Shyan Mascarenhas , Harold P. Hodgins , Andrew C. Doxey
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引用次数: 0
Abstract
Background
Ancient DNA collected from archaeological specimens not only provides a window into ancient human genetic diversity but also contains a rich mixture of associated microbial DNA including potential pathogens. In recent work, we identified C. tetani and tetanus neurotoxin (TeNT) genes in ancient DNA datasets collected from human archaeological specimens. However, the reasons underlying the occurrence of these toxin genes and the extent to which other toxin genes are present in ancient DNA is unclear.
Methods
Here, we performed a large-scale analysis of 6435 ancient DNA (aDNA) sequencing datasets including human and non-human sources, searching for 49 clostridial neurotoxin types and subtypes, and 3 additional unrelated toxins.
Results
Our search identified a total of 105 ancient DNA datasets (1.6 %) containing significant matches to one or more neurotoxin genes. Consistent with our earlier work, TeNT genes were most common, found in 50 ancient DNA datasets. In addition, we identified sequences encoding diverse botulinum neurotoxins including BoNT/C (40 samples), BoNT/D (6 samples), BoNT/B (4 samples), BoNT/E (1 sample), and the Enterococcus-associated BoNT/En (10 samples). TeNT genes were detected in a broad range of ancient samples including human and animal (horse, wild bear, chimpanzee, gorilla, dog) remains, whereas the largest diversity of toxins was detected in aDNA from Egyptian mummies. Phylogenetic and sequence analysis of the identified matches revealed close identity to modern forms of these toxins. Damage analysis revealed several toxin genes with hallmarks of ancient DNA associated damage, indicative of an ancient origin.
Conclusions
Our work reveals that clostridial neurotoxin genes occur frequently in aDNA samples, including human and animal-associated toxin variants. We conclude that the frequent association of these genes with aDNA likely reflects a strong ecological association of pathogenic clostridia with decaying human and animal remains and possible post-mortem colonization of these samples.
期刊介绍:
Toxicon has an open access mirror Toxicon: X, sharing the same aims and scope, editorial team, submission system and rigorous peer review. An introductory offer Toxicon: X - full waiver of the Open Access fee.
Toxicon''s "aims and scope" are to publish:
-articles containing the results of original research on problems related to toxins derived from animals, plants and microorganisms
-papers on novel findings related to the chemical, pharmacological, toxicological, and immunological properties of natural toxins
-molecular biological studies of toxins and other genes from poisonous and venomous organisms that advance understanding of the role or function of toxins
-clinical observations on poisoning and envenoming where a new therapeutic principle has been proposed or a decidedly superior clinical result has been obtained.
-material on the use of toxins as tools in studying biological processes and material on subjects related to venom and antivenom problems.
-articles on the translational application of toxins, for example as drugs and insecticides
-epidemiological studies on envenoming or poisoning, so long as they highlight a previously unrecognised medical problem or provide insight into the prevention or medical treatment of envenoming or poisoning. Retrospective surveys of hospital records, especially those lacking species identification, will not be considered for publication. Properly designed prospective community-based surveys are strongly encouraged.
-articles describing well-known activities of venoms, such as antibacterial, anticancer, and analgesic activities of arachnid venoms, without any attempt to define the mechanism of action or purify the active component, will not be considered for publication in Toxicon.
-review articles on problems related to toxinology.
To encourage the exchange of ideas, sections of the journal may be devoted to Short Communications, Letters to the Editor and activities of the affiliated societies.