ABSTRACT

BACKGROUND AND OBJECTIVE: Extraintestinal Escherichia coli bacteria is the main reason behind the urogenital infections in humans. Several virulence factors such as cytotoxin genes coding for proteins, adhesion, siderophore receptors and outer-membrane protease are detected within the extraintestinal  Escherichia coli.  This study aimed to investigate the distribution of genes encoding virulence factors and their correlation with phylogenetic groups in Escherichia coli isolates. The samples were taken from the patients referring to the women’s clinics in the city of Zabol, Iran.

METHODS: In this study, 132 Escherichia coli bacteria were isolated through standard, biochemical methods while all isolated genomic DNA was extracted by boiling. The presence of Cytotoxin Necrotizing Factor 1 (CNF1), IrgA homologue adhesin (iha), iron-responsible protein (irp2) and  outer-membrane protease (ompT) was studied via Multiplex-PCR method. Furthermore, utilizing Triple-PCR method, we were able to carry out phylogenetic grouping of all the isolates using the presence or absence of such genes as chuA, yjaA and TspE4.C2 piece.

FINDINGS: Among 132 isolates, the prevalence of the following genes were determined as CNF1 (10%), iha (8%), irp2 (45%) and ompT (63%). Moreover, for the total number of 132 Escherichia coli isolates, 14%, 7%, 60% and 19% were placed in phylogenetic groups A, B1, B2 and D respectively. Most of the distribution of the genes encoding virulence  factors were observed in the B2 group, with an abundance of CNF1 (100%), iha (5.62%), irp2 (01/73%) and ompT (44/84%) in comparison with the other groups.

CONCLUSION: This study concluded that ompT and irp2 are the most frequent genes to isolate virulence factors of extraintestinal Escherichia coli from the genital tract infections. This finding could provide researchers with information regarding the importance of the pathology of reproductive tract infections and thus, help them with discovering more effective remedies.