micro 3 Flashcards
typical pneumonia is caused by bacteria that
not intrinsically resistant to beta lactams
can be grown on lab media
what two MO can cause pneumonia without R/F
H.Influenza and S.Pneumonia
what are the R/F that cause pneumonia in MO
Hospital admission old age aspiration background of lung disease immunocomprimise
important things about s.aureus
what is MRSA AND MSSA treated with
cavitary, abcessing and pneumatocele
MRSA :
MSSA: FLucloxacillin
MRS; Vancomycin
important things about M. catarrhalis
treatment too
oxidase positive and diplococcus
augmentin (clavulunic acid / amoxacillin)
what are enterobacterales members
k.pneumonia and E.coli
MDR organisms of enterobacterales and what is the treatment for each
AmpC and ESBL :temocillin and meropenem
CRE : high dose meropenem and ceftazidime/avibactam
pseudomonas aeroginosa imp things
oxidase positive
non fermenter
motile
virulence factors of p. aeroginosa
adhesins and toxins and enzymes : lasA and lasB Elastase phospholipase C Exotoxin A (ETA) Exoenzyme T and S Alkaline protease
what are the diffusable pigments of p. aeroginosa
pyocyanin ; blue, ROS production
pyoverdin ; green , siderophore to bind to iron and release virulence factors
pyomelanin; dark brown
pyorubin; red brown
what are the clinical features of pseudomonas
lung ; necrotizing bronchopneumonia
skin ; burn colonization , hot tub folliculitis , ecythema gangrenosum and hot foot syndrome
eyes ; corneal ulcers or keratitis following corneal injury
ear; malignant otitis externa
swimmers ear (otitis externa)
chronic otitis media
why can pseudomonas be easily identified
positive oxidase result
pigment production
grape like odor
how is p. aeroginosa resistant
enzymatic inactivation
impermeability
efflux pumps
how to treat pseudomonas and MDR type
normal ; piperacillin / tazobactam (tazocin )
or ceftazidime
MDR ; ceftolozane / tazobactam
Burkholderia charac.
non fermenter
motile
gram negative bacili
oxidase negative
types of Burkholderia and brief explain
B. cepacia complex (BCC) : genomovars cause infection in CF patients and CGD patients
B.pseudomallei : meliodosis cause necrotizing pneumonia
treatment option for Burkholdria
ceftazidime and carbapenem
acinetobacter spp charac
immotile
gram negative coccobacillary
imp member of acinetobacter
a. baumanii that can develop antibiotic resistance
what infection that acinetobacter cause
pneumonia
stenotrophomanos maltophilia what does and cause and how is it treated
pneumonia
co-trimoxazole
what are atypical pathogens
intrinsically resistant to beta lactams
could not be diagnosed by conventional cultures
radiological picture is worse than the status of the patient ( walking pneumonia )
lehionella pneumophilia is an atypical bacteria that has what charact.
fastidous
is l. pneumophila a facultative intracellular
yes . within alveolar macrophage and epithelial cells
how does l. pneumophila enter macrophage
CR3 receptor
l. pneumophila escape intracellular killing by imhibiting phagolysosome fusion
true
l. pneumophila may survive long in moist env. even in the presence of disinfectant (chlorine) or high temp
yes
what can l. pneumophila do
legionnaires and pontiac fever
what is legionnaires incubation period and manifestions
period ; 2-10 days
clinical ; acute illnes after incubation and sever feautures of pneumonia
extrapulmonary involvement
mortality rate 15% healthy and 75 % immunocomprimised
what is pontiac fever
mild flu like illness that does not involve lung
how to diagnose l. pneumophila
LPS antigen in urine specific for serogroup 1
culture needs L. cysteine , iron and BCYE and needs 3-5 days
how to treat l. pneumophila
fluoroquinolones ( levofloxacin )
copper silver ionization , superheating and hyperchlorination are used in l. pneumophila
true
what do mycoplasma and ureaplasma have in common
inherently lack cell wall and sterols in cell membrane
is mycoplasma pneumonia part of normal flora
no
smallest free living bacteria that is strictly aerobic
mycoplasma pneumonia
virulence of m. pneumonia
adhesion protein ( P1 adhesin) formation of cold agglutinins ( IgM autoab that bind to RBC surface at 4c leading to hemolysis)
secondary complications of m. pneumonia
steven johnson syndrome , hemolysis, meningoencephalitis, arithritis
what is the method of choice for diagnosing m. pneumonia
PCR
diagnosis m. pneumonia serology
fourfold increase in IgG titer between acute and convalescent serum samples
diagnosis of M. pneumonia culture
must contain serum to supply sterols
must contain yeast extract for nucleic acid precursor and it need 2-3 weeks
Mycoplasma treatment
macrolide
chlamydia is an obligate intracellular bacteria and is an energy and nutrient parasite
true
pathogenic species of chlamydia
c. pneumonia
c. psittaci
c. trachomatis
inside host cells chlamydia spp displays two forms within inclusions
elementary body (EB) ; infectious stage reticulate body ( RB) : forms after microbial entry when it replicates it forms EB that will be expelled out
c. pneumonia features
no animal reservoir other than humans
most cases are asymptomatic or mild
sinusitis pharyngitis and pneumonia
c. psittaci features
natural reservoir is birds
spread through monocyte macrophage system causing hepatospleenomegaly, pneumonia, CNS, eye and heart involvement
c. trachomatis features
affect genital tract and eye
cause of infant pneumonia 2-3 weeks after birth
clinical course for weeks but radiological pic for months
nucleic acid used for what and serology for what in diagnosing chlamydia
PCR c. trachomatis and pneumonia
serology ; psittacosis
what is used against chlamydia
macrolide , tetracycline and fluoroquinolone
