microorganisms Review Candida and Candidiasis—Opportunism Versus Pathogenicity: A Review of the Virulence Traits Cristina Nicoleta Ciurea 1,2,* , Irina-Bianca Kosovski 2,3, Anca Delia Mare 1, Felicia Toma 1, Ionela Anca Pintea-Simon 1,2 and Adrian Man 1 1 Department of Microbiology, George Emil Palade University of Medicine, Pharmacy, Science, and Technology of Târgu Mures, , 540139 Târgu Mures, , Romania;
[email protected] (A.D.M.);
[email protected] (F.T.);
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[email protected] (A.M.) 2 Doctoral School, George Emil Palade University of Medicine, Pharmacy, Science, and Technology of Târgu Mures, , 540139 Târgu Mures, , Romania;
[email protected] 3 Department of Physiopathology, George Emil Palade University of Medicine, Pharmacy, Science, and Technology of Târgu Mures, , 540139 Târgu Mures, , Romania * Correspondence:
[email protected] Received: 7 May 2020; Accepted: 4 June 2020; Published: 6 June 2020 Abstract: One of the most important questions in microbiology nowadays, is how apparently harmless, commensal yeasts like Candida spp. can cause a rising number of infections. The occurrence of the disease requires firstly the attachment to the host cells, followed by the invasion of the tissue. The adaptability translates into a rapid ability to respond to stress factors, to take up nutrients or to multiply under different conditions. By forming complex intracellular networks such as biofilms, Candida spp. become not only more refractive to antifungal therapies but also more prone to cause disease. The inter-microbial interactions can enhance the virulence of a strain. In vivo, the fungal cells face a multitude of challenges and, as a result, they develop complex strategies serving one ultimate goal: survival.