bacteria that live in blood cells Flashcards
(30 cards)
think of what when you see pale pets AND agglutination
hemoplasma when you see pale pets. logically cause anemia
clinical findings of feline hemoplasmosis
acute:
- fever
- pale mm’s
- lethargy, depression
- spenomegaly
- icterus
Chronic
- fever
- recurrent/relapsing anemia
- weight loss
feline hemoplasmosis
species:
- mycoplasma haemofelis (most pathogenic)
- M. haeuminutum (not yet officially accepted as its own species))
Transmission:
- direct contact
- fleas?
- other vectors
laboratory findings of feline hemoplasmosis
regenerative anemia
hyperbilirubinemia
neutrophilia
monocytosis
lymphocytosis
+/- coombs test
+/- organism
canine hemoplasmosis
haemobartonella canis
mycoplasma haemocanis
m. haemotoparvum
transmitted by rhipicephalus sanguineus (the brown dog tick)
clinical disease:
- in immune suppressed dogs causes hemolytic anemia
- can be a cofactor making many other agents more pathogenic
hemoplasma diagnosis
has not been cultured
- resides on surface of RBC’s
NO current antibody tests
cytology
- false+ common: stain precipitates
- false - common: rapid changes in bacteremia, can fall off RBC’s in EDTA
PCR
- more sensitive and specific than cytology
hemoplasma treatment - small animals
has not been cultured so no susceptibility testing
- doxycycline
- fluoroquinolones
prevention and control
- prevent cat fights
- control fleas and ticks
The Rickettsiales
minute obligate intracellular parasites of eukaryotic hosts
anaplasma and ehrlichia
formerly all considered Ehrlichia
lack of cell walls and LPS bio biosynthetic pathways
transmitted by ticks
form morulae within cells
can be cultured in cells but not useful clinically
IS DIAGNOSED BY PCR
anaplasma and ehrlicha vectors
ehrlichia canis
- vectors rhipicephalus sanguineus - BROWN DOG TICK
anaplasma phagocytophilum
- vector - ixodes spp. ticks (DEER TICKS)
Anaplasma and Ehrlichia cytology
anaplasma: survives in PMNs (neutrophils)
ehrlichia: lymphocytes and monocytes
Rhipicephalus ticks can vector 6 significant disease agents
Ehrlichia canis
Anaplasma platys
Hepatozoon canis
Babesia vogeli
Mycoplasma hemocanis
Ehrlichia canis clinical picture
Clinical signs
- Fever
- lethargy
- anorexia
- lymphadenopathy
- epistaxis (from vasculitis)
Clinical Pathology
- thrombocytopenia
- proteinuria (immune complex in kidneys)
most likely tickborne disease to cause
- pancytopenia (wipes out bone marrow)
- monoclonal gammopathy
- only 25% of dog owners noticed a tick on their dog
Ehrlichiosis diagnosis
morulae detection (rare)
- Morulae = organism in vacuoles
PCR
Antibody detection
- IFA
- In house ELISA (SNAP tests; IDEXX, biogal, others)
- service labs (antech IDEXX)
Ehrlichia ewingii
can cause disease in dogs or humans
- granulocytic ehrlichiosis
- acute fever, polyarthritis
Transmitted by the tick Amblyomma americanum (lone star tick)
Diagnosis:
PCR (acute), serology (subacute, chronic)
Treatment:
- doxycycline 14-28 days (long course)
Pevention:
- tick control
diagnostic timelines
right before 4 weeks PCR is food, then they start to amount immune response and antibodies and not good
but then can use serology a little after 4 weeks
so right at 4 weeks… could be negative. CAN BE DIFFICULT
PCR detects Ehrlichia DNA
GP36 assay detects E. canis GP36 protein
IFA and SNAP detect antibodies
Ehrlichiosis - okay to make a presumptive diagnosis IF
seropositive/PCR positive
appropriate clinical signs
exclusion of other causes
response to anti-rickettsial drugs
Feline Ehrlichiosis
not very common but can happen
documented in Africa, France, Turkey, and the US
- transmitted by Ticks
exact Ehrlichia species that causes it is not yet identified
treating ehrlichiosis
doxycycline 10mg/kg PO q 12 hours
- 14-28 days
imidocarb diproprionate 5.5 mg/kg IM
- inhibits parasite electron transport chain (cytochrome enzyme)
- twice, 14 days apart
duration - 14-28 days
- until platelets and globulins normalize
prevention and control
- acaracides - kill ticks
anaplasmosis
caused by various Anaplasma spp.
transmitted by Ixodes and Rhipacephalus ticks
Anaplasma Platys
Predominantly affects dogs
thrombocytotropic anaplasmosis - lives in platelets
acute fever, polyarthritis, thrombocytopenia
no known chronic phase
transmitted by thipicephalus sanguineus
- mostly diagnosed in souther US by PCR, snap exists but its unreliable false negatives a lot
tx: doxy 14-28 days
control and prevention: tick control
Anaplasma phagocytophilum
Affects dogs, cats, horses, cattle, people
- granulocutotropic anaplasmosis
- acute fever, polyarthritis, thrombocytopenia
- no known chronic phase
transmitted by Ixodes spp. (deer ticks)
Diagnosis
- see morulas more often than Ehrlichia
- PCR, serology both useful
Treatment - doxycycline 14-28 days
- no need to follow titers or PCR, responds well to treatment
- control/prevention - tick control
Bartonella spp. Bartonellosis
NOT a rickettsiales
fastidious gram - coccobacilli or short curved intracellular rods
slow growing
- up to 45 days
- this is why Koch’s postulates for this disease were missed for years
is currently most commonly identified by genetics
cat scratch fever
Bartonella spp. are often associated with cats
B. henselae
B. clarridgeaie
B. koehlerae
B. quintana
can cause significant illness in humans, cats, and dogs
the cat flea is the vector for henslae, clarrideaiem and koehlerae
part of life cycle requires living in an RBC
-intraerythrocytic stage results in passage in flea frass
organism survive in fleas for at least 9days
