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Developing a real time sensing system to monitor bacteria in wound dressings.

Farrow MJ, Hunter IS, Connolly P - Biosensors (Basel) (2012)

Bottom Line: It is based on impedance sensors that could be placed at the wound-dressing interface and potentially monitor bacterial growth in real time.Impedance was measured using disposable silver-silver chloride electrodes.The main findings were that the impedance profiles obtained by silver-silver chloride sensors in bacterial suspensions could detect the presence of high cell densities.

View Article: PubMed Central - PubMed

Affiliation: Department of Bioengineering, University of Strathclyde, Wolfson Centre, Glasgow, G4 0NW, UK. malcolm.farrow@strath.ac.uk.

ABSTRACT
Infection control is a key aspect of wound management strategies. Infection results in chemical imbalances and inflammation in the wound and may lead to prolonged healing times and degradation of the wound surface. Frequent changing of wound dressings may result in damage to healing tissues and an increased risk of infection. This paper presents the first results from a monitoring system that is being developed to detect presence and growth of bacteria in real time. It is based on impedance sensors that could be placed at the wound-dressing interface and potentially monitor bacterial growth in real time. As wounds can produce large volumes of exudate, the initial system reported here was developed to test for the presence of bacteria in suspension. Impedance was measured using disposable silver-silver chloride electrodes. The bacteria Staphylococcus aureus were chosen for the study as a species commonly isolated from wounds. The growth of bacteria was confirmed by plate counting methods and the impedance data were analysed for discernible differences in the impedance profiles to distinguish the absence and/or presence of bacteria. The main findings were that the impedance profiles obtained by silver-silver chloride sensors in bacterial suspensions could detect the presence of high cell densities. However, the presence of the silver-silver chloride electrodes tended to inhibit the growth of bacteria. These results indicate that there is potential to create a real time infection monitor for wounds based upon impedance sensing.

No MeSH data available.


Related in: MedlinePlus

The magnitude and frequency of the normalised phase angle peak from all 24 vials from the parallel suspension experiments. The majority of the vials with cell densities that reached above 1 × 107 CFU∙mL−1 occurred in the lower right quadrant, while the media only and lower density vials occurred in the upper left quadrant.
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biosensors-02-00171-f006: The magnitude and frequency of the normalised phase angle peak from all 24 vials from the parallel suspension experiments. The majority of the vials with cell densities that reached above 1 × 107 CFU∙mL−1 occurred in the lower right quadrant, while the media only and lower density vials occurred in the upper left quadrant.

Mentions: Examination of the magnitude and frequency of the normalised phase angle peak at 16 h shows a distinction in magnitude between the RN4220 cultures that reached above 5 × 107 CFU∙mL−1 and those that did not. However the frequency of the peak is not completely distinct due to overlapping frequency ranges at approximately 1.58 Hz (Figure 6). This has obvious implications for a detection system that uses frequency bands to discern the absence or presence of bacteria.


Developing a real time sensing system to monitor bacteria in wound dressings.

Farrow MJ, Hunter IS, Connolly P - Biosensors (Basel) (2012)

The magnitude and frequency of the normalised phase angle peak from all 24 vials from the parallel suspension experiments. The majority of the vials with cell densities that reached above 1 × 107 CFU∙mL−1 occurred in the lower right quadrant, while the media only and lower density vials occurred in the upper left quadrant.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4263571&req=5

biosensors-02-00171-f006: The magnitude and frequency of the normalised phase angle peak from all 24 vials from the parallel suspension experiments. The majority of the vials with cell densities that reached above 1 × 107 CFU∙mL−1 occurred in the lower right quadrant, while the media only and lower density vials occurred in the upper left quadrant.
Mentions: Examination of the magnitude and frequency of the normalised phase angle peak at 16 h shows a distinction in magnitude between the RN4220 cultures that reached above 5 × 107 CFU∙mL−1 and those that did not. However the frequency of the peak is not completely distinct due to overlapping frequency ranges at approximately 1.58 Hz (Figure 6). This has obvious implications for a detection system that uses frequency bands to discern the absence or presence of bacteria.

Bottom Line: It is based on impedance sensors that could be placed at the wound-dressing interface and potentially monitor bacterial growth in real time.Impedance was measured using disposable silver-silver chloride electrodes.The main findings were that the impedance profiles obtained by silver-silver chloride sensors in bacterial suspensions could detect the presence of high cell densities.

View Article: PubMed Central - PubMed

Affiliation: Department of Bioengineering, University of Strathclyde, Wolfson Centre, Glasgow, G4 0NW, UK. malcolm.farrow@strath.ac.uk.

ABSTRACT
Infection control is a key aspect of wound management strategies. Infection results in chemical imbalances and inflammation in the wound and may lead to prolonged healing times and degradation of the wound surface. Frequent changing of wound dressings may result in damage to healing tissues and an increased risk of infection. This paper presents the first results from a monitoring system that is being developed to detect presence and growth of bacteria in real time. It is based on impedance sensors that could be placed at the wound-dressing interface and potentially monitor bacterial growth in real time. As wounds can produce large volumes of exudate, the initial system reported here was developed to test for the presence of bacteria in suspension. Impedance was measured using disposable silver-silver chloride electrodes. The bacteria Staphylococcus aureus were chosen for the study as a species commonly isolated from wounds. The growth of bacteria was confirmed by plate counting methods and the impedance data were analysed for discernible differences in the impedance profiles to distinguish the absence and/or presence of bacteria. The main findings were that the impedance profiles obtained by silver-silver chloride sensors in bacterial suspensions could detect the presence of high cell densities. However, the presence of the silver-silver chloride electrodes tended to inhibit the growth of bacteria. These results indicate that there is potential to create a real time infection monitor for wounds based upon impedance sensing.

No MeSH data available.


Related in: MedlinePlus