MCB Exam 3 – Flashcards
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Unlock answersStrep and Staph are both gram _________.
|
| + Cocci |
| Strep is in _____________ while Staph is in _____________. |
Chains Clusters |
| N. Gonorrhea is classified as a gram _____________ |
| - cocci |
| Why are gram - bacterias harder to trea? |
| The outer membrane have the porins that make it more resistance to treat because they are so selective and dont allow certain things to get in. |
| ________________ and _______________ are examples of Gram + Bacilli. And are rods in chains. |
Bacillius Clostridium |
| When it comes to O2 source, Bacillus is ________________ while Clostridium is __________. |
Aerobic Oligate Anaerobe (grows in deep body parts) |
| Gram - Bacilli are ___________________that are in short rods that cause many diseases. Example are E.Coli, Shigella, Salmonella. |
| Enterobacteriaceae |
Cholera = _______________ Syphillis = _______________ |
Vibril Spirochete |
| Streptolysin O lyses ____________ and releases ________________. |
RBC HgB |
| An infection with ______________ will develop an antibody to Streptolysin O and thus will have ____________ RBC. |
Strep. Pyogenes Intact |
| List the Gram + spore-forming anaerobic bacilli.. |
Clostridium Perfringenes C.Tetani C.Botulinum C. difficile |
| What does CDAD stand for? |
| Clostridium Difficile-Associated Diarrhea |
| What happens with Pseudomembranous colitits? |
| The bacteria disrupts the normal flora and colonizes. It produces Toxin A and B which damages the tissues and causes excessive growth and leads to an enlarged colon. |
| What are some ways to diagnose CDAD? |
|
| _____________ may occur in 1/5 of CDAD patients. |
| Relapse; occurs within 1-3 weeks after termination of Rx and is with the same strain. |
| What are some characteristics of gangrene? |
|
| What is the bacteria that causes gas gangrene? |
| C. perferinges |
| Botulinum is an ________ and _______________ which makes the most toxic compounds. |
Exotoxin Nuerotoxin |
| C.Botulinum causes _______________ whereas C.Tetani causes _______________. |
Constant relaxation Lockjaw = constant contraction |
| Streptococus spp. is classified according to: |
Hemolysis pattern on blood agar Serological properties Biochemical properties
|
Beta hemolysis ____________ lysis RBCs. Alpha hemolysis ____________ lysis RBCs. Gamma hemolysis _______________. |
Partially Completely does not harm. |
| Classification o beta hemolytic Streptococci is based on _______________. There are _____ and ____ groups. |
C-carbohydrate (need an antigenic analysis of extracted carbohydrate)
A and B groups |
| An example of an A group Streptococci is _______________while an example of a group B Streptococci is _____________. |
S.Pyogenes S. Agalactiae |
| S.Pyogenes is part of the normal flora found in ___________, ___________ and _______. |
Mouth Throat Resp. tract |
| What type of diseases can occur with a S.Pyogenes infection? |
1. Skin infection 2. Respiratory infection 3. Invasive systemic infection (can spread via lympth and cause tissue damage) |
| List some examples of diseases that occur with S.Pyogenes infection. |
Pharyngitis (strep throat) Tonsillitis Scarlet fever Rheumatic fever Impetigo Cellulitis Bactermia Necrotizing fasciitis |
| What are the virulence factors of S.Pyogenes? |
1. Pili 2. M protein 3. Capsule 4. Streptolysin S and O 5. Hyaloronidase 6. Pyrogenic extotoxins 7. Bacteremia |
| What is special about the M protein on the S. Pyogenes? |
| It is anti-phagocytic |
| Hyaloronidase is aka _______________ because they break dwon _____________.. |
Spreading factor Connective tissue |
| Pyrogenic exotoxins are responsible for producing a ________ whereas bacterimia spreads the infection thru the ____________. |
Fever Blood system |
| If you have fluid vesicles, pustules, yellowish crust and pus filled lesions you have? |
| Impetigo |
| Which disease can be caused by both a Strep and Staph infection? |
| Impetigo |
| If you have a rash, flushed face and witish coating on tongue then you have this? |
| Scarlet fever |
| If you have carditis, polyarthritis, chorea, subq nodules and can lead to heart problems you have this? |
| Rheumatic fever |
| If caught early, _____________ works best for treating the flesh eating bacteria. If not then you have to remove the dead tissue. |
| Penicillin |
| What are the virulence factors for group B Streptococci? |
Petidoglycans Capsule Hydrolytic enzymes = Proteases, lipases, amylases that destroy all polymers. |
| What are some diseases that can occur with Group B Strep? |
Puerperal sepsis Pneumonia Meningitis |
| What is a CAMP test? |
| A blood test that diagnoses btwn staph and strep. and distinguishes btwn group A and group B strep infections. |
| S.Pneumoniae is ____________ hemolytic and is more _____________- than toxigenic. |
Alpha Invasive |
| ____________ are a major virulence determinant in S.pneumoniae |
| Capsules |
| What are some predisposing factors for S.pneumoniae disease? |
Anything that interferes with: The cough reflex the epiglottal reflex Cilliary action |
| What are some characteristics of enterobacteriaceaes? |
1. Non-spore forming 2. Faculative 3. Short rods 4. Gram - 5. Ferment glucose with acid +/- gas |
| Antigenic characteristics of Enterobacteriaceae include: |
O = somatic K = capusle H = Flagella |
| Name enterbacteriaeae that cause can which disease. |
E. coli = GI and UTI infections Klebsiella = pneumonia, and UTI Salmonella = Typhoid fever (severe form) Proteus = UTI
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| What is a bacterocult and how do you read results? |
Used to detect with pathogen if any caused an UTI infection. You phenol read indicator if you have a colony <25 then no infection. if colony 25-50 may have infection If colony > 50 then def have an infection |
| When using phenol red if you have urea your pH will ___________and you will see a _________ color. If you have lactose then your pH will ____________ and you see __________ color. |
Increase Pink Decrease Yellow |
| Which 3 organisms cause UTI and which is the main one? |
E.Coli (main) Klebsiella Proteus |
| Which toxins of E.Coli act like virulence factors? |
Heat labile (LT1 and II) Heat stable (STa and STb) Shiga like (STL I and STL II) = bloody diarrhea Hemolysin |
| What does ETEC stand for? |
| Entertoxigenic E.Coli |
| How does ETEC cause watery diarrhea? |
Has 2 toxins (LTI n II) and (Sta n b). LT increase cAMP while St increases GMP these cause ions to be lost and water follows.
Both interfere with the uptake of ions |
| Severe diarrhea from E.coli is caused by which toxin? |
Shiga like toxin Can cause bloody diarrhea |
| What does EHEC stand for? |
| Enterohemorrhagic E.Coli |
| How does the Shiga like toxin work in E.coli? |
| It is an A- B toxin that disrupts protein synthesis in eukaryotic cells. |
| What is the most serious result of an E.Coli infection? |
HUS Hemolytic Uremic syndrome |
| Which strain of E.Coli is mostly likely cause of HUS? |
| O157:H7 |
| How is Shigella usually transmitted? |
| Fecal-oral route |
| How does the Shigella disease spread? |
| Enters the small intestine, multiplies and travels to ileum and colon. Attaches to invades the M cells of the Peyers patche. Can spread to cells via epithelial cells. |
What are the possible pathogenesis outcomes of bacteria transmitted by the enteric route? |
1. Mucosal adherence 2. Mucosal invasion 3. Mucosal translocation |
| What are some features of mucosal adherence? And give an example of an organism that does this. |
Production of enterotoxin No invasion or lesions Watery diarrhea
Ex: Vibrio Cholerae |
| What are some features of mucosal invasion and provide an example of an organism that does this. |
Cells are invaded, bacteremia is less common Have observable lesions Diarrhea with blood or pus is possible
Ex: Enteropathogenic E.Coli and Shigella |
| What are some features of mucosal translocation and give an example of an organism that does this? |
Bacteria passes thru the mucosal layer Spreads thru body in macrophages Symptoms such as fever, shock
Ex: Salmonella typhi (survive phagocytosis) |
| What are some methods to detect the presence of an enterotoxin? |
1. rabit ileal loop test 2. Infant mouse lethality 3. Enzymatic tests |
| List some methods used to detect invasiness. |
1. Production of keatoconjunctivitis (guinea pig eyes) 2. Invasion of cells in tissue culture |
| What type of diseases can Salmonella cause? Which is the mildest? the most severe? |
1. Gastroenteritis (mildest) 2. Septicemia 3. Enteric fever (most severe) |
| What are characteristics of extra intestinal disease caused by Salmonella? |
Septicemia Fever, Shock, lesions in the kidneys and lungs GI symptoms may be low Pediatric and Geriatric are greater risk |
| What are some characteristics of enteric fever caused by Salmonella? |
Most sever form of infection = Typhoid fever Invades the Intestinal tract, penetrates the wall enter lymph nodes. Dont get killed by phagocytes so they multiply and reenter the blood stream (fever, shock from endotoxin). Can reenter intestine and cause diarrhea and infect gall bladder also. Frequently fatal |
| T/F: There is a vaccine in the form of killed bacteria available for S.typhi. |
| true |
| Name a disease caused by Klebsiella pneumoniae. |
1. UTI
2. 1-5% of penumonia |
| What is the major virulence factor of Klebsiella penumoniae? |
| capsule |
| Proteus make this enzyme _________ that causes the pH to increase. This favors its growth and makes the symptoms worse. |
| Urease |
| What is the etiologic agent of plague? |
| yersinia pestis |
| What are the important features of the diseases caused by Yersinia pestis? |
Can be Bubonic, Septicemic and Pneumonic
Bubonic = Lympth nodes are infected, usually groins; pain in limbs and get fever
Septicemic = Spreads to liver and lungs
Pneumonic = Infection of lungs, rapid spread, high fatality rate |
| How is Yersinia pestis transmitted? |
Wild rodent---flea----wild rodent Wild rodent---flea----domestic rodent---humans
|
| What is the significant of Y.Pestis being able to grow at high or low temperature? |
| In fleas, below 27 C, the bacteria makes coagulase. This clots the blood and makes fleas feel hungry so they will bite more people. |
| What are the virulence factors for Yersinia pestis? |
response is related to the location.
In fleas = low temp = coagulase = more bites In blood = Antiphagocytic Fraction 1 Ag = high temp
In macrophages = High temp, low Ca2+ = Expression of outer membrane proteins |
| T/F: Penicillin is most effective against Y,pestis. |
| False; but other antibiotics are effective! |
| Gram - curved bacilli = |
| Vibrio |
| What are the variants for Vibrio? |
Vibrio Cholera = associated wi/epidemics Vibrio Vulnficus = associated w/wounds |
| Why is Fla a good place for Vibrio to grow? |
| Multiplies in warm salty water such as the beaches. |
| How is V.Cholerae transmitted and what happens to the ID if you take an antacid? |
Food and Water
High ID50> 10^8, but if neutralize pH then ID50 ~ 10^4. (now more likely to get sick) |
| What are the major virulence factors for V.Cholerae |
1. Motility 2. Attachment (to M cells) 3. Enterotoxin production ( A-B toxin) |
| What does halophilic mean? |
| Salt loving conditions |
| What are the 2 major routes of infections with V. Vulnificus |
Wound infections = cuts exposed to contaminated water, shellfish or crabs swelling to necrosis
Septicemia = Ingestion of contaminated seafood |
| Campylobacter jejuni is another example of a gram - rod, it has a _______ ID50 and causes gastroenteritis. What syndrome occurs with this? |
low
Guillain- Barre Syndrome |
| What are C.Jejuni virulence factors? |
Attachment Toxin
(destroys the tight junction and causes the cells to disperse and die) |
| C.Jejuni usually occurs in the ______________ with the ______________ of H2O. |
Summer time Recreational use |
| _______________ is a common skin inhabitant; infects prosthetic parts inserted into humans like valves, catheters, shunts. |
| Staph Epidermidis |
| Does Staph or Strep like salt? |
| Staph |
| What enterotoxins does Staph have? |
A-E with all similar activities
Are super antigens that increase cytokine, nausea, vomitting, and cause severe watery diarrhea with no fever |
| What kind of cells do B toxins of Staph attack? |
RBCs WBCs Macrophages Fibroblasts Platelets |
| Alpha toxin of Staph may be responsible for _____________ during infection. It can cause necrosis. |
| tissue damage |
| S.Aureus is a ______________ pathogen. |
| Low grade |
| Exfoliative toxins have 2 forms..both are ___________ and break intracellular bridges in the epidermis. Produce ______________. |
Proteases Scalded skin syndrome |
| What types of enzymes does Staph possess? |
Coagulase Hyaluronidase Staphylokinase Lipases Nucleases |
| Coagulase is aka _____________ whereas hyaluronidase is aka _____________. |
Clotting factor spreading factor |
| T/F: Coagulase makes a gel around the bacteria. It insulates it so WBC cant reach the bacteria. |
| True |
| Staph contains _____________ that binds to Fc portion of an Antibody. It causes it to ____________ and takes it out of circulation. Antibodyno longer functions properly. |
Protein A Precipitate |
| ________________ is the main component of connective tissue. |
| Hyaluronic acid |
| Staphylokinase is another example of a ______________ because it dissolves the human clotting components. |
| Spreading factor |
| What are furuncles? |
| Raised rash: infection of hair folicles producing areas of raised, painful ndoules with necrotic tissue underneath |
| What are carbuncles? |
| Fusion of furuncles and invasion of deeper tissue |
| What is TSST? |
Toxic Shock Syndrome
(Staph infection from tampon causes superantigen = shock) |
| Name diseases caused by Chlamydia trachomatis |
1.Chlamydia 2. Trachoma (conjuctivitis) 3. Reiters syndrome 4. PID 5. Lymphogranuloma venerum |
| What are the 2 forms of chlamydiaceae? |
1. Infectious elementary bodies 2. Non-infectious reticulate bodies |
| Chlamydia is an _____________ organism with no ___________ and needs __________ from there host cells. |
Energy dependent cell wall ATP |
| Why was Chlamydia first mistaken as a virus? |
| Because both are intracellular parasites and require energy from there host and both have no cell walls. |
| T/F: Not all Chlamydia is from an STD. |
| True |
| T/F: The most commonly reported STD is Gonorrhea. |
| False; Chlamydia is |
| What are the 3 biological varities of the chlamydia trachomatis? |
1. Trachoma 2. Lymphogranuloma venereum (LGV) 3. mouse pathogen |
| Trachoma deals with eye infections and venereal diseases. It is the leading cause for _____________________ and 75% of women are _______________-. |
Non traumatic blindness Asymptomatic |
| Where do men get infections caused by Chlamydia? |
Urethra prostate gland epididymis |
| What do women get if infected with Chlamydia? |
Cervical infection Inflmmation of the fallopian tubes
can lead to sterility or ectopic pregnancy |
| What is salpingitis? |
| A infection is accomponied by inflammation and necrosis. This can block the egg from the ovaries to enter the uterus. |
| A urogenital infection caused by Chlamydia have ___________ being more asymptomatic. Some usual symptoms include ______________ with a discharge. |
women urethritis |
| What is the most common direct specimen test to detect Chlamydia? |
| Frozen antibody |
| Neisseria are gram - cocci that have ____________ instead of LPS. |
LOS LipoOligosaccharides |
| Neisseria are non motile and _____________. |
| Aerobic |
| T/F: Neisseria meningitidis only affects humans and transmission is by contact. |
| False; it does only affect humans, but trasmission is by aerosols |
| What are the virulence factors for N.Meningitidis? |
1. Capsules = antiphagocytic 2. Endotoxin = LOS 3. IgA proteases 4. Transferrin = steals Fe from host |
| What is Petechiae? |
Small, purplish hemorrhagic spots on the skin that appear in certain severe fevers; they are indicative of great prostration.
(skin infection from N.meningitidis) |
| What are the important characteristics of N. meningitides? |
Colonize in the nasal passage In 7-10 bactercidial Ab is made and bacteria spreads (Carrier state persists for days to months) Mild fever, pharyngitis Septicemia w/fever and shock because of LOS Inflammation of brain and spinal cord |
| Why do some people get the N.Meningitidis disease whereas others become carriers? |
| Individuals with disease were more likely to have a defect in their complement system: C8 was low. This lead to a 5000-10000x increase in sensitivity to disease. |
| What results from a lowered complement component? |
| Phagocytosis is normal but extracellular killing is reduced |
| Penicillin can corss the BBF during inflammation but does not eliminate the carrier state. Which antibiotic does tho? |
| Rifampin or Chloramphenicol |
| N.gonorrhoeae is ______________ to environmental stress. |
Not resistant
Sensitive to sun, heat and cold |
| What type of virulence factors does N.gonorrhoae has and which is the most important? |
1. Pilli= usually attach to urinary tract (MOST IMPORTANT) 2. Opa proteins = mediate binding to cells 3. Tbps and Lbp = Tranferrin/ Lactoferrin 4. LOS = with Lipid A and endotoxin activity |
What are the possible complications of disseminated gonococcal infection |
Baacterimia leading to disseminated gonococcal infection. Infection in the joints can lead to arthritis Newborns can get severe eye infections that can lead to blindness. |
| Men have a _______ chance of being infected, but if they are infected _______will show clinical symptoms. |
1/5 95% |
| What are some complications of Gonorrhea in men? |
| Infection of the prostate and infection with other bacteria |
| How does gonorrhea affect women? |
Most are asymptomatic Bacteria attaches to columnar epithelium cells and some are engulfed and transported into the submucossal area and causes irritation and some clinical symtpoms such as pain with pee, vaginal discharge and ab pain. |
What other antibiotics are used to treat gonorrhea? |
| Quinolones |
| Why is it difficult to develop a vaccine for gonorrhea? |
| because of antigenic variability |
What are the chances of gonorrheal infection after a single exposure for male and female? |
Men = 1/5 Women = 1/2 |
Which diseases discussed in class are zoonotic diseases? And what does zoonotic mean? |
Bacillus Anthracis
Affects domestic and wild animals |
| Bacillis and Clostridium are similar in morphology but Bacillus is _____________while Clostridium is an ____________. |
Facilitated anaerobe Obligate anaerobe |
| What are the common routes of transmission of Bacillus anthracis? |
1. Cutaneous (most common) 2. Inhalation (lethal) |
| What are some characteristics of TB? |
Slender rod shaped Gram + Non spore forming nonmotile Aerobic or faculative anaerobic bacilli Has capsules but are not effective so get ingested in to macrophages but survive due to high lipid content on cell wall (allows survival in harsh conditions)
|
| What is the significance of the cell wall of the TB agent? |
| Has a high lipid content so allows survival of harsh conditions. Makes resistant from drying and from drugs |
What is the mechanism of pathogenesity of TB agent? |
| TB microbe prevents the fusion of the lysosome with the phagosome so it becomes an intracellular pathogen |
| What is a tubercle? |
| An alveolar macrophage with a live bacteria in it |
What are the main clinical manifestation of TB? |
Productive, persistent cough Weight loss fatigue night sweats |
What are the characteristics of TB skin test? What material is used in the test |
Intracutaneous injection. Read it 48-72 hrs later. (hypersensitivity rxn) Results vary. either you have it, had it, or have a vaccine for it.
they inject the mycobacterium. |
| T/F: TB has a long generation time. |
| True |
| What is cell mediated failure? |
| The hard shell breaks down and the tubercle escapes and multipies. The disease is now developed. Occurs once the bacilli are uncontrolled by the immune system. |
| What vaccine is used to prevent TB? |
| BCG = Bacilli Calmete Guerin |
| What are some characteristics of Myco.Leprae? |
Gram + bacilli Obligate intracellular parasite Non toxic Acid fast |
| What is the pathogenesis for Leprosy? |
Destroys schwann cells and axons
Degenerative myelination and axon degeneration |
| T/F: Leprosy can be cured with an antibiotic |
False There is no cure no vaccine |
| How do you treat leprosy? |
Improve their symptoms, but little to none in nerve damage. Multi antibiotic therapy is needed |
