Chapter 11 Flashcards
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