Downloaded from www.microbiologyresearch.org by IP: 54.70.40.11 On: Wed, 07 Nov 2018 17:34:53 Adhesion and biofilm formation in artificial saliva and susceptibility of yeasts isolated from chronic kidney patients undergoing haemodialysis Paula Assis Queiroz, Janine Silva Ribeiro Godoy, Patrı ´cia de Souza Bonfim Mendonc ¸a, Raı ´ssa Bocchi Pedroso, Terezinha Inez Estivalet Svidzinski and Melyssa Negri Correspondence Melyssa Negri melyssanegri@gmail.com Department of Clinical Analysis and Biomedicine, Universidade Estadual de Maringa ´ (UEM), Maringa ´ , Parana ´ , Brazil Yeasts of the genera Candida and Saccharomyces are opportunist pathogens and cause oral lesions, especially in immunocompromised patients. This study assessed yeasts isolated from chronic kidney patients undergoing haemodialysis for their adhesion capacity, biofilm formation and susceptibility to antifungal agents. Ten isolates of Candida spp. and one isolate of Saccharomyces cerevisiae were tested for adhesion to buccal epithelial cells (BECs), adhesion and formation of biofilm in artificial saliva and their susceptibility profile to antifungal agents. Adhesion and biofilm formation were undertaken in polystyrene plates with artificial saliva, whilst susceptibility to antifungal agents was evaluated by broth microdilution. Candida parapsilosis had the highest adhesion index in BECs (154.55¡22.13) and Candida rugosa was the species with the highest adhesion capacity (18 398 Abs cm 22 ) in abiotic surface with artificial saliva. Candida albicans provided the greatest biofilm formation (2035 Abs cm 22 ¡0.09) but was revealed to be susceptible to the five antifungal agents under analysis. However, some non-albicans Candida isolates showed a lower susceptibility for the antifungal agents itraconazole, fluconazole and voriconazole. All of the species were sensitive to amphotericin B and nystatin. The current analysis showed that yeasts isolated from the mouth of chronic kidney patients undergoing haemodialysis varied significantly with regard to their capacity for adherence, biofilm formation and susceptibility to antifungal agents, underscoring the high virulence of non-albicans Candida species. Received 21 January 2015 Accepted 29 June 2015 INTRODUCTION Yeasts of the genera Candida and Saccharomyces are opportunist yeasts and belong to the human microbiota, causing lesions in the mouth, especially under immuno- compromising conditions. The genus Candida comprises an extremely heterogeneous group of fungal organisms with more than 17 different species implicated in human candidosis. However, over 90% of invasive infections are caused by Candida albicans, followed by non-albicans Candida (NAC) species, such as Candida glabrata, Candida parapsilosis, Candida tropicalis and Candida krusei; the number of infections due to NAC species has increased significantly in recent years (Guinea, 2014; Ortega et al., 2011; Tamura et al., 2007). Saccharomyces cerevisiae is also known to be an emergent micro-organism in immunocompromised patients, which may be associated with the use of probiotics. It is generally associated with yeasts of the genus Candida, with high mortality rates (Enache-Angoulvant & Hennequin, 2005; Eren et al., 2014; Silva et al., 2011a). Patients with chronic kidney insufficiency and kidney transplant patients are the populations with the highest risk of oral lesions and evolution to fungaemia (Serefhanoglu et al., 2012). Owing to their exposure to various procedures and to constant changes in their meta- bolic conditions, chronic kidney insufficiency patients are susceptible to opportunist infections. Haemodialysis is indicated as one of the main risk factors for fungaemia in these patients (Conde-Rosa et al., 2010). Fungal proliferation and the development of infections are also potentiated by other factors: host factors (use of medicines, diabetes mellitus), local factors (dental prosthesis, saliva components) and yeast intrinsic factors Abbreviations: AI, adherence index; BEC, buccal epithelial cell; NAC, non-albicans Candida Journal of Medical Microbiology (2015), 64, 960–966 DOI 10.1099/jmm.0.000122 000122 G 2015 The Authors Printed in Great Britain 960