Introduction: Pseudomonas aeruginosa (P. aeruginosa), which is a non-fermentative Gram
the negative opportunistic pathogen is the leading cause of many infections including
pneumonia, wound, and urinary tract infection. Aim of the work: To determine the ability of
P. aeruginosa clinical isolates to produce biofilm. To detect expression of Lec A gene and
biofilm development. Materials and methods: Sample Collection and Microbiological
Processing: Samples were collected and sent directly to the microbiology laboratory of
Medical Microbiology and Immunology Department, Faculty of Medicine, Minia University
for bacteriological study. It was done in the period from April 2017 to December 2017. Pus
from wound was collected by using sterile ordinary swab, then plates of Cetramide agar
media were inoculated and incubated under aerobic conditions at 37°C and a Gram stained
film was done. Results: Patients and bacterial isolates: This study was conducted at Minia
University Hospitals during the period from April 2017 till December 2018. Two hundred
and twenty two samples were collected from surgical wounds from outpatient clinic and inpatient surgery department. Out of 222 bacterial isolates, one hundred isolates of P.
aeruginosa were detected. They showed growth on cetramide agar. They were citrate and
oxidase positive. They were indole test negative, methyl red test negative and VP test
negative. TSI test showed red butt and red slant. Conclusion: 1- The degree of biofilm
formation differs between different P. aeurginosa strains. 2- Lec A gene has a significant role
in biofilm formation. 3- Imipenem is highly effective against P. aeurginosa in vitro. Biofilm
producing strains have higher resistance to antibiotics even in their planktonic form than nonbiofilm-producing strains. Recommendations: Large-scale studies on a large number of P.
aeruginosa clinical isolates to study their abilities to form biofilm and its relation to Lec A
gene and antibiotic resistance.