Role of Polyphosphate Kinase Gene (ppk) for Survival of Vibrio cholerae O1 in Surface Water of Bangladesh

Abstract

Polyphosphate provides a substitute for ATP and energy source when phosphorus is a limiting resource in nature. The present study focuses on the role ofpolyphosphate for the survival of Vibrio cholerae in the aquatic habitats as an autochthonous bacterium. The survival advantages of polyphosphate of V. cholerae O1 having (wild type) and lacking (mutant) polyphosphate kinase (ppk) gene in surface water and with Anabaena variabilis were compared by cultural, Direct Fluorescent Antibody (DFA) and polymerase chain reaction methods in natural water microcosms. The microcosm's water was prepared by filtering and physicochemical parameters were also investigated by standard methods. The results revealed that both fresh and saline water, the wild type strain enhanced survival in cultural conditioned than ppk mutant strain. However, Fluorescent Antibody Direct Viable Counts (FADVC) and Polymerase Chain Reaction (PCR) results noted both strains have the equal survival strategy in viable but nonculturable state (VNC). In conclusion, it could be hypothesized that the polyphosphate inclusion body might keep cultivable and survivable at low phosphate natural environment of the aquatic bacterium.

Growth arrest and a persister state enable resistance to osmotic shock and facilitate dissemination of Vibrio cholerae

“…Human shed V. cholerae experience a dramatic change in osmolarity and nutrient availability when transmitted to fresh water environments, yet its success as a water-born pathogen requires that it survives this stressful transition. Several studies have addressed osmotic challenges to V. cholerae survival, however, most of these have focused on transition to high salinity environments (Chakrabarti et al, 1996;Häse and Mekalanos, 1999;Pflughoeft et al, 2003;Kapfhammer et al, 2005;Nag et al, 2005;Shikuma and Yildiz, 2009;Jahid et al, 2013;Rowe et al, 2013;Shikuma et al, 2013;Möll et al, 2015). Since, during outbreaks and epidemics, V. cholerae is consumed in contaminated drinking water, its ability to withstand low salinity conditions is critical to this mode of transmission.…”