
Full text loading...
Category: Clinical Microbiology
Interactions between Candida Species and Bacteria in Mixed Infections, Page 1 of 2
< Previous page | Next page > /docserver/preview/fulltext/10.1128/9781555817947/9781555812447_Chap18-1.gif /docserver/preview/fulltext/10.1128/9781555817947/9781555812447_Chap18-2.gifAbstract:
Candida albicans is an opportunistic fungal pathogen found as part of the normal microflora in the human digestive tract. This chapter considers the etiology and pathology of some disease conditions that arise from, or involve directly, Candida interactions with bacteria. The clinical manifestations, and processes of adhesion and biofilm formation, are described for mixed-species infections, in particular those involving colonization of oral tissues and dental or medical prostheses by mixed communities of Candida and bacteria. Knowledge gained from studies of microbial colonization mechanisms in the laboratory and in vivo, and of disease mechanisms from model systems, should assist in the development of more effective methods for controlling or preventing Candida infections. The interactions between Candida and bacteria are especially important in the establishment of oral microbial communities and in the etiology of candidiasis. There are few other examples of cooperative interactions between bacteria and unicellular eukaryotic microorganisms. Adhesion processes are the defining events in establishing these polymicrobial biofilms. As the physiological and molecular processes that occur during biofilm formation are studied in greater detail, it is becoming apparent that organisms within biofilms acquire properties that are quite different from those of their free-living counterparts.
Full text loading...
Diagrammatic representation of positioning of partially implanted silicone rubber voice prosthesis (arrow). Diagram kindly provided by G. J. Elving.
Diagrammatic representation of positioning of partially implanted silicone rubber voice prosthesis (arrow). Diagram kindly provided by G. J. Elving.
Candida multiple interactions with oral surfaces, salivary components, host components and bacteria in oral biofilms. Interactions designated A through E are as follows: A, adhesion of C. albicans to the surfaces of teeth or prostheses coated with an acquired pellicle of salivary proteins and glycoproteins or to epithelial cells or bacteria via adsorbed salivary components (different salivary components may be adsorbed to the different surfaces); B, adhesion of C. albicans to the surfaces of prostheses or epithelial cells via adsorbed or attached tissue matrix proteins; C, adhesion of C. albicans to bacteria via protein-carbohydrate and protein-protein reactions; D, adhesion of C. albicans to epithelial cell receptors; E, physicochemical interaction of yeast cells with unmodified tooth enamel or prosthetic material.
Candida multiple interactions with oral surfaces, salivary components, host components and bacteria in oral biofilms. Interactions designated A through E are as follows: A, adhesion of C. albicans to the surfaces of teeth or prostheses coated with an acquired pellicle of salivary proteins and glycoproteins or to epithelial cells or bacteria via adsorbed salivary components (different salivary components may be adsorbed to the different surfaces); B, adhesion of C. albicans to the surfaces of prostheses or epithelial cells via adsorbed or attached tissue matrix proteins; C, adhesion of C. albicans to bacteria via protein-carbohydrate and protein-protein reactions; D, adhesion of C. albicans to epithelial cell receptors; E, physicochemical interaction of yeast cells with unmodified tooth enamel or prosthetic material.
Coaggregation and coadhesion of C. albicans and oral streptococci. (A) Coaggregation of C. albicans in suspension with Streptococcus gordonii. (B) Adhesion of C. albicans cells to S. gordonii cells immobilized onto polystyrene. Bars, 5 μm. Reproduced with permission from reference 29 .
Coaggregation and coadhesion of C. albicans and oral streptococci. (A) Coaggregation of C. albicans in suspension with Streptococcus gordonii. (B) Adhesion of C. albicans cells to S. gordonii cells immobilized onto polystyrene. Bars, 5 μm. Reproduced with permission from reference 29 .
Intergeneric coaggregation reactions and coadhesion of Candida with oral bacteria in mixed-species biofilms. Interactions between Candida, Streptococcus, Actinomyces, and Fusobacterium involve multiple adhesin-receptor reactions and promote retention of these organisms in defined relationships within oral biofilms. The abilities of P. gingivalis and T. denticola to bind streptococci and fusobacteria contribute to their success as secondary colonizers, especially within subgingival communities.
Intergeneric coaggregation reactions and coadhesion of Candida with oral bacteria in mixed-species biofilms. Interactions between Candida, Streptococcus, Actinomyces, and Fusobacterium involve multiple adhesin-receptor reactions and promote retention of these organisms in defined relationships within oral biofilms. The abilities of P. gingivalis and T. denticola to bind streptococci and fusobacteria contribute to their success as secondary colonizers, especially within subgingival communities.
C. albicans and mixed-species biofilms formed in vitro. (A) C. albicans biofilm showing bilayer structure of germ-tube-forming cells and hyphae growing above layers of yeast cells (blastospores). (B) Mixed-species biofilm of C. albicans (yeast and hyphal forms) and S. gordonii (smaller cocci with individual cells and clusters adhering predominantly to blastospores). (C) Mixed-species biofilm of C. albicans (mainly hyphal forms) and Streptococcus salivarius. Bars, 10 μm.
C. albicans and mixed-species biofilms formed in vitro. (A) C. albicans biofilm showing bilayer structure of germ-tube-forming cells and hyphae growing above layers of yeast cells (blastospores). (B) Mixed-species biofilm of C. albicans (yeast and hyphal forms) and S. gordonii (smaller cocci with individual cells and clusters adhering predominantly to blastospores). (C) Mixed-species biofilm of C. albicans (mainly hyphal forms) and Streptococcus salivarius. Bars, 10 μm.
The critical effect of perturbation of host environmental conditions in the shift from commensal to pathogenic microflora. Candida cells (black) are present in low numbers within the oral microflora or are acquired from other individuals. A major disruption of the host physiology, e.g., reduced salivary flow or immune cell function, or of bacterial flora, e.g., following antibiotic treatment, provides conditions for Candida to outcompete the numerically dominant members of the microflora and cause disease.
The critical effect of perturbation of host environmental conditions in the shift from commensal to pathogenic microflora. Candida cells (black) are present in low numbers within the oral microflora or are acquired from other individuals. A major disruption of the host physiology, e.g., reduced salivary flow or immune cell function, or of bacterial flora, e.g., following antibiotic treatment, provides conditions for Candida to outcompete the numerically dominant members of the microflora and cause disease.