Biofilm formation of Francisella noatunensis subsp. orientalis.
Francisella noatunensis subsp. orientalis (Fno) is an emergent fish pathogen in both marine and fresh water environments. The bacterium is suspected to persist in the environment even without the presence of a suitable fish host. In the present study, the influence of different abiotic factors such as salinity and temperature were used to study the biofilm formation of different isolates of Fno including intracellular growth loci C (iglC) and pathogenicity determinant protein A (pdpA) knockout strains. Finally, we compared the susceptibility of planktonic and biofilm to three disinfectants used in the aquaculture and ornamental fish industry, namely Virkon(®), bleach and hydrogen peroxide. The data indicates that Fno is capable of producing biofilms within 24 h where both salinity as well as temperature plays a role in the growth and biofilm formation of Fno. Mutations in the iglC or pdpA, both known virulence factors, do not appear to affect the capacity of Fno to produce biofilms, and the minimum inhibitory concentration, and minimum biocidal concentration for the three disinfectants were lower than the minimum biofilm eradication concentration values. This information needs to be taken into account if trying to eradicate the pathogen from aquaculture facilities or aquariums.
Department of Medicine and Epidemiology, University of California-Davis, School of Veterinary Medicine, Davis, CA 95616, USA; Department of Biomedical Sciences, Ross University School of Veterinary Medicine, P.O. Box 334, Basseterre, St. Kitts, West Indies. Electronic address: sotomartinez@ucdavis.edu.
Esteban
E
Soto
Department of Biomedical Sciences, Ross University School of Veterinary Medicine, P.O. Box 334, Basseterre, St. Kitts, West Indies.
Iona
I
Halliday-Simmonds
Department of Biomedical Sciences, Ross University School of Veterinary Medicine, P.O. Box 334, Basseterre, St. Kitts, West Indies.
Stewart
S
Francis
Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70803, USA.
Michael T
MT
Kearney
U.S. Geological Survey, Western Fisheries Research Center, Seattle, WA 98115, USA.
John D
JD
Hansen
D000818:Animals; D017756:Aquaculture; D001426:Bacterial Proteins / Q000235:genetics; D018441:Biofilms / Q000254:growth & development*; D004202:Disinfectants / Q000494:pharmacology*; D005393:Fish Diseases / Q000382:microbiology; D005399:Fishes / Q000382:microbiology; D005603:Francisella / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D016905:Gram-Negative Bacterial Infections / Q000382:microbiology; D008826:Microbial Sensitivity Tests; D054712:Salinity; D013696:Temperature; D037521:Virulence Factors / Q000235:genetics
D001426:Bacterial Proteins; D004202:Disinfectants; D037521:Virulence Factors
Biofilm; Francisella noatunensis; Francisellosis