Analysis of Susceptibility Patterns of Pseudomonas aeruginosa and Isolation, Characterization of Lytic Bacteriophages Targeting Multi Drug Resistant Pseudomonas aeruginosa

Abstract

Pseudomonas aeruginosa is known to be a major cause of Hospital Acquired Infections leading to high mortality in immune-compromised patients. Due to precipitous rise in antibiotic resistance, bacteriophages are significant alternative therapeutic approach for treatment and to combat resistance development. Objective of the current study was to identify MDR Pseudomonas aeruginosa from clinical isolates and to isolate bacteriophages from sewage samples against these MDR Pseudomonas aeruginosa strains. One hundred and forty-four Pseudomonas isolates were tested for their susceptibility pattern with 13 different antibiotics by micro-broth dilution method. Frequency of multidrug resistant (MDR) and Extensive Drug resistant (XDR) of Pseudomonas aeruginosa were found to be 35.5% and 23.6%, respectively. 7.61% isolates were identified as Pan drug resistant (PDR). Rate of susceptibility pattern were Piperacillin/Tazobactam 75%, Polymyxin B 74.6%, Meropenem 73.6%, Colistin 69.2%, Cefepime 54.9%, Ciprofloxacin 54.2%, Gentamicin 54.2%, Aztreonam 53.5%, Tobramycin 47.9%, Ticarcillin/Clavulanic acid 46.9%, Ertapenem 45.8%, Ceftazidime 40.3% and Imipenem 39.2%. Ninety-four bacteriophages were isolated from sewage samples against Pseudomonas aeruginosa PAO1/ATCC9027/clinical strains and host range testing study was carried out with all MDR clinical isolates. Among 51 MDR strains 34 strains were infected by phages. Phage infectivity rate were calculated for individual phages based on their host range infectivity results. AP025 and AP006 phages exhibited good infectivity rate of 39% and 30% respectively against MDR strains. Combination of 5 phages (AP002, AP006, AP011, AP025 and AP067) lysed 62.7% of the strains. Based on the obtained results, phages could be employed for treatment of infections caused by MDR strains with substantiated in-vivo experiments.