title: The occurrence of aerolysin-positive Aeromonas spp. and their cytotoxicity in Norwegian water sources.
abstract: OBJECTIVE
  The aim of the study was to investigate the occurrence of Aeromonas spp. and their aerolysin status in Norwegian natural water sources.
  
  
  RESULTS
  Seventy-one samples from 33 Norwegian water sources were examined for the presence of Aeromonas spp. From most of the sample sites, the strains were isolated on blood-ampicillin-agar and Difco Aeromonas agar simultaneously. The majority of the samples (73/77) contained Aeromonas spp., with an average of 35-100 cfu 100 ml(-1). The highest counts were found in faecally-contaminated water. Using PCR, 445 isolates were screened for the presence of aerolysin, and 79% of them were found to be carriers of the aerolysin gene. A selection of the isolated strains was tested on Vero cell cultures and 83% of them showed cytotoxicity.
  
  
  CONCLUSIONS
  There is widespread occurrence of aerolysin-positive cytotoxic Aeromonas spp. in many different Norwegian natural waters, including drinking water sources.
  
  
  CONCLUSIONS
  The widespread occurrence of potentially-pathogenic Aeromonas spp. in the environment demands that these bacteria should not be ignored in drinking water supplies and in the food industry.
authors.affiliation: The Norwegian School of Veterinary Science, Department of Pharmacology, Microbiology and Food Hygiene, Oslo, Norway. Oyvind.Ormen@veths.no
authors.lastname: Ørmen Ø
authors.lastname: Østensvik Ø
mesh_terms: D000333:Aeromonas / Q000302:isolation & purification* / Q000378:metabolism; D000818:Animals; D001427:Bacterial Toxins / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D001681:Biological Assay; D002522:Chlorocebus aethiops; D005798:Genes, Bacterial; D007473:Ion Channels / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D009664:Norway; D016133:Polymerase Chain Reaction; D052899:Pore Forming Cytotoxic Proteins; D014709:Vero Cells; D014871:Water Microbiology
chemical_list: D001427:Bacterial Toxins; D007473:Ion Channels; D052899:Pore Forming Cytotoxic Proteins; C032676:aerolysin