Evolutionary history and spread of the Mycobacterium tuberculosis Latin American and Mediterranean (L4.3/LAM) sublineage, Tunisia - 25/01/23
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Abstract |
Background |
To infer the origin and spread of the Mycobacterium tuberculosis Latin American and Mediterranean (L4.3/LAM) sublineage in a Mediterranean country, Tunisia, where it predominates.
Methods |
We combined Bayesian (STRUCTURE) and maximum likelihood (MIGRAINE) estimation approaches based on a global 24-loci mycobacterial interspersed repetitive units-variable numbers of tandem repeats (MIRU-VNTR24) genotyping dataset consisting of 1573 L4.3/LAM clinical strains from four continents, including 252 isolates originating from Tunisia.
Results |
Phylogenetic analyses coupled with Bayesian estimations suggested that the most predominant L4.3/LAM subpopulation in Tunisia (65.07%), which is dominated by a single clonal complex, TUN4.3_CC1 (94.51%), has evolved from an ancestral pool that is restricted to Europe and Africa, contrasting with the remaining L4.3/LAM subpopulations whose ancestry was traced all over the word. Maximum likelihood analysis revealed that TUN4.3_CC1 has been undergoing a demographic expansion since 131 years ago (CI95%: 90.7–205), thus explaining its preponderance relative to the second most predominant CC, TUN4.3_CC2, whose population was found under contraction.
Conclusions |
The preponderance of L4.3/LAM in Tunisia stems from a 130-year expansion process of a locally evolved clone.
Le texte complet de cet article est disponible en PDF.Highlights |
• | TUN4.3_CC1 is the most prevalent M. tuberculosis L4.3/LAM sublineage clone in Tunisia. |
• | TUN4.3_CC1 has evolved exclusively from a Euro-African pool. |
• | The less prevalent TUN4.3_CC2 is related to the European colonial expansion into Africa. |
• | The population of TUN4.3_CC1 has been expanding for almost 131 years. |
• | Unlike TUN4.3_CC1, the less prevalent TUN4.3_CC2 is undergoing a population contraction. |
Keywords : Mycobacterium tuberculosis, L4.3/LAM sublineage, Clonal complex, High resolution genotyping, Bayesian estimation, Demographic origin, Evolution, Local adaptation
Plan
Vol 138
Article 102297- janvier 2023 Retour au numéroBienvenue sur EM-consulte, la référence des professionnels de santé.
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