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
What are the top 3 bugs for bronchitis? Why is that so familiar?
Streptococcus pneumoniae, Haemophilus influenze, and Moraxella catarrhalis–THEY ARE ALSO THE TOP 3 FOR ACUTE OTITIS MEDIA
What does the mold of Blastomyces dermatidis look like? The yeast?
Mold: hyphae w/ nondescript conidia; Yeast: Broad-based budding yeast
What are two major ways to differentiate croup from epiglottitis? What is infected in croup?
Croup (tracheitis/laryngitis from parainfluenza virus) has a SEAL BARK COUGH; also, do they have the HiB vaccine? That would lead you down the path of croup.
Which type of hypersenstivity reactions can dermatologic strep infections cause?
Skin strep infections can cause Type III (Glomerulonephritis) but they cant cause Type II cytotoxic–no rheumatic fever
Describe the pathogenesis of Coccidiodes immitis:
It is a dimorph and so the MOLD will be inhaled into the lungs (in the desert southwest) and then many spherules will form with endospores (baby yeast) inside. The spherules will rupture and each endospore forms a new spherule with more yeast. The process continues and there is essentially a space-occupying lesion in the lung
What are some major risk factors for Legionella pneumophila? What are two ways you can detect it?
Elderly, COPD, and smoking; Buffered Charcoal Yeast Extract agar or DETECT THE ANTIGEN IN URINE
MORAXELLA CATARRHALIS: What is the gram reaction? Where does it come from? What antibiotics can’t you give?
Gram negative diplococci, NORMAL FLORA, most have beta lactamase so NO PENICILLIN
What are the 3 clinical types of TB infection?
There is primary TB (initial lesion is the tubercle). Secondary TB is when there is reactivation of the primary TB and then miliary TB is when it spreads to distal sites
Which agent was originally known as the Taiwan Acute Respiratory Agent? How likely are they to die? Tx?
Chlamydophila pneumoniae, very unlikely and prob won’t even seek Tx. If they do, it is azithromycin and clarithromycin. Doxycycline may also be used.
What is the most common cause of acute otitis media? What is the most common cause of pierced ear infections?
Streptococcus pneumoniae; Pseudomonas aeruginosa
How do you treat an anaerobic pneumonia?
METRONIDAZOLE for 2-4 months
Which bugs cause acute bronchitis (1)? Chronic bronchitis (3)?
Acute = Mycoplasma pneumoniae; Chronic = Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis
What is acute diffuse otitis externa most commonly known as?
Swimmers ear, it is similar to a folliculitis
Why can TB survive in a dry environment?
Because mycolic acid prevents desiccation
What are the top 3 bugs for acute otitis media again?
Streptococcus pneumoniae, Haemophilus influenza (NON TYPEABLE), and Moraxella catarrhalis
In general, why do AIDS patients get fungal infections?
Normally, fungi are nicely controlled by CD8 cells (CMI) but these, of course, are controlled by TH1 cells (a type of CD4) since AIDS lose their CD4 cells there is no way to activate CD8 and so they are useless = fungal proliferation
How is tuberculosis similar to Chlamydophila in terms of where it goes in the lungs? What is different?
Both go to alveolar macrophages but TB is FACULTATIVE intracellular whereas Chlamydophila is OBLIGATE intracellular and also has the ELEMENTARY and RETICULATE bodies
What bug is a weakly gram positive acid fast aerobic rod?
Mycobacterium avium complex (MAC)
Which bug is a major pneumonia threat in cystic fibrosis patients? Gram stain and shape? Color?
Pseudomonas aeruginosa, Gram negative rod, green (pyocyanin + pyoverdin)
Who has acute angled branching hyphae?
Aspergillus
What are the gram stains of the 3 most common causes of acute otitis media?
Gram positive diplococci (S pneumo); Gram negative diplococci (Moraxella); and Gram negative coccobacillus (H flu)
What is the main virulence factor of TB? What does it do? What causes tissue necrosis in TB?
CORD FACTOR but the function is unknown. TB lacking cord factor are less virulent? TNF alpha from our immune system causes tissue necrosis
What do you give a person who has had POTENTIAL exposure to TB? How is this drug metabolized and what are the implications for pharmacogenetic population distributions?
ISONIAZID, it is metabolized by N-acetyltransferase in the liver, thus it is possible to have a bimodal curve for serum levels due to genetic polymorphisms with slow and fast acetylators (U-World)
What does mycolic acid do for Mycobacterium tuberculosis?
Resistance to detergents and COMMON antibiotics and protection from dessication
Which organism is responsible for black mold on wet wood and paper? What toxin allows it to cause its Sx? What are the Sx?
Stachybotrys chartarum; mycotoxin–asthma-like Sx
Which organism is notable for being able to form a empyema? What is empyema?
Staphylococcus aureus; empyema (or pyothorax) is a pyogenic (pus) infection of the pleural cavity
What should ppl potentially exposed to pertussis get? What is the DOC for individuals with pertussis?
Erythromycin; 14 d of erythromycin
Why is the Tx for MAC different than TB?
MAC is resistant to the typical TB medications and so you replace isoniazid and rifampin with azithromycin and clarithromycin, they still get ethambutol and pyrazinamide
Briefly explain the function of the 5 B. pertussis virulence factors:
Pertactin and Filamentous hemagluttinin bind ciliated epithelial cells, Adenylate cyclase toxin and Pertussis toxin (ADP ribosylation of Gi) stimulate excess secretion, and tracheal cytotoxin kills the cells so that the secretions can’t get out and causes the characteristic whooping cough and stimulates IL-1 leading to fever
What is the difference in seasonality and onset of viral and streptococcal sore throat?
Viral is usually all year and there is a prodrome wheras Group A strep are usually winter and early spring and ABRUPT onset
If someone’s rapid strep test is positive, do you need an ASO titer?
NO and you wouldn?t get one anyway to confirm streptococcal pharyngitis. ASO titers are useful to tell you if there WAS an infection (as in, weeks ago!)
What are the major risk factors for H. influenzae pneumonia?
COPD and Smoking
How do you treat the most common cause of pneumonia?
Ampicillin and if allergic then macrolide (erythromycin and azithromycin); Strep pneumo
What are the major predisposing factors for Allergic Bronchopulmonary Aspergillosis? What kind of hypersensitivity is this?
Asthma and Cystic Fibrosis (also S. aureus and P. aeruginosa); this starts out as a Type I but progresses to Type III and eventually type IV
What are 4 causative agents of epiglottitis?
Haemophilus influenzae, Staphylococcus aureus, Streptococcus pneumoniae, and Strep pyogenes
How is the incidence of different types of URT infectiosn different in adults than kids?
Adults are more likely to get sinusitis while kids are more likely to get pharyngitis and otitis media
Which dimorph has a spherule? What is a spherule?
Coccidiodes immitis, a spherule is is a structure that contains a bunch of baby yeast, basically
Can a Group A strep strain that causes necrotizing fasciitis cause rheumatic fever as well?
NO, pyodermal strains are not associated with M protein subtypes that cause rheumatic fever
What does Pseudomonas cause on the external ear?
Malignant/Invasive Otitis Externa
Which vaccines for strep pneumo are appropriate for what age groups?
Healthy adults get the polysaccharide vaccine and kids + IC patients get the conjugate vaccine
Which lesion of TB is likely to undergo dystrophic calcification?
The Gohn complex, so these are not really cheese-like as the tubercles are. They are hard and they are in pulmonary lymph nodes as well as lung parenchyma. Because they are calcified, that is why they are easy to visualize on CXR.
What is infectious form of the atypical pneumonia carried by birds? Tx?
The ELEMENTARY BODY of C. psittaci. Clarithromycin or Erythromycin; Doxycyline may be used
What is the DOC for 1) Allergic Aspergillosis 2) Non-invasive Aspergillosis 3) Invasive Aspergillosis
1) Allergic Aspergillosis = oral corticosteroids 2) Non-invasive = Surgical excision of fungal ball 3) Invasive = VORICONAZOLE, this actually replaces amphotericin B
How would you diagnose B. dermatitidis in the lab? What is the Tx for immunocompromised and immunocompetent patients?
Look for broad-based budding yeast on microscopy? IC = amphotericin; healthy = itraconazole
A young man comes back from central america with pulmonary distress, microscopy reveals multiple budding yeast, what’s the deal?
Paracoccidiodes brasiliensis; similar to coccidiodes, the yeast has A “PILOT’S WHEEL” appearance
What kind of capsule does Group A strep have? Is it the antiphagocytic virulence factor?
Hyaluronic Acid capsule, no the M protein is
Name the 5 virulence factors of Bordatella pertussis:
Filamentous hemagluttinin, Pertactin, Pertussis Toxin, Adenylate Cyclase Toxin, and Tracheal Cytotoxin
Which virus may cause an exudative pharyngitis?
EBV
What are the 3 different categories of pulmonary disease for Aspergillus?
Allergic (Hayfever, Allergic Bronchopulmonary Aspergillosis, & Farmer’s lung), noninvasive, and invasive
What other 4 things should be on the differential for epiglottitis?
Croup with parainfluenza virus; Angioedema as an autoimmune problem; inhalation of foreing object bc of the stridor; and retropharyngeal or peritonsillar abscess
How does one get exposed to Mycobacterium avium? Who are you concerned about it with? What do you give these ppl?
It is UBIQUITOUS, present in soil etc. Concerned in AIDS pts with CD4
Why would a person treated for Diphtheria need a vaccine?
Because the treatment is an antitoxin. Since all the toxin (antigen) will be bound up in immune complexes it will not stimulate a memory response. Thus, after successful clearance of the toxin, the pt should be vaccinated with the TOXOID vaccine
What is the Tx of Nocardiosis? What does it grow on?
BACTRIM (trimethoprim sulfamethoxazole) and Linezolid, BLOOD AND CHOCOLATE AGAR
How is Hay fever different from Allergic Bronchopulmonary Aspergillosis? How is Hayfever different from Farmer’s lung?
Hayfever is a Type I hypersensitivity (IgE-mediated) response to inhaled aspergillus spores and ABPA is an actual COLONIZATION of the bronchial tree with Aspergillus in ppl with asthma; Hayfever differs from Farmer’s lung in that there is no IgE in Farmer’s lung, in fact, they have IgG
If you took a skin scraping of Scarlett fever rash, what hemolysis pattern would you get on blood agar?
NOTHING AT ALL, the rash is TOXIN-MEDIATED? NO BUGS!
Which drugs are monoclonal antibodies to the molecule that causes night sweats and weight loss in TB infections?
Etanercept and Infliximab–against TNF-alpha
What are 3 major ways bacteria get into the lungs?
1) Aspiration of GI contents 2) Inhalation of respiratory aerosols and 3) Hematogenous spread, usually bad bc implies distant infection
Explain Farmer’s lung:
They form IgG antibodies against the actinomycetes (aspergillus) and whenever they are exposed they get a Type III/IV hypersensitivity, it will go away if they get away from the moldy hay, but it will come back anytime they are exposed.
Differentiate cryptosporidium parvum and cryptococcus neoformans:
Cryptosporidium parvum is an AIDS-associated protozoan that is a GI infection leading to watery diarrhea, and Cryptococcus neoformans is a mold associated with AIDS meningitis and pigeon poop
What general type of bug grows on MacConkey agar? What happens to the agar in fermenters and non-fermenters?
Gram Negative Rod? Normally the agar is pink. If it ferments lactose to acid it turns purple, if it does NOT ferment, it turns yellow
What is the function of pertactin? Which B. pertussis virulence factor is responsible for the characteristic cough and why?
Pertactin binds ciliated epithelial cells? Tracheal cytotoxin because it kills of the tracheal mucociliary escalator; thus, they try and try to cough up their excess secretions but can’t b/c no cilia then they inhale paroxysmally leading to the characteristic “whoop”
What are the 3 virulence factors of Haemophilus influenza B?
1 = polysorbitol phosphate capsule; IgA protease, and LPS
What is the gram stain/shape of Coxiella burnetii? Where does it stay in our bodies?
Gram negative coccobacillus, it is obligate intracellular
Which 2 vaccines are available for pertussis? Which is recommended and why?
Whole killed vaccine but can result in neurologic side effects; Acellular vaccine is recommeded
What is “Some Killers Have Nice Capsules”?
Steptococcus pneumonia, Klebsiella, Haemophilus, Neiserria MENINGITIDIS, and Cryptococcus neoformans = enveloped organisms
Which bug may cause pneumonia from ingestion of unpasteurized milk?
Coxiella burnetti (Q fever)
How are the dimorphic fungi usually acquired? Which form is infectious again?
Inhalation, rarely person-to-person; The mold is the infectious form
Who is most susceptible to infection with Stachybotrys chartarum? How do you prevent?
INFANTS, clean with BLEACH
How is TB transmitted? What is the incubation period?
Respiratory droplets, several weeks
What is the gram stain of the Chlamydophila pneumonias? How do you treat them?
TECHNICALLY gram negative but you can’t actually see anything bc they are obligate intracellular; both treated with the macrolides azithromycin and erythromycin but doxycycline can also be used
How do you get Histoplasma capsulatum and where? How is the method of infection different from the other dimorphs?
Caves in Ohio; This is an INTRACELLULAR INFECTION. Coccidiodes had the spherule and Blastomyces had the broad-based budding yeast, neither were intracellular
What is the gram stain and shape of Yersinia pestis? Where will you find it? What is the reservoir?
Gram negative coccobacillus with bipolar staining; Desert southwest in prarie dogs
How is the MOA of the fungal -azoles (Fluconazole and Ketoconazole) different from that of Amphotericin B?
Amphotericin B TARGETS ERGOSTEROL and Keto/Fluconazole targets ERGOSTEROL SYNTHESIS, and have less side effects
Immunity to a given strain of Group A strep involves antibodies against what?
M protein, NOT antibodies against streptolysin O that is only useful for testing
Which fungi are dimorphs? What is the infectious form?
Coccidiodes, Histoplasma capsulatum, Blastomyces, and Sporothrix? The mold (in the cold)
Why does a patient with latent TB that gets AIDS have reactivation of TB?
Because TH1 cells essentially control granuloma formation and can keep TB dormant but when they get AIDS and lose their TH cells in general, they can’t keep up and it just busts right on out of those granulomas
S Pneumo: Gram stain? Hemolysis? Optochin? Bile solubility? Capsule type?
Gram postivie diplococci, alpha hemolytic, optochin sensitive, yes bile solubility, polysaccharide capsule
In what way is an anaerobic pneumonia potentially similar to a S. aureus one?
Both can potentially lead to EMPYEMA (PYOTHORAX)
What are 2 mechanisms of resistance to antibiotics in P. aeruginosa?
Mutated porin proteins and the production of beta lactamase
A student from Sub-Saharan Africa tells you he does not need a tuberculin skin test because he received a vaccine with this formulation:
Live-attenuated vaccine of Mycobacterium bovis (BCG)
What is a unique Sx of Mycoplasma as an atypical pneumonia? What age group does this tend to occur in?
Excessive sweating (TNF-alpha); Usually college age as opposed to very young/very old
What is the most common type of nosocomial infection? What is the most common cause of death in nosocomial infection?
Most common = UTI but most common cause of death = pneumonia
Compare the features of Nocardia to Mycobacterium avium complex:
MAC is a weakly gram postive acid fast rod that lives in soil; Nocardia is a weakly acid fast gram positive BRANCHING FILAMENTOUS bug that is ALSO found in soil
What is the gram reaction of Bordatella pertussis?
Gram negative coccobacillus
What is unique about the treatment of the organism that infects AIDS patients, is intra-alveolar, and looks like dented helmets on Giemsa Stain?
This is pneumocystis jiroveci; it is a FUNGUS but it is treated with antibiotics (TMP-SMX)
What are the culture media, gram stain, fermentation pattern for Pseudomonas?
CULTURE: Blood agar, chocolate agar, MacConkey agar GRAM STAIN: Gram negative rod FERMENTATION: doesn?t ferment!
What gives TB a characteristic serpentine arrangement?
CORD FACTOR, a virulence factor with an unknown mechanism
What is the gram stain and shape for streptococcus pneumoniae? Hemolysis?
Gram positive enveloped diplococci; alpha hemolytic
What are the 4 signs of nephritic syndrome in post-strep glomerulonephritis?
HTN, coca-colured hematuria, mild proteinuria with periorbital edema
What is the treatment of Klebsiella pneumoniae pneumonia?
Gentamicin (aminoglycoside) and ciprofloxacin (Fluoroquinolone)
This is the rat lungworm (nematode):
Angiostrongylus cantonensis
Both TB and Paragonismus infections can have hemoptysis and night sweats etc. How would you differntiate based on a sputum sample?
TB would not show anything until you did an acid fast or auramin rhodamine stain, whereas P. westermani should have coffee bean like eggs w/o any stain
How is a tubercle different from a Gohn complex?
A tubercle is the initial lesion– a caseating granuloma. The Gohn complex occurs when the bug is no longer just in the lung parenchyma but also in pulmonary lymph nodes
Why do ppl with TB have weight loss and night sweats? What is the cough like?
Because that is what TNF alpha causes, the cough is productive and may be bloody
What is the gram stain and shape of Francisella tularemia? Agar?
Gram negative coccobacillus, Buffered charcoal yeast extract OR Cysteine glucose blood agar
Splenectomy is a major risk factor for pneumonia with this bug. What vaccine should they get?
Strep pneumo; Capsular vaccine
What gives Pseudomonas its green color?
Pyocyanin (blue)and Pyoverdin (yellow)
What is the sputum characteristic of Staph aureus pneumonia?
Salmon pink
Which two bugs can grow on buffered charcoal yeast extract agar?
Legionella pneumophila and Francisella tularemia
What was the original name for Pneumocystis jiroveci? How does it infect?
Pneumocystis carinii; it binds to receptors on ALVEOLAR MACROPHAGES
What is rhinocerebral zygomycosis?
Infection with mucor that infects paranasal sinuses, orbit, and may spread to CNS
How can you differentiate a Coccidiomycosis pneumonia from the other two dimorphic fungi, clinically?
Coccidiodes will have ERYTHEMA NODOSUM which are violaceous spots on the legs usually
What is the gram stain and shape of B. anthracis? What is unique about its capsule? What is the Tx?
LARGE gram positive boxcar rod. The capsule is protein (polyglutamate) rather than polysaccharide? Tx of choice is penicillin but can use ciprofloxacin as well
T/F the M protein is involved in post-streptococcal glomerulonephritis:
FALSE it is either SPE B or NAPlr–Nephritis associated plasmin receptor
What are 3 clinical findings with Diphtheria infection?
1) The grey pseudomembrane with bullneck lymphadenopathy 2) CN IX and X defects since the toxin affects nerves and 3) EKG changes from the myocarditis
Which dimorph lives in alveolar macrophages?
Histoplasma capsulatum
What are the major risk factors for a currant jelly sputum pneumonia?
This is Kleb; Major risk factors are ALCOHOLICS and HOSPITALIZED/VENTILATOR
Why is mortality higher in a Kleb pneumonia than one from S. pneumo or mycoplasma?
Kleb causes NECROSIS of the lung tissue and is therefore more likely to go septic (LPS)
