Aminoglycoside-Inactivating Enzymes in Clinical Isolates of Streptococcus Faecalis

摘要: Abstract Clinical isolates of enterococci (Streptococcus faecalis) with high-level resistance to both streptomycin and kanamycin (minimal inhibitory concentration >2,000 μg/ml), resistant synergism penicillin or were examined for aminoglycoside-inactivating enzymes. All the 10 strains studied had adenylyltransferase neomycin phosphotransferase activities; latter enzyme phosphorylated amikacin as well its normal substrates, such kanamycin. Substrate profiles activity suggested that phosphorylation occurred at 3′-hydroxyl position, i.e., aminoglycoside 3′-phosphotransferase. A transconjugant strain, which acquired antibiotic after mating a clinical isolate, also activities. Quantitative in vitro by sonicate strain inactivated antibiotic, measured bioassay, drug failed produce when combined against sensitive penicillin-amikacin synergism. No differences found sensitivity ribosomes from using polyuridylic acid directed [14C]-phenylalanine incorporation presence streptomycin, kanamycin, amikacin. Therefore, we conclude enzymes are responsible resistance, observed these strains.