Rods

Question 1

Regular Rods

Answer 1

Listeria. Erysipelothrix

Question 2

Irregular rods

Answer 2

Corynebacterium. Actinomycetes. Mycobacterium. Propionibacterium. Nocardia

Question 3

Charac. Listera monocytogenes

Answer 3

Small, Gram (+) coccobacilli in pairs. Can grow in refridgerator. Foodborne mortality.

Question 4

L. monocytogenes Virulence

Answer 4

Can penetrate placental barrier, withstands proteases/acid/bile, Mediated by PrfA. LLO

Question 5

Listeriolysin

Answer 5

A cholesterol dependent cytolysin. Helps to rupture endosomes/releasing Listeria. If has more cytotoxic LLO, listeria is less virulent

Question 6

Motility of L. monocytogenes

Answer 6

Flagella-mediated (only respiratory). Actin-mediated (helps to spread in host)

Question 7

Adherence of L. monocytogenes

Answer 7

Bacterial alpha-D-galactose binds E-cadherin of intestinal cells

Question 8

Internalin (Inl A/B/C)

Answer 8

Promotes bacterial endocytosis. Helps Listera cross BBB and feto-placental barriers

Question 9

What helps listeria build a tail?

Answer 9

Listerial ActA helps with the actin nucleation

Question 10

Immunity towards listeria

Answer 10

Cell mediated. NO ANTIBODIES

Question 11

Listeria in healthy adults

Answer 11

Gastroenteritis (about 48 hrs after) for about 2-3 days

Question 12

Listeria in pregnant women

Answer 12

100% risk of vertical transmission to fetus. Can cause premature delivery and still birth

Question 13

Listeria and neonates

Answer 13

Early onset: High mortality, Granulomatosis infantiseptica. Late onset: meningoencephalitis

Question 14

What is cultures to find Listeria?

Answer 14

Blood, CSF, placents, amniotic fluid

Question 15

Positive tests for Listeria

Answer 15

Catalase and CAMP test

Question 16

End to end tumbling motility

Answer 16

Caused by Listeria in liquid medium. Creates umbrella motility in agar medium

Question 17

Charac. Erysipelothrix Rhusiopathiae

Answer 17

Pleomorphic. Gram (+) rod. Slow growing

Question 18

Epidemiology of E. rhusiopathiae

Answer 18

Veterinary pathogen (swine and turkey). Occupational exposure

Question 19

What causes erysipeloid in humans?

Answer 19

E. Rhusiopathiae

Question 20

Erysipeloid

Answer 20

Localized cutaneous lesion. Painful/Pruritic but usually self limiting

Question 21

Identification of E. rhusiopathiae

Answer 21

Gram (+). Not fastidious but grows slow (need at least a week before considered negative). Neg catalase/motility

Question 22

How to distiguish E. rhusiopathiae from L. monocytogenes

Answer 22

Listeria is catalase (+) and motil

Question 23

Corynebacterium

Answer 23

Short, mycolic acids. Non-acid fast irregular rods. Colonizes skin and URT

Question 24

Most important virulence factor of c. diphtheriae

Answer 24

Diphtheria toxin (DTx)

Question 25

What makes DtxR important to C. diphtheriae?

Answer 25

It's an iron sensor bc it is an iron dependent production bacteria

Question 26

Effect of Diphtheria toxin

Answer 26

inhibition of protein synthesis. Leads to pseudomembrane. Typically toxic in kidneys and heart. Is irreversible once in the cell. One toxin cal inactivate all ribosomes in the cell

Question 27

Nasopharyngeal diphtheria

Answer 27

Sore throat/fever. Neck edema in adv stages. Mucosal ulcer may be present. Larger pseudomembrane=poorer prognosis. PM cannot be removed. Resp difficulty. Myocarditis

Question 28

Cutaneous Diptheria

Answer 28

Punched-out ulcerative lesion with necrotic sloughing or PM

Question 29

Septicemic diphtheria

Answer 29

Toxin reaches distant organs via circulation. Cause cause fatal heart failure and polyneuritis.

Question 30

ID of C. diphtheriae

Answer 30

White on blood agar. Black on blood tellurite agar.

Question 31

Corynebacterium minutissimum

Answer 31

Gram (+). Normal in skin flora. Infects inter-triginous regions. Invades upper 1/3 of stratum corneum. Causes Erthrasma

Question 32

Erythrasma

Answer 32

Worldwide disease. More in tropical areas. Usually presents with dark skin discoloration

Question 33

Propionibacterium Acnes

Answer 33

Gram (+) anaerobic rod. Produces propionic acid. Non-toxigenic.

Question 34

Epidemiology of P. Acnes

Answer 34

Common in pilosebaceous glands. Skin changes in puberty increases bacterial growth.

Question 35

Main cause of acne vulgaris

Answer 35

Propoinibacterium acnes