Gram Positive Bacteria (9/17)

Staphylococcus:

Examples: S. Aureus, S. Hyicus, & S. Pseudintermedius

  • Characteristics of staphylococcus:

    • Gram positive

    • cocci irregular clusters (aka cluster of grapes)

    • Facultative anaerobes.

  • Transmission:

    • Opportunistic pathogens (they will “hangout” until an infection presents itseld)

    • Commensala on skin and mucous membranes (they can live everywhere)

    • Spread through skin lesions and fomites: inanimate objects that can spread disease. Ex. collars, bottom of shoes, and water bowls.

  • Diseases:

    • Pyoderma: Skin infection

    • Mastitis: Mammary gland infection

    • Staphylococcus Hyicus: Exudative and Expidermitis (aka greasy pig disease).

    • Staphylococcus Aureus: popdodermatitis or bumblefoot (in birds and rodents).

  • Diagnosis:

    • Catalase-postive

    • Coagulase test: Determines species

    • Resistant to Penicillin

  • Prevention:

    • Wash Hands

MRSA

  • Methicillin Resistant Staphylococcus aureus (MRSA)

  • MRSA refters to Staphylococcus aureus bacteria that has acquired resistance to not only methicillin, but multiple antibiotics

Streptococcus

  • Examples:

    • Strep. equi subsp. equi: strangles-severe (respiratory infection)

    • Strep. equi subsp. zooepidemicus

    • Strep. agaloctiae: mastitis

    • Strep. uberis: mastitis

    • Strep. suis: bronchopneumonia

    • Enterococcus faecalis: found in the intestines

  • Characteristics:

    • Gram Positive Cocci

    • Form Chains

    • Non-motile

    • Facultative anaerobes

  • Habitat/Transmission:

    • Opportunistic

    • Commensals on skin and mucous membranes

  • Diseases/Clinical Sign:

    • Pyogenic Infections

    • Abscess forming

    • Respiratory Disease

    • Fever

  • Diagnosis:

    • Catalase-Negative

Corynebacterium

  • Examples: Coryne. pseudotuberculosis & Coryne. renale

  • Characteristics:

    • Gram positive: Rods that appear pleomorphic: Coccoid, club and rod forms.

    • Contain coryne-mycolic acids enables

    • Corynebacterium to survive intracellularly as facultative intracellular pathogen

  • Habitat/Transmission

    • Opportunistic

    • Commensal on mucous membranes

  • Diseases/ Clinical Sign

    • Pyogenic infections

    • Sheep and Goats

      • C. Pseudotuberculosis: Caseous lymphadenitis (CLA)

      • C. renale: Pizzle Rot or Sheath Rot

  • Diagnosis:

    • Catalase-Positive

Rhodococcus Equi

  • Characteristics:

    • Gram Postive

    • Coccobacillus

    • Non-motile

    • Facultative intracellular

    • Aerobic

    • Cell walls contain Mycolic Acid rendering them resistant to most staining dyes.

    • Acid-fast staining procedures use carbolfuchsin that will penetrate the cell wall.

  • Habitat/Transmission:

    • Opportunistic

  • Diseases/Clinical Sign

    • Suppurative

    • Bronchopneumonia of foals.

Actinomyces

  • Example:

    • A. Bovis

    • A. Viscosus

    • Trueperella pyogens

    • Nocardia (Strict Aerobe)

  • Characteristics:

    • Gram Positive; Pleomorphic: branching filaments

    • Non-motile

    • Facultative

    • Anaerobes

  • Habitat/Transmission:

    • Found in the soil

    • Nocardia: Saprophyte

    • Saprophyte: Grows on and acquires nourishment from dead or dying organic matter

  • Diseases/Clinical Sign

    • Pyogenic Infections

    • A. bovis: Lumpy Jaw

Bacillus

  • Examples: B. anthracis & B. cereus

  • Characteristics:

    • Gram Positive Bacillus (Rods)

    • Morphology: long chains or pairs

    • Capable of forming endospores

    • Bacillus anthracis: non-motile

  • Habitat/Transmission

    • Inhalation or ingestion of spores

    • Contact with wound

  • Diseases/Clinical Sign

    • Anthrax: Zoonotic

Erysipelothrix Rhusiopathiae

  • Characteristics:

    • Gram Positive

    • Bacillus (Rods)

    • Non-motile

    • Facultative anaerobes

  • Habitat/Transmission

    • Ingestion and open wounds

  • Diseases/Clinical Sign

    • Chronic infections arthritis and abortion

    • Skin: Diamond Skin

  • Diagnosis:

    • Catalase Negative

Listeria monocytogens

  • Characteristics

    • Gram Positive

    • Bacillus (Rods)

    • Motile at 25 C

    • Facultative anaerobes

  • Habitat/Transmission:

    • Found on herbage and fresh water

    • Saprophyte: Grows on and acquires nourishment from dead or dying organic matter

  • Diseases/Clinical Sign

    • Food borne pathogen

  • Diagnosis

    • Catalase Positive

Alopecia: Hair loss

Pruritic: Itchy sensation (makes you want to scratch)