Gram Negative Curved Bacilli and Spirochetes

Question 1

campylobacter species movement

Answer 1

flagellum

Question 2

C. jejuni

Answer 2

species that commonly causes self-limited gastroenteritis

zoonotic infection and obtained from contaminated food

Question 3

C. rectus

Answer 3

has been isolated from periodontal pockets as well as oral implants

Question 4

helicobacter species

Answer 4

produces large amounts of urease; seen in those strains that colonize the stomach NOT those that colonize the intestines

Question 5

H. pylori

Answer 5

bacteria colonize the mucus layer of the stomach; tend to acquire in youth and persists long term

Question 6

H. pylori disease

Answer 6

causes chronic gastritis and peptic ulcers (Barry Marshall’s experiment)

Question 7

what is H. pylori related to

Answer 7

stomach carcinoma = CagA

Question 8

CagA

Answer 8

first bacterial oncoprotein

Question 9

Cag PAI strains

Answer 9

associated with increased virulence; increased inflammation

Question 10

CagA introduction

Answer 10

introduced into cells via type iv secretion system

Question 11

CagA mechanism

Answer 11

phosphorylated CagA bind to SHP2 = first phosphatase that acts as oncoprotein

Question 12

H. pylori virulence factors (THREE)

Answer 12

mucinase - degrade gastric mucus

vacuolating cytotoxin - causes vacuole formation in epithelial cells and calls up neutrophils

urease - neutralize gastric acid; call up monocytes and neutrophils; stimulate pro-inflammatory cytokines; test for this using a clinical sample to ID H. pylori

Question 13

V. cholerae epidemiology

Answer 13

endemic in areas of poor sanitation; transmission via fecal-oral route

Question 14

V. cholerae disease

Answer 14

causes cholera; asymptomatic colonization to sever, life-threatening diarrhea; untreated severe cholera can result in death within a few days; treat with rehydration (oral or iv)

Question 15

V. cholerae pathogenesis

Answer 15

need a high infectious dose

Question 16

cholera toxin

Answer 16

phage-encoded A-5B toxin; B subunits bind, A subunit released; end result = increased adenylate cyclase activity and increase cAMP; overactivation of Cl- channels –> secrete water and electrolytes to balance

Question 17

T. pallidum epidemiology

Answer 17

3rd most common STI

Question 18

T. pallidum disease

Answer 18

causative agent of syphilis

Question 19

Syphilis stages

Answer 19

primary - chancre = single, painless lesion on cutaneous membrane surface

secondary - generalized mucocutaneous rash

tertiary/ late - non-infectious stage

Question 20

congenital syphilis

Answer 20

transmitted through placenta or birth canal’ causes hutchinson’s teeth

Question 21

T. pallidum virulence facctors

Answer 21

limited knowledge due to lack of in vitro cultures (serial passage in rabbit testicles) or in vivo models

fibronectin coating - prevents phagocytosis

most of the tissue damage seen is from the host immune system

Question 22

T. denticola

Answer 22

part of the red complex with p. gingivalis and t. forsythia; strong association to the progession of chronic periodontitis; only motile member of the red complex

most species lack LPS but instead have lipoproteins and glycoproteins

Question 23

T. denticola virulence factors (FOUR)

Answer 23

polymicrobial biofilm association - seen in deep within the plaque biofilm meets gingival epithelium

leucine-rich repeats - increase alveolar bone loss in mice with T. forsythia

metabolic cooperativity - grown with P. gingivalis, binds and work together

densilin - degrades intracellular adhesion prtoeins and downregulates IL-1beta, IL-6, TNF-alpha, and CCL2

Question 24

Borrelia burgdorferi

Answer 24

lyme disease
stage 1 - bull’s eye rash, headache, fever, muscle aches
stage 2- arthritis, muscle pains, possible CNS signs, cardiac change

Question 25

B. burgdorferi virulence factors

Answer 25

phase variation - occurs in the OspC; live in specific niches and invade the host immune system till you are passed on

Question 26

L. interrogans disease

Answer 26

zoonotic disease - urine-water contamination; common to see in ironman triathlon competitors

causes skin/mucosal surface abrasions, chills, headache, muscle pain