Abstract

In this study, the lytic phage for multidrug-resistant (MDR) Pseudomonas aeruginosa was isolated; this phage belongs to the Myoviridae and Siphoviridae. Analysis of its genome sequences highlighted by different antibiotic resistance gene primers offered the most direct and sensitive method of determining the therapeutic status of this lytic phage. Interestingly, this approach reveals the existence of vanAcassette in the genome of this lytic phage. Whereas van B gene primers highlighted the polymerase chain reaction (PCR) product of 1248 bp, which has shown a relation with ABC transport proteins ofEnterococcus faecalis V583 instead of the ligase meant for the van B resistance trait. BLASTn analysis of the sequenced product has shown the existence of small stretches on Pseudomonas phage PCR product. These predicted signature sequences of phage PCR product are 100% identical with signature sequences of the same size but located at different sites on the genome of E. faecalis V583 corresponding to ABC transporter proteins. Six signature sequences were identified. These signatures are different from Walker A and human ABC signatures. Presumably, these signatures reflected the relation with Walker B sequence. Our data suggested that Pseudomonas lytic phage has some proteins that have partial homologous structure to ABC-transporter with Walker B motifs. The existence of these unique signature sequences once in different ABC transporter in E. faecalis V583 and phage genome has reflected the presence of some functional domains on these proteins that have not yet been identified, and their function need to be elucidated.

Key words: Bacteriophage, lytic phage, van B, ABC-transporters, Walker B signature.