Psychrobacters and Related Bacteria in Freshwater Fish
Abstract:Three phenotypic identification systems were employed to identify 106 strains of gram-negative, nonmotile, aerobic bacteria obtained during iced storage of wild (Salmo trutta and Esox lucius) and farmed (Oncorhynchus mykiss) freshwater fish. Using diagnostic tables and computer-assisted identification, the isolates were Psychrobacter (64 strains), Acinetobacter (24 strains), Moraxella (6 strains), Chryseobacterium (5 strains), Myroides odoratus (2 strains), Flavobacterium (1 strain), Empedobacter (1 strain), and unidentified (3 strains). Overall similarities of all strains were determined for 108 characters by numerical analysis (simple matching coefficient of similarity [S] and clustering by unweighted pair group average linkage [UPGMA]). At the 77% similarity level, 92 strains formed nine major clusters (3 or more strains) and four small clusters (2 strains). Cluster 1 (25 isolates divided into two main subclusters) could be assigned to Psychrobacter phenylpyruvicus, clusters 2 and 3 (26 isolates) were designated as Psychrobacter immobilis, and clusters 4 (3 isolates) and 7 (4 isolates) were identified as Psychrobacter urativorans and Psychrobacter spp., respectively. Clusters 5 (five isolates), 6 (three isolates), and 9 (five isolates) were labeled as Acinetobacter spp., Acinetobacter johnsonii, and Acinetobacter lwoffii, respectively. Cluster 8 (12 isolates), with a high resemblance to Thornley's phenon 4 (a heterogeneous group of bacteria isolated from poultry and related to Acinetobacter), remained unnamed. The restriction pattern was identical for strains grouped into clusters 2 and 3 (P. immobilis) but was different for the remaining Psychrobacter isolates. A large proportion of isolates belonging to the family Moraxellaceae were closely related. Psychrobacters and A. johnsonii were present in freshly caught fish and river water. In the latter stages of storage, P. phenylpyruvicus and acinetobacters tended to decrease, whereas P. immobilis increased.
Document Type: Research Article
Affiliations: Department of Food Hygiene and Food Technology, Veterinary Faculty, University of León, E-24071-León, Spain
Publication date: March 1, 2000
More about this publication?
- IAFP Members with personal subscriptions to JFP Online: To access full-text JFP or JMFT articles, you must sign-in in the upper-right corner using your Ingenta sign-in details (your IAFP Member Login does not apply to this website). The Journal of Food Protection (JFP) is a refereed monthly publication. Each issue contains scientific research and authoritative review articles reporting on a variety of topics in food science pertaining to food safety and quality. The Journal is internationally recognized as the leading publication in the field of food microbiology with a readership exceeding 11,000 scientists from 70 countries. The Journal of Food Protection is indexed in Index Medicus, Current Contents, BIOSIS, PubMed, Medline, and many others.
Print and online subscriptions are available to IAFP Members and institutional subscribers. IAFP Members with a subscription to JFP Online will have access to all available JFP and JMFT content. Online visitors who are not IAFP Members or journal subscribers will be charged on a pay-per-view basis. Membership and subscription information is available at www.foodprotection.org.
- Information for Authors
- Submit a Paper
- Subscribe to this Title
- Membership Information
- Information for Advertisers
- ingentaconnect is not responsible for the content or availability of external websites