Bugs- Respiratory Flashcards
Which viruses are in the paramyxovirus family?
Parainfluenza
RSV
Measles, Mumps
Macrolides
Azithromycin
Clarithromycin
Erythromycin
Resevoir for bacteriodes
Human colon
Mechanism of action of influenza virus
Hemagglutinin (binds sialic acid and promotes viral entry)
Neuraminidase antigens (promotes progeny virion release)
Pseudomembranous phayngitis with lumphadenopathy, myocarditis, and arrythmias
C. Dip
Cell wall lacks muramic acid
Chlamydia
Cannot make ATP
Chlamydia
Macrolides mechanism
Inhibit protein synthesis by blocking translocaton; bind to the 23 rRNA of the 50S ribosomal subunit
How is an infection with m.avium intracellulare treated?
Macrolide plus ethambutol
Gram -
Coccobacillis
H. influenza
Bordetella pertussis
Pasteurella
Brucella
Francisella tularensis
How is H. influenza cultured?
On chocolate agar, which contains factors V (NAD+) and X(hematin) for growth
Can also grow with S.aureus
Macrolides
Azithromycin
Clarithromycin
Erythromycin
Why is brodetella often mistaken for a viral infection?
Due to lymphocytic infiltrate resulting from immune response
Gram positive rods with metachromatic granules
Cornebacterium diphtheriae
Which DNA viruses are enveloped?
Herpresviruses
Poxvuris
Hepadnavirus
Another name for croup
Acute laryngotracheobronchitis
Obligate intracellular bacterium
Chlamydia
Rickettsiacae
Mechanism of resistance to macrolides
Methylation of 3S rRNA-binding site prevents binding of drug
Large, boxcar-like, gram positive, spore forming rods
B. anthracis
What are the three clinical stages of Bordetella?
- Catarrhal- low grade fevers, Coryza (inflammation of nose)
- Paroxysmal- paroxysms of intense cough followed by inspiratory whoop, posttussive vomiting
- Convalescent- gradual recovery of chronic cough
Pathogenesis of Pseudomonas
- Endotoxin : inflammation in tissues
- Exotoxin A ADP: Riboxylation of eEF-2, inhibiting protein synthesis
- Capsule/slime layer: Formation of pulmonary microcolonies; difficult to remove by phagocytosus
How is TB treated?
Prophalaxis: Isoniazid
6-9 months: Rifampin, isoniazid, Prazinamide, Ethambutol
True or False. All negative-stranded RNA viruses are enveloped
True
__________ prevents pneumonia caused by RSV infection in premature infants.
Palivizumab
Mechanism of action of palivizumab
Monoclonal antibody against F protein
What ion is low in legionnaire’s disease?
Sodium, leading to hyponatremia
Naked positive stranded RNA viruses
Calcivirus
Hepevirus
Picornavirus
- Patient with acute respiratory distress
- Travel to Far East or Toronto
- Winter/spring peak incidence
SARS-CoV
*Coronaviridae
Treatment for Bordetella
Macrolides
TMP–SMX, if allergic to macrolides
Aerobic, motile, catalase +, gram - rod, oxidase +
Pseudomonas
Gram positive, a-hemolytic, lancet-shaped diplococci, optochin sensitive
Strep pneumonia
How should bacteriodes be treated?
Metronidazole
Clindamycin
Cefoxitin
What type of virus is the influenza virus?
Family: orthomyxoviruses
ssRNA, negative sense, 8 segments
Enveloped
Helical
Makes limited ATP
Rickettsiaceae
What type of virus is adenovirus?
dsDNA and linear
No envelope
What are the symptoms of adenovirus?
- febrile pharyngitis- sore throat
- Acute hemorrhagic cystitis
- Pneumonia
- Conjunctivitis
- Gastroenteritis
- Myocarditis
Where does the orthomyxovirus replicate?
Nucleus and cytoplasm
Treatment for B. anthracis
Fluroquinolone (Ciprofloxacin)
Doxycycline
True or false. All negative-stranded RNA viruses are linear/
false
*They’re all helical
How is nocardia treated?
Sulfonamide
TRP-SMX
Does Rhinovirus infect the GI tract?
No. It is acid labile (destroyed by stomach acid)
What cells does b.pertussis attach to?
Nasopharyngeal ciliated epithelial cells
*Toxin damages respiratory epithelium
Mechanism of action of macrolides
Binds 50 S subunit and inhibit protein synthesis by blocking translocation
Cavity bronchopulmonary disease. Cause? Symptoms?
- `Nocardia
- Cough, fever, dyspnea, localized or diffuse oneumonia with cavitation
Bordettela virulence factors
Pertussis toxin disables Gi
Adenylate cyclase toxin increases cAMP
Tracheal cytotoxin
How is C. Diph treated?
Erythromycin and antitoxin
Why is Klebsiella difficult to treat?
Frequent abscesses
Gram -, aerobic coccobacillus
Bordetella pertussis
Mechanism of action of tetracyclines
Bacteriostatic; bind to 30S subunit and prevent attachement of aminoacyl-tRNA
What type of viruses are paramyxoviruses?
ssRNA, negative sense, linear, helical
Nonsegmented
Enveloped
Mechanism of resistance to tetracyclines
- Decrease in uptake or increase in efflux out of bacterial cells by plasmid-encoded transport pumps
How is H. influenzae diagnosed?
- Blod or CSF culture on chocholate agar
- PCR
- Antigen detection of capsule (latex particle agglutination)
How is RSV diagnosed?
- Indirect fluorescent antibody
- ELISA
- RT-PCR
Pathogenesis of Bacteriodes
Modified LPS (missing heptose and 2-keto-deoxyoctonate) has reduced endotoxin activity
Capsule is antiphagocytic
Pontiac fever
Mild flu-like symptoms
Cuased by legionella
Aminoglycosides
Gentamicin
Neomycin
Amikacin
Tobramycin
Streptomycin
Which RNA viruses are not enveloped?
Reoviruses
Picornavirus
Hepevirus
Calicivirus
_____________ strains of H. influenza are most common causes of mucosal infections as well as invasive infections.
Nontypeable
Pathogenesis of B. anthracis
Anthrax toxin
- Protective antigen (B compenent)- mediates entry of LF or EF into eukaryotic cells
- Lethal factor- kills cells
- Edema factor- adenylate cyclase
How is parainfluenza virus diagnosed?
RT-PCR
What type of virus is papillomavirus?
dsDNA, circular
No envelope
Gram postive, aerobic, non-spore forming rods
C. Diphtheria
How is legionella detected?
Presence of antigen in urine
Labs may show hyponatremia
Narrowing of uper trachea and subglottis leads to characteristic steeple sign on x-ray
Acute laryngotracheobronchitis (croup)
Salmon-colored sputum
S. Aureus
Legionnaires’ disease
Severe pneumonia (often unilateral and lobar), fever, GI and CNS symptoms.
Common in smokers and in chronic lung disease
Adverse affects of macrolides
- GI motility issues
- Arrhythmia caused by prolonged QT interval
- Acute cholestatic hepatitis
- Rash
- Eosinophilia
- Increases serum concentration of theophylline, oral anticoagulants
- Clarithromycin and erythromycin inhibit cytochrome P-450
Segmented viruses
Bunyaviruses
Orthomyxovirus
Arenavirus
Reovirus
Tetracyclines should not be taken with…
Milk, antacids, or iron-containing preparations becuase divalent cations inhibit drugs’ absorption in gut
Only live, non attenuated vaccine
Adenovirus
- Military recruits
- Enterocoated capsule
- Protects entire mucosa
C. Diph toxin-producing strains have ___________.
B-prophage
What type of virus is rhinovirus?
Family: Picornovirus
ssRNA, positive sense, no envelope
Severe croup can rsult in ____________ secondary to upper airway obstruction.
Pulsus paradoxus
Gram positive filamentous bacilli, aerobic, partially acid fast
Nocardia
Mechanism of action of paramyxovirus?
F (fusion) protein, causes respiratory epithelial cells o fuse and form multinucleated cells
Mechanisms of aminoglycosides
- Bactericidal; irreversible inibition of initiation complex through binding to the 30S subunit
- Also blocks translocation
- Ineffective against anaerobes
Steeple sign
Parainfluenza
What bugs are most likely to cause a superinfection with the influenza virus?
S.aureua, S. pneumonia, and H. influenza
Vaccine for H. influenza
Vaccine contains type b capsular polysaccharide conjugated to diphtheria toxoid or other protein. Given between 2 and 18 months of age
Pulmonary symptoms of B. antracis
- Life-threatening pneumonia
- Cough, fever, malaise, and ultimately facial edema
- Dyspnea, diaphoresis, cyanosis, and shock with mediastinal hemorrhagic lymphadenitis
Pathogenesis of group A Strep
- M protein
- Hyaluronic acid: Non-immunogenic
- Streptolysin O: immunogenic, hemolysin/cytolysin
How is Bacterioides transmited?
Endogenous from bowel defects, surgery, or trauma
Gram positive
Coagulase positive
B-hemolytic
Cocci in clusters
S. Auerus
Vaccines for S. Pneumoniae
Pediatric
- 13 serotypes; Conjugated to diptheria toxoid
- 23 serotypes; polysaccharide
Mycobacteria tuberculosis Mechanism
Cord factor creates a “serpentine cord” appearance in virulent M. tuberculosis strains; activates macrophages and induces release of TNF-a. Sulfatides (surface glycoproteins) inhibit phagolysosomal fusion.
Adverse efects of teracycline
- GI distress
- Discoloration of teeth and inhibition of bone growth in children
- Photosensitivity
*Contrindicated in pregnancy
Route of transmission for CMV
Congenital, transfusion, sexual contact, saliva, urine, transplant
Most important virulence factor for H. Influenzae
Polysaccharide capsule (type b capsule is polyribitol phosphate