Lecture 11 - Actinobacteria I Flashcards
What are the four types of actinobacteria we must know?
Actinomyces
Nocardia
Dermatophilus
Corynebacterium
Are Actinobacteria gram positive or negative?
Postive
What is the cell morphology or actinobacteria?
Coccoid to filamentous
What is the cell morphology of actinomyces?
Typically rods or filaments w/ branching
What is the oxygen preference of actinomyces?
Facultative or obligate anaerobes
What is needed to grow actinomyces?
Enriched media, plus many are capnophiles
What is the lifestyle type of actinomyces?
Commensals
What is the primary habitat of actinomyces?
oral mucosa + tooth surface
Where else can actinomyces be found?
Nasopharynx + Urogenital tract + Intestinal tract
What is the characteristics of an actinomyces infection?
Endogenous + Noncommunicable + Polymicrobial
What is the typical cause of an actinomyces infection?
Traumatic inoculation
Why do actinomyces infections tend to be polymicrobial?
Other bacteria decrease the amount of oxygen in the area, allowing a more suitable environment
What type of reactions tend to occur with actinomyces?
Pyogranulomatous
What are pyogranulomatous reactions?
Supprative inflammation surrounded by granulomatous elements
What does the exudate of actinomyces tend to contain?
Sulfur granules,
What are the virulence factors of actinomyces?
unknown
What are the four important actinomyces to us?
Bovis + Suis + Viscosus + Hordeovulneris
What does A. Bovis cause?
Lumpy jaw in cattle
What is lumpy jaw?
Indurated, suppurative lesions in soft tissue + bone
Along with osteomyelitis
What does osteomyelitis in lumpy jaw cause?
Tooth dislodgement + Inability to chew _ Mandibular fractures
What does A. suis cause?
Mastitis + occasional infection in lungs, spleen, kidneys etc
What causes mastitis in A. Suis?
Trauma from suckling + weaning
What actinomyces can cause infections in Equine?
A. bovis
What does A. Bovis do to Equine?
Manibular lymphadenopathty
Fistous withers + poll evil
Skin nodules
What are the two actinomyces that effect dogs and cats?
Viscosus + Hordeovulneris
What does A. Viscosus tend to do in dogs and cats?
Subcutaneous abscesses
What is the major cause of A. hordeovulneris infection in dogs and cats?
Fox tails
What does A. hordeovulneris cause?
same as A. vicosus along with abscesses on liver and spleen + septic arthritis
What is the treatment for actinomycosis infections?
Surgery of lesions
Prolonged administration of AB’s
What is done specifically for treatment of bovine lumpy jaw?
Sodium iodide concurrent w/ antibiotics
What are the general characteristics of dermatophilus congolensis?
branching filaments
Motile, coccoid zoospores
What is the oxygen preference of dermatophilus congolensis?
Facultative anaerobe + Capnophilic
What are the most common hosts of dermatophiuls congolensis?
Horse + Sheep + Cattle
How does transmission of dermatophilus congolensis occur?
Direct contact + Fomites + Biting arthopods
What is the main reservoir for dermatophilus congolensis?
Asymptomatic chronically infected hosts
What is the key feature of a stain of dermatophilus congolensis?
Railroad tracts
What symptoms are seen with dermatophilosis?
Exudative dermatitis with formation of scabs and crusts
What are the virulence factors in dermatophilosis?
Enzymes that increase permeability of epidermis
What are the common characteristics of a scab caused by dermatophilosis?
Painless + Nonpuritic + Easily removed
What age is it more common to see extensive lesions caused by dermatophilosis?
Young animals
What occurs with extensive lesions from dermatophilosis?
Secondary bacterial infections
What are the predisposing factors to getting dermatophilosis lesions?
Prolonged rain + Thorny shurbs + Arthropod bites
What is the location of dermatophilosis lesions when they are caused by wet weather?
Dorsum and head
What is the location of dermatophilosis lesions when they are caused by thorny shurbs?
Legs and Face
What is the lesion progression when caused by dermatophilosis?
Papules – Exudate – Paintbrush lesions
What treatment is recommended in mild dermatophilosis infections?
Grooming + isolation in dry quarters
What treatment is recommended in severe causes of dermatophilosis infections?
parenteral AB’s
What is a specific recommendation for dermatophiolsis infections in horses?
Topical treatment
What are the basic characteristics of Nocardia?
Branching filaments that fragment into rods and cocci
partially acid-fast
What is the oxygen preference of Nocardia?
Obligate aerobes
What special structure do Nocardia have that allow them to be widespread in water and soil?
Sprophytes
What are the routes of infection for Nocardia?
Trauma to skin + Teat canal + Inhalation + Ingestion
Is Nocardia contagious?
No
What is seen with Nocardia infections?
Supprating lesions with variable granulomatous features
LN often involved
Hematogenous dissemination may occur
How does Nocardia survive in the body?
Survive + Grow in Phagocytes
What allows Nocardia to grow in phagocytes?
Virulence factors - superoxidase dismutase + catalase
What are the Nocardia disease patterns in ruminants?
Mastitis + Pneumonia + Abortion
What are the Nocardia disease patterns in swine?
Pneumonia + Abortion + Lymphadenitis
What are the Nocardia disease patterns in horses?
Pneumonia + Pleuritis + Systemic abscesses + Cutaneous-subcutaneous lesions + Abortion
What are the Nocardia disease patterns in cats?
Cutaneous-subcutaneous abscesses
Pulmonary + disseminated forms
What are the Nocardia disease patterns in dogs?
Pneumonia, pleuritis w/ empyma
Cutaneous-subcutaneous forms
What is the presumptive method of diagnosing Nocardia?
Staining and finding filamentous - Gram+ - partially acid fast bacteria
What is the definitive method for diagnosing Nocardia?
Antimicrobial susceptiability testing
PCR
What treatment methods are used in Nocardia?
Debridement + drainage of lesions
Prolonged adminstration of trimethoprim-sulfomide
What are the general characteristics of Corynebacterium?
Pleomorphic bacilli, non-spore forming
What are the shapes that Corynebacterium can be found in?
Coccoid + Rod + Club-shaped
What most commonly leads to infection of Corynebacterium?
Tissue trauma
What is the most common species of corynebacterium that is seen in animal infections?
pseudotuberculosis
What animal most commonly sees pseudotuberculosis infections?
Small ruminants
Where does C. pseudotuberculosis survive in the body?
Phagocytes
What are the steps in a C. pseudotuberculosis infection?
Multiplies at site + Spreads to draining lymph nodes
What are the virulence factors found in C. Pseudotuberculosis?
PLD + Cell wall lipids
What is commonly seen with a C. Pseudotuberculosis infection?
LN absecess
What is the most common presentation of C. pseudotuberculosis seen in sheep and goat?
Caseous lymphadenitis
What is the external form of CLA?
Abscesses on superficial LN + Skin + Subcutis
What is the internal form of CLA?
Abscesses on internal organs + LN
What animal is external form of CLA most common?
Goats
Where are abscesses most commonly seen in goats?
Head and neck
What animal is the internal form of CLA most common?
Sheep
What is seen with the internal form of CLA?
Weight loss + Ill thrift `
What are the three forms of C. pseudotuberculosis in equine?
External + Internal + Ulcerative lymphangitis
What is the external presentation of C. pseudoTB in horses?
Abscesses in pectoral region or along ventral midline of abdomen
What is the internal presentation of C. pseudoTB in horses?
Liver + Kidney + Spleen + Lungs
Weight loss + fever + depression + Colic
What does ulcerative lyphangitis due to C. pseudoTB look like in horses?
Severe limb swelling and cellulitis
