Candida albicans forms biofilms on the vaginal mucosa

“Significant attention has been given to Candida biofilm formation of indwelling catheters, which can lead to life-threatening systemic infections (Crump & Collignon, 2000; Dominic et al., 2007; Kojic & Darouiche, 2004).”

“Second, in vivo vaginal tissue 3640 Microbiology 156 contains many secretions, composed of electrolytes, organic acids and proteins, which maintain properties such as pH and osmolarity (Owen & Katz, 1999).”

“Although several Candida species have been implicated in VVC and RVVC, Candida albicans is the predominant aetiological agent, causing 85– 95 % of these infections (Sobel et al., 1998).”

“Our results are also consistent with the kinetics of in vitro biofilms grown on silicone discs, which show steady increases in dry weight measurements until 36–48 h and then remain stationary (Chandra et al., 2001; Hawser & Douglas, 1994).”

“EFG1 encodes a transcriptional factor that is required for morphogenesis under most hypha-inducing conditions in vitro (Lo et al., 1997; Stoldt et al., 1997).”

“Candida biofilms have been studied primarily on abiotic surfaces (reviewed by Blankenship & Mitchell, 2006; Ramage et al., 2006).”

“At 72 h, yeast forms (CM) were evident at the apical surface of the biofilm in conjunction with the residential hyphae, which coincided with the predicted dispersal phase of biofilm growth (Blankenship & Mitchell, 2006).”

“…biofilm formation, i.e. ECM production and hyphal growth. http://mic.sgmjournals.org 3641 BCR1 encodes a transcriptional regulator that is required for production of vigorous biofilms on abiotic surfaces in vitro and in vivo in a catheter model (Nobile et al., 2006a; Nobile & Mitchell, 2005).”

“ConA is a lectin that binds to C. albicans polysaccharides secreted as part of the matrix. b-Glucan is a cell wall polysaccharide that has been detected in Candida ECM by a Limulus amoebocyte lysate clotting enzyme based assay (Nett et al., 2007a, b).”

“3153A Wild-type Slutsky et al. (1985)”

“…biofilm formation, i.e. ECM production and hyphal growth. http://mic.sgmjournals.org 3641 BCR1 encodes a transcriptional regulator that is required for production of vigorous biofilms on abiotic surfaces in vitro and in vivo in a catheter model (Nobile et al., 2006a; Nobile & Mitchell, 2005).”

“These data show for the first time that C. albicans forms biofilms in vivo on vaginal epithelium, and that in vivo biotic biofilm formation requires regulators of biofilm formation (BCR1) and morphogenesis (EFG1).”

“Prior to this study, the only in vivo vaginal biofilm characterized was bacterial, consisting of Gardnerella vaginalis (Scott et al., 1989; Swidsinski et al., 2008; van der Meijden et al., 1988).”

“These mutants have previously been shown to form poor or no biofilms on abiotic surfaces (Nobile et al., 2006a, b; Nobile & Mitchell, 2005; Ramage et al., 2002).”

“%) experience recurrent vulvovaginal candidiasis (RVVC), defined as having three or more episodes per year (Sobel, 1992).”

“In resistant women, vaginal epithelial cells are important for protection against infection (Fidel et al., 2004).”

“Significant attention has been given to Candida biofilm formation of indwelling catheters, which can lead to life-threatening systemic infections (Crump & Collignon, 2000; Dominic et al., 2007; Kojic & Darouiche, 2004).”

“albicans was shown to form biofilms on oral mucosa in an immunosuppressed murine model of oropharyngeal candidiasis (Dongari-Bagtzoglou et al., 2009).”

“Higher inocula were used for DAY185 and mutants because initial experiments demonstrated that 3153A colonizes mucosal tissue better than DAY185 and biofilm mutants, as previously reported (Naglik et al., 2008; Taylor et al., 2000).”

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“ConA is a lectin that binds to C. albicans polysaccharides secreted as part of the matrix. b-Glucan is a cell wall polysaccharide that has been detected in Candida ECM by a Limulus amoebocyte lysate clotting enzyme based assay (Nett et al., 2007a, b).”

“C. albicans strains included 3153A (lab strain), DAY185 (parental control strain), and mutants defective in morphogenesis and/or biofilm formation in vitro (efg1/ efg1 and bcr1/bcr1).”

“Finally, with C. albicans rarely exhibiting resistance to azoles during VVC (Bauters et al., 2002; Mathema et al., 2001), how does this relate to the high rates of biofilm resistance on abiotic surfaces?”

“Accordingly, the efg1/efg1 mutant is unable to form biofilms in vitro in RPMI or YNB+glucose; however, its biofilm formation ability in vivo has not been previously reported (Ramage et al., 2002; Watamoto et al., 2009).”

“Higher inocula were used for DAY185 and mutants because initial experiments demonstrated that 3153A colonizes mucosal tissue better than DAY185 and biofilm mutants, as previously reported (Naglik et al., 2008; Taylor et al., 2000).”

“Prior to this study, the only in vivo vaginal biofilm characterized was bacterial, consisting of Gardnerella vaginalis (Scott et al., 1989; Swidsinski et al., 2008; van der Meijden et al., 1988).”

“Prior to this study, the only in vivo vaginal biofilm characterized was bacterial, consisting of Gardnerella vaginalis (Scott et al., 1989; Swidsinski et al., 2008; van der Meijden et al., 1988).”

“Most infections result from pathogenic biofilms; therefore, the biomedical significance of biofilms is substantial (Ganguly & Mitchell, 2011; Harriott et al., 2010).”

“albicans in 166 tissue culture plates) also show similar biofilm architectures with yeast cells, hyphae, 167 and extracellular matrix evident throughout the biofilms, formed on top of mucosal 168 layers [18].”

“Biofilms allow the cells to adhere to and proliferate onmedically implanted devices as well as host tissue, causing infections [10,18,19].”

“albicans produces dense three-dimensional biofilms that are embedded in extracellular matrix materia”