الفهرس 
Introduction and Aim of the workOnly 14 pages are availabe for public view
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Abstract
Furthermore, the MICs for P. mirabilis isolates for some biocides
were determined. Chlorhexidine had MICs of 50, 100, 200 and 400 μg/ml
for 16, 12, 48, and 24% of the isolates, respectively. The study also revealed
that the MICs of thiomersal against Proteus isolates 30, 60 and 10 % was
0.2, 0.3 and 0.5 μg/ml, respectively against thiomersal. Povidone-iodine had
MICs of 2000 and 2500 μg/ml. The MIC range of chlorocresol was 100-150
μg/ml, while MIC range of hydrogen peroxide was 100-300 μg/ml. Also,
the MIC range determined for cetrimide was 50-800 μg/ml.
One of the most important virulence factors that Proteus has is
urease enzyme production. Urease breaks down urea in urine into carbon
dioxide and ammonia; this causes a prominent increase in the urine pH and
precipitation of calcium and magnesium struvite crystals. Crystal formation
can lead to catheter occlusion and stone formation in the kidney. Moreover,
P. mirabilis has a characteristic swarming movement that allows it to move
over catheter surfaces. Also, catheters serve as an excellent surface for
biofilm formation. P. mirabilis has a variety of fimbriae that cause adhesion
of P. mirabilis to solid surfaces as catheters. The most studied is the
mannose resistant fimbriae MR/P that allows P. mirabilis adherence to
catheter surface, which is the initiating step for biofilm formation. Also,
presence of MR/P fimbriae was associated with the development of
pyelonephritis.
In the current study, some compounds that can act as inhibitors of
formation of virulence factor of P. mirabilis were tested. The test
compounds studied were diclofenac sodium, ibuprofen, sodium salicylate
(anti-inflammatory agents), orphenadrine (muscle relaxant), bromohexine
(mucolytic), ascorbic acid (antioxidant), EDTA (chelating agent).
Sub-inhibitory concentrations of each of the test compounds were
screened for their ability to inhibit urease enzyme. Diclofenac, ibuprofen and sodium salicylates did not show any inhibitory effect on urease activity
at concentrations 1.56, 3.125, 6.25 mg/ml, respectively. Furthermore,
orphenadrine also did not show any inhibitory effect at concentrations
0.94, 1.87 mg/ml. On the other hand, bromohexine, ascorbic acid and
EDTA showed inhibitory effect on urease enzyme.