Surg 101--Chapter 7 Flashcards
What is microbiology?
The study of microscopic animals and plants.
In the OR, we are particularly concerned with preventing infections caused by bacteria and viruses transmitted by _____.
instruments, equipment, and personnel
What is medical microbiology?
The study of infectious diseases caused by microorganisms.
What is pathology?
The study of disease mechanisms, diagnosis, and treatment.
What is the Linnean system?
One of the earliest classification systems developed to identify and study living things.
Who developed the Linnean system?
Carol Linnaeus
How many categories are used to classify organisms.
Seven
What are the classification categories used in biology?
- Genus
- Family
- Order
- Class
- Phylum
- Kingdom
- Domain
Damn, Kevin’s Poor Crew Only Feels Good
What are the 6 important microbes in human disease?
- Bacteria
- Viruses
- Prions
- Fungi
- Protozoa
- Rickettsia
Rich People Probably Feel Very Bad
When was cell theory developed?
In the 1600’s, shortly before the development of the light microscope.
Developed the light microscope and observed “little animals” under magnification.
Anton Von Leeuwenhoek
Developed the first smallpox vaccination.
Edward Jenner
Discovered the association between hand washing and a decrease in puerperal infection.
Ignaz Semmelweis
Disproved the theory of spontaneous generation and developed germ theory of infection.
Louis Pasteur
First practiced surgery using antiseptic practices.
Joseph Lister
Offered the first proof of the germ theory using Bacillus anthracis.
Robert Koch
Developed the acid-fast stain.
Paul Ehrlich
Developed the gram stain.
Christian Gram
Developed the first rabies vaccine.
Louis Pastuer
Discovered the virus.
Dimitri Iosifovich Ivanovski
Proved that Mosquitos carry yellow fever.
Walter Reed
Discovered a cure for Syphilis.
Paul Ehrlich
Discovered penicillin.
Alexander Fleming
What is cell theory?
- The cell is the fundamental unit of all living things.
- All living things are composed of cells.
- All cells are derived from other cells.
What forms the basis of modern biology?
Cell theory
What is the basic unit of a living organism?
The cell
What two types are cellular organisms divided into?
Prokaryotes and eukaryotes
The basic type of cell.
Eukaryotes
The inside of the cell contains _____?
Cytoplasm
The largest organelle.
Nucleus
What is surrounded by a membrane and contains the cell’s DNA, which enables the cell to replicate.
Nucleus
The DNA is contained within the cell’s _____.
Chromatin
What is a protein substance that contains the genetic code for the cell?
Chromatin
What is the endoplasmic reticulum?
Facilitates the movement of protein out of the nucleus.
What is the nucleolis?
Located inside the nucleus, has proteins and RNA necessary for cell reproduction.
What is the Golgi apparatus?
Extension of the endomembrane, composed of layered sacs which store and modify large molecules and transport them inside the cell.
What are mitochondria?
Responsible mainly for synthesizing ATP to provide energy for the cell.
A group of single-celled microbes, includes only bacteria and Archea.
Prokaryotes
Prokaryote that causes disease.
Bacteria
What is the primary structural difference between a prokaryote and a eukaryote?
The absence of a distinct nucleus in the prokaryote.
What is the only true organelle of the prokaryote?
Ribosome
What do ribosomes do?
Synthesize protein
What is osmosis?
The movement of liquid through a semipermeable membrane according to differences in the concentration of substances on either side.
A process in which the cell engulfs large particles from outside the cell.
Endocytosis
Process in which the cell takes in water and small particles by surrounding them with a membrane-covered blister or vesicles.
Pinocytosis
Process in which large particles (such as microbes) are engulfed and digested by the cell.
Phagocytosis
During _____ the particle is surrounded by a membrane that fuses with another cell organelle called the _____.
Phagocytosis
Lysosome
The contents of the Lysosome are released from the cell through _____.
Exocytosis
Certain microbes cause disease when conditions are favorable for them. When conditions are favorable to the host, disease is more likely to be resisted. These variable conditions include:
- The number of microbes in the body (the dose)
- The physiological environment in the body
- The location of entry into the body (the portal of entry)
- The strength of the body’s immune system, which determines the body’s ability to recognize and destroy harmful organisms
- The disease-producing potential of the bacteria
- The number of pathogenic microorganisms that penetrate the body
- The pathogen’s ability to adhere to the target tissue and secrete enzymes that destroy the target cells
- The pathogen’s ability to evade the body’s defense system by chemical or physical means or by mutation
What is symbiosis?
Two different species live together.
What is commensalism?
Neither organism is harmed.
One organism uses another to meet its physiological needs but causes no harm to the host?
What is mutualism?
The association benefits both organisms.
Both organisms benefit from the relationship.
What is parasitism?
One organism is harmed and the other benefits.
For identification of a particular microbe, a minimum number of colonies or individual microbes often is required to have a representative sample for study.
Bacterial culturing
Bacteria are routinely tested for their sensitivity to antimicrobials. This is done by inoculating a culture plate with the microbe and placing small paper discs impregnated with various antibacterial agents on the sample.
Culture and sensitivity
A procedure used to prepare a microbial specimen for examination under a microscope.
Staining
Staining takes place after the microbe has been _____.
applied to the slide
Routinely performed to differentiate bacteria into two primary classifications.
Gram staining
The bacterial cell wall contains a layer of _____ and _____.
sugars and amino acids
In some bacteria, the cell wall is very _____, whereas in others it is _____.
thin
thick
Gram staining reveals the thicker wall, and these bacteria are said to be _____.
gram positive
The bacteria with the thinner wall do not absorb the stain and are categorized as _____.
gram negative
What two dyes are used in gram staining?
Crystal violet and safranin
Under the microscope, gram-positive bacteria appear _____, and gram-negative bacteria are _____.
dark purple
pink
The acid-fast staining technique is used primarily for identification of _____.
Mycobacteria organisms, especially Mycobacterium tuberculosis.
What is a common acid-fast staining technique?
Ziehl-Neelsen test
This test uses the stain carbofuschin or methylene blue, which colors the cell wall pink, leaving a blue background.
Ziehl-Neelsen test
True or False: identification of the shape of bacteria is insufficient to establish the exact species.
True
What are the two main types of microscopes?
Optical microscope and scanning microscope
Which microscope uses a series of lenses to focus light on the object being viewed and an example is the electron microscope.
Optical microscope
Which microscope uses a physical probe that tracks the contours and surfaces of the object and creates an image based on the findings?
Scanning microscope
Part of the microscope that connects the eyepiece to the objective lense.
Tube
Part of the microscope that connects the viewing tube to the base and balances the microscope. Also used for carrying the microscope.
Arm
The set of lenses located at the bottom of the tube.
Objective lens
Common magnification levels of the objective lenses.
10x, 40x, and 100x
What is the normal magnification of the eyepiece?
10x
Provides fine and coarse focus by moving the serial lenses vertically.
Focus adjustment knobs
A vertical adjustment that prevents direct contact between the objective lens and the specimen.
Rack stop
A round fitting for the objective lenses. Revolves to place one of the objective lenses directly over the subject being viewed.
Nosepiece
The flat area just under the objective lenses where the specimen slide is placed. Can be moved with knobs.
Stage
Provides intense, evenly distributed light to view the specimen.
Illuminator (light source)
Located under the stage and contains two sets of lenses that focus light on the subject.
Condenser
Bacteria that cause infection are called _____.
pyogenic
Pyogenic bacteria include:
- streptococcal
- staphylococcal
- meningococcal
- pneumococcal
- gonococcal
- coliform bacilli
Represents the largest variety of infectious microorganisms and cause the greatest number of post-op infections and other HAI’s.
Bacteria
Rod-shaped bacteria
bacilli
Curved or spiral-shaped bacteria
spirochetes
Spherical bacteria
cocci
Bacteria that require oxygen to live and grow
strict aerobes
Bacteria that cannot live in the presence of oxygen
strict anaerobes
Anaerobes are important in the process of infection, because they can _____.
proliferate in deep traumatic or surgical wounds
Can live with or without axygen
facultative bacteria
What is normal blood pH?
7.35 - 7.45
What is desiccation?
Destroying bacteria by drying them
How do bacterial cells reproduce?
asexual fission
What is a vegetative reproduction form that some bacteria are capable of producing?
endospore
What are the four phases of bacterial growth?
- Lag phase
- Log (Exponential) phase
- Stationary phase
- Death phase
Phase in which bacteria do not divide, but are preparing for cell division.
Lag phase
Phase of active and rapid cell division
Log (exponential) phase
Phase in which bacteria have used up available nutrition; cell division stops.
Stationary phase
Phase in which bacteria can no longer survive and the colony dies out.
Death phase
Chemicals contained within the bacterial cell wall.
Endotoxins
Proteins produced as a result of bacterial metabolism.
Exotoxin
Responsible for about 1/3 of all bacterial infections in human beings.
Gram-positive cocci
Gram-positive cocci:
- Staphylococcus aureus
- Staphylococcus epidermis
- Streptococcus pyogenes
- Streptococcus pneumoniae
Staphylococcus aureus
- Most widespread cause of SSI
- 30%-70% of people are skin carriers
- Also causes endocarditis and osteomyelitis
Staphylococcus epidermis
-Usually spread by catheters, prosthetic valves, and orthopedic implants
Streptococcus pyogenes
- Causes many HAI’s
- Burn patients are particularly vulnerable
- SSI is most commonly caused by direct transmission from a contaminated surface
Streptococcus pneumoniae
- Primary cause of pneumonia and otitis media
- Spread mainly through respiratory tract
Gram-negative rods and cocci (aerobic):
- Pseudomonas aeruginosa
- Neisseria gonorrhoeae
- Neisseria meningitidis
- Bordetella pertussis
- Enteric bacteria
- Escherichia coli (E coli)
- Salmonella enterica
- Salmonella typhi
Pseudomonas aeruginosa
Found in the normal gastrointestinal tract
Neisseria gonorrhoeae
STD
Neisseria meningitidis
Bacterial meningitis is a highly contagious infection of the meninges which covers the brain and spinal cord
Bordetella pertussis
Causes whooping cough
Enteric bacteria
Gram-negative rods, facultative anaerobes
Escherichia coli (E coli)
Resident bacteria of the gastrointestinal tract
Salmonella enterica
Common cause of food poisoning
Salmonella typhi
Causes typhoid
Spore-forming bacteria:
- Clostridium perfringens
- Clostridium tetani
- Clostridium difficile
Clostridium perfringens
Anaerobic bacteria that causes rapid tissue death in deep wounds deprived of oxygen
Clostridium tetani
Causative bacteria of tetanus
Clostridium difficile
Spore-forming bacterium that cause severe diarrhea
Nonliving infectious agent that ranges in size from 10 to 300 nm.
a virus
A complete virus particle is called a _____.
virion
Classified by a number of complex systems and categories, such as by morphology, chemical composition, and method of replication.
viruses
Consists of a double or single strand of either DNA or RNA.
virion
The genetic material of a virion is surrounded by a protein coating called a _____.
capsid
The cycle of replication and lysis of the host cell is called _____.
lysogenesis
A virus that invades bacterial cells is called a _____.
bacteriophage
Mechanisms that create and sustain viral disease is certain stains include:
- The ability to enter a healthy cell
- The ability to develop
- The ability to resist the host’s defense mechanisms
- Cell transformation
- The ability to synthesize substances not normally produced by the host cell
- The ability to initiate structural changes in the host cell
What are the primary modes of transmission of the HIV virus in the general public?
Sexual contact and use of contaminated needles
Occupation risk of HIV to health care workers is highest in _____.
needlestick and other sharps injuries
A disease of the liver that is caused by one of five significant viruses.
Viral hepatitis
Hepatitis that are blood-borne pathogens:
B, C, D
Hepatitis that are transmitted through contaminated food or water:
A, E
Hepatitis that is rarely fatal, and one infection results in permanent immunity to the disease
A
Hepatitis that causes chronic hepatitis, cirrhosis, massive liver necrosis, and death.
B
Hepatitis B is _____ times more infective than HIV.
100
Hepatitis that is transmitted by blood transfusions and blood products.
C
Hepatitis that is associated with HBV as a coinfection.
D
Hepatitis that causes serious acute liver disease and is transmitted by contaminated water.
E
Potentially cancer producing virus that occurs in about 15% of the population.
HPV
How many different types of HPV exist?
Approx. 40
Infection that is likely to develop into cervical cancer in women and noninvasive penile and anal cancer in men.
Chronic HPV
What is one of the best methods of preventing cervical cancer in women?
PAP test
A proteinaceous infectious particle, unique pathogenic substance, an is a protein particle that contains no nucleic acid.
Prion
Resistant to all forms of disinfection and sterilization normally used in the medical setting.
prion
Cannot be cultured in a lab, and the immune system does not react to them.
prion
What is the most important prion that affects human?
Creutzfeldt-Jakob disease (CJD)
A rare transmissible disease of the nervous system that is progressive and always fatal.
Creutzfeldt-Jakob disease (CJD)
More that _____ species of fungi exist, but only _____ are pathogenic.
70,000
300
Fungi are eukaryotes and are divided into what two groups?
molds and yeasts
Yeast are _____.
unicellular
Molds are _____.
multicellular
What is the most significant protozoal disease disease of the CNS and a major killer of children in Africa and Asia.
malaria
Not every contact with a pathogen results in infection. Certain conditions must be in effect for this to happen. What are they?
- The microbe must have an entry and and exit site
- Microbes must be present in sufficient numbers
- The environment must be well suited to the pathogen
- The host must be unable to overcome the harmful mechanisms of the pathogen
Microorganisms are transferred from a host through _____ or an _____.
direct contact
intermediate source
Nonliving source of infection.
fomite
Living source of infection
vector
Completely free of all microorganisms
sterile
Common fomites in the hospital…
- instruments
- medical devices
- bed linens
- wound dressings
- contaminated urinary catheters
Airborne transmission also occurs via _____.
droplet nuclei
A pathogen is ingested in food or through fecal-oral transmission.
oral transmission
In the health care setting, _____ is very important to the prevention of oral disease transmission.
handwashing
Almost always results from an outside source, usually the urethral orifice.
urogenital infection
Most common cause of urinary tract infection in women.
E. coli
Can result in local, regional, or systemic infection.
Skin penetration
Spread when the mucous membrane of an infected person comes in contact with the mucous membrane of an uninfected person, usually during sex.
STD
The treatment of a patient with drugs to eradicate or minimize the effects of disease caused by microorganisms is called _____.
antimicrobial therapy
Used to treat bacterial and fungal infections.
antibiotics
Antibiotics are classified according to the way they _____.
destroy bacteria
The main mechanisms of antibacterial agents are:
- Inhibition of cell wall synthesis
- Interference with genetic replication
- Inhibition of metabolic pathways in the microbe
The spread of am HAI from one person to another is called _____.
cross-contamination
Introduction of an infection into a part of the body from another part of the body is called _____.
self-infection or autoinfection
The most common HAI
UTI (usually in catheterized patients)
Second most frequent HAI
SSI
About _____ to _____ of SSI are confined to the incision, and the remaining spread to distant or adjacent sites.
60% to 70%
Splitting apart of deep and superficial wound edges.
Wound dehiscence
Protrusion of visceral contents outside the body through the ruptured incision
evisceration
Surgical wounds are classified according to the risk of _____ and _____ at the time of the surgery
contamination and infection
An accumulation of pus, drainage dead cells, and serum
suppurative
As suture materials degrade in the presence of bacteria, the wound may split open, a condition known as _____.
dehiscence
If the symptoms do not resolve, the wound may be incised again and pus and necrotic, devitalized tissue removed in a procedure called _____
incision and draining (I & D)
VRSA first diagnosed
1997
The body’s ability to accept substances that are part of the body (self) and eliminate those that are not (nonself)
immunity
Two general types of immunity
innate immunity
acquired immunity
Also called nonspecific immunity, exists from the time of birth
innate immunity
Conferred through exposure to a specific substance or microbe called an antigen.
acquired immunity
Specific proteins that trigger the immune system to launch its defenses.
antibodies
The body’s innate immune response to injury.
inflammatory response
Four classic signs of infection:
- Heat
- Redness
- Swelling
- Pain
