ORCID

0000-0002-5812-9013

Department

Biological Sciences

Year of Study

4

Full-time or Part-time Study

Full-time

Level

Postgraduate

Presentation Type

Oral Presentation

Supervisor

Dr Craig Murphy

Supervisor

Dr Eamonn Culligan

Abstract

Background

Nosocomial pathogens are responsible for chronic and persistent infections partly due to their ability to form protective biofilms which enhance their antibiotic tolerance. Biofilm disruption combats antimicrobial resistance as dispersed cells regain antibiotic susceptibility. The goal of this study was to evaluate the antibiofilm potential of isolates from marine environments against a pathogen panel consisting of MRSA and clinical Staphylococcus aureus strains, Acinetobacter baumannii and Escherichia coli pathogens.

Method

A large bank of saltwater bacterial isolates was cultured in glucose-supplemented trypticase soy broth (TSBg) and resulting colonies were screened against the pathogen panel. Isolates of interest were further examined for bactericidal and antibiofilm activity.

All bacterial strains and isolates were standardised using McFarland standards. The minimum biofilm inhibitory and eradication concentrations (MBIC and MBEC) were measured using a crystal violet (0.1%) staining assay. Bacterial viability within biofilm was determined as the reduction [%] in metabolic activity as determined by the 2,3,5-triphenyltetrazolium chloride (TTC) assay.

Results

Two saltwater isolates significantly reduced the ability of all the tested strains form biofilm. MBIC50 was achieved for S. aureus, A. baumannii and E. coli at an isolate concentration of 7.8x103, 1.2x104 and 6.25x103 CFU/mL, respectively. An increase in biofilm eradication and reduction in metabolic activity was observed solely against S. aureus and E. coli strains.

Conclusions

Selected saltwater isolates demonstrated inhibitory and disruptive potential against biofilm forming strains. However, further investigation is required to optimise their activity against mature biofilms.

Keywords:

biofilm, pathogens, microbiology

Start Date

2-11-2023 12:15 PM

End Date

2-11-2023 12:30 PM

Included in

Microbiology Commons

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Nov 2nd, 12:15 PM Nov 2nd, 12:30 PM

Investigating the ability of saltwater isolates to inhibit biofilm formation by clinically significant pathogens

Background

Nosocomial pathogens are responsible for chronic and persistent infections partly due to their ability to form protective biofilms which enhance their antibiotic tolerance. Biofilm disruption combats antimicrobial resistance as dispersed cells regain antibiotic susceptibility. The goal of this study was to evaluate the antibiofilm potential of isolates from marine environments against a pathogen panel consisting of MRSA and clinical Staphylococcus aureus strains, Acinetobacter baumannii and Escherichia coli pathogens.

Method

A large bank of saltwater bacterial isolates was cultured in glucose-supplemented trypticase soy broth (TSBg) and resulting colonies were screened against the pathogen panel. Isolates of interest were further examined for bactericidal and antibiofilm activity.

All bacterial strains and isolates were standardised using McFarland standards. The minimum biofilm inhibitory and eradication concentrations (MBIC and MBEC) were measured using a crystal violet (0.1%) staining assay. Bacterial viability within biofilm was determined as the reduction [%] in metabolic activity as determined by the 2,3,5-triphenyltetrazolium chloride (TTC) assay.

Results

Two saltwater isolates significantly reduced the ability of all the tested strains form biofilm. MBIC50 was achieved for S. aureus, A. baumannii and E. coli at an isolate concentration of 7.8x103, 1.2x104 and 6.25x103 CFU/mL, respectively. An increase in biofilm eradication and reduction in metabolic activity was observed solely against S. aureus and E. coli strains.

Conclusions

Selected saltwater isolates demonstrated inhibitory and disruptive potential against biofilm forming strains. However, further investigation is required to optimise their activity against mature biofilms.