bacteria3 Flashcards
intracellular vector-borne diseases
Rickettsial disease and Erlichiosis
cells infected by Rickettsia (why rash); what does this cause?
endothelial cells; perivascular lymphocytic infiltrate
where rickettsia multiply
small vessel endothelia
severe manifestations of rickettsial infection due primarily to this
vascular leakage
symptoms you will see due to vasculitis of important arterioles/capillaries
encephalitis, pneumonitis, rash, N/V, kidney failure
Rickettsia intra or extracellular?
intracellular
mediates immune response responsible for much of tissue damage seen in Rickettsial infection
cytotoxic T cells
clinical presentation of Rickettsia patients
fever, rash, CNS symptoms
treatment for Rickettsia
doxycycline
severe presentation of Rickettsia
hypovolemic shock, DIC, pulmonary edema
DDx for Rickettsial infection
Rickettsial disease, Meningococcemia, Rubeola, Rubella, Erlichiosis
spreads epidemic typhus (Rickettsial disease)
lice
organism that causes epidemic typhus (spread by head lice)
R. prowazekii
what epidemic typhus begins with clinically; what CNS symptoms can then manifest?
centrifugal rash; apathy, dullness, stupor, coma
mild clinical findings for epidemic typhus
rash and small hemorrhages
more severe clinical finding in epidemic typhus
gangrene (tips of fingers, nose, earlobes, scrotum, penis and vulva)
incubation period for RMSF
7 days
vector for RMSF
tick
length of time for high fever in RMSF; when does rash appear?
2-3 weeks; day 6
major cause of death in RMSF
noncardiogenic pulmonary edema
primary vector for RMSF in east of country
american dog tick
3 places that lyme disease disseminates; what is most common cause of death?
heart, joints, brain; heart
most common vector for Lyme disease (animal to human)
tick
spirochete that causes Lyme disease
Borrelia burgdorferi
areas in country where Lyme disease most common
WI, MN, east coast
receptor for LPS on macrophages…important in Lyme disease immune response (causes most pathology)
TLR2
skin rash (vasodilation) w/ dense perivascular inflammatory infiltrates of mononuclear leukocytes
primary Lyme disease
bulls eye lesion cause by this organism
B. burgdorferi
time frame for secondary Lyme disease to develop
weeks to months
symptoms of secondary lyme disease
joint disease, cardiac arrhythmias, meningitis w/ CN involvement, muscle pain
time frame for tertiary Lyme disease to develop
years
symptoms of Pasteurella multocida due to cat bite/scratch (most common)…rapidly developing under 24 hours
cellulitis, abscesses, sepsis
antibiotic used for cat bite/scratches (*all should be treated*)
Augmentin
causes cat scratch disease (associated with kittens and fleas)
Bartonella henselae
symptom of cat scratch disease
localized lymphadenopathy
most widespread zoonotic disease in world
Leptospirosis
where is Leptospira interrogans excreted from in canines?
urine
what does Leptospirosis resemble (acute, self-limited, febrile w/ biphasic irritation, conjunctival irritation, hyperemia)
viral meningitis
virus from “pocket pets”….3 patients received organs and later died with this in 2005…found in pet rodents; exposed thru urine, droppings, saliva, or nesting material
Lymphocytic Choriomeningitis Virus
inhalation of dust-borne contaminated excretia from birds…
ornithosis
these animals commonly carry salmonella
reptiles, turtles
very young, very old, immunocompromised, pregnant women should not be exposed to these kind of pets
reptiles and pocket pets
this bacteria infection comes from rabbits, causes granulomatous inflammation
Tularemia
animals associated with Anthrax (Bacillus anthracis)
sheep and goats
cutaneous sign of Anthrax
small hemorrhagic pustule (develops to black eschar), painful lymphadenitis
pathological mechanism of Anthrax
antiphagocytic, edema and cytotoxic factors, leukopenia (destroys PMNs), DIC and death
presentation of inhalation of Anthrax
severe pneumonia
treatment for Anthrax infection
penicillin, doxy (also a vaccine)
stain that is retained in acid fast mycobacterium after washed with acid solvents
carbolfuschin
M. tuberculosis is associated with these risk factors
elderly, AIDS, alcoholism
histological hallmark of M. tuberculosis
caseating granuloma
type of hypersensitivity that M. tuberculosis induces (cytotoxic T cell response)
IV
makes up granuloma (tubercle) of M. tuberculosis
epithelioid cells, Langhans multinucleate giant cells, collar of fibroblasts, lymphocytes
cytokines that are important in granuloma formation due to specific T cell mediated response
IFN-g and TNF
lacking previous contact with TB…go to terminal bronchials and forms granuloma
primary/latent TB
single granuloma of lower part of upper lobes with mediastinal lymph nodes having caseating granulomas
Ghon focus
where Gohn focus most common in latent TB
lower part upper lobe or upper of lower
makes up Gohn focus
primary lung lesion plus caseating necrosis in mediastinal LN
where does secondary TB spread? why?
apical lobes; higher oxygen tension
coalescing granulomas…lost necrotic center because it has eroded into airway (looks like hole)
cavitary lesions
characteristic findings on Xray for TB diagnosis
cavitary lesions, calcification of lymph nodes
test that measures amount of interferon production released by MP exposed to TB
Quanti-feron
areas of body affected by Leprosy (mycobacterium leprae)….coolest parts of body
skin and nerves
progressive and contagious form of Leprosy
lepromatous
spirochete that causes syphilis…*3 stages* similar to Lyme disease
Treponema pallidum
painless ulcer…primary lesion of syphilis
chancre
in URT/meningitis infections…this activates endothelial cells and MP and causes vascular leakage –> can lead to DIC
LPS
URT, gram positive, diplococcus that can cause sepsis and meningitis
Pneumococcus
URT, gram negative diplococcus that can cause DIC, sepsis and meningitis
N meningitidis and N gonorrhea
URT, gram negative diplococcus that can cause septic arthritis
N gonorrhea
URT, gram negative diplococcus that can cause sepsis and meningitis
H influenzae B
in capsule of bacteria…triggers systemic inflammation –> sepsis/DIC
LPS or PspC
receptors that LPS interacts with to induce systemic cytokine secretion and endothelial cell activation
TLR
characterized by systemic activation of coagulation by bacteria –> systemic microthrombi –> hemorrhage (after coag factors used)
DIC
gonnococci only have this in cell wall…why rarely cause sepsis/DIC/meningitis
LOS
Strep pneumoniae is major cause of these diseases
URI, lobar pneumonia, meningitis
N meningitidis is sensitive to this antibiotic
penicillin
Type B haemophilus has this kind of toxin characteristic –> can lead to DIC
endotoxin
Haemophilus infection that could result in endocarditis (usually normal flora)
H parainfluenzae
Haemophilus that causes chancroid
H ducreyi
must conjugate encapsulated bacteria vaccines (H influenzae) because infants cannot make effective antibodies against this
capsule polysaccharides
