| Popis: |
This chapter emphasizes the underlying mechanisms that govern the physical and chemical interactions between organisms and their potential relevance to disease. Many biofilms within the host are not simply single species assemblages, but rather, dynamic polymicrobial communities. Candida spp. in biofilms on medical devices are most often derived from the host’s own endogenous flora, and other microflora organisms, such as staphylococci, are also often associated with catheters in both the presence and absence of Candida albicans. Direct consequences of mixed infections could include C. albicans enhancement of Pseudomonas aeruginosa biofilm formation, antibiotic resistance or virulence factor production, or changes in immune responses or host tissues that result from simultaneous infection by bacteria and fungi. While C. albicans frequently encounters large numbers of gram-positive bacteria in the oral, intestinal, and skin microfloras, a relatively small number of studies describe the molecular interactions that occur between C. albicans and gram-positive microbes. A series of clinical trials have investigated the use of probiotics for the management of recurrent vulvovaginal candidiasis, and while the data are in conclusive, further in vitro and animal studies are warranted. Unicellular organisms often produce small, diffusible chemical signals, referred to as quorum-sensing molecules (QSMs), that coordinate group behavior within single-species populations. |
