ArticleMicrobial ecology2013
Hartmannella vermiformis inhibition of Legionella pneumophila cultivability.
Article in Microbial ecology, 2013. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 11 papers.
What it found
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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
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Who cites it
11 citing papers in PubMed.
- Viable but non-cultivable state in oral microbiota: a critical review of an underexplored microbial survival strategy.Frontiers in cellular and infection microbiology · 2025Review
- Article
- Strain-Level Characterization ofMicroorganisms · 2022Article
- Viable but nonculturable bacteria and their resuscitation: implications for cultivating uncultured marine microorganisms.Marine life science & technology · 2021Review
- 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
- Review
- Vermamoeba vermiformis: a Free-Living Amoeba of Interest.Microbial ecology · 2018Review
- Determination of viable legionellae in engineered water systems: Do we find what we are looking for?Water research · 2016Review
- Exposure to synthetic gray water inhibits amoeba encystation and alters expression of Legionella pneumophila virulence genes.Applied and environmental microbiology · 2015Article
- The importance of the viable but non-culturable state in human bacterial pathogens.Frontiers in microbiology · 2014Review
- Current Perspectives on Viable but Non-Culturable (VBNC) Pathogenic Bacteria.Frontiers in public health · 2014Review
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
3 authors.
Funding
No grant is acknowledged in the PubMed record.
Abstract
Hartmannella vermiformis and Acanthamoeba polyphaga are frequently isolated from drinking water and permissive to Legionella pneumophila parasitization. In this study, extracellular factor(s) produced by H. vermiformis and A. polyphaga were assessed for their effects on cultivability of L. pneumophila. Page's amoeba saline (PAS) was used as an encystment medium for H. vermiformis and A. polyphaga monolayers, and the culture supernatants (HvS and ApS, respectively) were assessed against L. pneumophila growth. Compared to PAS and ApS, HvS significantly inhibited L. pneumophila strain Philadelphia-1 (Ph-1) cultivability by 3 log(10) colony forming unit (CFU) mL(-1) after 3 days of exposure compared to <0.5 log(10) CFU mL(-1) reduction of strain Lp02 (P < 0.001). Flow cytometric analysis revealed changes in the percentage and cultivability of three bacterial subpopulations: intact/slightly damaged membrane (ISM), undefined membrane status (UD), and mixed type (MT). After 3 days of HvS exposure, the MT subpopulation decreased significantly (31.6 vs 67.2 %, respectively, P < 0.001), while the ISM and UD subpopulations increased (+26.7 and +6.9 %, respectively) with the ISM subpopulation appearing as viable but nonculturable (VBNC) cells. HvS was separated into two fractions based on molecular weight, with more than 99 % of the L. pneumophila inhibition arising from the <5 kDa fraction (P < 0.001). Liquid chromatography indicated the inhibitory molecule(s) are likely polar and elute from a Novapak C18 column between 6 and 15 min. These results demonstrate that H. vermiformis is capable of extracellular modulation of L. pneumophila cultivability and probably promote the VBNC state for this bacterium.
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Registered trials
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