Isolation of Vermamoeba vermiformis and associated bacteria in hospital water

Microb Pathog. 2015 Mar;80:14-20. doi: 10.1016/j.micpath.2015.02.006. Epub 2015 Feb 16.


To detect new potential pathogens in hospital water, we isolated free-living amoebae in water samples taken from three different hospitals in Marseille (France). The samples were inoculated in media containing saline buffer and various bacteria as nutrient sources. The isolated amoebae were identified by gene sequencing. Among the 105 water samples, taken from 19 sites, we isolated 14 amoebae, of which 9 Vermamoeba vermiformis and 5 Acanthamoeba sp. None of the amoebae showed the presence of obligate bacterial endosymbionts. Because V. vermiformis was most commonly isolated, we used an axenic collection strain to isolate amoeba-resistant bacteria from the same sites. The isolated bacterial species included Stenotrophomonas maltophilia and Legionella sp. Legionella taurinensis was isolated for the first time in association with amoebae. A strict intracellular bacterium was isolated, that may represent a new genus among the Chlamydiales. We propose that it be named "Candidatus Rubidus massiliensis". Our study shows that the isolation and identification of new pathogens associated with amoebae, which were previously performed using Acanthamoeba sp., should instead use V. vermiformis because this organism is more commonly associated with humans and is an essential complement of Acanthamoeba sp. co-culture to study the ecology of hospital water supplies.

Keywords: Amoeba resisting bacteria; Chlamydiales; Vermamoeba vermiformis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amoebozoa / classification
  • Amoebozoa / genetics
  • Amoebozoa / isolation & purification*
  • Amoebozoa / microbiology*
  • Chlamydiales / classification
  • Chlamydiales / genetics
  • Chlamydiales / isolation & purification*
  • Cluster Analysis
  • France
  • Hospitals
  • Legionella / classification
  • Legionella / genetics
  • Legionella / isolation & purification*
  • Microscopy
  • Molecular Sequence Data
  • Phylogeny
  • Polymerase Chain Reaction
  • Sequence Analysis, DNA
  • Sequence Homology
  • Stenotrophomonas maltophilia / classification
  • Stenotrophomonas maltophilia / genetics
  • Stenotrophomonas maltophilia / isolation & purification*
  • Water / parasitology*


  • Water

Associated data

  • GENBANK/HG726047