Production, characterization and evaluation of virulence of an adhesion defective mutant of Flavobacterium columnare produced by beta-lactam selection.
OBJECTIVE
The aim of this study was to develop and evaluate mutants of Flavobacterium columnare, the causative agent of columnaris disease in fish.


RESULTS
Serial passage on ampicillin (beta-lactam) enriched modified Hsu-Shotts medium resulted in a F. columnare mutant that differed from the parent strain in colony morphology, whole cell proteins, adhesion and virulence. The mutant differed from its parent in virulence during immersion challenge, but not during injection challenge or generation of antibodies.


CONCLUSIONS
Flavobacterium columnare exposure to ampicillin produces both resistance to that antibiotic and produces mutants that lack or have reduced adhesion characteristics and modified ability to adhere to fish tissue.


CONCLUSIONS
This is the first description of an adhesion-defective mutant of F. columnare and the effects of altered adhesion on columnaris disease. This mutant has considerable potential as a tool to study the role of adhesion in columnaris disease.
Bader
J A
JA
Aquatic Animal Health Research Laboratory, Agricultural Research Service, United States Department of Agriculture, Auburn, AL 36831-0952, USA. jbader@ars.usda.gov
Shoemaker
C A
CA
Klesius
P H
PH
D000667:Ampicillin / Q000494:pharmacology; D000818:Animals; D001422:Bacterial Adhesion / Q000235:genetics; D002397:Catfishes / Q000382:microbiology*; D003470:Culture Media; D005393:Fish Diseases / Q000382:microbiology*; D045826:Flavobacteriaceae Infections / Q000382:microbiology / Q000662:veterinary*; D005417:Flavobacterium / Q000187:drug effects / Q000235:genetics / Q000472:pathogenicity* / Q000502:physiology; D009154:Mutation; D010403:Penicillin Resistance; D012692:Serial Passage; D014774:Virulence / Q000235:genetics; D047090:beta-Lactams / Q000494:pharmacology
D003470:Culture Media; D047090:beta-Lactams; D000667:Ampicillin