TY - JOUR
T1 - Dynamic Subspecies Population Structure of Vibrio cholerae in Dhaka, Bangladesh
AU - Nasreen, Tania
AU - Islam, Mohammad Tarequl
AU - Liang, Kevin Y.H.
AU - Johura, Fatema Tuz
AU - Kirchberger, Paul C.
AU - Hill, Eric
AU - Sultana, Marzia
AU - Case, Rebecca J.
AU - Alam, Munirul
AU - Boucher, Yann F.
N1 - Funding Information:
This work was supported by the Natural Sciences and Engineering Research Council of Canada (NSERC) and the Integrated Microbial Biodiversity program of the Canadian Institute for Advanced Research to YB. We also acknowledge the support of graduate student scholarships from NSERC to TN, and Alberta Innovates Technology-Futures and Faculty of Graduate Studies and Research to TN, MTI, and KYHL.
Publisher Copyright:
© 2021, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.
PY - 2022/10
Y1 - 2022/10
N2 - Cholera has been endemic to the Ganges Delta for centuries. Although the causative agent, Vibrio cholerae, is autochthonous to coastal and brackish water, cholera occurs continually in Dhaka, the inland capital city of Bangladesh which is surrounded by fresh water. Despite the persistence of this problem, little is known about the environmental abundance and distribution of lineages of V. cholerae, the most important being the pandemic generating (PG) lineage consisting mostly of serogroup O1 strains. To understand spatial and temporal dynamics of PG lineage and other lineages belonging to the V. cholerae species in surface water in and around Dhaka City, we used qPCR and high-throughput amplicon sequencing. Seven different freshwater sites across Dhaka were investigated for six consecutive months, and physiochemical parameters were measured in situ. Total abundance of V. cholerae was found to be relatively stable throughout the 6-month sampling period, with 2 × 105 to 4 × 105 genome copies/L at six sites and around 5 × 105 genome copies/L at the site located in the most densely populated part of Dhaka City. PG O1 V. cholerae was present in high abundance during the entire sampling period and composed between 24 and 92% of the total V. cholerae population, only showing occasional but sudden reductions in abundance. In instances where PG O1 lost its dominance, other lineages underwent a rapid expansion while the size of the total V. cholerae population remained almost unchanged. Intraspecies richness of V. cholerae was positively correlated with salinity, conductivity, and total dissolved solids (TDS), while it was negatively correlated with dissolved oxygen (DO) concentration in water. Interestingly, negative correlation was observed specifically between PG O1 and salinity, even though the changes in this variable were minor (0–0.8 ppt). Observations in this study suggest that at the subspecies level, population composition of naturally occurring V. cholerae can be influenced by fluctuations in environmental factors, which can lead to altered competition dynamics among the lineages.
AB - Cholera has been endemic to the Ganges Delta for centuries. Although the causative agent, Vibrio cholerae, is autochthonous to coastal and brackish water, cholera occurs continually in Dhaka, the inland capital city of Bangladesh which is surrounded by fresh water. Despite the persistence of this problem, little is known about the environmental abundance and distribution of lineages of V. cholerae, the most important being the pandemic generating (PG) lineage consisting mostly of serogroup O1 strains. To understand spatial and temporal dynamics of PG lineage and other lineages belonging to the V. cholerae species in surface water in and around Dhaka City, we used qPCR and high-throughput amplicon sequencing. Seven different freshwater sites across Dhaka were investigated for six consecutive months, and physiochemical parameters were measured in situ. Total abundance of V. cholerae was found to be relatively stable throughout the 6-month sampling period, with 2 × 105 to 4 × 105 genome copies/L at six sites and around 5 × 105 genome copies/L at the site located in the most densely populated part of Dhaka City. PG O1 V. cholerae was present in high abundance during the entire sampling period and composed between 24 and 92% of the total V. cholerae population, only showing occasional but sudden reductions in abundance. In instances where PG O1 lost its dominance, other lineages underwent a rapid expansion while the size of the total V. cholerae population remained almost unchanged. Intraspecies richness of V. cholerae was positively correlated with salinity, conductivity, and total dissolved solids (TDS), while it was negatively correlated with dissolved oxygen (DO) concentration in water. Interestingly, negative correlation was observed specifically between PG O1 and salinity, even though the changes in this variable were minor (0–0.8 ppt). Observations in this study suggest that at the subspecies level, population composition of naturally occurring V. cholerae can be influenced by fluctuations in environmental factors, which can lead to altered competition dynamics among the lineages.
KW - Cholera
KW - Endemic
KW - Pandemic
KW - Pandemic generating lineage
KW - Populations
KW - Subspecies
KW - Tania Nasreen and Mohammad Tarequl Islam authors contributed equally
KW - V. cholerae
KW - Vibrio
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UR - http://www.scopus.com/inward/citedby.url?scp=85116903305&partnerID=8YFLogxK
U2 - 10.1007/s00248-021-01838-0
DO - 10.1007/s00248-021-01838-0
M3 - Article
C2 - 34633491
AN - SCOPUS:85116903305
SN - 0095-3628
VL - 84
SP - 730
EP - 745
JO - Microbial Ecology
JF - Microbial Ecology
IS - 3
ER -