Characterization of Escherichia coli isolated from urinary tract infection and association between virulence expression and antimicrobial susceptibility

Abstract

Background The capacity of antibiotics to modulate bacterial virulence has raised concerns over the appropriateness of antibiotic therapies, including when dosing strategies fall below sub-therapeutic levels. In this work, we investigated the ability of antibiotics to influence virulence in Escherichia coli isolated from urinary tract infection (UTI). Results Out of 120 isolates, 32.5% carried pap, 21.7% carried hlyA, and 17.5% carried cnf. The predominant B2 phylogroup was significantly associated with the quinolone-resistant isolates. A significant association was seen between the presence of hlyA hemolysin and susceptibility to ceftriaxone and ciprofloxacin (P < 0.05). Sub-inhibitory concentrations of both antibiotics reduced the levels of hlyA expression and hemolysis in isolates treated with antibiotics compared to untreated isolates (P < 0.05). Growth rate assay showed that the decrease in hlyA expression was not an effect of decreased growth rate. Conclusion Our study indicated the inhibitory effect of ciprofloxacin and ceftriaxone on the level of hemolysis, suggesting that the sub-inhibitory concentrations of these antibiotics may affect the outcome of infections. Further studies, including animal models may elucidate the outcome of virulence modulation by these antibiotics in UTI pathogenesis.

Correlation between antimicrobial resistance, biofilm formation, and virulence determinants in uropathogenic Escherichia coli from Egyptian hospital

“…Studies performed on UPEC in other countries also reported lower hemolysis rates of 41.5% and 32.3%, in Mexico and Nepal, respectively [ 70 , 91 ]. We also observed that beta-hemolytic isolates were significantly more susceptible to cephalosporins, CIP, and GEN, which may be due to the reduced virulence as a cost of acquiring resistance, as reported previously [ 46 , 73 ]. Hemolytic isolates were also significantly associated with biofilm formation, which agrees with previous reports stating that biofilm-forming UPEC had a higher rate of hemolysin production [ 92 , 93 ].…”

“…The isolates' total DNA was extracted using the boiling lysis technique [ 46 ]. Briefly, the overnight culture suspensions of isolates were centrifuged, and the cell pellets were resuspended in 200 µL of nuclease-free water.…”

Survival and Virulence Potential of Drug-Resistant E. coli in Simulated Gut Conditions and Antibiotic Challenge

“…However, the effect of sub-MIC level of ciprofloxacin on the virulence gene expression of E. coli was widely studied. For instance, reduced expression of iron acquisition genes, fimbriae genes and hemolysin A gene was observed on exposure to sub-MIC level of ciprofloxacin [3,35]. It was also found that the sub lethal concentration of antibiotics, such as ceftriaxone, can modulate the expression of OMPs in S. Typhi [13].…”

Detection of resistance genes (gyrA,qepA,drf1,drf17) for E.coli in Iraqi aquatic environment ( symbols for genes are italicized (e.g., IGF1) in all the text

“…E. coli is one of the intestinal microbiomes for more than 90% of people 2 , E. coli represents commensal bacteria in the intestine as microflora of animals and humans, some E. coli strains can cause disease in humans, mammals, and birds 3 .E. coli is one of the bacteria that have recently become resistant to different classes of antibiotics through various mechanisms including efflux pump, and decreased cell permeability 4 . They are highly adaptable bacteria that can survive and grow in outdoor environments, involving the river 5 .…”