Gram Positive Extra Notes

Question 1

MRSA Meaning

Answer 1

Methicillin Resistant (penicillin resistance) Staph Areus

Question 2

Microbrial surface components recognising adhesive matrix molecules Outline

Answer 2

Bacteria antigens binding to host cell receptors enabling attachment to cell (for entry) and eliciting physiological change. Eg fibrin binding protein (allows pathogen to hide in clot) and collagen binding protein

Question 3

Examples of how pathogens evade phagocytosis

Answer 3

Entry into host cells, biofilms (capsules/slime layers) and production of enzymes/cytotoxins to damage/ destroy immune cells

Question 4

Coagulase Pathogen and Biological Function

Answer 4

S Areus. Prevents phagocytosis by engulfing bacteria in clot

Question 5

Protein A Pathogen and Biological Function

Answer 5

Binds IgG preventing phagocytosis

Question 6

Alpha toxin pathogen and biological function

Answer 6

Lysis of blood cells (particularly monocytes and platelets). Decreased immune response

Question 7

Staphylokinase pathogen and biological function

Answer 7

S. Areus. Dissolves fibrin clots. Allows further infection and spread

Question 8

Hyaluronidase pathogen and biological function

Answer 8

S Areus. Breaks down hyaluronic acid in connective tissue allowing infection spread

Question 9

Toxic Shock Syndrome Toxin 1 Pathogen and biological function

Answer 9

S Areus. Stimulates T-cells to produce excess TNF alpha and interleukins 1 ,2 and 3

Question 10

Enterotoxin (A,B,C,D,E and G) pathogen and biological function

Answer 10

S Areus. Causes diahorrea and vomiting when ingested

Question 11

Panton-valentine leukocidin pathogen and biological function

Answer 11

S Areus. Lyses of immune cells by pores in membrane

Question 12

Biofilm biological function

Answer 12

Prevention of phagocytosis and antibiotic contact. Also enables adherence to host cells

Question 13

Clositridium species Outline

Answer 13

Gram positive bacilli. Strict anaerobes. Form endospores and powerful exotoxins

Question 14

Penicillin most susceptible pathogens

Answer 14

Beta-hemolytic streptococci

Question 15

Penicillin resistant pathogens

Answer 15

S Areus

Question 16

Cephalosporin susceptible pathogens

Answer 16

penicillin resistant pneumonia, meningitis (better penetration) and used mainly when penicillin allergy

Question 17

When is vacomycin used

Answer 17

When beta lactam resistant

Question 18

Macrolide Outline

Answer 18

Protein synthesis inhibitors

Question 19

Streptococci Outline

Answer 19

Most are faculative anaerobes and others are strict anaerobes

Question 20

Catalase function

Answer 20

prevents damage done by hydrogen peroxide in air with H2O and O2

Question 21

Haemolysis Def

Answer 21

Break down of blood. Done in alpha, beta and gamma forms

Question 22

Lancefield Classification Outlines

Answer 22

Antigen present on cell membrane

Question 23

Molecular Classification Outline

Answer 23

M Protein gene outline

Question 24

Classification systems

Answer 24

catalase test, lancefiels classifications, haemolysis and molecular classification

Question 25

Alpha Haemolysis

Answer 25

Discolouration of haemoglobin to green colour

Question 26

Beta Haemolysis

Answer 26

Complete breakdown of haemoglobin. White light passes through agar

Question 27

Gama Haemolysis Outline

Answer 27

No change to haemoglobin

Question 28

M Proteins Outline

Answer 28

Mediate attachment to cells, prevent phagocytosis

Question 29

M like proteins outline

Answer 29

Bind IgG and IgM together to prevent antibody attachment

Question 30

Streptococcal Chemokine protease

Answer 30

Cleave II-8. Prevents neutrophile migration in tissues

Question 31

Location of colonisation of beta haemolytic streptococci

Answer 31

Lower GIT and lower gastro-urinary tract

Question 32

VRE Meaning

Answer 32

Vancomycin resistant enterococci. Results of HCAIs. Linezolid is used as a last line treatments

Question 33

Viridans Classification

Answer 33

Alpha hemolysis and little/no lancefield antigens

Question 34

Enetrococci Classification

Answer 34

D lancefield antigens, faculative anaerobes and alpha/beta haemolysis

Question 35

Listeria Moncytogenes Classification

Answer 35

Non-sporing, aerobic and faculative non-aerobic

Question 36

At risk patients for Enterococci

Answer 36

Recent surgery, maligant disease, trauma, antibiotic use (cephalosporin and aminoglycosides) and ICU hospitalisation

Question 37

Listeria Monocytogenes Passes

Answer 37

Vertical transmission, animal transmission and uncooked meats