Study of Some Virulence Factors of Proteus mirabilis Isolated from Urinary Stones Patients

A total of 125 specimens of stones and urine were collected from urinary stone patients from (June to December, 2012). According to primary identification, which based on macroscopic and microscopic characteristics and biochemical tests, 25 (20%) and 100 (80%) of isolates were identified as Proteus and non-Proteus, respectively. The 25 Proteus isolates were finally identified as Proteus mirabilis based on Vitek 2 system and polymerase chain reaction (PCR) technique by using target gene 16S rRNA. The multiple logistic regressions results showed that the age ˃ 40 years old was a risk factors that significantly associated with increased incidence of P. mirabilis in urinary stone patients, as P = 0.02, and Odd’s ratio (OR) was 4.889 (1.7-14.057), while in relation to gender, the analysis revealed that they were statistically non-significant as OR was 1.174 (0.488-2.822) as well as P=0.720. Some virulence factors of all isolates were investigated by Qualitative and Quantitative assay. Qualitative assay showed that all isolates (100%) were positive to urease, biofilm, Adhesion factors, and swarming activity. Whereas, 40% of isolates were positive to protease and ESBL, 96% and 76% of isolates were positive to agglutination and β-lactamase, respectively. Quantitative assay revealed that all tested isolates were significantly differences P˂ 0.05 in the production of the tested virulence factors. The urease production activity range from 59 to 129 U/ml, whereas the protease production activity ranged from 2.5 to 8 U/ml; the mean of adhering to uroepithelial cell ranged from (20-45) bacteria/cell. The mean of optical density ranged from (0.028-033) at OD630 and the percentages of biofilm activity were 60%, 24% and 16% as strong, moderate and weak biofilm, respectively. The mean of swarming growth activity of P. mirabilis isolates ranged from (3-67mm) and 40%, 32%, 8%, and 20% of isolates showed strong, moderate, weak, and very weak swarming activity, respectively.

The Role of Lipopolysaccharide and O-Antigen of Proteus Mirabilis in Urinary Stones Formation, In-Vitro Study

The ability to induce stone formation in-vitro of Proteus mirabilis isolates was investigated using whole bacterial cell, lipopolysaccharide, and O-antigen of these isolates. The results showed that all three parts have the ability to form crystallization in artificial urine solution, which based on the differences in urease activity and chemical structure of LPS and O-antigen. The whole bacterial cell of isolate No. 6 (P. mirabilis O18) revealed significant differences (P˂ 0.05) in the ability to bind with calcium (251.5 µg/ml) and magnesium (75.4 µg/ml) compared with the whole bacterial cell of isolate No. 14 (P. mirabilis O3) and isolate No. 3 (P. mirabilis O16), where the calcium concentrations were 238.77 µg/ml and 227.12 µg/ml, respectively; and magnesium concentrations were 53.34 µg/ml and 37.68 µg/ml for isolates No. 14 and 3, respectively. In contrast, LPS and O-antigen of isolates No. 14 and 3 showed significantly differences (P˂ 0.05) in the ability to metal binding with calcium (25.77 µg/ml and 25.06 µg/ml), respectively, and magnesium (6.6 µg/ml and 7.5 µg/ml), respectively, compared with LPS and O-antigen of isolate No. 6, where the calcium and magnesium concentration were 18.03 µg/ml and 3.16 µg/ml, respectively