Introduction to Microbiology

Introduction

Microbes are ubiquitous (everywhere)Friends & EnemiesOf great importance to healthcare

What is Microbiology

The study of microbesorganisms that must be viewed with a microscope... viruses, bacteria, protozoa, archae, and some algae, helminths and fungi

Relative sizes of microbes

Microbes (cont.)

microbes may be classified as cellular or acellular (viruses & prions)

most are harmless, but ~3% are pathogens (cause disease)

Impact of infectious diseases caused by pathogenic microbes

Microbes and Humans

We are made up of about 1 trillion cells.

At any point in time you have about 10 trillion microbial cells growing on or inside you.

Microbes on us...

the microbes living on or in us are referred to as our indigenous microflora

some are opportunistic pathogens (can potentially cause harm)

Importance of Microbes

Bioremediation - "Remediate" means to solve a problem,

and "bio-remediate" means to use biological organisms to solve an environmental problem such as contaminated soil or groundwater.

Genetic engineeringNutrient cyclingFood webs diagram of the links among species in an ecosystem –

essentially who eats what. A food chain shows only the organisms that contribute to the diet of the top consumer

BiotechnologyAntibiotic productionDisease

The First Microbes

Earliest known infectious diseases

Early human fossils & organs from mummies show evidence of TB, syphilis, schistosomiasis, and tapeworm infection

1900 BC, Greek army decimated by Bubonic Plague

1122 BC China was ravaged by smallpox

Pioneers in Microbiology

Anton von Leeuwonhoek

father of: microbiology, bacteriology, protozoologyinvented a simple microscope to observe microbes

Robert Hooke

Contemporary/ collaborator of Leeuwenhoek

Developed the compound microscope

Wrote “Micrographia” on observations

Coined the term “cell”

Louis Pasteur

Developed pasteurization

Developed the germ theory

Pioneered vaccinations

Promoted hospital practices to minimize disease spread

Robert Koch

Developed postulates for linking disease with a particular pathogen

1st demonstration of bacterial caused disease

Anthrax; Bacillus anthracis; (Gr., coal)-refers to the "black" blood in killed, diseased animals

cattle and sheep graze in infected pastures

anthrax spores (resistant form of bacteria) are in soil enter bloodstream via mucosal abrasions

Animals are very ill, weak, swollen, have black, bloody discharges

Animal dies and is buried earthworms pick up spores and carry them to the surface dirt animals graze in infected pastures, etc.

CONTROL: bury animals at a depth of at least 6 feet (no earthworms this deep)

FIRST DEMONSTRATION OF BACTERIAL DISEASE: 1876- Robert Koch

1. The suspected microorganism is present in every case of the disease and absent from healthy animals.

2. One must isolate and grow the microorganism in pure culture.

3. Injection (infection) of a healthy host with the microorganism in pure cultures must cause disease.

4. One must be able to isolate the microorganism from the new host.

Koch’s postulatesKoch’s Postulates

1. not all pathogens thrive in lab culture,

2. some are species specific,

3. some are synergistic,

4. some become less pathogenic when grown in vitro

Exceptions to Koch’s Postulates

Careers in Microbiology

Medical Microbiology involves the study of pathogens and the diseases they cause, as well as how the body fights those diseases

Clinical Microbiology deals mainly with the diagnosis of infectious diseases

Soil and Plant Microbiology deals in a variety of settings including microbial ecology, soil microbiology, environmental microbiology and plant pathology.

Employment Opportunities

Where do Microbiologists work?Microbiology positions include:Federal and State governmental laboratories (Center for Disease

Control, Food and Drug Administration, USDA, Dept. of Energy, etc.)Private environmental consulting companiesPharmaceutical industryFood production specialistFood safety and clinical laboratoriesHealthcare industryState laboratoriesBeginning salaries range from $40,000.