Distribution of armA gene and aminoglycoside resistance in gramnegative bacteria from different sources

Abstract:

ObjectiveTo investigate the distribution of 16S rRNA methylase armA and its relationship with drug resistance of gramnegative bacteria from different sources.Methods953 strains of gramnegative bacteria from different sources were analyzed by conventional antimicrobial susceptibility testing, armA gene was detected by quantitative fluorescence polymerase chain reaction, relationship between carrying of armA gene and aminoglycoside susceptibility was analyzed.ResultsA total of 846 clinical gramnegative bacteria and 107 zoonotic Klebsiella spp. strains were collected, resistance rates of Acinetobacter spp. to amikacin and gentamicin were 86.4%(152/176) and 89.8%(158/176) respectively. Carrying rate of armA gene in Acinetobacter spp. was up to 66.5%. Resistance rates of 107 zoonotic Acinetobacter spp. strains to amikacin and gentamicin, as well as carrying rate of armA gene were all higher than clinical Klebsiella spp. strains, which were 74.8%, 79.4%, and 65.4% respectively. Resistance rates of 256 armAcarrying strains to amikacin and gentamicin were 95.7% and 98.4% respectively.ConclusionDifferent species of gramnegative bacteria had different aminoglycoside susceptibility and with different carrying rates of armA gene, but they all show high consistence between carrying of armA gene and aminoglycoside resistance phenotype, which suggest that the detection results of armA in gramnegative bacteria can predict the susceptibility of strains to aminoglycosides.