Bacteria Flashcards
Staphylococcus aureus investigation x3?
Gram +ve cocci
Catalase +ve
–> Coagulase +ve
Diseases caused by staphylococcus aureus? Think main and x4 others
Skin infection (impetigo/cellulitis)
Osteomyelitis/septic arthritis
Pneumonia
Endocarditis
Staphylococcus epidermidis investigation x3?
Gram +ve cocci
Catalase +ve
–> coagulase -ve
Staphylococcus epidermidis disease caused?
Endocarditis (prosthetic valves)
Staphylococcus saprophyticus investigation x3?
Gram +ve cocci
Catalse +ve
–> coagulase -ve
Staphylococcus saprophyticus disease caused?
UTI - honeymoon cystitis
Streptococcus pneumoniae investigation x2?
Gram +ve cocci
Catalase -ve
Streptococcus pneumoniae effect on blood agar and optochin?
Green edge on blood agar
Optochin resistant
Diseases caused by streptococcus pneumoniae? x2
Pneumonia and meningitis
Streptococcus viridians investigation x2?
Gram +ve cocci
Catalase -ve
Streptococcus viridians effect on blood agar and optochin?
Green edge on blood agar and optochin resistant
Streptococcus viridians disease caused?
Endocarditis - rheumatic patients in dental
Streptococcus pyogenes investigation x2?
Gram +ve cocci
Catalase -ve
Streptococcus pyogenes effect on blood agar and which Lancefield?
Clear on blood agar
A
Streptococcus pyogenes will cause x2 main?
Cellulitis and strep throat
Also rheumatic fever/glomerulonephritis/impetigo (if becomes very severe)
Listeria monocytogenes investigation x1 and aerobic/anaerobic?
Gram +ve bacilli
Aerobic
Listeria monocytogenes main in specifically who, and x2 diseases caused?
Meningitis in immunocompromised, sepsis (neonates), abortion in pregnant
Clostridium investigation x1 and aerobic/anaerobic?
Gram +ve bacilli
Anaerobic
Clostridium will cause x4? C.perfringes? C.tetani? C.difficile? C.botulinum?
Perfringes - gas gangrene
Tetani - tetanus
Difficile - pseudoemn colitis
Botulinum - botuilism
Bacillus is notifiable and investigation x2?
Gram +ve bacilli
Aerobic
Bacillus anthracic causes?
Bacillus cereus caused?
Anthrax and food poisoning (rice) respectively
Escherichia coli investigation x1?
Gram -ve bacilli
Effect of E.coli on MacConkey and therefore?
Lactose fermenter as purple
E.coli will cause x4?
Diarrhoea, UTI, pneumonia, Meningitis (neonates)
Klebsiella pneumoniae investigation?
Gram -ve bacilli
Klebsiella pneumoniae effect on MacConkey and therefore?
Lactose fermenter as purple
Klebsiella pneumoniae will cause x2?
Pneumonia
UTI
Nesisseria investigation x2?
Oxidase?
Gram -ve cocci
Oxidase +ve
Nesisseria will cause? x2
Meningitis and gonorrhoea
Haemophilus influenzae investigation?
Chocolate agar?
Gram -ve coccobacilli
VX on chocolate agar
H.influenzae will cause? x4
Meningitis, pneumonia, cellulitis, sinusitis
Legionella pneumophilia investigation x1?
And which test?
Gram -ve coccobacilli
Urine antigen test
Legionella pneumophilia causes? In who?
Severe pneumonia particularly in the immunocompromised
Pseudomonas aeruginosa investigation x3?
Lactose fermenter?
Oxidase?
Gram -ve bacilli
Non-lactose fermenter
Oxidase +ve
Pseudomonas aeruginosa will cause x2?
UTI, pneumonia, sepsis
and smelly sputum
Proteus mirabilis investigation?
Lactose fermenter?
Gram -ve bacilli
Non-lactose fermenter
Proteus mirabilis diseases caused?
UTI, kidney stones
Campylobacter jejuni/coli investigation?
Oxidase test?
Parvobacteria - spiral rods
Oxidase +ve
C. jejuni/coli causes? x2
Giullian Barre, diarrhoea (food poisoning)
H.pylori investigation oxidase test? What shape?
Positive and spiral shape
H. pylori causes?
Chronic gastritis, peptic ulcers
Salmonella investigation; lactose fermenter and oxidase?
Gram -ve bacilli
Non-lactose fermenter
Oxidase -ve
Salmonella disease caused?
Diarrhoea and abdominal pain
Shigella investigation and think lactose fermenter and oxidase test?
Gram -ve bacilli
Non-lactose fermenter
Oxidase +ve
Shigella causes
Dysentry
Mycobacterium tuberculosis causes?
Tuberculosis
Mycobacterium tuberculosis investigation; zeil-nelison stain and culture?
Acid fast bacilli
Culture is Lowenstein-Jenson slopes
What happens in Beta-haemolysis?
Blood cells are completely broken down so will appear clear around the culture
What happens in Alpha-haemolysis?
Greeny hue - Fe oxidised to green colour
What happens in Delta-haemolysis?
Normal haemolysis
What stain is required to see gram -ve bacteria?
Fuchsin or safranin counterstain
Why is a different stain required to see gram -ve bacteria? Constituents of two layers.
Peptidoglycan layer is thinner outer membrane in gram -ve.
Inner leaflet - phospholipid
Outer leaflet - lipopolysaccharide (LPS)
What is a virulence factor?
Any product or strategy that contributes to the pathogenicity/virulence
x5 proteobacteria? (not important to recite all 5, but they are rod shaped)
Shigella flexneri, E.col, Salmonella enterica, proteus mirabilis, klebsiela pneumonia
Why is the Ziehl-neelsen stain used for TB?
TB cell walls are very lipid dense so gram strain can’t penetrate them. Highlighted as yellow-orange on green as acid fast bacteria.
What x3 bacteria can cause STI?
Chlamydia trochmatis, N. gonnorhoea and syphilis
Treatment for bacteria causing STI?
Azithromycin, IM benzep or doxycycline (depends on the STI and individual)
Lactose positive on Mackonkey-lactose agar colour?
Red/purple
Lactose negative on Mackoney-lactose agar (e.g. salmonella)?
White
Why is only a low dose of Shigella required to cause infection?
Acid-tolerant
Why can salmonella cause enteric fever?
Initially there is little damage to the gut mucosa cells, but can spread systemically through the lymphatic system due to survival within macrophages
Vibrio cholerae survives in what environment and can cause what disease?
Saline environment and can cause severe diarrhoeal disease
Why is pseudomonas aeruginosa so dangerous?
Highly resistant to multiple antibiotics so very hard to treat once it has breached the host defenses of the organism
Why reduced incidence of H.influenzae now?
Vaccine present
N. gonorrhea causes which diseases x3?
Proctitis
Gingitis
Pharyngitis
Chlamydia trachomatis causes?
Blindness, conjunctivitis, urethra membrane
What are spirochaetae shape?
Long, slender, helical, highly flexible
What do spirchaetae have as an adaptation to aid in their movement?
Endoflagella between peptidoglycan and outer membrane
Treponema pallidum is the spirocheatae responsible for?
The STD syphilis
Treponema pallidum primary, secondary and tertiary infection?
Primary - localized infection (ulcer)
Secondary - Systemic (joints, muscles, skin, lymph nodes)
Tertiary - granuloma in bone and soft tissue
Which cells do mycobacteria survive very well within?
Macrophages and are very slow growing
Why is TB not considered gram positive?
Won’t strain gram staining paper
Leptospira bacteria will cause which disease?
Weil’s disease
How do mycobacteria differ from normal bacteria?
Intracellular