Identification of aatA, aap and aggR plasmid genes in uropathogenic Echerichia coli (UPEC) from the west Tehran laboratories

Urinary tract infection with E.coli (UPEC) is one of common bacterial infections. This study investigates the distribution of three pathogenic genes, including aggR, aap and aatA and their linkage with the gene stbA (gene essential for maintaining Plasmid pAA) in UPEC infections.

E.coli samples from 244 patients with urinary tract infection were collected from clinical laboratories in west of Tehran (Iran) between 2008 and 2009. E.coli isolation was performed with standard laboratory methods. DNA was extracted from samples and the presence of pathogenic genes aap, aggR, aatA and stbA was investigated by PCR method.

Among 244 UPEC samples, 104 samples did not have any of three pathogenic genes, but 14 samples carried stbA gene. Among 140 UPEC samples with pathogenic genes, 94 (46.6%) aap gene, 52 (23%) aggR gene and 80 (35.4%) aatA gene were identified alone or in combination with each other. Also, the presence of stbA gene in 140 samples containing pathogenic gene or genes was not persistent as only 44 samples had this gene.

Our results showed that the pathogenic plasmid aggR, aap and aatA gene patterns in E.coli change in different clinical settings. These three genes exit from one loci on plasmid and locate elsewhere. This study also showed that aggR, aap and aatA genes are not restricted to EAEC strains.