Chapter 4 Microbiology Flashcards
Study Guide
WHAT IS MICROBIOLOGY?
Microbiology is the study of microorganisms. The scientific study of the nature, life and action of microorganisms.
WHAT IS CONTAMINATION?
Contamination is the state of being soiled or infected by contact with infectious organisms or other material.
WHAT IS PATHOGENIC?
Disease – producing = Microorganisms that can cause illness are called pathogens. Pathogens cause disease by producing powerful toxins that interfere with how body systems work.
Central Service Technicians protect patients from pathogenic organisms.
Pathogens are a specific concern for CS professionals, as disease-causing organisms can reside on the instruments and devices used in patient care, leading to healthcare-associated infections (HAIs)
WHY DO WE NEED MICROBES?
Not all Microorganisms are Harmful:
- Microbes are the basic unit of life
- Only 1% of bacteria are harmful.
- Microorganisms are everywhere and are necessary for our existence. 95% of bacteria are beneficial.
Microorganisms maintain the balance of chemical elements in the natural environment by breaking down dead matter and recycling carbon, nitrogen, sulfur and other elements.
WHAT ARE ENDOSPORES?
A microorganism capable of forming a thick wall around itself that enables it to survive in adverse conditions; a resistant form of bacteria. (need to be killed under the right parameter)
Spores are very resistant to disinfection and other conditions, such as heat, making them very difficult to kill.
PROCESS OF BACTERIA REPRODUCTION?
This process is called Binary Fission.
Binary Fission= Is the typical method of bacterial reproduction in which a cell divides into two equal parts.
HOW TO ID BACTERIA
(DIFFERENT SHAPES)
Bacteria are divided into 3 main groups by shape:
- Round (Cocci) or spherical shaped and occur in pairs, clusters, or chains.
- Rods (Bacilli) may be large and brick-shaped or small and stick-like.
- Spirals (Spirillum) vary from comma-shaped to longer bacteria with many twists.
COCCI (Round)
Ex. Staphylococcus Aureus
Where are they found?
In our nose and skin (Normal flora)
Causes: Abscess, boils, sepsis.
BACILLUS (Rods)
Ex. Pseudomonas aeruginosa
Where are they found:
Found in soil, water, skin flora
Causes: Pneumonia and urinary tract infections.
Spirillum (Spirals)
Ex. Helicobacter pylori
Where are they found:
Found in contaminated food and water
Causes: Stomach ulcers, gastritis
About 50% of the world population is estimated to have detectable H. Pylori in their gastrointestinal tract (But mainly in the stomach)
GRAM STAIN
(POSITIVE)
Gram Stains Purple = (Gram positive)
GRAM STAIN POSITIVE BACTERIA= Have no outer membrane and will retain the purple stain, even if a decolorizer is used.
GRAM STAIN
(NEGATIVE)
Gram Stains Pink= (Gram Positive)
GRAM STAIN NEGATIVE BACTERIA= Have an outer membrane that will not retain the purple stain after treatment with iodine; they will stain pink.
ZIEL NELSON STAIN
(ACID FAST STAIN)
Ziel Nelson Stain (acid-fast stain) – Stains bright RED. Done to detect Mycobacteria (causes TB)
ZIEL NELSON STAIN (ACID-FAST STAIN) = Some acid-fast bacilli are rod-shaped and are very difficult to stain, but once stained and heat or other agents are used, the bacteria will resist decolorization with a dilute acid-alcohol solution.
BACTERIA THAT DON’T NEED OXYGEN
Anaerobic Bacteria
Capable of growing in the absence of free oxygen. Does not Require Oxygen
BACTERIA THAT NEEDS OXYGEN
Aerobic Bacteria
Capable of growing in the presence of free oxygen. Requires Oxygen.
3 TYPES OF BACTERIA
PSYCHROPHILES
MESOPHILES
THERMOPHILE
PSYCHROPHILES
LIKES COLD TEMPERATURES
59-68 DEGRESS F.
MESOPHILES
LIKES MODERATE TEMPERATURES
68-113 DEGREES F.
MESOPHILES ARE THE BACTERIA MOST PATHOGENIC TO HUMANS
