Transconjugants were selected by transferring the 2-3 loopfuls of the suspension onto over-dried Mueller-Hinton agar
plates containing nalidixic acid (40 mg/L) with either tetracycline (40 mg/L) as hydrochloride, streptomycin (40 mg/L), trimethoprim (10 mg/L), or chloramphenicol (40 mg/L).
The dried surface of a Mueller-Hinton agar
plate is inoculated by streaking the swab over the entire sterile agar surface.
The MIC of oxacillin was determined by an agar dilution method in accordance with NCCLS recommendations  on Mueller-Hinton agar
containing 4% NaCl (Fluka, Spain) and oxacillin at concentrations ranging from 0.
The case definition of a probable KPC isolate stated that ESBL bacteria have an MIC [greater than or equal to]1 [micro]g/mL to imipenem by broth dilution, confirmed by the Modified Hodge Test (a disk-diffusion procedure, using meropenem or ertapenen discs on Mueller-Hinton agar
to detect carbapenemase production).
90]) of the isolates was determined on Mueller-Hinton agar
2] and even on Mueller-Hinton agar
with added blood may be necessary.
Osaka, Japan); Mueller-Hinton Agar
(Difco Laboratories, Detroit, MI, USA).
Antimicrobial drug susceptibility tests were conducted by using Mueller-Hinton agar
and the disk diffusion method.
Minimum inhibitory concentration (MIC) was performed for ciprofloxacin and chloramphenicol by agar dilution technique using Mueller-Hinton agar
(MHA) (Hi-media, Mumbai) according to the criteria of CLSI (9).
The susceptibility testing against antibiotics was carried out on Mueller-Hinton agar
plates (BBL, Cockeysville, USA) according to the procedures described by Bauer et al.
MRSA can be screened with the NCCLS approved method that uses 6 [micro]g/mL of oxacillin in Mueller-Hinton agar
supplemented with 4% sodium chloride.
Coproduction of ESBL was confirmed by adding 200 mg/L cloxacillin (Sigma-Aldrich, Munich, Germany) to Mueller-Hinton agar
(Oxoid) using disks (Oxoid) according to CLSI ESBL confirmatory tests with disks of cefotaxime and ceftazidime, with or without clavulanic acid.