Association between cell-bound haemolysin and cell-detaching activity of Escherichia coli isolated from children

Abstract

Haemolysin a (HlyA) produced by cell-detaching Escherichia coli, a putative new class of enteric pathogen, is considered to be the main factor responsible for detachment of cells cultured in vitro. HlyA is one of the few E. coli proteins actively secreted into the medium during exponential growth. In the present study 27 HlyA-positive E. coli isolates, randomly selected from stool specimens, produced a cell-bound haemolysin that was detectable during the exponential and stationary growth phases. The influence of both cell-free and cell-bound haemolysins of the selected isolates on cell-detaching activity of E. coli in vitro was determined. The results suggest that cell-bound haemolysin rather than cell-free HlyA was responsible for the cell-detaching activity of E. coli strains tested.

Correlation Between hlyA and cnf1 Virulent Genes with Antibiotic Resistance and non-ESBLs Escherichia coli Isolates Collected from Patient with Urinary Tract Infections in Kerman, Iran

“…Ability of E. coli in the pathogenesis is dependent on the virulent factors (2,3). Several virulent factors including hemolysin (hlyA) and cytotoxic necrotizing factor type 1 (cnf1) are responsible for pathogenic potential of uropathogenic E. coli isolates (UPEC) (3,4). These virulence factors are involved in damage to the tissues as well as bacterial dissemination (3,4).…”

“…This bacterium is the most common cause of urinary tract infections (UTIs) in all age groups (2). Ability of E. coli in the pathogenesis is dependent on the virulent factors (2,3). Several virulent factors including hemolysin (hlyA) and cytotoxic necrotizing factor type 1 (cnf1) are responsible for pathogenic potential of uropathogenic E. coli isolates (UPEC) (3,4).…”

“…Several virulent factors including hemolysin (hlyA) and cytotoxic necrotizing factor type 1 (cnf1) are responsible for pathogenic potential of uropathogenic E. coli isolates (UPEC) (3,4). These virulence factors are involved in damage to the tissues as well as bacterial dissemination (3,4). Antibiotic resistance is another important factor in ability of E. coli in the pathogenesis and increased of morbidity and mortality of patients (5).…”

An Outbreak of Diarrhea in Mandera, Kenya, Due to Escherichia coli Serogroup O-Nontypable Strain That Had a Coding Gene for Enteroaggregative E. coli Heat-Stable Enterotoxin 1

“…38 Alpha-hemolysin (HlyA) produced by CDEC is considered to be the main factor responsible for detachment of cells cultured in vitro. 39 We validated the presence of hlyA by PCR in the EASTEC outbreak strain, but it was negative. The strains were also tested for hemolytic activity.…”