RESUMO
Uptake of [3H]dihydrostreptomycin in sensitive and resistant strains of cowpea rhizobia was examined to explain one of the possible mechanisms of intrinsic antibiotic resistance. The rate of acummulation of labelled streptomycin in resistant strains was drastically reduced when compared to that of sensitive strains. Our results indicated that high levels of intrinsic antibiotic resistance was due to decreased permeability causing failure to accumulate the drug. However, the causes for high levels of intrinsic resistance of rhizobia to any of the antibiotics are not known. One of the mechanisms of durg resistance in the lab isolates of enteric bacteria is decreased permeability resulting in failure to accumulate the drug. In this work, we investigated the uptake of labelled streptomycin in sensitive and resistant strains of cowpea rhizobia isolated in Jamaica and West Africa and showed that the high level of intrinsic resistance was due to the cell's inability to take up the drug (AU)
