Lecture 12 - Actinobacteria II Flashcards
What are the general characteristics of arcanobacterium?
Pleomorphic, non-spore forming
What cell morphology can occur with acracnobacterium?
Coccobacillus + Rod + Club-shaped
What is the oxygen preference of arcanobacterium?
Facultative anaerobes + aerobes
Capnophiles
What is the living style of arcanobacterium?
Commensal - mucous membranes
What does A. pyogenes do on blood agar?
Beta-hemolysis
What is the cell morphology of A. pyogenes?
Coccobacillary to short rods
Club-shaped in young cultures
What is the oxygen preference of A. pyogenes?
Facultative anarobe
Capnophilic
Where does A. pyogenes normally occur?
Upper respiratory + Urogenital + GI tract
Of ruminant, swine, etc.
What is the common way in which A. pyogenes infections occur?
Traumatic inoculation + Secondary infection
How does host to host transmission of A. Pyogenes occur?
Mastitis in cows
What type of mastitis is A. pyogenes known for causing?
Summer mastitis
What are the virulence factors of A. pyogenes?
Pyolysin O + Neuraminidase
What does pyolysin O do?
Cytotoxic to macrophages + NEU + RBC’s
What does Neuraminidase do?
Bind to host cells and ECM
What does A. pyogenes act as a synergistic pathogen for?
F. necrophorum
What does A. pyogenes tend to do in the body?
Suppurative lesions in many organs
Abscesses + Empyemas + Pyogranulomas
What does the exudate from A. pyogenes tend to contain?
Bacteria + Live/Dead NEU + Host cell debris
What is the disease pattern seen in swine infected with A. pyogenes?
Septic arthritis (after farrowing )
What is the disease pattern seen in cattle infected with A. pyogenes?
Severe mastitis (heifers + dry cows)
How does transmission occur in cattle with A. pyogenes?
Flies + Teat contact w/ environment
What allows for there to be a contagious spread of A. pyogenes?
Profuse, purulent secretions
What is the basic treatment for A. Pyogenes?
Incision + drainage of abscesses
Susceptible to AB’s but poor response
Why does A. pyogenes have poor response to AB’s?
Encapsulated abscesses
What are cellular characteristics of Rhodococcus spp.?
Pleomorphic, gram positive to gram variable non spore forming
What cellular morphology can occur with Rhodococcus spp.?
Cocci + Rods + Filaments
What is the cellular preference with Rhodococcus?
Aerobes
What is the typical cell morphology found with R. Equi?
Cocci + Coccobacilli + Rods
What is the reservior for R. equi?
Soil + GI/Feces of healthy animals
What age is R. equi most commonly a oppurtunistic pathogen?
Young foals
What is the main route of infection in R. equi?
Inhalation or ingestion of virulent strains found in contaminated soil
What type of hemolysis is seen with R. equi?
None, aka gamma
What is seen with R. Equi infections?
Granulomas + Pyogranulomas + Abscesses
Where does R. Equi “set up camp” in the body?
Macrophages
What allows R. equi to grow in macrophages?
Vap proteins
What do Vap proteins do?
Protect against phagocytic killing
What is the disease pattern of R. Equi seen in foals?
Pyogranulmatous bronchopneumonia
Why are young foals at risk of R. Equi infections?
Decreased protective Type I Response
Where can lesions occur in foals infected with R. equi?
Pulmonary + Mesenteric LN’s
Intestines
What is the disease pattern of R. Equi in adult horses?
Pneumonia + Extrapulmonary lesions
When do you tend to see R. equi infections in adult horses?
Immunodeficent
What is the disease pattern of R. Equi in swine?
Submandibular + Cervical lymphadenitis
What is the basic treatment for R. Equi?
Combination therapy - Rifampin + Macrolide
Supportive care
What is the cellular morphology of Listeria?
Gram+, non-spore forming coccobacilli
What is the oxygen preference of Listeria?
Facultative anaerobes
Where is listeria commonly found?
Terrestrial + Aquatic
What are the two important spp. of Listeria for us?
Ivanovii + Monocytogenes
What is seen with L. ivanoii?
Abortion in ruminants
What is seen with L. monocytogenes?
Septicemia + Abortion + CNS infections
How is L. monocytogenes transmitted?
Vertical in utero
Ingestion of contaminated foods
How does L. monocytogenes get into the body, basic methods?
Transcellular + Paracellular routes
How does L. monocytogenes get into the CNS?
Breaks into oral or nasal mucosa
Gets to CN
Enters brains
What are the characteristics of brain lesions caused by L. monocytogenes?
Microabscesses - primarily in brainstem
Where does L. monocytogenes tend to grow and live in the body?
Phagocytic + Non-phagocytic cells
What are the virulence factors in L. monocytogenes?
Adhesins + Listeriolysin O
What is listerolysin O?
Allows the bacteria to move around without being detected by AB’s
What is the pattern of disease seen in ruminants with a listeriosis infection?
Encephalitis
Abortion
Septicemia
When is septicemia most commonly seen in cattles with listeria?
Neonates
When do abortions normally occur with listeria?
3rd trimester
What happens with direct inoculation of listeria in cattle?
Conjunctivitis + Opthalmitits
What pattern of disease is seen with pigs + dogs + cats with listeria?
Septicemia form with focal hepatic necrosis
What pattern of disease is seen with horses with listeria?
Neonatal septicemia and abortion
What pattern of disease is seen with poultry with listeria?
Septicemic form with lesions on heart, liver, and abdominal visceria
Pericarditis
Splenomegaly
What is the basic treatment for listeria?
Susceptible to many AB’s
What are the general characteristics of Erysipelothrix?
Gram-positive
Non-spore forming
What is the cell morphology of erysipelothrix?
Rods + Non-branching filaments
What is the oxygen preference of Erysipelothrix?
Facultative anaerobes
What is the most important Erysipelothrix to vet med?
E. rhusiopathiae
What is a specific example of where E. rhusiopathiae can be found in nature?
Fish slime
What is the main reservior for E. rhusiopathiae?
Swine
Where is E. rhusiopathiae found in pigs?
Tonsil + GI tract
How does E. rhusiopathiae invade the body?
Bloodstream - vascular damage and hemorrhagic lesions in diverse organs
Damage to synovial tissues
What are the virulence factors found in E. rhusiopathiae?
Neuraminidase + Hyaluronidase + Capsule
What does neuraminidase do?
Adherence to endothelial cells
What does hyaluronidase do?
helps with invasion of tissue
What does the capsule in E. rhusiopathiae allow for?
Survival and growth in phagocytes
At what age are swine most susceptable to E. Rhusiopathiae?
3 to 18 months
What is seen in swine with E. Rhusiopathiae?
Acute swine erysiplelas
Severe/mild septicemia
What occurs in swine with chronic forms of E. Rhusiopathiae?
Arthritis + Endocarditis
What is seen in young lambs with E. Rhusiopathiae?
Polyarthritis
How does infection of E. rhusiopathiae occur in young lambs?
Umbilicus + Skin wounds
What occurs in adult sheep with E. rhusiopathiae?
Post-dipping lameness
Pneumonia + Endocarditis
What is seen with poultry that have an E. rhusiopathiae infection?
Actue septicemia w/ sudden death
Chronic arthritis with endocarditis may occur
What is the basic treatment for E. rhusiopathiae?
Penicillin + Tetracyclines
None effective for chronic disease