Frequency of hlyA, hlyB, hlyC and hlyD genes in uropathogenic Escherichia coli isolated from UTI patients in Shiraz

Abstract

Background and objectives: One of the most important causes of urinary tract infections (UTI) is . The infection is mainly due to the uropathogenic strain (UPEC), which has key virulence factors, including hemolysis. In this study, we evaluated the frequency of , , and genes in UPEC strains isolated from clinical samples from Shiraz city, Iran.Materials and methods: 130 urine samples with suspected UTI were collected from Shiraz medical centers and cultured on blood agar and EMB media. Colonies were then characterized by biochemical methods. The genomes were extracted and the presence of hemolysis genes was detected by polymerase chain reaction (PCR) using gene specific primers and 16S . Drug resistance was assessed by using 10 antibiotic disks in the disk diffusion method, according to CLSI criteria.Results: Out of the 130 collected UTI samples, 100 were identified as UPECs. Within isolates, the gene had the highest frequency – 95% – and had the lowest, with 23%. The frequencies of and genes were calculated as 50% and 43%, respectively. The rates of antibiotic resistance to Azithromycin, Ampicillin, Cefotaxime, Nalidixic Acid, Tetracycline, Trimethoprim-Sulfamethoxazole, Cefepime, Aztreonam, Gentamicin, and Nitrofurantoin were 95%, 86%, 68%, 66%, 65%, 64%, 51%, 46%, 44%, 14%, respectively. 98% of these isolates belonged to the MDR group.Conclusion: This study shows diversity of hemolysis virulence factor in UPECs and unique UPEC drug resistance that would indicate a high antibiotic use in the general population.

Keywords

• antibiotic resistance
• hly gene
• uropathogenic escherichia coli
• urinary tract infection
• 16s rrna