Is Virulence Gene papGII a Predictor of Urosepsis in Uropathogenic E. coli?

Urosepsis is a life-threatening condition accounting for approximately 20-30% of all sepsis cases and typically arises from ascending infection by uropathogenic Escherichia coli (UPEC). Disease progression is mediated by virulence factors, including adhesins, iron acquisition systems, and toxins. Among these, P fimbriae, particularly papGII adhesin subunit, have been implicated in the transition from uncomplicated urinary tract infection (UTI) to severe urosepsis. This study aimed to evaluate whether papGII carriage, alone or in combination with other UPEC virulence determinants and clinical risk factors, can predict urosepsis.

A total of 60 paired Escherichia coli isolates from concurrent blood and urine samples of adults with clinical sepsis were collected between January and June 2024. Control isolates were obtained from patients with cystitis (n = 28) and pyelonephritis (n = 32). Polymerase chain reaction (PCR) assays were used to detect fifteen virulence-associated genes, including the pap operon (with papG allelic variants), the type 1 fimbriae (fimH), S fimbriae (sfaS), curli fimbriae (csgA), afa/Dr adhesin operon genes, cytotoxic necrotizing factor 1 (cnf1), and the aerobactin biosynthesis (iucD) and receptor (iutA) genes. Associations between gene carriage and clinical groups were analyzed using chi-square tests.

The incidence of urosepsis increased with age, peaking in the 60-69-year age group. Renal disease and catheterization were identified as significant risk factors (p < 0.05). More than 95% of UPEC isolates carried the csgA gene associated with biofilm formation and the iucD gene. The α- hemolysin toxin (hlyA) was significantly associated with urosepsis [X²(1, N = 120) = 6.62, p = 0.03]. No significant differences were observed in the carriage of papA, papC, or fimH. Although papGII was present in 65% of urosepsis-associated UPEC isolates, it did not demonstrate a statistically significant independent association with urosepsis [p = 0.1].

This study demonstrates that while papGII may contribute to the pathogenic potential of UPEC and facilitate systemic infection, it is not a reliable independent predictor of urosepsis.