Chapter 11 Flashcards
(46 cards)
Symbiosis
Means to live together
Mutualism
Commensalism
Amensalism
Parasitism
Mutualism - organism one and two benefit, an example is bacteria in the human colon
Commensalism - benefits organism one and organisms two is neither benefited or harmed, example is mites in the human hair follicles
Amensalism - organism one is harmed and organisms two is neither benefited or harmed. Example is fungus secreting an antibiotic,
inhibiting nearby bacteria
Parasitism - benefits organism one and organism two is harmed. Example is tuberculosis or bacteria in the human lung
Symbiotic relationships between microbes and their hosts
Microbiome of humans
- organisms that colonize the body’s surfaces without normally causing disease
- also termed normal microbiota, normal flora, and indigenous microbiota
- two types are:
- resident microbiota
- transient microbiota
What do microbiomes do for us?
- metabolic/nutritional/energy utilization
- competitive exclusion of pathogens
- block pathogens from growing in our bodies - help our immune systems develop properly
- inflammatory response
- T-cell regulation
What are ways that organisms can change and grow in the body
Generally the environment, but more exclusively:
- pH
- temperature
- oxygen
- diet
- our mother
- exposure to radiation
- moisture levels
Commensal microorganisms do what in the body
Commensal microorganisms assist the gut in digesting food and maintaining health
Major physiological processes - pH
- Secretion of acid (HCl) - digestion of macromolecules -> pH of 2
- continues digestion. Absorption of monosaccharides, amino acids, fatty acids, water -> pH of 4-5
- absorption of bile acids, vitamin B12 -> pH 7
What plays a huge role to our microbiome situation of our body
Our mother
- out mother changes the microbiome, the temperature, the foods and many other things
Critical timeframe for intervention
Placental transfer - - - - - —————> 1000 days
Breast - milk -> Bifidobacterium spp & lactobacillus spp
Before:
Formula -> Enterococci & enterobacteria
What do microbiomes do for us?
- bacteria in out gut microbiome use enzymes that can help break down our ingested food more completely than our bodies can on their own
- SCFAs give us 5-15% of energy requirements
- food is broken down better, and more nutrients and energy are extracted
What can microbiomes do for us in regards to pathogens?
- microbiomes can block pathogens from growing in our bodies
- pathogens that make it past our other barriers to infection will need nutrients once inside our bodies
- if our microbiome bacteria are using up those nutrients, then pathogens have a harder time surviving
What causes our microbiomes to change?
- what do we think happens
- list examples of the benefits of the microbiome.
- antibiotics especially the broad-spectrum ones
- our diet, if we change what we eat then our microbiome can change (going from high to low fat can cause a disregulation in the microbiome
- when the body gets sick, the microbiome starts to change a break down. Infections by other microorganisms can start to change the body
- changes in the environment: increased stress, or changed diet, lack of sleep
What the microbiome does for us
- Helps to break down the metabolism and can help to teach the immune system. Can break down molecules so that the body can better use them in the metabolic processes.
- it is in a block so that it can work as a defense mechanism to block bad things like pathogens. Acts as a physical barrier.
- helps digestion by breaking down ingested food (Ie: fiber) so that the body can actually use it as energy.
- Helps the immune system to determine what is good and bad. It trains the immune system
Reservoirs of infectious diseases in humans
- most pathogens cannot survive for long outside their host
- reservoirs of infections
- sites where pathogens are maintained as a source of infection - three types of reservoirs
- animal reservoirs
- human carriers
- nonliving reservoirs
Reservoirs of infectious diseases in humans
- animal reservoirs
- zoonoses
- diseases that naturally spread from animal host to humans
Can acquire zoonoses through various routes:- direct contact with animals or its waste
- eating animals
- bloodsucking methods
- diseases that naturally spread from animal host to humans
- humans are usually dead-end host to zoonotic pathogens (we don’t typically pass it back to animals but rather to other humans)
- difficult to eradicate
What are some common zoonoses
- bubonic plague
- Ebola
- Zika virus
- lice
- Mad Cow disease
- lime disease
- tick fever
- Rabies
- COVID
- Malaria
Reservoirs of infectious diseases of humans
- nonliving reservoirs
- soil, water, and food can be reservoirs of infection
- the presence of microorganisms often due to contamination by feces or urine
Reservoirs of infectious diseases of humans
- human carriers
- asymptomatic infected individuals can be infective to others
- some individuals eventually develop illness, while others never get sick
- healthy carriers may have defensive systems that can protect them
The invasion and establishment of microbes in hosts: infection
- exposure to microbes: contamination and infection
- contamination
- the mere presence of microbes in or on the body
- infection
- when an organism evades body’s external defenses, multiplies, and becomes established in the body
The invasion and establishment of microbes in hosts: infection
- the role of adhesion in infection
- adhesion
- process by which microorganisms attach themselves to cells
- required to establish colonies successfully within the host
- uses adhesion factors
- specializes structures
- attachment molecules
The nature of infectious disease
- infection is the invasion of the host by a pathogen
- disease results if the invading pathogen alters normal body functions
- disease is also referred to as morbidity
That nature of infectious disease:
- causation of disease: etiology
- the study of the cause of the disease
- disease that have various causes
Where does adhesion come in with infectious material
- if there is no point of attachment there is no place for the microbe to attach to
- if the microbe can attach somewhere it is more likely to be able to adhere to the host cell and infect it
What does the microbe attach to
The microbe attaches to the receptor. The microbe has what is called a ligand which is the adhesion factor that connects the microbe to the receptor (glycoprotein) which adheres to the cell
