Flashcards in Chapter 11 Deck (197)
Microorganisms that are normally present in and on the
body are called ____>
Biological survival advantage to the
microbe to live in a host
that can provide both nutrients and _____.
The host benefits as _____ can help to exclude
Some microbiota can even improve _______ to the host.
i.e. E. coli in the intestines can produce vitamin K
______ we have a peaceful coexistence with out microbiota.
Out microbiota outnumber our human cells ____ or there are ___ more bacterial cells than human cells.
Sites with Microbiota
Skin and its adjacent mucous membranes
gi tract (various parts)
outer opening of urethra
external ear canal
external eye (lids, conjunctiva)
Most areas of the body in contact with the outside environment harbor _____.
Sites that have no contact with the external environment (directly or indirectly) should be _____ - internal tissues adn organs along with their fluids (CSF, blood, muscles, etc. )do not harbor normal microbiota.
Each site of _______ has a relatively constant
population, although it can alter a bit over time and as we
_____ are typically passing through
_____ are normal microbiota that can sometimes cause opportunistic infections.
Opportunistic microbes can occur in hosts with ____ or suppressed immune systems.
weakened host defenses
Opportunistic microbes can occur when host defenses are ____ such as during surgery.
_____ during embryonic
Passing through the birth canal exposes the baby to the
vaginal ____. This begins the colonization
C-section babies are exposed via adult
they are held
Microbiota colonization ______ as the baby interacts
with the environment and even breathes.
Within ____ hours after delivery, a vaginally
baby has been colonized by
8 - 12 hours
______ babies start with a mixed population of coliforms, Lactobacilli, Strep & Staph
_____ babies tend to start with Bifidobacterium whose growth is favored by a growth factor in breast milk. The organisms colonies milk duct and passes to baby.
________ continues as the infant comes into contact with family members, health care personnel, the environment.
By the time babies ____ or ____ anything other than formula or breast milk, their normal microbiota is about the same.
eat or drink
______ have the potential to cause disease in every individual (healthy and immunocompromised)
_____ cause disease in immunocompromised hosts and not typically healthy individuals (unless their immune systems are breached or they are temporarily immunocompromised)
_____ is a microbe that can cause disease is a susceptible individual.
_______ is an organism's potential to cause infection or disease. The more pathogenic an organism, the more severe its disease process is.
______ is any characteristic or structure of the microbe that contributes to its virulence
The majority of pathogens are adapted to a specific portal of _____.
For many pathogens, if they enter the ____ portal, they will not be infectious.
i.e. influenza causes disease via entrance tot eh nasal mucosa but will not cause a skin infection
Occasionally, ______ portal can be used for entry.
more than one
i.e. Mycobacterium tuberculosis can enter through both the respiratory and gastrointestinal tracts to cause disease
The _____ is a portal of entry via nicks, abrasions, punctures, mucous membranes of the lips, burrow through the skin, via insect bites, and conjunctiva of the eye.
i.e. Staph bolis
Herpes simplex 1
The _____ is a portal of entry by eating/drinking contaminated foods and fluids via fomites.
The ____ is a portal of entry via inhalation of offending organism.
The ______ is a portal of entery through the skin/mucosa of penis, external genitalia, vagina/cervix, urethra; may enter through an unbroken surface or through a cut or abrasion.
Some microbes can cross the ____ and harm the fetus.
i.e. Treponema causing Syphilis
Other infections occur perinatally, when the child is contaminated by pathogen in the _____.
_____ infections is an acronym for a group of diseases that cause congenital (present at birth) infections.
What does TORCH stand for?
Toxoplasmosis, "other", rubella, cytomegalovirus, and herpes simples
_____ is the minimum number of microbe needed to cause disease (for an average individual)
infectious dose (ID)
ID50 is the number of microbes needed to cause infection in ___ of a population.
For most individuals, infection only proceeds if the proper infectious ____ is present.
Microorganisms with smaller IDs have greater ______. Only a few microbes needed to cause disease.
ID for tuberculosis about ___ cells.
ID for gonorrhea is ____ cells.
ID for cholera is _____ cells
Adhesion to the host is dependent on binding between specific molecules on both the host and _____. Often this is proteins on the surface of the pathogen binding to host cell receptors.
A pathogen is limited to only those cells (and organisms) to which it can successfully bind. Colonization depends on ____.
Firm attachment is almost always a prerequisite for causing ____ since the body has so many mechanisms for flushing microbes from tissues.
Occasionally microbes can cause disease via toxins without ____.
An example of an adhesion is ______ fimbriae attach to genital epithelium.
An example of adhesion is Strep pyogenes adheres via its _____.
An example of adhesion is Influenza binds via its spikes binding to ______.
host cell receptors
An example of adhesion is when parasitic worms use suckers, hooks, and ____ to attach to host tissues.
______ are white blood cells that engulf and destroy foreign materials and pathogens. These are part of your immune system. (3rd step - surviving host defenses)
______ are secreted by some pathogens to avoid pahgocyte attack. (3rd step - surviving host defenses)
An example of surviving host defenses is when ____ are toxic to white blood cells. Produced by Streptococcus and Stp\aphylococcus species.
______ makes it difficult for the phagocyte to engulf the pathogen, for example Neisseria species.
Capsule (3rd step - surviving host defenses)
Some pathogens can _____ after ingestion (bypassing their killing mechanisms).
survive inside phagocytes
(3rd step - surviving host defenses)
Three main ways that microorganisms cause damage to their hosts.
1.directly through the action of enzymes which damage host cells and tissues
2.directly through the action of toxins which cause damage to host cells and tissues
3. indirectly by inducing the host’s defenses to
respond excessively or
inappropriately, resulting in the host’s immune system causing damage or even shock and
Extracellular enzymes, ____, are secreted enzymes that break down and damage tissues or dissolve the host's defense barriers.
_____ degrade mucus making it easier for pathogens to access mucus lined tissues.
_____ degrade keratin making it easier for pathogens to colonize and remain in keratin rich tissues (like skin)
_____ degrade collagen. Collagen found in connective tissues in the body.
_____ degrade hyaluronic acid. Hyaluronic acid found between cells in the body.
_____ are a potent source of cellular damage.
____ is a specific chemical product that is poisonous to other organsisms.
Toxins are named according to their ___.
____ act on the nervous system.
____ act on the intestines.
_____ lyse red blood cells
____ damage the kidneys
Characteristics of bacterial toxins
effects on teh body
manner of release
_______ are proteins secreted by some bacterial species. Exotoxins have a strong specificity for a target cell and extremely powerful, sometimes deadly effects.
_____ are lipopolysaccharide (LPS), part of the outer membrane of the gram-negative cell walls
Exotoxins toxicity is toxic in ____.
Exotoxins effects on the body are specific to a ____.
cell type (liver, blood nerve)
Exotoxins chemical composition is made of ____.
Exotoxins immune response ____.
Exotoxins _____stimulate fever
Exotoxins manners of release is ____.
secretion from a live cell
Exotoxins typical sources are _____.
a few gram positive and gram negative
_____ is a bacterial species that can produce endospores and a potent exotoxin.
Disease occurs most often when wounds become _______ with C. tetani endospores from the environment.
Once in the host, a nice warm environment, the endospores germinate (bacterial cells grow) and the growing cells begin to ____ that migrates through the host body.
Endotoxin toxicity occurs in ____.
Endotoxin effects the body via ______.
system: fever, inflammation
Endotoxin chemical composition is a ____.
lipopolysaccharie of cell wall
Endoxtoxin immune response ___ stimulate antitoxins.
Endotoxins maner of release is by the ____.
cell via shedding or during lysis
Endotoxins typical sources are ____.
gram negative bacteri
____ disease progression begins with the toxin migration along neural paths from the wound to site to the CNS. Once at teh CNS, the toxin affects the _______. Disease results in progressive rigidity and violent spasms of the torso and limb muscles. Pharyngeal muscles affected and death typically results in respiratory failure.
C. botulinum produces ____, one of the most lethal toxins known.
C. botulinum is commonly found in ___ in the form of endospores.
When the endospores find a hospitable environment they will germinate into growing cells and begin producing endotoxin with ______.
with C. botulinum happens occasionally happens in the canning process with ____ cans that indicate that something is growing inside producing gases which expand the can.
puffed out cans
____ disease is most often an intoxication and not a bacterial infection. In these cases people ingest the toxin which alone can cause disease without the ingestion or colonization of bacterial cells.
When ____ botulism can happen when a baby ingest C. botulinum that colonizes and produces toxin inside the body.
Infant botulism can happen from ___ contaminated with soil containing endospores. This is why babies under ___ should not be given honey.
under 1 years old
Botulism disease process begins with ingestion and the toxin is absorbed by the upper GI tract and passes into the blood stream. The exotoxin moves to the peripheral neuromuscular synapses and blocks the release of the neurotransmitter _____. This results in paralysis.
Wounds can also become contaminated with ____, resulting in a wound botulism.
Treatment for botulism, if caught early, you can use an ___ that blocks the action of neurotoxin circulating in the blood.
The mortatiity rate for untreated botulism is ___.
C. diptheriae causes ____, a toxin mediated disease.
Fatality rate for diphtheria is ____ (higher in the persons younger than 5 and older than 40)
Transmission of ____ occurs from direct respiratory or physical contact with patient or carrier.
In areas where diptheria is endemic, C. diphtheriae in as _______ nasopharyngeal flora is common.
C. diptheriae is gram _______ that does not produce endospores.
Diphtheria disease is characterized by sore throat, fever, and the formation of ______ on the tonsils, pharynx, and/or nasal cavity.
a membranous coating
The membranous coating caused by Diphtheria is thick and strong fibrous coating that can result in ____.
Diptheria toxin causes ____ of host cells and tissues.
A form of diptheria can affect the skin causing _____.
_____ are any objective evidence of disease as noted by an observer.
i.e bacteria in a blood sample
____ are subjective evidence of disease as sensed by the patient.
i.e. headach or feeling bad
______ when a disease can be identified or defined by a certain complex of signs and symptoms.
When microbes enter the body, remain confined to a specific tissue is called _____.
i.e. boils, warts,
An infection spreads to several sites and tissue fluids (usual via the bloodstream), but may travel by other means such as nerves (rabies) and cerebrospinal fluid (meningitis) is called _____.
i.e. mumps, rubella, aids, chickenpox
Infectious agent spreads from a local site and is carried to other tissues is called a ____.
i.e. tb, pharyngitis
Several agents establish themselves simultaneously at the infection site is called ___.
mixed infection or polymicrobial infection i.e. human bite infections, wound infections, gas, gangrene
The initial infection is called the ___.
i.e. can be any infection
A second infection caused by a different microbe, which complicates a primary infection; often a result of lowered host immune defenses is called a ____.
influenza, complicated by pneumonia
Infection comes on rapidly with sever but short lived effects is called a ____.
an acute infection
Infection that progresses and persists over a long period of time is called ____.
Signs of infection in the blood.
bacteremia or viremia
_____ is a sign of blood infection that increases the level of white blood cells.
____ is a sign of infection, when white blood cells decrease.
______ is a general state in which microorganisms are multiplying int he blood and are present in large numbers when there is an infection in the blood.
____ or viremia is a bacteria or viruses that are present in the blood but not multiplying.
Stage of infection
1. finding a portal of entry
2. attaching firmly
3. surviving host defenses
4. causing damage (disease)
5. exiting host
_____ is the primary habitat in the natural world from which a pathogen can be found living.
_____ include any area that is not living (not a live host). These tend to be environmental such as soil and water for examples.
____ are the host in which this organism can be found consistently including animals, insects, humans for example.
A ____ carrier is an individual who carries a pathogen without disease symptoms and is capable of spreading it to others.
Recovery of the host does not always mean the microbe has been removed or destroyed by ___.
____ is a dormant state of microbes in certain chronic infectious diseases.
_____ occurs with herpes simples, herpes zoster, hepatitis, HIV
_____ occurs with syphilis, thyphoid fever, tuberculosis.
Progression of Infection
1. incubation period
____ period is the time from initial contact with the infectious agent (at the portal of entry) to the appearance of the first symptoms. This can last from 2 to 30 days.
_____ period is when the earliest notable symptoms of most infections appear as a vague feeling of discomfort. This short period lasts 1-2 days.
_____ period occurs when the infectious agent enters, during which it multiplies at high levels, exhibits it greatest virulence, and becomes well established in its target tissues. This period if often marked by fever and other prominent and more specific signs and symptoms, which can include cause, rashes, severe pain, etc. The length of the this period is extremely variable.
As the patient begins to respond to the infection, the symptoms decline sometimes dramatically, other times slowly. During the recovery that follows, called the ______, the patient's strength and health gradually return owing to the healing nature of the immune response. During this period, many patients stop taking their antibiotics, even though there are still pathogens in their system. The bacteria that are left to repopulate are the ones with the higher resistance.
Review stages of infection and disease graph p 303
____ is a living organism that transmits an infectious agent from one host to another
The majority of vectors are biting arthropods like ____ and ____.
ticks and mosquitoes
_____ is an infection indigenous to animals but naturally transmissble to humans.
Rabies, Anthrax, and salmonella are types of ____.
Rabies is passed from mammals to ____.
Anthrax is passed from ______ to humans.
Salmonella is passed from _____, ____, reptiles, rodents to humans.
____ participates in a pathogen's life cycle in some way.
i.e. plasmodium species causing malaria need the human host and mosquito to complete a life cycle
_____ transport the infectious agent without being infected.
i.e. a fly landing on dog feces in one yard and landing on food at a picnic in another yard
_____ is when an infected host can transmit to another host and establish infection in that host.
______ does not arise through transmission of the infectious agent from host to host.
i.e. invaded by his or her own microbiota
_____ shelter a pathogen, spreads it to others without any notice, and who may not have experienced disease.
Direct transmission of communicable infectious diseases
1. contact - sex, kiss
2. droplets - cold, chickenpox
3. vertical - HIV, syphilis
4. biological vector - west nile, malaria
Indirect transmission of communicable infectious diseases
1. fomites - S. aureus
2. food, water, biological products - E. coli, salmonella
3. Air - tb
____ or ____ diseases are disease must be reported to authorities. Still other disease are reported on a voluntary basis.
reportable or notifiable diseases
Review reportable diseases pg 315
_____ deals with the incidence, distribution, and possible control of diseases. who, what, when , where...
_____ is the total number of deaths in a population due to a disease.
_____ is the total number of existing cases with respect to the entire population. This allows us to determine a person's likelihood of having a disease in that population.
Prevalence is a measure often used to determined the level of _____ in a population.
_____ measures the number of new cases over a certain time period. This allows us to determine a person's probability of being diagnosed with a disease during a given period of time.
_____ laid the foundations of modern epidemiology.
Before the discovery of the germ theory, Florence Nightingale understood that _____ contributed to disease.
Florence Nightingale instituted revolutionary methods in military field hsopitals, including ____ and towels fore each patient, cleaning of floors, and unclogging of sewage pipes.
Florence Nightingale's notes demonstrated that more men died of disease than ____ during war.
An infectious disease that exhibits a relatively steady frequency over a long time period in a particular geographic locale
When statistics indicate that the prevalence of an endemic or sporadic disease is increasing beyond what is expected for that population, the pattern is described as ______.
When occasional cases are reported at irregular intervals in random locales. i.e.e tetanus
The spread of an epidemic across continents is a ______. i.e. AIDS, influenza
Koch's postulate theory has 4 exceptions.
1. some infectious agents cannot be readily isolated or grown in the lab
2. some viruses can only infect humans
3. some disease like meningitis can be caused by many different microbes
4. some diseases are not always microbial such as lung disease or liver disease.
There are some reasons why these Koch's postulates do not work in all situations, which Koch ____ relaize in his time.
______ is the cause of infection and disease.
i.e. vibrio cholera is the etiolgoical agent of the cholera
Koch's postulate theory includes a series of steps that became the standard for determining a specific disease is caused by _____.
a specific microbe
* still an essential role in modern epidemiology
1.There should be evidence of a specific microbe in every case of disease (and only in the sick individuals/animals)
2.You should isolate the microbe from infected individual and grow in apure culture in lab
3.Taking that pure culture, inoculate a susceptible healthy host. This should result in the same disease every time.
4.You then need to re
- isolate the same microbe from these newly infected subjects
First MRSA isolates identified in ___.
_____ is resistant to methicillin and all the "-cillins" such as penicillin and ampicillin.
Methicillin-resistant Staphylococcus aureus MRSA
Hospital acquired (HA) MRSA became prevalen _____ to ____.
1968 to 1990s
The community acquired (CA) MRSA epidemic decade where the rates of HA MRSA remained stable while rates of CA-MRSA increased drastically.
First reports of healthy, young children dying of sever MRSA infections.
_____ precautions include mask and gloves, double gloving decreases risk.
____ include gowns, aprons, and body coverings during surgery or emergencies.
_____ include use of puncture-proof containers for sterilization and discard. Sharps should never be recapped to reduce accidental sticks of health workers.
_____ use germicidal soap when there is a risk of exposure.
hand washing precautions
______ include vaccinations when available and do not come to work when sick.
health care worker precautions
Top 3 most common nosocomial infections include
surgical site infection
Gram ___ intestinal biota cultured in more than half of the patients with nosocomial infections. Gram ____ bacteria an yeasts make up the rest.
Recent evidence suggests that more than ____ of nonsocomial infections could be avoided by consistent and rigorous infection control methods.
Medicaid and medicare not longer reimburses hospitals for nosocomial ____, vascular catheter-associated infections, and surgical site infections, increasing their financial motivations to avoid these HAIS.
Infection control officers & stringent protocols in place in many hospital settings to help decrease ____.
Nonsocomial infections are acquired as a result of a ____.
aka HAI or hospital acquired infections
Nosocomial infections are estimated to occur in 0.1 - 20% of all admitted patients, with an average of ____.
There are ___ cases a year of nosocomial infections, resulting in approximately 90,000 deaths annually.
2-4 million cases a year