15 Campylobacter + Helicobacter + Vibrio Flashcards
1
Q
GI tract GNB Oxidase +
A
GI tract GNB Oxidase +
- Campylobacter
- Helicobacter
- Vibrio
2
Q
Campylobacter, Helicobacter, Vibrio
A
Campylobacter, Helicobacter, Vibrio
- Curved Gram negative bacilli *
- Not Enterobacteriaceae
-
Oxidase positive *
- (All enterbacteriaceae are oxidase negative)
- Cause Gastrointestinal disease
3
Q
Campylobacter facts
A
Campylobacter facts
-
Curved GNB, “gull-wing” shape
- _S-shaped, spiral rods *_
- Motile (darting motiliy)
- Oxidase positive *
- Microaerophilic (5-10% O2)
- Growth at 42oC *
- Culture –
- Campy or Skirrow media
4
Q
Type of Campylobacter
A
Type of Campylobacter
- C. jejuni
- _Most common cause of bacterial gastroenteritis in US/Canada *_
- more common than Salmonella/Shigella
- C. fetus
- Usually systemic disease – sepsis, thromboplebitis, arthritis, meningitis
- Rare but much more virulent as it resists complement and antibody-mediated serum killing
- C.coli
5
Q
Campylobacter jejuni
A
Campylobacter jejuni
- _Most common cause of bacterial diarrhea in the United States *_, 2 million cases yearly
- Reservoir: GI tracts of humans, animals, _poultry *_
- Transmission:
- Fecal-oral
-
Primarily from poultry
- Inadequately cooked *
- Chopping boards *
- Low infectious dose (as few as 500)→Invades and destroys colonic mucosa → blood, pus in stools
- Rarely penetrates to cause septicemia
- 10 or more bloody stools/day
- Fever, abdominal pain, nausea, vomitting
- Generally self-limiting 3-5 days, but may last longer
-
Complications
- _Guillain-Barre syndrome *_
- **30% cases in US associated with serotype O:19 * **
- Reactive arthritis *
6
Q
Guillain-Barre syndrome
A
Guillain-Barre syndrome
- Guillain-Barré syndrome (GBS) is a rare disorder in which a person’s own immune system damages their nerve cells
- Causes muscle weakness and sometimes paralysis. *
- GBS can cause symptoms that last for a few weeks.
- Most people recover fully from GBS, but some people have permanent nerve damage. In very rare cases, people have died of GBS, usually from difficulty breathing.
- In the United States, for example, an estimated 3,000 to 6,000 people develop GBS each year on average, whether or not they received a vaccination.
- It is believed to be an _autoimmune disorder caused by antigenic cross –reactivity between bacterial capsule and neural tissues*_
- What causes GBS?
- Many things can cause GBS; about two-thirds of people who develop GBS symptoms do so several days or weeks after they have been sick with diarrhea or a respiratory illness.
- Infection with the bacterium Campylobacter jejuni is one _of the most common risk factors for GBS. People also can develop GBS after having the flu or other infections (such as cytomegalovirus and Epstein Barr virus). On very rare occasions, they may develop GBS in the days or weeks after getting a vaccination.*_
7
Q
Campylobacter jejuni diagnosis
A
Campylobacter jejuni diagnosis
- Stool culture
- Microaerophilic, 42oC *
- Skirrow/Campy media
- Treatment
- Supportive: fluid replacement
- If gastroenteritis is severe, or patient is septic – treat with antibiotics – fluoroquinolones (ciprofloxacin)
8
Q
Helicobacter pylori
A
Helicobacter pylori
- Curved GNB, motile
- oxidase positive *
- _UREASE POSITIVE *_
- Colonizes _STOMACH *_
- Reservoir: only humans
- Transmission: person-to-person
- Fecal-oral
- Oral-oral
- Causes disease ranging from
- _Gastritis to gastric/duodenal ulcers and asscociated with cancer stomach *_
9
Q
Helicobacter pylori Pathogenesis
A
Helicobacter pylori Pathogenesis
- Colonizes gastric mucosal cells
- UREASE → ammonia cloud neutralizes stomach acid allows survival
- MUCINASE → allows penetration of mucous layer inflammation
- Vacuolating CYTOTOXIN → destruction of mucous-producing cells
10
Q
Helicobacter pylori causes what diseases
A
Helicobacter pylori causes what diseases
- Causes disease ranging from:
- _Acute, chronic gastritis *_
- _Gastric and duodenal ulcers *_
- Associated with stomach cancers
- Gastric adenocarcinoma *
-
Gastric B cell lymphoma
- Gastric mucosal-associated-lymphoid tissue lymphoma (MALToma) *
11
Q
Helicobacter pylori diagnosis and treatment
A
Helicobacter pylori diagnosis
-
Biopsy with culture
- Histology with Giemsa or silver stain
- Culture with microaerophilic * conditions
- _Urea breath test *_
- 13C-Urea (radioactively-labelled) swallowed → 13C-CO2 detected on exhalation
-
Treatment*
- Proton-pump inhibitor + ampicillin + clarithromycin, treat 10-14 days
- Other similar regimes available
12
Q
Vibrio
A
Vibrio
- Curved (comma-shaped) GNB
- Oxidase positive
-
Motile – polar flagella
- “Shooting” / “darting” motility
- Most Vibrio are halophilic (salt-loving)
- 3 species
- Vibrio cholerae
- V. vulnificuns
- V.parahemolyticus
13
Q
Vibrio cholerae
A
Vibrio cholerae
- Causes Cholera
- Profuse, watery diarrhea “rice water” stool * resulting in massive loss of fluids and electrolytes
- Untreated can result in Hypovolemic shock , death
- Subtypes Of V.cholerae
- V.cholerae O1 – Classical & ElTor subtypes
- V.cholerae O139 (Bengal)
14
Q
Vibrio cholerae: Reservoir, transmission, Outbreaks of cholera
A
Vibrio cholerae: Reservoir, transmission, Outbreaks of cholera
- Reservoir:
- Human colon – carriage can continue for several months after untreated infection *
- Crustaceans, shellfish contaminated from fecally-contaminated waters
-
Transmission: Fecal-oral route
- drinking contaminated water *
- Consumption of undercooked/raw seafood (harvested from contaminated waters)
-
Outbreaks of cholera associated with natural disasters – breakdown in sanitation/proper disposal of human waste
- Cholera outbreak in Haiti following 2010 earthquake
15
Q
Case presentation of cholerae
A
Case presentation of cholerae
- Three weeks after Hurricane Rita hit coastal communities along the Gulf coast; 2 cases of cholera were reported in Louisiana
- A man and his wife developed watery diarrhea (the woman had only mild diarrhea)
- The man was hospitalized the next day with fever, muscle pains, nausea, vomitting, abdominal cramps, severe diarrhea and dehydration
- He rapidly progressed to complete loss of renal function and respiratory and cardiac failure.
- With antibiotic therapy and aggressive rehydration therapy, he eventually recovered.
- Toxigenic V.cholerae O1 biotype El Tor was isolated from both these patients.
