Is Citrobacter freundii indole positive?
The genus Citrobacter consists of Gram-negative peritrichous rods. The genus is subdivided into two species: (1) Citrobacter freundii (includes mostly H2S-positive, indole-negative, and adonitol-negative cultures) and (2) Citrobacter diversus (composed of H2S-negative, indole-positive, and adonitol-positive cultures).
What are the characteristics of Citrobacter freundii?
Citrobacter freundii are long rod-shaped bacteria typically 1-5 μm in length . Most C. freundii cells are surrounded by many flagella used to move about, but a few are non-motile. Its habitat includes the environment (soil, water, sewage), food, and the intestinal tracts of animals and humans .
Is C. freundii citrate positive?
rodentium (formerly Citrobacter freundii strain 4280), is a nonmotile, gram-negative rod that ferments lactose but does not utilize citrate or does so marginally (Barthold, 1980; Schauer et al., 1995).
Is Citrobacter freundii oxidase positive or negative?
Biochemical Test and Identification of Citrobacter freundii
|Basic Characteristics||Properties (Citrobacter freundii)|
What is the morphology of Citrobacter freundii?
|Morphology:||Straight rods, occurring singly and in pairs.|
|Size:||Approximately 1 micrometer in diameter by 2.0-6.0 micrometers in length.|
|Motility:||Usually motile by peritrichous flagella.|
Is Citrobacter freundii Gram positive or negative?
Members of the genus Citrobacter are gram-negative, non-sporing rods belonging to family Enterobacteriaceae and, as the name suggests, usually utilize citrate as a sole carbon source.
Does Citrobacter freundii grow on MacConkey Agar?
C. freundii form small, circular, convex dark pink colonies on MacConkey agar. Rough or mucoid forms have also been reported. Citrobacter species grow optimally at a temperature of 37 °C.
Is Citrobacter freundii motile?
Citrobacter freundii is a motile gram-negative bacterium living in soil and aqueous environments; it is often isolated in clinical specimens as an opportunistic pathogen.
Is Citrobacter freundii a glucose fermenter?
They ferment glucose and other carbohydrates with the production of acid and gas. They are oxidase negative, catalase and methyl red positive, Voges-Proskauer negative, and do not decarboxylate lysine. Taxonomically, the genus Citrobacter is most closely related to Salmonella and Escherichia.
What is Citrobacter freundii complex?
Citrobacter freundii complex has been implicated as a cause of gastrointestinal infection and inflammation, acute dysentery, and dyspepsia. Acute symptoms can include profuse, watery diarrhea without abdominal pain, fecal blood, or white blood cells. Citrobacter spp.
What is the Gram reaction of Citrobacter freundii?
Citrobacter freundii are facultative anaerobic Gram-negative coliform bacteria in the Enterobacteriaceae family.
Does Citrobacter grow on Mac?
Citrobacter spp. are late lactose fermenters and they grow on MacConkey Agar.
Does Citrobacter Freundii grow on MacConkey Agar?
What is the morphology of Citrobacter Freundii?
Does Citrobacter freundii grow on MacConkey agar?
Biochemical Test and Identification of Citrobacter freundii Basic Characteristics Properties ( Citrobacter freundii) Gelatin Hydrolysis Negative (-ve) Gram Staining Negative (-ve) Growth in KCN Positive (+ve) H2S Positive (+ve)
How do you make an indole test?
Procedure of Indole Test. Take a sterilized test tubes containing 4 ml of tryptophan broth. Inoculate the tube aseptically by taking the growth from 18 to 24 hrs culture. Incubate the tube at 37°C for 24-28 hours. Add 0.5 ml of Kovac’s reagent to the broth culture.
What is indole positive and indole negative?
Formation of red or pink colored ring at the top is taken as Positive. No color change after addition of reagent is taken as Negative. Most strains of E.coli, P. vulgaris, M. morganii and Providenica are indole positive. Along with differentiation of enterics, Indole test can also be used for species differentiation.
What is the difference between spot test and tube test for indole?
The tube test is a more sensitive method of detecting indole than the spot test. When performing a spot test, Kovacs Indole Reagent may be used as a substitute for the spot test reagent.