Chapter 18: Microbiology pt.2 Flashcards
What is the first criteria of Koch’s Postulates
the microbial agent must be found in every case of the disease.
What is the second criteria of Koch’s Postulates
The microorganism must be isolated and grown in pure culture.
What is the third criteria of Koch’s Postulates
The microorganism must cause the same disease when inoculated into a susceptible animal.
What is the fourth criteria of Koch’s Postulates
The same microbial agent must be recovered from the inoculated animal.
Who is referred to as the “Father of Microbiology”?
Louis Pasteur (1822-1895)
Who recognized that airborne microorganisms were responsible for post surgical infections?
Joseph Lister (1827-1912)
Who was responsible for discovering the rabies vaccine?
Pasteur
Why is microbiology important to the dental assistant?
it helps them understand the way pathogens work and how to prevent the spread of disease through infection control.
What are the three primary shapes of bacteria?
Spherical (cocci), Rod (bacilli), Spiral (spirochetes)
What is the staining process for separating bacteria?
Gram positive They appear dark purple under the microscope, Bacteria found on the slide and appear pink or red means there is a Gram-negative infection, Bacteria that are not consistently stained are classified as Gram variable .
What is the term for bacteria that require oxygen to grow?
Aerobes
What is the most resistant form of bacterial life?
spores
How are prions different from other microorganisms?
Prions convert normal protein molecules into dangerous ones simply by causing the normal ones to change their shape
What is viral hepatitis?
inflammation of the liver caused by a virus
What are the symptoms of viral hepatitis?
Tiredness, Loss of appetite, Nausea, Abdominal discomfort, Dark urine, Clay-colored bowel movements, Yellowing of the skin and eyes (jaundice)
How long can HAV survive outside the body?
HAV can live outside the body for months, depending on environmental conditions.
How long can HBV survive outside the body?
HBV can survive outside the body for at least 7 days and still be capable of transmitting infection.
How long can HCV survive outside the body?
HCV can survive outside the body and continue to transmit infection for 16 hours, but not longer than 4 days.
How long is the HBV vaccine effective?
at least 15 years
Are booster doses of the HBV vaccine needed?
No, booster doses of the vaccine are not recommended routinely.
Which types of hepatitis are spread by exposure to blood?
Hepatitis B, C, and D
How is HIV spread?
sex, sharing needles with infected people, contaminated blood, mother to fetus
What tissues are affected by the West Nile virus?
Nervous system causing inflammation of the brain and spinal cord
How is the H1N1 virus spread?
When a person touches something contaminated with the virus then touches the eyes, nose, or mouth before washing hands
How is the Ebola virus spread?
The Ebola virus is spread through direct contact with blood and body fluids of a person who is sick with Ebola.
How is the Zika virus spread?
bites of mosquito; virus may persist in semen so also can be sexually transmitted
What birth defect can be caused by the Zika virus?
microcephaly
What microorganism is used as the benchmark for the effectiveness of a surface disinfectant?
Tuberculosis
What is a sign of the first stage of syphilis?
Painless ulcerating sore known as a chancre.
What disease is also known as lockjaw?
tetanus
What is a pandemic?
worldwide epidemic
microorganisms
a microscopic organism, especially a bacterium, virus, or fungus.
Algae
protosynthetic creatures found in freshwater and marine habitats. do not cause humans disease.
Antony van Leeuwenhoek (LAY-vuhn-hoak) (1632-1723)
He used a primitive microscope to observe stagnant water and scrapings from the teeth.
John Tyndall (TIN-duhl) (1820-1893)
was an English physicist who explained the need for prolonged heating to destroy microbial life in broth. He discovered that bacteria existed in heat-stable and heat-sensitive forms. Prolonged or intermittent heating was needed to destroy the heat-stable form
Ferdinand Cohn (1828-1898)
described the heat-stable forms as endospores , which are formed during the life cycle of certain bacteria
Joseph Lister (1827-1912)
an English surgeon who recognized the role of airborne microorganisms in postsurgical infection. By applying carbolic acid to dressings and using an aerosol of carbolic acid during surgery, he lowered the risk for infection after surgery
Robert Koch (1843-1910)
He developed a two-part dish that was used for growing bacteria and a technique used for isolating pure colonies of bacteria
Julius Petri (1852-1921)
the two-part dishes were named Petri plates after him. Petri plates are still used in microbiology laboratories today. To prove that a specific microorganism caused a particular disease
Louis Pasteur (1822-1895;)
disproved the theory of spontaneous generation of life and associated living microorganisms with disease.
How do spores survive?
Bacteria remain alive in the spore form but are inactive. As spores, they cannot reproduce or cause disease. When conditions are again favorable, these bacteria become active and capable of causing disease
why are spores important in dentistry?
Because of this incredible resistance, harmless spores are used to test the effectiveness of techniques used to sterilize dental instruments
Two diseases caused by Prions
Creutzfeldt-Jakob disease and Alzheimers
Diseases caused by bacteria
Lyme disease, tetanus, tuberculosis, diptheria, meningitis, strep throat, and tooth decay.
Diseases caused by viruses
Common cold, influenza, smallpox, warts, AIDS, chickenpox, measles, hepatitis, west nile, polio.
Hepatitis A “Viral hepatitis”
Inflammation and infection of the liver from the hepatitis virus. There is weakness, anorexia, nausea, fever, dark urine, and jaundice.
Hepatitis B Virus (HBV)
virus that causes inflammation of the liver; transmitted through any body fluid, including vaginal secretions, semen, and blood
Hepatitis B Virus (HBV)
virus that causes inflammation of the liver; transmitted through any body fluid, including vaginal secretions, semen, and blood
Hepatitis C Virus (HCV)
a blood-borne disease that is spread through contact with blood and other body fluids that are contaminated with this virus. it is describes as a silent epidemic because it can be present in the body for years, and destroy the liver, before any symptoms appear. there is no vaccine available
Hepatitis D virus (HDV)
a blood-borne disease that only occurs as a co-infection with B infection. although there is no specific vaccine, the hepatitis b vaccine should be given to prevent a HBV/HDV co-infection
Hepatitis E Virus (HEV)
a virus that is transmitted through the oral-fecal route and causes a form of hepatitis
Methods of HIV transmission
sexual contact, blood to blood contact, sharing of needles, from mother to child
the effect of HIV on the human body
it infects special T cells and slowly kills them. T cells have special receptors on their surfaces and are primarily responsible for immunity. As more and more T cells die, the body’s ability to fight infection weakens.
Herpes Simplex Virus (HSV)
an infection that manifests with painful, watery blisters on the skin and mucous membranes
Herpes simplex virus type 1
transient viral vesicles that infect the facial area, especially the mouth and nose
herpes simplex virus type 2
sexually transmitted, ulcer-like lesions of the genital and anorectal skin and mucosa; after initial infection, the virus lies dormant in the nerve cell root and may recur at times of stress
Herpes zoster virus (HZV)
This virus causes chicken pox and shingles. Chicken pox is the primary infection and shingles is its reactivation. Transmission occurs through direct contact with skin lesions or contact with infectious saliva. Herpes zoster is highly contagious to those who have not been previously infected.
Cytomegalovirus (CMV)
herpes-type virus that usually causes disease when the immune system is compromised
Epstein-Barr virus (EBV)
acute infection which causes sore throat, fever, fatigue, and enlarged lymph nodes; also called mononucleosis
