Transcript microbiology

THE STUDY OF MICROORGANISMS. THE
SCIENCE WHICH TREATS THE NATURE,
LIFE AND ACTION OF MICROORGANISMS
It is impossible to see
microorganisms without a
microscope…….
 Surgical Technologists must learn to see
microorganisms with their “minds eye”.
Microorganisms can pose a threat to both patients and
employees.
CONTAMINATION
 The state of being soiled or infected by contact with
infectious organisms or other material.
To effectively control
Microorganisms, Surgical
Technicians must understand:
 Basic facts about microorganisms
 How microorganisms are identified and classified
 How they grow
To effectively control
Microorganisms, Surgical
Technicians must understand:
 What conditions they need to grow and reproduce
 How they are transmitted from person-to-person and
place-to-place
 How they can be controlled and killed
Basic Facts About Microorganisms
Not all microorganisms are harmful……..
•Microorganisms are necessary for our existence
•Microorganisms help with:
1. Food development
2. Decay of leaves and other natural waste
3. Sewage treatment, and more…..
Size and structure of bacteria
 Most bacterial cells are 1-2 microns in size
 A micron is
1/25,000 of an
inch
SPORE
A microorganism capable of forming a thick wall
around itself that enables it to survive in adverse
conditions; a resistant form of bacteria.
* Bacterial spores pose specific challenges to the
Operating Room environment
Cells and more cells….
 Cells are basic units of all living organisms (plants,
animals, and bacteria)
 They are the smallest unit that can live, grow and
reproduce.
 They have different sizes and shapes
Identification and Classification of
Microorganisms:
 Common ways to identify and Classify
Microorganisms include:
1. Shape
2. Color Change
3. Need for oxygen
Classification by shape
 Bacteria are divided into 3 main groups by shape:
1. Cocci are round or spherical shaped and
occur in pairs, clusters, or chains
2. Rods (bacilli) may be large and brickshaped or small and stick-like
3. Spirals vary from comma-shaped to longer
bacteria with many twists
Bacteria are classified by color
change
 Bacteria are normally clear, color change occurs when
bacteria are subjected to certain tests.
Common stain tests
-gram stain
-Ziehl-Neilson Stain
Gram Stain Procedure:
 The gram stain is the most commonly used
differential stain for determining cell morphology.
Differential stains allow for distinguishing certain
characteristics of cells, and the stains commonly use
two or more stains. The Gram stain, which divides
most clinically significant bacteria into two main
groups, is the first step in bacterial identification
Bacteria are Classified by their
Need for Oxygen:
 Aerobic Bacteria- Capable of growing in the presence
of free oxygen. Requires oxygen
 Anaerobic Bacteria- Capable of growing in the absence
of free oxygen. Does not require oxygen
How Bacteria Live and Grow…
BACTERIA
_______________________________________
NEED THE RIGHT CONDITIONS TO GROW
Temperature Requirements for
Bacteria
 Psychrophiles – like cold temps
 Mesophiles -
like moderate temps
 Thermophiles – like warm temps
*Mesophiles are often pathogenic to humans and grow
well at body temperature.
Bacterial Reproduction
 Bacteria reproduce by dividing
 This occurs approximately every 20 minutes
 This process is call Binary Fission
Resistant Microorganisms
____________________________
 Some microorganisms adapt and change to
increase their chances of survival…..
aureus (MRSA)
____________________________
___
 Staphyloccus aureus bacteria that have developed a
resistance to Methicillin, the drug of choice
 MRSA usually occurs in patients who have been on
antibiotics therapy for a long time
(VRE)
____________________________
_
 Enterococcus bacteria that are no longer sensitive to
vancomycin
 Transmission can occur by direct contact, or indirectly
via the hands of personnel
NON-BACTERIAL ORGANISMS
“I am a real fungi , just ask
My “Shrooms”
VIRUSES PROTOZOA &
FUNGI
VIRUS
_____________________________________
ONE OF A GROUP OF MINUTE INFECTIOUS
AGENTS THAT ONLY GROW IN LIVING TISSUE OR
CELLS.
Viruses
are Tiny……
 Viruses are about 1000 times smaller than bacteria
If you were to enlarge a virus to the
Size of a baseball, the average bacterium
would be the size of the pitchers mound, and one single cell
from the human body would be the size of the entire ballpark.
Common Viral Diseases













Small pox
Rabies
Yellow fever
Influenza
Measles
AIDS
Mumps
Polio
Common colds
Shingles
Cold sores
Warts
hepatitis
Hepatitis
 Five distinct viruses A, B, C, D, and E
 A is often implicated in food borne illnesses
 B, C,D, and E are transmitted in body fluids
 There are vaccines available for A&B.
Herpes Simplex
 Recurrent skin and mucous membrane infections
 HSV Type I is associated with cold sores and fever
blisters
 HSV Type 2 is associated with genital infections.
Human Immunodeficiency Virus
(HIV)
 Causes AIDS
 Occurs when the virus enters the blood stream
PROTOZOAN
 _____________________________________
 Any one-celled animal-like microorganism is the sub
kingdom of protozoa
FUNGI
 Plant-like organism group that includes molds,
mushrooms, and yeasts without chlorophyll.
 They live by feeding off living or dead organisms
 Fungi are involved in the production of most kinds of
antibiotics
FUNGI
 Several species of fungi can cause respiratory
disease in humans who inhale spores through
dust, bird droppings, soil and other sources.
Superficial FUNGI
 Attack mainly epidermis, hair, nails, and mucosal
surfaces
 For example:
Ringworm and Athlete’s Foot
Transmission of Microorganisms
 Microorganisms cannot move by themselves, but they
have been called the “World’s Greatest Hitchhikers”
 Microorganisms can be transmitted by air currents,
dust particles, in liquids, on solid objects like
instruments and equipment….and by humans (us)
Facts about Microorganisms
 We come in contact with thousands of types of
microorganisms each day.
 Only about 1% are harmful to humans
 However, any microorganism can be harmful to
patients whose defenses are compromised due to
illness, injury or invasive procedures.
PATHOGENIC
 Disease producing
 Surgical Technologists protect patients from
pathogenic organisms
For our patients!
 The hospital is a very dangerous place!!
 Our job is to protect them
The chain of infection
Susceptible
Host
Causative
Agent
Portal of entry
Into the host
Mode of
Transmission
Reservoir
of the
agent
Portal of Exit
Of the Agent
From the
Reservoir
Causative Agent
 The microorganism that causes an infectious disease
 Characteristics that make microorganisms capable of
causing disease:
Invasiveness
Pathogenicity
Virulence
Infectious Dose
Viability in a free state
Break the chain of infection by:
 Eliminating the Causative agent
 Avoid cross-contamination
 Thorough cleaning
 Disinfection
 Sterilization
Reservoir of the agent
 The place where an infectious agent can survive
Breaking the Chain of infection:
 Reducing Reservoirs
 Surgical Technologists can reduce reservoirs by
practicing good personal hygiene and health habits
 Properly cleaning, disinfecting, and sterilizing
equipment, instruments, and utensils
 SURGICAL CONSCIENCE!!
Portal of Exit
 The path by which an infectious agent leaves the
reservoir
Portals of Exit
 Respiratory tract- sneezing and coughing
 Genitourinary Tract- Through urine, vaginal




secretions, and semen
Gastrointestinal Tract-Through vomit and stools
Skin/mucous Membrane- Through mucous or wound
drainage
Blood-Through blood transfusions or contact with
blood
Transplacental-Through the placenta from mother to
baby
Break the chain of infection by
 Protecting yourself and other from exposure
 Surgical Technologists should:
1. Practice proper waste disposal
2. Wear PPE when they may come in contact with in
infectious substances
Modes of Transmission
 Airborne- infectious agents found in tiny droplet
nuclei or dust that are suspended in the air and may
travel.
 For example:
Vector-borne- carried by insects
(rare in U.S. hospitals)
Break the Chain of Infection by:
 Maintain good hand hygiene
 Following good work practices for cleaning,
decontamination, disinfection and sterilization
 Following airflow control guidelines
 Following Standard Precautions guidelines
Portal of Entry
 The path used by an infectious agent to enter a
susceptible host
Portals of Entry
 Respiratory Tract
 Genitourinary Tract
 Gastrointestinal Tract
 Skin/Mucous Membranes
 Transplacental
 Parenteral (definition?)
Break the Chain of Infection by:
 Ensuring that equipment, utensils and instruments are
properly cleaned, disinfected, and/or sterilized
 Follow standard precautions when handling
contaminated items
Susceptible Host:
 Host Susceptibility is affected by:
1. Age
2. Disease
3. Nutritional Status
4. Compromised Immune status
5. Trauma
What we can’t see CAN hurt us!!
 Millions of tiny bacteria, too small to see, inhabit our
work area!!!
Understanding Microorganisms
Helps Surgical Technologists:
 Control their transmission
 Prevent them from reproducing
 Destroy them
 Protect patients, employees and ourselves
Preparedness
 Understanding the basics about microorganisms is the
first step in being prepared to fight them!!