Leishmania/Mycobacteria Flashcards
Geographically, where will you find Lutzomyia
New World
Geographically, where will you find Phlebotomus
Old World
Vector for Leishmania
Sandflies
Time of day that sandflies feed
Crepuscular, nocturnal
Main reservoir of cutaneous and mucocutaneous Leishmania
Rodents, wild animals
USA states with endemic Leishmania
-Texas (reportable)
-Oklahoma
-Alabama
-Michigan
-Ohio
Species that get Leishmania infantum infections
Dogs
Cats
Humans (Braziliensis, donovani)
In which cell does Leishmania live
Macrophages
When Leishmania is in the host’s body, what form is it in
Amastigote, non-flagellate
When Leishmania is in the foregut and mouthparts of Sandflies (infectious state), which form is it in
Promastigote (flagellated)
Where in the dog’s body would you find Leishmania
Bone marrow, lymph nodes, skin, spleen, liver
How can a host develop Leishmania WITHOUT a sandfly vector
*Vertical transmission
*Sexual transmission (epididymus, glans penis, testis, prepuce)
*Blood transfusions
T or F: Most dogs that contract Leishmania are clinical
False. Many are subclinical
Age of Leishmania infection
Bimodal
2-4 years old (younger)
7+ years old (older)
Breeds predisposed to Leishmania
*Boxer
*GSD
*Rottweiler
*Cocker spaniel
Immune response type that makes you RESISTANT to Leishmania infection
Th1
Immune response type that makes you SUSCEPTIBLE to Leishmania infection
Th2
Which cell is important for control of Leishmania infections
Macrophages
(which Leish likes to invade!)
Which cytokines are crucial for inducing macrophage anti-leishmanial activity
IFN-g
IL-2
TNFa
(Th1)
Which cells can lyse infected bacrophages
Cytotoxic T cells
If dogs have cutaneous lesions, they probably also have ________
Visceral lesions
Ocular lesions of Leishmania
Conjunctivitis
Anterior uveitis
Blepharitis
KCS
Most common cutaneous lesion of Leishmania
*Exfoliative dermatitis
Prominent on pinnae, head, extremities, pressure points
Nasodigital hyperkeratosis, periocular alopecia (lunettes)
-Can also have ulcerative dermatitis on paws, pinnae, MC junctions
What organs can enlarge with Leishmania
Lymph nodes
Spleen
+weight loss, muscle atrophy despite strong appetite
Which disease 2’ to Leishmania is the typical cause of death
CKD (PUPD)
Occurs 2’ circulating immune complexes, vasculitis
Clinical signs from circulating immune complexes 2’ Leishmania
PUPD -> Renal failure
Vasculitis
Uveitis
Polyarthritis
Labwork findings with Leishmania
-Elevated liver enzymes
-Renal values
-Proteinuria
T or F: PCR of peripheral blood is likely to diagnose Leishmania
FALSE. Rarely detected in peripheral blood.
Antibody tests are better in peripheral blood. High antibody levels are associated with high tissue parasite loads
What is the most sensitive test to diagnose Leishmania? Where should you collect your sample from
PCR for Leishmania DNA
Bone Marrow/Lymph node»_space; Skin > Conjunctiva > Whole blood/buffy coat
Histopath stain to find Leishmania amastigotes
Giemsa stain
Which adnexa is often affected by Leishmania, which causes the exfoliative dermatitis
Sebaceous glands
T or F: Leishmania is often curable with Meglumine antimoniate and allopurinol
False. Relapses are common
Main drug to treat Leishmania? Side effects?
Meglumine antimoniate (SC)
AEs: Nephrotoxic. Cellulitis at injection site
MOA of allopurinol in Leishmania treatment
Hypothanine that is metabolized by Leishmania to produce an inosine analogue
Inosine analog is incorporated into Leishmania RNA –> inhibits parasite multiplication
Alternative treatment to meglumine antimoniate for Leishmania? MOA?
Miltefosine
Directly toxic on Leishmania. Use WITH allopurinol
Prevention of Leishmania
*Inside at dusk/dawn
*Commercial vaccine (Brazil, Europe)
*Permethrin, Imidacloprid, Deltamethrin topicals
Most common species of CUTANEOUS Leishmania
*L braziliensis
*L peruviana
Can have coninfections with L infantum
Breed with canine VISCERAL leishmaniosis in USA
Foxhounds! (Starting in NY, but found all over N America)
Best stain for Actinomyces on histopath
Giemsa
Gram
Silver
(NEGATIVE for acid fast/ Fite Faraco_
T or F: FIV/FeLV is a predisposing factor for actinomyces
FALSE.
Actinomyces are usually healthy individuals. Nocardia is immunosuppressed ones
Predisposed signalment for Nocardia infection
Male, immunocompromised
Where is Nocardia found? Where is actinomyces found?
Nocardia: soil
Actinomyces: commensal
Are atypical mycobacteria rapid or slow growing
Rapid
Most common clinical lesion associated with atypical mycobacteria
Panniculitis
(esp cats»_space; dogs)
What medication is used to treat Nocardia? AE of long term use?
TMS
Myelosuppression
How would you identify mycobacteria on cytology
Negatively staining rods within macrophages (or free-floating)
Will you see Mycobacteria on H&E histopath?
No. Not visible within macrophages on histo
Need to use acid fast
Which species causing feline leprosy causes periocular lesions only, with a good prognosis
Mycobacteria tarwinese
Which species causing feline leprosy causes more generalized lesions that ulcerate in young animals, with a worse prognosis
Mycobacteria lepraiefelis
Difference between feline leprosy and atypical mycobacteria
Feline leprosy: dermal nodules, slow growing
Atypical: SC nodules, inguinal pad, fast growing
Reservoir for Mycobacteria microti
Rodents
Reservoir for Mycobacteria bovis
Cattle, badgers
Route of transmission for slow growing Mycobacteria (microti, bovis)
Bites
Signalment of cat with Mycobacterium avium complex (MAC)
Immunosuppressed
Breeds: Siamese, Abyssinian
Most common Leishmania species in dogs
Leishmania infantum
