Gentamycin

This was done using the disc diffusion technique on freshly prepared Mueller Hinton Agar. The test antibiotics used in the study were Ciprofloxacin (30 μg), Streptomycin (30 μg), Septrin (15 μg), Gentamycin (15 μg), Amoxicillin (30 μg), Ceftriazone (10 μg), Ciprofloxacin (30 μg), Pefloxacin (10 μg), Gentamycin (30 μg) and Augmentin (10 μg) (Becton Dickinson, USA). The diameters of the zones of inhibition were interpreted as resistance and susceptible according to the NCCLS guideline [38 ].

Antimicrobial susceptibility was assessed by the disk diffusion method according to Clinical and Laboratory Standards Institute (CLSI) guidelines [8 9 ]. For 34 E. faecalis and 32 E. faecium isolates, 14 antibiotics were used to test susceptibility: ampicillin (AM), 10 µg; amoxicillin-clavulanic acid (AMC), 30 µg; chloramphenicol (C), 30 µg; tetracycline (TE), 30 µg; ciprofloxacin (CIP), 5 µg; erythromycin (E), 15 µg; imipenem (IPM), 10 µg; sulfamethoxazole/trimethoprim (SXT), 23.75 µg/1.25 µg; gentamycin (GM), 10 µg; streptomycin (S), 10 µg; high-level gentamicin (HLGM), 120 µg; high-level streptomycin (HLS), 300 µg; kanamycin (K), 30 µg; and quinupristin/dalfopristin (SYN), 15 µg (BD Biosciences). Each cultured single isolate was suspended in 0.85% NaCl and turbidity was adjusted to 0.5 McFarland. Five antibiotic disks were placed on each Mueller-Hinton agar (BD Biosciences) plate followed by incubation at 37℃ for 24 h. The diameters of the inhibitory zone of the disks were measured and tested isolates were determined to be susceptible, intermediate, or resistant based on the CLSI M100-S24 E. faecalis and E. faecium breakpoint guidelines. Interpretive criteria were adapted from Enterobacteriaceae guidelines as published in CLSI M100-S23 when the breakpoint was unavailable. S. aureus ATCC 25923 and E. faecalis ATCC 29212 were used as controls.

Yeasts were grown aerobically at 37°C on Sabouraud agar with 0.4 g/l chloramphenicol and 0.04 g/l gentamycin (BD Diagnostics, Franklin Lakes, NJ, USA). All in vitro investigations were conducted on a third subculture of C. albicans ATCC 10231 (Oxoid; Thermo Fisher Scientific, Inc., Waltham, MA, USA) suspended in Sabouraud broth (cat. no. CM147; Oxoid™; Thermo Fisher Scientific, Inc.) or in distilled water. The suspension was adjusted to 1–20×106 blastoconidia per ml by dilution, following a blastoconidia count using a Thoma cell counting chamber (Marienfeld™, Lauda-Königshofen, Germany). Wild strains were isolated by swabbing from dentures and identified on the basis of their colony aspect on CHROMagar™ medium (BD Diagnostics), by chlamydoconidia formation on BT™ Rice Extract agar (BD Diagnostics) and by the API yeast identification system (bioMérieux, Marcy-l'Etoile, France).