Infectious Diseases - Sykes & Ettinger Flashcards
Morula in a mononuclear cell –> Ehrlichia canis or chaffeensis, Neorickettsia risticii
Organism? Size? Type? Magnification?
Blastomyces dermatitidis
5-20 microns (big)
Extracellular budding yeast
20-50x
Organism? Size? Form in the body? Magnification?
Cryptococcus neoformans-gatii complex
3.5-7 microns (small)
Extracellular yeast
100x
Organism? Size? Form in the body? Magnification?
Coccidiodes immitis or posadacii
20-200 microns (big)
Extracellular spherules containing numerous endospores
40x
Organism? Size? Form in the body? Magnification?
Histoplasma capsulatum
2-4 microns
Intracellular yeast in mononuclear phagocytes
100x
Organism? Size? Form in the body? Magnification?
Sporothrix schenckii
2-3 x 3-6 microns (ovoid)
Intracellular yeast in mononuclear phagocytes
100x
Possible organisms?
Morula in a neutrophil –> Ehrlichia ewingii, Anaplasma phagocytophilum
Organism?
Canine distemper virus
Inclusions in lymphocytes, neutrophils, RBCs
What vaccines are considered core vaccines in puppies?
What is the recommended vaccination schedule?
Parvo, distemper, adenovirus, rabies
every 3-4 weeks starting at 8-9 weeks of age
last dose given at > 16 weeks
What vaccines are considered core vaccines in kittens?
Recommended vaccination schedule?
Panleukopenia, feline herpesvirus-1, feline calicivirus
Every 3-4 weeks starting at 8-9 weeks of age, last given at > 16 weeks
What three enteric zoonoses are immediately infectious after shedding in animal feces?
Campylobacter, Cryptosporidium, Giardia
What zoonotic infections are associated with visceral larva migrans in humans?
Toxocara cati, Toxocara canis (roundworms), Baylisascaris procyonis
Class and mechanism of action of fenbendazole?
Susceptible organisms?
Benzimidazole class
Bind beta tubulin –> inhibition of microtubule formation & cell division
Inhibition of glucose uptake by protozoa, helminths
Organisms: Giardia, Taenia tapeworms
Roundworms (Toxocara canis & cati, Toxascaris leonina)
Hookworms (Ancylostoma caninum, tubaeforme, braziliense, Uncinaria stenocephala)
Whipworms (Trichuris vulpis)
Mechanism of anti-protozoal effect of nitroimidazoles?
Drugs in the nitroimidazole class?
Susceptible parasites?
Mechanism: metabolized by protozoal nitroreductase to reactive oxygen species
Drugs: metronidazole, ronidazole, benznidazole
Metro –> Giardia protozoa
Ronidazole –> Tritrichomonas blagburni (prev foetus)
Benznidazole –> T. cruzi
What bacterial genus is inherently resistant to TMS?
Enterococcus spp
Mechanism of action of pyrimethamine?
What other antimicrobial works similarly?
Susceptible organisms?
Dihydrofolate reductase inhibition –> lack of folate synthesis
Sulfa drugs also inhibit dihydrofolate reductase, but are more specific to bacterial forms
Organisms: Toxo, Neospora, Isospora (intestinal coccidiosis)
Hepatozoon americanum (in combo with TMS and clinda)
Mechanism of action of atovaquone?
Susceptible organisms?
Inhibition of cytochrome bc1 complex –> inhibition of mitochondrial electron transport
Babesia gibsoni and condradae, cytauxzoon felis (in combination with azithromycin)
Mechanism of action of imidocarb diproprionate?
Susceptible organisms?
Inhibition of protozoal DNA synthesis
Babesia canis, Hepatozoon canis (not described in the US)
Mechanism of action of amphotericin B?
Azole drugs?
Terbinafine?
Which drugs have good CNS penetration? Concentration in the urine?
Amphotericin B: irreversible binding of sterols in fungal cell membranes, forming pores/channels with leakage of ions; also activates macrophages & enhances macrophage killing mechanisms
Azoles: Inhibition of sterol 14-alpha demethylase –> inhibit ergosterol synthesis, cause buildup of 14alpha methylsterols which disrupt fungal cell membrane
Terbinafine: inhibits squalene epoxidase -> decreased lanosterol & ergosterol synthesis & buildup of toxic squalene
Itraconazole. fluconazole have good CNS penetration; flu has good concentration in urine
Recommended treatment for canine Leishmaniasis?
What drug is NOT recommended?
Antimony: converted from pentavalent to toxic trivalent form & interferes with DNA synthesis in the parasite
Allopurinol: purine analog; metabolites incorporated into RNA –> impaired protein synthesis USE IN COMBO W/ ANTIMONIAL COMPOUND
Amphotericin B has activity, but not recommended due to increasing resistance
Sensitivity and specificity of the SNAP 4Dx ELISA for ehrlichiosis, and anaplasmosis?
Ehrlichia: 97% sensitive, 100% specific (doesn’t do species) (Ettinger says high 90s for both species for sens & spec)
Anaplasma: 92% sensitive, 100% specific (doesn’t do species)
Most common viral pathogen associated with CIRD? 2nd most? Characteristics?
Canine parainfluenza virus: enveloped ssRNA Paramyxoviridae
-often co-infected w/ Bordetella (G- aerobic coccobacillus)
Canine respiratory coronavirus: enveloped ssRNA Coronaviridae
