Is Serratia marcescens hemolytic?

Background: Serratia marcescens is a gram-negative

gram-negative

Gram-positive bacteria are bacteria classified by the color they turn in the staining method. Hans Christian Gram developed the staining method in 1884. The staining method uses crystal violet dye, which is retained by the thick peptidoglycan cell wall found in gram-positive organisms.

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bacterium and often causes nosocomial infections. There have been few studies of the virulence factors of this bacterium. The only S. marcescens hemolytic and cytotoxic factor reported, thus far, is the hemolysin

hemolysin

Hemolysins can be secreted by many different kinds of bacteria such as Staphylococcus aureus, Escherichia coli or Vibrio parahemolyticus among other pathogens. We can take a look at the bacterium Staphylococcus aureus as a specific example of pore-forming hemolysin production.

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Hemolysin - Wikipedia

ShlA.

What type of hemolysis is Serratia marcescens?

S. marcescens produces two types of hemolysins: contact-dependent hemolysin and extracellular hemolysin [16]. The ShlA hemolysin has cytolytic and contact-dependent hemolytic activity, but little is known about the S. marcescens secreted hemolysin.

Why does Serratia marcescens turn red?

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

What is unique about Serratia marcescens?

It is resistant to many antibiotics traditionally used to treat bacterial infections, such as penicillin and ampicillin [9]. This is due to all of Serratia marcescens' characteristics; unique membrane (LPS) as a Gram-negative bacteria, the ability to survive in aerobic and anaerobic conditions, and its motility [10].

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.

Osmosis | Serratia Marcescens

Is Serratia marcescens aerobic or anaerobic?

Ok, now Serratia marcescens is motile and also facultative anaerobic which means it can survive in both aerobic and anaerobic environments.

What is the importance of Serratia marcescens?

Serratia marcescens is an important cause of nosocomial infections in both human and veterinary medicine. In human patients it is often linked to intravenous drug use. The organism has a tremendous ability to survive in the environment and may contaminate and remain viable in disinfectant solutions.

Why does Serratia marcescens change color?

Pigmentation of Serratia marcescens depends on the composition of the cultivation medium. The cultures grown on glycerol-peptone medium and on the medium with acetate are red and yellow (yellowish orange), respectively, with the color depending on the ambient pH.

Why does Serratia marcescens turn white?

Marcescens produces a red pigment (i.e. colonies are red) when grown at 24-30°C. Mutations in the bacterial DNA for the red pigment will cause the colonies to turn white (they don't make the red pigment) or pink (they make less of the red pigment).

What color is Serratia marcescens?

Serratia marcescens is red at 25 C and white at 37 C.

What does Alpha hemolysis indicate?

Alpha hemolysis is a greenish discoloration that surrounds a bacterial colony growing on the agar. This type of hemolysis represents a partial decomposition of the hemoglobin of the red blood cells.

Does Serratia marcescens grow on EMB agar?

Eosin methylene blue agar (EMB) is a differential and selective media that supports the growth of gram-negative bacteria, including Escherichia coli and S. marcescens.

Does Serratia marcescens grow on MacConkey Agar?

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.

Is Serratia marcescens positive for oxidase?

The Biochemical identification of Serratia marcescens showed that bacteria were Gram –ve, Rod, Catalase positive, oxidase negative, lactose non- fermenter, motile, Indole negative, citrate utilization positive, TSI y/y, DNase positive and Urease negative as shown in table (1) as [27].

Is S. marcescens catalase negative?

Gram staining showed that they were gram negative bacilli which were catalase positive and oxidase negative. The organisms were motile and they showed DNAse and gelatinase production.

Is Serratia marcescens Lipase positive?

Most strains of Serratia marcescens produced both enzymes while most strains of Serratia liquefaciens exhibited strong lipase but only a minor phospholipase activity.

Is Serratia marcescens a Thermophile?

The mesophile Serratia marcescens grows normally in the temperature range of 20" to 37" C; its lower limit of growth is 10". Recently, a red-pigmented organism, which grows only in the temperature range 0" t6 19" C, was isolated froin flounder's eggs (1).

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.

What are the virulence factors of Serratia marcescens?

Serratia species secrete several virulence factors, such as DNase, lipase, gelatinase, hemolysin, proteases, chitinase, chloroperoxidase, and multiple isozymes of alkaline phosphatase, and also produce carbapenem antibiotics, a red pigment named prodigiosin (Figure 29), and biosurfactants.

What does Serratia marcescens ferment?

S. marcescens has a complex cell wall and uses peritrichous flagella to move. Its colonies are smooth and moist on non-selective media. The bacterium reduces nitrates, is oxidase negative, and uses acid production to ferment glucose.

Is Serratia marcescens antibiotic resistant?

Aim: Serratia marcescens clinical isolates are increasingly resistant to antibiotics. Therefore, the treatment of infections caused by S. marcescens becomes difficult.

Is Serratia marcescens prokaryotic or eukaryotic?

We focused on such plasticity in a model prokaryotic organism—the bacterium Serratia marcescens, whose natural coloration greatly facilitates in vivo observation of developing multicellular structures. Bacteria cover an admirable range of multicellular life forms, even within a single species or strain.