{"id":677953,"date":"2025-06-30T14:20:26","date_gmt":"2025-06-30T11:20:26","guid":{"rendered":"https:\/\/buradabiliyorum.com\/en\/genetic-bottlenecks-help-explain-which-cholera-strains-become-pandemic-pathogens\/"},"modified":"2025-06-30T14:20:26","modified_gmt":"2025-06-30T11:20:26","slug":"genetic-bottlenecks-help-explain-which-cholera-strains-become-pandemic-pathogens","status":"publish","type":"post","link":"https:\/\/buradabiliyorum.com\/en\/genetic-bottlenecks-help-explain-which-cholera-strains-become-pandemic-pathogens\/","title":{"rendered":"Genetic bottlenecks help explain which cholera strains become pandemic pathogens"},"content":{"rendered":"
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\n \"Researchers
\n The evolutionary history of the pandemic Vibrio cholerae lineage shows that its emergence has not been linear, but shaped by several key genetic bottlenecks that explain its rarity. From a group of bacteria with pre-adaptations for virulence (A), new lineages arise with key gene clusters such as CTX\u03a6 or VPI-1 (B), specific modular arrangements within those clusters (C), and unique allelic variations (D). The right combination of all these elements in this genetic mosaic allows the emergence of pathogenic clones from environmental V. cholerae populations (E). Credit: L\u00f3pez-P\u00e9rez et al. (2025), PNAS<\/i>, 122(22), e2417915122.
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A new study sheds light on one of the great enigmas of microbiology: why only certain strains of common bacteria become pandemic pathogens.<\/p>\n

The work, published<\/a> in Proceedings of the National Academy of Science<\/a>s<\/i>, focuses on Vibrio cholerae, the bacterium that causes cholera. It reveals that its most dangerous form arises from a specific combination of genes and allelic variants that give it an advantage in the human intestine. This research could pave the way for new strategies to predict and prevent future cholera outbreaks.<\/p>\n

The study results from a collaboration between Miguel Hern\u00e1ndez University of Elche (UMH) researcher Mario L\u00f3pez P\u00e9rez and Professor Salvador Almagro-Moreno of the St. Jude Children’s Research Hospital. It also involved UMH Professor Jos\u00e9 M. Haro Moreno and predoctoral researcher Alicia Campos L\u00f3pez, affiliated with the Department of Plant Production and Microbiology.<\/p>\n

Through an extensive analysis of over 1,840 V. cholerae genomes, the researchers identified eleven distinct phylogenetic clusters, with the pandemic group belonging to the largest and located within a lineage shared with environmental strains.<\/p>\n

Their findings suggest that the emergence of pandemic strains, responsible for global cholera outbreaks, is largely dependent on the acquisition of unique modular gene clusters and allelic variations that confer a competitive advantage during intestinal colonization. These act as nonlinear filters that prevent most environmental strains from becoming human pathogens.<\/p>\n

“As a result, only a small group of Vibrio cholerae strains can cause cholera in humans, despite the species’ vast natural diversity,” explains UMH researcher Mario L\u00f3pez, lead author of the study. “We wondered why only this small subset has ever triggered pandemics.”<\/p>\n

The study reveals that the emergence of pandemic V. cholerae clones is constrained by specific genetic bottlenecks. These require: a genetic background pre-adapted for virulence, the acquisition of key gene clusters such as CTX\u03a6 and VPI-1, their organization into specific modular arrangements, and finally, the presence of unique allelic variants.<\/p>\n

“Only when all these elements come together can a strain evolve into a pandemic-capable pathogen,” the researchers explain.<\/p>\n

These features are absent in most environmental V. cholerae strains and app<\/a>ear to grant pandemic clones a key competitive advantage: enhanced ability to colonize the human gut.<\/p>\n

“Interestingly, the genetic traits that enable V. cholerae to infect humans don’t benefit the bacteria in their natural aquatic environment,” L\u00f3pez notes. In the wild, V. cholerae typically lives freely or in association with cyanobacteria colonies, mollusks, or crustaceans.<\/p>\n

Cholera is endemic in parts of the world with poor water, sanitation, and hygiene infrastructure. Outbreaks can also occur after natural disasters that disrupt these systems. The disease is characterized by sudden, severe episodes of watery diarrhea, leading to rapid dehydration and, if untreated, potentially death.<\/p>\n

“Our analytical model could be applied to other environmental bacteria to understand how pathogenic clones emerge from non-pathogenic populations,” L\u00f3pez emphasizes.<\/p>\n

The study also opens the door to more precise surveillance of strains with pandemic potential\u2014an approach that could be highly useful for future public health preparedness.<\/p>\n

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More information:<\/strong>
\n\t\t\t\t\t\t\t\t\t\t\t\tMario L\u00f3pez-P\u00e9rez et al, Allelic variations and gene cluster modularity act as nonlinear bottlenecks for cholera emergence, Proceedings of the National Academy of Sciences<\/i> (2025). DOI: 10.1073\/pnas.2417915122<\/a><\/p>\n<\/p><\/div>\n

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\n\t\t\t\t\t\t\t\t\t\t\t\t\tProvided by
\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\tMiguel Hernandez University of Elche
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\n\t\t\t\t\t\t\t\t\t\t\t\tCitation<\/strong>:
\n\t\t\t\t\t\t\t\t\t\t\t\tGenetic bottlenecks help explain which cholera strains become pandemic pathogens (2025, June 30)
\n\t\t\t\t\t\t\t\t\t\t\t\tretrieved 30 June 2025
\n\t\t\t\t\t\t\t\t\t\t\t\tfrom https:\/\/phys.org\/news<\/a>\/2025-06-genetic-bottlenecks-cholera-strains-pandemic.html\n\t\t\t\t\t\t\t\t\t\t\t <\/p>\n

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