Isolation, characterization and antibiofilm efficacy of a novel Klebsiella pneumoniae phage

The multidrug-resistant (MDR) Klebsiella pneumoniae is an important pathogen that threatens public health directly with life-threatening infections. The need for the development of new effective and well tolerated alternative treatments for these infections is crucial. Therefore, the interest in phage therapy as a promising alternative is increasing. Here, a novel phage named Phi AYH was isolated from the Tigris River water, Baghdad, IRAQ near sewage of Baghdad Medical City with its specific host from the same site. Phage Phi AYH belongs to Podoviridae family in the order Caudovirales. The Phi AYH maintained stability at different temperatures (-10 to 60 degrees C) and pH values (5-11). The phage was able to lyse 8 from 32 clinical K. pneumoniae isolates in vitro with no lytic activity against other tested species. For one-step growth, latent period was 10 min with burst size similar to 64 virions/cell at multiplicity of infection (MOI) 10. The SDS-PAGE test revealed one major structural protein and different structural proteins ranging from 28 to 89 kDa in size. The phage host and 32 clinical K. pneumoniae isolates were tested for phenotypic identification and antibiotics profile by VITEK-2 system and genotypically using rpob gene. All clinical K. pneumoniae isolates showed resistance to the most antibiotics tested while phage host was resistant only to amoxicillin. Biofilm production by all clinical isolates including the host isolate was tested. These isolates showed different ability as following: 72.72% as weak, 6.06% as moderate, and 21.21% as strong biofilm producer. Together these results demonstrate that Phi AYH is a promising alternative against MDR K. pneumoniae.