European Journal of Biomedical and Pharmaceutical Sciences

EFFECT OF LOW DOSE OF GAMMA RADIATION ON MULTIDRUG RESISTANT GRAM- NEGATIVE BACTERIA ISOLATED FROM BURN AND WOUND INFECTIONS

Zahraa A. Khadam and Mohammed F. AL-Marjani*

ABSTRACT

The effect of gamma irradiation on the growth and multi drug resistance of Gram- negative bacteria isolated from burn and wound Infections were studied. These isolates included 23 isolates of Pseudomonas aeruginosa, 17 isolates of Klebsiella pneumonia and 10 isolates of Acinetobacterbaumannii. The susceptibility to different antimicrobial agents was evaluated and the production of extended spectrum beta lactamases (ESβLs) and metallo beta lactamases(MβLs) were studied. All isolates were multi-drug resistant, and the resistance was 100% to tetracycline while all isolates were sensitive to colistin. The results also showed that (43.47%),(26.08%) of P.aeruginosa had ability to produce ESβLs and MβLs respectively, (50%), (71.42% ) of K.pneumoniae isolates had ability to produce ESβLs and MβLs respectively, while none of A.baumanniihad ability to produce these enzymes. PCR wasused to amplify the blaTEM; blaCTX; blaIMP and blaVIM genes that encoded to produce ESβLsandMβLs. Results were revealed that percentage of blaTEM(90%), (90%) and (70%) in P.aeruginosa, K.pneumoniae and A.baumanniiisolates, the presence of blaIMP in (40%) of P.aeruginosaandK.pneumoniae isolates (for each ) ,and (50%) of A. baumannii isolates. The results of irradiation bacterial isolates showed that Cesium (137CS 5μci) and Sodium (22Na) were effected against P. aeruginosa isolates, which reduces the CFUs (95.38%) and (95.07%) respectively. Sodium (22Na) was effective source against A.baumannii which reduced the growth (75.75%). The resistance of these isolatesto the tested antibiotics were not changed after exposure to gamma irradiation, except in case of ciprofloxacin against P.aeruginosa and ciprofloxacin, amoxicillin-clavulanic acid, cefepime, ceftazidime and cefoxitin against K. pneumoniae. Also, their ability to produce ESβLs and MβLs were not changed.

Keywords: Gram- negative bacteria, multi drug resistance, ES?Ls, M?Ls, gamma rays.