3.1 Flashcards
endospores
- Formed when bacteria encounter adverse environmental conditions
- Have a tough shell which can resist heat and drying
- Some bacterial species can survive in the environment for more than 100 years and still produce viable bacteria when placed in the right conditions
2 species of genus bacillus
bacillis anthracis, bacillus cereus
bacillus anthracis causes
anthrax
anthrax
isease of livestock and other grazing mammals
□ Humans can get it if they come into contact with infected animals or animal products
□ Spores remain viable for over 100 years
□ Used as a biological warfare agent
3 forms of anthrax
cutaneous, inhalational, gastrointestinal
cutaneous anthrax
◊ Untreated mortality 20%
◊ Occurs sporadically in australia
inhalational and gastrointestinal anthrax
unrelated mortality 100%
® May progress to a septicaemic form which may lead to meningitidis
◊
bacillus cereus
§ Food poisoning associated with the consumption of poorly cooked, reheated rice dishes
§ The endospores enable it to survive the initial cooking
§ Some strains of the species produce enterotoxins which cause severe diarrhoea and vomiting
4 species genus clostridium
clostridium perfringens, clostridium tetani, clostridium botulinum, clostridium defficile
○ Clostridium perfringens 3 diseases
gas gangrene, clostridial food poisoning, necrotising bowel disease
□ Gas gangrene
® Clostridial myonecrosis
® Spores in the soil contaminate wounds, leading to liquefactive necrosis of skin and underlying muscle
® Clostridial myonecrosis
□ Gas gangrene
□ Clostridial food poisoning
® Bacteria growing in beef, pork, chicken, turkey
® Crampy abdominal pain, diarrhoea, self limiting
□ Necrotising bowel disease
® Pig bel
® Associated with inadequately cooked pork in New Guinea feasts
® Try[sin inhibitors in sweet potato prevent gastric juices from destroying the toxin
® Necrosis of bowel or bowel segment
® Pig bel
□ Necrotising bowel disease
® Pig bel
○ Clostridium tetani
§ Produces a neurotoxin which blocks inhibitory nerve impulses
§ Tetanus
§ Tetanus
□ May be produced when bacterial spores contaminate a wound
□ Bacteria growing in the wound produce neurotoxin
□ Muscle rigidity and severe spasms persisting for weeks
□ High mortality in the absence of intensive care
○ Clostridium botulinum
§ Produces a neurotoxin which blocks the release of acetyl choline from motor nerve endings
§ Botulism
□ May result from the ingestion of spores in food or when spores contaminate wounds
□ Flaccid paralysis of the eye, face and limb muscles
□ Muscles or respiration - respiratory failure
□ The toxin (botox) has use in cosmetic medicine where paralysis of small facial muscles relaxes skin wrinkles
○ Clostridium defficile
§ Common cause of diarrhoea in hospitalised patients
risk factors for infection with clostridium defficiel
□ Current or recent use of antibiotics □ Old age □ Being a hospital patient □ Being debilitated □ Recent surgery
clostridium difficile infection
§ May be complicated by a toxic megacolon
□ Distended colon which may rupture
botulism caused by
clostridium botulinum
tetanus caused by
clostridium tetani
