OBJECTIVES: To determine the in vitro activities and interactions of imipenem, colistin and tigecycline with old antibacterial agents against carbapenem-resistant Acinetobacter baumannii. METHODS: Forty-three carbapenem-resistant A. baumannii isolates from the intensive care unit of a university hospital were collected and their MICs of imipenem, colistin and tigecycline were determined. With eight randomly selected carbapenem-resistant isolates, an in vitro time-kill study was performed for the evaluation of antibacterial activity of colistin, tigecycline, imipenem/sulbactam and colistin/rifampicin. RESULTS: The time-kill study of colistin demonstrated bactericidal activity against A. baumannii at concentrations of 4xMIC and 8xMIC, whereas tigecycline showed bacteriostatic activity at all concentrations. The combination regimens of imipenem/sulbactam and colistin/rifampicin were synergistic and bactericidal at 1xMIC. CONCLUSIONS: Imipenem/sulbactam combination, colistin and tigecycline showed good in vitro activities against carbapenem-resistant A. baumannii isolates. Even though colistin is bactericidal against carbapenem-resistant A. baumannii, the colistin/rifampicin combination is more warranted in order to be certain.
OBJECTIVES: To determine the in vitro activities and interactions of imipenem, colistin and tigecycline with old antibacterial agents against carbapenem-resistant Acinetobacter baumannii. METHODS: Forty-three carbapenem-resistant A. baumannii isolates from the intensive care unit of a university hospital were collected and their MICs of imipenem, colistin and tigecycline were determined. With eight randomly selected carbapenem-resistant isolates, an in vitro time-kill study was performed for the evaluation of antibacterial activity of colistin, tigecycline, imipenem/sulbactam and colistin/rifampicin. RESULTS: The time-kill study of colistin demonstrated bactericidal activity against A. baumannii at concentrations of 4xMIC and 8xMIC, whereas tigecycline showed bacteriostatic activity at all concentrations. The combination regimens of imipenem/sulbactam and colistin/rifampicin were synergistic and bactericidal at 1xMIC. CONCLUSIONS:Imipenem/sulbactam combination, colistin and tigecycline showed good in vitro activities against carbapenem-resistant A. baumannii isolates. Even though colistin is bactericidal against carbapenem-resistant A. baumannii, the colistin/rifampicin combination is more warranted in order to be certain.
Authors: José Garnacho-Montero; George Dimopoulos; Garyphallia Poulakou; Murat Akova; José Miguel Cisneros; Jan De Waele; Nicola Petrosillo; Harald Seifert; Jean François Timsit; Jordi Vila; Jean-Ralph Zahar; Matteo Bassetti Journal: Intensive Care Med Date: 2015-10-05 Impact factor: 17.440
Authors: Louise M Oleksiuk; M Hong Nguyen; Ellen G Press; Cassaundra L Updike; Jessica A O'Hara; Yohei Doi; Cornelius J Clancy; Ryan K Shields Journal: Antimicrob Agents Chemother Date: 2013-11-18 Impact factor: 5.191
Authors: Ryan K Shields; Cornelius J Clancy; Louise M Gillis; Eun J Kwak; Fernanda P Silveira; Rima C Abdel Massih; Gregory A Eschenauer; Brian A Potoski; M Hong Nguyen Journal: PLoS One Date: 2012-12-20 Impact factor: 3.240