Microbiology of Upper Respiratory Infections Flashcards
Rhinitis
ssRNA+ (naked)
Nasal stuffiness, HA, neeze
RHinovirus infects cells in nasal passage…columnar epithelial cells sloughed off
2ndary bacterial infectiou occurs IF you get blockage of sinus ostia or ET
DOn’t spread further down bc too farm
Fingers are best spread…enter through nasal mucosa and eye
Survive a long time on the skin
Adenovirus
dsDNA (llinear) naked
Pharyngitis with conjunctivitis and fever
More likely in children, YA or institutional
Acute rhinosinusitis
Inflammation of mucos of nasal passages AND at least one of paranasal sinuses
Sneezing, rhinorrhea, nasal congesiton, drip, facial pressure, fever, sort through
Most common - virus
Acute bacterial (preceded by viral) - S. pneumo or Hib
Obstruction of paranasal ostia impedes drainage of mucus secretions —- bacteria grow
Dx - sx of rhinosinusitis that worsen after 5 days and persist beyond 10 days or worse after initial improvement
Mucormycosis
Mucor or rhizopus
Sporanglospores breathed
RHinocerebral infarction starts in nasal caivty…black ulcers
diabetes (DKA), malignancies, immunosuppression
Otitis media
Ear pain, pressure, middle ear effusion
More likely in children bc shorter, flexible, horixzonal ETs…effusious in ET become infected with nasopahryngeal contents
Usually preced by viral URI that causes swelling of lining of inner ear
S. pneumo, Hib
Otitis externa
Swimmers ear
Excesvie moisture in ear canal raises pH and removes cerumen
Psuedomonas
Pharyngitis
Fever, sore throat, edema, hyperemia of tonsils and pharyngela walls with painful swalling
Viral - virsues gain access to mucosal lining nasopharynx and replicate, causing damage (cox, rhino)
Bacterial - normal Strep pyo…attaches to mucosal cells via M protein
Strep pyo structure
Hyaluronic acid capsule (non immunogenic)
M-protein required for virulence…extend from anchor in cell membrane
How to diff Aureus and pyogenes
Hemolytics
Catalase pos - aureus
Beta - S. pyo…clear
Alpha - green (partial)…S.pneumo
Diptheria
Corynebacterium diptheriae
Worldwide dist
Chinese lettering
Bullneck appearance due to LAD, pahryngeal pain, cough
Lysogenic phage encoade A+B toxin (irojn regulated)
Thick adherett psedomembrane that is composed of cell debris…coats throgh and can obstruct airway
Grow on cycteine-tellurite agar
A+B toxin entry
Binding, recpetor mediated endocytosis, acidification and release of A subunit across membrane
Exotoxin A
Diptheria and Pesudomonas
Uses ADP ribosylation ot inhibit protein syntehsi
Epiglottitis
Hib (kids)
Group A strep (adults )
Hib colonizes pharynx and enrters epiglottis via brekas in mucosa…thumb sign on XDysphagia, dysphonia, drooling, distresss
RAPID ONSET
HIB needs chocolate agar to grow
Hib virulence factors
Pilli
Capsule that inhibits phagocytosis
Capsular PS antigens
Grows on chocolate agar (fastidious)
Whooping cough
Bordetella pertussis
Infection of large bronchi
1-2 weeks of URI
2-4 weeks of paroxysmal cough followed by whoot or vomiting
Up to 6 months to get ridd of
Grow non B-G or R-L agar
High WBC count with lymphocytosis in children
A-B toxin that activates adenylate cyclase through GPCR
