what is the morphology of citrobacter freundii

What causes Citrobacter UTI?

What are the 6 signs of sepsis?

• feeling dizzy or faint.
• a change in mental state – such as confusion or disorientation.
• diarrhoea.
• nausea and vomiting.
• slurred speech.
• severe muscle pain.
• severe breathlessness.
• less urine production than normal – for example, not urinating for a day.

Does Citrobacter freundi ferment lactose?

freundii can use citrate as a sole carbon source. Citrobacter species are differentiated by their ability to convert tryptophan to indole (C. koseri is the only citrobacter to be commonly indole-positive), ferment lactose (C. koseri is a lactose fermentor), and use malonate.

Does Citrobacter freundii have a capsule?

Citrobacter: environmental sources and in feces of man and animals. Can infect any body site opportunistically, but most isolates from the urinary tract; neonatal meningitis and brain abscesses by Citrobacter diversus. Citrobacter freundii can be enterotoxigenic. Antigenic structure: O, H, K antigens

Is Citrobacter diversus motile?

Introduction Citrobacter koseri, formerly known as Citrobacter diversus, is a facultative anaerobe and motile, gram-negative bacillus of the family Enterobacteriaceae. Citrobacterspp. have been implicated in a wide array of disease processes, including urinary tract infections, pneumonia, and bacteremia.

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What is the shape and arrangement of Citrobacter freundii?

Citrobacter freundii are facultative anaerobic Gram-negative coliform bacteria in the Enterobacteriaceae family. The bacteria are long rod-shaped with a typical length of 1-5 μm. Most C.

What are the characteristics of Citrobacter freundii?

Citrobacter freundii are long rod-shaped bacteria typically 1-5 μm in length [1]. 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 [1].

Is Citrobacter freundii Gram positive or Gram-negative?

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).

What is Citrobacter freundii complex?

Citrobacter freundii is a species of facultative anaerobic Gram-negative bacteria of the family Enterobacteriaceae which currently consists of 13 recognized species. These bacteria have a rod shape with a typical length of 1–5 μm. Most 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.

What color is Citrobacter freundii?

grey coloredCitrobacter freundii on Nutrient Agar Smooth, convex, translucent, or opaque grey colored with a shiny surface and entire margin; mucoid or rough colonies occasionally.

What is the genus of Citrobacter freundii?

CitrobacterCitrobacter freundii / GenusCitrobacter is a genus of Gram-negative coliform bacteria in the family Enterobacteriaceae. The species C. amalonaticus, C. koseri, and C. freundii can use citrate as a sole carbon source. Citrobacter species are differentiated by their ability to convert tryptophan to indole, ferment lactose, and use malonate. Wikipedia

Is Citrobacter aerobic or anaerobic?

MICROBIOLOGY. Citrobacter species are straight, facultative anaerobic, Gram-negative bacilli and are typically motile by means of peritrichous flagellae.

Is Citrobacter freundii coagulase positive or negative?

Biochemical Test and Identification of Citrobacter freundiiBasic CharacteristicsProperties (Citrobacter freundii)Gas from glucosePositive (+ve)Gelatin HydrolysisNegative (-ve)Gram StainingNegative (-ve)Growth in KCNPositive (+ve)59 more rows•Aug 15, 2019

Is Citrobacter freundii indole positive?

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).

Is Citrobacter freundii a coliform?

The MF technique indicated that Citrobacter freundii was the most common coliform species in water samples.

What is Citrobacter freundii sensitive to?

An examination of 99 field and reference strains of Citrobacter freundii showed 79% of them to be resistant to cephaloridine and sensitive to carbenicillin, while 96% of 45 field and reference strains of Citrobacter koseri examined were sensitive to cephaloridine and resistant to carbenicillin.

Where is Citrobacter freundii found?

Citrobacter freundii is isolated from human and animal feces, as well as from extraintestinal specimens. It is also commonly found in soil water and food. Citrobacter diversus is a rare but important agent of neonatal meningitis and infections in compromised hosts.

What is the genus of Citrobacter?

Citrobacter, which was first described as Bacterium freundii in 1928, was reclassified as Citrobacter in 1932 Doran (1999), Sedlak (1973). The genus Citrobacter belongs to the family Enterobacteriaceae and is subdivided into the tribe Citrobacteriaceae.

What are the different types of Citrobacter?

Of the dozen species, Citrobacter freundii, Citrobacter koseri (formerly Citrobacter diversus ), and Citrobacter amalonaticus are linked to human disease. They are differentiated by their ability to convert tryptophan to indole, ferment lactose, and use malonate. 338 C. freundii produces hydrogen sulfide and hence can be confused with Salmonella, with which it was classified at one time. The urinary tract is the most frequent site from which Citrobacter is cultured, often in association with an indwelling catheter. These bacteria may also be cultured from the respiratory tract, a finding that more often represents colonization than symptomatic infection. Citrobacter strains are also involved in intra-abdominal infections and can cause soft tissue infections and osteomyelitis. 339,340 Invasive procedures may play a role in Citrobacter bacteremia. 341 C. koseri has caused frequent nosocomial outbreaks of neonatal meningitis. In several instances, the outbreaks have been accompanied by high rates of intestinal colonization by the organism in infants and by carriage of the bacteria on the hands of health care workers. 342 C. freundii strains, like strains of Enterobacter and Serratia, have inducible ampC genes encoding resistance to ampicillin and first-generation cephalosporins that can be produced constitutively at high levels after mutations. In addition, like members of these other genera, isolates of Citrobacter may be resistant to multiple other antibiotics as a result of plasmid-encoded resistance genes.

What is the level of bacteriocin in E. coli?

coli, Salmonella enterica, Hafnia alvei, Citrobacter freundii, Klebsiella oxytoca, Klebsiella pneumoniae, and Enterobacter cloacae reveal levels of bacteriocin production ranging from 3 to 26% of environmental isolates. Colicins, bacteriocins produced by E. coli, were found in 30–50% of the strains isolated from human hosts and are often referred to as a virulence factor. Much higher production levels have been found in some enterics, such as Pseudomonas aeruginosa, in which 90% or more of both environmental and clinical isolates produce bacteriocins.

How many species are in the genus Citrobacter?

The genus Citrobacter has undergone significant taxonomic revision through the use of newer techniques based on DNA relatedness. The genus contains 11 named species: Citrobacter freundii, C. koseri (formerly C. diversus), C. amalonaticus, C. youngae, C. farmeri, C. braakii, C. werkmanii, C. sedlakii, C. gillenii, C. murliniae, and C. rodentium.1–5 All species except C. rodentium (pathogenic for mice) have been recovered from human clinical specimens. However, C. freundii and C. koseri and C. braakii are the most important human pathogens. C. freundii, C. koseri, and C. amalonaticus appear to be distinct organisms, but only C. koseri appears to be genetically homogeneous. Several other named species form a closely related group and are difficult to differentiate biochemically; they are sometimes referred to as C. freundii complex organisms.

What is the difference between Salmonella and Citrobacter?

One of the biochemical properties that differentiate Salmonella from Citrobacter is the ability to decarboxylate lysine: 90–100% of Salmonella strains and only 0–10% of Citrobacter strains exhibit this de carboxylation.

Where is Citrobacter cultured?

The urinary tract is the most frequent site from which Citrobacter is cultured, often in association with an indwelling catheter. These bacteria may also be cultured from the respiratory tract, a finding that more often represents colonization than symptomatic infection.

Where is Citrobacter freundii found?

Citrobacter freundii are commonly found in the environment, mainly in soil, water, and sewages. They are an indicator of potential contamination of water. They are also found on different organs of diseased animals, including mammals, birds, reptiles, and amphibians [1]. They are not known to interact with other organims.

What is the habitat of Citrobacter freundii?

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 [1].

How long is a C. freundii cell?

The cell structure of C. freundi is long and rod-shaped usually 1-5 μm in length. The outside of the cell contains many flagella used for motality [1]. Since C. freundii is gram-negative bacteria, it contains two membranes (inner and outer).The periplasmic space lies in between the two membranes.

How does C. freundii grow?

For metabolism, C. freundii has an amazing ability to grow on glycerol as the sole carbon and energy source. In this process, glycerol is fermented by a dismutation process. This process requires two pathways [8]. In the first pathway, glycerol is dehydrogenated by a NAD1-linked glycerol dehydrogenase to dihydroxyacetone. The dihydroxyacetone is then phosphorylated and funneled to glycolysis by dihydroxyacetone kinase [8]. In the second pathway, glycerol is dehydrated by the coenzyme B12-dependent glycerol dehydratase to form 3-hydroxypropionaldehyde [8]. This product is reduced to the major fermentation product 1,3-propanediol by the NADH-linked 1,3-propanediol dehydrogenase, which regenerates NAD1. The dha regulon encodes the four essential enzymes of these two pathways. Amazingly, the expression of the dha regulon is only induced when glycerol is present [8].

Why are C. freundii sequenced?

freundii genome are being sequenced is in order to find antibiotics that can fight these opportunistic infections. Surprisingly, this infectious microbe in humans plays a positive role in the environment.

When was the Citrobacter genus discovered?

The Citrobacter genus was discovered in 1932 by Werkman and Gillen. Cultures of C. freundii were isolated and identified in the same year from soil extracts [1].

What is the cause of trout cyprinids?

Certain diseases studied in trout and cyprinids are also caused by C. freundii. C. freundii causes abnormal inflammatory changes in the intestine of trout and inflammatory and necrotic changes in the internal organs of cyprinids. The illness was discovered by means of artificial infection with a pure culture of C. freundii. This discovery established C. freundii as a cause of fish disease [11].

What page is antibiotic resistance in Citrobacterspp. isolated from urinary tract infection?

See the article "Antibiotic resistance in Citrobacterspp. isolated from urinary tract infection" on page 312.

What is the third most common urinary pathogen?

The authors have conducted a retrospective study and have reported Citrobacterspp . as the third most common urinary pathogen accounting for 9.4% of the total isolates. The isolation of this organism was associated with catheterization, genitourinary instrumentation, or obstructive uropathy. Also, the age group most affected was that of elderly hospitalized patients, especially males. Their finding emphasizes the role of this organism as a common health care associated pathogen. Recently, a study conducted in Nepal also reported Citrobacterspp. as the second most common urinary pathogen in their study.[4]

Is Citrobacterspp a nosocomial?

Although Citrobacterspp. are less commonly isolated, they are emerging as a common nosocomial multidrug-resistant pathogen, especially in developing countries. UTI caused by Citrobacterspp. have been seen in 12% patients in 1961, and since then, its prevalence has been increasing.[5] Invasive procedures like catheterization or genitourinary instrumentation seem to assist the organism in colonization and infection of urinary tract. Another matter of concern is the emergence of multidrug-resistant Citrobacterspp., resulting in reduced therapeutic options which further complicate the situation. The author also reported that most of the isolates were resistant to penicillins, cephalosporins, aminoglycosides, and fluoroquinolones, which are the commonly prescribed drugs in UTI. Resistance to many groups of antibiotics has been observed and many mechanisms of drug resistance have been demonstrated in Citrobacterspp. In a study concluded by Shobha et al., Citrobacterspp. was the third most common urinary pathogen and 30% of the isolates were extended spectrum beta lactamase (ESBL) producers.[6] Meher Rizvi et al. reported that 62.2% of Citrobacterisolates were producing ESBL.[7] High level carbapenem resistance was also reported in C. freundiidue to combination of Klebsiella pneumoniaecarbapenemase-2 (KPC-2) production and decreased porin expression.[8] Carbapenems are important antibiotics for the treatment of health care associated infections and have a special role in treating infection with ESBL-producing organisms. The emergence and spread of resistance to carbapenems will end all the treatment options available for treating multidrug-resistant pathogens.

Classification

Description and Significance

• Photo: Pete Wardell/ CDC The Citrobacter species, including Citrobacter freundii, are aerobic gram-negative bacilli. 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, se...

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Genome Structure

Cell Structure and Metabolism

Ecology

Pathology

Application to Biotechnology

Current Research

Antibiotic Resistance

References