obligate intracellular bacteria Flashcards
mycoplasma
smallest free living prokaryotic microorganisms, facultative anaerobes
- lack cell walls (gram staining not useful)
mycoplasma pneumoniae transmission
respiratory droplets (causes lower resp tract infection)
diagnosis and treatment of mycoplasma pneumoniae
IgM-specific antibody titer is diagnostic
mycoplasma mycoides
highly contagious disease called contagious bovine pleuropneumonia (transmission by aerosols with a high mortality rate)
sign of mycoplasma mycoides postpartum
pneumonic lungs will show marbling
cell membrane of mycoplasma species
sterol- containing lipid bilayer
where do chlamydiaceae grow?
cytoplasmic vacuoles in a limited number of host cell types
are chlamydiaceae gram - or +
negative
chlamydiae possess ______ and synthesize their own _______
ribosomes, protein
reproductive cycle of chlamydiaceae
1) the elementary body is taken up by phagocytosis into susceptible host cells
2) the elementary particle reorganizes into a larger, noninfectious reticulate body
3) the reticulate body divides repeatedly by binary fission, forming inclusion bodies
4) after 48 hours, multiplication ceases and reticulate bodies condense, becoming new, infectious elementary bodies
5) elementary bodies are then released from the cell by cytolysis, ending in host cell death
chlamydia trachomatis
infections of the conjuctiva or genital tract which vary depending on the biovar involved
trachoma
progressive conjunctivitis with inflammation and scarring leading to blindness
genital biovars
most common form of sexually transmitted urethritis, cervicitis, and salpingitis
lymphogranuloma venereum biovars cause
localized, ulcerative genital lesions with spread to regional lymph nodes
trachoma
spread by direct contact with the eye, nose, throat secretions from affected individuals, or contact with fomites
neonatal conjunctivitis
swelling of eyelids, hyperemia and purulent discharge beginning 2-30 days after birth
infant pneumonia
rhinitis 2-3 wks after birth and a distinctive staccato cough, no feverc
community acquired respiratory infection is caused by
chlamydia pneumoniae
community acquired respiratory infection causes
pharyngitis, laryngitis, bronchitis, sinusitis, or interstitial pneumonia
psittacosis is caused by
chlamydia psittaci
how is psittacosis transmitted
through inhalation of contaminated dust containing bird feces
what does psittacosis affect
lower resp tract, causing fever, dry cough, flu like symptoms & patchy pulmonary infiltration
rickettsiaceae
obligate intracellular gram- negative bacilli
- cell walls contain peptidoglycan
only grow inside living host cells
rickettsiaceae causes
systemic diseases that are mainly arthropod borne in humans and animals
rocky mountain spotted fever organism
rickettsiaceae rickettsii
rocky mountain spotted fever vector
tick
rocky mountain spotted fever clinical features
inward- spreading macular rash (abrupt onset)
epidemic typhus orgnaism
rickettsiaceae prowazekii
epidemic typhus vector
lice (defecate while feeding and they also die from the infection)
epidemic typhus clinical features
arthralgia; outward spreading macular rash
- abrupt onset
endemic typhus organism
rickettsiaceae typhi
endemic typhus vector
flea (rat flea xenopsylla cheopsis)
endemic typhus clinical features
gradual onset of fever, headache, myalgia, and cough; maculopapular rash on trunk
rickettsial pox organism
rickettsiaceae akari
rickettsial pox vector
mites
rickettsial pox clinical features
generalized papulovesicular rash accompanied by sloughing
- abrupt onset
human monocytic ehrlichiosis (HME) caused by
ehrlichia chaffeensis
human monocytic ehrlichiosis (HME) vector
lone star tick
human monocytic ehrlichiosis (HME) clinical signs
acute fever, myalgia, leukocytopenia and thrombocytopenia
human granulocytic anaplasmosis (HGA) caused by
anaplasma phagocytophilum
human granulocytic anaplasmosis (HGA) vector
deer and dog tick
human granulocytic anaplasmosis (HGA) clinical signs
more severe fever, myalgia, leukocytopenia and thrombocytopenia
Q fever organism
coxiella burnetti
coxiella burnetti gram stain
poor. better stained with giemsa or gimenez stains. gram negative
q fever
zoonotic from cattle, sheep, and goat - airborne transmission to farm workers, vets