Influence of biological fluids and disinfectants in Candida albicans viability on different hospital surfaces and fomites

• Grant number: 17/22964-2
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: February 01, 2018
• End date: January 31, 2019
• Field of knowledge: Biological Sciences - Microbiology - Biology and Physiology of Microorganisms
• Principal Investigator: Marcus Vinicius Pimenta Rodrigues
• Grantee: Thayná Ruiz Ferreira
• Host Institution: Faculdade de Ciências da Saúde (FCSA). Universidade do Oeste Paulista (UNOESTE). Presidente Prudente , SP, Brazil

Abstract

Candida yeasts can be considered opportunistic pathogens, the main yeast related to Health Care Related Infections (IRAS). The most prevalent species is Candida albicans that presents important virulence factors that allow its survival under adverse conditions, such as biofilm formation and modulation of the pH of the environment. Selective environmental pressure may favor the selection of yeasts capable of remaining viable on abiotic surfaces for long periods, even after disinfection. Considering the relevance of C. albicans in the hospital environment, the present study aims to analyze the viability of this microorganism in different fomites and hospital surfaces, under the influence of biological fluids and disinfectants. The evaluated surfaces will be ceramic floor and egg box mattress, and the fomites will be woven of synthetic fibers and cotton, commonly used in the hospital environment. The standard strain of Candida albicans (CCCD-CC001) will be used as the test microorganism. The yeast will be inoculated as follows: yeast + surface; Yeast + surface + water; Yeast + surface + fluid (urine, blood and saliva) in the proportion 1: 1 and, later, on the surfaces that present greater viability, will be inoculated as follows: yeast + surface + disinfectant (hypochlorite 1% and alcohol 70%); Yeast + surface + water + disinfectant; Yeast + surface + fluid (urine, blood and saliva) + disinfectant, in a ratio of 1: 1: 1. After inoculation, the surfaces will be kept at room temperature for 24 hours, 72 hours and every 7 days for later reading of Colony Forming Units - UFC. For the reading of the UFC the surfaces will be immersed in BHI for 24 hours at 35 ° C. After this period, serial dilution up to 10-9 will be performed from the initial inoculum of 3.0x108 (McFarland 1.0 scale). An aliquot of the highest dilution will be sown on the Sabouraud Dextrose agar by the spread-plate technique, where, after incubation, the colony forming units (CFU / mL) will be counted. The data will be expressed in Base Log 10 and analyzed using non-parametric tests. The Friedman test will be used for dependent variables in pairs of random groups, and the Kruskal-Wallis test will be used for independent variables. The comparison between the studied conditions will be performed using R statistical software (R Foundation for Statistical Computing, Vienna, Austria), being considered as significant the value of p <0.05. It is expected to evaluate the viability of C. albicans in different conditions similar to those of hospital environments. (AU)