Microbial Diversity - Prelim II

Microbial Diversity

• The variety of Different types of microbes in the environment

Acellular

What type of Organism is a Virus?

10-300 nm

The average size of a Virus

Capsid

• An outer shell made up of proteins to protect the genetic material of a virus

Capsomeres

• protein subunits that assemble to form a capsid

Enveloped Virus

• Virus having an extra outer layer composed of lipids and polysaccharides and are less resistant to extreme enviroments

Non-enveloped Virus

• No extra outer layer but are more resistant to extreme pH, heat, dryness, and simple disinfectants

Pathogenicity

• organism’s ability to cause disease

Virulence

• refers to the severity of the disease that the pathogen cause

Type of genetic material, capsid shape, number of capsomeres, capsid size, presence and absence of envelope, type of host it infects, type of disease it produces, target cell, immunologic or antigenic properties

The 9 characteristics of Viruses

Bacteriophage

Types of Viruses

• Viruses that infect bacteria

Virulent and Temperate

• the two types of Bacteriophage

Virulent Bacteriophage

• also known as lytic phages and end with immediate destruction to bacterial cell

• complete process takes less than an hour

Temperate Bacteriophage

• also known as lyosogenic phages

• do not immediately cause lysis, instead, viral genetic information stays dormant and integrates into the bacterial genetic information generation after generation

Animal viruses

Types of Viruses

• viruses that infect animals and humans

Enveloped

Multiplication of Animal Viruses

• enters through membrane fussion

Non-enveloped

Multiplication of animal viruses

• enters through endocytosis (cell takes in materials from the external environment)

Exocytosis, Budding, Cell Rupture

3 types of Release of Viruses in Animal Viruses

Latent Viruses

Types of Viruses:

• a virus that hides within a hose cell and remains inactive

Oncogenic Viruse

Types of Viruses:

• viruses that cause cancer

Mimivirus and Megaviruse

Types of Viruses:

• that mimic bacterias in terms of size and staining properties

Plant Virus

Types of Viruses:

• viruses that targets plants which resulted to huge economic losses and are usually transmitted through insects, worms, and farming tools

Human Immunodeficiency virus

Types of Viruses:

• virus that causes acquired immunodeficiency syndrome (AIDS) and invade helper T cells and macrophage

Antiviral Agents

• pharmaceutical agents administered in the presence of viral infection

Viriods

• only made of single-strand cellular RNA without a coating

• plant-infecting pathogents

Self-cleaving

How do viroids multiply?

Virion

• complete form of a virus outside a host cell

Prions

• tiny infections (misfolded) proteins that cause fatal neurological diseases in humans and animmals

Spongiform Encephalopathies

• accumulation of misfolded proteins cause death to nerve cells leaving behind empty spaces in the brain