What is the colony morphology of Serratia marcescens?

Gram stain of Serratia marcescens shows typical "short rod" morphology. Due to limits of resolution using a light microscope, single rods often resemble pairs of cocci or coccoidal cells.

What is the arrangement of Serratia marcescens?

Serratia marcescens is a gram-negative rod-shaped facultatively anaerobic bacterium that is extremely motile. An S. marcescens gram stain shows short, pink-colored dots, as seen below. Rod-shaped bacteria, bacilliform bacteria or bacilli describe the typical shape of Serratia marcescens.

What color are Serratia marcescens colonies?

DNase agar, which contains DNA, and DTC agar, which contains cephalothin (to which most strains of Serratia are resistant), are also used for isolation. On blood agar and some other media, S. marcescens produces red colonies. As the colonies grow, the colour intensifies.

What shape is the bacteria Serratia marcescens?

Serratia marcescens is a Gram-negative, facultatively anaerobic, rod-shaped bacterium belonging to the family Enterobacteriaceae.

What is the texture of Serratia marcescens?

For comparison purposes, after 3 days of incubation at 30°C, the S. marcescens MG1 parental wild-type colonies were ∼4 mm in diameter, had a “non-sticky-to-touch” colony texture, and had a rough or grainy appearance (Fig.

Osmosis | Serratia Marcescens

What is the colony morphology of Staphylococcus aureus?

S. aureus is a facultatively anaerobic, Gram-positive coccus, which appears as grape-like clusters when viewed through a microscope, and has round, usually golden-yellow colonies, often with hemolysis, when grown on blood agar plates.

What is the morphology of Staphylococcus epidermidis?

Cellular morphology and biochemistry

Staphylococcus epidermidis is a very hardy microorganism, consisting of nonmotile, Gram-positive cocci, arranged in grape-like clusters. It forms white, raised, cohesive colonies about 1–2 mm in diameter after overnight incubation, and is not hemolytic on blood agar.

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.

How would you describe the arrangement of bacteria?

Bacteria are classified into five groups according to their basic shapes: spherical (cocci), rod (bacilli), spiral (spirilla), comma (vibrios) or corkscrew (spirochaetes). They can exist as single cells, in pairs, chains or clusters.

What makes Serratia marcescens unique?

Serratia marcescens has a unique ability to produce extracellular enzymes (28). Several such enzymes have been shown to have the ability to degrade chitin, a substance which mainly comprises fungal cell walls (28).

What is cellular arrangement?

While arrangement refers to the groupings of individual cells, morphology describes the appearance of groups of bacteria, or colonies. Colony shapes can be round, irregular, filamentous or curled.

What is the colony morphology of Bacillus subtilis?

Bacillus subtilis is a typical germ, which is rod-shaped and Gram-positive. When cultured on ordinary nutrient agar, the morphology circular colony of this bacteria is rough, opaque, fuzzy white or slightly yellow with jagged edges [1, 7].

Is Serratia marcescens Gram-positive or negative?

Serratia species are gram-negative bacilli of the Enterobacteriaceae group of bacteria, although they are not a common component of healthy human fecal flora.

What Agar does Serratia marcescens grow on?

Culture: S. marcescens grows well on blood agar and MacConkey agar. It is non-lactose fermenting. Some strains produce a red pigment in nutrient agar, tryptic soy agar, MacConkey agar at room temperature.

What is the morphology of Staphylococcus?

Morphology: Spherical cocci; often forming regular and "grape-like" clusters. They occur singly, in pairs, tetrads, and short chains.

How can colonies be used to identify bacteria?

Observing colony morphology is an important skill used in the microbiology laboratory to identify microorganisms. Colonies need to be well isolated from other colonies to observe the characteristic shape, size, color, surface appearance, and texture. Another important characteristic of a bacterial colony is hemolysis.

What's the difference between Staphylococcus aureus and epidermidis?

The key difference between epidermidis and aureus is that Staphylococcus epidermidis is a non-haemolytic bacterium while Staphylococcus aureus is a haemolytic bacterium. Epidermidis and aureus are species names of two bacteria in the bacterial genus Staphylococcus.

What is the colony colour of Staphylococcus aureus?

S. aureus produces the yellow pigment staphyloxanthin and characteristic gold-colored colonies are formed on all rich media including tryptic soy agar (TSA) at 37°C, brain heart infusion (BHI) agar and Luria Bertani (LB) agar.

What is colony Staphylococcus aureus?

Staphylococcus aureus forms giant colonies on soft-agar surfaces, which is called colony-spreading. In the present study, we searched for host factors that influence S. aureus colony-spreading activity. The addition of calf serum, porcine serum, or silkworm hemolymph to soft-agar medium stimulated S.

Why does S. aureus look different than S epidermidis on MSA?

On MSA, only pathogenic Staphylococcus aureus produces small colonies surrounded by yellow zones. The reason for this color change is that S. aureus have the ability to ferment the mannitol, producing an acid, which changes the indicator color from red to yellow.

Is Serratia marcescens convex?

Results from this study indicated that there were no significant differences between the phenotypic and molecular characteristics of the S. marcescens strains from the cactus plant and silkworms. Both two strains formed red, smooth, convex, entire and round colonies on nutrient agar.

Why is Serratia marcescens red?

Serratia marcescens is a gram-negative, facultatively-anaerobic bacterium and opportunistic pathogen which produces the red pigment prodigiosin.

Why is it important to determine colony cultural characteristics?

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.