Chapter 18 & 19 Review

”Microbiology is the study of microorganisms

Louis Pasteur’s ongoing contributions to the emerging germ theory of disease earned him the title “Father of Microbiology.”

Pasteur saved the French wine industry by showing that vats of spoiled wine contained acid-producing bacteria

The four major groups of microorganisms are (1) bacteria, (2) protozoa, (3) fungi, and (4) viruses, with two additional groups; rickettsia and algae, that are less aggressive to humans

Bacteria

Bacteria can be seen to have three shapes: (1) spherical (cocci), (2) rod (bacilli), and (3) spiral (spirochetes)

Bacilli (singular, bacillus) are rod-shaped bacteria

Bacteria that are stained by the violet dye due to the thick layer of peptidoglycan in their cell walls are classified as Gram-positive.

Bacteria that do not hold the violet stain appear pink to red due to the thinner peptidoglycan wall and are classified as Gram-negative

Bacteria that are not consistently stained are classified as Gram variable.

Aerobes are a variety of bacteria that require oxygen to grow.

Anaerobes are bacteria that grow in the absence of oxygen and are destroyed by oxygen.

Spores- Under harsh environmental conditions, some bacteria change into a highly resistant form called spores, to protect themselves.

Protozoa (singular, protozoon or protozoan) consists of single-cell organisims that have a complex internal structure, and are either free-living or as parasites. They do not have a rigid cell wall.

Fungi lack chlorophyll, the substance that makes plants green. Fungi are not green.

Candida is a common yeast found in the oral cavity

Oral candidiasis is caused by the yeast Candida albicans.

Virus

Viruses can live and multiply only inside an appropriate host cell.

Symptoms of viral hepatitis?

Tiredness

• Loss of appetite

• Nausea

• Abdominal discomfort

• Dark urine

• Clay-colored bowel movements

• Yellowing of the skin and eyes (jaundice)

HBV can survive outside the body for at least 7 days.

The HBV vaccine is considered safe for pregnant women.

HIV

HIV infection is a blood-borne viral disease in which the body’s immune system breaks down.

Herpes simplex virus type 1 is a viral infection that causes recurrent sores on the lips. It’s now commonly known as fever blisters or cold sores.

HZV (human herpesvirus type 3) causes both varicella (chickenpox) and herpes zoster (shingles). Chickenpox is the primary infection, and zoster represents reactivation of the illness.

Types of Influenza 1) Seasonal (or common) flu 2) H1N1 (or swine) flu 3) Pandemic flu

Bacterial disease

Tuberculosis, which is caused by the bacterium, Mycobacterium tuberculosis.

The first stage of syphilis is characterized by the presence of a painless ulcerating sore, known as a chancre.

Prions are defined as “small proteinaceous infectious particles,”

Chain of Infections includes the following

1.      Number of micro-organisms/pathogens

2.      Virulence strength of micro-organisms

3.      Susceptibility (immune system) of the host

4.      Portal of entry

Virulence means the degree of pathogenicity or the strength of that organism in its ability to cause disease.

An infectious disease is one that is communicable or contagious.

Spatter consists of larger droplet particles that are contaminated by blood, saliva, and other debris (e.g., calculus, tooth particles).

Parenteral means through the skin, as with cuts or punctures. can occur through needle stick injuries, human bites, cuts, abrasions, or any break in the skin.

Parenteral transmission also called Percutaneous

Fecal-oral transmission occurs most often among healthcare and daycare workers (who frequently change diapers) and among careless food handlers.

A latent infection is a persistent infection in which the symptoms “come and go.”

Immunity allows the body to resist disease and prevents foreign bodies from causing infection.

When immunity is present at birth, it is called inherited immunity.

Immunity that is developed during a person’s lifetime is called acquired immunity. Acquired immunity can occur naturally or artificially.

The body then forms antibodies in response to the vaccine, resulting in artificially acquired immunity.

Universal Precautions is to treat every patient as if they are infected with a blood borne disease.

Standard Precautions, which is to protect healthcare providers from pathogens from blood, and body fluids (including saliva).

Droplet infection affects mucosal surfaces of the eyes, nose, and mouth. It can occur when the dental team member inhales aerosol generated by the dental handpiece.

Community to dental office to patient waterborne organisms colonize the inside of dental unit waterlines and form biofilm.

BBP defines an occupational exposure.

Hand hygiene is a term that applies to handwashing, use of an antiseptic hand rub, or surgical hand antisepsis. Hands must be washed before putting on gloves and immediately after the removal of gloves.

Always use liquid soap during handwashing.

Hand hygiene guidelines- First wash 20-30 seconds, in between patient wash 10 seconds.

Alcohol-based hand rubs are not indicated if your hands are visibly soiled or are contaminated with organic matter, such as blood or saliva.

Personal protective equipment (PPE) must be worn whenever you are performing tasks that could produce splash, spatter, aerosol, or other contact with body fluids.

Examples of PPE include protective clothing, surgical masks, face shields, protective eyewear, disposable patient treatment gloves, and heavy-duty utility gloves.

Your PPE is placed in the reverse order of what you change most frequently throughout the day. Gloves are changed most often, face protection less often

A mask is worn over the nose and mouth to protect the person from inhaling infectious organisms spread by the aerosol spray of the handpiece.

N95 filtration must be between 3-5 μm.

Different types of gloves used in a dental office.

Gloves may be the most critical personal protective equipment.

Medical examination gloves are usually vinyl or nitrile (latex-free) and are often referred to as “examination gloves” or “procedure gloves.”

Overgloves also known as “food handler gloves,” are made of lightweight, inexpensive, clear plastic.

Sterile gloves, used in hospital operating rooms, should be worn for invasive procedures involving the cutting of bone or significant amounts of blood or saliva, such as oral surgery or periodontal treatment.

Utility gloves are not used for direct patient care. Utility gloves are worn (1) when the treatment room is cleaned and disinfected between patients, (2) while contaminated instruments are being cleaned or handled, and (3) for surface cleaning and disinfecting

The use of natural rubber latex gloves has proved to be one of the most effective means of protecting the dental worker and the patient from transmission of disease. However, increased use of latex gloves and other products that contain latex in the dental office and other healthcare settings has created other problems.

Three common types of allergic reactions to latex have been identified. Irritant dermatitis involves only surface irritation. Type I and type IV allergies involve an immune reaction.