The prevalence of blaTEM genes conferring ampicillin resistance (Ampr) in different soils was determined to clarify the environmental distribution of resistance determinants of major clinical importance. Samples were collected from 14 sites in New Zealand, mainland Norway, Svalbard, and 2 soil microcosms made of compost purchased in Italy. The Ampr bacteria represented 1.7-100% of the cultivable microflora with an average of 28%. Approximately 1200 Ampr isolates were further analyzed. Although >50% of the resistant isolates were capable ofβ-lactam-ring (nitrocefin) degradation, none carried a PCR-detectable blaTEM gene. The proportion of blaTEM genes in the culturable Ampr isolates was