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In the aquaculture industry, biocides are routinely used to treat parasitosis in fish, and researchers are continually developing sustainable alternatives that can replace these harsh chemicals. In this context, the objective of this study was to evaluate the effectiveness of a new natural compound, BiokosTM, for the treatment against Epistylis sp. in Carassius auratus fish. The infestation was identified by the presence of whitish plaques on the integument of five animals, and the diagnosis was confirmed through skin scrapings. BiokosTM is a lipopeptide derived from the bacteria Pseudomonas that can destroy the functionality of the cell membrane of ciliated protozoa. The action of BiokosTM does not harm animals and the environment because the compound degrades into amino acids and fatty acids within days. A 0.15 m3 (150 L) aquarium was treated with an Ich-AwayTM water conditioner manufactured by the Danish company Sundew ApS, which has BiokosTM as the active ingredient. Six tablets were added to the water daily for two days, and new skin scrapings were performed. The fish were clinically well and no longer possessed lesions or parasites. The results obtained indicate that BiokosTM can be an innovative and more sustainable alternative for controlling epistyliasis in ornamental fish.

The surge in global polymeric waste underscores the imperative for biodegradable materials to substitute traditional polymers. Crucially, advancements are needed for emerging technologies like Materials Extrusion (ME) in additive manufacturing, where current biodegradable materials exhibit limitations. This work was based on the development of a biodegradable composite filament. The inner of the mango seed (kernel) and poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) were used as raw materials. The properties of PHBV and mango by-product mixture were first evaluated by direct-extrusion printing. Then, the feasibility of manufacturing the filaments was studied. Initially, the kernel seed mango was characterized thermally, chemically, and morphologically by DSC, FTIR, and SEM, respectively. It was observed that the addition of mango by-product contributed to the decrease of PHBV crystallinity, resulting in the reduction of printed parts retraction and increases the Tg, as shown by the DMA. The structure of the native starch was preserved due to non-gelatinization, even after processing steps, as indicated by thermal, chemical, and morphological analyses. Finally, PHBV filaments containing mango by-products were fabricated, and prototypes were manufactured by ME to demonstrate the potential for market acceptance and commercialization of the studied filament., Competing Interests: Declaration of competing interest The authors declare no potential conflict of interest., (Copyright © 2024 Elsevier B.V. All rights reserved.)

This study aimed to characterize 300 Aeromonas spp. strains isolated from 123 ornamental fish of 32 different species presenting with septicemia, skin lesions, and/or eye lesions. Within the 300 strains, 53.0% were identified as A. veronii , 41.3% as A. hydrophila , and 5.7% as A. caviae . Among the six virulence genes investigated, the most frequent were act (90.3%) and aer (79.3%). More than 50% of A. hydrophila strains were positive for all the studied genes. A total of 30 virulence profiles were identified, with the five main profiles identified comprising 75% of strains. Only five strains were negative for all genes and were identified as A. caviae and A. veronii . The antimicrobial susceptibility profile was performed for 234 strains, with sulfonamides presenting more than 50% of the resistance rates. Susceptibility was observed mainly for cephalosporins, aminoglycosides, chloramphenicol and piperacillin-tazobactam. Multidrug resistance was detected in 82.5% of the studied strains, including A. caviae with 100% multidrug resistance, and A. hydrophila with 90.9% multidrug resistance. The SE-AFLP analysis resulted in 66 genotypes of A. hydrophila , 118 genotypes of A. veronii , and 14 genotypes of A. caviae , demonstrating the greater heterogeneity of A. veronii and A. caviae . However, no direct correlation was observed between the genotypes and the strains' origins or virulence and resistance profiles.