Susceptibility of Gramnegative Carbapenemase-Producing Bacteria to Various Group Antibiotics

The study involved 25 Isolates of gramnegative carbapenemase-producing bacteria. 17 isolates of Klebsiella pneumonia produced carbapenemase NDM-1 and were highly resistant to cephalosporins (MIC>128 mcg/ml), carbapenems (MIC>16 mcg/ml), aminoglycosides and fluoroquinolones, while among them 4 isolates preserved susceptibility to azthreonam and all of them were susceptible to tigecycline and polymyxin. 2 isolates of Acinetobacter genomospecies 13 produced NDM-1 and were resistant to all the beta-lactams and amikacin, while preserved susceptibility to gentamicin, co-trimoxazole, tigecycline and polymyxin, the susceptibility to ciprofloxacin being lowered. Carbapenemase VIM-4 was produced by 2 isolates of Enterobacter cloacae, which were highly resistant to cephalosporins and azthreonam, significant synergism being observed between cefepim and clavulanate. The resistance of the isolates to carbapenems was low (MIC 0.5-4.0 mcg/ml), they also being resistant to aminoglycosides and ciprofloxacin and susceptible to tigecycline and polymyxin. Carbapenemases KPC-2 were detected in 2 isolates of K.pneumoniae and in 1 isolate of E.cloacae. The above isolates were resistant to all the beta-lactams, ciprofloxacin, aminoglycosides and co-trimoxazole. 1 isolate of E.cloacae showed resistance to tigecycline and 1 isolate of K.pneumoniae was resistant to polymyxin. Carbapenemase OXA-48 was detected in 1 isolate of K.pneumoniae. It was resistant to all the beta-lactams, ciprofloxacin and co-trimoxazole and susceptible to aminoglycosides, tigecycline and polymyxin.

carbapenemases, producers, gramnegative bacteria, antibioticograms

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