Isolation and Characterization of Novel Cocktail Phages of Multidrug-Resistant (MDR) Acinetobacter Baumannii

Abstract

Background: Acinetobacter baumannii is a nosocomial organism, classied as a critical pathogen with multidrug-resistant (MDR) challenges thus, it is urgently necessary to develop novel antimicrobial strategies. Phage therapy is an alternative and promising strategy, a highly effective biocontrol agent against MDR A. baumannii. This study characterizes three phages of MDR A. baumannii. Method: Acinetobacter baumannii was isolated from clinical wound specimens and was identied using VITEK® 2 system (Biomerieux, France). The antibiotic susceptibility prole was determined according to the Clinical and Laboratory Standard Institute (CLSI). Phages specic to MDR A. baumannii were isolated from sewage and irrigation channel samples, then tested for pH and temperature stability. Results: Among the A. baumanniistrains isolated, ve strains (Ab 140, Ab 150,Ab 333, Ab 1289, and Ab 976) showed remarkable resistance to antibiotics tested, with the resistance rate ranging from 90 to 40 %, respectively. Three lytic phages specic to Ab 140, Ab 150, and Ab 333 were isolated among ve MDR A. bamannnii isolates used for phage isolation. Lytic Phages specic to Ab 140 and Ab 150 produced clear big plaques with halo-like appearances around the inhibition zone, while Ab 333 produced clear and small size plaques. The phages were designated TJ 140, TJ 150, and TJ 333 and were stable in various pH and temperatures with a high survival rate in pH of 5.0 to 7.0 and 20 to 60 oC, respectively. Conclusion: The isolated phages exhibited strong lytic activity against MDR A. baumannii isolates tested and are stable in various pH and temperature ranges. They had no lytic eect on the heterogeneous strains and are good potential candidates for therapeutic applications.