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In yeast, external signals such as high osmolarity or oxidant conditions activate the high osmolarity glycerol (HOG) mitogen-activated protein kinase (MAPK) cascade pathway, which consists of two upstream branches, i.e. Sho1p and Sln1p and common downstream elements, including the Pbs2p MAPK kinase and the Hog1p MAPK. We recently showed that the Candida lusitaniae SLN1 gene, potentially encoding a histidine kinase receptor, is crucial for oxidative stress adaptation when the fungus grows as budding yeast and during the early steps of pseudohyphal development. In the current study, we characterized the SHO1 gene of this opportunistic fungus. Complete loss of SHO1 function causes profound defects in pseudohyphal differentiation, especially in high osmolarity and oxidative stress conditions, suggesting a crucial role of SHO1 in the pseudohyphae morphogenetic transitions. Moreover, when grown as budding yeast, the sho1Δ mutant revealed a sensitivity to compounds that interfere with the cell wall assembly, pointing to a potential role of Sho1p in cell wall biogenesis. However, the sho1Δ mutant does not display evident cell-wall architecture modifications, such as aggregation phenotypes. Although not hypersusceptible to antifungals of clinical relevance, the sho1Δ mutants are susceptible to the filamentous fungi-specific antifungals dicarboximides and phenylpyrroles. Finally, our findings highlight some significant phenotypic differences when the C. lusitaniae sho1Δ mutant is compared with the corresponding mutants described in Saccharomyces cerevisiae, Candida albicans and Aspergillus fumigatus. The GeneBank Accession No. for C. lusitaniae SHO1 gene is EU797514. Copyright © 2008 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Inactivation of the FCY2 (cytosine permease), FCY1 (cytosine deaminase), and FUR1 (uracil phosphoribosyltransferase) genes in Candida lusitaniae produced two patterns of resistance to flucytosine. Mutant fur1 demonstrated resistance to 5-fluorouracil, whereas mutants fcy1 and fcy2 demonstrated fluconazole resistance in the presence of subinhibitory flucytosine concentrations.

Background & Objectives: A limited number of biotypes, T-types, and emm-types have been found to be associated with invasive isolates of group A streptococci, confirming the involvement of the M protein in virulence and its importance as an epidemiological marker. In this study, the epidemiological markers in the clinical isolates of group A streptococci were compared in invasive and non invasive isolates., Methods: From 1998 to 2001, 141 invasive and 353 non invasive isolates in France were studied and their biotype, T-type, and emm-type were determined., Results: The invasive isolates were mostly obtained from blood whereas the non invasive isolates were isolated from throat. Most of the isolates were of biotype 1. The invasive isolates were mostly of the T-type 1 associated with emm-type 1. The T-type 4 associated with emm-type 4 and the T-type 28 associated with emm-type 28 were also frequent. Invasive isolates responsible for puerperal sepsis and non invasive isolates were mostly of the T-type 28 associated with emm-type 28., Interpretation & Conclusion: This study confirms the high prevalence of isolates of biotype 1, T-type 1, and emm-type 1 among invasive isolates of group A streptococci. The emm-type 28 associated with T-type 28 was frequently observed in non-invasive isolates. A prospective study is being conducted to update the prevalence of the different emm-types in France, which will be of importance for the development of future vaccines.