ORCID

0000-0002-2629-5148

Department

Biological Sciences

Year of Study

2

Full-time or Part-time Study

Full-time

Level

Postgraduate

Presentation Type

Poster

Supervisor

Eamonn Culligan

Supervisor

Roy Sleator

Supervisor

Craig Murphy

Abstract

Asymptomatic bacteriuria (ABU) is the presence of bacteria in urine, resembling a state of commensalism. Bacteria are characterised as ABU when they have been isolated from two consecutive urine samples (≥ 105 CFU/ml) from individuals, but without symptoms attributable to a urinary tract infection (UTI). ABU Escherichia coli strains have evolved from uropathogenic ancestors and lack virulence factors associated with uropathogenic E. coli (UPEC). UPEC are the main etiological agent of urinary tract infections (UTIs), attributable to > 80% of cases. The frequency at which multidrug-resistant UPEC are isolated is affecting guidelines for use of former first-line antibiotics for UTIs, whereby fluoroquinolones are now only recommended provided that the frequency of local resistance in UPEC is ≤ 10%. Bacterial interference has been established against UPEC using a prototype ABU strain, E. coli 83972. ABU strains displaying this antagonism against UPEC could be potential non-antibiotic therapies for UTIs, however the mechanism behind this action is unknown. This study aims to screen and characterise the inhibition of UPEC by ABU isolates, and further differentiate these two classes of E. coli. Preliminary screening assays have detected antagonism between an ABU strain against an initial panel of UPEC. Further assays have unveiled this activity is potentially due to the production of an antimicrobial peptide. ABU strains will be analysed for peptide or bacteriocin-encoding genes following genome sequencing. Additionally, genome comparisons will be conducted to differentiate between fitness factors in ABU and UPEC. Further competition assays will be conducted in in vitro urogenital-like environments to evaluate the safety and suitability as non-antibiotic therapies for UTIs.

Keywords:

Antibiotic Resistance, Asymptomatic Bacteriuria, Bacterial Interference, Biotherapeutic, Uropathogenic E. coli, UTI

Start Date

June 2022

End Date

June 2022

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Jun 14th, 2:15 PM Jun 14th, 2:30 PM

Investigating the antagonistic activity of asymptomatic bacteriuria against uropathogenic E. coli.

Asymptomatic bacteriuria (ABU) is the presence of bacteria in urine, resembling a state of commensalism. Bacteria are characterised as ABU when they have been isolated from two consecutive urine samples (≥ 105 CFU/ml) from individuals, but without symptoms attributable to a urinary tract infection (UTI). ABU Escherichia coli strains have evolved from uropathogenic ancestors and lack virulence factors associated with uropathogenic E. coli (UPEC). UPEC are the main etiological agent of urinary tract infections (UTIs), attributable to > 80% of cases. The frequency at which multidrug-resistant UPEC are isolated is affecting guidelines for use of former first-line antibiotics for UTIs, whereby fluoroquinolones are now only recommended provided that the frequency of local resistance in UPEC is ≤ 10%. Bacterial interference has been established against UPEC using a prototype ABU strain, E. coli 83972. ABU strains displaying this antagonism against UPEC could be potential non-antibiotic therapies for UTIs, however the mechanism behind this action is unknown. This study aims to screen and characterise the inhibition of UPEC by ABU isolates, and further differentiate these two classes of E. coli. Preliminary screening assays have detected antagonism between an ABU strain against an initial panel of UPEC. Further assays have unveiled this activity is potentially due to the production of an antimicrobial peptide. ABU strains will be analysed for peptide or bacteriocin-encoding genes following genome sequencing. Additionally, genome comparisons will be conducted to differentiate between fitness factors in ABU and UPEC. Further competition assays will be conducted in in vitro urogenital-like environments to evaluate the safety and suitability as non-antibiotic therapies for UTIs.