No abstract

No abstract

Although Citrobacter species in general were susceptible, antibiotic susceptibility testing is required for the detection of resistant isolates.

Background: New antibiotics are urgently needed for the treatment of multidrug resistant infections. However, the production of novel antibiotics is diminishing. The enhancement of activity of available antibiotics through synergistic combination drug therapy may help in the management of patients with resistant infections. Methods: Colistin-resistant Klebsiella pneumoniae isolates were collected from inpatients in 10 Greek hospitals and used in the study of combination activity of colistin plus azidothymidine. The combination activity was evaluated with the sum of fractional inhibitory concentrations (ΣFIC), using the mini checkerboard broth microdilution method. Results: 100 individual strains were tested. Synergistic activity was noted in 79% of the isolates (79/100) and additive activity in the rest 21% (21/100). ΣFIC 50 and ΣFIC 90 were 0.28 and 0.56, respectively. Conclusion: Colistin with azidothymidine exhibited promising synergistic activity against colistin-resistant carbapenem resistant Klebsiella pneumoniae isolates warranting further investigations of the combination.