Genomic contextualisation of ancient DNA molecular data from an Argentinian fifth pandemic Vibrio cholerae infection

Abstract

Specific lineages of serogroup O1 Vibrio cholerae are notorious for causing cholera pandemics, of which there have been seven since the 1800s. Much is known about the sixth pandemic (1899–1923) and the ongoing seventh pandemic (1961–present), but we know very little about the bacteriology of pandemics 1 to 5. Moreover, although we are learning about the contribution of non-O1 non-pandemic V. cholerae to cholera dynamics during the current pandemic, we know almost nothing about their role in the past. A recent ancient DNA study has presented what may be the first molecular evidence of a V. cholerae infection from the fifth cholera pandemic period (1886–1887 AD) in Argentina. Here, we place the molecular evidence from that study into the genomic context of non-pandemic V. cholerae from Latin America and elsewhere, and show that a gene fragment amplified from ancient DNA is most similar to that of V. cholerae from the Americas, and from Argentina. Our results corroborate and reinforce the findings of the original study, and collectively suggest that even in the 1880s, non-pandemic V. cholerae local to the Americas may have caused sporadic infections in Argentina, just as we know this to have happened during the seventh pandemic in Latin America.

Molecular characterization of Vibrio species isolated from dairy and water samples

“…Contradictory findings were obtained by Ahmed et al 43 , Sarkar et al 44 , Bakhshi et al 51 . Serogroup non O1/O139 have been associated to a large number of cases of diarrhoea in different regions of the world, including Sudan in 1968 44 , 52 , 53 . The lack of the ctx gene in this serogroup of V. cholerae does not preclude the risk posed by its existence 54 , 55 .…”