U2.2.1 Gr (+) Cocci : Staphylococcus & Microccus Flashcards
Generalities
Belong to Family Micrococcacea
Micrococci
Generalities
Gram (+) cocci in clusters; in tetrads
Micrococci
Generalities
Usually normal flora and associated with skin lesions and more commonly isolated among immunocompromised patients
Micrococci
Generalities
May be found in the environment
Micrococci
Odd One Out
Other gram positive cocci that may be mistaken for Staphylococcus are the following:
a. Rothia mucilaginosa/Stomatococcus mucilanginosus
b. Aerococcus
c. Allorococcus otitis
d. Micrococcus luteus
d. Micrococcus luteus
Generalities
emerging pathogen (UTI, endocarditis)
Rothia mucilaginosa/Stomatococcus mucilanginosus
Generalities
Belong to Family Staphylococcacae
Staphylococci
Generalities
Gr (+) Cocci (0.5-1.5 um) in clusters, in pairs, singly
Staphylococci
Staphylococci
All are Catalase (+) except
AS
1. S. aureus subsp anaerobius
2. S. saccharoluticus
Staphylococci
All are Modified Oxidase (-)
SLV
1. S. sciuri
2. S. lentus
3. S. vitulus
T/F All Staphylococci are Motile and non-sporeformers
F, all are non-motile and non-spore formers. Bacilli are motile
also called as grape-like clusters
Staphylococci
Staphylococci
Gaseous requirements are aerobic or facultative anaerobe except
AS (same as + in catalase testing)
1. Staphylococcus aureus subspecies
anaerobius
2. Staphylococcus saccharolyticus
T/F Staphylococci are halophilic and nitrate reducers.
T
Staphylococci
Colonical Morphology
Size, Elevation, Consistency, Color
Pinhead/Medium-sized, raised, creamy, lemon yellow or golden yellow colonies
Staphylococci
S. albus color
white
Staphylococci
S. aureus color
golden yellow
Staphylococci
S. citreus color
lemon yellow
T/F Other species in Staphylococcus are non-pigmented
T
An initial test is performed to differentiate the Staphylococcus species
Coagulase Test
Most clinically significant coagulase producing Staphylococci
Staphylococcus aureus
Coagulase Producing Staphylococci
Staphylococcus aureus, other coagulase-producing staphylococci
Odd One Out
Other Coagulase Producing Staphylococci :
a. S. intermedius
b. S. pseudointermedius
c. S. byicus
d. S. delphini
e. S. lutrae,
None, all are coagulase producing Staphylococci HSHJAHHSAJSHASHJAHSHAHAHAHA
Odd One Out
Other Coagulase Producing Staphylococci :
a. S. agnetis
b. some strains of S. schleiferi
c. S. hyicus
d. S. haemolyticus
e. S. scheliferi
d. S. haemolyticus
2 groups of Coagulase Negative Staphylococci (CONS)
Novobiocin Susceptible & Novobiocin Resistant
Novobiocin Susceptible Staphylococci (Choose 2)
a. S. epidermidis
b. S. saprophyticus
c. S. xylosus
d. S. haemoliticus
S. epidermidis & S. haemoliticus`
Novobiocin Resistant Staphylococci (Choose 2)
a. S. epidermidis
b. S. saprophyticus
c. S. xylosus
d. S. haemoliticus
S. saprophyticus & S. xylosus
Clinically Significant Staphylococci (4)
Staphylococcus aureus
Staphylococcus epidermidis
Staphylococcus lugdunensis
Staphylococcus saprophyticus
Odd one out
Less common but implicated as opportunistic pathogens
a. S. warneri
b. S. capitis
c. S. epidermidis
d. S. hominis
e. S. schleiferi
f. S. haemoluticus
c. S. epidermidis
Most clinically significant Staphylococcus species
Staphylococcus aureus
Can be recovered from almost any clinical specimen
Staphylococcus aureus
Odd one out
Virulence Factors of S. aureus
a. Hemolysins (alpha, beta, gamma and delta)
b. Panton Valentine Factor - Leukocidin
c. Beta-Lactamase
d. PBP1
d. PBP1; should be PBP2
Impotant Virulence Factors of S.aureus
Protein A, Capsular Polysaccharide, Peptidoglycan & Techoic Acids, Nucleases
S. aureus
Heat Stable Toxins
Enterotoxins
S. aureus
Enterotoxins for Staphylococcal Food Poisoning
Toxins A, B, D
S. aureus
causes almost all cases of menstruating
TSS
TSST-1
S. aureus
also known as Epidermolytic Toxin
Exfoliative Toxin
S. aureus
Toxin implicated in Ritter-Lyell Disease or Scalded Skin Svndrome or Dermatitis Exfoliativa
Exfoliative Toxin
S. aureus
Also implicated in Bullous Impetigo
Exfoliative Toxin
S. aureus
suppurative infections
Skin Wound Infections
Odd One Out
Skin Wound Infections caused by S. aureus
a. Folliculitis
b. Rashes
c. Furuncles (boils)
d. Carbuncles
e. Bullous impetigo
f. Acne
b. Rashes
S. aureus
Exfoliative dermatitis that occurs among newborns and previously healthy young children; also seen among adults with chronic renal
failure
SSS: Scalded Skin Syndrome
S. aureus
Multisystemic disease
Toxic Shock Syndrome
S. aureus
has 2 categories : Menstruating Associated and Non-
menstruating associated
Toxic Shock Syndrome
S. aureus
S/S: sudden onset of fever, chills, vomiting, diarrhea, muscle pain, rashes, can progress to hypotension and shock
Toxic Shock Syndrome
S. aureus
Involves the ingestion of a preformed enterotoxin from food that is improperly stored
Staphylococcal Food Poisoning
S. aureus
S/S: appear rapidly (incubation period: 2-8hrs); nausea, vomiting, diarrhea, abdominal pain
Staphylococcal Food Poisoning
S. aureus
most common enterotoxin in staphylococcal food poisoning
Enterotoxin A
Most common other infection of S. aureus
Osteomyelitis
Odd One Out
Other infections of S aureus include :
a. Osteomvelitis
b. Staphylococcal pneumonia
c. Staphylococcal bacteremia
d. Staphylococcal sepsis
e. Endocarditis
f. Staphylococcal osteomyelitis
g. Septic Arthritis
d. Staphylococcal sepsis
Staph species
Usually a normal inhabitant of the skin (predominant)
S. epidermis
Staph species
Most common cause of of prosthetic valve endocarditis
S. epidermis
Staph species
Common cause of nosocomial UTIs & prosthetic valve endocarditis
S. epidermis
Staph species
Causes “stitch abscess”
S. epidermis
Staph species
50% of CONS isolates
S. epidermis
Staph species
2nd most Common cause of UTIs
S. saprophyticus
Staph species
Associated with pyelonephritis and cystitis in young women and in older men using catheters
S. saprophyticus
Staph species
Colony counts may be <100,000 CFU / mI but is still significant to be considered as a cause of UTI
S. saprophyticus
Staph species
A cause o f nosocomial infections such as endocarditis, septicemia, meningitis and skin and soft tissue infections
S. lugdunensis
Staph species
Positive for Clumping Factor (slide coagulase)
S. lugdunensis
Staph species
Causes an aggressive type of endocarditis
S. lugdunensis
Staph species
High Mortality Rate
S. lugdunensis
Other Staphylococci
scalp
S. capitis
Other Staphylococci
Some are normal flora of animals
S. intermedius, S. delphini, S. pseudointermedius
ODD ONE OUT
Other Staphylococci include
a. S. warneri
b. S. hominis
c. S. schleiferi
d. S. haemoluticus
All are staphylococci species