Phenotypic and Genetic Characterization of Pseudomonas anguilliseptica Strains Isolated from Fish

• Published in: Journal of aquatic animal health 2003-03, Vol.15 (1), p.39-47
• Main Authors: López‐Romalde, Sonia, Magariños, Beatriz, Núñez, Soledad, Toranzo, Alicia E., Romalde, Jesús L.
• Format: Article
• Language: English
• Subjects: Anguilla; Anguilla japonica; Pisces; Pseudomonas anguilliseptica
• ISSN: 0899-7659; 1548-8667
• DOI: 10.1577/1548-8667(2003)015<0039:PAGCOP>2.0.CO;2

The phenotypic and genetic characteristics of a group of European strains of Pseudomonas anguilliseptica isolated from different hosts are described and compared with those of the type strain CECT (Spanish Collection of Type Cultures) 899 originally isolated from Japanese eels Anguilla japonica in Japan. The taxonomic analysis of these isolates revealed high homogeneity of characteristics regardless of the geographic origin and host. Variable results were only obtained for citrate utilization and the hydrolysis of Tween 20 and starch. Based on comparison with conventional tests, consistent results in the miniaturized system API20NE were only achieved for the P. anguilliseptica isolates when bacterial inocula were prepared from blood agar and spectrophotometrically adjusted to an optical density of 1 (at an absorbance of 580 nm). Although P. anguilliseptica is not included in the API database, this miniaturized system can be useful for the identification of this microorganism under the above conditions. Genetic analysis by means of randomly amplified polymorphic DNA demonstrated the existence of variability within P. anguilliseptica. Two major genetic groups were established, which were related to the host origin of the isolates. One group comprised the majority of eel isolates while the other comprised the isolates obtained from other fish species. These results will be important in understanding the epidemiological aspects of P. anguilliseptica.