High-frequency switching in Candida strains isolated from vaginitis patients

Abstract

High-frequency switching and strain variability at the site of infection was assessed in Il patients with acute Candida albicans vaginitis. By cloning cells directly from the site of infection, it was demonstrated that 4 of the 11 isolates contained multiple-switch phenotypes at the site of infection and that 9 of the 11 isolates were in a high-frequency mode of switching (10-2 to 10-3). Isolates could be separated into four general categories of switching repertoires. To demonstrate that multiple phenotypes at the site of a single infection represented the same strain, EcoRI digests of total cell DNA were separated on agarose gels, and Southern hybridization patterns with two cloned midrepeat sequences were compared. Candida albicans remains the most persistent and pervasive yeast pathogen in humans, capable of invading virtually every tissue of the body (2, 11). Not only is it the major cause of vaginal and oral yeast infections (6, 7, 9, 16, 17, 20), but it has evolved into a major systemic pathogen of compromised hosts (2, 3, 5, 10, 12). Recently, it was demonstrated that a common laboratory strain of C. albicans possesses a high-frequency switching system which can be distinguished by colony morphology on the proper agar substratum (14). Cells of this strain switch spontaneously to six general colony phenotypes at a combined frequency of ' The opaque sector (OS) and white sector (WS) were individually cloned.

Frequency and expression of ALS and HWP1 genotypes in Candida albicans strains isolated from Mexican patients suffering from vaginal candidosis

“…These include pregnancy, use of oral contraceptives or antibiotics and diabetes mellitus. 3,5 Candida albicans has several virulence factors, including hyphal formation, 6 phenotypic switching, [7][8][9] secretion of hydrolytic enzymes 10,11 and adhesion to epithelial cells. Members of the ALS gene family encode cell-wall glycoproteins, some of which are implicated in the adhesion to host surfaces.…”

Effect of licorice compounds licochalcone A, glabridin and glycyrrhizic acid on growth and virulence properties of Candida albicans

“…8 Many studies have shown a much higher frequency of hyphae phenotype of C. albicans in infected sites. 1,6,9 Biofilms, which are heterogeneous communities of microorganisms growing on a solid substrate, are formed by C. albicans. 10 Candida albicans organised in biofilms has been reported to be up to 1000 times more resistant to antifungal drugs compared with their planktonic form.…”

The role of pH in salivary histidine‐rich polypeptide antifungal germ tube inhibitory activity

“…Both the blastospore and germ tube forms of C. albicans (7,18), as well as other morphological forms of C albicans (25), are likely to be virulent if this organism gains more than its carrier status foothold inside its ecological niche. The germ tube form has, in addition, been shown to enhance the virulence of the organism in vaginal candidiasis animal model systems (24) and might be expected to play a similar role in oral candidiasis.…”