Chapter 4 Microbiology for Sterile Processing Technicians, HSPA Manual 9thEd.

Microbiology

The study of microorganisms. The scientific study of the nature, life and action of microorganisms.

Contamination

The state of being soiled by contact with infectious organisms or other materials.

Cells

The basic units of all living organisms (plants, animals, protozoa and bacteria) and they are the smallest unit that can live, grow and reproduce.

Nucleus

The controlling unit of the cell.

Cytoplasm

The material that fills the cell.

Cell membrane

The outer membrane that allows some liquids and gases to seep in and out of the cell.

Bacterial cells

Cells that differ from both plant and animal cells because they have no membrane to separate the nucleus from the cytoplasm.

SP technicians

Sterile Processing technicians who have the responsibility to protect patients from microorganisms in the healthcare environment.

Microorganisms

Unseen organisms that can cause serious illness and even death.

Environmental conditions for bacterial growth

Conditions necessary for bacterial growth and survival.

Methods to identify microorganisms

Techniques used to identify and classify microorganisms.

Basic procedures to control microorganisms

Procedures reviewed to control microorganisms.

Beneficial microorganisms

Microorganisms that are harmless.

Dangerous microorganisms

Microorganisms that can cause harm or illness.

Transmission of microorganisms

How microorganisms are transmitted.

Control and elimination of microorganisms

Methods by which microorganisms can be controlled and eliminated.

Healthcare environment

The setting in which SP technicians work and must protect patients from microorganisms.

Risk of infection

The increased likelihood of infection in individuals with compromised immune systems or natural body defenses.

Infection examples

Colds or the flu caused by microorganisms.

Understanding of microbiology

The knowledge necessary for SP technicians to effectively perform their duties.

Microbial impact

The dramatic effect microorganisms have on the world.

Precautions against germs

Actions like washing hands before eating and after using the restroom to protect against germs.

Job duties of SP technicians

Duties that may increase the risk of exposure to harmful microorganisms.

Beneficial Bacteria

95% of bacteria are beneficial and essential; they are everywhere in nature and necessary for the existence of humans, plants and animals.

Sewage Treatment

Microorganisms are useful in sewage treatment to convert waste materials into soluble, odorless compounds for disposal.

Harmless Microorganisms

Harmless microorganisms are found on human skin and hair, in the intestinal tract, and in some bodily discharges.

Pathogens

Microorganisms that can cause illness are called pathogens.

Disease Mechanism of Pathogens

Pathogens cause disease by producing powerful toxins that interfere with how body systems work.

Healthcare-Associated Infections (HAIs)

Disease-causing organisms can reside on instruments and devices used in patient care, leading to healthcare-associated infections (HAIs).

Annual HAIs Statistics

It is estimated that each year 1.7 million patients acquire infections in healthcare facilities unrelated to their initial illness, and 98,000 patients (one in 17) die due to these HAIs.

Naming Microorganisms

The first word in a microorganism's name is the genus, and the second word is the specific name of the organism, also called the species.

Pseudomonas aeruginosa

Pseudomonas aeruginosa can cause infections in the blood, lungs (pneumonia) or other parts of the body after surgery.

Escherichia coli (E. coli)

Escherichia coli can cause diarrhea, urinary tract infections, respiratory illness, and pneumonia.

Bacteria Size

Bacteria are incredibly small, requiring a microscope that can magnify at least 900 times to view them.

Bacteria Measurement

Bacteria are measured by microns, and most bacteria are one to two microns in size.

Bacteria Identification Methods

The most common ways to identify and classify bacteria are by shape, color change, and oxygen needs (aerobic or anaerobic).

Pathogen Definition

A pathogen is capable of producing disease.

Micron Definition

A micron is 1/25,000 of an inch or 1/1,000 of a millimeter.

Aerobic Definition

Aerobic bacteria require the presence of air or free oxygen.

Anaerobic Definition

Anaerobic bacteria can live in the absence of atmospheric oxygen.

Bacterial Shape Determination

The shape of bacteria is determined by cell wall structure.

Spherical Bacteria

Spherical bacteria are shaped like a circle or sphere (coccus), examples include Staphylococcus aureus and Streptococci.

Rod Bacteria

Rod bacteria are shaped like rods or bricks (bacillus), examples include Pseudomonas aeruginosa and Enterobacteria.

Spiral Bacteria

Spiral bacteria are shaped like spirals (spirilla), an example is Helicobacter pylori.

Endospores

Certain bacteria can change into a different form called endospores by developing a thick coat around the cell's nucleus when conditions for growth are not adequate.

Infectious Spores

Some spores, such as Bacillus anthracis and Clostridium species, can become infectious and produce toxins once inside the body.

Spores

Highly resistant structures formed by microorganisms to survive adverse conditions.

Color Change

The process by which bacteria, typically clear and colorless, are dyed with a stain to view their shape.

Gram staining

A multi-step process using several stains and rinses to classify bacteria based on their ability to retain or lose the primary stain.

Gram stain

Differential stain used to classify bacteria as gram positive or gram negative.

Gram-negative bacteria

Bacteria that do not retain the purple stain after treatment with iodine and stain pink instead.

Examples of Gram-negative bacteria

Pseudomonas aeruginosa, E. coli, Salmonella species, and Klebsiella species.

Gram-positive bacteria

Bacteria that retain the purple stain even if a decolorizer is used.

Examples of Gram-positive bacteria

Staphylococcus aureus, Bacillus anthracis, and Clostridium difficile.

Acid-fast bacilli

Rod-shaped bacteria that are very difficult to stain but resist decolorization with a diluted acid-alcohol solution.

Examples of acid-fast bacilli

Mycobacteria such as M. tuberculosis and M. leprae.

Aerobic bacteria

Bacteria that require oxygen to grow.

Anaerobic bacteria

Bacteria that must have oxygen eliminated from their environment to grow.

Examples of anaerobic bacteria

C. tetani and C. botulinum.

Conditions for microbial growth

Specific requirements such as nutrition needs, temperature, moisture/humidity, pH, and light.

pH

Measure of alkalinity or acidity on a scale of 0 to 14; pH of 7 is neutral.

Pathogenic bacteria

Bacteria that thrive where their specific nutritional needs can be met.

Examples of adaptable bacteria

Staphylococci can grow in many areas of the body, while Neisseria gonorrhoeae requires specific environments.

Temperature requirements

Bacteria have varying temperature preferences for growth.

Moderate temperature bacteria

Bacteria that thrive at moderate temperatures, such as 37°C.

Warm temperature bacteria

Bacteria that prefer warmer temperatures, such as 102°F to 198°F.

Moisture and relative humidity

Play a major role in the growth and survival of microorganisms.

Binary fission

The typical method of bacterial reproduction in which a cell divides into two equal parts.

Multiple Drug-Resistant Organisms (MDROs)

Microorganisms that have become resistant to antibiotics used to treat bacterial infections.

Methicillin-resistant Staphylococcus aureus (MRSA)

A bacterium that lives on the skin and is known for causing severe infections.

Vancomycin-resistant Enterococci (VRE)

A bacterium that lives in the bowels and is transmitted when hands become contaminated from infected feces, urine, or blood.

Vancomycin-resistant Streptococcus pneumoniae

Causes pneumonia in susceptible humans and is transmitted through direct contact with infected droplets.

Klebsiella

A bacterium that causes pneumonia, nasal infections, urinary tract infections (UTI), wound, and bloodstream infections.

Acinetobacter

A bacterium normally found in soil that can cause various illnesses ranging from pneumonia to serious blood or wound infections.

Carbapenem-resistant Enterobacteriaceae (CRE)

A family of germs that are difficult to treat due to high levels of antibiotic resistance.

Optimal pH range for pathogenic microorganisms

7 to 7.8, the same pH as blood.

Dark conditions

Favorable to the growth of bacteria.

Sunlight

Lethal to many organisms in their actively growing or vegetative stage.

Resting stage of spores

The stage in which spores of gram-positive bacilli are most resistant to sunlight.

Droplet route

A primary method of bacteria transmission.

Contaminated water or food

A primary method of bacteria transmission.

Direct contact through wounds

A primary method of bacteria transmission.

Disease-carrying animals

A primary method of bacteria transmission.

Infected fluids

Can transmit infections, especially in the case of Strep infections.

Infected surfaces

Can transmit infections, especially in the case of VRE and MRSA.

Symptoms of Acinetobacter infections

Vary depending on the disease caused by the bacterium.

Transmission of Klebsiella

Typically transferred through hand contact.

Transmission of Pseudomonas

Through hand-to-hand contact or contact with contaminated surfaces.

CRE infections

Infections associated with devices such as flexible endoscopes and ventilators, contributing to death in up to 50% of infected patients.

Viruses

The smallest microorganisms, about 1,000 times smaller than bacteria, that enter living cells to reproduce and usually destroy the cell.

Transmission of viruses

Viruses are transmitted primarily by the airborne or droplet route.

Bloodborne viral pathogens

Significant pathogens in healthcare include human immunodeficiency virus (HIV), hepatitis B virus (HBV), and hepatitis C virus (HCV).

Ebola virus

A viral disease caused by the filovirus species, contracted through contact with blood or body fluids of an infected animal or human.

Incubation period for Ebola

Ranges from two to 21 days after exposure.

Acute viral gastroenteritis viruses

Viruses transmitted by contaminated water or food, including rotavirus, Norovirus, and noro-like virus.

Transmission routes for hepatitis A

Contracted by unwashed hands or eating raw or improperly cooked food.

Viruses spread by direct contact

Include cold sores (herpes labialis), genital herpes, genital warts, infectious mononucleosis, and rabies.

COVID-19 transmission

Can be transmitted through direct contact, indirect contact, airborne, and droplet routes.

Survival of viruses outside host

Some viruses can survive away from the host for many hours or days in organic material.

Herpes simplex virus (HSV) survival

Can survive in a dry state for 1½ to four hours on toilet seats, up to 72 hours on cotton gauze, and 18 hours on plastic.