Host Microbe interaction / Immunology (W5) Flashcards
Give two reasons for preventing microbes from entering food
- to prevent food spoilage
- to prevent food related illnesses
How does fermentation preserve food
It inhibits spoilage bacteria to grow
it causes Lactic acid bacteria to grow, which produce lactic acid and therefore lowers pH so other bacteria can not grow
what are the 7 types of infection
- Clinical
- Subclinical
- Localised
- Systemic
- Iatrogenic (nosocomial)
- exogenous
- endogenous
Define clinical infection
infections with signs and symptoms
Define subclinical infection
infections with pathogen but no symptoms
Define localised infection
Infection that is confined to one area of the body
Define systemic infection
infection spread to different areas of the body
Define iatrogenic infection
infection is caught from a medical practitioner or intervention (hospital)
Define Exogenous infection
infection contracted from external environment
Define Endogenous infection
infection contracted from within human host (eg from mother to fetus)
what are the 5 modes of disease transmission
- Contact transmission (direct or indirect physical contact)
- Common vehicle (food/water/airborne)
- Vectors
- Direct inoculation
- Intra-placental
what are the 4 reservoirs for infectious agents
- Animate - healthy
- Animate - active disease
- Animate - convalescent
- inanimate
What are the 2 types of epidemiological study and what do they mean
- Descriptive epidemiology - track disease using location, age ,time, occupation etc.
- Analytical epidemiology - identify cause, transmission and prevention
what are the 4 classifications/ stages of disease infection within a community
- Endemic - constantly present in community
- Epidemic - widespread disease within a community, only occasionally present
- Pandemic - Widespread epidemic, across multiple communities
- Sporadic - widely scattered disease (singular, irregular, infrequent)
define aetiology
cause of the disease
define morbidity
number made ill
define incidence
number of new cases over a given period
define prevalence
number of cases at a given time (old or new)
what are 3 factors that influence the spread of disease
- Virulence of the pathogen
- Pathogenic transmission mode
- Population susceptibility
what are 3 characteristics of lymph vessels
- collect fluid from tissues and return it to blood
- Circulates in one direction
- Blind end tubes
what are the 2 lymphoid organs in the primary classification and what are their roles
- Red Bone Marrow - site where B cells and pre-T cells are produced and B cells mature
- Thymus - site where T cells mature
What are the Lymph Organ Classifications (Based on function)
- Primary - Pluripotent stem cells (bone marrow and thymus)
- Secondary - Site of most immune response (organs, tissues, lymphocyte recirculation)
what are the 3 parts in the Secondary Lymph organ Classification (based on function)
- Organs (have a capsule) (lymph nodes and spleen)
- Tissues (no capsule) (lymphatic nodules, Tonsils, appendix, peyer’s patch)
- Lymphocyte recirculation (B+T cells move from one place to another, Immune response)
what are the 4 roles of the immune system
- Maintain homeostasis
- surveillance (detect changes)
- Differentiate between self and non-self antigens
- Destroy non-self antigens
What is the difference between the innate and adaptive immune response
innate- non specific defence
Adaptive - response based on recognition of specific invader
Which of the Body defence mechanisms are innate and which are Adaptive
Innate :
- phagocytosis
- inflammation
- NK cells
Adaptive
- cell mediated
- antibody mediated
what are the 4 cardinal signs of inflammation
- redness
- heat
- pain
- swelling
what releases chemical mediators during inflammation
damaged cells and mast cells
what chemicals are released during inflammation
- histamine
- kinins
- complement
- prostaglandins
- leukotactic agents
- leukocytosis inducing factor
what 2 things do chemicals to do blood vessels during inflamation
- increase blood flow by vasodilation
- increase capillary permeability
what does leukotaxis cause during inflammation
- attracts WBCs to the area
- phagocytosis
- healing
- leukocytosis inducing factor (stimulates production + release of WBCs
What makes up the innate immune system’s first line of defence
- Mechanical barriers
- Normal Flora
- Secretions
What makes up innate immune system’s second line of defence
- serum
- White blood cells
what are the 3 antigen presenting cells
- macrophages
- dendritic cells
- B cells
what are the 3 types of lymphocytes and what percent of each of them are present in the body
- T lymphocytes (80%)
- B lymphocytes (15%)
- Natural Killer cells (5%)
what types of cells do natural killer cells kill
- host cells that are infected with virus
- cancer cells
What are the three types of T cells and what do they each do
T-helper (detect antigens and activate macrophages, Tc and B cells)
T-regulator (suppress the immune system when finished)
Cytotoxic T cells (Kill virus infected cells and cancer cells)
what mediates adaptive immunity
Lymphocytes
what is a key ability of Adaptive that Innate does not have
Memory
What are the two branched of the Adaptive immune system
- Humoral immunity (antibody mediated)
- Cell Mediated
what is an antibody
a specialised protein that recognises and attaches to its matching antigen
what cell makes antibodies
B lymphocytes
what are 2 names for the specific region on antigens that antibodies attach to
- Epitopes
- Antigenic Determinants
What are the key differences between the primary and secondary immune responses
Primary:
- has a several day lag
- antibody type is immunoglobulin M (IgM)
Secondary:
- much quicker response
- longer lasting
- antibody type is immunoglobulin G (IgG)
How are cytotoxic T cells alerted that a cell has been invaded
The invaded cell has a wide range of surface receptors against antigens. So when it is infected it will present the matching antigen so the Cytotoxic T cell can bind to it to destroy the cell.
How do natural Killer Cells know to kill the cell
There is reduced MHC 1 proteins on the surface of the cell
How do natural Killer cells kill cells
Antibody Dependant Cell Cytotoxicity
what 2 cells regulate the immune response
T-helper cells - stimulate
T-regulatory cells - inhibit
what is administered for Active and Passive immunity and how long to the last comparatively
Active = antigen, longer lasting
Passive = antibody, shorter lasting
what are the 2 fields of the commercial uses of microorganisms
- Food microbiology
- Industrial microbiology
what 5 things cause food spoilage
- insect or rodent infestation
- physical damage
- chemical damage
- microbial growth
- Enzyme activity
what is the name for aerobic and anaerobic spoilage
aerobic = decay
anaerobic = putrefaction
how (3) can diseases be aquired from food
- direct effects of microbes
- toxins
- microbial effect on food
What are the 3 major approaches to food preservation
- prevent microbial contamination
- inhibit microbial growth and activity
- destroy / remove microbes from food
what are 5 reasons why we treate waste
- to remove pathogens
- to remove toxins
- to prevent contamination of drinking water
- to prevent foul odours
- remove nutrients that cause pollution
what does BOD stand for and what does it mean
Biochemical Oxygen Demand
it is a test that determines levels of biological, degradable organic matter that is present in water
what does high BOD indicate
high levels of organic matter in water
what are 3 uses for bacteriophages
- recombinant DNA technology
- to identify pathogenic organisms
- possible treatment for bacterial infections
what are the 3 stages of wastewater treatment and what do they entail
Primary
- removal of large solids
Secondary
- microbial digestion of organic matter
- hydrolysis
Tertiary
- Physical and chemical methods
