الفهرس 
An Overview on BiofilmOnly 14 pages are availabe for public view
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Abstract
Bacteria exist, in most environments, as complex organised communities of sessile cells embedded within a matrix of self-produced, hydrated extracellular polymeric substances known as biofilms. Bacterial biofilms contribute to more than 80% of hospital-acquired and community acquired infections. Klebsiella pneumoniae and Pseudomonas aeurginosa are two important examples of the pathogens able to form biofilms. The capability to form biofilm by these organisms can be considered as a virulence factor. Infections caused by biofilm forming pathogens typically exhibit tolerance to antimicrobial and immunological challenge. This renders them difficult, sometimes impossible, to treat using conventional chemotherapeutic agents. Effective alternative approaches for prevention and eradication of biofilm associated infections are therefore urgently required.
This study aimed to show the ability of Lactobacillus fermentum, a probiotic Lactobacilli, to inhibit the biofilm formation by different strains of Klebsiella and Pseudomonas isolated from different clinical samples.
In this study forty isolates of K. pneumoniae spp.pneumoniae and P. aeurginosa were obtained from different clinical samples from patients admitted to Ain Shams University Pediatric surgery and General surgery departments at Surgery hospital. Clinical samples from which isolates were taken, included 19 (47.5%) pus from surgical wounds, 11 (27.5%) from urine, 8 (20%) from sputum and 2 (5%) from urinary catheters.
All samples were cultured on MacConkey’s agar media then the isolated organisms were identified by colonial morphology, Gram staining, and biochemical reactions and confirmed by API. Antibiotic sensitivity of the isolated bacteria was done using disc diffusion method to avoid strains repetition, then isolated bacteria were tested for their ability to form biofilm using MTP based system.
The effect of Lactobacillus fermentum were tested on good and intermediate biofilm forming isolates.
It was found that:
1- Klebsiella strains showed a high resistance to ceftazidime 90.91% followed by pipracillin 77.27%, ciprofloxacin 72.73%, amikacin 31.83%, gentamycin 22.73% and imipenem 4.55%.
2- Pseudomonas strains showed a high resistance to to ceftazidime 50% followed by pipracillin and ciprofloxacin 38.89%, gentamycin 33.33%, amikacin 22.22% and imipenem 11.11%.
3- Four out22 (18%) of of K. pneumoniae spp.pneumoniae isolates were good biofilm producers, 4.5% (1/22) were intermediate biofilm producers and 77.2% (17/22) were poor biofilm producers.
4- One out of 18 (5.55%) of P. aeurginosa isolates were good biofilm producers, 33.33% (6/18) were intermediate biofilm producers and 61.11% (11/18) were poor biofilm producers.
5- Nine out of 19 (47%) of pus samples were biofilm producers, 9% (1/11) of urine samples were biofilm producers, 25% (2/8) of sputum samples were biofilm producers no isolates of urinary catheter were biofilm producers.
6- The degree of biofilm formation by K. pneumoniae spp.pneumoniae and P. aeurginosa strains before and after adding of Lactobacillus fermentum was statistically significant.