Isolation and classification of the bacteriophages of Pseudomonas aeruginosa and their application on biofilm control / 中华微生物学和免疫学杂志

ABSTRACT

Objective To isolate and classigy the bacteriophages specific to Pseudomonas aetuginosa and to investigate biofilm control efficaey of the isolated virulent phages.Methods With P. aeruginosa clinical strains as indicators.bacteriophages were isolated by screening difierent environmental samples.Classification of the isolated phages was done with the methods of restriction fragment analysis of phage genome and host range analysis.Transmission electron microscopy(TEM)was used in phage morphology study.In biogilm control tests,TJC729 was used as the jndicator strain to study the biofilm control efficacy of the isolated phages.Results Total 13 lytic phages specific to P.aeruginosa strains were isolated and named as C1-C13.According to the result of restriction fragment analysis.all 13 phages were double-stranded DNA viruses and could be divided into eight groups.Host range experiments were conducted with 5 laboratory strains and 12 clinical strains of P. aeruginosa.The same infection profiles were observed among phage C1 and C13,C6 and C7,and C9 and C11,respectively.While the remaining 7 phages each had different unique infection profile.Phage C1 was selected randomly to study its morphology.The obtained images showed that phage C1 had an icosahedral head with a non-contractile tail,belonging to the Siphoviridae family.Compared with the single phage,phage cocktail had the best effect on biofilm control.Further experiment results showed that phage C1.C10 and C12 can destroy biofilm after treatment of the biofilm for 24 h.The biofilm amounts were deceased to 32.7%,57.6%and 32.8%of the initial values,respectively.Conclusion Thirteen virulent phages specific to P. aeruginosa had been isolated.The phages could significantly inhibit the biofilm formation and had a certain degree of damage on the biofilm.The results suggested an alternative method for the treatments of P.aeruginosa infections.