Antimicrobial resistance among Pseudomonas spp. and the Bacillus cereus group isolated from Danish agricultural soil

From four Danish pig farms, bacteria of Pseudomonas spp. and the Bacillus c ereus group were isolated from soil and susceptibility towards selected ant imicrobials was tested. From each farm, soil samples representing soil just before and after spread of animal waste and undisturbed agricultural soil, when possible, were collected. Soil from a well-characterized Danish farm soil (Hojbakkegaard) was collected for comparison. The Psudomonas spp. and B. cereus were chosen as representative for Gram-negative and Gram-positive indigenous soil bacteria to test the effect of spread of animal waste on s election of resistance among soil bacteria. No variations in resistance lev els were observed between farms; but when the four differently treated soil s were compared, resistance was seen for carbadox, chloramphenicol, nalidix an (nalidixic acid), nitrofurantoin, streptomycin and tetracycline for Pseu domonas spp., and for bacitracin, erythromycin, penicillin and streptomycin for the B. cereus group. Variations in resistance levels were observed whe n soil before and after spread of animal waste was compared, indicating an effect from spread of animal waste. (C) 2001 Elsevier Science Ltd. All righ ts reserved.