title: In vitro susceptibilities of field isolates of Mycoplasma agalactiae to oxytetracycline, tylosin, enrofloxacin, spiramycin and lincomycin-spectinomycin.
abstract: The minimum inhibitory concentrations (MICs) of tetracycline, enrofloxacin, tylosin, spiramycin and a lincomycin:spectinomycin 1:2 combination, against 24 Sicilian isolates of Mycoplasma agalactiae, the causative organism of contagious agalactia were determined in vitro by a broth dilution method. Enrofloxacin was the most effective antimicrobial in vitro with a range of MIC values from 0.125 to 0.500 microg/ml and an MIC(50) of 0.203 and MIC(90) of 0.365 microg/ml. Using the MIC(50) and MIC(90) values the remaining four antimicrobials are ranked in order of in vitro effectiveness as follows: tylosin (MIC(50)0.292; MIC(90)0.525 microg/ml) was slightly more effective than tetracycline (MIC(50)0.296; MIC(90)0.533 microg/ml), followed by lincomycin:spectinomycin (MIC(50)0.521; MIC(90)0.938 microg/ml) and spiramycin (MIC(50)1.583; MIC(90)2.850 microg/ml). MIC values above 1.000 microg/ml were obtained using tetracycline, tylosin and spiramycin for some M. agalactiae isolates.
authors.affiliation: Institute Zooprofilattico, Sperimentale della Sicilia, Via Rocco Dicillo, 4 I-90129, Palermo, Sicily, Italy.
authors.forename: G R
authors.initials: GR
authors.lastname: Loria
authors.forename: C
authors.initials: C
authors.lastname: Sammartino
authors.forename: R A J
authors.initials: RA
authors.lastname: Nicholas
authors.forename: R D
authors.initials: RD
authors.lastname: Ayling
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D000890:Anti-Infective Agents / Q000494:pharmacology; D000077422:Enrofloxacin; D005260:Female; D024841:Fluoroquinolones; D008034:Lincomycin / Q000494:pharmacology; D008826:Microbial Sensitivity Tests; D009174:Mycoplasma / Q000187:drug effects* / Q000302:isolation & purification; D009175:Mycoplasma Infections / Q000188:drug therapy / Q000382:microbiology / Q000662:veterinary*; D010118:Oxytetracycline / Q000494:pharmacology; D015363:Quinolones / Q000494:pharmacology; D012756:Sheep; D012757:Sheep Diseases / Q000188:drug therapy / Q000382:microbiology*; D012802:Sicily; D000198:Spectinomycin / Q000494:pharmacology; D015572:Spiramycin / Q000494:pharmacology; D015645:Tylosin / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D000890:Anti-Infective Agents; D024841:Fluoroquinolones; D015363:Quinolones; D000077422:Enrofloxacin; D015572:Spiramycin; D000198:Spectinomycin; D008034:Lincomycin; D010118:Oxytetracycline; D015645:Tylosin