Free-living amoebae and their associated bacteria in Austrian cooling towers

Author(s)
Ute Scheikl, Han-Fei Tsao, Matthias Horn, Alexander Indra, Julia Walochnik
Abstract

Free-living amoebae (FLA) are widely spread in the environment and known to cause rare but often serious infections. Besides this, FLA may serve as vehicles for bacterial pathogens. In particular, Legionella pneumophila is known to replicate within FLA thereby also gaining enhanced infectivity. Cooling towers have been the source of outbreaks of Legionnaires' disease in the past and are thus usually screened for legionellae on a routine basis, not considering, however, FLA and their vehicle function. The aim of this study was to incorporate a screening system for host amoebae into a Legionella routine screening. A new real-time PCR-based screening system for various groups of FLA was established. Three cooling towers were screened every 2 weeks over the period of 1 year for FLA and Legionella spp., by culture and molecular methods in parallel. Altogether, 83.3 % of the cooling tower samples were positive for FLA, Acanthamoeba being the dominating genus. Interestingly, 69.7 % of the cooling tower samples were not suitable for the standard Legionella screening due to their high organic burden. In the remaining samples, positivity for Legionella spp. was 25 % by culture, but overall positivity was 50 % by molecular methods. Several amoebal isolates revealed intracellular bacteria.

Organisation(s)
External organisation(s)
Medizinische Universität Wien, AGES - Österreichische Agentur für Gesundheit und Ernährungssicherheit
Journal
Parasitology Research
Volume
115
Pages
3365-3374
No. of pages
10
ISSN
0932-0113
DOI
https://doi.org/10.1007/s00436-016-5097-z
Publication date
09-2016
Peer reviewed
Yes
Austrian Fields of Science 2012
106022 Microbiology
Keywords
ASJC Scopus subject areas
Veterinary Medicine(all), Insect Science, Infectious Diseases, Parasitology
Portal url
https://ucrisportal.univie.ac.at/en/publications/freeliving-amoebae-and-their-associated-bacteria-in-austrian-cooling-towers(804f6f0c-6f70-4b5f-85f8-6b3720ae4bbb).html