In VitroSusceptibility ofEscherichia coliStrains Isolated from Diarrhoeic Dairy Calves to 15 Antimicrobial Agents

• DOI: 10.1046/j.1439-0450.2000.00356.x
• Publication Date: 2003-03-12T09:13:13Z
• Authors: J. A. Orden; J. A. Ruiz‐Santa‐...; S. Garcia; D. Cid; R. De La Fuente
• Keywords: Kanamycin; Florfenicol; Spectinomycin; Tylosin; Neomycin; Polymyxin; Carbenicillin

Summary The in vitro activities of 15 antimicrobial agents against 195 strains Escherichia coli isolated from dairy calves affected by neonatal diarrhoea were determined. Of these 137 produced one or more potential virulence factors (F5, F41, F17, cytotoxic necrotizing factor, verotoxin and the eae gene), but remaining 58 did not produce any factors. overall percentage resistant to streptomycin, tylosin tetracycline was very high (above 65 %). A level resistance (from 23 50 %) ampicillin, neomycin, kanamycin, spectinomycin, chloramphenicol, sulphadimethoxine trimethoprim also detected. E. susceptible (89–95 apramycin gentamicin highly (99–100 polymyxin B, florfenicol nitrofurazone. Some significant differences ( P >0.05) frequencies some antimicrobials tested rates multi‐drug among producing non‐fimbriated, non‐toxigenic, ‐negative found. Most showed multi‐resistance: 76.9 >% isolates at least two antibiotics, 67.7 % four antibiotics 50.3 six antibiotics.