Bacteriological and molecular study of Staphylococcus aureus isolated from patients with urinary infection in Thi-Qar province

Urinary tract infection (UTI) is one of the most common infectious diseases in humans both in the clinical and community settings. involvement of Gram-positive bacteria cannot be ruled out in relation to UTI. Staphylococcus aureus is one of such agents involved in the infection that is capable of invading the urinary tract. Although S. aureus accounts to 0.5–6% of UTI. This study aims to detect the molecular genotyping and genetic variation of S. aureus isolated from UTIs patients after its isolation and diagnosis, depending on the cultural and biochemical examinations and confirmation by API-20 and Vitek2 compact systems. Two hundred clinical (urine) specimens were collected during the period (February to June 2021); from patients who were complained from İYEs at AL-Hussein Teaching Hospital in AL-Nasiriyah City, South Iraq. diagnostic results show that 133 out of the 200 specimens gave positive bacterial cultures as Staphylococcus aureus. According to gender, females recorded the high İYE rates with 136 cases (68%) (p≤0.01). the antibiotic susceptibility profile for these isolates was examined against Fourteen types of antibiotics. Highest resistance was recorded against Ampicillin, Cefoxitin, Tetracycline, Clindamycin and Trimethoprim-Sulfamethoxazole with a percentages of (100%), (97.7%), (76.6%), (71.4%), and (54.1%), respectively while Erythromycin (43.6%) followed by Doxycycline (42.8%). On the other hand the tested isolates showed a high degree of susceptibility towards vancomycin and novobiocin. PCR technique was used to detect the presence of (spa) gene as a virulence gene in S. aureus isolated from İYE patients. All S. aureus isolates (n=55) were amplificated to (spa) gene at (1400-260 bp) with a positive reaction of 55 (100%), with note the genotyping of this gene. also, (tst-1) gene detected in (20%) of all S. aureus isolates with a molecular size of (538 bp). In a DNA sequencing analysis method , the genetic variation (substit UTI on Mutations) analysis in v immunoglobulin G binding protein A (spa) gene between local S. aureus isolates (IQ-UTI.1-IQ-UTI.2) and NCBI-Blast related S. aureus isolate were find 4 into 5 substitİYEon mutations at total genetic variation percentage ranged (0.84-1.05%).While the genetic variation analysis in toxic shock syndrome toxin- 1 (tsst-1) gene between local S. aureus isolates (IQ- UTI.3) and NCBI-Blast related S. aureus isolate were find one substit UTI on mutation at total genetic variation percentage ranged (0.23%).