Microbiology discussion… Virus Vs Bacteria ID / Inspection Techniques

Bacteria A bacterium is a microscopic single cell organism Found anywhere: Found anywhere: –Air –Soil –Water –Plants and Animals.

Function: Bacteria There are good & bad bacteria. They have useful functions: There are good & bad bacteria. They have useful functions: –making vitamins –break down garbage The human mouth is home to more than 500 species of Bacteria. The human mouth is home to more than 500 species of Bacteria.

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Culturing Bacteria

The Six “I’s” – Inoculation: Introduce bacteria to culture Incubation: Provide optimal growing conditions. Incubation: Provide optimal growing conditions. Isolation: Separating a “type” of bacteria from the culture Isolation: Separating a “type” of bacteria from the culture Inspection: Stain & study bacteria for shape, size & color Inspection: Stain & study bacteria for shape, size & color *Info Gathering: at this point we will skip this step *Info Gathering: at this point we will skip this step Identification: ID the bacterial Gram + or Gram –; Coccus, bacillus, or sprilla Identification: ID the bacterial Gram + or Gram –; Coccus, bacillus, or sprilla

Gram + or Gram - / Shape

8 The Gram Stain / revisited Microscopic Appearance of CellChemical Reaction in Cell (very magnified view) Step 1 Crystal Violet (primary dye) 2 Gram’ siodine (mordant) 3 Alcohol (decolorizer) 4 Safranin (red dye counterstain) Both cell walls stain with the dye. Dye crystals trapped in cell Crystals remain in cell. Red dye has no effect. Gram (+)Gram (–)Gram (+)Gram (–) Outer wall is weakened; cell loses dye. Red dye stains the colorless cell. No effect of iodine Copyright © McGraw-Hill Education. Permission required for reproduction or display.

Virus Viruses are the simplest of microbes. Viruses are the simplest of microbes. They can be as much as 10,000 times smaller than Bacteria They can be as much as 10,000 times smaller than Bacteria Viruses are made up of DNA or RN A Viruses are made up of DNA or RN A

Viral Shapes

Function Virus When viruses come into contact with the host cell they hijack the cell & release their DNA into the cell. When viruses come into contact with the host cell they hijack the cell & release their DNA into the cell. It can take over immediately or lie dormant for years It can take over immediately or lie dormant for years The host cell does all the work, the viruses just gives the orders The host cell does all the work, the viruses just gives the orders

Culturing Viruses

–Animal viruses may be cultured using a variety of means Whole animals Whole animals Eggs Eggs Tissue culture Tissue culture –Tissue Culture used today for most viruses & vaccines –This involves growing animal cells in flasks using infecting these cells with virus

FYI - Vaccine Selection The viruses used in making flu vaccine are chosen each year on information from the year before The viruses used in making flu vaccine are chosen each year on information from the year before Info is gathered by 94 countries and analyzed by: Info is gathered by 94 countries and analyzed by: –World Health Organization (WHO) –The Centers for Disease Control (CDC): Atlanta, Georgia Atlanta, Georgia London, UK London, UK Melbourne, Australia Melbourne, Australia Tokyo, Japan Tokyo, Japan Experts forecast which viruses are likely to circulate the following season Experts forecast which viruses are likely to circulate the following season

Flu Vaccines The flu vaccine protects against the three main flu strains that research indicates will cause the most illness during the flu season. They are: The flu vaccine protects against the three main flu strains that research indicates will cause the most illness during the flu season. They are: –A/California/7/2009 (H1N1)-like virus –A/Perth/16/2009 (H3N2)-like virus –B/Brisbane/60/2008-like virus

/ A/California/7/2009 (H1N1)pdm09-like virus A/California/7/2009 (H1N1)pdm09-like virus A/Victoria/361/2011 (H3N2)-like virus A/Victoria/361/2011 (H3N2)-like virus B/Wisconsin/1/2010-like virus (from the B/Yamagata lineage of viruses = sub-type of Type B flu – the most common type) B/Wisconsin/1/2010-like virus (from the B/Yamagata lineage of viruses = sub-type of Type B flu – the most common type) an A/California/7/2009 (H1N1)pdm09-like virus; an A/California/7/2009 (H1N1)pdm09-like virus; an A(H3N2) virus antigenically like the cell- propagated prototype virus A/Victoria/361/2011; an A(H3N2) virus antigenically like the cell- propagated prototype virus A/Victoria/361/2011; a B/Massachusetts/2/2012-like (B/Yamagata lineage) virus. a B/Massachusetts/2/2012-like (B/Yamagata lineage) virus.

an A/California/7/2009 ( H1N1)pdm09-like virus an A/Switzerland/ /2013 (H3N2)-like virus a B/Phuket/3073/2013-like virus. ( This is a B/Yamagata lineage virus) – –Some of the flu vaccine is quadrivalent vaccine and also protects against an additional B virus (B/Brisbane/60/2008-like virus). This is a B/Victoria lineage virus.

Parts of the Microscope 22

Magnification power Eye piece: 10X Eye piece: 10X –Low:4X=10 x 4 = 40 –Medium:10X=10 x 10 = 100 –High:40X=10 x 40 = 400

24 The capacity to distinguish or separate two objects Resolution

25 The Purpose of Oil

2 Types of Electron Microscopes Transmission electron microscopes Transmission electron microscopes –(TEM) transparent. 26

27 2 Types of Electron Microscopes Scanning electron microscopes Scanning electron microscopes –(SEM) –3D view. SEM bombards surface of metal- coated specimen with electrons while scanning back and forth

FEW EXAMPLES OF MEDIA The next few slides have some culture media examples The next few slides have some culture media examples You have already seen some of these; but now that you have worked with it, it may mean more to see it again. You have already seen some of these; but now that you have worked with it, it may mean more to see it again.

29 Inspection If a single species is growing in the container, you have a pure culture but if there are multiple species than you have a mixed culture. If a single species is growing in the container, you have a pure culture but if there are multiple species than you have a mixed culture. Check for contaminants (unknown or unwanted microbes) in the culture. Check for contaminants (unknown or unwanted microbes) in the culture.

Physical States of Media Liquid – broth; does not solidify Semisolid – contains solidifying agent Solid – firm surface for colony formation 30

Gram Staining Q6C-gj_UHM Q6C-gj_UHM Q6C-gj_UHM Q6C-gj_UHM