Antimicrobial Properties
of Garfish Blood
Rachel E. Laird
Nicholls State University
Antimicrobial Studies Involving Fish Blood
Rainbow trout (Oncorhynchus mykiss) model.
Hollebecq et al;1995; - complement blood plays a
significant role in defending against infection, the
bactericidal activity of the trout blood is more
accurate in defending against furunculosis.
Bandin et al.; 1995; - opsonized bacteria
increased their survival inside phagocytes
Nikoskelainen et al.;2002; - rainbow trout
complement activity increased from 10oC to 35oC
Why Gar Blood?
• There have been no studies to date on the
effects of gar blood on bacterial activity.
• Help gain a better understanding of garfish
biology.
• Establish a foundation to further explore
blood components of an ancient fish
species.
• Isolating and characterizing the molecules
would help aid in a better understanding of
host-pathogen interactions and pathways.
Background
Fish immune responses against bacteria involve
both cellular and non-cellular components
Complement and small antimicrobial peptides
are thought to be important innate immune
responses
Activity of blood is dependent upon such factors
as temperature.
Bayou Lafourche has 106 CFU/ml
Aerobic bacterial load (Nathaniel, R. unpublished)
Complement – series of enzymatic events
resulting in formation of a ‘membrane attack
complex, ‘death by a hole puncher’
Antimicrobial Peptides – cationic peptides,
5-60 aa, disrupt membrane integrity.
Objective:
To determine the antimicrobial
properties in Garfish Blood.
Hypotheses:
• Gar blood will have a bactericidal effect.
• Bactericidal effect will follow a dose
dependent and time dependent
mechanism.
Audubon Bridge Water Collection Point
Satellite Image of Mississippi Drainage Basin
Thibodaux
New Orleans
Houma
Methods
Bayou Lafourche Water
Serial dilutions
Control =
Medium + Bayou water
Test =
Medium + Bayou water
+ Blood
Blood Sterility Control =
Medium + Blood
All results incubated at 37°C for 18 hrs, OD600 readings taken
Bacterial Number CFU/ml
Bacterial Number CFU/ml
Effects of Gar Blood on Bacterial Growth
Bacterial Number (CFU/ml)
Mean Effects of Gar Blood on Bacterial Growth
N=4; *P<0.001
*
*
Bacterial Number CFU/ml
Effects of Gar Blood on Bacterial Growth over 24 Hours
N=6
Bacterial Number CFU/ml
Effect of Heat Treated Gar Blood on Bacterial Growth
Bacterial Number CFU/ml
Mean Effects of Heat Treated Gar Serum on Bacterial Growth
N=3
Summary
Gar blood (@10%) showed antimicrobial
activity against up to ~1,000 bacteria/ml
We did not yet find antimicrobial activity
to follow a time dependent mechanism.
We have not yet been able to show
antimicrobial activity to be heat labile.
Acknowledgements
Dr. Quenton Fontenot
Dr. Allyse Ferrara
Mr. Rickey Verrett (Gar Fisherman)
Ms. Olivia Smith
Dr. Rajkumar Nathaniel
Funded by:
LA Board of Regents