Chapter 7: Microorganisms and Infection Control Flashcards
Microorganisms
An extremely small life form, only able to be seen with a microscope
Infection
The invasion and multiplication of harmful microbes with the body’s tissues
Types of Microorganisms
1) Bacteria
2) Viruses
3) Fungi
4) Protozoa
5) Prions
Bacteria
Single-celled microorganisms, widely dispersed in nature
Most are harmless, and some are capable of causing disease
Gram Staining
The procedure for identifying bacteria and certain other microbes according to their reaction to the dye
Either Gram Positive (stains blue/purple) or Gram Negative (stains pink/red
Staphylococcus aureus
A Gram positive bacteria, frequently cause blepharitis, conjunctivitis and keratitis
Methicillin-Resistant Staphylococcus aureus (MRSA)
A S. aureus bacteria that is resistant to most antibiotics
Pseudomonas aeruginosa
A Gram negative bacteria, often seen with over use of contact lenses. Can result with permanent vision loss within 48 hours.
Neisseria gonorrhoeae
A Gram negative bacteria that is typically transmitted through sexual activity or exposure through birth
Mycobacteria
A bacteria capable of intracellular growth, was once common with LASIK surgery
Chlamydia trachomatis
A bacteria responsible for neonatal conjunctivitis, inclusion conjunctivitis, trachoma
Treponema pallidum
The bacteria responsible for Syphilis
Borrelia burgdorferi
The bacteria responsible for Lyme Disease
Virus
A microorganism smaller than the smallest bacterium that has no cellular structure and can cause infectious disease
Many viruses have a finite, definitive course that they run.
Treatment is aimed at alleviating symptoms
Herpes Virus
A family of viruses
Herpes Simplex virus Type 1
A herpes virus that causes recurrent fever blisters on the lips and mouth, and can cause keratitis
Herpes Simplex virus Type 2
A Herpes virus that causes fever blisters on the genitals and is spread through sexual contact
Varicella-zoster virus
A herpes virus that produces chicken pox, shingles, and herpes zoster ophthalmicus
Herpes zoster ophthalmicus
A condition in which the varicella zoster virus that can cause painful blistering rash that involves the forehead, eyelids, uveitis, corneal inflammation, and more
CMV Retinitis
An ocular infection due to Cytomegalovirus, common in HIV patients
Cytomegalovirus
A member of the herpes virus family that can cause CMV retinitis
Human Immunodeficiency Virus (HIV)
A retrovirus that causes AIDS, a disorder of the immune system that increases the patient’s susceptibility to infections
Adenovirus
A family of viruses involved primarily in respiratory infections, but can also cause highly contagious conjunctivitis (Viral Pink Eye)
Fungus
A multi-celled microorganism that differs from bacterium in that it has a more complex structure
Includes yeast and mold
Ocular infections are typically due to trauma with vegetative matter
Yeast
A form of fungus that produces creamy or pasty colonies
Mold
Aa form of fungus that produces wooly, fluffy, or powdery growth
Candida albicans
A type of fungus (yeast) commonly found on the body that can cause opportunistic infections
Histoplasma capsulatum
A type of fungus (mold) that is commonly found in soil and in animal droppings in certain areas of the US. Capable of causing mild to life-threatening infections
Protozoans
A large, single-celled microbe found in fresh and salt water, soil, plants, insects, and animals
Acanthamoeba
A free-living amoeba, commonly found in water.
Can cause keratitis, and is most commonly seen in contact lens wearers with poor hygiene habits
Toxosplasma gondii
A Protozoan responsible for Toxoplasmosis infections
Toxoplasmosis
A infection caused by Toxoplasma gondii, which can cause lesions in the retina and brain
Prions
Extremely small pathologic protein elements responsible for brain disorders that occur in certain animals
EX: Mad Cow Disease or Laughing Disease
Transmission of Infectious Disease
1) Airborne
2) Direct contact with contaminated individual
3) Indirect contact
4) Common-vehicle Transmission
5) Vector borne
Reservoir
An inanimate or animate object that provides a microorganism the means for survival and opportunity for transmission
Host
The animal or plant from which a microbe gains nutrients and the conditions necessary for its survival and reproduction
Airborne Transmission
The transfer of microbes through a water droplets that have been produced through someone sneezing or coughing
Direct-Contact Transmission
The form of infection transmission between people usually requiring body contact, or contact with blood/body fluids
EX: Hand shaking
Indirect-Contact Transmission
The form of infection transmission involving an intermediate, inanimate object
EX: Touching an infected doorknob
Common-Vehicle Transmission
The form of infection transmission involving the transfer of infectious microbes from one reservoir to many people
EX: Using an eyedrop bottle that has been contaminated on many people
Vector-Borne Transmission
The form of infection transmission involving the transfer of infectious microbes from a vector (organism) to another host
EX: Rabies
Infection Control Precautions
A series of protocols designed to prevent the spread of infection
Universal Precautions
An approach to infection control in which all human blood and certain human bodily fluids are treated as if known to be infectious for HIV virus, Hep B virus, or other blood borne pathogens. This approach is based on the concept that a medical history and examination cannot reliably identify all patients infected (or potentially infected) with a blood borne pathogen, so care of all patients should include these precautions.
EX: Hand washing, gloves, masks and goggles
Standard Precautions
A program of sanitation and microbial control in the medical office, intended to reduce the opportunity for harmful microbes to flourish and threaten patients and medical personnel.
Includes universal precautions and body substance isolation precautions.
Disinfection
The process of inactivating or eliminating pathogenic microorganisms
Germicide
A chemical that kills germs
Steriliation
A process that utilizes heat or chemicals to destroy all living or dormant microorganisms
Sterilization Methods
Dry heat, Moist heat, and Ethylene Oxide
Autoclave
A metal chamber equipped to use steam of gas under high pressure and temperature to destroy microorganisms
Aseptic Technique
A range of procedures used in medical environments to prevent the spread of infectious microbes
Empiric Treatment
The institution of medical treatment based on probable cause, before test results or time-consuming procedures confirm a diagnosis
Any samples or specimens should be collected before beginning treatment, so as not to interfere with test results.
