Lecture 10 - Staphylococcus Flashcards
Is staph gram + or -?
Positive
What type of arrangements does staph make?
Irregular
What the Catalase result for Staph?
Positive
What color are Staph colonies?
White to golden
What is the oxygen preference of MOST staph bacteria?
Facultative anerobes
What is the general characteristics of Staph?
Commensal, found on skin and mucous membranes
Opportunistics pathogens - pyogenic infectiosn
What color is S. Aureus on cows and humans?
Golden
How are the two different groups of Staph separated?
Coagulase + and -
What does coagulase correlate with?
Pathogenicity
What are the two methods for a coagulase test?
Test tube + Microscope slide
What is used in the coagulase test?
Rabbit plasma
What is the test tube coagulase test showing
Secreted enzyme
What is the microscope slide coagulase test showing?
Clumping factors
What are your CoPS staphs?
Aureus spp. Aureus
Pseudintermedius
Hyicus
What are your CoNS staphs?
Xylosus + Sciuri
What are the major pathogenic staphs?
Aureus + Hyicus + SIG
What are the three staphs within SIG?
Intermedius + Pseudintermedius + Delphini
What does it mean to be a major pathogenic staph?
Major cause of Mastitis
What are the main virulence factors on the surface of Staph?
Protein A + MSCRAMMS
What does Protein A in staph do?
Bings IgG by FC
What are MSCRAMMS?
Fibronectin + Collagen binding proteins
What two exoenzymes does staph have?
Coagulase + Urease
What does urease do?
Raises pH of urine
What happens symptomatically with urease?
Struvite crystals can form in kidneys and ureters
What are struvite crystals made out of?
Ammonium magnesium phosphate
What are the types of exotoxins found in staph?
Enterotoxins + TSST-1
What does urease do chemically?
Hydrolyze urea to ammonia + CO2
What are enterotoxins responsible for?
Diarrhea + Vomiting
What does S. aureus enterotoxin normally affect?
Goats, cattle, and sheep
What does S. pseudintermedius normally effect?
Dogs SEC
What type of activity does SE and TSST-1 might have?
Superantigen activity
What bacteria has urease?
S. Pseudintermedius
What are the two types of epidermolytic toxins?
Exforliative + Exforlative-like
What bacteria has Exfoliative toxins?
S. Aureus
What is the effect of the epidermolytic toxin in S. Aurues?
Bullous impetigo + scalded skin syndrome
Digests epidermal intercellular connections
What bacteria have exfoliative-like toxins?
S. hycius + S. pseudointermedius
What does the exfoliative-like toxin in S. hycius do?
Exudative epidermitis in pigs
What are hemolysins?
Membrane damaging toxins
What do hemolysins damage?
RBC + Platlets + Monocytes + LEU + Lipid membranes
What are the four types of hemolysins?
Alpha + Beta + Gamma + Delta
What do alpha toxins do?
Complete lysis - beta-hemolysis
What do beta-toxins do?
Damage membrane rich in lipids
Imcomplete RBC lysis
Does beta-toxin cause alpha hemolysis?
NO
What is another name for gamma toxin?
Leukotoxin
What do gamma toxins do?
Damage leukocytes and lipid membranes
Which staph is most commonly the cause of mastitis in cattle?
S. Aureus
What does S. aureus colonize in the cattle?
Teat skin + canal
Where is the main source of infection in mastitis of cattle with S. Aureus?
Udder
What is the most common progression of S. Aureus infection in cattle?
Chronic sublcinical
What occurs in a chronic subclinical infection of S. Aureus in cattle?
Gradual damage to udder and drop in milk yield
What is normally recommended with a chronic subclinical infection with S. Aureus in cattle?
Culling
Why is a chronic subclinical infection of S. Aureus hard to treat?
Fibrosis + Microabscesses
Is a S. aureus mastitis environmental or contagious?
Contagious
When does acute or peracute infections of S. Aureus tend to occur in cattle?
Early lactation
How does an acute or peracture infection of S. Aureus present in cattle?
Acute swelling of udder quarter
Milk in abnormal with thick clots and pus
When is gangrene possible with a S. Aureus infection in cattle?
Peracute
What is peracute?
Very acute, sudden onset, short course, and violent
What is the vaccine in cattle that can be used for S. Aureus
Lysigin - multivalent, whole-cell lysate, bacterin
When is the S. Aureus vaccine most effectively used?
Healthy young heifers
What are the effects of the S. Aureus vaccine?
Does not prevent infection just makes it easier to handle
No effect on SCC
What disease is seen in poultry with S. Aureus?
Bumblefoot
What is bumblefoot?
Pododermitis, localized lesion on foot
Due to penetration of FB with secondary infection
What symptoms can be seen with S. Aureus in poultry?
Dermatitis + Bacteremia + Osteomyelitis + Arthritis + Synovitis
What other syndromes can occur with S. Aureus, besides bumblefoot?
Battery blister + Broilers
What is battery blister?
Abrasive condition
Skin lesions on wing tips + pelvic region
Why can S. Aureus easily infect hatchlings?
Open navels + immature immune systems
What does S. Aureus cause in older birds?
Septicemia or Death
Multiple body sites of inflammation
Tenozynovitis + Osteomyelitis + Endocarditis + Gruamlomata
What is broilers?
Leg weakness via chondronecrosis + osteomyelitits
What syndrome is caused by S. Aureus in rabbits?
Blue Breast
What is Blue Breat?
Mastitis in rabbits, blue appearance due to lack of blood flow
What occurs with S. Aureus infections in older rabbits?
SQ abscesses + Conjuncitivitis
What is seen with S. Aureus infections in newborns?
Hairless - exudative dermatitis, with high mortality
What is botryomycosis?
Chronic suppurative granulomatous condition
What are botryomycosis lesions composed of?
Mass of fibrous tissue
Foci of pus + sinus tracts
What causes the mass of fibrous tissue in botryomycosis?
Coagulase + Immune response
What disease does S. hyicus cause in pigs?
Greasy Pig Disease
What is greasy pig disease?
Exudative epidermitis
What is the initial presentation of GPD?
Yellowish-brown crust on face and ears
What does GPD progress to?
Skin greasy, covered in dark brown coating
Why in GPD is exudates sometimes increasing?
Increased activity of sebaceous glands
Where are erosions in GPD common?
Snout + Foot pads
Why does death mostly commonly occur in GPD?
Severe dehydration
How is GPD treated?
Early systemic AB’s + topical antiseptic or AB
How can GPD be controlled?
Strict isolation of affected pig
Cleaning/Disinfection
Wash sows with antiseptic before farrowing
Who does S. pseudintermedius most commonly infect, dogs or cats?
Dogs
What is the most common symptom of S. pseudintermedius?
Pyoderma w/ alopacia
What is folliculitis?
Small, reddened lesions, hair follicles infected
What is furuncles?
boils, large hemorrhagic bullaE
What are the three types of pseudintermesius that are considered most important?
Shleiferi ssp. coagulans
Shleiferi ssp. shleiferi
Felis
What are S. Shleiferi ssp coagulans most common symptoms?
Pyoderma + Otitis externa
What are S. Shleiferi ssp. sheiferis most common symptoms?
Pyoderma
What is S. felis responisble for?
UTI in cats
What are the CoPS pseudintermedius?
Shleiferi spp coagulans
What are the CoNS pseudintermedius?
Shleiferi spp. Shleiferi
Felis
How can staph be diagnosed via direct microscopy?
Neutrophils containing gram+ Staph
What three media should be used to culture staph?
Blood Agar (sheep) + MacConkey
Mannitol Salt Agar
Purple agar
What is purple agar used with Staph?
Differentiate amoung staph
Why is Mannitol salt agar used to culture staph?
see contaminated samples
Why is MacConkey used for Staph isolation?
Selective for gram-negative, shows you what else might be occurring
What AB’s are recommended for Staph treatment?
First gen cephalosporins
B-lactamase resistant penicillins
Aminoglycosides
What are the examples of aminoglycosides?
Gentamicin + Tobramycin
What two topical treatments are recommended with Staph?
Mupirocin + Fusicdic acid
What does mupirocin do?
Binds to tRNA synthetase
What does fusidic acid do?
Target EF, no more translation