The Nature of Microorganisms

Ch.12 Unit 1

Surrounded by Microorganisms

• In the air

• On our skin

• In our food

• Things we touch

• Disease causing microorganisms are pathogenic

Nonpathogenic Organisms

• “good” organisms– Used to make buttermilk– Ferment grain to produce alcohol– Make bread rise– “breakdown” or decompose matter

• In the human body they work in the digestive system

• Help control growth of pathogenic organisms

Pathogenic

• “disease-causing”– Several types

• Bacteria• Viruses• Protozoa• Fungi• Rickettsiae (parasites)

Escherichia coli “E-coli”

• May cause food poisoning even death– lead to bloody diarrhea and abdominal cramps and in

some cases may cause kidney or renal failure and death. 

• Occurs when bacteria from the colon comes in contact with meat during the butchering process

» Can also occur when people use the restroom and don’t wash hands, then touch food

• Can be prevented by cooking meat to 160 and washing hands

Salmonella

• Can cause food poisoning or death

• Occurs from eating undercooked chicken or foods containing raw meat

• Can also be spread when food servers do not wash hands or utensils or area after working with chicken or eggs

Bacteria

• Several diseases caused by bacteria

• Classified by shape and arrangement

cocci- spherical or oval bacteria

• staphylococcus: cocci arranged in irregular, often grape-like clusters

• streptococcus: cocci arranged in chains

Bacilli are rod-shaped bacteria

• Escherichia coli • Streptobacillus

spirochete: a thin, flexible spiral

• Syphilis is a spirochete

Bacteria Cont.• Staph and Strept are everywhere in the

health care setting.– Staph can have serious impacts on patients,

usually seen in pts with low immune systems or newborns (can cause babies to die).

– Starts off as pimple looking

• http://www.sciencefriday.com/videos/watch/10043

http://www.evtv1.com/player.aspx?itemnum=14883

Bacteria Needs to grow.

• Food

Bacteria Need

• Moisture

Bacteria Need

• Temperature– 170 kills most bacteria– 50-110 bacteria love! Grow rapidly– 32 low temps do not kill bacteria but slow their

growth and reproduction rate

Bacteria need

• OxygenThose that require oxygen are called Aerobic

Those that do not are called Anaerobic

Bacteria Need

• Darkness– They like the dark they become very active

and multiply rapidly

• Light is bacterias worst enemy. When exposed to sunlight, they become sluggish and die rapidly

Bacteria Need

• Dead or Living Matter– Saprophytes-bacteria that live on dead matter

or tissue

– Parasites-Bacteria that live on living matter or tissue

– http://www.youtube.com/watch?v=gEwzDydciWc

– http://www.youtube.com/watch?v=4lmwbBzClAc&feature=related

Viruses

• Smaller that bacteria.

• Cannot reproduce or grow until they have taken over a living cell.

• consists of a core of RNA or DNA, generally surrounded by a protein or lipid– Common cold, smallpox, chickenpox,

measles, mumps, flu, fever blisters. – AIDS

• viruses can remain dormant for long periods of time.

• Vaccines jump-start the human immune system by teaching it how to produce protective shields, called antibodies, to battle a specific virus.

• http://www.youtube.com/watch?v=ywIFdoMd5ok• http://www.youtube.com/watch?

v=FQWCFt9y51U• http://www.youtube.com/watch?v=A409yO-

G1Mk&NR=1

Protozoa

• Larger that a virus but also grow within a Host cell.

• Cause trichomoniasis, amebic dysentery, malaria

Fungi• Very low forms of plant life.

– Molds– Yeasts

• Can cause – Athletes foot– Thrush– Vaginitis– Lung disease– Jock Itch

• Candida can be found in soil, inanimate objects, food, and hospital environments

• This causes the fungus found in the mouth and vagina.

• Tinea corporis

• Causes ringworm of beard, scalp, and body. Also causes Jock Itch and Athletes foot.

Rickettsiae

• Parasites that live in lice, fleas, ticks and mites. • When one of these carries is infected with

rickettsiae and bites a person the disease is transferred to that person.

• Responsible for worlds worst epidemics: – Typhus – Spotted fever

• Rodent and Insect Control help prevent spread

How Microorganisms affect the body

• Some produce Toxins that affect the body.– Enterotoxin produced by staphylococcus is

the cause of food poisoning– Tetanus bacilli produces a toxin that enters

the blood stream causing nerve damage and death.

• Some invade cells and destroy them “cell invasion”

• Some cause allergic reaction– Runny nose, watery eyes, and sneezing

How Microorganisms Spread

• Must have susceptible host– Low immune system

• Caused by poor diet, fatigue, stress or poor health

• 5 primary ways they spread– Direct contact-person to person– Indirect contact-object to person– Airborne-carried in air– Oral Route-carried in water or food– Insects and pests-carried by insects

Prevention of Microorganisms

• Asepsis-free from germs– Employees being clean and neat– Proper handling of equipment– Sterile procedure– Using proper solutions

• Bacteriostatic=slow or stop bacteria growth– Use on skin

• bacteriocidal=kill bacteria– Use on equipment

– Washing hands– Follow Standard Precaution

Standard Precaution• Create in 1985…to prevent HBV and HIV

• ALL BLOOD AND FLUIDS ARE TREATED AS IF THEY ARE INFECTED

• OSHA mandated that all employees that might come in contact with body fluids must be offered immunizations and training within 10 days of hire.

http://www.youtube.com/watch?v=JHRu8eSUHU8&feature=related

Standard Precaution Guidelines

• Gloves

• Gowns or aprons

• Mask and eyewear

• Special mask that seal against the face

• Handwashing

• Clean all equipment

Transmission Based Precautions

• Used when patient is suspected to have:– Airborne– Droplet – Contact Precations

Airborne

• Standard Precaution

• Private Room with specific ventilation

• Keep door closed

• Wear respiratory protection

• Wash hands– Before entering– Before leaving – After leaving

Droplet

• SP

• Private Room or Room with pt. with same microorganism

• Wear mask w/in 3 ft.

• Wash hands– Before entering– Before leaving – After leaving

Contact

• SP

• Private Rm or Room with pt. w/ same microorganism

• Gloves/gown w/ contact with pt. or contaminated surfaces

• Wash handsWash hands – Before entering– Before/after leaving