AUTHOR=Bhattaram Varunkumar , Upadhyay Abhinav , Yin Hsin-Bai , Mooyottu Shankumar , Venkitanarayanan Kumar 

TITLE=Effect of Dietary Minerals on Virulence Attributes of Vibrio cholerae

JOURNAL=Frontiers in Microbiology

VOLUME=8

YEAR=2017

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2017.00911

DOI=10.3389/fmicb.2017.00911

ISSN=1664-302X

ABSTRACT=<p><italic>Vibrio cholerae</italic> is a water-borne pathogen responsible for causing a toxin-mediated profuse diarrhea in humans, leading to severe dehydration and death in unattended patients. With increasing reports of antibiotic resistance in <italic>V. cholerae</italic>, there is a need for alternate interventional strategies for controlling cholera. A potential new strategy for treating infectious diseases involves targeting bacterial virulence rather than growth, where a pathogen’s specific mechanisms critical for causing infection in hosts are inhibited. Since bacterial motility, intestinal colonization and cholera toxin are critical components in <italic>V. cholerae</italic> pathogenesis, attenuating these virulence factors could potentially control cholera in humans. In this study, the efficacy of sub-inhibitory concentration (SIC, highest concentration not inhibiting bacterial growth) of essential minerals, zinc (Zn), selenium (Se), and manganese (Mn) in reducing <italic>V. cholerae</italic> motility and adhesion to intestinal epithelial cells (Caco-2), cholera toxin production, and toxin binding to the ganglioside receptor (GM1) was investigated. Additionally, <italic>V. cholerae</italic> attachment and toxin production in an <italic>ex vivo</italic> mouse intestine model was determined. Further, the effect of Zn, Se and Mn on <italic>V. cholerae</italic> virulence genes, <italic>ctxAB</italic> (toxin production), <italic>fliA</italic> (motility), <italic>tcpA</italic> (intestinal colonization), and <italic>toxR</italic> (master regulon) was determined using real-time quantitative PCR. All three minerals significantly reduced <italic>V. cholerae</italic> motility, adhesion to Caco-2 cells, and cholera toxin production <italic>in vitro</italic>, and decreased adhesion and toxin production in mouse intestine <italic>ex vivo</italic> (<italic>P</italic> &lt; 0.05). In addition, Zn, Se, and Mn down-regulated the transcription of virulence genes, <italic>ctxAB, fliA</italic>, and <italic>toxR.</italic> Results suggest that Zn, Se, and Mn could be potentially used to reduce <italic>V. cholerae</italic> virulence. However, <italic>in vivo</italic> studies in an animal model are necessary to validate these results.</p>