Bacterial Pathogens of Resp tract Flashcards
morphology mycoplasma pneumoniae
no cell wall (no gram stain)
coccoid
obligate aerobe
produces P1 adhesion
morphology mycoacterium tuberculosis
acid fast rods (gram postive)
wall containign mycolic acids and lipoarabinomannan
DT also a carrier for conjugate vaccines _____ (mechanism)
Hib-CRM 197 point mutation in DT that inactivates toxin
diseases associated with cornebacterium diphtheriae
non-toxin strains - localized infection > pseudo membrane
toxin producing strains cause systemic disease
presentation Legionnaires vs Pontiac
(associations, treatment, seasonality)
legionaires with underlying pulmonary disease
legionnaires requires antibiotics, higher mortality
legionaires in late summer or autmn (endemic throughout year) (pontiac has no seasonality)
morphology stetococus pyogenes (group a strep)
Group A lancefield
Gram pos cocci chains
catalase neg
betahemolytic
M proteins
hyaluronic acid capsule
morphology strep pneumoniae
no lancefield designation
Gram pos
cocci (often diplococci)
alpha hemolytic (partial lyse, green colonies)
alpha hemolytic, causes green stain on agar
streptococcus pneumoniae
mechanism of disease H influenzae
OMPs HMW1+2
LOS
process-
OMPs HMW1+2 outer membrane proteins bind
LOS has endotoxin activity
invade submucosa > localized inflammatory response
mechanism of disease Staph aureus
LTA
Coagulase
hyaluronidase
Lipases and nucleasesctin
Protein
normal component of nasopharyngeal flora
LTA binds epithelial fibrone** A **binds FcR - inhibit Ab clearnance
Coagulase converts fibrinogen to fibrin
hyaluronidase promotes spread
Lipases and nucleasesctin
Protein
associated diseases Bordetella pertussis
whooping cough
RT diseases of staphylococcus aureus
**pneumonia **- young + elderly w/pulmonary disease
(acquired from aspiration of oral secretion or hematongenous spread from distant infection site)
scarlet fever in s. pyogenes due to
pyrogenic enxotoxins (super antigens)
(not bacterial dissemination)
diseases of mycobacterium tuberculosis
TB (various manifestations)
diseases of Mycoplasma pneumoniae
tracheobronchitis
atypical pneumonia
diseases of legionella penumophila
legionnaire’s - pneumonia like symptoms
pontiac fever - flu like
H influenzae morphology
small gram negative rods
require heme and NAD for growth
polysaccharide capsule
use pili and OMPs to bind epeithelial
staph aureas morphology
gram pos cocci
clusters
catalase pos
polysaccharide capsule with surface protein A
morphology pseudomonas aeruginosa
gram negative rod
single polar flagella
oxidase positive
form biolfilms
opportunistic
vaccine for c. diphtheria
formalin inactivated diptheria toxin
diseases of pseudomonas aeruginosa
lung infections of cystic fibrosis patients
others
morphology corynebacterium diptheriae
gram positive
pallisades
diseases of streptococcus pneumoniae
lobar pneumonia
sinusitis
otitis media
mechanisms of disease Strep pneumonia
**surface proteins **bind epithelial
**secretory IgA proteae **disrupt IgA-mediated clearance
**Pneumolysin - **activates alternative complement path (alpha hemolytic) also supressives oxidative burst and destroys ciliated epithelial cells
morphology Legionella pneumophila
gram negative rod
opportunistic
single polar flagellla
mechanism of disease bordetella pertussis
bind ciliary epithelium >
>PTc alters andenylate cyclase activity >
> ADP ribosylates Gia > elevate cAMP >
> increased secretion and mucus production >
other factors damage mucocilliary elevator
diseases streptococcus pyogenes
Pharyngitis
scarlet fever - strep pharyngitis + erhythematous punctiform rash
vaccine to H influenze
type B for polysaccharide capsule
mechanism of disease S pyogenes
surface proteins **M, F, LTA **adhere in pharynx
Streptolysin O and S lyse leukocytes, platelets and erythrocytes (beta hemolytic)
**pyrogenic exotoxins **mediate pyrogenicity (scarlet fever super ag)
mechanism of disease M pneumoniae
P1 adhesion to upper airway
accumulation of toxic metaboites + lipid oxidation
destroys cilia > inhibiting clearence
inflammatory response
mechanism of disease N. meningitidis
capsule - prevent pahgocytosis + complement fixation
Type IV pili - colonization of nasopharynx
Endotoxin - most clinical symp
LOS - endotoxin
mechanism of disease P aeruginosa
opportunistic
biofilms
procyanin/pychelin induce ROI release
Exotoxins ExoA,U,Y,S destroy host tissues
proteases, elastase, DNAase Lipase
diseases of h influenzae
pneumonia
sinusitis
otitis
epiglottis
non-encapsulated strains limited to URIs
(lower more common in kids or underlying condition)
synthesized by corynebacterium diptheriae
diptheria toxin DTx
AD{ ribosylates EF-2 (inhibits protein synth)
pili
stages of whooping cough (bordetella pertussis)
catrrhal
paroxysmal
convalescence (few organisms in tract)
synthesized by bordetella pertussis
pertussis toxin PTx
adhesions including FHA
pertactin
pili
diseases associated with neisseria meningitidis
phayngitis pneumonia
progression to meningitis
incubation period
legionnaires
pontiac fever
legionnaires = 2-10days
pontiac - 1-2 days
streptococcus pyogenes ____ = completely lyses RBCs underlying colony
beta hemolytic
asymptomatic carriers of bordetella pertusis
adults (then transfer to young)
vaccines for strep pneumoiae
adults+2yo children - 23 capsular polysaccaride vaccine
children < 2 - 13valent conjugated vaccine
N meningtidis vaccine
polysaccaride capsule
against sialic acid in sero group B (protein based)
Polyvalent against serogroups A C Y and W135
MCV4 conjugate vaccine - 55 - 2yo
MPSV4 capsule vaccine - 55 and older
mechanism of disease L pneumophila
survives inside alveoli
kills infected host cell via phosphatase, lipase, nucleases
mechanism of disease c dihtheriae
pili adherence to resp epithelium
replicate at surface of epithelium
invasion > toxigenesis (if toxin strain) >
> systemic disease (if toxin strain)
morphology Bordetella pertusis
Gram neg coccobacillis
strict aerobe
morphology neisseria meningitidis
location
gram neg diplocci
oxidase pos
polysaccharide capsule
pili
(nasopharynx of healthy indiv.)
mechanism of disease M tuberculosis
latency in granulomas
symptoms due to host response
long chain fatty acids (mycolic acids, liparabinomanan) protects
cord factor inhibits PMNs
