3. Family Staphylococcaceae Flashcards
Catalase reaction of the family Staphylococcaceae
Catalase positive
Oxygen requirements of the family Staphylococcaceae
Aerobic to facultative anaerobic
Motility of the family Staphylococcaceae
Nonmotile
Carbohydrate fermented by the family Staphylococcaceae
Glucose
Test used to differentiate species of the family Staphylococcaceae
Coagulase test
Clinically significant coagulase-positive species of the family Staphylococcaceae
Staphylococcus aureus
Clinically significant coagulase-negative species of the family Staphylococcaceae
S. epidermidis
S. saprophyticus
Most clinically important species of the family Staphylococcaceae
S. aureus
Natural reservior of S. aureus
Humans
Shortly after birth, where does S. aureus colonize?
Nasopharynx
Perineum skin
MOT of S. aureus
Direct contact with a colonized carrier
True/False. Symptomatic colonization is more common than asymptomatic colonization of S. aureus
False
Asymptomatic colonization is more common
Superficial skin lesions caused by S. aureus
Furuncles
Impetigo
Boils
Sties
FIBS
Invasive diseases caused by by S. aureus
Pneumonia Arthritis Mastitis Endocarditis Meningitis Osteomyelitis
PAMEMO
Toxin diseases caused by S. aureus
- Scalded skin syndrome (Ritter’s disease)
- Toxic shock syndrome
Localized presentation of Scalded Skin Syndrome
Bullous impetigo (large pustule)
Generalized presentation of Scalded Skin Syndrome
Profuse peeling of the epidermal layer of skin
S. aureus toxin that causes Toxic Shock Syndrome
Toxic shock syndrome toxin-1 (TSST-1)/Enterotoxin F
S. aureus disease that has a higher prevalence with tampon use
Toxic shock syndrome
S. aureus species that are resistant to antibiotics
- Oxacillin-resistant S. aureus (ORSA)
- Methicillin-resistant S. aureus (MRSA)
Antibiotics that ORSA and MRSA are resistant to
Methicillin Oxacillin Nafcillin Penicillin Amoxicillin
MONPA
Nondissemination of S. aureus results to
Local disease (e.g., boils)
Dissemination of S. aureus results to
Pneumonia
Bone and joint infection
S. aureus heat-stable exotoxins that cause diarrhea and vomiting
Enterotoxins
Enterotoxins that are resistant to gastric and digestive acids
Enterotoxins A & D
True/False. Toxins are preformed in foods
True
S. aureus toxin that causes sloughing of the skin; also causes widespread systemic immune response
Epidermolytic toxin
S. aureus toxin, similar to TSST-1 but a different site in skin
Exfoliative toxin
S. aureus hemolysin that destroys RBCs, platelets and tissue
Alpha α-hemolysin
S. aureus hemolysin that destroys RBCs
Beta β-hemolysin
S. aureus hemolysin that causes injury, less lethal
Gamma δ-hemolysin
S. aureus exotoxin that is lethal to PMNs; may suppress phagocytosis
Panton-Valentine leukocidin
S. aureus enzyme that causes coagulation of surrounding
Coagulase
S. aureus enzyme that hydrolyzes hyaluronic acid in connective tissue
Hyaluronidase
S. aureus enzyme that aids colonization by acting on sebaceous glands
Lipase
S. aureus enzyme that breaks down antistaphylococcal lipids made by the host
Fatty acid-modifying enzyme
Protein that is found in S. aureus cell wall; bind Fc portion of Ig to avoid phagocytosis
Protein A
Most common cause of hospital-acquired urinary tract infection
S. epidermidis
Staphylococcous spp. that is predominantly hospital acquired
S. epidermidis
Staphylococcous spp. that causes UTI; predominant in young, sexually active women
S. saprophyticus
Media used for lab diagnosis of Staphylococcal infections
CHROMagar CHROMagar MRSA CNA Mannitol salt agar PEA
Colony morphology of S. aureus
Medium to large
Ivory to yellow
Beta-hemolytic
Catalase reaction of S. aureus
Catalase positive
Coagulase reaction of S. aureus
Coagulase positive
Does S. aureus grow in Mannitol salt agar?
Yes
Colony morphology of S. epidermidis
Small to medium
White
Nonhemolytic
Coagulase reaction of S. epidermidis
Coagulase negative
Colony morphology of S. saprophyticus
Large
50% produces a yellow pigment
Coagulase reaction of S. saprophyticus
Coagulase negative
Novobiocin susceptibility of S. saprophyticus
Novobiocin resistant
S. aureus toxin that causes Scalded Skin Syndrome (Ritter’s disease)
Epidermolytic toxin
Microscopic characteristics of the family Staphylococcaceae
Gram-positive cocci in clusters or tetrads