Microbiology Flashcards
Vibrio Cholerae Transmission
Contaminated water; Undercooked seafood (raw shellfish)
** Fecal oral transmission
Characteristics of Vibrio Cholerae
1) Curved (comma shaped)
2) Polar Flagella
3) Grows in alkaline media –> acid labile –> Large infectious dose
4) Oxidase Positive
Virulence Factor of Vibrio Cholerae
Cholera Toxin (enterotoxin)
Characteristic Diarrhea
Rice Water Diarrhea
Vibrio Cholerae Treatment
Fluoroquinolones and Oral rehydration w/ electrolytes
Diagnosis of Vibrio Cholerae
Dipstick (rapid initial test)
Stool culture = confirmatory
Vibrio Cholerae MOA
1) Fimbriae attaches to ganglioside receptors in intestinal wall then secretes cholera toxin
2) Increased cAMP via Gs pathway –> Increased Cl- secretion into lumen via CFTR
Campylobacter Jejuni Reservoir
1) Poultry, unpasteurized milk
2) Contact with infected persons or infected animal
Characteristics of Campylobacter Jejuni
1) Curved gram - rod w/ polar flagellum
2) Grows in heat
3) Oxidase +
Virulence Factor Campylobacter Jejuni
1) Motility
2) Adherence
3) Toxin Production (Cytolethal distending toxin)
4) Invasion (Dysentery)
Diseases Caused by Campylobacter Jejuni
1) Enterocolitis (Bloody diarrhea due to invasion)
2) Enteric Fever
3) Reactive Arthritis
4) Guillain-Barre Syndrome
5) Erythema Nodosum
Describe Enteric Fever
Systemic infection associated with abdominal pain and fever
HLA B27 is associated with arthritis, conjunctivitis, and urethritis. This is known as ….
1) Reactive Arthritis
Which bacteria are associated with Reactive Arthritis
1) Shigella
2) Yersinia
3) Salmonella
4) Campylobacter
5) Chlamydia
Guillain-Barre Syndrome is commonly seen in ____ infection.
Campylobacter Jejuni
Describe Guillain-Barre Syndrome
Ascending Paralysis that starts are hands and feet
- absent or depressed deep tendon reflexes
- severe respiratory weakness
Treatment for Guillain-Barre Syndrome
1) Plasma Exchange
2) IVIG
Antibiotic for Camp. Jejuni
Macrolides (Erythromycin)
Reservoir for Shigella
Humans
Characteristics of Shigella
1) M Cell invasion via phagocytosis and evades phagolysosome
2) Uses host cell’s actin cytoskeleton to propel from cell to cell
3) resistant to Gastric Acid –> Low infectious dose
Virulence of Shigella
Shiga Toxin (Exotoxin)
MOA of Shiga Toxin
Inhibits 60 ribosome via cleavage of adenine in rRNA
Disease caused by Shigella
1) Shigellosis (Watery Diarrhea –> Bloody Diarrhea) and Enteric Fever
2) Reactive Arthritis
3) HUS (Hemolytic-Uremic Syndrome) due to Shiga Toxin
4) Toxic Megacolon
Shigella Treatment
1) Fluoroquinolones (Ciprofloxacin)
2) 3rd generation Cephalosporin (Ceftriaxone)
*Antidiarrheal prolong disease
Salmonella Non-Typhoidal Reservoir
1) Animals
2) Products (reptiles, poultry, pets, eggs)
Salmonella Non-Typhoidal Characteristics
1) Acid Labile
2) H2S (all motile enteric bacteria)
- Black colonies on nectar agar plate
3) Encapsulated
Virulence of Salmonella Non-typhoidal
Flagellar Motility and Endotoxin (Lipopolysaccharide)
Disease of Salmonella Non-Typhoidal
Salmonellosis (Gastroenteritis and Food Poisoning)
- Watery-bloody diarrhea, fever, chills, myalgia, and severe vomiting
Salmonellosis typically effect what GI sites
1) Colon
2) Small Intestines
Shigellosis causes bloody diarrhea and commonly affects ___ and ___.
1) Left Colon
2) Ileum
Enteric (Typhoid) Fever Affects which area of the GI
Small Intestines
Complication that is associated with Salmonellosis
1) Sepsis
2) Abscess
Population Salmonella Non-Typhoidal
Young Children and Older Adults (Summer and Fall)
Salmonella Typhi and Paratyphoid Reservoir
Humans
Characteristics of Salmonella Typhi and Paratyphi
1) Highly infectious dose required –> not resistant against gastric acid
2) Hematogenous dissemination is possible
3) Produces H2S
4) Immune response primarily via monocytes
Virulence of Salmonella Typhi and Paratyphi
1) Flagellar Motility
2) Vi Capsule:
- Evasion of neutrophil phagocytosis
- Inhibits complement activates
Disease caused by Salmonella Typhi
1) Typhoid Fever and Paratyphoid Fever (Enteric Fever)
- rose colored macules: Erythematous maculopapular rash
- bloody diarrhea followed by short asymptomatic phase –> bacteremia and fever w/ flu like symptoms
