Antimicrobial Coatings to Prevent Biofilm Formation on Medical Devices - Antibiofilm Agents: From Diagnosis to Treatment and Prevention - page 178

the catheter surface (Stickler et al. 2003 ; Jones et al. 2005 ). In addition, the
reduction in bacterial activity would prevent the increase in the urinary pH (Stickler
et al. 2003 ; Jones et al. 2005 ). Analysis of Proteus mirabilis biofilm development
using this model showed that in comparison with a control catheter, a latex catheter
inflated with triclosan had a controlled urinary pH, reduced the number of bacteria
in urine, and showed no surge of encrustation (Williams and Stickler 2008 ).
However, different results were obtained when the model was utilized to determine
if triclosan prevented encrustation by microflora of uropathogens that commonly
infect patients undergoing long-term catheterization (Williams and Stickler 2008 ).
While Proteus mirabilis , Escherichia coli , and Klebsiella pneumoniae were elim-
inated from the residual urine, there was no effect on Enterococcus faecalis and
Pseudomonas aeruginosa (Williams and Stickler 2008 ).
3.2.4 Gendine and Nitric Oxide
Hachem et al. described Gendine as a novel antimicrobial catheter coating (Hachem
et al. 2009 ). In comparison with uncoated and silver hydrogel-coated catheters,
Gendine-coated catheters significantly reduced biofilm produced by different path-
ogens including Pseudomonas aeruginosa , Enterococcus faecalis , Klebsiella
pneumoniae , and Candida (Hachem et al. 2009 ). Gendine-coated catheters were
more efficient than silver hydrogel-coated ones in preventing Escherichia coli
colonization in a rabbit model (Hachem et al. 2009 ).
Regev-Shoshani et al. impregnated Foley urinary catheters with nitric oxide
(NO) (Regev-Shoshani et al. 2010 ). NO, which is a small naturally produced,
hydrophobic, free radical gas, is bacteriostatic and bacteriocidal (Fang 1997 ;
McMullin et al. 2005 ). Coated catheters slowly released NO over 14 days and
prevented bacterial colonization and biofilm formation on the luminal and exterior
surfaces of the catheters (Regev-Shoshani et al. 2010 ).
3.2.5 Antibiotics
Antibiotic-coated urethral catheters have also been developed. Norfloxacin, a
fluroquinolone synthetic antibiotic, was impregnated into a coating layer on the
outer and inner surfaces of a urethral catheter (Park et al. 2003 ). Norfloxacin-coated
catheters generated a considerable zone of inhibition against Escherichia coli,
Klebsiella pneumoniae, and Proteus vulgaris for 6 days (Park et al. 2003 ). A similar
approach was used to generate gentamicin-coated catheters (Cho et al. 2003 ).
Kowalczuk et al. (Kowalczuk et al. 2012 ) described covalent and non-covalent
attachment of sparfloxacin to the surface of heparin-coated urinary catheters. The
catheters prevented colonization and biofilm development of Escherichia coli ,
Staphylococcus aureus , and Staphylococcus epidermidis for about 3 days
(Kowalczuk et al. 2012 ), and inhibition assays confirmed their antimicrobial activ-
ity (Kowalczuk et al. 2012 ). Pugach et al. ( 1999 ) described silicon Foley catheters