Gram Negative Curved Bacilli and Spirochetes Flashcards
campylobacter species movement
flagellum
C. jejuni
species that commonly causes self-limited gastroenteritis
zoonotic infection and obtained from contaminated food
C. rectus
has been isolated from periodontal pockets as well as oral implants
helicobacter species
produces large amounts of urease; seen in those strains that colonize the stomach NOT those that colonize the intestines
H. pylori
bacteria colonize the mucus layer of the stomach; tend to acquire in youth and persists long term
H. pylori disease
causes chronic gastritis and peptic ulcers (Barry Marshall’s experiment)
what is H. pylori related to
stomach carcinoma = CagA
CagA
first bacterial oncoprotein
Cag PAI strains
associated with increased virulence; increased inflammation
CagA introduction
introduced into cells via type iv secretion system
CagA mechanism
phosphorylated CagA bind to SHP2 = first phosphatase that acts as oncoprotein
H. pylori virulence factors (THREE)
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
V. cholerae epidemiology
endemic in areas of poor sanitation; transmission via fecal-oral route
V. cholerae disease
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)
V. cholerae pathogenesis
need a high infectious dose
cholera toxin
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
T. pallidum epidemiology
3rd most common STI
T. pallidum disease
causative agent of syphilis
Syphilis stages
primary - chancre = single, painless lesion on cutaneous membrane surface
secondary - generalized mucocutaneous rash
tertiary/ late - non-infectious stage
congenital syphilis
transmitted through placenta or birth canal’ causes hutchinson’s teeth
T. pallidum virulence facctors
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
T. denticola
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
T. denticola virulence factors (FOUR)
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
Borrelia burgdorferi
lyme disease
stage 1 - bull’s eye rash, headache, fever, muscle aches
stage 2- arthritis, muscle pains, possible CNS signs, cardiac change
B. burgdorferi virulence factors
phase variation - occurs in the OspC; live in specific niches and invade the host immune system till you are passed on
L. interrogans disease
zoonotic disease - urine-water contamination; common to see in ironman triathlon competitors
causes skin/mucosal surface abrasions, chills, headache, muscle pain
