ArticlePLoS neglected tropical diseases2014
Long-term survival and virulence of Mycobacterium leprae in amoebal cysts.
Article in PLoS neglected tropical diseases, 2014. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 48 papers, 1 of them a synthesis that pooled it.
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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
48 citing papers in PubMed, 1 synthesis or guideline pooled it, 102 citations in OpenAlex.
- Reservoirs and transmission routes of leprosy; A systematic review.PLoS neglected tropical diseases · 2020Pooled it
- Associated Factors of Mycobacterium Leprae Infection among People with Leprosy in Kwale County.PLoS neglected tropical diseases · 2025Article
- 4,000-year-old Mycobacterium lepromatosis genomes from Chile reveal long establishment of Hansen's disease in the Americas.Nature ecology & evolution · 2025Article
- Hansen's Disease in Ecuador: Current Status, Knowledge Gaps, and Research Priorities: A Literature Review.Pathogens (Basel, Switzerland) · 2025Review
- Environmental Exposures Relative to Locally Acquired Hansen Disease, United States.Emerging infectious diseases · 2025Article
- Leprosy.Nature reviews. Disease primers · 2024Review
- Potentially Pathogenic Free-Living Amoebae Isolated from Soil Samples from Warsaw Parks and Squares.Pathogens (Basel, Switzerland) · 2024Article
- Human Skin as an Ex Vivo Model for MaintainingTropical medicine and infectious disease · 2024Article
- Article
- CanMicroorganisms · 2023Article
- Ticks are unlikely to play a role in leprosy transmission in the Comoros (East Africa) as they do not harbourFrontiers in medicine · 2023Article
- Pathogenicity and virulence ofVirulence · 2022Review
- The protective role of tissue-resident interleukin 17A-producing gamma delta T cells in MycobacteriumFrontiers in immunology · 2022Article
- Microbial warfare in the wild-the impact of protists on the evolution and virulence of bacterial pathogens.International microbiology : the official journal of the Spanish Society for Microbiology · 2021Review
- Review
- Detection of Mycobacterium leprae DNA in clinical and environmental samples using serological analysis and PCR.Molecular biology reports · 2021Article
- Leprosy in wild chimpanzees.Nature · 2021Article
- Detection of Free-Living Amoebae and Their Intracellular Bacteria in Borehole Water before and after a Ceramic Pot Filter Point-of-Use Intervention in Rural Communities in South Africa.International journal of environmental research and public health · 2021Article
- Article
- One Health Approaches to TraceFrontiers in microbiology · 2021Review
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
10 authors at 3 institutions in 1 country.
Funding
Abstract
Leprosy is a curable neglected disease of humans caused by Mycobacterium leprae that affects the skin and peripheral nerves and manifests clinically in various forms ranging from self-resolving, tuberculoid leprosy to lepromatous leprosy having significant pathology with ensuing disfiguration disability and social stigma. Despite the global success of multi-drug therapy (MDT), incidences of clinical leprosy have been observed in individuals with no apparent exposure to other cases, suggestive of possible non-human sources of the bacteria. In this study we show that common free-living amoebae (FLA) can phagocytose M. leprae, and allow the bacillus to remain viable for up to 8 months within amoebic cysts. Viable bacilli were extracted from separate encysted cocultures comprising three common Acanthamoeba spp.: A. lenticulata, A. castellanii, and A. polyphaga and two strains of Hartmannella vermiformis. Trophozoites of these common FLA take up M. leprae by phagocytosis. M. leprae from infected trophozoites induced to encyst for long-term storage of the bacilli emerged viable by assessment of membrane integrity. The majority (80%) of mice that were injected with bacilli extracted from 35 day cocultures of encysted/excysted A. castellanii and A. polyphaga showed lesion development that was similar to mice challenged with fresh M. leprae from passage mice albeit at a slower initial rate. Mice challenged with coculture-extracted bacilli showed evidence of acid-fast bacteria and positive PCR signal for M. leprae. These data support the conclusion that M. leprae can remain viable long-term in environmentally ubiquitous FLA and retain virulence as assessed in the nu/nu mouse model. Additionally, this work supports the idea that M. leprae might be sustained in the environment between hosts in FLA and such residence in FLA may provide a macrophage-like niche contributing to the higher-than-expected rate of leprosy transmission despite a significant decrease in human reservoirs due to MDT.
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Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.