Vibrio species are common inhabitants of aquatic environments and have been described
in connection with fish and human diseases.
Six Vibrio species were isolated from diseased freshwater and ornamental fish in Poland.
The strains were identified based on morphological and biochemical characteristics and
confirmed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry
(MALDI-TOF-MS) as V. albensis (n=3) from Gymnocephalus cernua, Sander lucioperca,
Paracheirodon innesi, and Xiphophorus hellerii; V. mimicus (n=1) from Xiphophorus maculatus;
and V. vulnificus (n=1) from Nematobrycon palmeri. This is the first time that Vibrio species have
been isolated and described from ornamental fish in Poland. The isolates were resistant to ampicillin (83.3%), gentamicin (16.6%), ciprofloxacin (16.6%), sulfamethoxazole-trimethoprim
(16.6%), and chloramphenicol (16.6%). The multiple antibiotic resistance (MAR) index was
0.00-0.08 for V. albensis, 0.17 for V. mimicus, and 0.33 for V. vulnificus.
Our study confirmed the presence of potentially pathogenic Vibrio species in freshwater
and ornamental fish. Therefore, further monitoring of the presence of Vibrio species, mainly
in ornamental fish, is necessary.