The Similarity of the Nocleitide Sequence of 16S rRNA and rec A Genes between Strains of E. coli and P. mirabilis from Staghorn Kidney

Escherichia coli and Proteus mirabilis are the most isolated bacteria from kidney stones.16S rRNA and recA genes show evolutionary relationship among bacteria. The aim of this study is to detect and isolate Escherichia coli and Proteus mirabilis from Staghorn kidney stones obtained from patients at LabafiNejad Hospital and investigation of genetic relationship between 16S rRNA and recA genes in these two bacteria.
One hundred and fifty stone samples were obtained from patients referred to the surgical ward of LabafiNejad Hospital. They have examined for recognizing material of staghorn stones and exictene of bacteria. Cultured bacteria were identified by Phenotypic, biochemical and PCR tests, and antibiotic resistant of identified bacteria was performed. For investigation of genetic relationship between 16S rRNA and recA genes in identified strains of Escherichia coli and Proteus mirabilis were sequenced and phylogenetic tree was drawn for them by MEGA4 software.
Results showed that out of 150 patients, 73.3% were male and 26.7% were female and 44% stones samples were culture positive. The most identified species consisted of Escherichia coli 22.8%, Proteus mirabilis 18.2%, Staphylococcus aureus 13.6%, Staphylococcus saprophyticus 12.2% and Staphylococcus epidermidis 12.2%. 16S rRNA gene sequences similarities in Escherichia coli and Proteus mirabilis strains were 96% and 97% respectively. Also the results of recA gene sequences analysis showed that all genes had 98% similarity. Among stones with positive bacterial cultures, the most composition of stone was Calcium oxalate 57.5%.
In the present study, the phylogenetic results showed that the recA is better than 16S rRNA gene for investigation of genetic relationship between16S rRNA and recA genes in identified strains Escherichia coli and Proteus mirabilis in kidney stone samples. With regard to the comparison of recA and 16S rRNA gene sequences, it is appeared that recA gene is slightly more accurate than 16S rRNA gene and it is better to use recA gene instead of 16S rRNA gene of course it needs more information.