Microbiology review Flashcards
1-3 weeks after patients are exposed
Catarrhal phase- rhinorrhea, watery eyes, fever
paroxysmal phase- whoop like cough, blue faces after coughing spasm
complication for pneumonia
Bordetella pertussis
gram negative non motile capsulate rod facultative anaerobe severe bronchopneumonia cavitary lesions currant jelly sputum
CAP and HAP
alcoholic, lives on streets
lobar pneumonia
klebsiella pneumonia
gram negative grows on chocolate auger dplococci catalase and oxidase positive pneumonia especially in the elderly otitis media
moraxella catarrhalis
aerobic gram negative kidney shaped diplococci capsuele
grows on thayer-martin media, chocolate agar
oxidase positive
transmitted via resp droplets
seen in dorm, military barrics, outbreak of meningitis
commensal of the human upper resp tract
pneumonia
septicemia
septic arthritis, pericarditis, etc.
can lose limbs
Diagnosis:
Gram stain from CSF
CSF PCR
CSF culture
Treatment:
Penicillin
Prevention:
treat contacts with rifampin
neisseria meningitidis
if not treated–> systemic disease in 70-90%
morbidity- limb loss, hearing loss, long term neuro disability
aerobic gram negative rod
produces pyocyanin (blue green pigment on media)
sputum is bright fluorescent green
nosocomial pathogen - picked up in hospital or nursing home
seen in hospitalized patients, ventilators, nursing homes, hot tubs, swimming pools
most common cause of otitis externa
seen in puncture wounds in tennis shoes
exotoxins, endotoxins, pili, flagella, proteases (all the virulence factors!!)
treated with two or more broad spectrum antibiotics (cephalosporin, aminoglycosides)
(levofloxacin, gentamicin)
pseudomnas aeruginosa
gram negative obligate intracellular bacteria
macrophages are the principal host cell
diseases –> psittoacosis (bird fancier’s pneumonia), atypical pneumonia, febrile illness
Aerosolized bird secretions and dust
treatment: tetracyclines, macrolides, fluoroquinolones
prevention –> 30 day quarantine of birds before being sold in the US
chlamyodophila psittaci
common infection in children under 5
80% of adults are seropositive
atypical pneumonia*** -incubation of several weeks -nonproductive cough -preceded by congestion, sore throat, hoarseness headaches
exam- crackles and rhonci
normal white count
pnumonitis on CXR
prolonged course
Diagnosis:
serology
Treatment:
tetracyclines
macrolides
fluoroquinolones
chlamydophilia pneumoniae
Q fever
gram negative hosted in monocytes
incompletetly elimated after acute infection
endocarditis
lives in mammals, birds and ticks
major outbreaks have been related to sheep and goats and associated during lambing season
if a female develops this infection, she can get a chronic uterine infection which will prevent pregnancy (spontaneous abortions)
cerebral emboli, renal insufficiency, splenomegaly, hepatomegaly
diagnosis:
serology
treatment:
- doxycycline x2 weeks in acute cases
- doxycycine + hydroxychloroquine (increases phagosomal pH) for 18-36 months for endocarditis
coxiella burnetii
prolonged fever of unknown origin pneumonia hepatitis rash meningitis, encephalitis meningoencephalitis peripheral neuropathy pericarditis, myocarditis
Q fever
infectious zoonosis
small aerobic pleomorphic gram negative bacillus
rabbits, squirrels, muskrats
direct contact with infected animal tissue
ingestion of contaminated water or meat
Clinical manifestations:
- ulceroglandular- fever, swollen nodes, ulcer formation, sore throat, infiltrates
- glandular- fever, lymphadenopathy
- oculoglandular
- typhoidal- fever only
- oropharyngeal- painful exudative pharyngitis and tonsillitis, pharyngeal ulcers
- pnuemonic - dry cough, fever, pleural effusion, dyspnea, sore throat, hilar adenopathy, peribronchial infiltrates
francisella tularensis
spore forming gram positive non motile rod
aerobic or facultatively anaerobic
catalase positive
grows on sheep agar
zoonotic infection from goats, sheep, cattle, antelope, pigs, horses, etc.
Clinical manifestations inhalations: -mediastinal widening ** -pleural effusions -rapidly fatal if not treated with antibiotics and drain pleural effusion
bacillus anthracis
gram negative coccobacillus
microaeorphilic
non motile
non spore forming
prairie dogs are a common host
Clinical manifestations:
Bubonic= swollen, tender lymph nodes (buboes) at site of initial infection, fever, chills, body aches, headaches, untreated–> confusion, delirium
Septic = DIC, hypotension, renal failure and ARDS type picture
Pneumonic = highly fatal, often die within 24 hour period, fever, cough, chest discomfort, resp distress
yersinia pestis
treatments?
spirochete
silver staining or dark field microscopy
rodents, dogs, pigs, cattle and sheep
weil’s disease
pulmonary hemorrhage syndrome
Early phase:
-fever, myalgias, headaches, n/v, abdominal pain, diarrhea, cough, photophobia, tender muscles, conjunctival suffusion
Late phase Weils disease:
jaundice
acute hemorrhage, thrombocytopenia
Diagnosis:
-Agglutination test
leptospirosis
treat with doxycycline
gram negative*** pleomorphic rod
aerobic
grows on chocolate agar (factor X and factor V)
nasopharynx of adults and children
respiratory droplet transmission
Clinical:
Meningitis in children (not seen much anymore)
Epiglottitis - high fever, drooling, dysphagia, resp distress with stridor, sore throat, very rapid course, lateral neck film for diagnosis, thumbs sign
(make sure to distinguish from croup which has a steeple sign)
Pneumonia
bronchitis
acute sinusitis
haemophilus influenzae
treat with 3rd generation cephalosporin for meningitis
vaccinations
gram positive bacillus- club shaped
grows on throat and pharynx
non spore forming
transmission- bacterium or phage via respiratory droplets
sore throat, malaise
thick tonsillar exudate (grayish membrane that is tightly adherent and bleeds on attempted removal)
cervical adenopathy (Bull neck) stridor extension of membrane can lead to airway obstruction myocarditis
Corynebacterium diptheria
treat with erythromycin
antitoxin
vaccination
