Campylobacter and Helicobacter pylori

GRAM NEGATIVE RODS
Campylobacter
Diseases
C. jejuni is a frequent cause of enterocolitis, especially in children. C. jejuni
infection is a common antecedent to Guillain-Barre syndrome. Other Campylobacter
species are rare causes of systemic infection, particularly bacteremia.
Important Properties
Campylobacters are curved, gram-negative rods that appear either comma- or
S-shaped. They are microaerophilic, growing best in 5% oxygen rather than in the
20% present in the atmosphere. C. jejuni grows well at 42°C, whereas Campylobacter
intestinalis does not—an observation that is useful in microbiologic diagnosis.
Helicobacter
Diseases
Helicobacter pylori causes gastritis and peptic ulcers. Infection with H. pylori is
a risk factor for gastric carcinoma and is linked to mucosal-associated lymphoid
tissue (MALT) lymphomas.
Important Properties
Helicobacters are curved gram-negative rods similar in appearance to
campylobacters, but because they differ sufficiently in certain biochemical and
flagellar characteristics, they are classified as a separate genus. In particular,
helicobacters are strongly urease-positive, whereas campylobacters are ureasenegative.