INTRODUCTION Vibrio fischeri Hawaiian Bobtail Squid

Introduction

Life style

Vibrio fischeri V. harveyi

The bacteria exist as free-living cells or as symbionts in the light-producing organ of theHawaiian bobtail squid. Thehost provides a nutrient rich environment for the bacterium and the bacterium provides light for the host.

LIGHT OFF LIGHT ON What do you figureout from this?? Bacteria tell the difference when they are alone Vs They are in mass

“I think that a multiple of bacteria are stronger than a few and thus by union are able to overcome obstacles too great for the few”. (Smith 1905)

At high cell concentrations, the level of the autoinducer becomes sufficient to induce transcription of the genes that produce the enzyme luciferase, leading to bioluminescence

The signal molecules??

C. Auto inducer 2 (AI-2) A,B. Acyl Homoserine Lactone

virulence genes expression

Why are the signals important for??

They exhibit complex cooperative behaviours, such as – Antibiotic resistance, – conjugal plasmid transfer, – biofilm formation – virulence, etc

Eventhough some bacterias can be effectively controlled by antibiotics, most of them talk to discover novel strategies not to be killed by antibiotics.

Uh! What should we do??

-Halogenated furanone secreted by red marine algae. -marine natural products. -food such as garlics, honey and plant based products.

What National significance does this study has?? Antibiotics are commonly used for the treatment of bacterial infections. The inappropriate and indiscriminate application of antibiotics in pharmacotherapy has led to the development of widespread resistance to these agents.

Multi antibiotic resistant bacteria are emerging spreading out of control nowadays. It is becoming more & more difficult to treat bacterial infections with currently available antibiotics.

CONCLUSION AND RECOMMENDATIONS