Vibrio Flashcards
Which vibrio spp causes profuse watery diarrhea with characteristic rice water stools?
V cholerae
Signs of cholera infection :
Sunken eye balls
__ fingers
Loss of skin __
Rice water stools
Sunken eyeballs
Washing woman’s hands- wrinkled fingers
Loss of skin turgor – if you pinch the skin, normally it goes back into place but for Cholera patients who are severely dehydrated, the skin doesn’t go back to place
Rice water stools
V cholerae serogroups ass’d with epidemics
Only O1 (and not so much O139) responsible for epidemics
**Virulence factors Cholera toxin and TCP found in O1 and O139**
Antibiotics can __ the course of diarrhea
Predominant Rx for cholera is __
Antibiotics (tetracycline) can shorten the duration of diarrhea but that’s only if you catch the disease early enough. The predominant Rx for cholera is oral rehydration
Patients with ___ are at an increased risk of cholera infection
Hyperchlorhydria: altered stomach acidity. Normally, stomach acid can kill Vibrio but if you’re on an antacid or your stomach pH is otherwise altered, you’re at a higher risk for getting sick with cholera
**note that most infections are subclinical**
Describe how V cholerae causes cholera
Vibrio attaches to the intestinal mucosa via fimbriae and releases Cholera toxin. Note that it does NOT invade the host cells. Cholera toxin causes increased cAMP levels >> chloride secretion >> water diarrhea
___ is another virulence factor that is coregulated with Cholera toxin
The expression of this virulence factor is regulated by the ___ master regulator
Toxin co-regulated pilus is another virulence factor that is coregulated with Cholera toxin
The expression of this virulence factor is regulated by the ToxR master regulator
**ToxR is a virulence factor regulator that is inactive under normal environmental conditions (i.e. when the bug isn’t in the human body). When in the human body, ToxR becomes activated and the CT and TCP virulence are co-expressed**
T/F: There are no cholera vaccines
Falsehood. There are 2 vaccines:
Two-dose cocktail of killed vibrios (mixture of 4 strains)
One-dose live attenuated V. cholerae vaccine** (made at UMSOM**)
How they made the vaccine: they deleted the A subunit (which is the enzymatically active component) and kept the B subunit (which is required for release of the toxin into the host cell. Since that’s the immunogenic part, they kept it so antibodies against that subunit = protective coz they’ll inactivate the entire toxin)
Which Vibrio spp is the leading *bacterial* cause of seafood-ass’d gastroenteritis?
V parahaemolyticus
Presentation of V parahaemolyticus
Watery diarrhea +/- blood
usual cramps/nausea/vomiting
**generally self ltd**
Pathogenesis of V parahaemolyticus mediated by ___
Thermal-stable hemolysin (TDH) enterotoxin
**note that there’s also a T3S that secretes other virulence proteins**
Wound infection following exposure to V __ is characterized by cellulitis +/- vesicles or bullae followed by necrosis
Wound infection following exposure to V vulnificus is characterized by cellulitis +/- vesicles or bullae followed by necrosis
Another syndrome caused by V vulnificus infection is ___
Symptoms include chills, fever, prostration, and hypotension, and skin lesions on extremities
Primary spesis
Which bug causes the pathology below?
V vulnificus
Pathogenesis of V vulnificus is mediated by two things mainly. What are they?
Polysaccharide capsule – resists phagocytosis and serum bactericidal action
Endotoxin >> shock
