Bacteriology - intestinal Flashcards
Which intestinal bacteria are the most important?
Salmonella
E. coli
Yersinia
Shigella
What media is used as a differential for enterobacteria?
MacConkey bile lactose agar
How does macConkey bile lactose agar differentiate different bacteria?
Bacteria need to be tolerant of bile
Some ferment lactose - produce acid to turm pH red
Are enterobacteria gram positive or negative?
Gram negative
What do enterobacteria look like?
Straight rods
What category of conditions are most enterobacteria?
Facultative anaerobes
What disease does shigella cause?
Dysentry
What disease does yersinia cause?
Invasive intestinal infections
What does salmonella cause?
Enteritis
What different serotypes are there of E. coli?
Enterotoxigenic E. coli
Verotoxigenic E. coli
Attaching and effacing E. coli
Enteroinvasive E. coli
What do enterotoxigenic E. coli do?
Produces toxins that cause diarrhoea
What do verotoxigenic E. coli do?
Produces toxins that cause kidney failure
What do attaching and effacing E. coli do?
Attach and destroy the intestinal wall
What do enteroinvasive E. coli do?
Invade the body and cause sepsis
How are enterobacteria treated?
Supportive - fluids
Antibiotics NOT USED
What does campylobacter look like?
Curved rods
Is campylobacter gram positive or negative?
Gram negative
What category of conditions does campylobacter need?
Microaerophilic (5% O2)
Where is campylobacter found?
Gut of animals (not humans)
Gets into the muscle of white meat
What is the name of the campylobacter that causes GI disease?
C. jejuni, C. coli
What disease can campylobacter cause in cattle and sheep?
Abortion - C. fetus
What enterobacteria are strict anaerobes?
Clostridium
How does clostridium spread?
Spores
What is the main types of clostridium producing neurotoxins?
Clostridium tetani
Clostridium botulinum
How does tetanus cause disease?
Neurotoxins - tetanospasmin
Tetanolysin - aids necrosis
Causes spastic paralysis
How does C. tetanus enter the body?
Deep puncture wounds where there is no O2
What animals get descending tetanus?
Horses and humans - lungs affected first
What is the main source of clostridium bolulinum?
Reheated rice
What symptoms does clostridium botulinum cause?
Flaccid paralysis and death
How can you prevent clostridium botulinum?
Cook food
Avoid spoiled feed
Vaccination
What type of clostridium causes enterotoxaemia?
C. perfringens
What increases the chance of getting C. perfringens?
Change in gut conditions eg. from antibiotics
What type of enterobacteria can cause wound infections and gangrene?
Invasive toxigenic clostridia
