Epidemiology & Pathogeneis Part 2 Flashcards
What are endogenous infections ?
Nosocomial microorganism
- caused by opportunitisic microorganisms among patients own normal flora
What is exogenous infections ?
Caused by micrograniwm that enter the patient through environment
- nosocomial
What are the 4 chain of transmission in nosocomial infections ?
Hospital staff to patient
Patient to patient
Fomites to patient
Ventilation to patient
What helps control nosocomial infections? (3)
Washing hands, proper handling of contaminated material , isolation
What are emerging infections diseases?
Brand new microbe that emerges
What increases the likelihood of emerging infectious diseases? (3)
Overuse of antibiotics
Global warming
Lack of vaccination
Why does global warming increase emerging infectious disease?
It increases the survival of reservoirs and vectors
What is the easiest way to spread a new emerging disease?
Travel
What are the 4 contributing factors for emerging infectious disease?
(GR,S,A,W)
Genetic recombination
Evolution of new strains
Widespread use of antibiotics
Changes in weather
What is an example of emerging infectious disease that follows genetics recombination?
E. coli 0157
What is an example of emerging infectious disease that is an evolution of a new strain?
SARS-CoV2
What is an example of emerging infectious disease for changes in weather?
Hantavirus
What is pathogenicity? ( ability for what ?)
Is the ability of an organism to cause disease by overcoming host defense
What is virulence ?
The degree of pathogenicity
The degree of pathogenicity is the ?
Virulence of microbe
What are the 6 establishment of disease?
( E A P, E D E )
Enter the organism ( portal of entry )
Adhere to tissues
Penetrate the tissues
Evade the immune system
Damage cells to establish disease
Exit the body
Does the disease have to enter to their preferred portal of entry ?
Yes
Which step in establishment of disease does attachment occur?
Step 2. Adhere to tissues
In which step does it infect cells? In establishment of disease
Step 3. Penetrate the tissues
Do organism need to enter to establish disease?
Yes, ALWAYS!
Does each disease have its own entry?
Yes, all are different
Can there be a disease that can enter more than 1 portal of entry into the body?
Yes
What are the 3 main portals of entry?
( MM, S, PR )
Mucous membranes
Skin
Parenteral route
What are examples of mucous membranes ? (4)
Respiratory
GI
Eyes
Genutoruinary tract
What is skin for portals of entry?
Our largest organ & outermost protective layer
What is parenteral route in portals of entry?
Deposition directly under the skin into the tissues
What are examples of parenteral route in portals of entry?
Bites, punctures, burns, injections
What is preferred portal of entry?
Entry that is required for establishment of diseases
Will HIV infect us if we were to breathe it in? Why?
No; because it isn’t it’s preferred method of entry “sex”
What does ID50 mean?
Infectious dose for 50% of population indication of virulence
What does LD50 mean?
Lethal dose of a toxin in 50% of population
What is adherence?
Attachment to tissue surfaces to establish infection
Name a few important virulence factors that promote adherence? (4)
Biofilms
Fimbriae
Capsules
Receptors
What is Adhesins?
Receptors on the surface of the host that helps with attachment
Do the adhesins have to find the right receptor to help attachment?
Yes
What is biofilms?
Masses of microbes that attach
What are examples of biofilms ?
Dental plaques
Algae on rocks
If a microbe enters through the respiratory tract, where would it come out? (3)
Sneezing, coughing, talking
What are the 4 portals of exit?
Gastrointestinal Tract
Urogenital tract
Blood
Respiratory tract
If it enters in our gastrointestinal tract, where is it going to come out?
Diarrhea, vomiting
If it enters through urogenital tract, where is it going to come out?
Urine, sexual contact
If it enters through blood, where is it going to come out?
Wounds, needles, insects
If it enters through respiratory tract, where is it going to come out?
Coughing, sneezing, speaking
Do most microorganisms have to penetrate tissues to cause disease ?
Yes!!!
What are the 2 ways where bacteria cause disease?
(VF, DA)
Virulence factors
Direct actions by bacteria
What are virulence factors?
Characteristics that help microorganisms cause infection
What are the examples of virulence factors that help the bacteria cause disease? (2 and examples )
Structural : pili
Physiological ; enzymes help to evade host defenses ; toxins
What are the 4 direct actions by bacteria that cause disease?
( A, C, I, T )
Adhesins
Colonization
Invasiveness
Toxins
What is Adhesins in direct action by bacteria to cause diseases?
Proteins that help attach to host cell
What is colonization in direct actions by bacteria to cause disease? ( in what )
Growth of microorganisms on epithelial cells ( skin & mucous membranes )
What is invasivness in direct actions by bacteria that cause disease?
Degree to where a microorganis can invade and grow in host tissue
What are toxins in direct actions by bacteria to cause disease?
Any substance poisonous to other organisms
What is the most common way that bacteria causes damage ?
Toxins
What are the 3 bacterial virulence factors?
( C, CW, E )
Capsules
Cell wall components
Enzymes
What are capsules, what do they help resist, and promote what?
Evade phagocytosis & promote attachement for a microbe
What are the 3 cell wall components in bacteria that are virulence factors?
Streptococcus pyogenes - protein M
Mycobacteria - mycolic acids
Neisseria gonorrheae- fimbriae
What’s another name for mycolic acid?
Acid fast bacteria
How does enzyme help virulence factors?
Breakdown and dissolve material found between cells
What are the 5 enzymes that help virulence factors ?
Hyaluronidase
Coagulase
IGA proteases
Streptokinase
Collagenases
What does hyalyronidase enzyme do? And breaks what acid?
Spreading factor ; invade in the body ; breaks hyalyronic acid
What Does coagulase enzyme do for virulence factors? (2, walls off what ?)
Increasing clotting ( coagulation )
&
Walls off microorganism from immune system
What is a bacteria that produces hyaluronidase enzyme?
Streptococci
What is a bacteria that produces coagulase?
Staphylococcus
What does IGA proteases do?
Destroy antibodies
What does streptokinase do?
Dissolve clots ( digests fibrin )
What is a bacteria that has streptokinase enzyme?
Streptococcus pyogenes
What are collagenases?
Break down collagen
What are examples of bacteria that produces collagenases?
Clostridia
How does hemolysis help virulence factors?
Hemolyses RBC
What are the 2 types of hemolysis? And what do they do & color
Alpha - partial digestion - green color
Beta - complete - clear color
What does leukocinds do for virulence factors, they are what type of cell, and are important for?
Destroys neutrophils
WBC for phagocytosis
What are examples for leukocidins bacteria?
(S, S )
Staphylococci and streptococci
If phagocytosis happens, will there be damage to host?
No
What are bacterial toxins?
Poisonous substances produced by microbes
What does toxins produce? Symptoms ?
Fever, shock, diarrhea
What is toxemia?
Presence of toxin in blood
What is intoxication?
Disease due to Ingestion of the toxin
What is exotoxins?
Produced inside bacteria and released into the surrounding medium
What is Endotoxin?
Lipid A portion of LPS released from cell wall of gram negative bacteria
What are the 2 groups of that toxins can be divided in?
Exotoxins & endotoxins
Exotoxins are for secretions ?
Yes
Where do exotoxins go and how do they get there?
Released by export Using bloodstream, they move and infect organs
Exotoxins are made of what?
Proteins
What’s another name for endotoxins ?
Lipid A
What are endotoxins made of?
Lipids
What is endotoxins mainly found in? Type of bacteria?
Gram negative
Are endotoxins part of the cell wall in bacteria?and what is it called ?
Yes, LPS
How are endotoxins released?
Cell lyses
What are the major effects of endotoxins ? (2)
Toxic shock
Fever
What does endotoxin activate ?
( clot??)
Clotting cascade
Blocking blood supply & tissue death
DIC
What does pyrogenic response mean?
Fever response
Does endotoxin cause pyrogenic response?
Yes, fever response
What are the steps of the endotoxins and the pyrogenic response? (6)
- Macrophage ingests gram negative bacterium by phagocytosis
- The bacterium is degraded & released endotoxins
- These endotoxins induce the macrophage to produce cytokines IL-1 & TNF
- these cytokines are released into bloodstream and travel to hypothalamus
- The cytokines induce the hypothalamus to produce prostaglandins
- Causing fever
What does IL-1 mean and cause?
Interleukin 1 ( endogenous pyrogen )
Causes the hypothalamus to produce prostaglandins
What does prostaglandins cause?
Raising of body temperature
What’s the main function of the hypothalamus?
Controls body temperature
So when IL-1 goes to the hypothalamus it produces and results in?
Produces prostaglandins & fever resulting
What does TNF do, cause and results in?
Vesal dilation of the blood vessels & dumping of fluid out of circulation
Blood pressure to drop and results in toxic shock
What are the 2 inflammatory chemicals that lipid A cause?
IL-1 and TNF
What is rapid decrease in blood pressure called?
Hypotension
What type of medications do you take to help with a fever?
IB PROF, Tylenol
When TNF+IL-1 activate other cells in the immune system, what does that release?
Mediators
What does TNF stand for?
Tumor necrosis factor
What are some examples of gram negative bacterium with endotoxins producers?
Proteus
Klebsiella
E. coli
Salmonella
Are exotoxins proteins or lipids?
Proteins
Can exotoxins be produced by gram positive or negative?
Both
Are exotoxins more lethal than endotoxins?
Yes, very
Do exotoxins have more acute results ?
Yes!!! More than endotoxins
What does the body produce that helps give immunity against exotoxins?
Anti toxins
What are toxoids?
They are used as vaccines and stimulates antitoxins
How do you destroy exotoxins?
Heat or by chemicals
Are exotoxins names according to the cell they attack? Give an example?
Neurotoxins
Cardiotoxins
Leukotoxins
What are exotoxins carried by?
Genes often carried on plasmids or bacteriophages
Because exotoxins are proteins, we can destroy them by?
Heat
Proteins give good antibodies response or lipids?
Proteins
Are toxoids toxic?
No
What is a denature exotoxin called?
Toxoids
exotoxins or endotoxins
Can we make toxoids?
Exotoxins
What’s an example of toxoids ( think of An animal ) ?
Anti venom
( against snakes, using that venom, destroy them, and make them into toxids to make vaccines )
Can endotoxins be destroyed by heat? Why?
No, because they are made of lipids
Why can we destroy exotoxins by heat?
Yes Cause they are made of proteins
Do toxoids cause disease?why?
No, because they are denature
Once a exotoxin is denature it’s called a ?
Toxoid
What are the 4 exotoxins ?
Diptheria
Erythrogenic
Botulinum
Tetanus
What is the diptheria toxin called?
Corynebacterium diptheriae
What does the diptheria toxin do?
Inhibits protein synthesis
Can diptheria kill? And destroys what?
Yes, destroys Heart and kidney cells
( resulting in heart & kidney failure, mainly cause of our death )
Is there a vaccine for diptheria?called?
Yes, D-TAP
Is the D- from D-Tap a toxoid? And how does it work?
Yes, that’s why we use this vaccine for diptheria
( toxoid helps make antibodies, these antibodies find the toxin when it’s produced and bloxk it from making any damage )
What is the bacteria for tetanus ?
Clostridium tetani
What is the first symptom of tetanus?
Lock jaw
What tetanus toxin inhibit?
Nerve cell impulses for muscles relaxation
Can we prevent tetanus ? How?
D-TAP vaccine
Is the T in D-TAP a toxoid?
Yes, we denature it so we can use it
What is the bacteria named called for botulinum?
Clostridium botulinum
How does botulinum toxin work? Inhibits what, and results in?
Inhibits the release of acetylcholine
- paralysis
What is the most potent neurotoxin ?
Botulinum
What is most associated with botulism?
Canned foods
When do symptoms for botulism show? How long?
12-46 hours
What are the two types of botulism?
Adult and infant
What is considered adult botulism? At what age?
2 years and older
How do you get adult botulism?
Canned foods that is improperly canned and contaminate by exotoxins
( injesting of preformed toxins )
What are some symptoms of botulism ?
Poor vision, difficulty in swallowing, weakness
What is the most potent exotoxins ?
Botulism
How does adult botulism occur? Do we need to ingest the preformed toxin or eat the endospores?
We need to ingest the preformed toxin
What is the prevention of adult botulism?
Boiling for 20mins
What is the treatment for adult botulism?
Trivalent antitoxin A, B, E
Why does boiling for 20mins canned food help prevent botulism?
Because exotoxins are made of proteins
Proteins can be denature by heat
What do we use botulism for?
Botox
How do babies get infant botulism?
Honey
If babies ingest the bacterium itself or the endospores, can they get sick ? But mainly?
Yes, but mainly eating the endospores
Unlike adults, can adults get sick from eating endospores of botulism?
No
Can adults get sick of injecting the pre formed toxin of botulism?
Yes
What are symptoms of infant botulism?
Floppy, crying, sucks poorly
What is the bacteria for erythrogenic toxin?
Streptococcus pyogenes
What does erythrogenic toxin do and cause?
Damage blood capillaries
Rash of scarlet fever
