Gram + cocci: Staphylococci Flashcards
1) catalase + producing bacteria and facultatively anaerobic
2) non-motile, non-sporeforming, glucose fermenter
3) normal inhabitant of the skin, mucous membrane and intestine
Staphylococci
What is the family of staphylococci
Staphylococcaceae
Rare strains are fastidious requiring (3)
1) Carbin dioxide
2) hemin
3) menadione for growth
What are exempted staphylococci
1) S. saccharolyticus
2) S. aureus subspecies
3) S. anaerobius (obligate anaerobes, catalase negative)
What is microscopic appearance of to staphylococci?
Spherical cells that appear in clusters, some singly
Culture used on a staphylococci
- BAP - colonies (4-8mm) on agar plate appear creamy, white or light gold
- buttery looking
- others have gray colonies
- B-hemolytic (S. aureus) (complete clear zone)
It uses 0.04 units bacitracin; performed on BAP or MHA
Bacitracin
What is the results of bacitracin for Micrococci and Staphylococci?
Micrococci - susceptible
Staphylococci- resistant
Size of the result of Micrococci in the bacitracin
> or equal to 10 mm zone of inhibition
1) most virulent spp.
2) coagulase +
3) chiefly responsible for the various skin, wound and deep tissue infections due to trauma or abrasion to the skin or mucosal
4) furuncles and impetigo (boils/pigsa)
Staphylococcus aureus
3 types of nasal carriers associated with S. aureus
1) persistent carriers
2) intermittent carriers
3) noncarriers
A nasal carrier that harbor a single strain for a long time
Persistent carriers
A nasal carrier that harbor various strain overtime
Intermittent carriers
A nasal carrier that do not harbor any organism
Noncarriers
Associated diseases and infections in S. aureus (7)
1) toxin-induced disease (SSS or TSS)
2) bacteremia/sepsis
3) UTI
4) acute bacterial endocarditis
5) cutaneous infections
6) osteomyelitis
7) septic arthritis
1) a toxin-induced disease where there is an exfoliative dermatitis
2) primarily in newborns and previously healthy children
Scalded skin syndrome (SSS)
1) a toxin-induced disease that is rare but potentially fatal, multi system disease characterized by a sudden onset of FEVER, CHILLS, VOMITING, DIARRHEA, MUSCLE ACHES and RASH
2) can quickly progress to hypotension and shock
Toxic shock syndrome (TSS)
5 cutaneous infections
1) folliculitis
2) furuncles (boils)
3) carbuncles
4) impetigo
5) purulent abscess
A mild inflammation of hair follicles or sebaceous glands
Folliculitis
1) are large, raised, superficial abscesses
2) can be an extension of folliculitis
Furuncles
1) develop from multiple furuncles which may progress to deeper tissues
2) patients may have fever and chills (systemic infections)
Carbuncles
1) is a superficial cutaneous infection characterized by CRUSTY LESION and VESICLES surrounded by a red border
2) common in children
Impetigo
Secondary to bactemia
Osteomyelitis
An associated disease/infection usually in children
Septic arthritis