The correlation between als3 gene expression and in vivo Candida albicans biofilm formation in mice

Abstract

Objective To study the correlation between expression level of als3 gene and the in vivo biofilm formation of Candida albicans in mice. Methods The real-time polymerase chain reaction (PCR) assay was used to detect als3 gene expressions of the clinical Candida albicans isolates from February 2016 to August 2016 in Tianjing No.1 Central Hospital. According to the expression levels of als3 gene, Candida albicans isolates were divided into high and low-expression groups. Thirty C57 mice were randomly assigned to high-expression group (n=15), low-expression group (n=5) and blank group (n=5). Animal model of Candida albicans biofilm was established based on venous catheter and intraperitoneal injection of Candida albicans. Catheters were removed after two weeks; inverted microscope was used for the observation of Candida albicans biofilm formation and transmission electron microscope was used for the observation of its ultrastructure. After irrigating the catheter, the growth of Candida albicans was observed; real-time PCR was used to detect the expression levels of als3 gene 12, 24, and 48 h after the catheter being removed. In this study, t test was used for measurement data and chi-square test was used for rate comparisons. Results In high-expression group, 11 strains (11/15) formed biofilms. In als3 low-expression group, only one strain (1/10) formed biofilm. The difference between these two group was statistically significant (χ2=9.64, P 0.05). In the als3 high-expression group, the expression of als3 gene declined gradually during the biofilm formation. In the als3 low-expression group, the change of als3 gene expression was not obvious. The expressions of als3 gene over time between two groups were significantly different (t=8.7, 10.3 and 9.2, respectively, all P<0.05). Conclusion The high expression of als3 gene in Candida albicans facilitates the formation of biofilm in vivo. Key words: Candida albicans; Biofilm; Mice model; Gene expression; als3 gene