Atypical flavobacteria recovered from diseased fish in the Western United States

Frontiers in Cellular and Infection Microbiology

Cellular and Infection Microbiology

Brent M. Vuglar¹  Kenneth D. Cain¹  Thomas P. Loch²  Esteban Soto³  Eric K. Pomaranski³  Zeinab Yazdi³  Taylor I. Heckman³  Fernanda de Alexandre Sebastião⁴  Kaveramma Mukkatira⁵ 

[1] Department of Fish and Wildlife Sciences, College of Natural Resources, University of Idaho, Moscow, ID, United States;Department of Fisheries and Wildlife, College of Agriculture and Natural Resources, Department of Pathobiology and Diagnostic Investigation, College of Veterinary Medicine, Michigan State University, East Lansing, MI, United States;Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, Davis, CA, United States;Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, Davis, CA, United States;Fisheries, Embrapa Amazônia Ocidental, Manaus, Amazonas, Brazil;Fish Health Laboratory, California Department of Fish and Wildlife, Rancho Cordova, CA, United States;

关键词: Flavobacteriales;    Flavobacterium;    Chryseobacterium;    16S rRNA;    gyrB;    flavobacteria;   

DOI  :  10.3389/fcimb.2023.1149032

 received in 2023-01-20, accepted in 2023-03-07,  发布年份 2023

来源: Frontiers

【 摘 要 】

Flavobacterial diseases, caused by bacteria in the order Flavobacteriales, are responsible for devastating losses in farmed and wild fish populations worldwide. The genera Flavobacterium (Family Flavobacteriaceae) and Chryseobacterium (Weeksellaceae) encompass the most well-known agents of fish disease in the order, but the full extent of piscine-pathogenic species within these diverse groups is unresolved, and likely underappreciated. To identify emerging agents of flavobacterial disease in US aquaculture, 183 presumptive Flavobacterium and Chryseobacterium isolates were collected from clinically affected fish representing 19 host types, from across six western states. Isolates were characterized by 16S rRNA gene sequencing and phylogenetic analysis using the gyrB gene. Antimicrobial susceptibility profiles were compared between representatives from each major phylogenetic clade. Of the isolates, 52 were identified as Chryseobacterium species and 131 as Flavobacterium. The majority of Chryseobacterium isolates fell into six clades (A-F) consisting of ≥ 5 fish isolates with ≥ 70% bootstrap support, and Flavobacterium into nine (A-I). Phylogenetic clades showed distinct patterns in antimicrobial susceptibility. Two Chryseobacterium clades (F & G), and four Flavobacterium clades (B, G-I) had comparably high minimal inhibitory concentrations (MICs) for 11/18 antimicrobials tested. Multiple clades in both genera exhibited MICs surpassing the established F. psychrophilum breakpoints for oxytetracycline and florfenicol, indicating potential resistance to two of the three antimicrobials approved for use in finfish aquaculture. Further work to investigate the virulence and antigenic diversity of these genetic groups will improve our understanding of flavobacterial disease, with applications for treatment and vaccination strategies.

【 授权许可】

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Copyright © 2023 Heckman, Yazdi, Pomaranski, Sebastião, Mukkatira, Vuglar, Cain, Loch and Soto