Flashcards in Week 9 - Microbiology of GI tract Deck (47):
Wha is the gram status of psuedomonas aeruginosa?
-Gram negative bacilli
Give two examples of obligate aerobes
Give two obligate anaerobes
Name the anaerobic areas of the GI tract
-Parts of the mouth
Why are colonic bacteria essential for life?
-Prevent colonisation by pathogenic bacteria
-Synthesise and excrete essential vitamins eg B12
-Stimulate production of natural antibodies
What are consequences of a diminished microbiota
-Increased susceptibility to infection
-Poorly developed immune system
Name two bacteria which can form endospores
Name 3 aerobic gram positive cocci species
Name 2 aerobic gram negative cocci
Name some gram positive bacilli species
Name 3 gram negative enteric bacilli
What is the gram status of Haemophilus influenzae
-Gram negative bacilli
Name some bacteria which colonise the mouth
When can mouth bacteria begin to be problematic?
-When the host is malnourished, dehydrated or immunocomprimised
Who is at risk of oral thrush?
What is angular chylosis?
-Inflammation of corners of mouth caused by thrush
How is oral thrush treated?
What bacteria often causes dental caries/gingivitis?
-Step mutans (viridans)
What is ludwig's angina?
-Cellulitis of the neck, usually caused by strep mutans
-Rapid progression can lead to asphyxiation via closure of the larynx
What three sites are swabbed for MRSA upon entering hospital?
-Nose, throat and perineum
What are the main bacteria which colonise the nose?
-Strep and staph
Name 3 bacteria which normally colonise the throat
When can viridans streptococci become problematic?
-During dental procedures and anesthesia bacteria may enter blood stream
-Usually cleared but can stick to prosthesis and orthopaedic implants and cause infection
Which group of organisms is mainly responsible for tonsillitis? Name the common organism
What is the main bacterial cause of tonsillitis?
What is a quincy?
-Abscess of the tonsil
What GI pathology is commonly associated with H.pylori?
Name 3 common colonic bacteria
Why are prophylactic antibiotics used in gut surgery?
-Operations on the gut often have abnormal flora and there is a high risk of wound infection
Name an antibiotic regime used in surgical prophylaxis
What is pseudomembranous colitis?
-Inflammation of the colon caused by c.difficile infection
What is the cause of a perianal abscess?
-Blockage of anal gland by faecal matter caused stasis of bacteria leading to multiplication and abscess formation
What colonic bacteria are found perianal skin?
Where are lactobacilli the common commensal?
What makes lactobacilli advantageous to the vagina?
-Converts glycogen to lactic acid to creat an acidic environment which prevents other bacteria and candida albicans from growing
What is the most common cause of UTIs?
-E.coli from GI tract
(then enterococcus faecalis and klebsiella)
What is specific about an infection with pseudomonas aeruginosa?
-Produces green pus in moist environments
What bacteria is responsible for wet/gas gangrene? Explain the process
-Anaerobic digestion of glucose leads to ethanol and CO2 producing bubbles in the skin
Give two characteristic features of tetanus
-Risus sardonicus (lock jaw)
What is the most common cause of nausea and diarrhoea?
What is the most common cause of gastroenteritis?
-Contaminated food or drink
What are the most common organisms which cause gastroenteritis?
What bacteria produce toxins in food which can cause nausea and vomitting?
What is the result of infection with vibrio cholera?
-Effects the ileum to cause water and salt to be actively secreted into the lumen leading to diarrhoea
-Characteristically looks like 'rice-water'
-Rapid severe dehydration follows
Name 2 protozoans which can cause gastroenteritis
Name 4 causes of travellers Diarrhoea