FAQ: How do you identify colony morphology?

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. A swab from a bin spread directly onto nutrient agar. Colonies differ in their shape, size, colour and texture.

How do you identify a bacterial colony?

Of course, the best practice to identify a colony by viewing it under a microscope, but a good primary indicator is a bacterial colony’s aspects visible by eye on the agar plate. Aspects like size, separation from other colonies, circularity vs.

What are the signs of a morphology bacterial colony?

8: Bacterial Colony Morphology


How would you describe a colony characteristics?

Characteristics of a colony such as shape, edge, elevation, color and texture. When recording colony morphology, it is important to also record color, optical properties (translucence, sheen) and texture (moist, mucoid or dry).

How do you identify morphology?

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. A swab from a bin spread directly onto nutrient agar. Colonies differ in their shape, size, colour and texture.

How do you identify bacterial culture?

During a bacteria culture test, a sample will be taken from your blood, urine, skin, or other part of your body. The type of sample depends on the location of the suspected infection. The cells in your sample will be taken to a lab and put in a special environment in a lab to encourage cell growth.

How would you describe a colony in microbiology?

In microbiology, a “colony” is a group of bacteria, fungi, and other microorganisms grown on a solid agar medium. The cells plated on this medium grow to form a mass, which can then be duplicated for further use in the lab.

How would you determine whether a colony is a contaminant or a real bacterial culture?

1. Perform Gram staining and look at the morphology of the bacterial cells, if contaminated more than one cell type shall be visible. 2. Streak the culture on a suitable agar based medium and observe color and type of cfus.

What do colonies look like in microbiology?

Bacterial colonies are frequently shiny and smooth in appearance. Other surface descriptions might be: veined, rough, dull, wrinkled (or shriveled), glistening.

How do you identify a colony?

Colony morphology can sometimes be useful in bacterial identification. Colonies are described on the basis of size, shape, texture, elevation, pigmentation, and effect on growth medium. In this blog post, you will find common criteria that are used to characterize the bacterial growth.

What are the categories of colony morphology?

Colony morphological characteristics may be viewed with the naked eye, a hand lens, a stereo (dissecting) microscope, or a colony counter (Fig. 2.3). The seven basic categories include colony size, shape, margin (edge), surface, elevation, texture, and optical properties (Fig.

What is the relationship between morphology and colony?

Morphology of colonies can be defined as their color, shape, edge and elevation. These features are observed with the naked eye by looking at the colony itself. However, cellular morphology shows the difference of the individual cells that is seen under the microscope.

How do you identify bacterial colonies in a Petri dish?

Bacterial Colony Description – YouTube

Why is it important to determine colony cultural characteristics?

It is important in microbiology to determine the characteristics of bacteria such as colonies, the rapidity of their development, their action upon the medium, size, shape, and appearance to identify the bacteria.

How reliable is colony morphology?

Colony morphology was found to be a reliable method of screening for different enterococcal strains in the clinical samples tested. In every case, the four representative colonies of each colony type were shown to be indistinguishable by antibiogram, biochemical profile, and PFGE.

What are 3 methods used to identify bacteria?

Traits that can be valuable aids to identification are combinations of cell shape and size, gram stain reaction, acid-fast reaction, and special structures including endospores, granules, and capsules. Traits that can be assesed with the naked eye.

How do you identify a bacteria?

Bacteria are identified routinely by morphological and biochemical tests, supplemented as needed by specialized tests such as serotyping and antibiotic inhibition patterns. Newer molecular techniques permit species to be identified by their genetic sequences, sometimes directly from the clinical specimen.

How do we identify unknown organisms?

A dichotomous key is a common tool used by biologists and other naturalists to categorize an unknown organism. This “key” is a series of questions or statements asking about a specific characteristic of the organism. Once a question is answered, it leads to another question.

Would cultural characteristics like colony morphology?

Would cultural characteristics like colony morphology be of value to a clinical microbiologist? How could they be used? Yes, it would be of value. It helps identify bacteria so that the appropriate treatment can be used.

How does a colony develop microbiology?

On a colonized solid surface, such as the various growth media used to culture microorganisms , each colony arises from a single microorganism. The cell that initially adheres to the surface divides to form a daughter cell. … This pile, now large enough to be easily visible to the unaided eye, represents a colony.

What is the difference between colony morphology and cellular morphology?

cellular morphology shows the difference of the individual cells that is seen under the microscope. … Morphology of colonies can be defined as their color, shape, edge and elevation. These features are observed with the naked eye by looking at the colony itself.

How would you determine whether a colony is a contaminant?

A colony PCR is an experiment whereby a specific DNA sequence is amplified by a heat stable DNA polymerase enzyme. The DNA which is amplified is specified by oligonucleotides called primers. If the colony does not amplify using primers specific for the desired microbe it means that the colony is a contaminant.

How do you determine if a culture is contaminated?

Bacterial contamination is easily detected by visual inspection of the culture within a few days of it becoming infected,

  1. Infected cultures usually appear cloudy (i.e., turbid), sometimes with a thin film on the surface.
  2. Sudden drops in the pH of the culture medium is also frequently encountered.

How do you identify cultural contamination?

If your media contains phenol red: look for changes in the color of your media as this indicates pH changes. If it starts to go orange/yellow, you may have a problem (either contamination or you need to replenish your cell’s media supply more frequently). Look for signs of turbidity or cloudiness of the media.

What causes colony morphology?

Bacteria grow tremendously fast when supplied with an abundance of nutrients. Different types of bacteria will produce different-looking colonies, some colonies may be colored, some colonies are circular in shape, and others are irregular. … are termed the colony morphology.

How would you describe colonies on blood agar?

Colonies typically are surrounded by a green, opaque zone. Streptococcus pneumoniaeand Streptococcus mitis are a-hemolytic (the picture in the middle below shows the a-hemolysis of S. mitis). If no hemolysis occurs, this is termed gamma-hemolysis.

What is an example of a colony?

An example of a colony was Massachusetts under British rule during the 17th and 18th centuries. An example of a colony is a group of ants. A group of the same kind of animals, plants, or one-celled organisms living or growing together.

What is the colony morphology of E coli?

Traditionally, the colony morphology of Escherichia coli is identified as either a rough or a smooth form. The two forms are readily distinguished, as the colonies of the former are rough, flat, and irregular and colonies of the latter are smooth, high, and circular.

Which of the following characteristics of colony indicate elevation?

The vertical growth or elevation of the colony, another identifying characteristic, is assessed by tilting the agar plate to the side and is denoted as flat, raised, convex, pulvinate (very convex), umbilicate (having a depression in the centre) or umbonate (having a bump in the centre).

What is microbiology morphology?

morphology, in biology, the study of the size, shape, and structure of animals, plants, and microorganisms and of the relationships of their constituent parts.

What are 5 characteristics of bacterial colony morphology quizlet?

Terms in this set (7)

Size,shap,color,texture,elevation,and margin.

How do you read a culture plate?

How to Read Culture Plates – YouTube

Why is it important to identify different colony shapes edges etc?

Why is it important to be able to identify different colony shapes, sizes, edges, etc.? A way to learn and identify the name of the bacteria. How does streaking a plate result in obtaining a pure culture? … Nutritional for bacteria to grow while INHIBITING other bacteria growth.

What are mucoid colonies?

Mucoid: Bacterial colonies that appear moist and sticky (resembling mucus). Colony metallic. Odor of grapes. No. No.

What is meant by the term Colonial morphology?

Introduction. Colony morphology is the visual culture characteristics of a bacterial colony on an agar plate. Observing colony morphology is an important skill used in the microbiology laboratory to identify microorganisms.

How would you describe fungal colony morphology?

Fungal colonies are the visible masses of fungi on solid media. Bacterial colonies appear as tiny and creamy dots on the agar surface. Fungal colonies appear as powdery or filamentous moulds on the agar surface. Bacterial colonies grow rapidly on agar media.

What colony characteristics can be used for differentiation?

Useful colony characteristics for differentiation of bacterial species include size, color, shape, texture, opacity, and odor.

How does temperature affect colony morphology?

Colonial morphology may also be affected by the temperature at which the bacteria is incubated. Some bacteria grow better at body temperature and grow weakly at room temperature, or vice versa. … The presence of other organisms can interfere with bacterial growth.

How do you identify bacteria under a microscope?

Upon viewing the bacteria under the microscope, you will be able to identify the bacteria based on a wide variety of physical characteristics. This mainly involves looking at their shape and size. There are a wide variety of different shapes, yet the three main types are cocci, bacilli, and spiral.

What 4 characteristics are used to identify bacteria?

When identifying bacteria in the laboratory, the following characteristics are used: Gram staining, shape, presence of a capsule, bonding tendency, motility, respiration, growth medium, and whether it is intra- or extracellular.

What tests are used to identify bacteria?

Tests used to identify Gram Positive Bacteria

  • Catalase Test.
  • Mannitol Salt Agar (MSA)
  • Blood Agar Plates (BAP) Streak-stab technique.
  • Taxos P (optochin sensitivity testing)
  • Taxos A (bacitracin sensitivity testing)
  • CAMP Test.
  • Bile Esculin Agar.
  • Nitrate Broth.

What are two methods of identifying bacteria?

Among the techniques we use are:

  • DNA sequencing – to identify bacteria, moulds and yeasts.
  • Riboprinter analysis – for bacterial identification and characterisation.
  • Repeat–based polymerase chain reaction – for assessing the similarity of microorganisms.
  • Rapid pathogen confirmation by polymerase chain reaction.