Introduction Lecture 1 Flashcards
Microbiology is the study of single cell organisms such as?
bacteria, archaea, fungi, parasites, viruses
single celled organisms reproduce?
independently and/or in hosts
what do we study within microbiology?
microorganisms as cells, foundationof all biological sciences, thir natural environments, extent of microbial life, impact of on humans
microbiology has two branches of inquiry?
1) understand basic processes of microbes (excellent models for understanding cellular processes in unicellular and multi-cellular organisms)
2) how to apply that understanding to benefit of humans (medicine, agriculture, industry)
microbial systematics
classification and nomenclature of microbes
microbial physiology
nutrition and metabolism
microbial biochemistry
enzymes and chemical reactions in cells
microbial genetics
genes, heredity and genetic variation
molecular biology
DNA to RNA to Protein
virology
study of viruses
genomics
genome sequencing and comparative analysis
microbial ecology
diversity and activity in natural habitats
medical microbiology
study of microbial diseases
microbial disease subdiscipline of medical microbiology
- study of infectious disease
- many pathogenic organisms produce several outcomes in disease
- some infectious diseases are caused by organisms coming from exogenous microbial sources (from outside the body)
- other infectious diseases are caused by organisms from an endogenous microbial source (already part of the microbial flora)
immunology subdiscipline of medical microbiology
- innate and adaptive immune systems that control microbial infections
- immune responses to both normal flora and exogenous microbes
- exuberant immune responses to the microbe sometimes causes the disease outcomes AND sometimes a disease NOT associated with the original infection
- most pathogens actively evade the immune response in some way
diagnostic microbiology subdiscipline of medical microbiology
- technology for detection and diagnosis of disease causing organism
- identification of chemotherapeutic agents for treatment (antimicrobials)
- measurement of immune responses to the disease causing organism- sometimes this is the only way to know if an organism has infected a person
why is microbiology in a dental curriculum?
there are ~600 species of bacteria that could reside in the human oral cavity (and 1 archaea species)
what are caries? caused by? increased when/why?
disease where cavitites develop on surface of the tooth
- caused by streptococcus mutans and streptococcus sobrinus
- drastic increase around 1850 with revolution and new largely sugary diets
what is periodontitis? caused by?
chronic inflammation at the gingiva and bone destruction around the tooth
*caused by porphyromonas gingivalis, fusobacterium nucleatum, and actinomyecetes actinomyeticomitans
what is the 6th most prevalent heath condition in the world and one of the most ancient diseases of mankind?
periodontitis (found in mummies in pyramids)
what is oral thrush? caused? associated with?
inflammation in the mouth caused by the overgrowth of fungus Candida albicans (which is normal in the oral cavity but has overgrowth and response issue)
*associated with immune deficiencies
what is endodontits? caused by?
inflammation at the root of the tooth
*caused by Porphyromonas endodontalis, and Enterococcus faecalis
what is Kaposi’s Sarcoma? caused by?
cancer at the endothelium of mouth (can be on skin and other mucosal surfaces); sometimes caused by a combination of infection with Human Herpes Virus 8 and immune deficiency
Lymphoma of head and neck? caused?
caused by Epstein Barr Virus
*this virus infects over 90% of all humans; however, in some people it leads to lymphomas
what is oral squamous cell carcinoma?
cancer at epithelium of mouth caused by Human Papilloma virus (HPV)
*also caused cervical cancer
Pneumonia? caused by?
lung infection caused by Streptococcus pneumoniae
Oral Absesses? caused by?
deep tissue infection caused by Stephylococcus aureus (epithelia)
Tuberculosis? caused by?
lung infection caused by bacteria called Mycobacterium tuberculosis (2 billion people affected)
main cause of death from 1900 to today?
1990= 30% of deaths worldwide occured in children due to infectious diseases 2017= heart disease, diabetes, stroke, alzheimer's, suicide
the greatest achievemnt of microbiology was the dramatic decrease in mortality from infectious diseases due to?
better sanitation, better nutrition, antibiotics, and vaccines
microorganisms
are central to the biosphere, nothing we can do to avoid them
microorganisms in or on our body outnumber our own cells by? bacteriophages outnumer microorganisms?
- *micro: human =at least 3:1
* *bacteriophages: mirco = 10:1
bacteriophages?
viruses that infect the microorganisms of body
endocymbiosis example
all of our cells have mitochondria which IS a bacteria that cannot survive without human cell or vice versa
two types of microorganisms? our cells are
prokaryotic and eukaryotic
*we have Eukaryotic
4 classes of macromolecules in EVERY cell including microbial cells? examples
1) proteins -composed of amino acids (lipoproteins, glycoproteins)
2) nucleic acids -composed of nucleoties (RNA and DAN)
3) lipids- composed of fatty acids (phospholipids)
4) polysaccharides- composed of sugars (glucan and fructan)
5 key bacterial structures?
1) cytoplasmic cell membrane
2) cytoplasm
3) nucleoid
4) ribosomes
5) cell wall (not the same as membrane)
cytoplasmic cell membrane
- barrier that separates the inside of the cell from the outsides and has transport
- contains no steroids
- responsible for electron transport and energy production
- contains transport proteins, enzymes, secretion devices and shape determining proteins
cytoplasm
- fluid that fills cells for most of the metabolic an d reproductive events
- contains the chromosome, mRNA, ribosomes, proteins, metabolites
neucleoid
non-membrane bound area with single double stranded circular DNA chromosome
ribosomes
30S + 50S subunits form a 70S ribosome
*“machinary” for protain synthesis and cell growth
cell wall
- present in nearly all microbes, confers structural strength
- contains peptidoglycan in bacteria
- archaea contain psuedoglycans
- yeast often contain glucans
- mycoplasma bacteria are devoid of cell wall (so they need to be in a safe environment to live, animal)
- gram negative bacteria have a cell wall surrounded by an outer membrane
yeast is eukaryotic or prokaryotic?
Eukaryota
mycoplasma bacteria are devoid of?
cell walls! so they need to be in a safe environment to live, animal
3 most important microbiologists?
1) Anton ven Leeuwenhoek
2) Louis Pasteur
3) Robert Koch
Anton van Leeuwenhoek
first microbiologist! first to describe bacteria using a microscope; called them ‘little animals’
*thought they grew out of nothing from spontaneous generation
the field of microbiology was unable to develop until?
Anton van Leeuwenhoek constructed microscopes that allowed scientists to see organisms too small to be seen with the naked eye
the science of mircobiology did not exist until the invention of?
the microscope that can see bacterial cells
understanding cellular structures of microbes did not exist until the invention of?
electron microscope
Louis Pasteur
- discovered that living organisms discriminate between optical isomers
- discovered that alcoholic fermintation was a biologically mediated process (originally thought to be pureply chemical)
- disproved theory of spontaneous generation by Anton van Leeuwenhoek which led to the development of methods for controlling the growth of microorganisms =PASTEURIZATION
- developed vaccines for anthrac, fowl cholera, and rabies
living organisms can take what optical isomer?
take the D but not the L
alcoholic fermentation is mediated how?
biologically
spontaneous generation
- hypothesis that living organisms can originate from nonliving matter.
- Pasteur disproved this idea through a famous experiment that showed that a sterile media could be contaminated with and grow bacteria only if the sterile media is exposed to air that contains bacteria
spontaneous generation
- hypothesis that living organisms can originate from nonliving matter.
- Pasteur disproved this idea through a famous experiment that showed that a sterile media could be contaminated with and grow bacteria only if the sterile media is exposed to air that contains bacteria
Robert Koch
- Discovered that microorganisms were the cause of the disease called Anthrax.
- On the evening of March 24, 1882, Robert Koch announced the infectious cause of tuberculosis to a crowded room at the Berlin Physiological Society
- Discovered the bacterial colony
- Developed method to grow isolated coloniesof bacteria
- Developed the scientific method to prove that a suspected microorganism causes a disease: Koch’s postulates
define KOCH’s Postulates
an approach that Koch developed to determine which microorganism causes a disease
describe steps of KOCH’s Postulates
1) suspected pathogen must be present in ALL cases of the disease and absent from heathy animals –Microscopy & staining
2) the suspected pathogen must be grown in pure culture –laboratory sultures
3) cells from a pure culture of the suspected pathogen must cause disease in a heathy animal –experimental animals
4) the suspected pathogen must be reisolated and shown to be the same as the original –laboratory reisolation & culture
