Microbial pathogenicity Flashcards
What is a commensalism relationship?
Where one organism benefits but the other doesn’t. However the other organism doesn’t suffer any loss either
What is a mutualistic relationship?
Where both parties benefit
What is a pathogenic relationship?
The pathogen causes harm to the host
What distinguishes a commensal organism from a pathogen?
The ability to damage the host (i.e. cause disease)
Coryneform bacteria are commensal and are found in the ___________
nasopharynx
What is the nature of a disease influenced by?
Type of microorganism
Virulence factors produced by the organism
Health of the host
Site of infection e.g. lens of the eye is very susceptible
Some organisms can go from being non-pathogenic to being pathogenic. True or false?
True
What is virulence?
A measure of the ease with which a pathogen can establish disease in susceptible host
What is meant by infectivity?
A measure of the ease in which a pathogen can become transferred from an infected host to a susceptible one
What is meant by susceptibility?
A measure of the ease with which an individual may become infected
What does MIN stand for?
Minimum Infective Number
What does MIN indicate?
The number of microbial cells that are required to be introduced to particular sites in the body in order to initiate infection
What is MIN affected by?
Nature of site
route of transmission
host status
organism status
What are the ways in which an organism can get into the body?
Skin Respiratory tract Gastrointestinal tract Eyes Urinary Genital tract
How can an organism leave the body?
Faeces Urine Blood (IV abuse/sex/bites) Semen Saliva Cannibalism
