J. Valle

In vitro susceptibility of Escherichia coli strains isolated from diarrhoeic lambs and goat kids to 14 antimicrobial agents.

The in vitro activities of 14 anti‐microbial agents were determined against 92 strains of E. coli isolated from lambs (60 strains) and kids (32 strains) affected by neonatal diarrhoea. The overall percentage of resistant strains to streptomycin, sulphadimethoxine and tetracycline was very high (above 70%). A high level of resistance (from 30% to 50%) to ampicillin, kanamycin, neomycin and chloramphenicol was also detected. The E. coli strains were highly susceptible to cephalosporins, polymyxin and quinolones. Most of the strains showed multiresistance: 77.2% of isolates were resistant to at least two antibiotics, 55.4% were resistant to at least four antibiotics and 33.7% were resistant to at least six antibiotics. A total of 34 antibiotypes could be distinguished.

Aetiology of ovine footrot in Spain

Four hundred and sixty strains of obligate anaerobes were isolated from 216 cases of ovine footrot distributed throughout Spain. The predominant species was Dichelobacter nodosus, which was isolated in 168 cases (77.8 per cent). A higher proportion of the strains of D nodosus than of the other strains had elastolytic activity, 118 of the 168 strains degrading elastin. Species belonging to the genus Prevotella were isolated from 96 cases (44.4 per cent). Serotyping of the D nodosus strains showed that serovars Al, A2 and C were the most commonly isolated in Spain.

In vitro activities of enoxacin, enrofloxacin, sparfloxacin, and ciprofloxacin against Escherichia coli strains isolated from diarrheic lambs and kids.

The in vitro activities of four fluoroquinolone compounds were tested against 92 Escherichia coli strains of ovine and caprine origin under aerobic and anaerobic incubation conditions. The four fluoroquinolones proved to be highly effective against the E. coli isolates tested. When bacteria were cultured anaerobically, at least fourfold increases in the MICs of enoxacin for the strains occurred and no detectable changes in enrofloxacin, sparfloxacin, and ciprofloxacin MICs occurred.

Efficacy of the E‐test in evaluating the antimicrobial susceptibility of anaerobic bacteria of veterinary interest

A study was made of the sensitivity of 39 clinical isolates of anaerobic bacteria to 10 antimicrobial agents. Minimal inhibitory concentrations (MICs) were calculated using a new method—the E‐test (AB Biodisk, Solna, Sweden)—and compared with those obtained using the conventional agar dilution method. Agreement between the MICs obtained by the two methods with a variation of ± 2 dilutions was 78.7%. The E‐test, though less sensitive than the conventional agar dilution method, may be of value in clinical veterinary practice when rapid selection of treatment for a given infectious process is required.

Production of elastase in staphylococci isolated from goats

A study was made of elastase production in 273 staphylococcal strains isolated from healthy goats by two different methods. In a soluble elastin medium, 20.2% of the strains tested showed elastolytic activity but no strains showed such activity in an insoluble elastic medium.