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PubMed1981

Citrobacter meningitis and cerebral abscess in early infancy: cure by moxalactam.

A 7-week-old boy developed multiple cerebral abscesses as a complication of neonatal Citrobacter diversus meningitis. He was successfully treated medically with the experimental beta-lactam antibiotic, moxalactam. This is the first nonsurgical cure of brain abscess in early infancy. Fifty-eight percent of all previously reported cases of Citrobacter meningitis were complicated by brain abscess, mandating early, and serial computed tomography scanning in patients afflicted with the disorder. Moxalactam may become the chemotherapeutic agent of choice for the treatment of this serious neonatal infection.

Brain Abscess↗
PubMed1988

An epizootic infection of Citrobacter freundii in a guineapig colony: short communication.

An epizootic infection of Citrobacter freundii in a guineapig colony is reported. From 1300 guineapigs maintained in a colony, a total of 115 guineapigs died. Lesions found postmortem were suggestive of acute pneumonia and enteritis. Citrobacter freundii was consistently isolated from necropsy specimens of lung, liver, spleen and intestines of the animals. The source of infection was not ascertained.

Animals↗
PubMed1995

Purification and properties of crystalline 3-methylaspartase from two facultative anaerobes, Citrobacter sp. strain YG-0504 and Morganella morganii strain YG-0601.

3-Methylaspartase (3-methylaspartate ammonia-lyase, EC 4.3.1.2) from two facultative anaerobes from soil, Citrobacter sp. strain YG-0504 and Morganella morganii strain YG-0601, were purified and crystallized from their crude extracts. Both of the Citrobacter and Morganella enzymes appeared to be a dimer of subunits of M(r) 40,000 and 44,000, respectively. The enzymes had similar enzymological properties: optimum pH for the deamination reaction of (2S,3S)-3-methylaspartic acid, substrate specificity, inhibitor, divalent and monovalent cation requirement, and N-terminal amino acid sequence homology. However, some differences were detected in pH and temperature stability, optimum pH for the amination reaction of mesaconic acid, optimum temperature, specific activity, and stability during electrophoresis. Both enzymes had similar enzymological properties to the known 3-methylaspartase from an obligate anaerobic bacterium, Clostridium tetanomorphum H1, except kinetic constants and substrate specificities.

Amino Acid Sequence↗
PubMed1979

Neonatal meningitis due to Citrobacter koseri.

A five day old neonate was diagnosed as having bacterial meningitis and commenced on Ampicillin and Flucloxacillin. The organism was then found to be Citrobacter koseri and the antibiotics changed to Chloramphenicol systemically for two weeks. The child made an uneventful recovery. At four weeks of age her head circumference had increased unacceptably and a computerised axial tomography scan revealed a large frontal lobe abscess. Aspiration revealed a large pus filled cavity and Citrobacter koseri grown from the pus. The abscess was treated with repeated aspirations, often of 30-40 mls., and installation of Chloramphenicol combined with systemic Chloramphenicol for three weeks. At six months of age her head circumference was within normal limits and the was developmentally normal with no detectable neurological sequelae.

Chloramphenicol↗
PubMed2004

Fulminant citrobacter meningitis with multiple periventricular abscesses in a three-month-old infant.

Citrobacter, a Gram-negative enteric bacillus, is a rare cause of septicemia and meningitis, seldom reported beyond the neonatal period. It is characterized by a fulminant clinical course and a high incidence of complications, including brain abscesses. We studied a three-month-old infant with Citrobacter meningitis, who developed acute communicating hydrocephalus and multiple periventricular brain abscesses while on treatment. The patient died, despite intensive antibiotic treatment directed towards the causative organism, C. diversus.

Brain Abscess↗
PubMed2002

Impaired resistance and enhanced pathology during infection with a noninvasive, attaching-effacing enteric bacterial pathogen, Citrobacter rodentium, in mice lacking IL-12 or IFN-gamma.

Mice infected with Citrobacter rodentium represent an excellent model in which to examine immune defenses against an attaching-effacing enteric bacterial pathogen. Colonic tissue from mice infected with C. rodentium harbors increased transcripts for IL-12 and IFN-gamma and displays mucosal pathology compared with uninfected controls. In this study, the role of IL-12 and IFN-gamma in host defense and mucosal injury during C. rodentium infection was examined using gene knockout mice. IL-12p40(-/-) and IFN-gamma(-/-) mice were significantly more susceptible to mucosal and gut-derived systemic C. rodentium infection. In particular, a proportion of IL-12p40(-/-) mice died during infection. Analysis of the gut mucosa of IL-12p40(-/-) mice revealed an influx of CD4(+) T cells and a local IFN-gamma response. Infected IL-12p40(-/-) and IFN-gamma(-/-) mice also mounted anti-Citrobacter serum and gut-associated IgA responses and strongly expressed inducible NO synthase (iNOS) in mucosal tissue, despite diminished serum nitrite/nitrate levels. However, iNOS does not detectably contribute to host defense against C. rodentium, as iNOS(-/-) mice were not more susceptible to infection. However, C57BL/6 mice infected with C. rodentium up-regulated expression of the mouse beta-defensin (mBD)-1 and mBD-3 in colonic tissue. In contrast, expression of mBD-3, but not mBD-1, was significantly attenuated during infection of IL-12- and IFN-gamma-deficient mice, suggesting mBD-3 may contribute to host defense. These studies are among the first to examine mechanisms of host resistance to an attaching-effacing pathogen and show an important role for IL-12 and IFN-gamma in limiting bacterial infection of the colonic epithelium.

Administration, Oral↗
PubMed2004

Critical role of T cell-dependent serum antibody, but not the gut-associated lymphoid tissue, for surviving acute mucosal infection with Citrobacter rodentium, an attaching and effacing pathogen.

Citrobacter rodentium uses virulence factors similar to the enteropathogenic Escherichia coli to produce attaching and effacing lesions in the distal colon of mice. We used this infection model to determine components of adaptive immunity needed to survive infection. During acute infection, wild-type mice develop breaks across infected epithelial surfaces but resolve infection. Surprisingly, mice markedly deficient in mucosal lymphocyte populations from beta(7) integrin deficiency resolve infection, as do CD8alpha-/- or TCR-delta-/- mice. In contrast, CD4-/- or TCR-beta-/- mice develop polymicrobial sepsis and end-organ damage, and succumb during acute infection, despite epithelial damage similar to wild-type mice. B cell-deficient (MuMT-/-) or B and T cell-deficient (recombinase-activating gene 2-/-) mice develop severe pathology in colon and internal organs, and deteriorate rapidly during acute infection. Surviving mice develop robust Citrobacter-specific serum IgM responses during acute infection, whereas mice that succumb do not. However, CD4-/- mice receiving serum Igs from infected wild-type mice survive and clear the infection. Our data show that survival of apparently self-limited and luminal mucosal infections requires a systemic T cell-dependent Ab response against bacteria that enter through damaged mucosa. These findings have implications for understanding host defense against mucosal infections, including the pathogenesis of these diseases in immunocompromised populations.

Abscess↗
PubMed1976

[Bacteria of the citrobacter genus as one of the possible indeices of dysbacteriosis in intestinal diseases].

A study of the incidence of detection of bacteria of the Citrobacter genus in chronic intestinal diseases with the clinical and bacteriological manifestations of dysbacteriosis indicated that the mentioned conditioned pathogenic bacteria were revealed with the same frequency as bacteria of the Proteus genus which served as the commonly accepted index of intestinal dysbacteriosis. Comparative analysis of the intestinal microbial flora of the patients led to a supposition that bacteria of the Citrobacter genus could be found not only in the associations with other microbes, but also as a definite individual group of bacteria during the infectious disease and antibiotic therapy in case of disturbance of normal intestinal biocenosis; this could occur even in the absence in these patients of the known bacteriological indices of dysbacteriosis, thus becoming one of its manifestations.

Anti-Bacterial Agents↗
PubMed1976

[Changes in the surface structures of bacteria as a cause of weak immunogenicity of vaccines from several strains of Citrobacter].

The authors present the results of studying the weakly immunogenic Citrobacter strains; some O-antigens of Citrobacter (11, 14, 19, 21a, 21b, 26) caused in immunization of rabbits a weak immune response (antibody titre--1:400-1:800). An electron microscopic study of the vaccines (obtained from these strains) and their fragments showed that a partial desquamation and denaturing of the antigenic material occurred in the process of preparation of heated vaccines. Formalin-treated vaccine subjected to preliminary deflaggelation for 2 min at 3000 cps was used for obtaining the O-sera against the mentioned antigens.

Agglutination Tests↗
PubMed1999

Biodegradation of tannic acid by Citrobacter freundii isolated from a tannery effluent.

A bacterial strain capable of utilizing tannic acid as sole carbon source was isolated from the effluent of a tannery and was identified as Citrobacter freundii. This organism could grow at concentrations as high as 5% (w/v) of tannic acid and produced extracellular tannase to hydrolyze the same. When grown in minimal medium containing 1% tannic acid (w/v) at 30 degrees C, this strain produced 1.87 U/ml of tannase at 6 h. At that time, tannic acid degradation products, namely glucose and gallic acid, were detectable in the culture filtrate; the other intermediate metabolites formed were pyrogallol (extracellular) and pyruvate (intracellular). 2-hydroxymuconic acid is presumed to form as a result of ortho-cleavage of pyrogallol. The proposed biochemical pathway for the degradation of tannic acid by Citrobacter freundii is: Tannic acid-->[Glucose + Gallic acid]-->Pyrogallol -->2-hydroxymuconic acid -->[?]-->Pyruvate.

Biodegradation, Environmental↗
PubMed1999

[Citrobacter freundii endocarditis].

Infection by Citrobacter appears in man only in certain circumstances, since it usually acts as contaminant or colonizer. Bacteraemia by this bacillus can affect immunodeficient people, elderly people or those patients who have undergone invasive hospital processes. Although incidence of bacteraemia is low (0.3-0.9%), the death rate is very high, about 48%. This bacillus is seldom the cause of endocarditis. That is why we describe a case of endocarditis by Citrobacter freundii, in an aged person with previous valvulopathy.

Aged↗
PubMed1975

First isolations of Levinea-Citrobacter cultures in Czechoslovakia.

Twenty-two strains corresponding by their biochemical properties to the genus Levinea - Citrobacter were isolated. Six of the strains were referred to the species Citrobacter diversus and 12 to C. freundii, whose properties are identical with those of L. malonatica and L. amalonatica, respectively. Four strains differed from Levinea organisms by some reactions, but were fully compatible with C. freundii (in the scheme of EWING and DAVIS); two of them utilized malonate. The taxonomic position of strains displaying the following biochemical properties: dextrose positive, indole positive, H2S negative, urease on Christensen's citrate medium positive, lysine-decarboxylase negative-is discussed. In routine practice, these strains may be more accurately identified by adding of four tests: adonitol with gas production, KCN, raffinose and malonate.

Carboxy-Lyases↗
PubMed2002

Citrobacter koseri in scalp folliculitis.

Gram-negative folliculitis, an uncommon condition, is most often seen in older patients who have acne and who either have received prolonged courses of antibiotic therapy or have used antibacterial cleansers that selectively inhibit gram-positive organisms. Citrobacter infections are uncommon, and dermatologists seldom encounter them. In the past, these infections occurred in hospitals, particularly in neonatal intensive care units. Bacteremias also occur in elderly or immunocompromised patients. In this article, we present a case of Citrobacter koseri scalp folliculitis in an otherwise healthy patient.

Anti-Infective Agents↗
PubMed2002

Structures and serology of the O-specific polysaccharides of bacteria of the genus Citrobacter.

The review presents the structures of the O-specific polysaccharides (O-antigens) of the lipopolysaccharides isolated from over 25 Citrobacter strains, which represent different species and serogroups. The correlation between O-antigen structure and immunospecificity as well as numerous cross-reactions between Citrobacter and other enterobacterial species are discussed.

Citrobacter↗
PubMed2003

[Recovery of platinum with immobilized Citrobacter freudii XP05 biomass].

The objective of this work was to develop a valuable adsorbent for recovery of platinum by studying the properties of Pt4+ -adsorption with immobilized Citrobacter freudii XP05 biomass. Five methods for immobilization of Citrobacter freudii XP05 biomass were compared. The method with gelatin-alginate sodium as entrapment matrix was considered to be the optimal. Spherical and uniform beads were produced and the SEM micrograph indicated that the cell of strain XP08 were uniformly dispersed within the matrix. The adsorption of Pt4+ by immobilized XP05 biomass was affected with adsorptive time, pH value of the solution, immobilized biomass concentration, Pt4+ initial concentration The adsorption was a rapid process. The optimal pH value for Pt4+ adsorption was 1.5, and its adsorptive capacity increased linearly with increasing Pt4+ initial concentrations in the range of 50 - 250 mg/L. The experimental data could be fitted to Langmuir and Freundlich models of adsorption isotherm. The adsorptive capacity reached 35.2 mg/g under the conditions of 250 Pt4+ mg/L, 2.0 g/L immobilized biomass, pH 1.5 and 30 degrees C for 60 min. 98.7% of Pt4+ adsorbed on immobilized biomass could be desorbed with 0.5 mol HC1/L. The characteristics of dynamic adsorption and desorption of immobilized XP05 biomass in packed-bed reactor were investigated. The saturation uptake was 24.66 mg Pt4+ /g under the conditions of flow rate 1.2 mL/min, pH 1.5, 50 mg Pt4+/L and 1.85 g biomass(dry weight) . Adsorptive efficiency of Pt4 + by the immobilized XP05 biomass was above 78% for 4 cycles of adsorption and desorption. The recovery of platinum from waste platinum catalyst was studied. The adsorptive capacity was 20.94 mg Pt4+/g immobilized biomass under the conditions of 4.0 g/L immobilized XP05 biomass, 117.76 mg Pt4+/L and pH 1.5 for 60 min. The immobilized XP05 biomass is potentially applicable to the recovery of platinum from waste and wastewater containing platinum.

Biomass↗
PubMed2006

[Purification and properties of Citrobacter freundii phytase].

Phytase (myo-inositol-1,2,3,4,5,6-hexakisphosphate phosphohydrolase, EC 3.1.3.26) catalyses the stepwise hydrolysis of phytic acid (myo-inositol hexakisphosphate). Phytases are of great commercial importance due to their usage as supplement of food and animal feed, which can cater to nutrition demands and alleviate environmental problems, has been approved by many countries. Although acid phytases have been extensively studied, information regarding the phytases from Citrobacter is limited. In the work presented, a phytase was separated from Citrobacter freundii. After steps of electrophoretic homogeneity by successive ammonium sulfate between 60% and 80% saturation precipitation, DEAE-Sepharose ion-exchange chromatography and gel filtration through Superdex HR 10/30, final gel elution resulted in a 41.3-fold purification and yield of 9.3%. Gel elution is an effective method to purify the protein which contaminated with a few other proteins. The purified preparations were used in subsequent characterization studies. Based on SDS-PAGE analysis, the molecular weight of the purified phytase was calculated to be approximately 45.0kDa in monomeric form. The pure enzyme has an optimum pH of 4.0 to approximately 4.5. It was found stable between pH5.0 to approximately 7.0, about 90% of the enzyme activity was retained at 37 degrees C for 60min. The phytase has an optimum temperature of 40 degrees C which was lower than that of other phytases from Aspergillus or E. coli (average 50 to approximately 60 degrees C) and was close to the temperature of gastrointestinal tract in animals (37 to approximately 40 degrees C). Thus the enzyme is a promising candidate for animal feed applications. Activity of the purified phytase was influenced by changing the reaction temperature. Data showed that the enzyme retained its activity over a long period when stored at 4 degrees C, whereas thermal inactivation studies indicated that the enzyme lost 100% activity after treatment at 60 degrees C for 4min. The Km values of the phytase for dodecasodium phytate at 37 degrees C was 0.85nmol/L with a Vmax 0.53IU/(mg x min). Phytase activity was strongly inhibited by SDS, Zn2+ and moderately inhibited by Cu2+, Cr3+, Fe2+ and Fe3+. Activity was not significantly affected by EDTA, K+, Mg2+ and Ca2+. The phytase has excellent resistance to trypsin, but not pepsin. The N-terminal amino acids sequence of the phytase protein was determined as QCAPEGYQLQQVLMM which exhibited about 80% homology to Glucose-1-phosphatases from E. coli, Shigella flexneri and Salmonella, whereas it did not show apparent sequence similarity with any other phytase listed in the databases. Initial characterization of the purified enzyme suggested that it is a potential candidate for use as an animal feed supplement.

6-Phytase↗
PubMed1990

[Standardization of the determination of the fimbriae (adhesins) of Citrobacter].

Trials of guinea pig formalin-treated red cells have shown their stability for at least 3 years and fitness, equal to that of native cells, for the detection of Citrobacter mannose-sensitive and resistant adhesins in hemagglutination and adhesion tests (red cell binding of bacteria). Comparison of the results of bacterial binding and bacterial agglutination of red cells in tests on slides and in wells has shown that the use of fixed red cells accelerates agglutination and makes it more sensitive, probably at the expense of altering the red cell physicochemical characteristics by fixation. Use of formalin-treated red cells essentially simplifies Citrobacter adhesion determination and makes it possible in any conditions.

Bacteriological Techniques↗
PubMed1986

[Erythrocyte diagnostic agents for detecting bacterial antigens of the genus Citrobacter].

Citrobacter antigenic and antibody erythrocyte diagnosticums, serogroups 1, 2, 3, 4, 5, 6, 7, 8, 11, 12, 13, and 22, have been developed. Tests with the use of these diagnosticums have proved to be highly sensitive and mainly group-specific. The antigen in the cellular form is best detected by means of the passive hemagglutination test and in the molecular form, by means of the neutralization test. The antibody-binding and agglutinating activities of strictly group-specific and cross-reacting O-antigenic determinants differ in their sensitivity to heating and to treatment with phenol. In the study of fecal samples taken from patients the above method for the detection of Citrobacter antigens has been shown to have high resolution.

Animals↗