Bacterial taxonomy Flashcards
Define a prokaryote
A cell with no membrane bound organelles i.e. bacteria
Define a facultative anaerobe
A cell capable of aerobic and anaerobic respiration
Define an obligate anaerobe
Cells which die in the presence of oxygen
Define an obligate aerobe
Cells which die without the presence of oxygen
Enterococcus (stain, shape, oxygen, disease)
Gram positive cocci, facultative aerobes, UTI
Difference between enterobacter and enterococcus
Both are faculatative aerobes
EnterobBactEr - gram nEgative Bacillis
EnteroCOccus- gram pOsitive Coccus
Moraxella Catarrhalis (stain, shape, oxygen, disease)
Gram negative, coccus, obligate aerobe, associated with respiratory, ear and sinus infections
Legionella (stain, shape, oxygen, disease)
Gram negative, bacillus, obligate aerobe, pneumonia
Klebsiella (stain, shape, oxygen, disease)
Gram negative, bacillus, facultative anaerobe, pneumonia in the immunosuppressed
Bacillus (stain, shape, oxygen, disease)
Gram positive, bacillus, facultative or obligate aerobe, B. anthracis causes anthrax, B. cereus causes food poisoning
Corynebacterium (stain, shape, oxygen, disease)
Gram positive, bacillus, facultative anaerobe, diphtheria (upper respiratory tract infection)
Listeria (stain, shape, oxygen, disease)
Gram positive, bacillus, facultative anaerobe, infection in pregnancy(stillbirth, preterm labour), neonates (sepsis, meningitis)
Clostridium (stain, shape, oxygen, disease)
Gram positive, bacillus, obligate anaerobe, c. tetani - tetanus, c. difficile-gastroenteritis, c.botulinum - botox
Actinomyces (Stain, shape, oxygen, disease)
Gram positive, bacillus, facultative anaerobe, intrauterine devices, dental infections
Campylobacter (Stain, shape oxygen, disease)
Gram negative, bacillus/s-shaped, facultative anaerobe, gastroenteritis
Haemophilus influenza (stain, shape, oxygen, disease)
Gram negative, bacillus, facultative anaerobe, pneumonia
Difference between campylobacter and clostridium in terms of taxonomy
CampylobactEr - gram nEgative, s shaped rod, facultative aerobe, causes gastroenteritis
ClOStrIdium- gram pOSItive, rod, obligate anaerobe, c. tetani/difficile/botulinum
Proteus (stain, shape, oxygen, disease)
Gram negative, bacillus, facultative anaerobe, wound and urine infections
Helicobacter Pylori (stain, shape, oxygen, disease)
Gram negative, bacillus, facultative anaerobe, stomach ulcer
Salmonella (stain, shape, oxygen, disease)
Gram negative, bacillus, facultative anaerobe, gastroenteritis
Escherichia Coli (stain, shape, oxygen, disease)
Gram negative, bacillus, facultative anaerobe, uti, gastroenteritis
Pseudomonas aeroginosa (Stain, shape, oxygen, disease)
Gram negative, bacillus, obligate aerobe, hospital acquired pneumonia
Bordetella Pertussis (Stain shape, oxygen, disease)
Gram negative bacillus, obligate aerobe, upper respiratory tract infection
What is MacConkey agar?
A growth medium used to identify gram negative bacteria (it kills gram positive bacteria) and to differentiate between lactose fermenting and non-lactose fermenting gram negative rods
Give 3 examples of lactose fermenting bacilli
E. coli, klebsiella, enterobacter
Give 5 examples of non-lactose fermenting bacilli
Proteus, salmonella, pseudomonas, shigella, h. pylori
Give 2 examples of obligate anaerobes
Clostridium (gram positive rod), bacteroides (gram negative rod)
Give 3 examples of gram negative obligate aerobic cocci
3 cocci: Neisseria gonorrhoea, Neisseria menigitides, Moraxella catarrhalis
What is the catalase test used for?
To differentiate between enterococcus and streptococcus (streptococcae are catalase negative because they cannot hydrolyse hydrogren peroxide to water and oxygen)
Which bacteria cannot be differentiated with gram staining?
Chlamydia, mycoplasma and ureaplasm - these bacteria do not have a normal bacterial cell wall, they lack peptidoglycans
Bacteroides (stain, shape, oxygen, disease)
Gram negative, rod, obligate anaerobe, GI infection including appendicitis/abscesses
What is the purpose of the aesculin test?
Aesculin (from horse chesnuts) with bile salts in agar - aesculin hydrolyses to aesculitin. Aesculitin forms a dark brown/black complex on the agar. Enterococcus (gram positive coccus) - forms black rings in aesculin agar = aesculin positive
Which bacteria is aesculin positive?
enterococcus
Which bacteria is catalase negative?
Streptococci
Gardnerella vaginalis (stain, shape, oxygen, disease)
Gram variable, rod, facultative anaerobe, bacterial vaginosis
What does sulphur granules indicate?
Actinomyces
Give 3 examoles of gram negative obligate aerobic baccili
3 rods: legionella, pseudomonas, bortadella