title: Isolation and characterization of potentially human pathogenic, cytotoxin-producing aeromonas strains from retailed seafood in Berlin, Germany.
abstract: The presence of potentially human pathogenic strains of Aeromonas was investigated in 84 samples of seafood which were purchased from retail traders in Berlin, Germany in spring 2000. A total of 134 Aeromonas strains were isolated on selective [GSP agar and Aeromonas (Ryan) agar] and unselective (standard count agar and enterohaemolysin agar) media from 27 (32.1%) of the samples and were classified as Aeromonas hydrophila (67.9%), A. caviae (26.1%) and A. sobria (6.0%) by biotyping. Thirteen (48.1%) of the 27 positive samples contained more than one species of Aeromonas. Production of haemolysins on enterohaemolysin agar was found with 132 (98.5%) of the strains at 28 degrees C and with 130 strains (97.0%) at 37 degrees C growth temperature. Vero cytotoxins were produced by 99 (73.9%) of the strains when grown at 28 degrees C but only by 24 of the strains (17.9%) at 37 degrees C. The latter strains were identified as A. hydrophila (n = 22) and A. sobria (n = 2) which came from 17 (20.2%) samples of raw seafood and from ready-to-eat salted herring 'Matjes' products. Cytotoxin-encoding genes for aerolysin (aer) and haemolysin A (hlyA) were investigated by PCR. Aer and hlyA genes were detected in both, strains which produced toxins only at 28 degrees C and strains which produced toxins at 37 degrees C. Our data indicate that raw seafood and ready-to-eat fish products can harbour potential human pathogenic, cytotoxin producing Aeromonas strains.
authors.affiliation: Technische Fachhochschule Berlin, Fachbereich V, Lebensmitteltechnologie, D-10785 Berlin, Germany.
authors.forename: D
authors.initials: D
authors.lastname: Ullmann
authors.forename: G
authors.initials: G
authors.lastname: Krause
authors.forename: D
authors.initials: D
authors.lastname: Knabner
authors.forename: H
authors.initials: H
authors.lastname: Weber
authors.forename: L
authors.initials: L
authors.lastname: Beutin
mesh_terms: D000333:Aeromonas / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D000818:Animals; D001427:Bacterial Toxins / Q000032:analysis*; D001604:Berlin; D002522:Chlorocebus aethiops; D005506:Food Contamination / Q000032:analysis*; D005516:Food Microbiology; D006801:Humans; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D017747:Seafood / Q000382:microbiology*; D018675:Toxicity Tests; D014709:Vero Cells
chemical_list: D001427:Bacterial Toxins