Vibrio infection in freshwater fish in Poland.

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.

Combined antimicrobial action of streptomycin and terpenes against atypical mycobacteria isolated from fish.

The aim of this study was to investigate the antimycobacterial activity of 39 free terpenes and their activity in combination with streptomycin. Antimicrobial activity was first evaluated by screening 39 free terpenes at concentrations from 1.56 to 400 µg/mL. None of these exhibited positive effects against any of the nontuberculous mycobacteria (NTM) strains tested. However, six of the 39 terpenes (isoeugenol, nerol, (+)-α-terpineol, (1R)-(-)-myrtenol, (+)-terpinen-4-ol, and eugenol) were shown to enhance the activity of streptomycin against the NTM strains isolated from diseased ornamental fish.

Evaluation of the anti-mycobacterial activity and composition of Carlina acaulis L. root extracts.

Nontuberculous mycobacteria (NTM) have recently emerged as important bacterial pathogens of animals and humans. Of particular concern is the high level of antimicrobial resistance displayed by these organisms, which complicates treatment and potential successful outcomes. Here, we evaluated the potential of Carlina acaulis L. as a source of novel anti-mycobacterial agents. Our goal was to measure the activity of aqueous, ethanol, and chloroform C. acaulis root extracts against 99 NTM strains. GC-MS spectroscopy analyses were performed to deliver qualitative and quantitative data on the composition of C. acaulis extract. In our study, we have shown for the first time the activity of C. acaulis extracts against NTM. The highest activity was exhibited by the chloroform extract, which inhibited the growth of more than 90% of the strains at the dose of 100 µg/mL (MIC90 = 100 µg/mL). The results of the GC-MS analysis of the C. acaulis chloroform extract contributed to the identification of 37 compounds, with carlina oxide as the most representative compound (69.52%) followed by 3,4-dihydro-2H-phenanthren- -1-one (6.54%) and stigmast-5-en-3-ol (4.14%). Our results indicate that C. acaulis chloroform and ethanol extracts have potential for treatment of NTM infections and that this plant contains anti-mycobacterial compounds.

Effect of alkaloid berberine on the susceptibility of nontuberculous mycobacteria to antibiotics.

Nontuberculous mycobacteria (NTM) have recently emerged as important bacterial pathogens of both animals and humans. In this study, we aimed to evaluate the effect of a combination of ten antibiotics with an inhibitor of efflux pumps (EPI), i.e. berberine (BER), against 6 strains of NTM. Our results showed that the BER potentiated the anti-mycobacterial activities of the antibiotics. Overall, our findings show the importance of BER in increasing the efficacy of antibiotics in NTM.

Parasiticidal effects of Tanacetum vulgare extract against Ichthyophthirius multifiliis.

Ichthyophthiriasis, which is caused by Ichthyophthirius multifiliis (Ich) infections, has a severe impact on productivity in freshwater aquaculture. These infections were previously treated effectively with malachite green, a compound that is now banned on fish farms due to its carcinogenicity. To find efficacious drugs to control Ich, flowers of tansy Tanacetum vulgare were evaluated for their antiprotozoal activity. Tanacetum vulgare extract significantly reduced the survival of Ich trophonts and theronts. In vitro, the extract killed all trophonts at 3200 mg l-1, terminated tomont reproduction at 50 mg l-1, and caused mortality of all theronts at 100 mg l-1. T. vulgare extract may be a new and efficacious drug for the control of Ich.

Parasiticidal effects of Eclipta alba and Arctium lappa extracts against Ichthyophthirius multifiliis.

Ichthyophthiriasis, commonly known as white spot disease, occurs in both wild and cultured fish and is responsible for heavy economic losses to the aquaculture industry. In past decade, several chemical therapeutants were used to treat ichthyophthiriasis, but the effective drugs, such as malachite green, have been banned for use in food fish due to its genotoxic and carcinogenic properties. To find efficacious drugs to control Ichthyophthirius multifiliis (Ich), whole Eclipta alba plants and dried root of Arctium lappa were evaluated for their antiprotozoal activity. E. alba and A. lappa extracts significantly reduced the survival of Ich trophonts and theronts. In vitro, the E. alba and A. lappa methanol extracts killed all trophonts at 3200 mg l-1. All trophonts were killed after exposure to E. alba aqueous extract at 3200 mg l-1. The methanol extracts of E. alba and A. lappa killed 100% of I. multifiliis theronts at 400 mg l-1 and 800 mg l-1, respectively. The aqueous extract of E. alba and A. lappa killed 100% of I. mulitifiliis theronts at 1600 mg l-1 and 3200 mg l-1, respectively. E. alba and A. lappa extracts may be new and efficacious drugs for the control of ichthyophthiriasis.

Inhibitory activities of essential oils against Babesia canis.

The in vitro anti-Babesia canis activities of nine essential oils were investigated. Among the tested essential oils Achillea millefolium, Eugenia caryophyllus and Citrus grandis were the most active (IC50 values of 51.0, 60.3 and 61.3 µg/mL, respectively). The oils from Abies sibirica, Rosmarinus officinalis, Eucalyptus globulus, Cinnamonum zeylanicum, Mentha piperita and Pinus sylvestris were less active (IC50 values of 134.3, 237.3, 239.3, 367.9, 837.5 and 907.3 µg/mL, respectively). The results support the concept that some essential oil constituents may be useful in the clinical management of babesiosis.

Effect of dietary supplementation with Echinacea purpurea on vaccine efficacy against infection with Flavobacterium columnare in zebrafish (Danio rerio).

The effect of dietary Echinacea purpurea (EP) on the response of zebrafish (Danio rerio) to a Flavobacterium columnare vaccine was investigated. Two hundred D. rerio with an average weight of 290 ± 40 g were selected and fed different levels of E. purpurea (5 g kg(-1) diet--group 1, 10 g kg(-1) diet--group 2, 20 g kg(-1) diet--group 3, 30 g kg(-1) diet--group 4, and 0 g kg(-1) diet--group 5). Experimental feeding was begun 3 weeks prior to bath immunization and continued until the end of the experiment. Twenty-eight days after immunization the fish were challenged by bath immersion with F. columnare at a concentration of 1 x 10(6) CFU/ml. The relative percent survival of the experimental groups (1, 2, 3, 4 and 5) was 5.0, 6.0, 30.0, 36.0 and 5.0, respectively. In conclusion, diet supplementation with E. purpurea may effectively enhance the response of zebrafish to a F. columnare vaccine.