Copyright ©The Author(s) 2016. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Sep 7, 2016; 22(33): 7402-7414
Published online Sep 7, 2016. doi: 10.3748/wjg.v22.i33.7402
Polyphosphate and associated enzymes as global regulators of stress response and virulence in Campylobacter jejuni
Anand Kumar, Dharanesh Gangaiah, Jordi B Torrelles, Gireesh Rajashekara
Anand Kumar, Gireesh Rajashekara, 170 Food Animal Health Research Program and Department of Veterinary Preventive Medicine, College of Veterinary Medicine, The Ohio State University, Wooster, OH 44691, United States
Anand Kumar, Biosecurity and Public Health, Bioscience Division, Los Alamos National Laboratory, Los Alamos, NM 87545, United States
Dharanesh Gangaiah, Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, IN 46202, United States
Jordi B Torrelles, Department of Microbial Infection and Immunity, Center for Microbial Interface Biology, the Ohio State University, Columbus, OH 43210, United States
Author contributions: All authors contributed equally to this paper with conception and design of the study, literature review and analysis, drafting and critical revision and editing, and approval of the final version.
Supported by Ohio Agricultural Research and Development Center, the Ohio State University, and the Agriculture and Food Research Initiative, No. 2012-68003-19679.
Conflict-of-interest statement: No potential conflicts of interest.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:
Correspondence to: Gireesh Rajashekara, DVM, PhD, 170 Food Animal Health Research Program and Department of Veterinary Preventive Medicine, College of Veterinary Medicine, The Ohio State University, 1680 Madison Avenue, Wooster, OH 44691, United States.
Telephone: +1-330-2633745 Fax: +1-330-2633677
Received: March 26, 2016
Peer-review started: March 27, 2016
First decision: May 27, 2016
Revised: June 3, 2016
Accepted: July 20, 2016
Article in press: July 20, 2016
Published online: September 7, 2016

Campylobacter jejuni (C. jejuni), a Gram-negative microaerophilic bacterium, is a predominant cause of bacterial foodborne gastroenteritis in humans worldwide. Despite its importance as a major foodborne pathogen, our understanding of the molecular mechanisms underlying C. jejuni stress survival and pathogenesis is limited. Inorganic polyphosphate (poly P) has been shown to play significant roles in bacterial resistance to stress and virulence in many pathogenic bacteria. C. jejuni contains the complete repertoire of enzymes required for poly P metabolism. Recent work in our laboratory and others have demonstrated that poly P controls a plethora of C. jejuni properties that impact its ability to survive in the environment as well as to colonize/infect mammalian hosts. This review article summarizes the current literature on the role of poly P in C. jejuni stress survival and virulence and discusses on how poly P-related enzymes can be exploited for therapeutic/prevention purposes. Additionally, the review article identifies potential areas for future investigation that would enhance our understanding of the role of poly P in C. jejuni and other bacteria, which ultimately would facilitate design of effective therapeutic/preventive strategies to reduce not only the burden of C. jejuni-caused foodborne infections but also of other bacterial infections in humans.

Keywords: Campylobacter jejuni, Stress tolerance, Inorganic polyphosphate, Virulence, Colonization/infection

Core tip: Recent studies show that inorganic polyphosphate (poly P) plays several important roles in the biology of Campylobacter jejuni (C. jejuni), a major cause of bacterial foodborne gastroenteritis in humans. This review summarizes the latest findings on the role of poly P in C. jejuni stress survival and virulence, provides directions for future investigation, and discusses the potential of polyphosphate kinase enzymes as drug/vaccine targets to control C. jejuni infections in humans.