Study of the Effect of Bacteriophages on Biofilm Formation of Pseudomonas Aeruginosa

Abstract

Introduction: Pseudomonas aeruginosa is an opportunistic pathogen to humans and causes nosocomial infections. Positive for catalase and oxidase test and can grow well at 37-42°C, non-fermenting, non-spore-forming, rod-shaped, and gram-negative
aerobic. It has virulence factors that contribute to the success of infection and cause disease. Biofilm is one of the most important virulence factors for these bacteria. Bacteriophages have been used to act as anti-biofilm agents. This study aim to study the effect of bacteriophage on biofilm formation of Pseudomonas aeruginosa.
Methods: 100 samples were collected, including 50 wounds and 50 burns samples from Baquba General Hospital in Diyala Governorate. Bacteriological identification was used to identify P. aeruginosa isolates. The bacteria's Antibiotics susceptibility test was performed by the Kirby Banner method and on Mueller-Hinton medium. A biofilm formation test was conducted by microtiter plate quantitative method (MTP), to determine the ability of bacteria to biofilms formation. Bacteriophages were isolated from the sewage of Baquba Hospital before treatment. Finally, a test was conducted to inhibit the formation of biofilms using bacteriophages and the ELISA method.
Result: The results showed that 10 bacterial isolates were isolated from 100 samples. A lower percentage of antibiotic resistance against Piperacillin/Tazobactam was 12% and Imipenem was 14% and a higher resistance percentage was seen against ceftriaxone was 90%. While the resistance percentage for Gentamycin was 32.4%, Amikacin was 32%, Ceftazidime was 60%, Ciprofloxacin was 30%, and Aztreonam was 37.2%. The biofilm formation results showed that 8 (80%) of the isolates produced biofilm. Four bacteriophages were used so that we could eliminate a larger number of bacteria. The results of biofilm inhibition using bacteriophages were 20 % for the first and second bacteriophages and 40% for the third bacteriophage, while for the fourth bacteriophage, the inhibition rate was 60%.
Conclusions: Bacteria showed the ability to biofilms formation and also the effective effect of bacteriophages to inhibit biofilm formation.