Bacteria and viruses
Name 2 structures that can be present in bacteria but are always absent in viruses
-ribosomes
-cell wall
-plasmids
-flagella
Explain the difference between vehicle- and vector-borne mode of disease transmission
vehicle-borne - through non living substance
vector-borne - living organism transmitting an infection
Explain the difference between bactericidal and bacteriostatic antibiotics
bactericidal - kills bacteria
bacteriostatic - inhibits growth
What diseases does MenACWY vaccine protect against
meningitis
sepsis
Define pyknosis
irreversible condensation of chromatin in the nucleus when a cell undergoes apoptosis
Give 2x examples of functions of gut microbiome
Possible answers:
-protection against pathogens
-vitamin synthesis (K, B12)
-immune system development
-modulation of CNS (gut-brain axis)
-SCFA production
-fat storage promotion
Give 3 examples of pathophysiological processes in sepsis which lead to multiple organ failure
complement activation
coagulation dysfunction
endothelial activation
microvascular dysfunction
Give 2 examples of penicillin medications
Amoxicillin
Flucloxacillin
Temocillin
Ampicillin
Give 2x important guidelines in terms of antibiotic prescription
possible answers:
-Document the indication for antibiotic prescription
-Prescribe the shortest possible antibiotic course which is mostly likely to be effective
-Identify and eliminate the source of infection or reduce bacterial load
Explain mechanism of action of quinolones
inhibit DNA replication
target gyrases, topoisomerases critical in this process
What is the structural difference between Gram+ and – bacteria?
Gram-: 2x membranes; periplasm inbetween containing peptidoglycan; LPS outside
Gram+: 1x membrane; thick peptidoglycan
Name 3 symptoms of meningitis
Neck stiffness, photophobia, fever, headache
Compare mechanism of action of glycopeptides and beta-lactams
Glycopeptides - bind to cell wall subunit and blocks new linkages
Beta-lactams - inhibit PBP enzyme needed for transpeptidation
Give 3 reasons a doctor would prescribe a combination antibiotic therapy
-synergistic effect (work better together)
-broaden spectrum of microbial cover
-prevent resistance
-reduce adverse effects
Explain difference between the terms metaplasia, dysplasia, neoplasia
Metaplasia - one cell type converts into another (benign, reversible)
Dysplasia- irreversible condition where cells have abnormal cellular structure
Neoplasia - new, uncontrolled group not under physiological control
Give 3x examples of bacteria that have developed resistance to many antibiotics
MRSA (methicillin-resistant Staphylococcus aureus)
VRE (vancomycin-resistant Enterococcus)
Clostridium difficili
bacteria which cause multi drug resistant TB
Name types of pneumonia and give 2 examples of causative microorganisms to any of them
-community-acquired
-hospital-acquired
-viral (influenza virus, adenovirus)
-bacterial (Streptococcus pneumoniae, Staphylococcus aureus, Mycoplasma pneumoniae)
-fungal (Candida species, Histoplasma capsulatum)
Give 4 examples of antibiotic classes that can interfere with protein synthesis. Give 1 example of such antibiotic
30s inhibitors
50s inhibitors
tRNA inhibitors
EF-G elongation factor
examples: tetracyclin, erythromycin, puromycin
Identify ways outbreaks of diseases can be identified
Lab reports
Clinical notifications
Public concerns
Demand for related service
Name all the layers above brain starting from skin and ending with pia mater.
Skin --> Periosteum --> Cranium -->
Epidural space --> Dura mater (periosteal + meningeal layers) --> Subdural space --> Arachnoid mater --> Subarachnoid space --> Pia mater (has epipial and intima layers)
Give 3x examples of bacterial diseases, 3x of viral and 3x of fungal ones
Bacterial:
-Tuberculosis
-tetanus
-Lyme disease
-Legionnaire's disease
Viral:
-common cold
-influenza
-COVID-19
Fungal:
-athlete's foot
-candidiasis
-Pneumocytis pneumonia
Explain pathophysiology of pneumonia
-macrophages engulf the pathogen and trigger inflammatory reactions
-macrophages activate cytokines eg TNF-a, IL-8 which recruit inflammatory cells to the site of infection
-they also present these antigens to T cells triggering cellular and humoral defense mechanisms, activate complement and form antibodies
-inflammation of lung parenchyma occurs and makes the lining capillaries leaky
-this leads to exudative congestion
Outline what happens during the penicillin allergy
-mediated by type I hypersensitivity - anaphylaxis
-IgE antibodies bind to mast cells resulting in degranulation (release of histamine etc..)
-signs of anaphylaxis - urticaria, flushing, dyspnea, bronchospasm with wheezing, hypotension, tachycardia
Identify 5 healthcare acquired infections
C. difficile
MRSA
Norovirus
Blood borne viruses (hep. B,C, HIV)
UTI (catheter associated)
Outline 3 ways antibiotic resistance develops in some bacteria
Intrinsic - evolution
Acquired + genetic - mutation
DNA transfer - HGT, conjugation, transduction, transformation