:pharmacology / Q000627:therapeutic use*; D003470:Culture Media; D005260:Female; D007740:L Forms / Q000187:drug effects / Q000302:isolation & purification*; D008414:Mastitis, Bovine / Q000188:drug therapy / Q000382:microbiology*; D008892:Milk / Q000382:microbiology; D013203:Staphylococcal Infections / Q000188:drug therapy / Q000382:microbiology / Q000662:veterinary*; D013211:Staphylococcus aureus / Q000187:drug effects / Q000302:isolation & purification*
D000900:Anti-Bacterial Agents; D003470:Culture Media; D003023:Cloxacillin