The correlation between biofilm formation capability and antibiotic resistance pattern in Pseudomonas aeruginosa

Abstract

The infections caused by Pseudomonas aeruginosa are life-threatening, due to high intrinsic antimicrobial resistance of this microorganism. The integrons and biofilm formation of P. aeruginosa have a significant role in antibiotic resistance. Therefore, this study aimed to evaluate antibiotic resistance pattern in Pseudomonas aeruginosa isolates with biofilm formation ability. This cross-sectional study from January 2017 to December 2017 was conducted on 78 isolates (58 clinical and 20 environmental) of P. aeruginosa recovered from the 547 samples (439 of clinical and 108 of environmental samples). The isolates were identified by phenotypic and genotypic tests. Kirby-Bauer disk diffusion method was used for susceptibility testing. The prevalence of class 1, 2 and 3 Integrons, rhlA, and lasB genes were determined using Polymerase Chain Reaction (PCR). Biofilm formation was determined using the microtiter plate method. Data analyzed using Stata 14 software and Chi-Square test.The most prevalent resistance was observed against Ticarcillin/Clavulanic Acid (55%). Generally, 56.4% of isolates were producers of strong biofilm in both environmental and clinical isolates. The prevalence of strong biofilm producers in clinical isolates was more than environmental. A significant correlation was observed between Int1, Int2, and rhlA genes with biofilm formation capability (P = 0.02).Regarding >50% of both environmental and clinical isolates were producers of strong biofilm and because the source of clinical isolates may be from the environment, the necessary hygiene measurements should be taken. No significant correlation was observed between lasB gene with biofilm formation capability.