OBJECTIVES We evaluated the genetic and molecular basis of high-level resistance to gentamicin and amikacin in 91 clinical isolates of Enterococcus faecalis and Enterococcus faecium in a university hospital in southern Italy from 1987 to 2003. METHODS Antibiotic susceptibility was evaluated by disc diffusion and microdilution methods. Genotyping was performed by PFGE and dendrogram analysis. ...

A gentamicin-resistant mutant of Pseudomonas aeruginosa PAO503 was selected after ethyl methane sulfonate mutagenesis. The strain, P. aeruginosa PAO2401 had increased resistance to all aminoglycosides tested but exhibited no change for other antibiotics. The mutation designated aglA (aminoglycoside resistance) was 50% cotransducible with the 8-min ilvB,C marker on the P. aeruginosa chromosome. ...

background and objective: high-level gentamicin resistance (hlgr: mic ≥ 500 µg/ml) in enterococci is mediated by aminoglycoside modifying enzymes which is mainly encoded by aac(6′)-ie-aph(2′′)-ia gene. the aim of this study was to evaluate the frequency of   aac(6′)-ie-aph(2′′)-ia gene in clinical isolates of enterococcus facium and enterococcus faecalis collected from hospitals in northwest of...

OBJECTIVES To understand the molecular epidemiology of gentamicin-resistant Campylobacter and investigate aminoglycoside resistance mechanisms. METHODS One-hundred-and-fifty-one gentamicin-resistant Campylobacter isolates from humans (n = 38 Campylobacter jejuni; n = 41, Campylobacter coli) and retail chickens (n = 72 C. coli), were screened for the presence of gentamicin resistance genes by ...

Enterococcal endocarditis is usually treated with a combination of a penicillin and an aminoglycoside. Recent reports have documented the emergence of enterococci in France with high-level resistance to gentamicin, tobramycin, and kanamycin and the emergence of strains in Houston, Tex. with high-level resistance to all of these drugs and streptomycin. In this study, we examined strains from a g...

Antibiotic resistance of heterotrophic bacteria isolated from the surface microlayer and subsurface water of downtown pond was determined. The levels of resistance of bacteria to various antibiotics differed considerably. It follows from the results that bacteria were most resistant to penicillin and sensitive to gentamycin, neomycin and oxytetracycline. Majority of bacterial strains were chara...

During a 14-month period beginning in July 1986, three distinct clinical isolates of Streptococcus (Enterococcus) faecium demonstrating high-level resistance (MIC, greater than 2,000 micrograms/ml) to gentamicin, kanamycin, tobramycin, and streptomycin were recovered from individual patients at one institution. Combinations of ampicillin with any of these agents failed to show bactericidal syne...

Enterococcus faecalis LC40 is an ampicillin-susceptible clinical isolate with high-level gentamicin resistance due to the aac(6')-Ie-aph(2")-Ia aminoglycoside resistance gene. The combination of ampicillin plus arbekacin reduced mean bacterial vegetation counts significantly more than ampicillin alone or ampicillin plus gentamicin in a rabbit model of aortic-valve endocarditis caused by E. faec...

BACKGROUND AND AIMS Enterococci are among resistant microorganisms to antibiotics and are responsible for some of acute gingival infections. This study aimed at molecular evaluation of gentamicin-resistant enterococcus species and determining the resistance genes. MATERIALS AND METHODS Clinical samples were cultured on BHI medium and enterococci were isolated by specific methods and antibiogr...