Microbio, Pathology and Immunology Flashcards
In short chains/ pairs with 90 capsular types
Strep. Pneumoniae
Vaccine against 23 strains and sensitive to penicillin
Strep. Pneumoniae
Partial Haemolysis - a
- Strep. Pneumoniae
- Strep. Viridian’s
Complete Haemolysis - b
- Strep. pyrogens
- Group B strep
Gram positive Cocci in chains.
- Common Commensals of the upper res. tract, bowel and vagina
Strep. Viridans
Common cause of endocarditis
Strep. Viridans
- Most pathgenic of all STREPTOCOCCUS
Strep. Pyogenes
Produces powerful exotoxins
- Can cause tonsillitis
- Puerperal Sepsis
Strep. Pyogenes
Sensitive to penicillin and amoxicillin
Strep. Pyogenes
Life threatening if pregnant
Strep. Pyogenes
Normal flora of the bowel, not particularly pathogenic
Enterococcus
Common cause of the UTI
Enterococcus
What is E. Faecalis
sensitive to amoxicillin
What is E. Faecium
Resistant
- Can cause mrsa in hospital
Define staphylococcus SPP.
- Aerobic
- Gram Positive
- Cocci in grape like clusters
What is the Coagulase test used for?
To distinguish Staph. Aureus from all other staphlococci
Colonises in the nose and upper respiratory tract (not harmful there)
Staph. Aureus
Strains can produce exotoxins that cause toxic shock syndrome or Panton-Valentine Leukocid
Staph. Aureus
Sensitive to flucoloxacillin
Staph. Aureus
Commonest cause of joint and bone infection
Staph. Aureus
Infection at any site may result in bacteria entering the blood system
Staph. Aureus Bacteria
Patient may become septic —> can cause abscesses
Staph. Aureus Bacteria
Common Cause of Meningitidis
Neisseria Meningitidis
Neisseria Gonorrhoeae
Causes gonorrhoea
They look like e.coli on gram film
The coliforms
Name common gut commensal coliforms
E.Coli
Klebsiella Spp
Proteus
Enterobacter Spp
Gut commensal pathogens
Salmonella Spp
Shigella Spp
Verotoxin (e.coli 0157, e.coli 0104)
Can Cause
- UTI
- Peritonitis
- Bilary tract infection
Coliforms
1st line antibiotic GENTAMICIN
Coliforms
- Gram Positive anaerobic bacilli
- Normal bowel flora
- Found in face and soil
- Clostridium Spp.
Produces spores
- Clostridium Spp.
What does Clostridium Perfringens do?
Causes Gangrene
Describe the bacteriodes
- Gram Negative anaerobic bacilli
- Normal bowel flora
- Non-Pathogenic
Can cause infection if reaches a sterile site such as the PERITONEUM or BILARY TRACT
- Treated by METRONDAZOLE
Bacteriodes
How are pathogens recognised in the human body?
Pathogen associated molecular patterns (PAMPS)
- Express things not found in human cells so are easy to distinguish
Which immune cell tackles Lipopolysaccharide (LPS)
Toll-like receptor 4 (TLR4) (cell surface)
Explain the process of: CLEARANCE OF APOPTOTIC CELLS BY TISSUE-RESIDENT MACROPHAGE
- Apoptotic cells release ‘find-me’ signals to attract and activate macrophages
- Macrophages recognize specific ‘eat-me’ signals expressed on the surface of
apoptotic cells - Macrophages rearrange their cytoskeletal to internalize apoptotic cells
- Digestion of the ingested ‘cargo’
- Secretion of anti-inflammatory mediators
What happens if we fail to remove apoptotic material
- Autoimmune disease
Explain the steps of phagocytosis..
- Receptor binds to the “eat me” signals on the apoptotic cell - resulting in formation of the phagocytic cup
- Cup extends around the target and pinches off, hence forming a phagosome
- Fusion with LYSOSOME to for PHAGOLYSOSOME - leads to degradation of contents
- Debris is the released into the extracellular fluids
How are macrophages enhanced?
cytokines - e.g. IFNγ
Acts on macrophages to
i. Increase production of toxic reactive oxygen and nitrogen species
ii. Increase microbicidal activity
iii. Boost Antigen Presentation capability
Function of Natural Killer (nk) cells
SPECIFICALLY kill virally infected and abnormal cancer cells
What is C function protein?
- A major acute phase protein
- Used as a marker for inflammation
- Enhances phagocytosis
- Complement System activation
opsonizes bacteria, facilitating heir clearance by phagocytes
What is the complement system?
The complement system consists of more than 20 components circulating within the plasma.
- It is a major defence mechanism
- Which contributes to the inflammatory response
The Acute Phase Response and CRP
- Results from the action of cytokines on the liver
- Limits spread of infection and prevents systemic inflammation
Name the 3 enzymes that can destroy antibiotics
- Beta-lactamase
- Extended spectrum beta-lactamase (“ESBL”)
- Carbapenemase (“CPE”)
Neoplasm
New Growth
- Abnormal mass of tissue
- Uncoordinated
> All cells in the tumour appear to have arisen from one parent cell
Features of benign tumours
Surrounding tissue forms a fibrous capsule
- Cells are similar to the normal tissue in which they arise
- NORMAL NUCLEI
What is a G Protein
proteins that act as molecular switches inside cells, and are involved in transmitting signals from a outside a cell to its interior.
Rregulated by factors that control their ability to bind to and hydrolyze GTP to GDP. When they are bound to GTP, they are ‘on’, and, when they are bound to GDP, they are ‘off’
What does “Diapedesis” refer to?
Neutrophils squeeze between the endothelial cells
