انتاج انزيم البيتالاكتاميز من قبل بكتريا Klebsiella oxytoca

Abstract

Seventy three Klebsiella isolates were obtained from 200 urine sample taken from patients with urinary tract infection. Four of these isolates were identified as K. oxytoca. The sensitivity of bacteria to different antibiotics was tested ,all bacterial isolates were resistant to β-lactam antibiotics included Penicillin G, Benzathin Penicillin, Ampicillin, Amoxicillin, Piperacillin, Cephalothin, Amoxicillin - Clavulanic acid, Aztreonam, Cefotaxime, Cefixime, Ceftazidim, Tobramycin, Clindamycin, Cotrimoxazol, and Cephoxitin. All isolates were sensitive to Nitrofurantoin, Amikacin and Ticarcillin-Clavulanic acid whereas half of the isolates were sensitive to Nalidixic acid and the other half showed an intermediate sensitivity to it . The minimum inhibitory concentration had been determined for Penicillin G, Amoxicillin, Ampicillin, Piperacillin and Amoxicillin -Clavulanic acid it was 1024 microgram/ milliliter for all isolates. Whereas it was (32,16,4,2) microgram /milliliter for the isolates K38, K33, K44 and K27 respectively to Amikacin. It was (128,64,16 and 8) microgram/milliliter for the isolates K38, K33, K44 and K27 respectively to Nalidixic acid .The ability to produce betalactamase from these isolates was studied by the iodometric and acidimetric tests. All isolates produced the enzyme but K.oxytoca isolate K38 was the highly producer. The optimum conditions of betalactamase production from the selected isolate were the use of Brain Heartinfusion broth with 5% of bacterial inoculum at pH 7 for 4 hours of incubation at 37 Co in shaker incubator (125 rpm).