5 research outputs found
Real-time PCR methods for quantitative monitoring of streptomycin and tetracycline resistance genes in agricultural ecosystems
Antibiotic application in plant agriculture is primarily used to control fire blight caused by Erwinia amylovora
in pome fruit orchards. In order to facilitate environmental impact assessment for antibiotic applications, we
developed and validated culture-independent quantitative real-time PCR multiplex assays for streptomycin
(strA, strB, aadA and insertion sequence IS1133) and tetracycline (tetB, tetM and tetW) resistance elements in
plant and soil samples. The qPCR were reproducible and consistent whether the DNA was extracted directly
from bacteria, plant and soil samples inoculated with bacteria or soil samples prior to and after manure slurry
treatment. The genes most frequently identified in soils pre- and post-slurry treatment were strB, aadA, tetB
and tetM. All genes tested were detected in soils pre-slurry treatment, and a decrease in relative
concentrations of tetB and the streptomycin resistance genes was observed in samples taken post-slurry
treatment. These multiplex qPCR assays offer a cost-effective, reliable method for simultaneous quantification
of antibiotic resistance genes in complex, environmental sample matrices