KG - Microbiology Exam 2 Flashcards
viruses that cause ARD (common cold)?
adenovirus (30-40%)
rhinovirus (25%) - some say 50%?
coronavirus (10%)
viruses that cause ARD (common cold)?
adenovirus (30-40%)
rhinovirus (25%) - some say 50%?
coronavirus (10%)
diagnosis ARD?
clinical
treatment ARD?
symptomatic only
NO Zicam
treatment rhinovirus specifically?
zinc gluconate (symptomatic) Picovir - not mass market yet
viruses that cause flu?
influenza A, B, C
prevention influenza?
vaccines - 2 type As, 1 type B
now 2 As, 2Bs - recent change?
diagnosis influenza?
rapid viral ID tests for antigen swabs
– can have false negatives early on
treatment influenza?
amantadine & ramantadine = type A (stops uncoating & penetration)
oseltamivir & zanamivir = type A & B (stops spread, release)
complications influenza?
pneumonia, Reyes, Guillain-Barre
antigenic drift? (flu)
point mutations, H or N
antigenic shift? (flu)
genome sequence recombinations - most important to pandemics
viruses that cause Chlamydiae?
C. trachomatis, C. pneumoniae
risk factor for C. trachomatis? prophlaxis?
infected mother, prophylaxis = silver nitrate eye drops
common infectious state/pop of C. trachomatis?
infants 3 wks post birth
C. pneumoniae also causes ___
bronchitis, pneumonia, sinusitis, & associated w/ atherosclerosis
viruses that cause Chlamydiae?
C. trachomatis, C. pneumoniae
risk factor for C. trachomatis? prophlaxis?
infected mother, prophylaxis = silver nitrate eye drops
common infectious state/pop of C. trachomatis?
infants 3 wks post birth
what syndrome is associated w/ C. trachomatis?
Reiter’s Syndrome
two forms chylamidiae?
elementary body = infectious agent
reticulate body = growing form
cause Croup?
PIV1 > PIV 2»_space;> RSV
age typically of croup?
6-18 months old
diagnosis croup?
direct FAB test
- must have direct viral isolation from throat/nasal swabs
treatment croup?
symptomatic
describe P. aeruginosa
G- bacilli
encapsulated
pigment producer - pyocyanin, pyoverdin (these = VF)
signal sign on CXR croup?
steeple sign
PIV causes ____
croup, OM, parotitis
describe PIVs
paramyxovirus, nonsegmented neg sense ssRNA, enveloped, 4 serotypes
- virion enveloped by protein spikes
- hemagglutinin & neuraminidase activities on same peplumed molecule
- NF proteins cause syncytia formation
most vulnerable to PIV?
immunocompromised
diagnosis PIV?
direct FAB test
- must have direct viral isolation from throat/nasal swabs
lifelong immunity to PIV?
NO, but usu mild later on
treatment PIV?
symptomatic
vaccine PIV?
NONE available
group common of winter outbreaks RSV?
infants < 1 yo (peak 2-3 months old)
most common cause LRIs?
RSV
why symptoms in RSV?
infection of epithelium of resp tract –> causes inflammatory response of IgE and Tcells
risks for RSV?
birth 3-4 months prior to winter, kids w/ underlying dz, premature birth, cardiac/resp abnormalities
- also immunocompromised adults
diagnosis RSV?
rapid antigen test & immunofluorescence assay
serology not common anymore
treatment RSV?
monoclonal immune globulin for high risk pts (Palivizumab)
Ribavirin (controversial)
cause Otitis Externa?
P. aeruginosa & S. aureus
describe S. aureus
G+ cocci
encapsulated
COAG +
beta-hemolytic (+ if you can see through plate)
diagnosis OE?
exam, gram stain
treatment OE?
remove debris, topical antibiotics, oral antibiotics if fever, systemic analgesics
describe VOLUTIN staining for diphtheria?
Volutin = metachromic (volutin) granules
describe S. pneumoniae
G+ diplococci lancet
encapsulated
alpha-hemolytic (can’t see through plate)
optochin sensitive
describe H. influenzae
G- coccobacilli
non-typeable strain
describe M. catarrhalis
G- diplococci
oxidase positive
beta lactamase producer
diagnosis AOM?
clinical, tympanocentesis to aspirate fluid in severe pts, culture/stain
diagnosis sinusitis?
clinical/hx, nasal cytology, CT, allergy testing
treatment AOM?
amoxicillin, tubes for chronic
treatment sinusitis?
varies depending on cause - irrigation, analgesics, OTC decongestants, antibiotics, steroids, surgery
cause diphtheria?
Cornebacterium diphtheriae
describe cornebacterium diphtheriae
G+ pleomorphic bacilli
metachromic gracules
aerobic on blood agar
“Chinese letter appearance”
signs diphtheria (cutaneous)?
non healing ulcers
signs diphtheria (respiratory)?
sudden onset, malaise, fever, lymphadenitis, BULLNECK, PSEUDOMEMBRANE
diagnosis diphtheria?
clinical, culture & staining
describe culture: Loeffler’s medium?
for diphtheria:
supports growth and enhances formation of volutin granules
major complication pertussis?
pneumonia
- also vomiting, increased intracranial pressure, seizures, encephalopathy
describe GRAM staining for diphtheria?
Gram = club shaped, G+ bacilli
describe VOLUTIN staining for diphtheria?
Volutin = metachromic (volutin) granules
treatment diphtheria?
antitoxin, erythromycin, isolation, & vaccination once pt recovers
VF diphtheria?
AB exotoxin – B binds to receptors, is endocytosed, vesicle acidifies, A subunit released, A subunit inactivates EF-2 ADP ribosylation & halts protein synthesis
cause Pertussis?
Bordetella pertussis
describe bordatella pertussis
G- coccobacilli
aerobic
VF: 2 adhesins, 4 exotoxins
what do adhesions do in pertussis?
mediate attachment to integrins & colonization of ciliated respiratory epithelium
pertussis exotoxins (4)
- pertussis toxin (AB exotoxin) = lymphocytosis
- adenylate cyclase toxin = causes decreased chemotaxis
- dermonecrotic toxin = vasoconstriction, necrosis
- tracheal cytotoxin = kills ciliated resp epithelial cells
describe stage 1 pertussis
catarrhal stage: inflamed mucosa, contagious, 7-10 day incubation, nonspecific URI
describe stage 2 pertussis
paroxysmal stage: attacks/spasms w/ “whoop” sound that can be followed by vomiting, labored inspiration, 2-4 wks
describe stage 3 pertussis
convalescent stage: gradual recovery wks - months
diagnosis pertussis?
presumptive diagnosis = ELISA serology
definite diagnosis = culture or PCR
treatment pertussis?
erythromycin (or Bactrim)
what cultures are used for Pertussis?
Bordet-Gengon agar
Regan-Lowe agar