Detection of Biofilm Formation and Some Virulence Factors in Pseudomonas aeruginosa, and the Effect of Some Antibiotics

Abstract

Objective. Pseudomonas aeruginosa is a present everywhere and opportunistic bacterium pathogen. The existence of numerous virulence factors i.e. exo-toxin, exo-enzyme genes, and biofi lm may be contributed in the pathogenesis and pathogenicity of the bacterium. The goals of the present work were to detect biofilm formation, some biofilm genes, and the effect of antibiotics against P. aeruginosa. Methods. All isolates were identified using API 20E and 16S rRNA techniques. The microtiter plate method (MTPM) was used to detect biofi lm formation. Th e polymerase chain reaction (PCR) was used to fi nd some virulence genes e.g. pelA, pslA. Results. A total of 64 P. aeruginosa isolates were identified as P. aeruginosa. The majority of infection belonged to burn infections — 27 (42.2%), followed by ear — 17 (26.5%), and urine — 20 (31.3%). The results of biofilm detection using MTPM showed that all P. aeruginosa isolates were able to produce biofilm but at different levels. PCR technique was used to detect biofilm genes. Studies showed that 61 (95.30%) and 63 (99.32%) isolates carried pelA and pslA genes, respectively. Moreover, a susceptibility test was used to select 10 antibiotics. P. aeruginosa isolates were resistant to cefotaxime — 61 (95.3%), carbenicillin — 59 (92.2%), ampicillin — 38 (59.4%), piperacilin/tazobactam — 29 (45.3%), streptomycin — 28 (43.8%), moxifloxacin — 27 (42.4%), ticarcilin — 26 (40.6%), ciprofloxacin — 24 (37.5%), gentamicin — 20 (31.3%), and neomycin — 13 (20.3%). Conclusions. Biofilm is produced by P. aeruginosa at different levels. The molecular technique showed that the pelA and pslA genes are associated with the form of biofilm in P. aeruginosa isolates. The susceptibility tests showed that the most active antibiotics against P. aeruginosa were neomycin, gentamycin, and ciprofloxacin, respectively.