Question

Directions: There are two parts for this lab. The first part is working with the Microscope slides. The second part is working with media.

Task 1 – Bacteriology Survey Microscope Slides
Directions: There are eight different bacterium you need to research.
Below is the following bacterium you need to describe and include an image for.
•   Streptococcus
•   Treponema
•   Neisseria gonorrhoeae
•   Klebisella pneumonia
•   Unstained Bacillus
•   Bacillus cereus
•   Clostridium tetani
•   Escherichia coli

Task 2 – Observing Media in a Petri Dish
Directions: Below are examples of media that has been plated and share descriptions of each. Please answer the questions under each image description.
Observing bacteria in a petri dish
Students should examine cultures in containers, which have been taped and closed. Colony morphology is a method that scientists use to describe the characteristics of an individual colony of bacteria growing on agar in a Petri dish. It can be used to help to identify them.
Different types of bacteria will produce different-looking colonies, some colonies may be colored, some colonies are circular in shape, and others are irregular. A specific terminology is used to describe common colony types. These are:

•   Form - What is the basic shape of the colony? For example, circular, filamentous, etc.
•   Size – The diameter of the colony. Tiny colonies are referred to as punctiform.
•   Elevation - This describes the side view of a colony. Turn the Petri dish on end.
•   Margin/border – The edge of a colony. What is the magnified shape of the edge of the colony?
•   Surface - How does the surface of the colony appear? For example, smooth, glistening, rough, wrinkled or dull.
•   Opacity - For example, transparent (clear), opaque, translucent (like looking through frosted glass), etc.
•   Colour - (pigmentation) - For example, white, buff, red, purple, etc.
Each distinct colony represents an individual bacterial cell or group that has divided repeatedly. Being kept in one place, the resulting cells have accumulated to form a visible patch. Most bacterial colonies appear white or a creamy yellow in colour, and are fairly circular in shape.

FORM Circular Irregular Filamentous Rhizoid ELEVATION Raised Convex Flat umbonate Crateriform MARGIN Entire Undulate Filiform Curled Lobate



A swab from a bin spread directly onto nutrient agar.
Colonies differ in their shape, size, colour and texture. Can you count how many different colony types there are? Use the diagrams on colony morphology to help you interpret your plate.

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A cough that was aimed directly onto nutrient agar.
Colonies differ in their shape, size, colour and texture. Can you count how many different colony types there are? Use the diagrams on colony morphology to help you interpret your plate.

A sample of liquid soap spread onto nutrient agar
A sample of liquid soap spread onto nutrient agar and a swab from a bar of solid soap also spread onto nutrient agar. Soaps are not designed to kill microbes. They help to wash them of your skin, better than water alone. Why do you think that the solid soap (kept by the sink and handled regularly) had more bacteria living on it than the liquid soap (kept in a dispenser, so not handled) which had none? You may be interested to know that while soaps do not kill microbes they can be quite a good medium for them to grow on!

A streak plate to isolate single colonies of a specific bacterium
A streak plate to isolate single colonies of a specific bacterium found living on a sample of paper. Paper is not a good object for bacteria to live on as it cannot sustain their growth. The bacteria found on the paper are known as transient i.e. they are just passing the time until a better place to live comes along. Handling the paper would transfer the resident bacteria from a person's hand to the paper.
Based on the examples provided, which stood out to your the most or caught your attention I should say? How do these images play an important part in understanding microbes within microbiology?

Answer 1

Task 1

1. Streptococcus is a genus of Gram-positive coccus or spherical bacteria that belongs to the family Streptococcaceae, within the order Lactobacillales, in the phylum Firmicutes. Cell division in streptococci occurs along a single axis, so as they grow, they tend to form pairs or chains that may appear bent or twisted.

2. Treponema is a genus of spiral-shaped bacteria. The major treponeme species of human pathogens is Treponema pallidum, whose subspecies are responsible for diseases such as syphilis, bejel, and yaws. Treponema carateum is the cause of pinta.
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3. Neisseria gonorrhoeae, also known as gonococcus (singular), or gonococci (plural) is a species of Gram-negative diplococci bacteria isolated by Albert Neisser in 1879​​​​​​

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4. Klebsiella pneumoniae is a Gram-negative, non-motile, encapsulated, lactose-fermenting, facultative anaerobic, rod-shaped bacterium. It appears as a mucoid lactose fermenter on MacConkey agar.

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5. Bacillus (Latin "stick") is a genus of Gram-positive, rod-shaped bacteria, a member of the phylum Firmicutes, with 266 named species. 6. Bacillus cereus is a Gram-positive, rod-shaped, facultatively anaerobic, motile, beta-hemolytic, spore forming bacterium commonly found in soil and food. The specific name, cereus, meaning "waxy" in Latin, refers to the appearance of colonies grown on blood agar.7. Clostridium tetani is a common soil bacterium and the causative agent of tetanus. When growing in soil, C. tetani is rod-shaped and up to 2.5 μm long. However, when forming spores, C. tetani becomes substantially enlarged at one end, resembling a tennis racket or drumstick.8. coli (Escherichia coli), is a type of bacteria that normally lives in your intestines. It's also found in the gut of some animals. Most types of E. coli are harmless and even help keep your digestive tract healthy. But some strains can cause diarrhea if you eat contaminated food or drink fouled water.