title: Mechanisms of gentamicin resistance in gram-negative bacilli in Riyadh, Kingdom of Saudi Arabia.
abstract: A survey was undertaken of the prevalence and mechanisms of gentamicin resistance in Gram-negative bacilli in Riyadh. Gentamicin resistance, as assessed by the Stokes method, occurred in less than 2% of isolates of Escherichia coli, about 10-25% of most other enterobacteria, about 40% of Acinetobacter spp. and about 25% of Pseudomonas aeruginosa. This finding of relatively low rates of gentamicin in Enterobacteriaceae was surprising in view of the unregulated use of antibiotics until recent years. AAD(2'') was by far the most commonly detected aminoglycoside-modifying enzyme in the enterobacteria. However Providencia spp. always produced AAC(2') and there was an association between Serratia spp and AAC(6'). Enzymes were less frequently detected in Acinetobacter spp. and Pseudomonas spp. AAD(2'') was also the most common enzyme in Pseudomonas spp. but was never found in Acinetobacter spp. Non-enzymatic resistance played an insignificant role in the resistance of Enterobacteriaceae in Riyadh, but may be more important in Pseudomonas spp.
authors.affiliation: Department of Microbiology, U.M.D.S., St. Thomas' Campus, London, UK.
authors.forename: A
authors.initials: A
authors.lastname: Moaz
authors.forename: K
authors.initials: K
authors.lastname: Shannon
authors.forename: I
authors.initials: I
authors.lastname: Phillips
mesh_terms: D001424:Bacterial Infections / Q000382:microbiology; D004352:Drug Resistance, Microbial; D004755:Enterobacteriaceae / Q000187:drug effects / Q000201:enzymology; D005839:Gentamicins / Q000494:pharmacology*; D006090:Gram-Negative Bacteria / Q000187:drug effects* / Q000201:enzymology; D006801:Humans; D008826:Microbial Sensitivity Tests; D012529:Saudi Arabia
chemical_list: D005839:Gentamicins