MICROBIOLOGY Flashcards
Who should you never give a drug ending in -azole to? What is albendazole?
PREGNANT WOMEN ALL ARE TERATOGENIC; an anti-helminthic but still teratogenic just like the anti-fungals ending in azole
Which organism is associated with sushi from Japan and rusty-colored sputum? Which organism is associated with diarrhea/vomiting after eating sushi from Japan?
Paragonismus westermani (lung fluke); Anasaki simplex
Which normal flora of the mouth are protective against URTs?
Diphtheroids, Alpha/Gamma strep and Neisseria species
What is another name for Haemophilus aegypticus? What does it cause? What is a more common cause?
Koch-Weeks Bacillus; Pink eye, more commonly adenovirus
Though exanthems are more typical of viral pharyngitis why doesn?t the presence of a rash rule out Strep as the cause?
Because they could have the sandpaper rash of Scarlett Fever
A mother comes in and is worried about her 3 year old child getting pneumococcal pneumonia, how can you prevent this?
With the CONJUGATED vaccine, recall that is the appropriate vaccine for kids under 5 not the polysaccharide
Which virulence factors are most important for H flu to produce pneumonia? How does it produce shock?
CAPSULE is the major virulence factor (polysorbitol phosphate); Endotoxin (LPS) can produce shock in any gram negative bacteremia
Which anaerobes tend to cause pneumonia? What are the 2 major risk factors?
Fusobacterium and Bacteroides? Dental work and loss of consciousness (i.e. aspiration)
What are the 3 types of ALLERGIC aspergillosis?
IgE-mediated asthma, Allergic bronchopulmonary aspergillosis, and Farmer’s lung
What is the gram reaction, hemolysis, and catalase test for Strep pyogenes?
Gram positive cocci in chains, beta hemolytic, catalase negative
What is the major manifestation of streptococcal pyrogenic exotoxins?
Scarlett Fever: sandpaper rash and strawberry tongue, and apparently post-strep glomerulonephritis
Why don?t most foreign students at LECOM have to get a PPD?
Most of them have the BCG which may or may not confer immunity BUT, at any rate, if a person has the BCG then their PPD will be positive so the test is invalid
What are 4 antigens that M protein seems to cross react with?
Cardiac myosin, Sarcolemmal membrane protein, Synovium, and Articular cartilage
Where is Klebsiella naturally found? How is the sputum different from that of a S. pneumo pneumonia?
It is normal flora of the mouth; It is a thicker sputum and it is a darker red. This is because of Kleb’s very thick capsule
What is the “buzzword” for noninvasive pulmonary aspergillosis? Predisposing factor?
Fungal ball/Aspergilloma, basically they are infected with Aspergillus that colonize a pre-existing cavity from TB or S. aureus cavitations etc.
What type of agent are the most common cause of bronchitis?
Viruses
What are the 4 virulence factors of Streptococcus pneumoniae and their functions?
Capsule to evade phagocytosis, IgA protease to evade mucosal immunity, Adhesins to bind to cells, and pneumolysin to lyse the cells
What is the causal agent of “Valley Fever”?
Coccidiodes immitis
Which kind of patients are you most likely to see black pus coming from the mouth and eyes? Organism?
Diabetic ketoacidotics, Mucor
Which virulence factor of B. pertussis essentially causes a “diarrhea in the lungs”?
Pertussis toxin which ADP-ribosylates Galph(i), this inhibits the inhibitor of adenylate cyclase, allowing for more cAMP to be produced. This is done along with adenylate cyclase toxin which also increases cAMP? Both = more secretion
Regarding the fastidious nature of H. influenzae, what is factor X? Which agar provides this?
Factor X = heme; chocolate agar
What are two stains that can be used for TB? What agar does it grow on?
Can use an acid fast stain and an auramine rhodamine stain; Lowenstein Jensen agar (6-8 weeks to grow)
What are the complications of Nocardiosis?
Abscesses in the brain and kidney
What is the gram stain and shape for pertussis? What agar does it grow on?
Gram negative coccobacillus; Regan Lowe agar
What are the normal flora of the LRT?
There are none, it should be sterile
Which atypical pneumonia bacteria MIGHT you see on gram stain? What are 4 bacterial causes of atypical pneumonia?
Legionella pneumophila MAY be seen. FOUR: Legionella, Coxiella burnetii, Chlamydophila (pneumoniae, psitacii), and Mycoplasma
What is different about Aspergillus and Candida?
Although both are ubiquitous, Aspergillus is a TRUE MOLD and Candida is a true YEAST
Is B. pertussis very contagious? What is the transmission?
YES over 90% not immune who are exposed develop pertussis? it is person-to-person transmission
How do you diagnose mucor? Tx?
KOH prep and will see ASEPTATE right-angle branching hyphae; give AMPHOTERICIN B because the -azoles don’t work well!
Which bug is the number 1 AIDS-associated infection? When/what do you prophylax with?
Pneumocystis jiroveci; When CD4
Why is Haemophilus influenza fastidious? What is its gram stain?
Because it ONLY GROWS ON CHOCOLATE AGAR as it requires Factors X and V? Gram negative coccobacillus
What is the agar for Diphtheria? What test can be used to check for Diphtheria?
Loeffler’s or Tellurite selective media (Tinsdale agar)? Modified ELEK test
Why are there increased PMN’s in pneumococcal pneumonia?
S. pneumo is the cause of pneumococcal pneumonia and although neutrophils are useless against its CAPSULE they are nonetheless present because, since Spneumo needs to be OPSONIZED the IgG opsonins will form complement-based anaphylatoxins which ATTRACT PMNs. Also, peptidoglycan and techoic acids are able to activate complement = more anaphylatoxins = more PMNs
Why do we not have P. westermani in the U.S.? What does its egg look like? Sputum?
Because, being a fluke, its intermediate host is a snail and this particular snail does not live in the U.S.; The egg is coffee-bean shaped and OPERCULATED; the sputum is coffee ground or rusty
Why shouldn?t you completely lose your shit if you have a positive PPD?
Because PPD indicates EXPOSURE, you may or may not actually have TB
What does bacitracin help to differentiate? What about optochin?
Bacitracin is to differentiate beta hemolytic strep with pyogenes sensitive; Optochin for alpha hemolytics with S. pneumo sensitive
Which patients are most likely to die from Aspergillosis?
A NEUTROPENIC patient that gets an aspergillus fungemia = 90% mortality
What are the most common extrapulmonary Sx of P. westermani?
They resemble meningoencephalitis
Name the 5 potential bioterrorism threat bugs that cause pneumonia:
Bacillus anthracis, Yersenia pestis, Coxiella burnetii, Francisella tularemia, and Brucellosis
How can you prevent Haemophilus influenza epiglottis? Can they still get H. influenza otitis media?
With aCONJUGATED vaccine against the capsule, since these have a capsule. Yes they can still get otitis media because those types have no capsule and vaccination is useless
What are two good ways to diagnose yeast infections in general (lab)? What are 3 signs of viral infection of cells?
KOH prep because it dissolves our cells and bacteria; Sabourad Dextrose agar to grow fungi; Koilocytes (HPV), Inclusions (Negri, Cowdry, Owl’s eye, etc), and syncytia
What is the DOC for a person with hemoptysis coming back from the world’s largest sushi-sampling event in Tokyo?
PRAZIQUANTEL, this is an infection with Paragonismus westermani
What is the major antibiotic resistant strain of K. pneumo?
Carbapenam resistant, produces carbapenamase
What is the problem with the gold standard for definitive Dx of TB? Is TB aerobic or anaerobic?
The gold standard is to culture it on Lowenstein-Jensen Agar but that can take several weeks? Aerobes
Which virulence factors of B. pertussis bind to ciliated epithelium (2)? Which is responsible for the fever?
Ciliated epithelium binding: filamentous hemagluttinin and pertactin? Fever = tracheal cytotoxin because it stimulates IL-1
Which dimorphs can be found in the eastern to central states? Which is found in Arizona?
Ohio river valley: Histoplasmosis and Blastomycosis; Arizona–Coccidiodes
Based on Hx how would you know which dimorph was causing pneumonia in someone from Ohio?
If in caves or near birds: Histoplasma capsulatum; If near decaying wood etc., then Blastomyces dermatidis
What makes a strain of Diphtheria toxic? How does the toxin function?
They must be LYSOGENIZED with a beta-prophage that has the TOX gene. It is an AB toxin. B binds to the heparin-binding epidermal growth factor receptor on heart and nerves and the A toxin functions in ADP-ribosylation of EF2–only one molecule of toxin to kill whole cell!
What are 3 endemic areas for TB?
Southeast Asia, Eastern Europe and Sub-Saharan Africa
Who has right-angle branching hyphae?
MUCOR (fungi in the order mucorales)
Which two bugs are PYR positive? What does PYR stand for?
Enterococci and Strep pyogenes?. L-pyrrolidonylaryltransferase
What immune response is activated with conjugate vaccines?
T-cell response (this is kind of dumb)
Regarding the fastidious nature of H. influenzae, what is factor V? Which agar provides this?
Factor V = NAD; chocolate agar
What are the big 3 agents that cause otitis media?
Streptococcus pneumoniae, Haemophilus influenza (NON TYPEABLE), and Moraxella catarrhalis
What is the typical presentation of a kid with epiglottitis?
They will have very sore throat and actually lean forward and drool because it less painful and they don?t want to swallow their saliva; inspiratory stridor and expiratory rhonchi with a cherry red epiglottis
In what way is the environmental reservoir of Legionella not all that different from where it stays in us?
It lives in ameobae in the environment and in alveolar macrophages in us, MO are really not all that different from amoebae!
How would you differentiate Proteus (vulgaris/mirabilis) from Shigella?
Both are lactose non-fermenters and are H2S positive, Proteus produces UREASE and has swarming motility
Why isn’t vaccination for Haemophilus influenza useful for H. influenza acute otitis media?
Because the antigen for the vaccine is the CAPSULE and the non-typeable forms that cause acute otitis media are NON ENCAPSULATED
Where is diphtheria common? How is it spread?
3rd world countries, respiratory droplets
What is MDR-TB resistant to? What is XDR-TB resistant to? What is the purpose of DOTS?
MDR-TB resistant to isoniazid and rifampin; XDR-TB resistant to isoniazid, rifampin and AT LEAST ONE second line drug? DOTS = Directly Observed Treatment Short-course is where someone actually watches you take the drug to deal with compliance issues.
Name 2 pneumonia causing bacteria that have IgA protease. Name 2 others that classically have IgA protease.
Strep pneumo and Haemophilus influenza. The Neisseria species (meningitidis and gonorrhea both have it as well)
What fungus is typically transmitted with a thorn prick in gardeners?
Sporothrix a dimorph (can have both Shapes)
What findings are more likely from the non-typeable Haemophilus influenza strains that cause acute otitis media?
More likely to find conjunctivitis than otitis media
What do kids with otitis media do to their ears? Why?
They pull on them, because the Eustachian tubes in kids are horizontal so this can pull them more vertically and improve drainage
A young man recently immigrated from Russia and has exudative pharyngitis, a bullneck, EKG changes and his uvula deviates to the left. He is clearly missing a vaccine with what formulation?
TOXOID vaccine (DTaP and Tdap)
What are the typical four drugs used to Tx TB? What is MDR-TB? XDR-TB?
DRUGS: Isoniazid, Rifampin, Ethambutol, and Pyrazinamide; Multi-drug resistant TB and Extreme drug resistant TB (Andrew Speaker)
How would you diagnose Aspergillus pulmonary infection?
Microscopy of acute-angle branching hyphae, and if non-invasive type do chest X-ray for fungal ball
Which bug is likely to cause a frothy bloody sputum? What is the Tx?
Yersinia pestis (pneumonic plague)? Streptomycin, tetracycline, and chloramphenicol
Who is at the biggest risk for invasive pulmonary Aspergillosis?
The neutropenic patients (BM transplant, AIDS etc)
What are Bordatella parapertussis and Bordatella bronchiseptica?
Parapertussis is a milder whooping cough, NO PERTUSSIS TOXIN and bronchiseptica is in animals (sniffles in rabbits, Kennel cough)
What is the gram stain for the bug that infects the lungs infects young adults and is tested for with cold aggluttinins?
NONE this is mycoplasma which lacks a cell wall
What are cold agglutinins used for in respiratory diagnosis? How does it work and why is preferred to culturing the bug in question?
Mycoplasma pneumoniae; They are IgM antibodies against mycoplasma that cross react with RBC’s? Preferred to culture because it would take 6-8 WEEKS