Microbiology Basics

MICROBIOLOGY BASICS

Disease is a failure of the body to function normally. There are many types of diseases, not all caused by germs. These include inherited diseases, diseases caused by birthdefects, age-related degenerative diseases, diseases caused by nutritional deficiencies, tumors, and diseases related to trauma and environmental toxins.
A leading cause of disease in humans is theinvasion of the body by pathogens, or disease-producing microorganisms. The invasion of the body by a pathogen and the symptoms that develop in response to this invasion are called an infection. Alocalized infection is restricted to a small area, whereas a systemic infection is more widespread.

TYPES OF PATHOGEN
The groups of microorganisms (some of which are pathogens) are bacteria, viruses,fungi, and protozoa. Other larger, disease-causing organisms include worms and arthropods
BACTERIA. Are single-cell organisms found everywhere. Most bacteria consider living conditions within the humanbody to be ideal, so they move right in. normal flora: prevents the overgrowth of other organisms, keeping them under control. Bacteria are classified into three groups based on
shape: (1) coccus(round); (2) bacillus (rod-shaped); and (3) curved rod.
RICKETTSIA And chlamydia are classified as bacteria. They are called parasites. The rickettsiae are often carried by fleas, ticks, and body lice.VIRUSES. Are the smallest of the infectious agents. They are not cells and consist of either ribonucleic acid (RNA) or deoxyribonucleic acid (DNA) surrounded by a protein shell.
FUNGUS Is aplantlike organism, such as a mushroom, which grows best in dark, damp places. Pathogenic fungi cause mycotic infections. Mycotic infections are usually localized and include athlete’s foot, ringworm, thrush(in the mouth), and vaginitis. Systemic fungal infections are rare, but when they do occur, they are life threatening and diffi cult to cure.
PROTOZOA. Are single-cell, animal-like microbes. The...