5-epi-Sisomicin and 5-epi-Gentamicin B: substrates for aminoglycoside-modifying enzymes that retain activity against aminoglycoside-resistant bacteria

5-epi-Sisomicin and 5-epi-Gentamicin B: substrates for aminoglycoside-modifying enzymes that retain activity against aminoglycoside-resistant bacteria.

A number of bacterial strains, each possessing a different aminoglycoside-modifying enzyme, were examined for susceptibility to sisomicin and gentamicin B and the semisynthetic derivatives 5-epi-sisomicin and 5-epi-gentamicin B. Although strains possessing AAC (6') or APH(3') enzymes were equally resistant to the 5-epi-compounds, those possessing AAC(3)-I, ANT(2"), or AAC(2') enzymes were much ...

Aminoglycoside cross-resistance patterns of gentamicin-resistant bacteria.

Ten strains each of Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa were habituated to gentamicin by serial passage in antibiotic containing medium. Complete cross-resistance to streptomycin, neomycin, kanamycin, and tobramycin in a linear proportional fashion was demonstrated at all stages of habituation. Most strains of Staph. aureus and Ps. aeruginosa showed a greater inc...

Modifying enzymes related aminoglycoside: analyses of resistant Acinetobacter isolates.

Enzymatic modification of aminoglycosides by nucleotidyltransferases, acetyltransferases and/or phosphotransferases accounts for the majority of aminoglycoside-resistant Acinetobacter isolates. In this study, we investigated the relationship between aminoglycoside resistance and the presence of aminoglycoside-modifying enzymes in Acinetobacter baumannii clinical isolate groups with different re...

Synthesis of 3"-epi-dihydrostreptomycin active against resistant bacteria.

Microplate phosphocellulose binding assay for aminoglycoside-modifying enzymes.

We modified the phosphocellulose binding assay for aminoglycoside-modifying enzymes (AMEs) by use of microdilution plates and a multichannel micropipette. Batteries of aminoglycoside substrates for screening organisms for the presence of AMEs as well as for subclassifying enzymes were prepared and stored in microdilution plates. When tested in parallel with the conventional tube reaction assay,...