Test 2 Week 1 Flashcards
When is exposure made on a posterior-anterior view chest x ray?
full inspiration
By which route is mycoplasma pneumoniae spread by?
respiratory route
Nearly ALL anaerobes are resistant to which antibiotic class?
aminoglycosides
What’s responsible for the pathogenesis of EBV mononucleosis?
expansion of atypical CD8+ T cells (Downey cells)
What’s the endemic location for histoplasmosis?
Mississippi and Ohio river valleys
Morphology of Moraxella catarrhalis:
gram negative diploccoci
What’s the MOA of zanamivir and oseltamivir?
they are neuraminidase inhibitors with activity against types A and B
What’s the main use of ultrasound in the chest?
detection and characterization of pleural effusions
Morphology of Pneumocystis jiroveci:
•NOT yeast-like, but has unusual single cell forms, uninucleate sporocysts, or cysts containing up to 8 intracyst bodies.
By which route is Chlamydia psittaci spread by?
transmitted by inhalation
What’s the mechanism of action of Amphotericin B?
binds ergosterol in cell wall of fungi and induces oxygen free radicals to form pores in the membrane
Common causes of pneumonia in adults 18-40:
from first aid: -mycoplasma -chlamydia pneumoniae -strep. pneumoniae
morphology of actinomyces:
gram positive bacilli
What are the important characteristics of staph. aureus? (5 things)
-gram positive -group in grape-like clusters -catalase positive -resistant to drying -very heat resistant
What will the monospot test result be in CMV mononucleosis?
negative monospot test
an intestinal flora that causes lobar pneumonia in alcoholics and diabetics when aspirated
Klebsiella pneumonia
What are some side effects of amphotericin B?
- fever/chills
- hypotension
- nephrotoxicity
- arrhythmias
What’s the MOA of amantadine and rimantadine?
block M2 ion channel function, uncoating, and endosomal entry of influenza A
-but they are ineffective against types B and C
A solitary pulmonary nodule is described as a _____.
focal opacity < 3cm
____ is a unique feature of influenza A
antigenic shift
What’s the endemic location for blastomycosis?
states east of mississippi river and central america and around the Great Lakes
Common causes of pneumonia in children (1 month-18 yrs):
from first aid: -respiratory syncytial virus (RSV) -mycoplasma pneumoniae -chlamydia trachomatis -chlamydia pneumoniae - strep. pneumoniae
How does scarlet fever present?
scarlet rash with sandpaper-like texture and a strawberry tongue
How can chronic Q fever present?
most often presents as endocarditis
What is the most frequently isolated bacteria from infections caused by anaerobes?
bacteroides fragilis
What organism often causes pneumonia in immunocompromised patients?
Pneumocystis jiroveci (asso. w/ AIDS
What method is used to diagnose Legionella pneumophila infection?
antigen test
Most common cause of interstitial (atypical) pneumonia?
mycoplasma pneumoniae
Morphology of Zygomycetes (e.g. Rhizopus, Mucor, Absidia) :
•Typically, they grow as broad, ribbon-like hyphae that are aseptate or sparsely septate and right-angle branching in no pattern.
most common cause of of nosocomial infection?
staph aureus
Corynebacterium diphtheria Characteristics (4 things):
1) gram positive 2) slender rod (but highly pleomorphic) 3) contain metachromatic granules 4) normally found in the mouth (these cells just don’t have a lysogenic bacteriophage)
adenovirus characteristics:
- nonenveloped
- icosahedral symmetry
- linear dsDNA
a child with Croup will show what on radiology imaging?
subglottic narrowing of trachea (steeple sign)
What’s the mechanism of action of Azoles?
inhibit fungal ergosterol synthesis
Mycoplasma pneumoniae is non-invasive. How does it adhere to tissue?
P1 terminal attachment factor
What will the monospot test result be for EBV mononucleosis?
+ monospot test
Morphology of Aspergillus species:
Grow as septate hyphae that are branched at 45 degree angles and form distinct conidiophore structures that do not appear in tissues, but may form in cavities.
What’s the major virulence factor for Streptococcus pneumoniae ?
it’s capsule; it has no virulence without it
What’s the typical treatment for TB?
•Isoniazid (INH) + rifampin + 2 others for 6-9 months
What are the paramyxoviruses we discussed?
–Parainfluenza (HPIV)
–Respiratory syncytial virus (RSV)
–Metapneumovirus (hMPV)
Which bug is responsible for most person to person pneumonia transmission?
strep. pneumoniae
What’s the endemic location for coccidiomycosis?
southwestern US, California
in regards to influenza virus, describe antigenic shift.
reassortment of HA and/or NA gene segments between different subtypes
-causes pandemics
•HA= hemagglutinin and NA=neuraminidase
Paramyxovirus family characteristics:
- enveloped
- helical capsid
- negative sense ssRNA
What’s the best test available to make a histoplasmosis diagnosis?
DNA probe for Histoplasma rRNA
By which route is Legionella pneumophila spread?
aerosol transmission from water supplies
What’s the most common secondary infection in AIDS patients in the U.S.?
Pneumocystis pneumonia (PCP)
most common cause of bronchiolitis in infants
respiratory syncytial virus
What are some effective treatments for opportunistic anaerobes?
- Metronidizole for obligate anaerobes
- Imipenem
- combo of beta lactam antibiotics + beta lactamase inhibitors
How can you identify Coccidioides immitis morphologically?
arthroconidia and spherules
By which route is chlamydia pneumoniae spread by?
respiratory route
barking “seal like” cough=
croup
most commonly caused by human parainfluenza virus (HPIV)
Bronchopneumonia is characterized by:
scattered patchy consolidation centered around bronchioles; often multifocal and bilateral
What gives Pseudomonas aeruginosa it’s blue coloration and grape juice smell?
pyocyanin
Common causes of pneumonia in elderly (>65):
from first aid: -strep. pneumoniae -haemophilus influenzae -anaerobes -influenze virus -gram negative rods
In regards to influenza virus, describe antigenic drift
single point mutations in HA or NA, producing new strains within a subtype
-can result in epidemics
•HA=hemagglutinin and NA=neuraminidase
On coxiella burnetii serology, Phase II IgM and IgG would suggest ___ disease.
acute
What are the most common bacterial causes of lobar pneumonia?
streptococcus pneumoniae (95%) and Klebsiella
Morphology of Mycobacterium tuberculosis:
acid-fast bacilli (don’t stain well with gram stain)
What’s the treatment for Coxiella burnetii infection?
–Doxycycline for acute disease –Chronic disease must be treated with doxycycline and hydroxychloriquine for up to 2 yrs. –If endocarditis is present, it does require surgical intervention.
Treatment for Cryptococcus neoformans?
amphoteracin B
On coxiella burnetii serology, Phase I antigens would suggest ___ disease.
chronic
Legionella pneumophila is difficult to grow in the lab. What all does it require for growth?
cysteine, Fe2+, and charcoal yeast extract agar
gram + cocci; form rods
streptococcus pyogenes (group A strep)
How is TB spread?
inhalation
Describe the vaccine for Haemophilus influenzae (Hib vaccine).
contains type b capsular polysaccharide conjugated to diptheria toxoid
Of the fungi we discussed, which is a CDC select agent (possible bioterrorist agent)?
•Coccidio species
What’s the Rx treatment of RSV bronchiolitis
ribavirin
-only for high risk infants (congenital heart defects, prematurity
Describe morphology of Legionella pneumophila?
gram negative, aerobic rods
how do Nocardia species survive intracellulary?
by preventing phagosome-lysosome fusion, and catalase and superoxide dismustase (SOD)
What is used to treat histoplasmosis?
- amphotericin B
- itraconazole
- fluconazole
Morphology of Fusobacterium:
Recognized morphologically in Gram stains by presence of long, thin rods with pointed ends.
What sequelae can follow streptococcus pyogenes infection?
-rheumatic fever -glomerulonephritis -scarlet fever
How can acute Q fever present?
can present as pneumonia or hepatitis
By which route is Coxiella burnetii spread?
spores inhaled as aerosols from cattle/sheep amniotic fluid (from first aid)
How will an acute PE appear on CT?
clot sitting in CENTER of pulmonary artery, blocking further blood flow
highly infectious and causes human Q fever
Coxiella burnetii
Common causes of pneumonia in adults 40-65:
from first aid: -strep. pneumoniae -haemophilus influenzae -anaerobes -viruses -mycoplasma pneumoniae
What type of hemolysis is strep. pneumoniae characterized by?
alpha hemolysis
What method is used to diagnose Mycoplasma pneumoniae?
complement fixation serology
most common cause of pneumonia in infants (>1month)
respiratory syncytial virus
The P1 terminal attachment factor on Mycoplasma pneumoniae has a high affinity for which host receptors?
sialoglycoprotein or sialoglycolipid receptors
What’s the treatment for Haemophilus influenzae?
ampicillin
Rhinovirus characteristics:
- non-enveloped
- icosahedral capsid
- positive sense ssRNA
lobar pneumonia is characterized by:
consolidation of an entire lobe of the lung
most common cause of croup
human parainfluenza virus (HPIV)
Common causes of pneumonia in neonates (0-1 month):
-e. coli -group b strep (strep. agalactiae)
Mycobacterium tuberculosis survives and thrives intracellulary in which cell type?
alveolar macrophages
What causes scarlet fever?
erythrogenic toxin carried by bacteriophage; it’s a hypersensitivity reaction to the toxin itself (the actual toxin by itself doesn’t cause the problems)
common cause of pink eye
adenovirus
Coronavirus characteristics:
- enveloped
- helical capsid
- positive sense ssRNA
What’s the treatment for coccidioidmycosis?
•Amphotericin B, itraconazole, fluconazole
How will an older (chronic) PE appear on CT?
recanalized; see concentric circles around the clot
Most common cause of pneumonia in people with COPD
moraxella catarrhalis
Morphology of Acinetobacter baumannii:
gram negative bacilli
most common cause of atypical pneumonia
Mycoplasma pneumoniae
What are the Jones criteria for acute rheumatic fever?
-carditis -polyarthritis - erythema marginatum -subcutaneous nodules -sydenham chorea (in first aid, not lecture)
How does pertussis toxin work?
- uncouples G protein mediated signal transduction (increases cAMP)
- increases respiratory secretions and mucus
- inhibits phagocytic function and migration
can cause a chronic granulomatous cervicofacial infection
actinomyces
Morphology of pseudomonas aeruginosa:
gram negative bacilli
What forms the pseudomembrane in diphtheria?
exudate of bacteria, inflammation, and dead cells
Which bacteria cause pneumonia in newborns?
streptococcus agalactiae (group B streptococcus)
causes pseudomembranous pharyngitis that can interfere with breathing
Corynebacterium diphtheriae
What’s the treatment for Mycoplasma pneumoniae?
erythromycin, doxycycline
What’s the treatment for Chlamydia psittaci ?
erythromycin or doxycycline
Why don’t Mycoplasma pneumoniae show up on gram staining?
they don’t have a cell wall
What’s the best test available to determine if you have a mycobacterium species present?
species specific DNA probes. This is important b/c you need to figure out which species you have, as some have specific antibiotic resistance profiles
Interstitial (atypical) pneumonia is characterized by:
diffuse interstitial infiltrates
What’s the treatment for Chlamydia pneumoniae?
erythromycin, doxycycline, levofloxacin
Mycoplasma pneumoniae don’t have a cell wall, but what do they have that stabilizes their bacterial membrane?
sterols
Describe the vaccine for Bordetella pertussis.
DTaP – acellular pertussis vaccine
•contains: Inactivated Pertussis toxin (PT), pertactin (adhesion molecule), FHA (adhesion molecule)
classically results in a right lower lobe abcess
aspiration pneumonia
What’s the morphology of Bordetella pertussis?
tiny, gram negative coccobacilli
How is acute pulmonary embolism diagnosed?
CT pulmonary angiography
What is the hallmark of pneumonia caused by strep. pneumoniae?
rust colored sputum (from blood in sputum)
Morphology of Cryptococcus neoformans:
budding yeast cells with large capsules, visualized by india ink
How can you identify Blastomyces dermatitidis?
thick walled broad based budding yeast
1 killer of AIDS patients worldwide.
TB
What about strict anaerobes makes them so sensitive to oxygen?
they lack superoxide dismutase (SOD) which protects cells from toxic oxygen radicals
What type of granuloma does TB cause?
caseating granuloma
Acute glomerulonephritis follows a ___ infection with strep. pyogenes.
skin infection (impetigo)
What type of hemolysis is strep. pyogenes characterized by?
beta hemolysis
How can you ID Histoplasma capsulatum?
- macroconidia
- intracellular yeast in lungs
Morphology of Nocardia species:
stain poorly with gram stain, but are recognized by acid-fast staining appearing as delicate hyphae
Morphology of Peptostreptococcus:
gram positive cocci
describe the appearance of strep. pneumoniae
encapsulated, gram [+], diplococci
What’s the vaccine for TB?
•BCG (Bacille of Calmette and Guérin)
—-Live, attenuated M. bovis
—-Do not give to immunosuppressed pt because it is live
What’s the treatment for blastomycosis?
•Amphotericin B, itraconazole, fluconazole
most frequent cause of common cold
rhinovirus
What’s the treatment for Legionella pneumophila infection?
erythromycin or fluoroquinolones
What cause the symptoms following Mycoplasma pneumoniae infection?
Sxs due to activity of mycoplasma on cells= Triggers cell to produce H2O2 and reactive O2 =Detrimental to host cell membrane and cytoplasm disruption —->Eventually leads to destruction of the cell
Describe the morphology of Haemophilus influenzae?
gram negative coccobacillus
It is important to remember that the most common causative pathogen implicated in SECONDARY bacterial pneumonia following viral infection (classically influenza) is ______.
staph aureus
