The pathogenic yeast Candida albicans has higher resistance than the baker's yeast Saccharomyces cerevisiae to elevated concentrations of copper. To understand the basis of this differential resistance, we performed a functional screen for C. albicans genes involved in copper detoxification. Here, we report the isolation of two such genes: a metallothionein, CaCUP1, and a copper-transporting P-type ATPase, CaCRP1. Both genes are induced by extracellular copper. Gene disruptions indicated that the copper extrusion pump is responsible for the unusual resistance of C. albicans to copper, whereas the metallothionein is responsible for the residual copper resistance of the Cacrp1⌬ mutant. We show further that under acidic and anaerobic conditions, such as prevail in the natural niche of C. albicans, the digestive tract of animals, CaCRP1 function becomes essential for survival in the presence of even very low copper concentrations. These observations suggest that copper in the gastrointestinal tract may present a toxic challenge to which enteric organisms had to adapt.copper toxicity ͉ metallothionein
The presence of Candida albicans and other Candida species in saliva and faeces of 50 psoriatic patients compared with a control group of 50 healthy donors was examined quantitatively. The quantity of Candida in saliva and faeces of the psoriatics proved to be significantly higher than in the controls. Candida was detected in 78% of the saliva samples of the psoriatics but in only 50% of the controls, and in the faeces samples in 72% of the psoriatics, but in only 46% of the controls. Qualitative analysis revealed a predominance of Candida albicans (saliva, 77%; faeces, 64%) and Candida rugosa (saliva, 28%; faeces, 28%). We did not find a correlation between the severity of the psoriasis according to the Psoriasis Area and Severity Index and the amount of Candida in the saliva or in the faeces. Our results reinforce the hypothesis that C. albicans is one of the triggers to both exacerbation and persistence of psoriasis. We propose that in psoriatics with a significant quantity of Candida in faeces, an antifungal treatment should be considered as an adjuvant treatment of psoriasis.
Adhesion of bacteria to biomaterials and the ability of many microorganisms to form biofilms on foreign bodies are well-established as major contributors to the pathogenesis of implant-associated infections. Treatment of bone infection remains problematic, due to the difficulty of systemically administered antibiotics to locally penetrate bone. The current research addresses this issue by focusing on the development and study of novel gentamicin-loaded bioresorbable films designed to serve as "coatings" for fracture fixation devices and prevent implant-associated infections. Poly(L-lactic acid) and poly (D,L-lactic-co-glycolic acid) films containing gentamicin were developed through solution processing. The effects of polymer type, drug content, and processing conditions on the drug release profile were studied with respect to film morphology. The examined films generally exhibited a burst effect followed by a moderate approximately constant rate of release. The drug contents in the surrounding medium exceeded the required minimal effective concentration. Various gentamicin concentrations that were released from the films with time exhibited efficacy against bacterial species known to be involved in orthopedic infections. The developed systems can be applied on the surface of any metallic or polymeric fracture fixation device, and may therefore comprise a significant contribution to the field of orthopedic implants.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.