Limits...
Efficacy of ultraviolet C light at sublethal dose in combination with antistaphylococcal antibiotics to disinfect catheter biofilms of methicillin-susceptible and methicillin-resistant Staphylococcus aureus and Staphylococcus epidermidis in vitro

View Article: PubMed Central - PubMed

ABSTRACT

Background: Biofilm formation inside inserted medical devices leads to their failure and acts as a source of refractory infections. The ultraviolet C (UVC) light is a potential therapy that can be used against the biofilm of bacterial pathogens.

Objective: We evaluated the efficacy of sublethal dose of UVC light with anti-staphylococcal antibiotics against biofilms made from 30 isolates of methicillin-susceptible Staphylococcus aureus and methicillin-resistant S. aureus and S. epidermidis on vascular catheters.

Materials and methods: A novel biofilm device was used to assess the combined approach. The biofilms on the catheters were irradiated with the UVC light at 254 nm and irradiance of 6.4 mW followed by treatment with vancomycin or quinupristin/dalfopristin at twice their minimum bactericidal concentrations or with linezolid at 64 µg/mL for 24 hours. The catheters were cut into segments and sonicated, and the number of the sessile cells was determined colorimetrically using XTT viable cells assay. The effect of UVC radiation followed by treatment with an antistaphylococcal antibiotic on the viability of the bacteria in the biofilm was visualized using LIVE/DEAD BacLight bacterial viability stain and confocal laser scanning microscopy.

Results: Exposure of the bacterial biofilms to the UVC light or each of the antibiotics alone was ineffective in killing the bacteria. Treatment of the biofilms with the antibiotics following their exposure to UVC light significantly (P<0.001) reduced the number of viable cells within the biofilms but did not completely eradicate them.

Conclusion: To our knowledge, this combinatorial approach has not been investigated before. The combined approach can be used as a therapeutic modality for managing biofilm-associated infections by preventing the establishment of biofilms and/or disrupting the formed biofilms on the inserted medical devices with the goal of increasing their usefulness and preventing infectious complications. Further investigations are needed to assess the effectiveness of the combined approach in the clinical settings.

No MeSH data available.


Related in: MedlinePlus

Effect of exposure to a sublethal dose of UVC light followed by treatment with twice the MBC of Q/D on the biofilms of 30 isolates of MSSA, MRSA, and S. epidermidis on the vascular catheter.Abbreviations: UVC, ultraviolet C; MBCs, minimum bactericidal concentrations; Q/D, quinupristin/dalfopristin; MSSA, methicillin-susceptible Staphylococcus aureus; MRSA, methicillin-resistant Staphylococcus aureus; S. epidermidis, Staphylococcus epidermidis; SD, standard deviation.
© Copyright Policy
Related In: Results  -  Collection

License 1 - License 2
getmorefigures.php?uid=PMC4998029&req=5

f2-idr-9-181: Effect of exposure to a sublethal dose of UVC light followed by treatment with twice the MBC of Q/D on the biofilms of 30 isolates of MSSA, MRSA, and S. epidermidis on the vascular catheter.Abbreviations: UVC, ultraviolet C; MBCs, minimum bactericidal concentrations; Q/D, quinupristin/dalfopristin; MSSA, methicillin-susceptible Staphylococcus aureus; MRSA, methicillin-resistant Staphylococcus aureus; S. epidermidis, Staphylococcus epidermidis; SD, standard deviation.

Mentions: Exposure of the biofilms to the UVC light at 254 nm for 5 minutes was ineffective in killing the bacteria. The mean percent viability of MSSA, MRSA, and S. epidermidis in the biofilms compared to controls was 94.36±6.10, 95.36±4.42, and 97.26±4.08, respectively, following exposure to the UVC light alone. Similar results were obtained when each of the antibiotics was used alone against the biofilms. Following treatment with Q/D, the mean percent viability of the bacteria in the biofilms compared to the control was 94.98±2.86, 95.07±3.99, and 88.76±6.13, respectively. Treatment of the biofilms with Q/D following the exposure to the UVC light significantly (P<0.001) reduced the number of viable cells within the biofilms. The mean percent viability of the cells compared to the control was 64.15±4.98, 67±5.07, and 62.89±6.39, respectively (Figure 2).


Efficacy of ultraviolet C light at sublethal dose in combination with antistaphylococcal antibiotics to disinfect catheter biofilms of methicillin-susceptible and methicillin-resistant Staphylococcus aureus and Staphylococcus epidermidis in vitro
Effect of exposure to a sublethal dose of UVC light followed by treatment with twice the MBC of Q/D on the biofilms of 30 isolates of MSSA, MRSA, and S. epidermidis on the vascular catheter.Abbreviations: UVC, ultraviolet C; MBCs, minimum bactericidal concentrations; Q/D, quinupristin/dalfopristin; MSSA, methicillin-susceptible Staphylococcus aureus; MRSA, methicillin-resistant Staphylococcus aureus; S. epidermidis, Staphylococcus epidermidis; SD, standard deviation.
© Copyright Policy
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4998029&req=5

f2-idr-9-181: Effect of exposure to a sublethal dose of UVC light followed by treatment with twice the MBC of Q/D on the biofilms of 30 isolates of MSSA, MRSA, and S. epidermidis on the vascular catheter.Abbreviations: UVC, ultraviolet C; MBCs, minimum bactericidal concentrations; Q/D, quinupristin/dalfopristin; MSSA, methicillin-susceptible Staphylococcus aureus; MRSA, methicillin-resistant Staphylococcus aureus; S. epidermidis, Staphylococcus epidermidis; SD, standard deviation.
Mentions: Exposure of the biofilms to the UVC light at 254 nm for 5 minutes was ineffective in killing the bacteria. The mean percent viability of MSSA, MRSA, and S. epidermidis in the biofilms compared to controls was 94.36±6.10, 95.36±4.42, and 97.26±4.08, respectively, following exposure to the UVC light alone. Similar results were obtained when each of the antibiotics was used alone against the biofilms. Following treatment with Q/D, the mean percent viability of the bacteria in the biofilms compared to the control was 94.98±2.86, 95.07±3.99, and 88.76±6.13, respectively. Treatment of the biofilms with Q/D following the exposure to the UVC light significantly (P<0.001) reduced the number of viable cells within the biofilms. The mean percent viability of the cells compared to the control was 64.15±4.98, 67±5.07, and 62.89±6.39, respectively (Figure 2).

View Article: PubMed Central - PubMed

ABSTRACT

Background: Biofilm formation inside inserted medical devices leads to their failure and acts as a source of refractory infections. The ultraviolet C (UVC) light is a potential therapy that can be used against the biofilm of bacterial pathogens.

Objective: We evaluated the efficacy of sublethal dose of UVC light with anti-staphylococcal antibiotics against biofilms made from 30 isolates of methicillin-susceptible Staphylococcus aureus and methicillin-resistant S. aureus and S. epidermidis on vascular catheters.

Materials and methods: A novel biofilm device was used to assess the combined approach. The biofilms on the catheters were irradiated with the UVC light at 254 nm and irradiance of 6.4 mW followed by treatment with vancomycin or quinupristin/dalfopristin at twice their minimum bactericidal concentrations or with linezolid at 64 &micro;g/mL for 24 hours. The catheters were cut into segments and sonicated, and the number of the sessile cells was determined colorimetrically using XTT viable cells assay. The effect of UVC radiation followed by treatment with an antistaphylococcal antibiotic on the viability of the bacteria in the biofilm was visualized using LIVE/DEAD BacLight bacterial viability stain and confocal laser scanning microscopy.

Results: Exposure of the bacterial biofilms to the UVC light or each of the antibiotics alone was ineffective in killing the bacteria. Treatment of the biofilms with the antibiotics following their exposure to UVC light significantly (P&lt;0.001) reduced the number of viable cells within the biofilms but did not completely eradicate them.

Conclusion: To our knowledge, this combinatorial approach has not been investigated before. The combined approach can be used as a therapeutic modality for managing biofilm-associated infections by preventing the establishment of biofilms and/or disrupting the formed biofilms on the inserted medical devices with the goal of increasing their usefulness and preventing infectious complications. Further investigations are needed to assess the effectiveness of the combined approach in the clinical settings.

No MeSH data available.


Related in: MedlinePlus