Preventing Pseudomonas aeruginosa Biofilms on Indwelling Catheters by Surface-Bound Enzymes

Author(s):  
Dalal Asker ◽  
Tarek S. Awad ◽  
Deepa Raju ◽  
Hiram Sanchez ◽  
Ira Lacdao ◽  
...  
2014 ◽  
Vol 82 (5) ◽  
pp. 2048-2058 ◽  
Author(s):  
Stephanie J. Cole ◽  
Angela R. Records ◽  
Mona W. Orr ◽  
Sara B. Linden ◽  
Vincent T. Lee

ABSTRACTPseudomonas aeruginosais an opportunistic human pathogen that is especially adept at forming surface-associated biofilms.P. aeruginosacauses catheter-associated urinary tract infections (CAUTIs) through biofilm formation on the surface of indwelling catheters.P. aeruginosaencodes three extracellular polysaccharides, PEL, PSL, and alginate, and utilizes the PEL and PSL polysaccharides to form biofilmsin vitro; however, the requirement of these polysaccharides duringin vivoinfections is not well understood. Here we show in a murine model of CAUTI that PAO1, a strain harboringpel,psl, andalggenes, and PA14, a strain harboringpelandalggenes, form biofilms on the implanted catheters. To determine the requirement of exopolysaccharide duringin vivobiofilm infections, we tested isogenic mutants lacking thepel,psl, andalgoperons and showed that PA14 mutants lacking these operons can successfully form biofilms on catheters in the CAUTI model. To determine the host factor(s) that induces the ΔpelDmutant to form biofilm, we tested mouse, human, and artificial urine and show that urine can induce biofilm formation by the PA14 ΔpelDmutant. By testing the major constituents of urine, we show that urea can induce apel-,psl-, andalg-independent biofilm. Thesepel-,psl-, andalg-independent biofilms are mediated by the release of extracellular DNA. Treatment of biofilms formed in urea with DNase I reduced the biofilm, indicating that extracellular DNA supports biofilm formation. Our results indicate that the opportunistic pathogenP. aeruginosautilizes a distinct program to form biofilms that are independent of exopolysaccharides during CAUTI.


Author(s):  
M.A. Gregory ◽  
G.P. Hadley

The insertion of implanted venous access systems for children undergoing prolonged courses of chemotherapy has become a common procedure in pediatric surgical oncology. While not permanently implanted, the devices are expected to remain functional until cure of the primary disease is assured. Despite careful patient selection and standardised insertion and access techniques, some devices fail. The most commonly encountered problems are colonisation of the device with bacteria and catheter occlusion. Both of these difficulties relate to the development of a biofilm within the port and catheter. The morphology and evolution of biofilms in indwelling vascular catheters is the subject of ongoing investigation. To date, however, such investigations have been confined to the examination of fragments of biofilm scraped or sonicated from sections of catheter. This report describes a novel method for the extraction of intact biofilms from indwelling catheters.15 children with Wilm’s tumour and who had received venous implants were studied. Catheters were removed because of infection (n=6) or electively at the end of chemotherapy.


Pneumologie ◽  
2010 ◽  
Vol 64 (01) ◽  
Author(s):  
L Sprenger ◽  
T Goldmann ◽  
E Vollmer ◽  
B Wollenberg ◽  
P Zabel ◽  
...  

Pneumologie ◽  
2010 ◽  
Vol 64 (S 03) ◽  
Author(s):  
L Spenger ◽  
T Goldmann ◽  
E Vollmer ◽  
B Wollenberg ◽  
HP Hauber ◽  
...  

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