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.
How is clostridium botulinum diagnosed?
Inject mice with serum from patient or left over food if toxin is present mice will die rapidly. In infants toxin can be id in bowel content, not serum.
How can clostridium botulinum be prevented?
Cook food in canned pressure cookers above 212 F or 100 C for 10 minutes.
Clostridium tetani causes what?
Neurotoxins block inhibitory impulses to muscles and cause muscles to spasm and contraction-tetany.
What is opisthotonos?
Spasm in back muscles-head is thrown backwards and the back is bowed like an arch from clostridium tetani.
How is clostridium tetani prevented?
Toxoid (weakend toxin) vaccine, part of DTP.
What will clostridium difficile cause?
Pseudomembranous colitis.
What is pseudomembranous colitis?
A severe infection of the colon.
Pseudomembranous colitis often occurs when?
After normal gut flora is eradicated by the use of antibiotics.
How will clostridium difficile react to antibiotics?
Most strains are resistant that?s why when antibiotics kill off a lot of normal flora that clostridium difficile flourishes.
What is the treatment of Clostridium difficle?
Discontinue antibiotics, and treat with metronidazole, 2nd choice vancomycin.
Should you give a patient loperamide and bismuth who has clostridium difficel?
No because slowing of fecal transit time is thought to result in extended toxin-associated damage.
What is Bacillus like?
Gram positive endospore forming rods.
What is bacillus metabolism like?
Aerobic.
Bacillus is endospore forming that has what type of pattern?
Bamboo-like pattern.
What are the 3 types of bacillus anthracis?
- Cutaneous anthrax. 2. Gastroinetsinal anthrax. 3. Inhalation anthrax.
Cutaneous anthrax is aka?
Woolsorters disease.
How common is cutaneous anthrax and how is it aquired?
Common and endospore enters a cut.
How common is GI anthrax and how is it aquired?
Uncommon and from uncooked or contaminated meat.
How is inhalation anthrax aquired?
spores inhaled into alceoli, ex-sporulate and release toxins.
What are the symptoms of inhalation anthrax?
non-specific symptoms.
What is the treatment for Bacillus anthracis?
After exposure oral ciprofloxacin. Before exposure there is a vaccine.
How was the Bacillus anthracis vaccine made?
From an attenuated strain of Bacillus anthracis.
What will bacillus cereus cause?
There are 2 types of enterotxins 1. Diarrheal. 2. Vomiting.
Name 2 gram positive non-endospore forming rod bacteria?
Corynebacterium diphtheriae, and Listeria monocytogenes.
What is the primary reservoir for corynebacterium diphtheriae?
Humans.
What are the sources of infection of corynebacterium diphtheriae?
Carriers who have recovered, New cases not exhibiting symptoms, people with active disease, contaminated articles.
Where will Corynebacterium diphtheriae localize at?
In throat and cause swelling of the neck.
What will corynebacterium diphtheriae do once localized in the throat?
Forms a gray membrane composed of clooted blood, epithelial cells and leukocytes.
Corynebacterium diphtheriae produces toxins that do what?
Cause nerve damage= paralysis of soft palate and eye muscles. Toxin can be absorbed in blood and damage kidneys, heart, and extrem nerve damage.
What is the major concern with the gray membrane in the throat?
It can become detached and cause suffocation.
How is corynebacterium diphtheriae diagnosed?
Schick test
What is the treatment for corynebacterium diphtheriae?
Antitoxin.
How is corynebacterium diphtheriae prevented?
Immunization DPT.
When will Listeria Monocytogenes be motile?
at 22-28 degrees C. Not at body temps.
Where is Listeria monocytogenes found at commonly and why?
Deli meat because it grows well at 4 Degrees C in a refrigerator.
Listeria is ____ hemolytic?
Beta.
What is unique about Listeria monocytogenes?
It produces endotoxin and is gram +.
How is Listeria monocytogenes aquired?
Ingested in contaminated food.
Who is at high risk for listeria moncytogenes?
Immunocompromised people, and pregnant women and neonates.
Why are neonates at risk for listeria monocytogenes?
Contact microbe from asymptoma mother during delivery, and Listera can cross the placental barrier result in miscarriage or delivery of crit ill neonate.
Name the 7 gram negative bacteria also known as enterics.
- E. coli. 2. K. Pneumoniae. 3. Enterobacter. 4. Serratia. 5. Proteus. 6. Salmonella. 7. Shigella.
How many gram negative bacteria aka enterics are considered coliforms?
- E. coli, K. Pneumoniae, and enterobacter.
What are coliforms?
Facultatively anaerobic, gram negative, non-endospore forming, rod shaped bacteria that FERMENT LACTOSE with gas production.
Coliforms are normally found where?
Human intestines.
Where should coliforms not be found?
Outside of intestines.
Coliforms are used as an indicator of what?
Water quality testing.
What type of pathogen is escherichia coli?
Opportunistic.
How can DNA transfer from E. coli?
via conjugation, transposons, lysogenic converion.
What will E. coli infections cause?
Septicemia, UTI, meningitis, Gastroenteritis.
Gastroenteritis is caused by what 4 things?
- Enterotoxin producing E. coli. 2. Enteroinvasive E. coli. 3. Enteropathogenic E. coli. 4. Enterohemorrhagic E. coli.
What is enterotoxin producing E. coli?
Traveler’s diarrhea.
What is Enteroinvasive E. coli?
E. coli invades intestinal cells.
What is the main virulence factor with Enteroinvasive E. coli?
Encoded on plasmid shared by shigella and E. coli.
What will enteroinvasice E coli cause?
Produces shiga-like toxin which causes gastroenteritis.
What will enteropathogenic E. coli do?
Will not invade cells, but adheres to them.
Once Enteropathogenic E. coli adheres to cells what will it do?
Coded on the plasmid once it adheres it causes loss of microvilli where microbe attaches and causes non-bloody diarrhea.
Almost all enterohemorrhagic E. coli belong to what group?
serotype o157:H7.
What will enterohemorrhagic E. coli do?
Produce a toxin known as verotoxin.
What will verotoxin do?
Blocks a cellular protein that normally prevents the cell from entering apoptosis.
What disease is associated with Enterohemorrhagic E. coli?
E. colio157:H7.
What will the gastroenteritis caused by enterohemorrhagic E. coli be like?
Severe abdominal pain and diarrhea which initially is watery, but becomes grossly bloody with occaisonal vomiting.
Some victims of Enterohemorrhagic E. coli develop hemolytic uremic syndrom (HUS) and this is characterized by what?
Renal failure and lysis of RBC’s.
What % of hemorrhagic colitis victims develop HUS?
0-15%.
How is Escherichia coli diagnosed?
It produces a green metalic sheen on EMB agar
How can Escherichia coli be distingushed from Enterobacter?
use IMViC.
Klebsiella pneumoniae is a coliform that is classified by what?
Capsule antigens.
K. pneumoniae effects who and when?
The second most common cause of sepsis in hospitilized patients.
People with K. pneumoniae get what type of infections?
Urinary caused by Foley catheters, and infant septicemia.
Enterobacter is a coliform, but what is the most common species among the enterobacter?
Enterobacter aeruginosa.
What can Enterobacter aeruginosa cause?
(UTI) urinary tract infects.
Can serraita ferment lactose?
No it is not a coliform.
Serratia is noted for it’s characteristic what?
Red pigment (only 10% of isolates).
Serratia is an opportunistic pathogen in hospitilzed patientes that causes what problmes?
Pneumonia, bacteriemia, endocarditis.
Can proteus ferment lactose?
No it is not a coliform.
Proteus is an opportunistic pathogen that has what type of unique feature?
Swarming on agar.
What type of unique enzyme will proteus have and what will it do?
Urease and it breaks down urea to produce cherry red color.
Will salmonella be part of the normal flora?
No.
Can Salmonella ferment lactose?
No it is not a coliform.
What will salmonella cause?
Typhoid fever.
Typhoid fever is aka?
Enteric fever.
Typhoid fever is only caused by a few types of salmonellae, but which one is the most important?
Salmonella typhi.
How can people get typhoid fever?
Humans are reservoirs and it is through fecal-oral transmission. Water and food contaminated with feces and/or urine.
Will people still be carriers of typhoid or salmonella after they recover from typhoid fever?
Yes in the gallbladder.
With salmonella will a large or small dose be needed to cause disease?
Small.
Salmonellosis starts how long after exposure to salmonella?
1-3 weeks.
What will salmonella do once inside of people?
Invades intestinal cells and then moves into lymph nodes.
From the lymph nodes bacteria can do what?
can infect multiple systems esp. spleen.
What happens to salmonella that are phagocytosed by monocytes?
They can survive and divide inside the phagocytes.
What is it called when bactria can survive inside of phagocytes?
Facultative intracellular parasite.
What are the symptoms of typhoid fever?
Abdominal pain, headache, weakness, high fever, rose colored spots on chest and/or abdomen.
How is typhoid fever or salmonella infections diagnosed?
Culture blood, urine or feces to determine serotype.
What is the treatment for typhoid fever?
Chloramphenicol, cipro, ampicillin.
Someone with typhoid fever that is being treated with antibiotics should also have what?
IV fluids, electrolytes.
How can typhoid fever be prevented?
There is a vaccination that is recommended for travel outside of the USA, Canada, Northern-Europe, Australia, and New Zealand.
What is the most common type of salmonella infection?
Gastroenteritis.
How can we get gastroenteritis type of salmonella infection?
Animals are reservoirs of infection including chickens, domestic animals, reptiles, cows. Commonly associated with undercooked eggs.
How will gastroenteritis salmonella infect eggs?
Silently infects ovaries of healthy appearing hens and contaminates the eggs before the shells are formed.
What type of toxin will gastroenteritis salmonella have?
Both endotoxin and enterotoxin.
What is the gastroenteritis salmonella enterotoxin like?
Cholera-like.
What is the treatment for gastroenteritis salmonella?
Fluids and electrolytes.
Why wont you give antibiotics to gastroenteritis salmonella infections?
They don?t shorten the course of disease.
How long will diarrhea last with gastroenteritis salmonella last?
a week or less.
Shigella is an enteric, but is it part of the normal flora and can itferment lactose?
It is not part of normal flora and can’t ferment lactose because it is not a coliform.
When will shigella be pathogenic?
Always.
There are 4 species of Shigella, but which one is the most pathogenic?
Shigella dysenteriae.
What will shigella dysenteriae cause?
Bacterial dysentery.
How can we get bacteral dysentery from shigella dysenteriae?
Humans are the only reservoir for disease and it comes from fecal-oral transmission(food, fingers, feces, and flies).
What will stomach acids do to bacterial dysentery caused by shigella?
Not easily killed so infectious dose is low.
Shigella dysenteriae produce potent enterotoxin called what and what will it do?
Shiga toxin and it kills epithelial cells, but rarely invades bloodstream.
What will bacterial dysentery cause?
Severe inflammatory response causing bloody diarrhea.
Shiga toxin can cause what?
Hemolytic uremic syndrome which is often fatal.
How are shigella infections diagnosed?
SS agar (selective and differential).
A selective and differential SS agar is done do distinguish Shigella from what?
Salmonella.
Name 2 pleomorphic gram negative rods with bipolar staining?
- Yersinia pestis. 2. Yersinia enterocolittica.
Yersinia bacteria are motile and are part of what family?
Enterobacteriaceae family.
Yersinia pestis caused what?
Bubonic plague.
The bubonic plague caused how many major epidemics?
Three.
Where wil yersinia pestis come from?
It is endemic in rodent populations of all continents besides Australia and is transmitted by rat fleas.
What does the word sylvan mean?
Pertaining to the woods or wild.
The bubonic plague is classified as what type of disease?
Zoonosis.
What happens to Yersinia pestis after bacteria enter via a flea bite?
Engulfed by macrophages where they multiply and are carried to lymph nodes.
What happens to lymph nodes with macrophages with yersinia pestis?
They become swollen and are called buboes.
What happens to lymph nodes once buboes are formed?
The lymph nodes become necrotic allowing large numbers of bacteria to enter the blood-septicemic plague.
What is septicemic plague?
Endotoxin results in shock and disseminated intravascular coagulation.
What is the mortality of septicemic plague?
75%.
What happens in 10-20% of septicemic plagues?
Infection of the lungs from bloodstream and this causes Pneumonic plague.
What happens to people with the pneumonic plague?
Always fatal in just a few days.
What is the prevention and control of Yersinia pestis?
Control of rat population and antibiotic treatment.
How is yersinia enterocolitica transmitted?
Fecal-oral. Ingestion of contaminated food or water.
What type of toxin will yersinia enterocolitica have?
Heat stable enterotoxin that leads to severe gastroenteritis.
Name 3 Gram negative rods that are found widely in nature?
- Vibrio. 2. Campylobacter. 3. Helicobacter.
Vibrio cholerae is a _____ gram negative rod.
Curved.
What type of flagellum will Vibrio cholerae have?
Single polar flagellum that appears to vibrate.
What will confer serologic specificity of Vibrio cholerae?
O lipopolysaccharides.
Vibrio cholerase has at least how many O antigen groups?
at least 139.
Strains of O group 1 and O group 139 cause what?
Classic cholera.
Within O group 1 how many biotypes have been identified?
2 classic and E1 for vibrio cholerae.
O1 and E1 biotype for vibrio cholerae is similar to what?
Vibrio cholerae 0139.
What will stomach acids do to Vibrio cholerae?
Kills it so large amounts are needed to be infected.
60% of infections of classic biotype of vibrio cholerae are what?
Asymptomatic.
75% of infections of E1 biotype of vibrio cholerae are what?
Asymptomatic.
For those who become infected with vibrio cholerae incubation period is how long?
1-4 days.
What do Vibrio cholerae do once inside?
Adhere to mucosa and multiply, but do not invade the cells.
What is Choleragen?
An enterotoxin produced by vibrio cholerae.
Choleragen causes what?
Increased production of cAMP.
Accumulations of cAMP cause what?
It causes intestinal cells to convert them into little pumps that continuously secrete Cl_ ions accompanied by other ions and water.
What else will Choleragen do?
Inhibits absorption of Na+.
How is Vibrio cholerae prevented?
Sewage treatment and water purification, good food hygiene.
How is Vibrio cholerae treated?
Fluid replacement using oral rehydration salts and in severe casees IV’s.
What is the shape of campylobacter?
Spiral shaped with unipolar/bipolar flagella.
Campylobacter is the major cause of what?
Gastroenteritis in the USA (among the top 3).
What is the treatment for campylobacter?
It is self limiting and lasts 5-8 days.
What is the shape of helicobacter?
Spiral shaped with unipolar sheathed flagella.
Helicobacter is the 2nd leading cause of what?
Gastric/duodenal ulcers.
How can Helicobacter survive the stomach acids?
They produce urease which allows them to create an alkaline microenvironment.
How is Helicobacter treated?
Antibiotic therapy combined with bismuth.
Name 2 obligate anaerobic gram negative bacteria?
- Bacteroides fragilis. 2. Fusobacterium.
What is the shape of bacteroides fragilis?
Rod shaped.
Bacteroides fragilis is a major component of what?
normal flora of GI tract (99%).
Besides GI tract where will bacteroides fragilis be found at?
Mouth and femal genitourinary system.
What is cell wall of bacteroides fragilis like?
No endotoxin even though gram negative so cell wall is not toxic.
Will bacteroides fragilis possess a capsule?
no.
Can bacteroides fragilis be a pathogen?
Yes an opportunistic pathogen.
When will bacteroides fragilis be an opportunistic pathogen?
If intestine is perforated it will cause abscesses in peritoneum, and in female genitourinary tract.
Bacteroides fragilis is implicated in what disease?
Periodontal disease.
Fusobacterium is similar to what?
Bacteroides.
What s the morphology of fusibacterium?
Long rods with tapered ends.
Fusobacterium is part of what?
Normal flora.
Can fusobacterium be a pathogen?
Yes an opportunistic pathogen.
Fusobacterium is an opportunistic pathogen that causes many infections, but which one is most notable?
Aspiration pneumonia.
How is aspiration pneumonia aquired?
Result of inhaling bacteria from aspirated vomitus.
Name the 1 obligate aerobic gram negative rod in the notes?
Pseudomonas aeruginosa.
Pseudomonas aeruginosa is the epitome of what?
Opportunistic pathogens.
Pseudomonas aeruginosa will not effect who?
Healthy patients.
Psudomonsa aeruginosa infects what type of tissue in weakened patients?
Nearly any tissue.
Pseudomonsa aeruginosa is a major cause of what?
Nosocomial infection.
What type of pigment will pseudomonas aeruginosa make?
Blue-green that resluts in blue-green pus and smells sweet.
How motile will Pseudomonas aeruginosa be?
Highly motile.
What will the outside of pseudomonas aeruginosa be like?
Produces slime layer.
Pseudomonsa aeruginosa have pili for what?
Exchange of antibiotic resistant plasmids.
What type of toxins will pseudomonas aeruginosa have?
Endotoxin and exotoxins and Leukocidins.
What are Leukocidins?
They inhibit immune response by killing white blood cells, notably neutrophils.
Pseudomonas aeruginosa is particularly problematic for who?
Burn victims, cystic fobrosis patients and any compromised individual (common in AIDS patients).
What is the treatment for pseudomonas aeruginosa?
Limited due to multiple resistance.
Prevention is key in pseudomonsa aeurinosa which is done by what?
Cleaning and monitoring of hospital equipment.
