Applied Microbiology Lecture 1

Applied Microbiology Lecture Notes

Understanding Microorganisms

• Definition of microorganisms: Generally too small to be seen without tools. Explore various groups including bacteria, archaea, eukaryotes, and viruses.

• Opportunistic pathogens: 10% of microbes are opportunistic; only 3% are pathogenic.

Importance of Microbes

• ** ubiquity of microbes:** Found in various habitats including soil, water, and human bodies.

• Role in health and disease: Microbes have significant health impacts; understanding them is crucial for studying infectious diseases and health interventions.

Microbiology's Impact on History and Society

• Historical examples: There are many ways that microbiology has shaped human history, such as the bubonic plague and the development of vaccines.

• Contemporary issues: Discuss the importance of addressing superbugs and antibiotic resistance issues as highlighted by the WHO.

Key Microbiological Techniques

• Koch's postulates: Used to establish causative links between pathogens and diseases.

• Microscopic Techniques: Understanding various microscopy techniques like bright-field, phase contrast, dark field, fluorescence, transmission electron microscopy (TEM), and scanning electron microscopy (SEM).

Microscopy Techniques

Light Microscopy

• Bright-field: Commonly used, requires appropriate lighting for viewing living samples.

• Phase Contrast: Enhances contrast in transparent specimens.

• Dark Field: Produces bright images on a dark background for viewing live cells.

• Fluorescence Microscopy: Allows visualization of specific proteins or molecules by tagging them with fluorescent dyes.

Electron Microscopy

• Transmission Electron Microscopy (TEM): High-resolution imaging that requires thin specimens due to electron absorption.

• Scanning Electron Microscopy (SEM): Provides surface details and 3D images of samples.

• Differences in microscopy methods: Light microscopes utilize glass and visible light, whereas electron microscopes run on electron beams and magnetic lenses.

Practical Skills

• Focusing microscopes: Students should practice bringing specimens into focus across different magnifications.

• Understanding working distance: The distance required to bring a specimen into focus significantly varies between objectives.

Key Terminology

• Species vs. Strains: Understanding the classification of microorganisms.

• Horizontal Gene Transfer: Mechanism by which bacteria increase genetic diversity beyond sexual reproduction.

Conclusion of Lecture One

• Recap of key concepts covered: Discussed microbial classification, Koch's postulates, and microscopy methods.

• Student engagement and questions are welcomed: Encouragement to seek clarification and explore deeper concepts as lectures progress.