Is Serratia a lactose fermenter?

Serratia Species

Of the many species in the genusSerratia, Serratia marcescens is the one most commonly isolated from human infections, andSerratia liquefaciens is occasionally grown. Serratia strains are motile, rarely ferment lactose, and produce an extracellular DNase.

What type of fermentation is carried out by Serratia spp?

Butanediol fermentation is carried out by members of the genera Enterobacter, Erwinia, Hafnia, Klebsiella, and Serratia.

Can Serratia marcescens grow on MacConkey agar?

Streak plate of Escherichia coli and Serratia marcescens on MacConkey agar. Both microorganisms grow on this selective media because they are gram-negative non-fastidious rods.

What agar does Serratia grow on?

CT agar supports the growth of all Serratia strains tested but few other bacteria.

What type of organism is Serratia?

Serratia marcescens is an opportunistic, gram negative, nosocomial pathogen which belongs to family, Enterobacteriaceae. It was discovered by Bizio, an Italian pharmacist, in 1819, when he identified it as a cause of the bloody discolouration on cornmeal mush.

USMLE LACTOSE FERMENTERS / NON FERMENTERS

Does Serratia marcescens ferment glucose?

Serratia marcescens was able to metabolize mannitol to produce acid, but gas was not produced. Glucose – Positive for the fermentation of glucose to produce acid, but negative for the production of gas.

Is Citrobacter a lactose fermenter?

Citrobacter spp. are late lactose fermenters and they grow on MacConkey Agar. Its cultivation is 24 hours, aerobic atmosphere is at 37°C and approximately 20% of clinical isolates are lactose negative.

Is Yersinia pestis a lactose fermenter?

pestis will grow as small, non- lactose fermenting colonies on MAC or EMB agar.

Is Serratia marcescens beta hemolytic?

Serratia marcescens is a gram-negative 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 ShlA.

What does Serratia marcescens look like on agar?

Serratia marcescens. Medium-sized colonies that appear buff in colour on Blood Agar. The bacteria produce a red pigment which is easily seen when grown on blood-free media such as nutrient agar or Kings agar B. This culture has been incubated at 30°C.

Does Serratia marcescens ferment mannitol?

Most pathogenic staphylococci, such as Staphylococcus aureus, will ferment mannitol. Most non-pathogenic staphylococci will not ferment mannitol. The Staphylococcus aureus ferments mannitol and turns the medium yellow. The Serratia marcescens does not grow because of the high salt content.

Are E. coli lactose fermenters?

E. coli are facultative anaerobic, Gram-negative bacilli that will ferment lactose to produce hydrogen sulfide.

Is Serratia marcescens aerobic?

Serratia marcescens is short and rod shaped. It is a facultative anaerobe, meaning that it can grow in either the presence of oxygen (aerobic) or in the absence of oxygen (anaerobic).

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.

Is marcescens a Mesophile?

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 hemolysis is Serratia marcescens?

Background: Serratia marcescens is a gram-negative 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 ShlA.

Why does Serratia marcescens produce a red pigment?

The bacterium has a protein that causes a reaction that is particularly fast at high temperature. This reaction probably prevents a gene from being expressed, a gene that makes the red pigment.

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.

Is Yersinia pestis aerobic or anaerobic?

Yersinia pestis, the causative agent of plague, is a pleomorphic, gram negative coccobacillus in the family Enterobacteriaceae. It is an aerobic, facultatively anaerobic, and facultatively intracellular pathogen.

How do you differentiate Yersinia enterocolitica and Yersinia pestis?

Yersinia pseudotuberculosis is a parasite of rodents that is known to occasionally infect man. Yersinia pestis is the agent responsible for the plague. Yersinia enterocolitica causes gastroenteritis and is the most significant Yersinia species related to water transmission.

Does Yersinia enterocolitica ferment sucrose?

Y. enterocolitica ferments sucrose and Y.

Which bacteria are lactose fermenters?

Lactose usually is fermented rapidly by Escherichia, Klebsiella and some Enterobacter species and more slowly by Citrobacter and some Serratia species.

What is non lactose fermenting bacteria?

Organisms unable to ferment lactose will form normal-colored (i.e., un-dyed) colonies. The medium will remain yellow. Examples of non-lactose fermenting bacteria are Salmonella, Proteus species, Yersinia, Pseudomonas aeruginosa and Shigella.

Is Klebsiella a lactose fermentation?

Klebsiella pneumoniae is a gram-negative, lactose-fermenting, non-motile, aerobic rod-shaped bacterium. It has been a known human pathogen since it was first isolated in the late nineteenth century by Edwin Klebs.