test 4 Flashcards
What will secrete exotoxin?
Gram + and/or gram - bacteria.
Where else will exotoxin come from besides being secreted by gram + and Gram - bacteria?
It can leak into the surrounding fluid following lysis of a bacterial cell.
What do bacteria need to do to produce enough exotoxin to be harmful?
The bacteria must colonize tissue.
How are exotoxins made with foodborne illnesses?
The bacteria multiples in the food and produces exotoxins.
What are most exotoxins made of?
Proteins.
How will the immune system respond to exotoxins that are proteins?
Make antibodies.
Many exotoxins are so powerful that fatal damage can occur before what happens?
An immune response is mounted.
Why are vaccinations against exotoxins so valuable?
For those that are so powerful they cause fatal damage before an immune response is mounted the vaccines are invaluable for quick memory response.
What will heat do to exotoxins?
Since most of them are proteins heat will kill them.
Exotoxins are released by every major Gram positive genera except what?
Listeria.
Many bacteria that release exotoxins also release what?
Endotoxin.
Will exotoxins cause a fever or generalized inflammation?
Not usually.
What are the 3 specific targets of exotoxins?
Neurotoxins, Enterotoxins, Cytotoxins.
What do neurotoxins do?
cause paralysis.
What do enterotoxins do?
Act of GI tract to cause diarrhea.
What do Cytotoxins do?
Damage a variety of cell types by interfering with cell mechanisms or causing cell lysis.
Endotoxins are what?
Lipopolysaccharides (LPS).
What are LPS’s composed of?
Lipid A, core polysaccharide, O specific polysaccharide.
LPS is a molecule that is part of what?
Outer membrane in Gram Negative bacteria.
LPS’s are fundamental parts of what?
The cell wall of gram negative bacteria.
The immune response to endotoxins is due to what?
Innate immune response, no specific target.
what will heat do to endotoxins?
It will not be destoryed.
What will autoclaving do to endotoxins?
Not destroy them.
Name the 2 Gram positive Cocci?
- Staphylococcus. 2. Streptococcus.
Will staphylococcus be part of our normal flora?
Yes.
What are the 2 types of Staphylococcus mentioned?
- S. Aureus. 2. Staphylococcus epidermidis.
What will the S. aureus pigment be like?
Golden.
What is the coagulase like for S. aureus?
Positive.
What are the virulence factors of S. aureus?
Protein A, and Exotoxins.
What is protein A?
Extracellular surface protein that binds to IgG’s and prevents organization by coating bacterium with host immunoglobin.
With S. aureus what is the most potent hemolysin?
Alpha toxin.
What will cause Toxic shock syndrome toxin?
An exotoxin from S. aureus.
What will toxic shock syndrome do?
A superantigen causing release of cytokines which cause a drop in blood pressure and kidney damage.
Toxic shock syndrome was initially associated with what?
Tamon use.
S. Aureus causes enterotoxin which is what?
An exotoxin if present in food will cause nausea and vomiting if consumed.
Since Enterotoxin from S. aureus is an exotoxin will heat kill it?
No it is heat stable.
S. aureus causes Exofoliatin which is what?
An exotoxin that destories material that binds together the layers of skin.
What are the different pathogenesis of S. aureus?
Furuncles (boils)folliculitis, scalded skin syndr, toxic shock syndr, Pneumonia, soteomyelitis, catheter and shunt infections, wound infections, MRSA
What is the coagulase like for staphylococcus epidermidis?
Negative.
What is staphylococcus epidermidis like?
opportunistic pathogen.
What type of patients get staphylococcus epidermidis?
Compromised patients.
What is the treatment like for Staphylococcus?
Difficult since almost all strains produce penixillinase (beta-lactamase).
What type of media is needed for streptococcus growth?
Rich media. So little or no growth on a traditional media.
All streptococci can be identified in what way?
Hemolysis patterns.
What are the 3 different Hemolysis patterns of streptococcus?
Alpha-, Beta-, and Gama-hemolysis.
How can you tell you have a alpha-hemolysis?
Partial hemolysis with greenish cast around colonies.
How can you tell you have a beta-hemolysis?
Complete lysis of blood cells creating clear area around colonies.
How can you tell you have a gama-hemolysis?
no lysis of blood cells.
What are Lancefield groups?
Ways to catagorize streptoccus bacteria that is not inclusive and used to some degree still.
What groups of Lancefield are used today?
Groups A and B.
What is a more inclusive way to classify strep?
By dividing into 4 groups.
What are the 4 inclusive groups that streptococcus can be divided into?
lactic, fecal, viridans, Beta-hemolytic.
What is the lactic streptococci like?
Non pathogenic, no hemolysis.
Where is Lactic streptococci found at?
In milk products.
What is lactic streptococci used for?
in dairy fermentation, produce lactic acid that gives sour taste to foods.
Fecal streptococci is found in what Lancefield group?
D.
Fecal streptococci is normal flora of what?
The intestinal tract.
What are the hemolysis patterns of fecal streptococci like?
Different patterns than alpha, beta, and gamma.
Fecal streptococci is clinically a cause of what?
Urinary infections, sometimes endocarditis.
Fecal streptococci is what type of pathogen?
Opportunistic pathogen that causes disease in weakend patients.
What is another name for Fecal streptococci?
Enterococci.
What is VRE?
Vancomycin resistant enterococci. A type of fecal streptococci that is resistant to vancomyocin.
What type of group is viridans streptococci?
Large heterogenous group.
What type of Lancefield antigens will Viridans streptococci have?
None.
What type of hemolysis will Viridans streptococci have?
Alpha.
Viridans streptococci is normal flora of what?
The mouth and respiratory tract.
Viridans strptococci may cause what?
Tooth decay, and bacterial endocarditis (patients that have heart damage or heart condition).
Beta-hemolytic streptococci has strains in both the group A and B of the lancefield groups and what will these strains be?
Group A- Streptococcus pyogenes. Group B- Streptococcus agalactiae.
What is the major pathogen of streptococcus?
Streptococcus pyogenes.
What type of toxin will Streptococcus pyogenes have?
Pyrogenic exotoxins.
What are the pyrogenic exotoxins like with Streptococcus pyogenes?
M protein, hyaluronic acid capsule.
What are the different pathogenesis of Streptococcus pyogenes?
Streptococcal pharyngitis, Streptococcal impetigo, cellulitis, erysinpelas, Scarlet fever, post streptococcal diseases.
What are post streptococcal diseases?
Rheumatic fever, Glomerulonephritis.
What is St. Anthony’s fire?
Erysipelas which is a pathogenesis of Streptococcus pyogenes.
What are 3 ways to diagnose sterptococcus pyogenes?
blood agarplates, Sensitive to bacitracin, ELISA test.
Name 2 other pathogens of streptococcus?
S. agalacitiae, and S. Pneumoniae.
Streptococcus agalactiae is normal flora of what?
Female geintal tract in 10-30% of females.
Colonization of Streptococcus agalactiae is like what?
Transient.
Streptococcus agalactiae is an important cause of what?
Neonatal meningitis, pneumonia, sepsis in first week of life= high mortality.
What will the capsule for Streptococcus pneumoniae be like?
Polysaccharide.
What is the purpose of the S. pneumoniae polysaccharide capsule?
Major virulence factor and antigenic.
What hemolysis group will S. pneumoniae be in?
Alpha.
S. pneumoniae is part of the normal flora in what % of people?
5-40%.
Infection occurs when with Streptococcus pneumoniae?
If invasive strain moves to lower lungs.
Streptococcus pneumoniae is the most common cause of what in adults?
Pneumonia, acute onset with chillsm and high fever. And meningitis.
What will the difference between adult and infant meningitis caused by Streptococcus pneumoniae?
Adults stiff necks and no stiff necks in infants.
Streptococcus pneumoniae is a common cause of what in children?
Otitis media and sinusitis.
How will Streptococcus pneumoniae be diagnosed?
Quellung reaction.
What is the quellung reaction?
Mix sample with serum containing antibodies to capsular antigens capsules appear to swell.
What is the treatment for Streptococcus pneumoniae?
Polyvalent vaccine and conjugate vaccine.
All members of Neisseria are what?
Gram negative diplococci and are oxidase positive and fastidious.
What is Fastidious?
Picky eaters.
What are the virulence factors for Neisseria gonorrhoeae?
Pili, Gram negative cell wall LOS (similar to LPS), secreted protease IgA that destroys immunoglob A, and membrane proteins that adhere to host cell.
How is Neisseria gonorrhoeae acquired?
Through unprotected sexual intercourse.
What happens to Males who acquire Neisseria gonorrhoeae?
It penet the mucous membrane of the urethra causing inflam, and they frequently experience pain on urination and purulent discharge from urethra.
Will any males with neisseria gonorrhoeae remain asymptomatic?
Yes.
What happens to females who acquire neisseria gonorrhoeae?
Most remain Asympotomatic and are reservoirs for disease.
Females who are not asymptomatic with neisseria gonorrhoeae will experience what?
Painful urination and discharge, It will infect cervix or rectum. Can cause pelivic inflammatory disease.
What part of the female body can not be infected with neisseria gonorrhoeae?
The vagina.
How will infants get neisseria gonorrhoeae?
Transmitted from mother to infant during childbirth.
What will Neisseria gonorrhoeae do to infants?
Damage cornea and lead to blindness.
How will Neisseria gonorrhoeae be diagnosed?
Oxidase test.
What is the treatment for Neisseria gonorrhoeae?
Penicillin is no longer effective due to PPNG. Tetracyline for concurrent Chlamydia infection, Prophylaxis- to treat eyes of newborns.
What are the virulence factors for Neisseria meningitidis?
Polysaccharide capsule, Endotoxin, Secreted protease (IgA protease=cuts up IgA).
What is the host for Neisseria meningitidis?
Humans are the only natural hosts.
Who is at high risk for neisseria meningitidis?
Kids 6 months to 2 years, and army boot camps 40% carriers.
Can there be healthy carriers of neisseria meningitidis?
Yes 5% of people this is in their normal flora.
What is menigococcemia?
Neisseria meningitidis bacteria invade bloodstream from nasopharynx and this can result in deadly sepsis.
What is the classic clue of menigococcemia?
Appearance of petechial rash called purpura.
What is waterhouse friderichsen syndrome?
A septic shock from neisseria meningitidis bacteria causing a systemic immune response that leads to bilateral hemorrhage into adrenal glands.
How is Neisseria meningitidis diagnosed?
Culture body fluids, oxidase test.
What is the treatment for neisseria meningitidis?
Elimination of carriers, penicillin, vaccine available but not widely used.
What type of bacteria is clostridium?
Gram positive endospore forming rods.
What type of metabolism will colstridium have?
Anaerobic.
Where will clostridium be found at?
Since it has an endospore it is found in soil and water.
What are 2 ways to get clostridium perfringens?
Food poisoning, gas gangrene.
What are the 2 types of food poisoning from clostridium perfringens?
enterotoxin A- Diarrhea, cramping. Enterotoxin C- hemorrhagic enteritis= tissue damage and bleeding.
What will gas gangrene from clostridium perfringens do?
Exotoxin that destroys muscle, and produces gas.
How is clostridium perfringens diagnosed?
Egg yolk agar, anaerobic culture.
What is the treatment for clostridium perfringens?
Surgical cleansing (debridement), penicillins.
Clostidium botulinum will cause what?
Botulism.
What will botulism cause?
Flaccid paralysis by blocking cholinergic synapse by 7 neurotoxins.
What types of botulism will clostridium botulinum cause?
Adult and infant.