Stapphylococcaceae - catalase
Produce catalase
Catalase +
Genus Staphylococcus
Pathogen of animals and man
Commensals
Predisposing factors
- Parasitic opportunism
Significant Staphylococcus in animal health
S. aureus –> Wound infections in animals
S. intermedius –> carnivores
S. epidermidis –> Skin commensal, occasional opportunistic parasite
S. hyicus –> Epidermitis in pigs, greasy pig disease
S. schleiferi –> Otitis externa in dogs
Features of Staphylococcus
Gram + cocci
Clusters
- “staphyle” –> bunch of grapes
Facultative anaerobes
Catalase +
Fermentative
Mannitol salt agar
Resistant to lysozyme
Plasmids
- Antimicrobial susceptibility
Bacteriophage
Staphylococcus classification
Coagulase positive:
Coagulase negative:
Coagulase production –> virulence
Coagulase test:
Slide - bacteria bound coagulase - clumping factor
Staphylococcus parasitic properties: Adhesins
MSCRAMMs - Microbial Surface Components Recognising Adhesion Matrix
Main adhesins: - Fibronectin Collagen Elastin Coagulase
Staphylococcus parasitic properties: Capsule
Capsule
Staphylococcus parasitic properties: Cell wall constituents
Teichoic acid and peptidoglycan containing impedin
Protein A – binds Fc fragment of Ig – Antiphagocytic
Staphylococcus parasitic properties (brief)
Adhesins
Capsule
Cell wall constituents
Tolerate high salt and fatty acids
Staphyloferrin B
Bioactive proteins
Exoenzymes
- Staphylocoagulase, hyaluronidase, staphylokinase
Exotoxins
- alpha toxins - destruction of phagocytes - suppuration (pus)
Staphylococcus - Host factors
Entry via:
Endogenous or exogenous
Hypersensitivity
Phagocytosis is the hosts main defence
- Immune suppression predisposes to disease
Pus results from invasion of compromised epithelium or mucous membranes
Systemic disease if enters blood stream
Staphylococcus - Environmental factors
Shedding of epithelium:
- Contact ¬ Animal ↔ Animal ¬ Human ↔ Animal - Zoonosis ¬ Hygiene important
Staphylococcus aureus (S. aureus)
Coagulase +
Usually haemolytic
Usually minor disease
Can cause serious disease:
Staphylococcus Bovine Mastitis
S. aureus
Inside or outside the udder on the teat skin
Grow well in milk
Lives high up in the glands
Penetrate into interstitial tissue surviving intracellularly
Peracute and chronic
Subclinical –> Clinical lactation
Immunity
Treat for cure
Staphylococcus hyicus
Porcine Exudative Dermatitis
Skin of pigs
- Enter through minor abrasions and bites
Highly contagious
Non pruritic
- Its not itchy
Coagulase + (mostly)
Acetoin (V-P) negative
Exfoliative toxin
Non haemolytic
Staphylococcal Disease - Control & Prevention
Hygiene
Maintain skin health
Minimise likelihood of abrasions / spread
Staphylococcal Disease - Treatment
Address the predisposing factor
Antibiotics
Antimicrobial sensitivity testing
Disinfectants
Genus streptococcus
Important pathogens
Animals and man
Many are commensals
Enterococcaeceae spp.
Features of Streptococcus
Gram + cocci
Chains
Facultative anaerobes
Fastidious growth
Catalase negative
Ferment CHO
Widely distributed
- Many different species
Mucous membranes
Primary pathogens or secondary invaders
Streptococcus - Classification
Haemolysins
Lancefield grouping
Morphology (broth)
- Long chains
- S. agalactiae and S.
equi subsp. Equi
- Flocculent deposit
(strings)Staphylococcus aureus (S. aureus)
Coagulase +
Usually haemolytic
Usually minor disease
Can cause serious disease:
Staphylococcus Bovine Mastitis
S. aureus
Inside or outside the udder on the teat skin
Grow well in milk
Lives high up in the glands
Penetrate into interstitial tissue surviving intracellularly
Peracute and chronic
Subclinical –> Clinical lactation
Immunity
Treat for cure
Staphylococcus hyicus
Porcine Exudative Dermatitis
Skin of pigs
- Enter through minor abrasions and bites
Highly contagious
Non pruritic
- Its not itchy
Coagulase + (mostly)
Acetoin (V-P) negative
Exfoliative toxin
Non haemolytic
Staphylococcal Disease - Control & Prevention
Hygiene
Maintain skin health
Minimise likelihood of abrasions / spread
Staphylococcal Disease - Treatment
Address the predisposing factor
Antibiotics
Antimicrobial sensitivity testing
Disinfectants