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.

BackgroundFish 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Bayou Lafourche has 106 CFU/ml Aerobic bacterial load (Nathaniel, R. unpublished)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

New OrleansThibodauxHouma

Satellite Image of Mississippi Drainage Basin

Methods

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

Serial dilutions

Bayou Lafourche Water

Effects of Gar Blood on Bacterial GrowthB

acte

rial

Nu

mb

er C

FU

/ml

Bac

teri

al N

um

ber

CF

U/m

l

Mean Effects of Gar Blood on Bacterial GrowthB

acte

rial

Nu

mb

er (

CF

U/m

l)

N=4; *P<0.001

*

*

Effects of Gar Blood on Bacterial Growth over 24 HoursB

ac

teri

al N

um

be

r C

FU

/ml

N=6

Effect of Heat Treated Gar Blood on Bacterial Growth

Bac

teri

al N

um

ber

CF

U/m

l

Mean Effects of Heat Treated Gar Serum on Bacterial GrowthB

acte

rial

Nu

mb

er C

FU

/ml

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 FontenotDr. Allyse FerraraMr. Rickey Verrett (Gar Fisherman)Ms. Olivia SmithDr. Rajkumar Nathaniel

Funded by:LA Board of Regents