The elements conferring high-level gentamicin resistance in 64 clinical isolates of Enterococcus faecalis were characterized by PCR and by restriction enzyme hybridization analysis of genomic and plasmid DNA. There was a strong association between gentamicin resistance and the aac(6')-aph(2") gene carried on IS256-based elements with different structures, locations, and transfer characteristics.

Fecal samples from 200 consecutive patients admitted to a community hospital yielded 107 enterococci. High-level gentamicin resistance occurred in 10 (14%) of the Enterococcus faecalis isolates. Ampicillin resistance occurred in two (3%) of the E. faecalis isolates and six (23%) of the Enterococcus faecium isolates. There were no vancomycin-resistant enterococci. Risk factors for enterococci wi...

We have compared the rates of infection and resistance in an animal model of an orthopaedic procedure which was contaminated with a low-dose inoculum of Staphylococcus epidermidis. We randomised 44 Sprague-Dawley rats to have bone cement implanted subcutaneously containing either gentamicin or saline (control). The wound was inoculated with a dilute solution of gentamicin-sensitive Staphylococc...

Vancomycin monotherapy of deep-seated staphylococcal infection may be associated with poor bacteriological response. We evaluated 24 unique patient isolates of methicillin-resistant Staphylococcus aureus (MRSA) for vancomycin-gentamicin synergism by determining time-kill curves for vancomycin at 10 micrograms/ml and gentamicin at 1 microgram/ml. Nine MRSA strains showed high-level gentamicin re...

BACKGROUND Anti-microbial lock solutions (AML), in conjunction with systemic antibiotics, may successfully treat tunnelled haemodialysis catheter-related bloodstream infections (CR-BSI). It is unknown whether AML promote anti-microbial resistance. METHODS This is a retrospective cohort study of all CR-BSI (2003-2006) in our dialysis unit. Controls (n = 265) were treated with systemic vancomyc...

High-level resistance to gentamicin was studied in seven clinical isolates of Enterococcus hirae. In common with other members of the genus Enterococcus, such resistance in E. hirae was associated with single, large, conjugative plasmids. Molecular genetic analysis revealed five distinct plasmid types amongst the seven isolates. The determinant mediating high-level gentamicin resistance in E. h...

The in vivo activities of cefsulodin, sulbenicillin, and gentamicin were compared in mice infected intraperitoneally with Pseudomonas aeruginosa. In mice infected with sulbenicillin- and gentamicin-susceptible strains, cefsulodin was about 12 to 60 times more active than sulbenicillin and had an activity similar to gentamicin. In mice, the activity of cefsulodin was independent whether the stra...

Enterococci may display high level resistance to aminoglycosides, in which case synergy with cell-wall active antibiotics will be lost. All enterococcal blood culture isolates at Royal Brisbane Hospital have been screened by agar dilution for high level resistance to gentamicin and streptomycin since 1989. Of 110 isolates of Enterococcus faecalis, 16% displayed high level resistance to gentamic...

We isolated 11 nonconjugative plasmids mediating resistance to aminoglycoside antibiotics, including gentamicin, from Pseudomonas aeruginosa strains. Their genetic properties were investigated in both P. aeruginosa and Escherichia coli transformants. The plasmid molecular weights ranged from 11 x 10(6) to 24 x 10(6). A low level or complete absence of gentamicin resistance was observed when the...