Principles of Infection II Flashcards
What is anaerobic bacteria?
Bacteria that grows in the absence of oxygen.
What is aerobic bacteria?
Bacteria that requires oxygen to grow.
What is facultative bacteria?
BActeria that changes its metabolic processes depending on if oxygen is present.
Respiration and fermentation
Key features of a virus
Viruses are not living cells.
Nucleic acid has a coat of protein (capsid)
How do viruses work?
Replicate inside the host cell, then burst and spread the infection to other cells
The attachment stage in the reproduction of virus:
Virus attaches to specific molecules on the cell surface
Penetration stage in the reproduction of virus:
The virus enters the cell.
Endocytosed into cell = viral entry
Uncoating stage in the reproduction of virus:
The outer protein coat (capsid) is removed.
Exposing the nucleic acid.
Replication stage in the reproduction of virus:
Synthesis of nucleic acid (mRNA) and synthesis of protein coats.
viral protein synthesis occurs
Assembly stage in the reproduction of virus:
Protein modification = Maturation
Release stage in the reproduction of virus:
Virus is released from the host cell by Lyisis
What is lysis?
Lysis is the breaking down of the membrane of a cell
How is a virus released?
By cell lysis
What is opsonization?
Phagocytic cells attach to an antibody = phagocytosis
What are anatomical barriers?
Tough/intact barriers that prevent entry of microbiomes
Main White Blood Cells
Neutrophils
Eosinophils
Basophils
Lymphocytes
What is created during the secondary and primary response?
Memory cells
What is the role of memory cells?
Provide a quicker immune response.
They remember the specific antigen protein
The three mechanisms that antibodies go through:
Neutralization
Complement recruitment
Opsonization
What is complement recruitment?
Antigen-antibody complexes are activated. The immune system responds to the bacteria
What are the 4 main stages of infection?
Transmission
Infection
Pathogenicity
Virulence
What are the types of invasions?
Intracellular
Extracellular
List the the host cells defences against bacteria
Cell wall
Capsules - phagocytosis
Toxins
2 host defence cells:
Neutrophils
Macrophages
What are the main evade host defences against viruses?
Antigenic Drift
Antigenic Shift
What is horizontal gene transfer?
This enables bacteria to respond and adapt to their environment.
They share common pathogenic mechanisms and antibiotic resistance
How are virulence factors determined?
Genetically determined
What is a pilus?
Cell adhesion mechanism - thin tube like structure.
What is a donar bacterium?
The donor bacterium carries a DNA sequence called the fertility factor,( F-factor).
