Investigating physiological and genetic characteristics of community acquired infections and potential antimicrobial interventions
type: CreativeWork
description: Staphylococcus aureus and Enterococcus sp. infections occur in hospital and, increasingly, in community settings, with the potential of having different susceptibility to antimicrobial agents. The purpose of this study was to investigate the effect of antimicrobial agents against community acquired S.aureus and investigate antibiotic characteristics, biofilm formation and gene expression following exposure to an antimicrobial agent. The susceptibility of S. aureus isolates and a vancomycin resistant Enterococcus faecium isolate to antibiotics, essential oils and disinfectants were investigated under planktonic conditions using standardised antimicrobial susceptibility tests and the Quantitative suspension and surface tests (EN 1276 and EN 13697) for the disinfectants. Biofilm formation, inhibition and eradication was investigated using the crystal violet (CV) assay while the viability of treated biofilms were investigated using the 2, 3-bis [2-methyloxy-4-nitro-5- sulfophenyl]-2H-tetrazolium-5-carboxanilide (XTT) reduction assay and CFU/ml assay. Multiplex PCR was used to determine the presence of PVL, icaA and IcaD genes as well as SCCmec typing while RT-PCR used to investigate changes in gene expression in five target genes following treatment of PVL CA MSSA and CA MRSA MW2 biofilms with grapefruit EO. The S. aureus isolates all formed biofilms and had similar molecular characteristics however one isolate (CA MRSA SR) was multidrug resistant and PVL negative. The VRE isolate was negative for biofilm formation. In suspension, household bleach and NaDCC caused >5 log reduction in viable counts and on stainless steel surfaces, there was <3.5 log reduction. Against biofilms, Household bleach at 5000ppm caused 100% biofilm eradication within 10 minutes while NaDCC eradicated <50% of the biofilm within one hour at 10,000ppm.The eco-friendly product did not demonstrate any antimicrobial activity against planktonic cells or biofilms. Antimicrobial activity of six essentia…
abstract: Staphylococcus aureus and Enterococcus sp. infections occur in hospital and, increasingly, in community settings, with the potential of having different susceptibility to antimicrobial agents. The purpose of this study was to investigate the effect of antimicrobial agents against community acquired S.aureus and investigate antibiotic characteristics, biofilm formation and gene expression following exposure to an antimicrobial agent. The susceptibility of S. aureus isolates and a vancomycin resistant Enterococcus faecium isolate to antibiotics, essential oils and disinfectants were investigated under planktonic conditions using standardised antimicrobial susceptibility tests and the Quantitative suspension and surface tests (EN 1276 and EN 13697) for the disinfectants. Biofilm formation, inhibition and eradication was investigated using the crystal violet (CV) assay while the viability of treated biofilms were investigated using the 2, 3-bis [2-methyloxy-4-nitro-5- sulfophenyl]-2H-tetrazolium-5-carboxanilide (XTT) reduction assay and CFU/ml assay. Multiplex PCR was used to determine the presence of PVL, icaA and IcaD genes as well as SCCmec typing while RT-PCR used to investigate changes in gene expression in five target genes following treatment of PVL CA MSSA and CA MRSA MW2 biofilms with grapefruit EO. The S. aureus isolates all formed biofilms and had similar molecular characteristics however one isolate (CA MRSA SR) was multidrug resistant and PVL negative. The VRE isolate was negative for biofilm formation. In suspension, household bleach and NaDCC caused >5 log reduction in viable counts and on stainless steel surfaces, there was <3.5 log reduction. Against biofilms, Household bleach at 5000ppm caused 100% biofilm eradication within 10 minutes while NaDCC eradicated <50% of the biofilm within one hour at 10,000ppm.The eco-friendly product did not demonstrate any antimicrobial activity against planktonic cells or biofilms. Antimicrobial activity of six essentia…
author: Adukwu, Emmanuel
language: eng
date published: 2013
date modified: 2026-07-24T03:26:39Z
provider: University of Northampton
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of Northampton