Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “PROTEUS”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,009 records · Page 56Linked to original sources
PubMed1997

Which indwelling urethral catheters resist encrustation by Proteus mirabilis biofilms?

OBJECTIVE: To test the resistance of currently available types of indwelling urethral catheters to blockage by encrustation with mineralized Proteus mirabilis biofilms. MATERIALS AND METHODS: Encrustation was studied in a simple laboratory model of the catheterized bladder. Artificial urine was supplied to the bladder chamber at 0.5 mL/min. The bladder urine was inoculated with a clinical strain of P. mirabilis that had been isolated from an encrusted catheter. The models were operated until the catheters blocked and atomic absorption spectrometry was used to assess the amounts of calcium and magnesium deposited on the catheters. Scanning electron microscopy was also used to locate and assess the degree of encrustation. RESULTS: The mean times to blockage ranged from 21 h for the Bard hydrogel/silver-coated latex catheter to 56 h for the Eschmann Folatex S all-silicone catheter. The calcium and magnesium salts were mainly deposited on the 10 cm below the eye-holes of the catheters, complete blockage generally occurring in the 2 cm immediately below the eye-hole. CONCLUSION: None of the 18 types of catheter tested, including those coated with hydrogel or silver, were capable of resisting encrustation by P. mirabilis biofilm.

Biofilms↗
PubMed2001

Does drinking cranberry juice produce urine inhibitory to the development of crystalline, catheter-blocking Proteus mirabilis biofilms?

OBJECTIVE: To test the recommendation that to avoid the complications of long-term indwelling bladder catheterization (e.g. encrustation and blockage by crystalline Proteus mirabilis biofilms) patients should drink cranberry juice. MATERIALS AND METHODS: Urine was collected from groups of volunteers who had drunk up to 2 x 500 mL of cranberry juice or water within an 8-h period. Laboratory models of the catheterized bladder were supplied with urine from these groups and inoculated with P. mirabilis. After incubation for 24 or 48 h, the extent of catheter encrustation was determined by chemical analysis for calcium and magnesium. Encrustation was also visualized by scanning electron microscopy. RESULTS: The amounts of calcium and magnesium recovered from catheters incubated in urine pooled from individuals who had drunk 500 mL of cranberry juice was not significantly different from that on catheters incubated in pooled urine from control subjects who had drunk 500 mL of water. However, there was significantly less encrustation (P = 0.007) on catheters from models receiving urine from volunteers who had drunk 2 x 500 mL of water than on catheters incubated in models supplied with urine from volunteers who had drunk 2 x 500 mL of cranberry juice. The amounts of encrustation on these two groups of catheters were also significantly less than that on catheters incubated in models supplied with urine from volunteers who had not supplemented their normal fluid intake. (P < 0.001). Experiments in the models using artificial urine showed that increasing the low fluid intake (720 mL/24 h) characteristic of many patients undergoing long-term catheterization by factors of three and six, significantly (P < 0.01) reduced the amounts of calcium and magnesium that formed on catheters. At a simulated fluid intake of 720 mL/24 h, catheters blocked with encrustation after a mean of 42.5 h, while those supplied with urine produced from an intake of 4320 mL/24 h, drained freely for > 10 days. CONCLUSION: In this in vitro study, drinking cranberry juice did not produce urine that was inhibitory to the development of crystalline catheter-blocking P. mirabilis biofilms. The important factor in preventing catheter encrustation is a high fluid intake.

Beverages↗
PubMed1994

The radiological features of hemimegalencephaly including three cases associated with proteus syndrome.

We report the radiological appearances of 5 children with hemimegalencephaly. There are few reports of this rare condition in the radiological literature. Two of the children have hemimegalencephaly as an isolated finding while the other three have Proteus syndrome. Four children have seizures which commenced within the first 6 months of life and two of these subsequently required hemispherectomy. In addition to the typical radiological features of hemimegalencephaly there was a high incidence of other brain anomalies. These include hypoplasia of the corpus callosum and crus cerebri, grey and white matter calcification and cortical migration/organisational disorders.

Brain↗
PubMed1977

Selective amplification of genes on the R plasmid, NR1, in Proteus mirabilis: an example of the induction of selective gene amplification.

The drug-resistance plasmid, NR1, is a 37-micron circular DNA molecule that contains two components: the resistance transfer factor (29 micron) carrying the transfer genes and the genes for tetracycline resistance, and the r-determinant (8 micron) carrying the genes for resistance to several other antibiotics including chloramphenicol (Cm). In Proteus mirabilis, these two components are capable of independent replication, or they may replicate as a composite molecule. When cells of P. mirabilis containing NR1 are cultured in medium containing Cm at 250 microgram/ml a growth lag of 20-35 hr ensues. During this lag, Cm induces the selective amplification of the r-determinant, including the gene for resistance to Cm. The amplification results from the excision of the r-determinant from the R plasmid, the independent replication of the r-determinant to give polymeric as well as monomeric r-determinants, and the eventual reintegration of multiple tandem copies of the r-determinant with the resistance transfer factor to form a new R plasmid with multiple copies of the r-determinant. This mechanism represents a new level of control of gene expression in bacterial systems--namely, the induction of selective gene amplification.

Cell Division↗
PubMed1998

Identification of a novel transcription regulator from Proteus mirabilis, PMTR, revealed a possible role of YJAI protein in balancing zinc in Escherichia coli.

Zinc is an essential trace element required for structural integrity and functional activity of numerous proteins, yet mechanisms by which cells regulate zinc concentration are poorly understood. Here, we identified a gene from Proteus mirabilis that encodes a 135-amino acid residue protein, PMTR (P. mirabilis transcription regulator), a new member of the MerR family of transcription activators. Transformation of Escherichia coli with PMTR-carrying vectors specifically increases cell tolerance to zinc, suggesting the role of PMTR in zinc homeostasis. In response to zinc, PMTR-containing cells robustly accumulate a 12-kDa protein, the amount of which correlates with the cells' ability to grow at high zinc concentrations. The 12-kDa protein is not induced in the presence of Ni2+, Co2+, Cd2+, Mn2+, or Fe2+, indicating that the PMTR-dependent expression of the 12-kDa protein is specifically regulated by zinc. The 12-kDa protein was identified as the C-terminal fragment of E. coli protein YJAI, and was shown to contain two zinc-binding motifs. Metal-affinity chromatography and 65Zn blotting assay confirmed the ability of the 12-kDa protein to bind zinc specifically (zinc > cobalt >> cadmium). We propose that YJAI is an important component of the zinc-balancing mechanism in E. coli, the up-regulation of which with PMTR results in an increased tolerance to zinc.

Amino Acid Sequence↗
PubMed1999

The structure of the colony migration factor from pathogenic Proteus mirabilis. A capsular polysaccharide that facilitates swarming.

Swarming by Proteus mirabilis is characterized by cycles of rapid and coordinated population migration across surfaces following differentiation of vegetative cells into elongated hyperflagellated swarm cells. It has been shown that surface colony expansion by the swarm cell population is facilitated by a colony migration factor (Cmf), a capsular polysaccharide (CPS) that also contributes to the uropathogenicity of P. mirabilis (Gygi, D., Rahman, M. M., Lai, H.-C., Carlson, R., Guard-Petter, J., and Hughes, C. (1995) Mol. Microbiol. 17, 1167-1175). In this report, the Cmf-CPS was extracted with hot water, precipitated with ethanol, and further purified by gel permeation chromatography. Its structure was established by glycosyl composition and linkage analyses, and by one- and two-dimensional NMR spectroscopy. The Cmf-CPS is composed of the following tetrasaccharide repeating unit. [see text]

Carbohydrate Sequence↗
PubMed1998

Escherichia coli and Proteus mirabilis inhibit the perinuclear but not the circulating antineutrophil cytoplasmic antibody reaction.

BACKGROUND: Perinuclear antineutrophil cytoplasmic antibodies (P-ANCA) are found in 48%-83% of serum samples from patients with ulcerative colitis (UC). Their pathogenic role and initiating stimuli are unknown. In contrast to patients with vasculitides and ANCA reactivities, the antibodies in UC patients do not react with myeloperoxidase (MPO) or proteinase 3 (PR3). The aim of the present study was to investigate whether bacterial species of the intestinal tract and other sources could interfere with P-ANCA in sera from patients with UC. METHODS: Seventeen P-ANCA-positive and anti-MPO-negative serum samples from patients with UC were tested with Escherichia coli 014 and Staphylococcus aureus Wood 46. Six of these serum samples with different P-ANCA titres were selected to test further the influence of 15 different gram-negative or gram-positive bacterial strains. Six anti-MPO positive P-ANCA, 5 anti-PR3 positive C-ANCA, and 10 antinuclear antibody (ANA)-positive serum samples were used as controls. The antineutrophil cytoplasmic antibodies (ANCAs) were analysed by an indirect immunofluorescence method (IIF) on ethanol-fixed neutrophils, and the ANAs were tested by IIF on HEp-2 cells or rat liver tissues. The bacteria used in the experiments were either live or killed by formalin or glutaraldehyde fixation or heated at 80 degrees C for 30 min. The test was first performed as a bacterial absorption test with sedimented organisms and then at various temperatures with the supernatant from suspension of live bacteria. RESULTS: Both MPO-positive and MPO-negative P-ANCA reactivity was abolished by absorption of patient sera with live E. coli and Proteus mirabilis but not with bacteria representing members of 10 other species, suggesting that antibody reactivity was absorbed away. However, continued experiments indicated that the inhibition of P-ANCA was not due to classic antigen-antibody interactions but rather to decomposition of the antigenic substrate of the neutrophils by factors present in the supernatants of live E. coli and P. mirabilis. The activity of the supernatant was temperature-dependent, with strong activity at room temperature and 37 degrees C, no activity at 0 degrees C, and abolished by mild heat treatment (56 degrees or 60 degrees C). No activity was shown in the supernatants from bacteria treated with formaldehyde or glutaraldehyde. CONCLUSIONS: Soluble material from live E. coli and P. mirabilis has the capacity to decompose the antigenic substrate of neutrophils responsible for both MPO-positive and MPO-negative P-ANCA, most probably brought about through enzymatic activity. Anti PR3-positive C-ANCA were not affected, which suggests substrate specificity of the proposed enzymatic activity.

Adult↗
PubMed2002

Polysaccharide part of Proteus mirabilis lipopolysaccharide may be responsible for the stimulation of platelet adhesion to collagen.

Lipopolysaccharide (LPS, endotoxin) is a well-known causative agent of septic shock and disseminated intravascular coagulation. The action of LPS is related to the activation of many types of cells, including blood platelets. We examined the effects of different LPSs from Proteus mirabilis (smooth form LPS S1959 and rough forms LPSs R110 and R45) and fragments of LPS structure (lipid A and polysaccharide part) on platelet adhesion to collagen in the presence or absence of the phoinositide 3-kinase (PI 3-K) inhibitor, wortmannin. We found that all forms of LPS and its fragments caused the stimulation of platelet adhesion to collagen, but the polysaccharide part (PS S1959) was the most important in this action. Wortmannin had no effect on LPS-stimulated platelet adhesion to collagen. We conclude that both lipid A and PS S1959 play important roles in LPS-stimulated platelet adhesion to collagen independent on the PI 3-K action.

Androstadienes↗
PubMed1962

Cytoplasmic DNA synthesis in Amoeba proteus. II. On the behavior and possible nature of the DNA-containing elements.

Nucleic acid-containing particles in the cytoplasm of Amoeba proteus (cf. reference 1) were counted after acridine orange staining. The number of particles per ameba was found to be correlated with cell age and size. Fresh daughters had a mean particle number of 5400, whereas predivision amebae contained around 11,000 particles. Amebae from two other strains contained similar particles. The particles were found to be clustered in fasted cells and redispersed after feeding. A marked increase in the particle population was noted in anucleate fragments. These results, together with those previously presented, suggest that the particles multiply intracellularly. Their nature and their relationship to previous work on nucleic acid labeling in Amoeba are discussed.

Amoeba↗
PubMed1964

CYTOPLASMIC DNA SYNTHESIS IN AMOEBA PROTEUS. 3. FURTHER STUDIES ON THE NATURE OF THE DNA--CONTAINING ELEMENTS.

The application of electron microscope autoradiography to Amoeba proteus cells labeled with tritiated thymidine has permitted the identification of morphologically distinct particles in the cytoplasm as the sites of incorporated DNA precursor. The particles correspond to those previously described from light microscope studies, with respect to both H(3)Tdr incorporation and distribution in centrifugally stratified amoebae. Ingested bacteria differ from the particles, in morphology as well as in the absence of associated label. Attempts to introduce a normal particle labeling pattern by incubating amoebae with labeled sediment derived from used amoeba medium failed. The resultant conclusion, that the particles are maintained in the amoeba by self-duplication, is supported by the presence of particles in configurations suggestive of division.

Amoeba↗
PubMed1957

Electron microscopic observations of amoeba proteus in growth and inanition.

Electron microscopic observations have been made on growing and dividing specimens of Amoeba proteus and also on starving animals. Structures presumably corresponding to the mitochondria, alpha particles, vacuoles, and Golgi material are described. A new entity, designated as a foamy particle, is noted. Descriptions are given of the cytoplasmic and nuclear membranes. During division the inner, thick nuclear membrane component is seen to vanish and the outer membrane persist. Measurements suggest a gradual reappearance of the inner component with growth. Starving animals show a loss of cytoplasmic granularity and an increase in the electron density of mitochondria, presumably due to lipide accumulation.

Amoeba↗
PubMed1966

Basal bodies of bacterial flagella in Proteus mirabilis. II. Electron microscopy of negatively stained material.

This paper investigates further the question of whether the flagella of Proteus mirabilis emerge from basal bodies. The bacteria were grown to the stage of swarmer differentiation, treated lightly with penicillin, and then shocked osmotically. As a result of this treatment, much of the cytoplasmic content and also part of the plasma membrane were removed from the cells. When such fragmented organisms were stained negatively with potassium phosphotungstate, the flagella were found to be anchored-often by means of a hook-in rounded structures approximately 50 mmicro wide, thus confirming Part I of our study. In these rounded structures a more brilliant dot was occasionally observed, which we interpret as being part of the basal granule. A prerequisite for the demonstration of the basal granules within the cells was, however, the removal of both the cytoplasm and the plasma membrane from their vicinity. In some experiments, the chondrioids were "stained" positively by the incorporation into them of the reduced product of potassium tellurite. The chondrioids were here observed to be more or less circular areas from which rodlike structures extended. The chondrioids adhered so firmly to the plasma membrane that they were carried away with it during its displacement by osmotic shocking, while the basal bodies were left behind. This observation disproves our previous suggestion that the flagella might terminate in the chondrioids. The basal bodies often occur in pairs, which suggest that they could be self-reproducing particles.

Cell Differentiation↗
PubMed1960

Electron microscopic studies of mitosis in amebae. I. Amoeba proteus.

Individual organisms of Amoeba proteus have been fixed in buffered osmium tetroxide in either 0.9 per cent NaCl or 0.01 per cent CaCl(2), sectioned, and studied in the electron microscope in interphase and in several stages of mitosis. The helices typical of interphase nuclei do not coexist with condensed chromatin and thus either represent a DNA configuration unique to interphase or are not DNA at all. The membranes of the complex nuclear envelope are present in all stages observed but are discontinuous in metaphase. The inner, thick, honeycomb layer of the nuclear envelope disappears during prophase, reappearing after telophase when nuclear reconstruction is in progress. Nucleoli decrease in size and number during prophase and re-form during telophase in association with the chromatin network. In the early reconstruction nucleus, the nucleolar material forms into thin, sheet-like configurations which are closely associated with small amounts of chromatin and are closely applied to the inner, partially formed layer of the nuclear envelope. It is proposed that nucleolar material is implicated in the formation of the inner layer of the envelope and that there is a configuration of nucleolar material peculiar to this time. The plasmalemma is partially denuded of its fringe-like material during division.

Amoeba↗
PubMed2005

CTX-M-1 extended-spectrum beta-lactamase-producing Proteus mirabilis in Greece.

To examine the dissemination of CTX-M-type extended-spectrum beta-lactamases (ESBLs) in clinical isolates of Proteus mirabilis, 91 nonrepetitive ESBL-producing P. mirabilis were collected from infected patients in a tertiary Greek hospital during September, 2001, to May, 2004. A bla (CTX-M) gene was amplified in one isolate (strain A328), but bla (CTX-M) was not detected in any of the remaining ESBL producers. Sequencing results showed that P. mirabilis A328 produced a CTX-M-1 enzyme while PCR mapping of the genetic element carrying bla (CTX-M-1) revealed that the gene was located downstream of an ISEcp1B element. The cefotaxime resistance determinant was easily transferable and carried on a 70-kb plasmid. The emergence of CTX-M-1- producing P. mirabilis indicates the need for early recognition of such strains to be able to control their spread in our hospital and community environment.

Greece↗
PubMed1976

Variation in urease activity of endemic hospital strains of Proteus rettgeri and Providencia stuartii.

Both urease-positive and urease-negative Proteeae isolated from cross-infected patients in the same hospitals and, in three cases, from the same patients were examined for their biochemical reactions and somatic (O-) antigens. All isolates gave the same reactions in 17 biochemical tests and possessed O-antigens characteristic of Providenic O-type strains 4 or 17. Study of the isolates indicated that endemic strains are capable of undergoing variation in urease activity. In the current classification urease-positive and urease-negative strains are classified as Proteus rettgeri and Providencia stuartii, respectively. The observed variation in urease activity of nosocomial isolates of Proteeae suggests that taxonomy should be modified so that all such strains would be accommodated in a single group.

Antigens, Bacterial↗
PubMed1977

Differential susceptibility of Escherichia coli and Proteus mirabilis to mouse urine and to urea.

The purpose of this investigation was to compare the antimicrobial properties of mouse urine and of urea against Escherichia coli and Proteus mirabilis. Nornal urine was found to inhibit the growth of E. coli and P. mirabilis, whereas urine from diuresing animals permitted multiplication of these bacteria. Addition of urea to urine from diuresing animals restored its bactericidal effect on P. mirabilis but not on E. coli. This bactericidal effect on P. mirabilis was dependent on the additive action of high content of urea and high pH and was prevented by the addition of urease inhibitor.

Animals↗
PubMed1978

Factors influencing the therapy of experimental Proteus mirabilis meningitis in rabbits.

The therapy of Proteus mirabilis meningitis with gentamicin alone and in combination with chloramphenicol was studied in a rabbit model. Antibiotics were administered for 8 hr. Samples of serum and cerebrospinal fluid (CSF) obtained simultaneously were assayed at 2-hr intervals for antibiotic concentration and counts of bacteria in CSF. The percentage of penetration ([concentration in CSF divided by concentration in serum] x 100%) of gentamicin ranged from 14% to 23%, but very large dosages were required to kill bacteria in the CSF. Although the minimal bactericidal concentration (MBC) of gentamicin was 1 microgram/ml, killing in vivo occurred only when concentrations in CSF were 10--30 times the MBC. The high concentration required for bactericidal activity in vivo may be explained by the reduced pH of infected CSF (mean pH, 6.98; range, 6.69--7.18). The bactericidal action of gentamicin was abolished by the simultaneous administration of chloramphenicol. Titers of bacteria in CSF were reduced 2.60 log10 (mean) with gentamicin therapy vs. 0.92 log10 (mean) with combination (P less than 0.01).

Animals↗
PubMed1990

Antibacterial effect of meropenem and imipenem on Proteus mirabilis.

Phase-contrast microscopy, killing-curves and turbidimetric growth-curves were used in a comparative study of the antibacterial effects of a new carbapenem, meropenem (SM 7338) and imipenem on five strains of Proteus mirabilis. Despite the low MIC (0.2 mg/l) of imipenem for the five strains included in our study, the MBC remained relatively high (4.4 mg/l). During the first few hours of incubation, imipenem induced large lemon-shaped cells while the turbidity increased without substantial changes in culture viability. Later, most of the cell-wall deficient bacteria generated small spheroplasts until the antibiotic concentration exceeded 32 times the MIC. The MIC of meropenem was lower (0.03 mg/l) with an MBC (0.08 mg/l) very close to the MIC. Meropenem also induced large bodies but these cell-wall deficient bacteria did not generate small round bodies as observed with imipenem. In conclusion, imipenem produced in strains of Pr. mirabilis an amdinocillin-like change in cell morphology, responsible for the discrepancies observed between MIC and MBC. This effect was not observed with meropenem.

Imipenem↗