Lecture 18 11/9/23 Flashcards
What are the general characteristics of Chlamydia spp.?
-obligate intracellular
-parasites of epithelial cells
-susceptible to tetracycline
-dimorphic life cycle
-energy parasites/consume host ATP
Which Chlamydia spp. is known for causing zoonotic infections?
C. psittaci
Which Chlamydia spp. cause disease in humans?
-C. trachomatis (human chlamydiosis
-C. pneumonia
What are the two life cycle stages of Chlamydia spp.?
-intracellular replicating form
-extracellular non-replicating form
What are the characteristics of elementary bodies?
-infectious stage of Chlamydia spp.
-can survive outside the host
What are the characteristics of C. psittaci?
-causes avian chlamydiosis
-BSL-3 pathogen
-zoonotic
-reportable
What is the pathogenesis of C. psittaci?
-elementary bodies shed in carriers’ feces
-replicate in epithelial and phagocytic cells after inhalation
-cause septicemic, multi-organ infection
Which lesions are associated with C. psittaci?
basophilic intracytoplasmic bacterial inclusions
How are Chlamydia spp. diagnosed?
-microscopic detection
-culture in embryonated eggs, tissue, or animals
-serology
-PCR
How are Chlamydia sp. treated?
tetracycline
How are Chlamydia sp. controlled?
isolation and quarantine procedures
What disease manifestations are caused by Chlamydia abortus in ruminants?
-placentitis
-abortion
What disease manifestations are caused by Chlamydia pecorum?
-polyarthritis in lambs and calves
-sporadic bovine encephalomyelitis in young cattle
What are the characteristics of Chlamydia felis?
-causes feline pneumonitis
-common signs are conjunctivitis and rhinitis
What are the characteristics of Coxiella burnetii?
-causes Q fever
-obligate intracellular
-causes subclinical infection, abortion, and placentitis
-highly persistent in environment
-has resistant endospore-like form
-highly zoonotic
How is Coxiella burnetii diagnosed?
-serology
-direct demonstration
-culture in cell lines
-PCR
Which antimicrobials can be used to treat C. burnetii?
-tetracycline
-fluoroquinolones
How can C. burnetii be controlled and prevented?
-hygiene
-education
-early diagnosis
-vaccination
Which order Rickettsiales members are pathogens of dogs and cats?
-Ehrlichia canis
-E. chaffeensis
-E. ewingii
-Anaplasma phagocytophilum
-A. platys
-Neorickettsia helmintoeca
-N. risticii
-Rickettsia rickettsii
What are the characteristics of Rickettsia?
-arthropod-transmitted
-parasites of blood cells or endothelial cells
-gram-neg. coccobacilli
-cause persistent infections
-obligate intracellular
-rodents/small mammals are reservoirs
What are the two groups of Rickettsia?
-typhus group
-spotted fever group
Which spotted fever group Rickettsia spp. is of most importance?
R. rickettsii
What are the characteristics of Rickettsia rickettsii infection?
-causes rocky mountain spotted fever
-organism invades and replicates in endothelial cells of smaller blood vessels
-causes progressive necrotizing vasculitis
What are the characteristics of Rickettsia felis?
-emerging infection in humans
-transmitted by cat fleas
-causes flea-borne spotted fever
How can Rickettsia spp. be diagnosed?
-direct detection
-PCR
-serology
Which antibiotics can be used against Rickettsia sp.?
-tetracycline
-doxycycline
-chloramphenicol
-enrofloxacin
What are the characteristics of Piscirickettsia salmonis?
-causes piscirickettsiosis in farmed fish
-antibiotic treatment commonly fails
-vaccines available
What are the general characteristics of Anaplasmataceae?
-parasites of hematopoetic cells of vertebrates
-transmitted by invertebrate hosts and vectors
-can be zoonotic
Which genuses of Anaplasmataceae are of importance?
-Anaplasma
-Ehrlichia
-Neorickettsia
What are the characteristics of Anaplasma phagocytophilum?
-transmitted by Ixodes ticks
-causes canine granulocytic ehrlichiosis
-found in host neutrophils
What clinical sign of A. phagocytophilum is seen in dogs?
necrotizing small vessel vasculitis
What clinical signs of A. phagocytophilum is seen in horses?
-limb edema
-icterus
-ataxia
How is A. phagocytophilum diagnosed?
-direct staining/demonstration
-PCR
-SNAP test
Which antimicrobial can be used to treat A. phagocytophilum?
tetracycline
What are the characteristics of Anaplasma platys?
-causes infectious cyclic thrombocytopenia
-infects platelets
-often asymptomatic
How is A. platys diagnosed?
-direct detection
-FA
-PCR
How is A. platys treated?
doxycycline
What are the characteristics of Anaplasma marginale?
-causes anaplasmosis in ruminants
-infects erythrocytes
-causes icterus/jaundice
-calves are more resistant than adults
How can A. marginale be diagnosed?
-direct stain
-FA
-PCR
-ELISA
-serology
How is A. marginale treated?
tetracycline
What are the characteristics of Ehrlichia canis?
-causes canine monocytic ehrlichiosis
-infects monocytes and forms morulae
-transmitted by R. sanguineus (brown dog tick)
-acute and chronic phases
-can cause pancytopenia in severe forms
How is E. canis diagnosed?
-IFA
-snap test
-PCR
Which antimicrobial is used to treat E. canis?
doxycycline
Which Ehrlichia species are spread by A. americanum ticks, and what diseases do they cause?
-E. ewingii: granulocytic ehrlichiosis
-E. chaffeensis: human monocytic ehrlichiosis
What are the characteristics of Ehrlichia ruminantium?
-causes heart water disease
-foreign and reportable
-bacteria replicates in macrophages and endothelial cells
-vectored by ticks
How is E. ruminantium diagnosed?
demonstration of colonies in the cytoplasm of capillary endothelial cells
Which antimicrobial can be used to treat E. ruminantium?
tetracycline
What are the characteristics of Neorickettsia risticii?
-causes potomac horse fever/equine monocytic ehrlichiosis
-infects enterocytes and monocytes
-leads to hemorrhagic enterocolitis
How is N. risticii diagnosed?
-based on clinical signs
-PCR
-direct detection
How is N. risticii treated and prevented?
-early diagnosis
-tetracycline
-vaccination
What are the characteristics of Neorickettsia helminthoeca?
-causes salmon poisoning in dogs
-dogs eat tissue infected with flukes
-infects monocytes and macrophages
-causes lesions in intestines associated with the lymphoid tissues
How is N. helminthoeca diagnosed?
-detection of fluke eggs
-PCR
How is N. helminthoeca treated?
-tetracycline
-praziquantel
