Definition of oral microbiome
Totality of bacteria, virus and fungi in oral cavity
Definition of pathogen & pathogenicity
Microorganisms capable of causing disease
Pathogenicity: ability of organisms to cause disease
Infections that spread from host to host
Communicable disease
4 Factors affecting risk of infection
- Frequency of exposure
- Number of pathogens transmitted
- Virulence of pathogen
- Response of host immune system
Definition of cross infection
transmission of infectious agents between patients and staff within clinical environment
3 Requirements in transmission
- Source of infection
- Mode/vehicle: valid pathway
- Route of transmission: direct/indirect
Community strains & Hospital strains
Community strains: microorganisms brought into healthcare facilities
Hospital strains: microorganisms found in healthcare facilities/associated with people in healthcare environment
2 Types of infections (external/internal)
- Exogenous infection
2. Endogenous infection
3 Routes of transmission
- Contact transmission (direct/indirect)
- Droplet transmission (direct/indirect)
- Airborne transmission
2 Types of droplets when aerosols is used
- Spatter (particles): settle quickly on surfaces
2. Droplet nuclei: evaporate & remain suspended in air for many hours
Definition of opportunistic pathogens
microorganisms with potential to cause disease when opportunity arise, but do not do so under ordinary circumstances
One important characteristic of virus
Metabolic inactivity outside cells of susceptible host - only replicate within living cells
What is nucleic acid in virus surrounded by?
Capsid - Protein shell
7 Steps of virus replication
- Adsorption
- Penetration
- Uncoating & eclipse - release nucleic acid
- Transcription - replicate viral DNA
- Synthesis of viral components - capsid proteins
- Assembly
- Release of virions
