Microbiology

A disease is a state in which there is a structural or functional abnormality of the body causing a disturbance of normal health.

Pregnancy

Genetics Autoimmune diseases Tumors and cancer Inflammation Malnutrition and obesity Pathogens Physical and Chemical agents

are disease-producing microbes including bacteria, viruses,fungi,protozoa

are multi-cellular worms and are often clearly visible to the naked eye such as tapeworms

A bacterium is a tiny, primitive cell without a nucleus some bacteria live harmlessly in the body making up normal flora

which and receive shelter and benefit the host by keeping potentially harmful microbes at bay.if they migrate to a different anatomical location, they can cause infection

this is where Bacteria are able to cause a disease

This is the extent to which they CAN cause a disease.refers to the degree of pathogenicity or the ability of a microorganism to cause disease in a host organism.

They cause infection only in people whose immune status is compromised by illness, drugs or the invasive procedures they have undergone (e.g. surgery, endotracheal intubation, IV access). They do not attack healthy tissues

Shape Staining Function

Bacilus - roldlike Coccus - spherical Vibrio spirillum, or spirochete - curved

Bacillus Diplobacillus Streptobacillus

Cocci are round bacteria. Monococcus Diplococcus

Clusters of cocci are termed staphylococci

Streptococci are round bacteria found in chains

Vibrio are curved rods

Spirochaetes are very small, flexible spirally shaped bacteria

Gram negative bacteria cannot retain the crystal violet stain, instead taking up the counter-stain and appear red or pink.

Aerobic bacteria need oxygen for their metabolism.

Anaerobic bacteria metabolise in the absence of oxygen

Secrete toxic substances that damage human tissues Become parasites inside human cells Form colonies in the body that disrupt the cell and ultimately disrupt normal human function.

• Gain access to the host tissue • Move to a favourable site • Multiply successfully in spite of the host defence mechanisms • Reproduce so new pathogens can be disseminated

Inhalation Ingestion skin and mucous membranes vertical transmission urogenital tract