Gram-negative curved rods Flashcards
T/F: H. pylori is a gram-negative rod that creates an alkaline environment.
true
What lab findings are useful to help diagnose Helicobacter pylor (aka Camylobacter pylori)? (5)
urease positive; spiral gram negative rod; endoscopy; stomach tissue culture; serum anti-H. pylori IgG
How does Vibrio cholerae toxin work?
permanently activates G-protein (continually stimulates cAMP) causing excessive water and electrolytes into the lumen of the intestine.
Describe the clinical presentation of a Campylobacter jejuni enterocolitis.
enterocolitis- 1-7 days incubation followed by fever and acute lower right quadrant pain, foul smelling watery diarrhea with blood or pus. May last 1-2 weeks but is usually self-limiting, with systemic infections in neonates and immunocompromised only.
How does Vibrio cholerae gram stain?
negative
How is Vibrio cholerae transmitted?
fecal-oral, contaminated food or water. Humans can be carriers
How is Campylobacter jejuni transmitted?
fecal oral route, contaminated food or water
What is the morphology of Vibrio cholerae?
curved rod
Identify the major virulence factor associated with Helicobacter pylor (aka Campylobacter pylori).
urease produces NH3 which can buffer stomach acid
What is the clinical manifestation of VIbrio cholerae?
cholera- rapid onset of severe watery diarrhea “rice-water stool” can cause death by dehydration.
What lab findings are useful to help diagnose Vibrio cholerae? (2)
comma shaped gram negative rod; oxidase positive.
What lab findings are useful to help diagnose Campylobacter jejuni? (4)
microaerophillic curved gram negative rod is comma or “S” shaped; requires 42 degrees Celsius and 5% oxygen to grow; oxidase positive; sensitivity to nalidixic acid.
How does Helicobacter pylori (aka Campylobacter pylori) gram stain?
negative
What is the major resevoir for VIbrio parahemolyticus?
salt water
What is the major resevoir for Vibrio cholerae?
feces, water
What are the clinical manifestations of Helicobacter pylor (aka Campylobacter pylori)? (4)
gastritis- intermittent dyspepsia, worse eating. Peptic Ulcer- 90% infected. Gastric ulcer 75% infected. Gastric adenocarcinoma- increased risk due to presence of H pylori.
How does Campylobacter jejuni gram stain?
negative
What is the morphology of Campylobacter jejuni?
curved rod
Identify relevant epidemiology and risk factors associated with Vibrio cholerae. (2)
major epidemics in Southeast Asia, Europe and Africa. Hypochlorhydria or antacid use lowers the infective dose required to get through stomach
How does Vibrio parahemolyticus gram stain
negative
Identify the major virulence/toxicity factors associated with Campylobacter jejuni. (3)
low infectious dose (500 organisms) required for infection. Cholera-like enterotoxin. Penicilin and cephalosporin resistant.
What is the major reservoir for Campylobacter jejuni?
animal feces
What is the pathognomic symptom associated with Vibrio cholerae infection?
rice water stool
What is the morphology of Vibrio parahemolyticus?
curved rod
What is the “most common” associated with Campylobacter jejuni?
one of the most common causes of infectious diarrhea
Describe the food poisoning of Vibrio parahemolyticus.
food poisoning- 24-48 hours after eating contaminated seafood, self-limiting but paiful abdominal cramps and watery diarrhea. Antibiotics are not helpful.
What is the morphology of Helicobacter pylori (aka Campylobacter pylori)?
curved rod
Identify the major virulence/toxicity factors associated with Vibrio cholerae. (3)
01 group produces enterotoxin choleragen which permanently activates G-protein; Very large infective dose required (10^9); Mucinase allows organisms to attach to brush border in the intestine
