Candida albicans is usually a harmless human commensal. Because inflammatory responses are not normally induced by colonization, antimicrobial peptides are likely integral to first-line host defense against invasive candidiasis. Thus, C. albicans must have mechanisms to tolerate or circumvent molecular effectors of innate immunity and thereby colonize human tissues. Prior studies demonstrated that an antimicrobial peptide-resistant strain of C. albicans, 36082R, is hypervirulent in animal models versus its susceptible counterpart (36082S). The current study aimed to identify a genetic basis for antimicrobial peptide resistance in C. albicans. Screening of a C. albicans genomic library identified SSD1 as capable of conferring peptide resistance to a susceptible surrogate, Saccharomyces cerevisiae. Sequencing confirmed that the predicted translation products of 36082S and 36082R SSD1 genes were identical. However, Northern analyses corroborated that SSD1 is expressed at higher levels in 36082R than in 36082S. In isogenic backgrounds, ssd1/ssd1 null mutants were significantly more susceptible to antimicrobial peptides than parental strains but had equivalent susceptibilities to nonpeptide stressors. Moreover, SSD1 complementation of ssd1/ssd1 mutants restored parental antimicrobial peptide resistance phenotypes, and overexpression of SSD1 conferred enhanced peptide resistance. Consistent with these in vitro findings, ssd1 null mutants were significantly less virulent in a murine model of disseminated candidiasis than were their parental or complemented strains. Collectively, these results indicate that SSD1 is integral to C. albicans resistance to host defense peptides, a phenotype that appears to enhance the virulence of this organism in vivo.
- American Society for Microbiology
- Ssd1 is integral to host defense peptide resistance in candida ...
Using Resistivity for Basalt Site Characterization - Case Study
Purpose A mining company in Turkey hoped to determine existing and new alternative basalt zones at an existing basalt mining site by using Electrical Resistivity Imaging (ERI). Process Our client, Ali Karan, used 84 electrodes spaced at 10 meters and two lines 5 meters apart inside the study area. The dipole-gradient array was used to collect the 2D electrical resistivity imaging data set. Results Resistivity imaging mapped the vertical and lateral limits of basalt zones successfully. The ground truth was...
2D Resistivity Imaging for Locating Concrete Pipe - Case Study
Background There are 8 wells that suply water to the communnity through about 2m diamter concrete aqueduct. Purpose The main subject of the field tes was to determine the geotechnical site characterization of the area to correlate the results obtained through the 2D resistivity imaging and the infromation of the concrete aqueduct. Process The determination of site characterization was performed by AGI SuperSting Wi-Fi R8/IP/SP instrument with 42 electrodes and 3 meters electrode spacing with a mixed array...
A history of chemically resistant membranes
The use of polymeric membranes for filtration of non-aqueous solutions started around 1960 and has been developed significantly since then . Today, non-aqueous membrane filtration applications in chemical and pharmaceutical processing account for more than 25% of the global total polymeric membrane market .To put into perspective the potential significance of membrane filtration for non-aqueous solutions, one must realize that conventional separation processes still accounts for up to 70% of capital (CAPEX)...
Towards a research agenda for water, sanitation and antimicrobial resistance
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Advantages of Corrosion Resistant Lighting in Offshore Helidecks
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