(Press-News.org)
A new study by the Genomics and Microbial Evolution Group at the Miguel Hernández University of Elche (UMH) together with the Department of Host-Microbe Interactions at St. Jude Children’s Research Hospital in Memphis, USA, sheds light on one of the great enigmas of microbiology: why only certain strains of common bacteria become pandemic pathogens. The work, published in the prestigious journal Proceedings of the National Academy of Sciences (PNAS), 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.
The study results from a collaboration between UMH researcher Mario López Pérez and Professor Salvador Almagro-Moreno of the St. Jude Children’s Research Hospital. It also involved UMH Professor José M. Haro Moreno and predoctoral researcher Alicia Campos López, affiliated with the Department of Plant Production and Microbiology.
Through an extensive analysis of over 1,840 Vibrio 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. 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.
“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 López, lead author of the study. “We wondered why only this small subset has ever triggered pandemics.”
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 CTXΦ and VPI-1, their organization into specific modular arrangements, and finally, the presence of unique allelic variants. “Only when all these elements come together can a strain evolve into a pandemic-capable pathogen,” the researchers explain.
These features are absent in most environmental V. cholerae strains and appear to grant pandemic clones a key competitive advantage: enhanced ability to colonize the human gut.
“Interestingly, the genetic traits that enable V. cholerae to infect humans don’t benefit the bacteria in their natural aquatic environment,” López notes. In the wild, V. cholerae typically lives freely or in association with cyanobacteria colonies, mollusks, or crustaceans.
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.
“Our analytical model could be applied to other environmental bacteria to understand how pathogenic clones emerge from non-pathogenic populations,” López emphasizes. The study also opens the door to more precise surveillance of strains with pandemic potential—an approach that could be highly useful for future public health preparedness.
The research was supported by the U.S. National Science Foundation (NSF) through the CAREER program (#2045671) and by the Burroughs Wellcome Fund’s Investigator in the Pathogenesis of Infectious Disease program (#1021977). It also received funding from the Spanish “MICRO3GEN” project (PID2023-150293NB-I00), co-financed by the European Regional Development Fund (FEDER) and managed by the Spanish Ministry of Economy, Industry, and Competitiveness.
END
PISCATAWAY, NJ – For years now, U.S. police departments have employed officers who are trained to be experts in detecting “drugged driving.” The problem is, however, that the methods those officers use are not based on science, according to a new editorial in the Journal of Studies on Alcohol and Drugs.
With marijuana now legal in many U.S. states, the need for reliable tests for marijuana impairment is more pressing than ever. Police can evaluate alcohol-intoxicated drivers by using an objective measure of breath ...
Anaerobic bacteria – masters of survival without oxygen
Anaerobic bacteria were among the first life forms on earth and existed at a time when there was no oxygen in the atmosphere. While many organisms depend on an oxygen-rich environment to survive, anaerobes thrive in places where others cannot – in completely oxygen-free habitats such as the human gut or the ocean floor. The enzymes of these bacteria are even sensitive to oxygen. Their remarkable adaptability is increasingly attracting the attention of researchers.
Anaerobic bacteria often produce unusual substances. This makes ...
COLUMBUS, Ohio – Studies show that the average attention span is now only eight seconds. That’s about as much time as it takes to read a few sentences before being distracted.
A new national survey of 1,000 American adults commissioned by The Ohio State University Wexner Medical Center and College of Medicine finds that stress and anxiety contribute most to a short attention span (43%), followed by lack of sleep (39%) and digital devices (35%).
Other contributing factors include boredom or lack of interest (31%); multitasking (23%); lack of physical activity (21%); poor diet/hydration (20%) and medical conditions such as ADHD ...
In documenting and recording society’s collective data on an unprecedented scale, artificial intelligence is becoming humanity’s historian – changing the way we record information for posterity.
But AI’s inadvertent role as memory-keeper raises profound concerns for today’s historians. Unlike human historians who explicitly document their methodologies, AI systems are creating the historical archives of the future without crucial transparency around how sources are selected, weighted, and interpreted.
This undermines a fundamental principle of historical scholarship, that methodologies should be visible and contestable. In the new book ...
(Paris, France, Monday, 30 June 2025) A new international study presented today at the 41st Annual Meeting of the European Society of Human Reproduction and Embryology (ESHRE) reveals that IVF cycles involving male partners over the age of 45 carry significantly increased miscarriage risks and lower live birth rates – even when young donor eggs are used.[1]
By isolating paternal age from female reproductive factors through the exclusive use of donor eggs from young women, the study provides robust evidence that male age plays a critical role in reproductive success, challenging the common assumption ...
(Monday 30 June 2025, London, United Kingdom) A pioneering study has provided unprecedented insights into the immune response following pig-to-human kidney xenotransplantation.1
The findings, presented today at the ESOT Congress 2025, mark a significant step forward in overcoming the biggest challenge in xenotransplantation: rejection by the human immune system.
Using cutting-edge spatial molecular imaging, researchers mapped how human immune cells interact with pig kidney tissue in transplanted organs, revealing critical ...
(Paris, France, Monday, 30 June 2025) A new study presented today at the 41st Annual Meeting of the European Society of Human Reproduction and Embryology (ESHRE) reveals that women with polycystic ovary syndrome (PCOS) have distinct gut microbiota and metabolic signatures linked to premature endometrial ageing and a higher risk of adverse pregnancy outcomes.[1]
The research highlights a sharp reduction in the beneficial gut bacterium Parabacteroides merdae (P. merdae), alongside elevated levels of branched-chain amino ...
(Paris, France, Monday, 30 June 2025) A simple blood test taken in the first trimester of pregnancy could accurately identify women at risk of developing preeclampsia five months before clinical diagnosis, according to new research presented today at the 41st Annual Meeting of the European Society of Human Reproduction and Embryology (ESHRE).[1]
Using a cell-free RNA (cfRNA) “liquid biopsy” of maternal plasma, researchers at the Carlos Simon Foundation and iPremom enrolled 9,586 pregnant women from 14 hospitals across Spain between September 2021 and June 2024. In a nested case-control analysis of 216 participants, they successfully predicted both early-onset and late-onset ...
(Monday, 30 June 2025, London, United Kingdom) A team of international scientists has made a major leap forward in diabetes research by successfully 3D printing functional human islets using a novel bioink. Presented today at the ESOT Congress 2025, the new technology could pave the way for more effective and less invasive treatment options for people living with type 1 diabetes (T1D).1
The breakthrough involved printing human islets – the insulin-producing clusters of cells in the pancreas – using a customised bioink made from alginate and decellularised human pancreatic tissue. This approach produced durable, high-density islet structures that remained alive and functional ...
Even small drops in national income can significantly increase the risk of various forms of childhood malnutrition- not only undernutrition but also overweight and obesity, shows a study led by the Barcelona Institute for Global Health (ISGlobal), an institution supported by “la Caixa” Foundation. The study, published in Lancet Global Health, identifies pregnancy and the first 1,000 days of life as especially vulnerable periods where targeted interventions can make a big difference.
One in four children worldwide lives in severe food poverty. And many low- and middle-income countries ...
