DDT 14 - A review of disease causing bacteria Flashcards
(49 cards)
give examples of gram positive bacteria
Clostridium botulinum Clostridium tetani Bacillus anthracis Staphylococcus aureus Streptococcus pyogenes
Clostridium botulinum
- botulism due to food containing neurotoxin; lethal dose 1-2µg; causes respiratory paralysis, morbidity 65%.
Clostridium tetani
anaerobic, endospores; tetanus or lockjaw due to neurotoxin; convulsive contractions in voluntary muscles; morbidity 50%
Bacillus anthracis
anthrax; septicaemic infection in farm animals but transmissible to humans; Prevention - slaughter and burning.
Staphylococcus aureus
Commonly found on skin and typically will not cause any health issues. However some strains can be highly pathogenic. Emergence of antibiotic-resistant S. aureus now a major health concern worldwide (MRSA)
Streptococcus pyogenes
Common cause of sore throat (strep-throat) but can also cause severe infections including meningitis, pneumonia and necrotizing fasciitis
how does bacillus anthracis reproduce?
Forms spores which can survive harsh conditions for decades. Become re-activated when they enter a host organism
how does bacillus anthracis enter the human body?
Most cases are via the skin but can also occur by inhalation or ingestion of spores. Inhalation is the most dangerous route of infection (up to 90% mortality)
where is clostridium botulinum bacteria most commonly found
in food that has been improperly stored in cans - low O environment
what does clostridium botulinum cause?
severe food poisoning
leading to paralysis
prodcues botulinum toxin - most potent neurotoxin known
how is clostridium botulinum used in medicine?
to treat diseases involving muscle spasms as well as cosmetic surgery (Botox injections)
name examples gram negative bacteria
bacilli - vibrio cholerae, legionella pneumophila, e. coli, salmonella
vibrio cholerae description and how is it transmitted?
Flagellated bacteria – highly motile. Spread through drinking contaminated water
how does vibrio cholerae become toxic to body
Bacteria colonise the intestine and produce cholera toxin – increases secretion of water into the intestine leading to severe diarrhea and dehydration
how is vibrio cholerae treated?
Development of oral rehydration therapy has significantly reduced mortality - millions of lives saved every year
where is legionella pneumophila found
Bacteria most commonly found in water contained within air conditioning systems, showers and water tanks.
how is legionella pneumophila spread?
Spread when water is aerosolized leading to inhalation of bacteria
symptoms of legionella pneumophila
fever headache chills nausea diarrhoea
What can some strains of e.coli cause
cause severe food poisoning, gasteroenteritis, diarrhea and urinary tract infection
e.coli. can be serious for
children and elderly
how is salmonella enterica is spread?
spreads via improperly stored or cooked food especially meat, eggs and dairy.
what does salmonella cause?
Common form of food poisoning, leads to diarrhea, fever, vomiting, and abdominal cramps
salmonella typhi is related to salmonella enterica
typhi is subset of enterica
how is salmonella typhi spread
Spread by contaminated food or water, most common in developing regions with poor sanitation.
