Genotyping of Escherichia coli Causing Vaginal Infection in Dysplastic Patients with Similar Genetic Backgrounds Between Commensal and Virulent Strains

Background: Escherichia coli in the vagina includes several virulence factors in its genome mobile genetic elements and can facilitate colonization, mainly in immunosuppressed patients. Objectives: This work aimed to demonstrate that E. coli strains of vaginal origin isolated from dysplastic patients possess virulence and resistance genes Methods: This study included one hundred and five E. coli strains isolated from women with cervical dysplasia and vaginal infection. The strains were characterized by antimicrobial susceptibility. The Clermont algorithm performed the phylogenetic assignment. The structure of class 1 integrons was performed by identifying integrase (int1), the variable region, and qacEΔ1-sul1 genes. The variable region was amplified, sequenced, and analyzed. Enterobacterial repetitive intergenic consensus (ERIC) PCR and virus typing typed strains with identical genetic arrangements by detecting virulence genes related to cytotoxicity, adherence, and iron uptake. Results: Escherichia coli strains showed great resistance to β-lactams and quinolones, and phylogenetic assignment showed that the group A/C was highly predominant. Sixteen integrons were identified, with monogenic arrays represented by aadA1, dfrB4dfrA7, dfr2D, and dfrA17 cassettes. The prevalence of the biogenic arrays aadA1/dfrA1 and aadA5/dfrA17 was lower than that of blaOXA-1/aadA1. Concerning virulence genes, fimH, traT, and iutA were the most predominant. Conclusions: The high incidence of virulence and resistance factors in commensal and virulent strains of E. coli revealed potential tools in the pathogenesis of vaginal infection.

Relationships between Virulence Factors and Antimicrobial Resistance among Escherichia coli Isolated from Urinary Tract Infections and Commensal Isolates in Tehran, Iran

Objectives

Uropathogenic Escherichia coli (UPEC) are the major cause of urinary tract infections (UTIs). Here, we determined whether sensitivity to antibiotics was related to the prevalence of iron scavenging genes, or to biofilm and hemolysis formation.

Methods

A total of 110 UPEC and 30 E coli isolates were collected from the urine of UTI patients and feces of healthy individuals without UTI, respectively. The presence of iron receptor genes and phenotypic properties were evaluated by polymerase chain reaction and phenotypic methods, respectively. Susceptibility to routine antibiotics was evaluated using the disc diffusion method.

Results

The prevalence of iron scavenging genes ranged from 21.8% (ireA) to 84.5% (chuA) in the UPEC. Resistance to ceftazidime and cefotaxime was significantly correlated with the presence of fyuA and iutA iron genes. Biofilm production was significantly associated with the prevalence of fyuA and hma iron genes. A higher degree of antibiotic resistance was exhibited by isolates that produced biofilms than by their non-biofilm producing counterparts.

Conclusion

Our study clearly indicates that biofilm production is associated with antibiotic resistance, and that iron receptors and hemolysin production also contribute to reduced antibiotic sensitivity. These results further our understanding of the role that these virulence factors play during UPEC pathogenesis, which in turn may be valuable for the development of novel treatment strategies against UTIs.