tibacterial activity of eight antibiotics belonging to ve dif-ferent groups with Gram-positive multi-drug resistant clinical isolates. MATERIALS AND METHODS Micranisms Nine Gram-positive bacterial clinical isolat ve Staphylococcus aureu two Staphylococcus epide-rmidis and two Enterococcus faeciu were used in this study. They were human isolat nebivolol obtained from the University Hospit Alexandria Universi Egypt. They were identid by classical microscopic and biochemical procedur and tested for their susceptibility to dierent antibiotics by the antibiotic disc-diusion technique .
They were maintained at ° C as slant cultures of sterile nutrient agar for a maximum of month. Long-term preservation was performed by freezing in 5 glycerol broth. Drugs Recentin Drugs used in this study were obtained as pure pow-ders of pharmaceutical grade : the antihistamin azelastine and the antibiotics ampicilli cephradin cefotaxim cefepim cip-rooxaci doxycyclin erythromycin and gentamicin . Eect of azelastine on the antibacterial activity of antibiotics The eect of azelastine on the antibacterial activity of antibiotics was initially tested by determining the minimum inhibitory concentration of antibiot-ics in the presence and absence of 0 l g mL azelas-tine using the agar dilution technique .
The MIC of azelastine against the tested clinical isolates ranged between and l g mL . Abination was considered synergistic when the MIC of the antibiotic was reduced fourfold phenformin 834-28-6 or more in the presence of azelastine inparison with its absence. The eect of azelastine on the bactericidal activity of antibiotics was determined by the viable count technique. Antibiotics at al con-centration equivalent to one half the MIC value against each of the tested isolates were mixed individually with azelastine. They were added to bacterial suspensions of al inoculum for each of the tested isolates adjusted to cells mL in sterile saline solution at the zero ti then incubated at 7 ° C for 4 h. Proper controls lacking azelastine and or the antibiotic were included in each test. Sam-ples were aseptically withdrawn at , and 4 h. The number of survivors was determined by the surface viable count technique. The plates were incubated at 7 ° C for 4 h. Synergism was deed as log decrease in survivors with thebination in-parison with the most active single drug at any point. Moreov the dynamics of bactericidal activity of antibiotics in the presence or buy Danoprevir absence of 0 and l g mL azelastine were determined in nutrient broth Isolate MIC .
M minimum inhibitory concentration; a azelastine; a ampicillin cephradine cefotaxime; c cefepime; c ciprooxacin; d doxycycline; e erythromycin; g gentamicin. 6 ” The Authors APMIS ” APMIS without azelastine; with 0 l g mL azelastine. REVERSAL OF ANTIBIOTIC RESISTANCE BY AZELASTINE Ltd). The inoculum size used was cells mL. The systems were incubated at 7 ° C and 5 strokes min. Samples were aseptically withdrawn at and 4 h for the viable count determination. This test was also performed using dierent inoculum behavior sizes adjusted at , and cells mL and at four dierent pH values adjusted using the corresponding sterile phosphate buers and checked using pH meter.