Docsity
Docsity

Prepare for your exams
Prepare for your exams

Study with the several resources on Docsity


Earn points to download
Earn points to download

Earn points by helping other students or get them with a premium plan


Guidelines and tips
Guidelines and tips

Staphylococcus Study: Definition, Identification, Virulence, and Prevention, Quizzes of Microbiology

Comprehensive definitions, terms, and information on the study of microorganisms, with a focus on staphylococcus. Topics covered include identification, taxonomy, physical characteristics, epidemiology, virulence factors, host defense mechanisms, clinical manifestations, prevention, and treatment. The document also covers specific details about staphylococcus, including its characteristics, coagulase test, coagulase-negative staphylococci, and virulence factors.

Typology: Quizzes

2012/2013

Uploaded on 07/25/2013

cantwell77515
cantwell77515 🇺🇸

5

(1)

31 documents

1 / 7

Toggle sidebar

This page cannot be seen from the preview

Don't miss anything!

bg1
TERM 1
FORMAT FOR THE STUDY OF
MICROORGANISMS
DEFINITION 1
1. Identification / Taxonomy / Physical Characteristics2.
Epidemiology3. Virulence Factors4. Host Defense
Mechanisms5. Clinical Manifestations of Disease6. Prevention
/ Treatment
TERM 2
. Identification / Taxonomy / Physical
Characteristics
DEFINITION 2
Gram stain & cell morphologymetabolic characteristics of
growth antigenic composition
TERM 3
Epidemiology
DEFINITION 3
natural host or habitatmode of transmission
TERM 4
Virulence Factors
DEFINITION 4
cellular componentsenzymestoxins
TERM 5
Prevention / Treatment
DEFINITION 5
risk factorsvaccinesantimicrobial drugsdevelopment of
resistance
pf3
pf4
pf5

Partial preview of the text

Download Staphylococcus Study: Definition, Identification, Virulence, and Prevention and more Quizzes Microbiology in PDF only on Docsity!

FORMAT FOR THE STUDY OF

MICROORGANISMS

  1. Identification / Taxonomy / Physical Characteristics2. Epidemiology3. Virulence Factors4. Host Defense Mechanisms5. Clinical Manifestations of Disease6. Prevention / Treatment TERM 2

. Identification / Taxonomy / Physical

Characteristics

DEFINITION 2 Gram stain & cell morphologymetabolic characteristics of growth antigenic composition TERM 3

Epidemiology

DEFINITION 3 natural host or habitatmode of transmission TERM 4

Virulence Factors

DEFINITION 4 cellular componentsenzymestoxins TERM 5

Prevention / Treatment

DEFINITION 5 risk factorsvaccinesantimicrobial drugsdevelopment of resistance

Staphylococcus

Characteristics Gram-positive cocci in grape-like clusters facultative catalase positiveFacultative can grow in either aerobic or anerobic conditionsCatalase test differentiates between strep and staph TERM 7

Staphylococcus - identification / classification

DEFINITION 7 Facultative Gram Positive Cocci | | CATALASE |Negative----------- ----- --------Positive | | Streptococcus Staphylococcus | COAGULASE | Positive----------- --------------Negative | | | | Staphylococcus aureus Staphylococcus epidermidis TERM 8

Catalase Test

DEFINITION 8 catalase2H2O2 -------------------------> 2H2O + O2 (bubbles) Catalase detoxifies H2O2Place hydrogen peroxide on the plate, add catalase, if positive then there will be bubbling TERM 9

Coagulase test

DEFINITION 9 coagulase fibrinogen ----------------------> fibrin clotAn enzyme produced by Staphylococcus aureus that causes fibrin clot formation TERM 10

Other Characteristics of Staphylococcus

aureus

DEFINITION 10 Phenol red mannitol salts agar selective differential media for S. aureus salt resistant growthmannitol fermentation yellow color changeBlood agar plateB-hemolytic

Virulence factors of Staphylococcus aureus

Normally Fab2 region of antibody binds to antigen, Protein Abinds the Fc region of antibody, so antibody is bound backwardand does not mediate normal protective function(s) TERM 17

Important Virulence Factors

DEFINITION 17

- coagulase - cloak w/ fibrin - retard immune response - activity linked to invasive potential- hemolysins & leucocidins (-toxin is both) - exfoliatin - protease cleaves desmosomesshedding of epidermidis - enterotoxins (including toxic shock syndrome toxin)

  • 8 immunologic types / A-H / F is TSST act as superantigens stimulate release of IL-2 & IL-6 from T-cells & IL-1 & TNF from macrophages TERM 18

Inflammatory Manifestations

DEFINITION 18 Skin infections abscess formation (almost any anatomical site) folliculitis hair follicle boil (furuncle) sebaceous gland involvement carbuncle confluent boils impetigo superficial, localized cellulitis subcutaneous, usually diffuse Wound infections ~25% of burn wound infections ~15 - 20% of post- operative wound infections (1-10% of post-operative wounds become infected)) TERM 19

abscess

DEFINITION 19 collection of pus in any part of the body that,in most cases, causes swelling and inflammation around it follicultitis boil/furuncle carbuncle TERM 20

Staphylococcal skin infections

DEFINITION 20 Impetigo Cellulitis - frequently located on limbs but may be anywhere

Inflammatory Manifestations -

Otitis media (2nd most common cause)Sinusitis (both acute & chronic) Systemic infections bacteremia/septicemia (~10-40% fatality) - metastatic abscesses endocarditis (~30 % of all cases) osteomyelitis (most common cause) septic arthritis (most common cause) Pneumonia TERM 22

Toxin-mediated Manifestations

DEFINITION 22 (1) scalded skin syndrome - infants/children (& adults) caused by exfoliatin (2) food poisoning most common cause of bacterial food poisoning in USAsymptoms appear 2- hours after eating foodfood contains preformed toxin ~ 1 g (100,000 S. aureus / gram)the toxin is relatively heat stable TERM 23

Toxin-mediated Manifestations -continued

DEFINITION 23 (3) toxic-shock syndrome fever, headache, muscle pain, vomiting, diarrhearapid breathing, tachycardia, hypotensionskin rash & desquamationdysfunction of several organ systems usually superficial or focal infection - negative blood culture TERM 24

Staphylococcal Toxic Shock Syndrome

DEFINITION 24 ~5-25% of S. aureus strains produce exotoxin F (TSST) ~90% individuals seropositive in adulthood 1978 - TOXIC SHOCK SYNDROME menstruating women / tampon usageNow~ 50% cases nonmenstrual (both women & men) TERM 25

Staphylococcal superantigen(s)

DEFINITION 25 Normal antigen activates Superantigen activates ~ 0.01% of T-cells ~5-20% of T-cells Result large amounts of Il-1, Il-2, & TNF released