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Distribution and Inhibition of Liposomes on Staphylococcus aureus and Pseudomonas aeruginosa Biofilm.

Dong D, Thomas N, Thierry B, Vreugde S, Prestidge CA, Wormald PJ - PLoS ONE (2015)

Bottom Line: Staphylococcus aureus and Pseudomonas aeruginosa are major pathogens in chronic rhinosinusitis (CRS) and their biofilms have been associated with poorer postsurgical outcomes.Biofilm growth was inhibited at 24-hour and five-minute exposure time, although the decrease of viability for P. aeruginosa biofilm after liposomal treatment did not reach statistical significance.The distribution and anti-biofilm effects of cationic and anionic liposomes of different sizes differed in S. aureus and P. aeruginosa biofilms.

View Article: PubMed Central - PubMed

Affiliation: Department of Surgery- Otorhinolaryngology Head and Neck Surgery, The Queen Elizabeth Hospital, and the University of Adelaide, Adelaide, South Australia; The Rhinology Department, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, China.

ABSTRACT

Background: Staphylococcus aureus and Pseudomonas aeruginosa are major pathogens in chronic rhinosinusitis (CRS) and their biofilms have been associated with poorer postsurgical outcomes. This study investigated the distribution and anti-biofilm effect of cationic (+) and anionic (-) phospholipid liposomes with different sizes (unilamellar and multilamellar vesicle, ULV and MLV respectively) on S. aureus and P. aeruginosa biofilms.

Method: Specific biofilm models for S. aureus ATCC 25923 and P. aeruginosa ATCC 15692 were established. Liposomal distribution was determined by observing SYTO9 stained biofilm exposed to DiI labeled liposomes using confocal scanning laser microscopy, followed by quantitative image analysis. The anti-biofilm efficacy study was carried out by using the alamarBlue assay to test the relative viability of biofilm treated with various liposomes for 24 hours and five minutes.

Results: The smaller ULVs penetrated better than larger MLVs in both S. aureus and P. aeruginosa biofilm. Except that +ULV and -ULV displayed similar distribution in S. aureus biofilm, the cationic liposomes adhered better than their anionic counterparts. Biofilm growth was inhibited at 24-hour and five-minute exposure time, although the decrease of viability for P. aeruginosa biofilm after liposomal treatment did not reach statistical significance.

Conclusion: The distribution and anti-biofilm effects of cationic and anionic liposomes of different sizes differed in S. aureus and P. aeruginosa biofilms. Reducing the liposome size and formulating liposomes as positively charged enhanced the penetration and inhibition of S. aureus and P. aeruginosa biofilms.

No MeSH data available.


Related in: MedlinePlus

Liposomal distribution in S. aureus biofilm.The y-axis represents the integrated fluorescent density of the red channel (liposomes) normalized by that of the green channel (biofilm), reflecting the amount of liposomes per unit of biomass in each layer of the biofilm. The x-axis indicates the z-position of the layers in biofilm, where the location of the top surface of biofilm was assigned as zero. +MLV: cationic multilamellar vesicle; +ULV: cationic unilamellar vesicle;-MLV: anionic multilamellar vesicle;-ULV: anionic unilamellar vesicle.
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pone.0131806.g003: Liposomal distribution in S. aureus biofilm.The y-axis represents the integrated fluorescent density of the red channel (liposomes) normalized by that of the green channel (biofilm), reflecting the amount of liposomes per unit of biomass in each layer of the biofilm. The x-axis indicates the z-position of the layers in biofilm, where the location of the top surface of biofilm was assigned as zero. +MLV: cationic multilamellar vesicle; +ULV: cationic unilamellar vesicle;-MLV: anionic multilamellar vesicle;-ULV: anionic unilamellar vesicle.

Mentions: In order to make a quantitative comparison for the distribution of the four different liposomes in the biofilms, the integrated fluorescent density of every single layer in each z-stack was measured separately for the red and green channel. The integrated fluorescent density of the red channel was normalized by that of the green channel, as shown in Fig 3 and Fig 4, reflecting the distribution of liposomes per unit of biomass in each layer from the surface to the base of the biofilm. The mean thickness of S. aureus biofilm was 12μm while that of P. aeruginosa biofilm was 6.5μm in the present study, so the normalized integrated fluorescent density of the red channel was calculated on 24 and 13 layers in total to demonstrate the liposomal distribution in the entire z-stack for S. aureus and P. aeruginosa biofilm respectively. It was clear that for both S. aureus and P. aeruginosa biofilm,–MLV did not associate strongly with the body of the biofilms, and that +MLV was mainly found in the upper part of the biofilm structure. The distributions of ULVs in S. aureus biofilm were similar to each other. However, +ULV displayed higher normalized fluorescent density in the whole z-stack of P. aeruginosa biofilm than–ULV.


Distribution and Inhibition of Liposomes on Staphylococcus aureus and Pseudomonas aeruginosa Biofilm.

Dong D, Thomas N, Thierry B, Vreugde S, Prestidge CA, Wormald PJ - PLoS ONE (2015)

Liposomal distribution in S. aureus biofilm.The y-axis represents the integrated fluorescent density of the red channel (liposomes) normalized by that of the green channel (biofilm), reflecting the amount of liposomes per unit of biomass in each layer of the biofilm. The x-axis indicates the z-position of the layers in biofilm, where the location of the top surface of biofilm was assigned as zero. +MLV: cationic multilamellar vesicle; +ULV: cationic unilamellar vesicle;-MLV: anionic multilamellar vesicle;-ULV: anionic unilamellar vesicle.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4488362&req=5

pone.0131806.g003: Liposomal distribution in S. aureus biofilm.The y-axis represents the integrated fluorescent density of the red channel (liposomes) normalized by that of the green channel (biofilm), reflecting the amount of liposomes per unit of biomass in each layer of the biofilm. The x-axis indicates the z-position of the layers in biofilm, where the location of the top surface of biofilm was assigned as zero. +MLV: cationic multilamellar vesicle; +ULV: cationic unilamellar vesicle;-MLV: anionic multilamellar vesicle;-ULV: anionic unilamellar vesicle.
Mentions: In order to make a quantitative comparison for the distribution of the four different liposomes in the biofilms, the integrated fluorescent density of every single layer in each z-stack was measured separately for the red and green channel. The integrated fluorescent density of the red channel was normalized by that of the green channel, as shown in Fig 3 and Fig 4, reflecting the distribution of liposomes per unit of biomass in each layer from the surface to the base of the biofilm. The mean thickness of S. aureus biofilm was 12μm while that of P. aeruginosa biofilm was 6.5μm in the present study, so the normalized integrated fluorescent density of the red channel was calculated on 24 and 13 layers in total to demonstrate the liposomal distribution in the entire z-stack for S. aureus and P. aeruginosa biofilm respectively. It was clear that for both S. aureus and P. aeruginosa biofilm,–MLV did not associate strongly with the body of the biofilms, and that +MLV was mainly found in the upper part of the biofilm structure. The distributions of ULVs in S. aureus biofilm were similar to each other. However, +ULV displayed higher normalized fluorescent density in the whole z-stack of P. aeruginosa biofilm than–ULV.

Bottom Line: Staphylococcus aureus and Pseudomonas aeruginosa are major pathogens in chronic rhinosinusitis (CRS) and their biofilms have been associated with poorer postsurgical outcomes.Biofilm growth was inhibited at 24-hour and five-minute exposure time, although the decrease of viability for P. aeruginosa biofilm after liposomal treatment did not reach statistical significance.The distribution and anti-biofilm effects of cationic and anionic liposomes of different sizes differed in S. aureus and P. aeruginosa biofilms.

View Article: PubMed Central - PubMed

Affiliation: Department of Surgery- Otorhinolaryngology Head and Neck Surgery, The Queen Elizabeth Hospital, and the University of Adelaide, Adelaide, South Australia; The Rhinology Department, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, China.

ABSTRACT

Background: Staphylococcus aureus and Pseudomonas aeruginosa are major pathogens in chronic rhinosinusitis (CRS) and their biofilms have been associated with poorer postsurgical outcomes. This study investigated the distribution and anti-biofilm effect of cationic (+) and anionic (-) phospholipid liposomes with different sizes (unilamellar and multilamellar vesicle, ULV and MLV respectively) on S. aureus and P. aeruginosa biofilms.

Method: Specific biofilm models for S. aureus ATCC 25923 and P. aeruginosa ATCC 15692 were established. Liposomal distribution was determined by observing SYTO9 stained biofilm exposed to DiI labeled liposomes using confocal scanning laser microscopy, followed by quantitative image analysis. The anti-biofilm efficacy study was carried out by using the alamarBlue assay to test the relative viability of biofilm treated with various liposomes for 24 hours and five minutes.

Results: The smaller ULVs penetrated better than larger MLVs in both S. aureus and P. aeruginosa biofilm. Except that +ULV and -ULV displayed similar distribution in S. aureus biofilm, the cationic liposomes adhered better than their anionic counterparts. Biofilm growth was inhibited at 24-hour and five-minute exposure time, although the decrease of viability for P. aeruginosa biofilm after liposomal treatment did not reach statistical significance.

Conclusion: The distribution and anti-biofilm effects of cationic and anionic liposomes of different sizes differed in S. aureus and P. aeruginosa biofilms. Reducing the liposome size and formulating liposomes as positively charged enhanced the penetration and inhibition of S. aureus and P. aeruginosa biofilms.

No MeSH data available.


Related in: MedlinePlus