bacteria

Question 1

staphylococcus

Answer 1

G+,non-motile,non spore forming.facultative anaerobes.S.aureus is coagulase positive.non capsulated.

Question 2

virulence factors

Answer 2

toxins and enzymes

Question 3

toxins

Answer 3

hemolysins ,exfoliative toxins A and B,Toxic shock syndrome toxin-1 and enterotoxins

Question 4

enzymes

Answer 4

Beta lactamase,catalase,coagulase,DNase,hyaluronidase ,lipases,nucleases,fibrinolysin.

Question 5

other virulence factors

Answer 5

slime layer production ,capsule formation and cell wall formation.

Question 6

clinical manifestations

Answer 6

staphylococcal scalded skin syndrome,Toxic shock syndrome,staphylococcal food poisoning and cutaneous infection.

Question 7

SSSS

Answer 7

characterized byperioral erythema and conjuctivitis,cutaneous blisters form and disquamation of the epithelium occurs .The blisters contain clear fluid with no organism.It is mediated by exfoliative toxin .The organism remains localized.Seen commonly in children and infants under 4.

Question 8

Toxic shock syndrome

Answer 8

caused by toxix shock syndromr toxin -1.mostly affects menstruating women.characteristics are;low pressure,fever,extensive skin rash ,desquamation including soles and palms.

Question 9

staphylococcal food poisoning

Answer 9

mediated by enterotoxins that acts as neurotoxins which stimulate vomiting.The enterotoxin is heat stable.symptoms;abdominal pain,cramps,diarrhea,vomiting and nausea.

Question 10

cutenous infection

Answer 10

impetigo,folliculitis,furuncles,carbuncles,bacterimea,endocarditis,osteomyelitis,septic arthritis

Question 11

impetigo

Answer 11

A superficial infection that affects kids on the face and limbs.charactrized by the presence of pustules.This pustules can break and peel away like a localized form of sss.contagious and occurs in areas with pooe hygiene.

Question 12

folliculitis

Answer 12

superficial inflammation of hair follicles. raised domed pustules around hair follicles.

Question 13

furuncles/boils

Answer 13

results when inflammation of a single hair follicle progresses into large red extremly tender abscess.very painful nodules with underlying collection of dead and necrotic tissue.often occur in clusters on parts of the body such as buttocks,back of neck where skin rubs against other skin or clothing

Question 14

carbuncles

Answer 14

furuncles extending to the deeper subcutaneous tissue.created by aggregation and interconnection of a cluster of furuncles.associated with fever and chills .Found in areas of thick tough skin.They can give rise to systemic disease

Question 15

Bacterimia

Answer 15

presence of viable bactetia in blood.

Question 16

endocarditis

Answer 16

caused by bacteremia and affects the right side of the heart.Associated with colonization of the hearts linings ,cardiac abnormalities and rapid destruction of the valves.

Question 17

osteomyelitis

Answer 17

infection of the bone

Question 18

lab diagnosis

Answer 18

examination of abscess material under a microscope.Gram stsining .Culturing on sheep or rabbit blood agar.it will form white golden colonies on blood

Question 19

STREPTOCOCCUS

Answer 19

G+ cocci ,non motile , non sporing and capsulated .capsules contain hyaluronic acid.Form part of normal flora.

Question 20

streptococcus pyogenes

Answer 20

inhabits the throat,pharynx and skin

Question 21

virulene factors-cellular components

Answer 21

C-carbohydrates -protect against lysozymes.Teichoic acid -adherence .M-protein-resistance to phagocytosis and adherence to epithelial cells in the pharynx.Hyaluronic acid -antiphagocytic

Question 22

Extracellular enzymes

Answer 22

streptokinase-prevents formation of fibrin barrier,by activating a host blood factor that dissolves clots.DNase -hydrolyze nucleic acids.Hyaluronidase-spreading factor.Breaks down hyaluronic acid located between tissues allowing for penetration and spread of bacteria into tissues.

Question 23

extracellular toxins

Answer 23

erythrogenic toxin-responsible for immunosupression cytotoxicity.Streptolysin O&S-destroy membranes of erythrocytes .

Question 24

pathogenesis

Answer 24

streptococcal sore throat-pharyngitis.Skin infections-impetigo,erysipelas.Systemic infection-scarlet fever,rheumatic fever and glomerulonephritis

Question 25

pharyngitis

Answer 25

spreads by saliva droplets and nasal secretions .It multiplies in the tonsils causing redness,edema and painful swallowing.Strep stimulates an inflammatory response and lysis of RBCs and WBCs.exudate containing cells and fluids is released ftom blood vessels and deposited in the sorrounding tissue.

Question 26

cellulitis/impetigo

Answer 26

burning itching papules that break and form a highly contageous yellow crust. Impetigo occurs in epidemics among school going children.also caused by s.aureus.

Question 27

Erysipelas

Answer 27

invasive form of skin infection. The pathogen enters through a small wound or incision on the face or extremities and spreads to the dermis and subcutaneous tissues. early symptoms are edema amd redness of the skin near portal of entry.fever and chills . The lesion begins to spread outward producing a slightly elavated edge that is noticeably red ,hot and vescular.

Question 28

post streptococcal diseases

Answer 28

rheumatic fever ,glomerulonephritis.

Question 29

pathogenesis

Answer 29

mechanism of infection and mechanism by which disease develops.

Question 30

infection

Answer 30

invasion of the host by microorganisms,which then multiply in close association with the host tissues.

Question 31

disease

Answer 31

morbid process that does not necessarily involve infection

Question 32

two types of pathogens

Answer 32

primary and secondary pathogens

Question 33

virulence

Answer 33

degree of pathogenicity.Determined by 3 xtics;invasiveness,infectivity and pathogenic potential

Question 34

gram positive cocci

Answer 34

staph,strep,pneumococci,enterococci.

Question 35

gramp positive rods

Answer 35

bacilli,clostridia,corynebacteria,listeria and actinomyces.

Question 36

gram negative

Answer 36

enterobactericeae-E.coli,klebsiella,salmonella,shigella. pseudomonas,bacteroids,legionella,vibrios,campylobacter,neisseria and hemophilus

Question 37

miscelleneous

Answer 37

helicobacter,mycobacteria,treponemes,mycoplasma,rickettsia and chlamydia

Question 38

pathogenesis of staph

Answer 38

Depending on the level of invasion,disease can range from localized to systemic. A local staphylococcal infection presents as an abscess-an inflamed fibrous lesion enclosing a core of pus. Toxigenic disease can present as toxemia due to production of toxins in the body or food intoxication or ingestion of preformed toxin in food. s.aureus produces disease by either production of toxins or direct invasion.It is an opportunistic pathogen causing infection on skin and mucous membrane.

Question 39

scarlet fever

Answer 39

Results from a throat infection with a strain of S.pyogenes carrying a prophage that codes for pyrogenic or erythrogenic toxin or a rash inducing toxin that causes shedding of skin. It is spread by inhalation on infective respiratory droplets. systemic spread of this toxic gives rise to high fever and a bright red diffuse rash over the face ,trunk and tongue. The rash and fever disappears accompanied by desquamation of the epidermis.

Question 40

rheumatic fever

Answer 40

caused by group A streptococci. Caused by inflammatory changes of the heart valves ,joints,vessels,subcutaneous tissues and CNS. symptoms;painful athritis,nodukes under the skin and fever.

Question 41

glomerulonephritis

Answer 41

an inflammatory disease of the renal glomeruli . Damage results from the deposition of antigen antibody complexes in involving the streptococcal M protein . Arises from type III hypersensitivity reactions. They cause destruction of glomerular membrane allowing proteins and blood to leak into urine.