Washington State University Chapter 11 Existence of Viruses Discussion I want you to write two small paragraphs for each video Define: Antigen present
Washington State University Chapter 11 Existence of Viruses Discussion I want you to write two small paragraphs for each video
Define:
Antigen presenting cells
Bacteroidetes
Firmicutes
Gluten
M proteins
Neurotoxin
Prebiotics
Probiotics
Quorum sensing
Strains
1st video
2nd
3rd
4th
5th Chapter 11
The Human Microbiome
Copyright © 2018 by John Wiley & Sons, Inc. All rights reserved.
Section 11.1: What Is the Human Microbiome?
Bacteria are ubiquitous microscopic organisms that may have been the
first life forms on the plant
Only 1% of total bacterial species are pathogenic to humans
Bacteria are prokaryotes that lack a nucleus yet they can survive very
harsh environments
It is believed that bacteria originally used carbon dioxide as their carbon
source and the oxygen we breath can from photosynthesizing bacteria
called cyanobacteria.
Cyanobacteria still produce a large amount of oxygen today
Bacteria are important part of life on Earth and help maintain the nutrient
cycles that keep plants and animals alive
Nitrogen is converted from atmospheric gas to a usable organic
compound by bacteria
Copyright © 2018 by John Wiley & Sons, Inc. All rights reserved.
Evolution of Life on Earth
Copyright © 2018 by John Wiley & Sons, Inc. All rights reserved.
Bacteria Communicate with One Another
Bacteria work together to influence the environment
Bacteria uses quorum sensing for communication
Bacteria are able to sense when their population reaches the minimum
number of cells needed to impact the environment and make the required
changes need
Quorum sensing is a simple yet elegant process
Transcription of mRNA
Bacterial ribosome translates the mRNA into proteins
One of the proteins is called an autoinducer
They are signaling proteins unique to each species of bacteria
Once they are pumped out of the bacteria they are called inducers which
can bind to bacterial cell receptor which then triggers an increase of
autoinducers trigger a positive feedback loop
The likelihood of a single bacteria capable of triggering this loop is low but if
there are a population of bacteria then the likelihood is much higher
Copyright © 2018 by John Wiley & Sons, Inc. All rights reserved.
Inducers and Receptors
The greater the population of bacteria
the higher the number of inducers
This chemical calling card alert bacteria
to the growing number of their won
species
Each bacterial species creates a generic
inducer that is not species specific so it
can alert bacteria to the presence of
another bacterial species
Many different species can cooperate to
produce necessary enzymes, etc.
One example is when one species
develops a protein that destroys
antibiotics the other species gain the
resistance without having to generate
their own defensive proteins
Copyright © 2018 by John Wiley & Sons, Inc. All rights reserved.
Quorum Sensing is Effective Communication
Quorum sensing is effective for many different kinds of bacterial
communication such as biofilm formation, virulence, and
antibiotic resistance
Biofilms are a complex structure composed of many different
colonies of bacteria and other microbes such as yeast and fungi
They adhere to each other and to surface forming a new
environment with the cells inside the biofilm acting differently
than the ones outside the biofilm
The entire biofilm acts as an individual organisms sharing genes
and coordinating activities
Biofilms are important in human health as some biofilms can
contain pathogenic bacteria and adhere to surgical instruments,
flatware and sinks.
Copyright © 2018 by John Wiley & Sons, Inc. All rights reserved.
Biofilm as an organism
Copyright © 2018 by John Wiley & Sons, Inc. All rights reserved.
Quorum Sensing
Quorum sensing is a communication system that allows for the coordinated
response of individual bacterial cells acting as an organism
Once Quorum is detected then bacteria can up-regulate the production of other
proteins
This production and release of new proteins are coordinated so they are released
at once flooding the environment with the new chemicals altering the
environment
In the human body, these large changes are associated with disease states or
physiological alterations
Pathogenic bacteria like streptococcus cannot cause disease when numbers
are low as the adherence and virulence factors are metabolically expensive
to produce
However once quorum is reached and the numbers are high enough then the
M proteins and adhesins are produced causing disease and allowing the
bacterial colonies to grow and thrive
Copyright © 2018 by John Wiley & Sons, Inc. All rights reserved.
Process of Protein Production
Copyright © 2018 by John Wiley & Sons, Inc. All rights reserved.
Human Microbiome
Humans contain almost as many human cells (~30 trillion) as bacterial
cells (~45 trillion)
Bacterial cells form your personal microbiome and though there are
similarities among all humans to composition of species in the
microbiome there are individual differences
Very little is know about the influences these bacteria have on our
health and wellness
Human Microbiome Project started in 2008 to characterize and analyze
the role of microbes in human health and disease
It is relatively easy to obtain samples of microbiome DNA
DNA pulled from a mixed sample of bacteria contains DNA from every
species of bacteria in that microbiome
Analysis of this large mixed mass of DNA is called metagenomics
Copyright © 2018 by John Wiley & Sons, Inc. All rights reserved.
Metagenomics
Copyright © 2018 by John Wiley & Sons, Inc. All rights reserved.
Human Microbiome Project
First goal of the project is to characterize the typical
microbiome found in and on the human body
Five areas of the human body that house slightly different
microbiomes:
Nasal passages
Oral cavity
Skin
GI tract
Urogenital tract
Copyright © 2018 by John Wiley & Sons, Inc. All rights reserved.
Human Microbiome Locations
Copyright © 2018 by John Wiley & Sons, Inc. All rights reserved.
Five Aims of the Microbiome Project
1. Develop a reference set of reliable microbial genome
sequences.
2. Identify the complex microbiome communities present in the
human body, looking for a common core of bacterial species.
3. Determine the relationship between disease and changes in the
human microbiome.
4. Develop tools and technology to enable data analysis,
coordination, and cataloging.
5. Examine the ethical, legal, and social aspects of the application
of human microbiome metagenomic applications.
Over 1,530 bacterial species known to colonize human tissues
have had ongoing or completed reference genomes
Copyright © 2018 by John Wiley & Sons, Inc. All rights reserved.
Section 11.2: Our Microbiome Helps
Maintain Homeostasis
Each human has a unique but
predictable microbiome
Each person has a common core
of microbes and then have a
unique set that is determine by
your experiences, interactions
with the environment and your
biochemistry
There are also two types of fungi and
five protozoan species on the list and
are part of our resident flora
Copyright © 2018 by John Wiley & Sons, Inc. All rights reserved.
Microbiomes Development
Newborns pick up bacterial microbiome of the mother at
birth and through feeding via breast milk
The infant develops their own unique microbiome as not all of
the mothers bacteria will transfer in each potential crossing
The infants unique biochemistry will also enhance some
species to grow better than others
Even infants in the NICU has different microbiomes that
developed even in a near aseptic environment of the NICU
Copyright © 2018 by John Wiley & Sons, Inc. All rights reserved.
Laws of Ecology
The bacteria already present in the infants microbiome affect
the ability of newly introduced bacteria to colonize
Simple ecology at work here, if there is an organism in the
environment, living intis required physical space and using the
resources to survive then that environment cannot sustain a
second organism that requires the same parameters.
There can only be one organism per niche but the human
body has many unique niches
The human biome develops over a long period of time, first 23 years the microbiome community will shift dominant
species and alter its composition continuously
All through each stage of life there is changes that occur to
our microbiome
Copyright © 2018 by John Wiley & Sons, Inc. All rights reserved.
Composition of Microbiome Communities
Copyright © 2018 by John Wiley & Sons, Inc. All rights reserved.
Composition of Each Microbiome
Provides Different Benefits
Each of the five areas of the body being analyzed displays a
different composition of core microbes
This is due to different microenvironments
There are overlapping bacterial species in each area
There are unique advantages to the having the different
composition of the microbiome populations
Some produce chemicals that prevent colonization of pathogens
Others secrete toxins that kill specific microbes
Others secrete acids that alter the pH of the area
Provide competition for space and resources, limiting the ability
of a new bacterial species to settle in and take over
Copyright © 2018 by John Wiley & Sons, Inc. All rights reserved.
Normal Skin Microbiota
Copyright © 2018 by John Wiley & Sons, Inc. All rights reserved.
Gut Microbiome
There are hundreds of bacterial species normally present in
the GI tract microbiome
They help protect our gut lining from bacterial infection
They digest compounds that we cannot digest on our own
They produce several B vitamins, Vitamin K, folate, and shortchain fatty acids
Some detoxify compounds we ingest
Others protect against pathogens
There is a connection between our immune system and our
gut microbiome
The two are separated by the lining of the intestines
It is important that our immune system identifies our cells from
infecting cells
Copyright © 2018 by John Wiley & Sons, Inc. All rights reserved.
Gut Microbiome and Immune System
Antigen Presenting Cells are trained to protect against
infection but allow gut microbiomes to flourish
In studies where mice were able to develop an immune system
with out presence of gut microbiomes it was noted that
neutrophil counts remained low even with an infection
Natural Killer Cells couldnt function correctly
Helper T cells and B cells seem to require gut microbiomes for
proper maturation
Gut microbiome seems to be a driving force in the
development of IgA
New studies have shown a connection between gut
microbiome and brain malfunctions.
Copyright © 2018 by John Wiley & Sons, Inc. All rights reserved.
Changes in our Microbiome Can
Result in Disease
Since the gut microbiome plays such
an important role in our health it
seems reasonable to say that
abnormal microbiomes can cause
improper functioning.
Altered proportions of gut bacteria
have been correlated to diabetes,
obesity, and cancer.
Intestinal microbiomes of obese
people seem to carry a higher
percentage of Firmicutes while thinner
people of a higher percentage of
Bacteroidetes.
Copyright © 2018 by John Wiley & Sons, Inc. All rights reserved.
Section 11.3: The Microbiome in
Diagnoses and Treatments
The list of diseases that are related to imbalances in bacterial population has been
growing thanks to research into microbiomes
Diseases can be simple to treat as tooth decay and as difficult to handle as
depression and inflammatory bowel disease and all have a connection to
microbiomes
Medical diagnosis of diseases include microbial dysbiosis
Knowledge of microbiomes is useful in medical diagnosis
Research is occurring looking at the gut microbiome of patients with Celiac
disease and irritable bowel syndrome
The hope is to be able to develop therapies to help restore the gut microbiome and alleviate
the symptoms of the diseases
There is research on C. Difficile and looking at the gut microbiome of patients
suffering from this microbe
Diet plays a role in gut microbiome proportion
Understanding microbiomes has helped with reproductive health
There is a connection between gut microbiome and brain function
Copyright © 2018 by John Wiley & Sons, Inc. All rights reserved.
Diseases and Microbiome Relationship
Copyright © 2018 by John Wiley & Sons, Inc. All rights reserved.
Microbial Dysbiosis
Copyright © 2018 by John Wiley & Sons, Inc. All rights reserved.
Probiotics and Prebiotics
Probiotics are any compound that stimulate the growth of
beneficial microorganisms
Over the counter probiotics contain encapsulated live bacteria
which can survive the stomach acid and dissolve in the small
intestine
The hope is an influx of beneficial microorganisms will help
maintain proper microbiome balance
It is recommended to take prebiotics after a round of
antibiotics to replenish what was destroyed by the antibiotics
Prebiotics are not living organisms, they are non-digestible
carbohydrates that serve as food for normal healthy bacteria.
Copyright © 2018 by John Wiley & Sons, Inc. All rights reserved.
Probiotics Function and Prebiotics Structure
Copyright © 2018 by John Wiley & Sons, Inc. All rights reserved.
Microbiome Applications Beyond Medicine
Forensics have taken an interest in the Human Microbiome
Project
Individual microbiomes differ at both the species and
subspecies level
Identical twins who have identical DNA have different
microbiomes
Profiling bacterial community of the skin microbiome could
serve as a identification marker similar to DNA or fingerprints
Individual identification by microbiome have been used to
match owners with cell phones
The National Institute of Justice is investing the use of
microbiomes for forensic investigations.
Copyright © 2018 by John Wiley & Sons, Inc. All rights reserved.
Antibiotic Resistance
Gut microbiomes are a good
place to look for antibiotic
resistant bacteria
A number of antibiotic resistant
bacteria have been found in gut
microbiomes
This is important to track as it can
help identify how bacteria are
adapting to our available
antibiotics
The Human Microbiome Project
has as many ethical concerns as
the Human Genome Project
Copyright © 2018 by John Wiley & Sons, Inc. All rights reserved.
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