What bacteria are lactose fermenting gram negative rods?
E. coli are facultative anaerobic, Gram-negative bacilli that will ferment lactose to produce hydrogen sulfide.
Which organisms are lactose fermenters?
Lactose usually is fermented rapidly by Escherichia, Klebsiella and some Enterobacter species and more slowly by Citrobacter and some Serratia species. Proteus, unlike the coliforms, deaminates phenylalanine to phenylpyruvic acid, and it does not ferment lactose. Typically, Proteus is rapidly urease positive.
Is E. coli a late lactose fermenter?
E. coli isolates that look like Strain D are usually so called “late lactose fermenters” (or delayed lactose fermenters). The delayed fermenters have the potential to ferment lactose (they produce the intracellular enzyme necessary to metabolize lactose) but they lack the β-galactosidase-permease enzyme.
Is Shigella Sonnei a lactose fermenter?
Shigella sonnei is a rod-shape bacterium and is lactose-fermenting bacterium causing dysentery (4).
Does Proteus mirabilis ferment lactose?
Proteus mirabilis, part of the Enterobacteriaceae family of bacilli, is a gram-negative, facultative anaerobe with an ability to ferment maltose and inability to ferment lactose.
Is Klebsiella a lactose fermenter?
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. The microbiology, pathogenesis, and epidemiology of infections due to K. pneumoniae will be reviewed here.
Is Proteus mirabilis lactose fermentation?
Is Klebsiella pneumoniae indole negative?
The two clinically relevant species, Klebsiella pneumoniae and Klebsiella oxytoca, are differentiated by the ability to produce indole from tryptophan, K. oxytoca being indole positive.
Is Salmonella lactose fermenter?
To differentiate Salmonella from other Enterobacteriaceae, bacteriologists use lactose fermentation as a key biochemical test. As early as 1887, it was known that Escherichia coli was a lactose fermenter and that Salmonella was not a lactose fermenter.
Is Shigella sonnei indole positive or negative?
negative
In the case of Shigella, the indole reaction is consistently negative only in specific serotypes within each traditional species of Shigella, including 7 of the 10 S. dysenteriae serotypes, 9 of the 15 S.
Does Proteus vulgaris ferment lactose?
According to laboratory fermentation tests, P. vulgaris ferments glucose and amygdalin, but does not ferment mannitol or lactose. P. vulgaris also tests positive for the methyl red (mixed acid fermentation) test and is also an extremely motile organism.
Is Proteus mirabilis indole negative?
Proteus mirabilis (indole negative) is the most frequent Proteus species associated with urinary tract infections, but indole-positive Proteus species like Pr. vulgaris, which are more often resistant to ampicillin, may also cause urinary tract infections. These species are often associated with an alkaline urine.
Is Salmonella lactose positive or negative?
Since 1971 a lactose-positive (lac+) Salmonella typhimurium variety Copenhagen has been endemic in the city of Sao Paulo. The strain is a strong lactose fermenter and resembles Escherichia coli on primary plating media and in triple sugar iron agar.
Is Pseudomonas aeruginosa indole-positive or negative?
Negative (-ve)
Biochemical Test and Identification of Pseudomonas aeruginosa
| Characteristics | Pseudomonas aeruginosa |
|---|---|
| Indole | Negative (-ve) |
| Citrate | Positive (+ve) |
| Urease | Negative (-ve) |
| Nitrate Reduction | Positive (+ve) |
Is Proteus mirabilis indole positive?
Proteus mirabilis (indole negative) is the most frequent Proteus species associated with urinary tract infections, but indole-positive Proteus species like Pr. vulgaris, which are more often resistant to ampicillin, may also cause urinary tract infections.
Is Pseudomonas aeruginosa indole positive or negative?
Which organisms are indole positive and citrate negative?
a. Indole positive; citrate negative Organism: Escherichia coli b. Indole negative: Go to Section D.2 2. H2S production a. H2S produced; citrate positive Organism: Citrobacter freundi b. H2S not produced: Go to Section D.3 3. Urease Test a. Urease postive Organism: Klebsiella pneumoniae b. Urease negative Organism: Enterobacter aerogenes 1.
What is indole positive and indole negative?
Indole positive organisms Most strains of E.coli, P. vulgaris, M. morganii and Providenica are indole positive. Point to remember: Indole test can also aid in species differentiation. Klebsiella species: Klebsiella oxytoca is indole positive whereas Klebsiella pneumoniae is indole negative.
Is Propionibacterium acnes indole positive or negative?
Propionibacterium acnes is indole positive. Spot indole tests along with gram stain results and colony characteristics can assist in the rapid identification of isolates. For example; a flat, dry lactose fermenting (pink) colony on MacConkey agar that is also spot indole positive and oxidase negative can be reported presumptively as E.coli.
Is Citrobacter koseri indole positive or indole negative?
Citrobacter species: Citrobacter Koseri is indole positive where as Citrobacter freundii is indole negative. Proteus species: Proteus Vulgaris is indole positive whereas Proteus mirabilis is indole negative. I used to remember the above-mentioned information with the help of MNEMONIC, which can be useful for you.