Micro review Flashcards
Bordetella purtusis
aka whooping cough
highly contagious
gram neg aerobic coccobacillys capsulate
humans only known reservoir
Bordetella purtusis phases
catarrhal
paroxysmal
convalescent
catarrhal phase
rhinorrhea
lacrimation
conjunctival injection
low grade fever for days
paroxysmal phase
uncontrollable expirations, followed by gasping inhalation (whoop)
post cough cyanosis, gagging, vomiting
last up to 4 weeks
convalescent phase
reduction in frequency and severity of cough, can last from weeks to months
Bordetella purtusis Tx
supportive
azithromyocin
chemoprophylaxis to control outbreaks
klebsiella pneumonia
gram negative, non-motile, capsulate rods
facultative anaerobe
klebsiella infections
UTI soft tissue endocarditis CNS severe bronchopneumnia CAP and HAP (cavitary lung lesions) currant jelly sputum
M. cartarrhalis
gram neg bacteria chocolate agar diplococci catalase + oxidase + penumonia, especially in elderly otitis media
N. meningitidis
aerobic gram neg kidney shaped diplococci, capsule oxidase + ferments maltose and glucose thayer martin and chocolate agar commensal of URT
clinical manifestation of N. meningitidis
meningitis septicemia pneumonia septic arthritis, pericarditis, chronic bacteremia conjunctivitis
N. meningitidis Tx
penicillin
3rd generation cephalosporins
Pseudomonas
aerobic gram neg rod
pyocyanin
primarily nosocomial
in hospital can colonize moist surfaces
Pseudomonas infections
HAP, VAP community aquired infections associated w/hot tubs, whirpools, swimming pools, extended contact lenses otitis externa puncture wounds thru shoes endopthalmitis endocarditis UT skin infections, burns, ecthyma gangreosum
pseudo bacterial factors
exo and endotoxins type III secreted toxins pili flagella proteases phospholipids iron binding proteins exopolysaccharides biofilms pyocyanin
pseudo Tx
extended spectrum penicllin and aminoglycoside combination
Chlamydophilla psittaci
gram neg obligate intracellylar bacteria
macrophages principal host cell
Chlamydophilla psittaci diseases
psittacosis
atypical pneumonia
febrile illness
Chlamydophilla psittaci transmission
aerosolized bird secretions, dust
Chlamydophilla psittaci Tx
tetracyclines
macrolides
FQs
Chlamydophilla pneumoniae
80% of adults seropositive
common in kids <5
atypical penumonia
Chlamydophilla pneumoniae atypical pneumonia
incubation several wks
non productive cough
preceded by nasal congestion, sore throat, and hoarseness
HA
Chlamydophilla pneumoniae labs
normal white count
Chlamydophilla pneumoniae Tx
tetracyclines
macrolides
FQs
Coxiella burnetti
gram neg that infects hosts monocytes
incompletely eliminated after acute infection
will continue to multiply in immunocompromised and endocarditis patients despite high Abs
infects mammals, birds, ticks
Coxiella burnetti spread
animal feces, urine, milk, birth products
survives in environment and can be spread by wind
major outbreaks associated w/sheep and goats during lambing season
Q-fever
Coxiella burnetti 60% seroconvert w/o disease 38% self limited 2% require diagnostic evaluation prolonged fever pneumonia hepatitis rash meningitis, encephalitis, menigioencephalitis, peripheral neuropathy pericarditis, myocarditis
Coxiella burnetti prego
uterine infections and spontaneous abortions
Q fever endocarditis
intermittent fever
vegetations frequently absent
cerebral emboli, renal insufficiency, splenomegaly, hepatomegaly
Coxiella burnetti Tx
Doxy
Doxy + hydroxychloroquine for 18-36 months for endocarditis
Francisella tularensis
infectious zoonosis
small aerobic pleomorphic gram neg bacillius
rabbits, squirrels, muskrats
direct contact, ingestion of water or meat, bite of infected tick or fly, aerosol, NOT human -> human
Francisella tularensis clinical
ulceroglandular glandular oculoglandular typhoidal oropharyngela pneumonic
Francisella tularensis ulcerolglandular
fever and constitutional symptoms swollen lymph nodes that drain an inoculation ulcer formation sore throat patchy infiltrates on CXR
Francisella tularensis glandular
fever
constitutional symptoms
lymphadenopathy
Francisella tularensis typhoidal
fever of unknown cause
Francisella tularensis oropharyngeal disease
uncommon in US
mucous membranes of mouth and pharynx are portal of entry
contaminated water or food
painful exudative pharyngitis and tonsillitis
pharyngeal ulcers
swollen retropharyngeal and cervical lymph nodes
Francisella tularensis pneumonic disease
inhalation exposure
fever, malaise, dry cough, substernal discomfort, pleural effusion, dyspnea, sore throat,
CXR- peribronchial infiltrates to bronchopenumomia w/effusion
hilar adenopathy
Francisella tularensis Tx
gentamicin or streptomycin
doxy
cipro
bacillus anthracis
spore forming gram pos non motle rod aerobic or facultatively anaerobic catalase + hemolysis neg sheep agar zoonotic (goats, sheep, cattle, antelope, kudu, pigs, horses, zebu) soil contaminated w/spores
bacillus anthracis inhalation:
mediastinal adenopathy and widening, pleural effusions, rapidly fatal if not treated w/multiple abx and pleural drainage
bacillus anthracis cutaneous
most common
bacillus anthracis GI
oropharyngeal
intestinal
bacillus anthracis menigeal
nearly always fatal, can occur as complication of inhalation, cutaneous, or GI
bacillus anthracis Tx
multi-drug regimen
pleural drainage
Yersinia pestis
gram neg coccobacillus, microaerophilic, nonmotile, and non-spore forming
rodents and fleas as vectors
prairie dogs
clinical manifestation of plauge
bubonic
septicemic
pneumonic
bubonic plague
swollen tender lymph nodes (boboes) closest to site of initial infection
fever, chills, myalgia, arthralgia, HA, malaise, prostration
untreated- tachycardic, agitation, confusion, delirium, convulsions
septicemic plague
nausea, vomiting, diarrhea, ab pain
DIC
hypotension, renal failure, obtundation
ARDS
pneumonic plague
fever, cough, chest discomfort, tachycardia, dyspnea, bacteria laden sputum, chills, HA, myalgias, weakness, dizziness
respiratory distress, hemoptysis, cardiopulmonary insufficiency, circulatory collapse
death w/in 24hours
Yersinia pestis Tx
streptomycin for penumonic
tetracyclines for bubonic
chloramphenicol for meningitis
leptospirosis
spirochete w/terminal hook
dark field microscopy or silver stain
obligate aerobe
weils disease, pulmonary hemorrhage syndrome
leptospirosis resevoir
persistent renal carriage from rodents, dogs, pigs, cattle, and sheep
colonize renal tubules, excreted in urine, and survives for wks to months in enviroment
leptospirosis transmission
penetrates skin or mucous membranes during contact w/contaminated water, soil, vegetations
leptospirosis early phase
3-7 days fever, myalgia, ab pain, diarrhea, cough, photophobia mm tenderness rash conjunctival suffusion
leptospirosis late phase
aka weils disease jaundice acute hemorrhage renal failure severe thrombocytopenia GI bleeding pulmonary hemorrhage myocarditis aseptic menigitis
lepto diagnosis
agglutination test
leptospirosis Tx
doxy
penicillin
H. influenza
encapsulated gram neg pleomorphic rod aerobic or facultative aanaerobe chocolate agar nasopharyx of adults and kids type B was most common cause of meningitis before vaccines
H. influenza menigitis
children <5f and adults w/skull trauma or CSF leaks
Type B
diagnosis by detecting PRP capsular Ags in CSF
H. influenza epiglottis
life threatening infection in kids thumb print
H. influenza Pneumonia
fever, cough, lobar consolidation
parapneumonic effusion and empyema
smoking risk factor
other presentations of H. influenza
bronchitis (COPD)
acute sinusitis
otitis media
H. influenza Tx
3rd generation cephalosporin
C. diptheriae
gram + bacillus, club shaped
non-spore forming
aerobic
reservoir- throat and pharynx
respiratory diptheriae
incubation of 1-7 days
sore throat, malaise, fever
pharyngeal erythema followed by tonsillar exudate -> grayish membrane tightly adhered and bleeds on attempted removal
C. diptheriae clinical presentation
cervical adenopathy- bull neck
stridor
extension of membrane - airway obstruction
myocarditis, recurrent laryngeal n palsy, and peripheral neuritis
C. diptheriae Tx
erythromycin
antitoxin
legionellas
weakly gram - pelomorphic rod
facultative intracellular
requires cysteine and iron (charcoal yeast extract)
water organism, amebae, air-conditioners
legionellas risk factors
smokers
55+
high alcohol intake
immunosupression
legionaires disease
-fevers, malaise, cough, chills, dyspnea,
-myalgias, HA, chest pain, diarrhea distinguish from other penumonias
mental confusion
pontiac fever
fever sore throat mylagia, HA, extreme fatigue
short duration, lasting on average 3 days
legionellas
Tx of legionella
FQ
azithromycin
erythromycin +rifampin in immunocompromised
dug must penetrate human cells
M. pneumonia
smallest free-living bacteria no cell wall (therefore beta lactams have no effect) sterol containing membrane requires cholesterol for culture military, dorms highest incidence 5-20
M. pneumonia respiratory infection
2-3 wks incubation fevers, malaise, HA, and cough 5-10% progress to pneumonia cough usually non-productive 'walking pneumonia' can also cause Bullous myringitis
M. pneumonia Dx
primary clinical
positive cold agglutinins in 65%
M. pneumonia Tx
macrolides
tetracyclines
S. pneumonia
gram + diplococcus lancet shaped blood agar alpha hemolytic optochin sensitive lysed by bile polysaccharide capsule
S. pneumonia risk factors
influenzae infection COPD CHF alcoholics asplenia
S. pneumonia typical pneumonia
most common causative agent
shaking chills, high fever, rigors, lobar consolidation, rusty (blood tinged) sputum
other manifestations of S. pneumonia
Adult meningitis most common causative agent
otitis media and sinusitis most common causative agent in kids
S. pneumonia pneumonia Tx
beta lactams
macrolides
FQs
Tx of S. pneumonia T meningitis
3rd generation cephalosporin
vancomicin if penicillin reisistant
SARS
coronavirus (second most common cause of common cold)
reservoir- birds and small mammals
virus also found in urine, sweat, and feces
clincial manifestation of SARS
fever >100.4 flu-like illness dry cough dypsnea progressive hypoxia
SARS Dx
clinical Hx and travel Hx (far east or Toronto)
SARS Tx
supportive
50% mortality in elderly
Varicella-Zoster virus
infects epi cells and lymphocytes in oropharynx and URT
infected lymphocytes disseminate
virus enters skin thru endo cells in blood vessels and spreads to epi -> rash
virus remains dormant in CN ganglia and DRGs reactivation -> herpes Zoster
Varicella-Zoster virus Tx
shingles- acyclovir PO
immunocompromised w/shingles- IV acyclovir
aspirin CI due to Ryes syndrome
Varicella-Zoster virus vaccine
CI in:
hematologic malignant neoplasms
AIDS/HIV w/CD4 < 200
people receiving high dose immunosupressive therapy or anti-tumor necrosis factor
S. aureus
gram + cocci in clusters catalase + coagulase + beta hemolytic small yellow colonies on blood agar ferments mannitol
S. aureus transmission
hands, sneezing, surgical wounds
foods: custards, potato salad, canned meats
S. aureus pathogenesis
adhesions, toxins, enzymes, surface binding proteins, capsule
tissue invasion and toxin mediation
S. aureus toxin mediated disease
food poising
toxic shock syndrome
scalded skin syndrome
staph aureus clinical manifestations
skin bacteremia endocarditis pericarditis osteromyelitis septic arthritis, infected prothetic joints penumonia
S. aureus skin maifestations
impetigo folliculitis furuncle abscess erysipelas cellulits mastitis necrotizing fasciitis wound infections
S. aureus endocarditis
roth spts
oslers nodes (ICs)
janeway lesions (septic emboli)
petichiae
S. aureus pneumonia
nosocomial pneumonia
salmon colored sputum
Staphylococcal food poisoning
S. aureus
enterotoxins A-E
2-6 hours after eating nausea, vomiting, diarrhea, ab pain
self limited
Toxic shock syndrom
S. aureus
TSST-1 (super Ag)
fever, erythoderma, hypotension, 3+organ systems, deequamation of palms and soles
scalded skin syndrome
S. aureus
exfoliative toxin A or B
S. aureus Tx
gastroenteritis is self limiting
Nafcillin/oxacillin
MRSA-vancomicin
Pneumocystis jirovecii
fungus
obligate extracellular parasite
silver stain
opportunistic infection in HIV patients w/CD4 count less then 200
PCP
fever
nonproductive cough
shortness of breath
CXR- patchy infiltrate, ground glass, lower lobe and periphery may be sparred
PCP Dx
silver staining cysts in bronchial alveolar lavage fluids or biopsy
PCP Tx
sulfamethaxazole/trimethoprim
or dapsone
PCP prophylaxis
when CD4 count <200
Histo
dimorphic fungus
facultative intracellular parasite
soil, caves, abandoned buildings w/bats or birds
Histo transmission
disruption of soil, cleaning attics, bridges, barns, tearing down old structures, spelunking
endemic to Mississippi and Ohio river valleys
Histo acute
most asymptomatic
several weeks after exposure fever, chills, fatigue, non-productive cough, anterior chest discomfort, myalgias
Histo chronic
progressive often fatal
elderly immunocompromised and COPD patients at risk
Histo x-ray acute
patchy lobar or multilobar infiltrate
Histo x-ray chronic
upper lobe infiltrates. multiple cavities, fibrosis of lower lobes (mimics TB)
Histo Tx
itraconazole Amphotericin B (IV)
Blasto
thermally dimorphic fungus
broad based budding yeast
associated w/soil and decaying vegetation, especially near rivers and lakes
blasto endemic
north central, south central, great lakes, and SE sea board
blasto acute
asymptomatic or thought to have community acquired pneumonia
fever, malaise, non-productive cough
skin lesions
Blasto acute CXR
lobar, multilobar, or nodular
Blasto chronic
fever night sweats fatigue weight loss cough hemoptysis dyspnea
Blasto chronic CXR
cavitary, nodular, fibrosis, mass like
Blasto Tx
all patients should be treated
Itraconazole if mild
amphotericin B if severe
Coccidiodes
dimorphic fungi
inhaled anthroconidia -> spherules -> internal septation -> endospores
endemic to SW desserts
coccidiodes clinical
most asymptomatic 5-11 days post exposure fever, weight loss, fatigue, dry cough, peluritic chest pain arthralgias erythema nodosum
coccidiodes CXR
pulmonary infiltrates
hilar adenopahty
peripneumonic effusion
pulmonar nodule-> cavitary
coccidiodes disseminated
immunocompromised
3rd trimester of pregnancy,
skin, joints, bones
coccidiodes Tx
itraconazole
amphortericin B
Paramyxoviruses traits
enveloped
helical neuclocapsid
negative sense ssRNA
paramyxoviruses
parainfluenza
measles
mumps
RSV
parainfluenza
person-person contact
most children exposed by elementary school
parainfluenza clinical
Coryza, rhinorrhea, pharyngitis w/o lymphadenopathy and low grade fever
symptoms for 3-5 days
CROUP
Croup
raspy barking cough w/indpiratory stridor, dyspnea, and respiratory distress
symptoms result from subglottic inflammation and edema
parainfluenza bronchiolitis or pneumonia
cough, rales, wheezing, hypoxia
cold
reinfection of adults w/parainfluenza typically caused cold symptoms in normal adults and kids
measles
rubeola highly contagious 3 Cs- cough, coryza, conjunctivits generalized maculopapular rash fever
measles contagious
4days before and after onset of rash
measles clincial
incubation 8-12 days
prodrome of fever, Cs, koplik spots
malaise, myalgia, HA
rash 2-6 days after catarrhal symptoms head-> trunk-> extremities
measles complications
diarrhea, otitis media, pneumonia
post infectious encephalomyelitis
subacute sclerosing panencephalitis
subacute sclerosing panencephalitis
degenerative demylinatng disease due to chronic infection
occurs years after acute measles infection and is universally fatal
measles Tx
supportive
prevention w/vaccine
Mumps clinical
parotitis
aseptic meningitis- common and usually mild
encephalitis rare and severe
orchitis
mumps Tx
supportive and prevention w/vaccine
RSV
epidemics late fall in souther states peaking in feb-march in colder climates
RSV clinical
infants
conjunctival injection, mucopurulent discharge, cough, low grade fever
otitis media
less common- wheezing, tachypnea, cyanosis
expiratory wheezing and rales
RSV CXR
hyperinflation and diffuse interstitial pneumonitis
RSV Tx
ribavarin
no vaccine
strongyloides stercoralis
endemic in warm climates
contact w/larvae in soil
enter circulation -> rupture in alveolar spaces-> coughed -> swallowed
stongyloides pulmonary
can be sever in immunocompromised
resembles ARDS w/acute onset of dyspnea, productive cough, and hemoptysis accompanied by fever, tachypnea, hypoxemia
stongyloides Tx
ivermectin
aspergillosis
ubiquitous organisms in foil, decaying matter, air
spore like conidia-> reach tissue forming invasice hyphae
basements, crawl spaces, bedding, humidifiers, ventilation ducts, potted plants, dust, condiments, marijuana
invasive aspergillosis
immunocompromised fever pulmonary inflitrates nodules wedge-shaped densities resembling infarcts sinusitis
aspergillosis extrapulmonary
CNS absesses, endophthalmitis, MI, GI, renal, osteomyelitis, endocarditis
aspergillosis Dx
BAL, needle aspiration, thoracoscopic biopsy, open lung biopsy
Tx aspergillosis
Antifungal- voriconazole or liposomal amphotericin B
reversal of immunosupression
surgical resection of infected lesions
aspergilloma
ball in cavity
debris in preformed cavity from TB, histo, or fibrocystic sarcoidosis
Tx- intraconazole or voriconazole
allergic bronchopulmonary aspergillosis (ABPA)
history of chronic asthma, or cystic fibrosis
airway obstruction, fever, eosinophillia, postive sputum cultures, mucous plugs containing Hyphae, brown flecks in sputum, upper lobe contraction,
elevated IgE
ABPA Tx
corticosteroids and itraconazole
Cryptococcosis
immunosupressed- HIV
meningitis is most common in clinical manifestation
pulmonary and other organ involvement can occur
cryptococcus neoformans
yeasts
environment and tissues
polysaccharide capsule is major virulence factor
cryptococcus CNS
meningioencephalitis HAs over several weeks nuchal rigidity lethargy personality changes confusion visual abnormalities nausea and vomiting
cryptococcus pulmonary
risk factors: COPD, corticosteroid use, solid organ transplant
fever, cough, dyspnea
treated w/antifungals
other organs affected by cryptococcus
skin prostate osteoarticular surfaces breast eye larynx
cryptococcus Dx
yeast grown in culture from CSF, blood, sputum, skin lesions, other body fluids
india ink stain
latex agglutination
cryptococcus CNS Tx non-aids
amphotericin B and flucytosine for 6 weeks
cryptococcus CNS Tx aids
amphortericin B and flucytososine for 2 wks followed by fluconazole
HACEK organisms
Heamophilus spp actinobacillus actinomycetemcomitans cardiobacterium hominis Eikenella corrodens Kingella
HACEK
5% of endocarditis
normal flora
common cause of endocarditis in IV drug users
difficult to diagnosis
CMV
member of herpes family double stranded DNA genome latent infections most clinical disease due to reactivation of latent infection in immunocompromised owl eye
CMV vertical spread
in utero during vaginal delivery
breast milk
CMV horizontal spread
saliva
genital
urine
CMV congenital and neonatal
microcephaly, intracerebral calcification, hepatosplenomegaly, and rash
mental retardation and hearing loss
mother w/primary infection during pregnancy
CMV immunocompetent
most asymptomatic
few w/mono like illness
CMV transplant recipients
fever, neutropenia, atypical lymphocytes, and hepatosplenomegaly
hepatits- transplanted liver
penumonia
colitis- diarrhea
CMV AIDS
CD4 <50
retinitis
colitis
CMV Tx
antivirals
