title: Seasonal dynamics of Vibrio cholerae and its phages in riverine ecosystem of Gangetic West Bengal: cholera paradigm.
abstract: The Gangetic delta is a century-old cholera endemic belt where the role of riverine-estuarine ecosystem in cholera transmission has never been elucidated. Seasonality, distribution, and abundance of environmental Vibrio cholerae O1/O139 and vibriophage in Hooghly riverine-estuarine environment and their correlation with cholera incidence pattern in West Bengal, India, have been analyzed for the first time across summer, monsoon, and winter months. A total of 146 water samples collected from two sites of the Hooghly River (Howrah and Diamond Harbour) were analyzed physicochemically along with cultivable Vibrio count (CVC), V. cholerae O1/O139, and vibriophages. V. cholerae O1 was detected in 56 (38.3%) samples, while 66 (45.2%) were positive for V. cholerae O1 phages. Flood tide, water temperature (31 ± 1.6 °C), and turbidity (≥250 nephelometric turbidity unit (NTU)) significantly stimulated V. cholerae and vibriophage abundance in riverine ecosystem. Solitary existence of V. cholerae O1 and phages (p < 0.0001) in aquatic environment divulges the dominance of either of the entity (V. cholerae O1 or V. cholerae O1 Φ) on the other. Significant association (p < 0.05) between Kolkata cholera cases and V. cholerae O1 in aquatic environment implies the role of riverine-estuarine ecosystem in cholera transmission. A "biomonitoring tool" of physicochemical stimulants, tidal, and climatic variants has been proposed collating V. cholerae and phage dynamics that can forewarn any impending cholera outbreak.
authors.affiliation: Division of Microbiology, National Institute of Cholera and Enteric Diseases, Indian Council of Medical Research, P-33, CIT Road, Scheme-XM, Beliaghata, Kolkata, 700 010, India.
authors.forename: Subham
authors.initials: S
authors.lastname: Mookerjee
authors.forename: Abhishek
authors.initials: A
authors.lastname: Jaiswal
authors.forename: Prasenjit
authors.initials: P
authors.lastname: Batabyal
authors.forename: Marc H
authors.initials: MH
authors.lastname: Einsporn
authors.forename: Ruben J
authors.initials: RJ
authors.lastname: Lara
authors.forename: Banwarilal
authors.initials: B
authors.lastname: Sarkar
authors.forename: Sucharit Basu
authors.initials: SB
authors.lastname: Neogi
authors.forename: Anup
authors.initials: A
authors.lastname: Palit
mesh_terms: D001435:Bacteriophages / Q000254:growth & development; D002771:Cholera / Q000453:epidemiology; D004196:Disease Outbreaks; D017753:Ecosystem; D004777:Environment; D004784:Environmental Monitoring; D006801:Humans; D007194:India / Q000453:epidemiology; D045483:Rivers / Q000382:microbiology*; D012621:Seasons; D014734:Vibrio cholerae / Q000254:growth & development*; D014871:Water Microbiology