Microbiology

Microbiology is the study of microorganisms. They can be single cellular, multicellular, or acellular. Microbiology incorporates numerous disciplines found within the field of microbiology.
Disciplines are:
• virology
• mycology
• parasitology
• bacteriology
The years from 1857-1914 are called the Golden Age of Microbiology. Some of the famous members found within this field are:Famous Microbiologist

Binomial nomenclature is composed of two italicized words. The first word which is the Genus, is capitalized, and the second word, is the species designation, is in smaller case.

The standard resource for identifying prokaryotes, bacteria, is Bergey’s Manual of Determinative Bateriology.

To be seen without a microscope, it needs to measure about 100 micrometers.  Most microorganisms are smaller than that.  Microorganisms differ between each other in size, structure, habitat, metabolism as well as other characteristics.  Micros are found in Archaea, Bacteria, and Eukarya life domains.

Microbes in the Bacteria & Archaea domains are all prokayotes (lack nucleus).  Cyanobacterium is a prokayotic microorganism.  Eukaryotes are Eukaya (has nucleus)Viruses although are microorganisms do not fall within any of the domains of life.  Virus is acellular.  Peptidoglycan is the ones with cell walls.

Bacteria is a prokaryot because their DNA is not within a true nucleus.  It is found everywhere.  Yeast is a type of fungal microorganism.  Alga is photosynthetic.

Otzi te Iceman was discovered frozen in the Alps.  Scientists believe that he died of Lyme disease.

Pathogens cause disease.  Most are good.  They are named for shape.  Common shapes are spherical (coccus), rod-shaped (bacillus) or curved (spirillum), spirochete, or vibrio.  Bacteria is very versatile.

Archaea unicellular prokaryote.  They are different from bacteria in their evolutionary history as well as numerous other differences.  Their cell walls are psuedopetidoglycan. None of these have been shown to be a pathogen.

Please refer to your book for addition information.

Ebola

 

 

Clinical Symptoms

  • Incubation period—Approximately 43 days
  • Acute illness with rapid onset of fever (104⁰ – 109⁰ F)
  • Sore throat
  • Massive vomiting
  • Diarrhea (3 gallons/day)
  • Poor Kidney Function
  • Poor Liver Function
  • Internal & External bleeding (bleed out of every body opening)
  • Lyses or bursting of Red Blood Cells (RBC)

Treatment

None

Hydrate Slow vomiting & diarrhea Antibodies boost the immune system.  They do not kill viruses

Structure

  • 850 -920 nanometers
  • Single strand of RNA virus
  • Non-Segmented
  • Long thread-like linear molecule
  • Has an extra protein coat

Ebola is a member of the filovirus family (Marburg virus).  Filovirus can cause severe hemorrhagic fever, which symptoms are, fever, vomiting, prostration, petechial hemorrhages, hypotension, and muscle pain.  There are only two members of this virus family (Ebola & Marburg virus).  Ebola have five strains with one Ebola-Reston not causing severe disease in humans.

The Filovirus was discovered in 1967 in Germany and Yugoslavia.  Researchers were analyzing tissue of a green monkey, which had the disease.  Researchers contracted the disease.  This virus was named after where the outbreak occurred Marburg, Germany.  Ebola was first discovered in 1976 in Africa.  There is some evidence that it was originally contracted from bats.  Once humans are infected, it spreads from person to person.

Death rate is 23 to 90%.  To reduce risk of contracting from another human wear PPE, do not have contact with bodily fluids such as blood, and other secretions.  Do not expose yourself to animals out of Africa, which may have the disease.

Currently the medical community is working on a vaccine.  Researchers at Howard Hughes Medical Institute have developed at blood test (Virscan) which will tell doctors the patient complete viral history.

The information provided above was from my Microbiology class.  In writing this blog, the CDC and MedicineNet.com were used as references.  Please check out the video on PBS Frontline called “Ebola”.

Ebola was named after the Ebola River where it was first discovered.  There were two major outbreaks in the 90’s and one in Northwest Africa in 2014.  Death occurs within six days.

In the United States there are only 19 negative pressure beds.  The closest to Louisiana is Atlanta which has four.

Ebola is an enveloped virus meaning it has an extra protein coat.  It is hard for drugs or immunity virus to attach & destroy.

Glycoproteins live on surface of virus.  These glycoproteins are made up of carbohydrate chains called glycans.  There are two types:

  1. GP1-Attachment (which makes it more potent)
  2. GP2-Fusion of host and viral membranes.

 

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Bacterial Morphology

1.      Spherical or round – coccus
2.    Rod or cylinder – bacillus
3.    Spiral – spirillum
4.    Short, curved rod – vibrio
5.     Star shaped – prosthecae

Some prokaryotic (bacterial structures)

1.      Ribosome – make protein
2.    Plasmids – small, circular strand of DNA
3.    Nucleoid – twisted DNA strand
4.    Glycocalyx – layer of polysaccharide lying inside bacterial cell wall
5.     Apendayes-
a.     Pilus
b.    Flagella- consists of a hook for rotation, basal body for anchoring, filament tail for movement

Types of flagella

1.      Monotrichous – single flagella–has tail as one end see example  

2.    Amphitrichous- flagella at both ends—has tail at both ends see example ~

3.    Lophotrichous-tuft of flagella—has tufted tails on bottom see example

4.    Perithrichous-flagella all over—has tufted tails all over see example

Biofilms

Communities or group of microorganisms that attach to the surfaces of animate objects, heart valves, bone tissues, etc and inanimate structures prosthetic in plants, catheters, etc. only effective treatment K removal of infected tissues

Bacterial Colonies

Identify by:

1.      Form shape
2.    Elevation- cross section
3.    Margin-magnified edge of colony
4.    Surface-appearance
5.     Opacity-clear, opaque, translucent
6.    Chromogenesis-color
7.     Consistency
8.    Odor
9.    Emulsifiability

Rudolph Virchow (1821-1902)

1.      Father of modern day public health
2.    Shaped modern day public health
3.    Discovered correlation between cancerous & normal cells, modern day autopsy procedures, hair analysis
4.    Names: leukemia, chordoma, embolism, thrombosis, agenesis, parenchyma, osteoid, spina bifida

Anton von Leeuwenhoek

1.      Father of microbiology
2.    Discovered protists & bacteria
3.    Distilling H2O to kill contaminants
4.    Described bacterial motility
5.     Single-celled (ocular) microscope
6.    Most published author in the Royal Society of Great Britain

William Jaffray

1.      Scotsman
2.    Lived near Stirling
3.    Interest was in eradication of small pox through variolation & family & neighbors using variolation
4.    After 1796, he inoculated 500 nearby families, 2 families chose no inoculation
5.     President of Royal Society gave him equipment to do much more inoculation.
6.    Set up shop in his cottage (1808), travelled throughout Scotland inoculating people.  Took neither payment nor a meal.

Endospores

1.      Dormant form of a bacterium that is formed by reorganized the cytoplasm.
2.    Spore has great resistance to outside influences heat, radiation, dessication, chemicals
3.    Can remain dormant for years   50-100 years
4.    Will germinate if conditions become favorable
5.     Size, shape, & position of an endospore is constant within a species & has taxonomic value

Types of Endospores

1.      Central-middle of cell
2.    Terminal-end of cell
3.    Subterminal-between middle & end

EMB agar (eosin methylene blue)

1.      Selective & differential
2.    Used to isolate gram (-)
3.    Methylene dye in small amounts
4.    Eosin dye responds to changes in pH – colorless to black under acidic conditions
5.     EMB contains lactose & sucrose, but no glucose for energy

Lactose fermenting bacteria (usually enteric) acidify EMB & colonies appear black with green sheen (E. coli, Klebsiella, Enterobacter)

Lactose non-fermenters are translucent to pink (salmonella, shigella, and pseudomonas

The EMB selects for growth of gram (-) bacteria & differentiates between genera of gram (-)

We must be willing to get rid of the life we have planned so as to have the life that is waiting for us.  Joseph Campbell

 

 

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