Effect of a novel podophage AB7-IBB2 on Acinetobacter baumannii biofilm

Biofilm formation in Acinetobacter baumannii is a common cause of nosocomial infections in humans. Clinical devices and abiotic surfaces are important sites of colonization leading to formation of biofilms. Such infections are often resistant to multiple antibiotic therapies, and hence there is need for an effective mode of control. Herein, we describe the isolation, characterization of a new lytic bacteriophage of A. baumannii and its effect on biofilm. The phage AB7-IBB2, with a genome size of about 170 kb was identified to be of family Podoviridae as revealed by transmission electron microscopy. It had an isometric head (35 nm) and a short tail (7 nm). It lysed 19/39 (49 %) clinical isolates of A. baumannii. Rapid adsorption (>99 % adsorbed in 4 min), a latency period of 25 min and a burst size 22 PFU/infected cell was observed. The phage could inhibit A. baumannii biofilm formation and disrupt preformed biofilm as well. The phage has promising potential to be considered as a candidate biocontrol agent for A. baumannii infections.