bacillus thuringensis mode of action.pptx

To explore how bacteria interact with their environments and host organisms, and how they execute their biological functions.
Importance: Understanding bacterial modes of action is crucial for developing antibiotics, vaccines, and other medical interventions.

1. Understanding the Mode of Action of Bacteria Introduction Purpose : To explore how bacteria interact with their environments and host organisms, and how they execute their biological functions. Importance : Understanding bacterial modes of action is crucial for developing antibiotics, vaccines, and other medical interventions.

2. Basic Bacterial Structure and Function Structure : Cell Wall : Composed of peptidoglycan (in Gram-positive bacteria) or outer membrane (in Gram-negative bacteria). Cell Membrane : Phospholipid bilayer with embedded proteins. Cytoplasm : Contains genetic material (DNA), ribosomes, and other essential components. Flagella/ Pili : For movement and attachment. Function : Basic metabolic processes, replication, and protein synthesis.

3. 2. Bacterial Growth and Reproduction Binary Fission : The primary method of reproduction where a single bacterium divides into two identical daughter cells. Growth Phases : Lag Phase : Adaptation period. Log Phase : Rapid growth and division. Stationary Phase : Growth rate slows as resources are depleted. Death Phase : Decline in number due to nutrient depletion and waste accumulation.

4. 3. Mechanisms of Pathogenicity Adhesion : Fimbriae/ Pili : Help bacteria adhere to host tissues. Capsules : Protect bacteria from phagocytosis. Invasion : Enzymes : Such as hyaluronidase and collagenase, break down host tissues. Toxins : Exotoxins : Secreted proteins that can damage host cells (e.g., botulinum toxin). Endotoxins : Lipopolysaccharides in Gram-negative bacteria that can trigger systemic inflammatory responses.

5. . Mechanisms of Antibiotic Resistance Resistance Mechanisms : Enzymatic Degradation : Enzymes like beta-lactamase break down antibiotics. Efflux Pumps : Remove antibiotics from bacterial cells. Altered Targets : Changes in the antibiotic’s target site reduce binding. Reduced Permeability : Changes in membrane permeability prevent antibiotic entry. Genetic Basis : Plasmids : Extra-chromosomal DNA that can carry resistance genes. Mutations : Genetic changes in bacterial chromosomes.

6. 5. Interactions with Host Immune System Immune Evasion : Antigenic Variation : Changing surface proteins to avoid immune detection. Immune Suppression : Producing factors that inhibit immune responses. Host Responses : Innate Immunity : Includes barriers, phagocytes, and inflammation. Adaptive Immunity : Involves specific responses like antibody production.

7. 6. Applications and Implications Medical Treatments : Antibiotics : Development and challenges of antibiotic resistance. Vaccines : How vaccines target bacterial components to prevent disease. Biotechnology : Genetic Engineering : Using bacteria to produce proteins, drugs, and other substances. Environmental Impact : Bioremediation : Utilizing bacteria to degrade pollutants.

8. Conclusion Summary : Recap the key points on bacterial modes of action, including structure, pathogenicity, resistance, and interactions with the host. Future Directions : Ongoing research in combating antibiotic resistance and enhancing bacterial applications in medicine and industry.