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
THERMOPHILE
LIKES WARM TEMPERATURE
122-158 DEGREES F.
THREE FORMS OF MDRO
MRSA
VRE
CRE
MRSA
Methicillin-Resistant Staphylococcus Aureus (MRSA) –
Staphylococcus aureus bacteria that have developed a resistance to Methicillin, the drug of choice.
MRSA usually occurs in patients who have been on antibiotic therapy for a long time.
VRE
Vancomycin-Resistant Enterococcus (VRE)
Enterococcus bacteria that are no longer sensitive to Vancomycin. Transmission can occur by direct contact, or indirectly via the hands of personnel.
CRE
Carbapenum- Resistant Enterobacteriaceae (CRE)
Have high levels of resistance to the antibiotic carbapenem.
Klebsiella and Escherichia coli (E. coli are examples of Enterobacteriaceae.
CRE infections have been associated with devices such as flexible endoscopes, ventilator, urinary catheters or intravenous catheters.
SIZES OF BATERICA
Most bacterial cells are 1-2 microns in size.
A micron is 1/25,000 of an inch.
WHAT DO VIRUS NEED TO SURVIVE?
One of a group of minute infectious agents that only grow in living tissue or cells. (need a host to hijack).
Viruses are Tiny
Viruses are about 1000 times smaller than bacteria.
Ex. Smallpox, rabies, yellow fever, AIDS, influenza, Measles
The Virus itself has no means of movement and depends on air, water, insects, humans or other animals to carry it from one host to another.
TYPES OF HEPATITIS
- A is often implicated in foodborne illnesses.
- B, C, D, and E are transmitted in body fluids.
- There are vaccines available for A and B.
- Hepatitis B vaccine is strongly recommended for CST
- Hepatitis B virus HBV is the most prevalent chronic bloodborne infection today. (Along with Hep C and HIV)
WHAT HEPATITIS TEST IS RECOMMEND FOR CST’S
Hepatitis B virus
TWO TYPES OF SUPERFICIAL FUNGI
Attack mainly epidermis, hair, nails, and mucosal surfaces.
Ringworm and Athlete’s foot
