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PubMed1996

Proteus mirabilis ambient-temperature fimbriae: cloning and nucleotide sequence of the aft gene cluster.

Uropathogenic Proteus mirabilis produces at least four types of fimbriae. Amino acid sequences from two peptides, derived by tryptic digestion of the structural subunit of one type of these fimbriae, the ambient-temperature fimbriae, were determined: NVVPGQPSSTQ and LIEGENQLNYNA. PCR primers, based on these sequences and that of the N terminus, were used to amplify a 359-bp fragment. A cosmid clone, isolated from a P. mirabilis genomic library by hybridization with the 359-bp PCR product, was used to determine the nucleotide sequence of the atf gene cluster. A 3,903-bp region encodes three polypeptides: AtfA, the structural subunit; AtfB, the chaperone; and AtfC, the outer membrane molecular usher. No fimbria-related genes are evident either 5' or 3' to the three contiguous genes. AtfA demonstrates significant amino acid sequence identity with type 1 major fimbrial subunits of several enteric species. The 359-bp PCR product hybridized strongly with all Proteus isolates (n = 9) and 25% of 355 Escherichia coli isolates but failed to hybridize with any of 26 isolates among nine other uropathogenic species. Ambient-temperature fimbriae of P. mirabilis may represent a novel type of fimbriae of enteric species.

Amino Acid Sequence↗
PubMed1975

Variation in expression of sex factor genes in the Proteus-Providencia group relative to Escherichia coli.

Several instances of anomalous expression of genes introduced from Escherichia coli K-12 into Proteus mirabilis have been described. It is shown here that control of sex pilus synthesis directed by the F-like R factor R1 and its depressed derivatives R1-16 (O-C) and R1-19 (i-minus) is also anomalous in P. mirabilis. Piliation in cells bearing the depressed plasmids is expressed at a lower level than in E. coli K-12, and repression is absent in R1-carrying cells. Preliminary results show a similar effect in Providencia. In Proteus morganii, a similarly reduced level of piliation in R1-16-+ or R1-19-+ cultures is observed, but an intermediate level of repression occurs in R1-+ cultures. Less extensive data suggest that expression of the sex factor genes of an R factor of the N incompatibility group differs far less between E. coli and P. mirabilis hosts. Possible bases for these effects are discussed.

Coliphages↗
PubMed1977

Purification and properties of beta-lactamase from Proteus morganii.

The cephalosporin beta-lactamase was purified from a strain of Proteus morganii that showed resistance to beta-lactam antibiotics and produced the enzyme constitutively. The purified enzyme preparation gave a single protein band on polyacrylamide gel electrophoresis and consisted of a single polypeptide of molecular weight 38,000 to 40,000 from gel filtration of Sephadex G-100 and sodium dodecyl sulfate-acrylamide gel electrophoresis, its isoelectric point being pH 7.2 No cysteine residue was found in its amino acid composition. The specific activity was 190 mumol/min per mg of the purified enzyme protein for the hydrolysis of cephaloridine, the optimal pH was about 8.5 and the optimal temperature was 50 degrees C. Antibodies against the purified beta-lactamase inhibited not only the enzyme activity of the purified preparation, but also the enzyme activity of all of the other strains of P. morganii so far tested, regardless of whether the modes of their production were inducible or constitutive. None of the beta-lactamases produced by beta-lactam antibiotic-resistant strains of other species of Proteus was affected at all by the antibodies, thus showing that the purified cephalosporin beta-lactamase was of the species-specific type. The enzymological properties of the preparation have been compared with those of beta-lactamases derived from other gram-negative enteric bacteria.

Amidohydrolases↗
PubMed1985

Resistance to chloramphenicol in Proteus mirabilis by expression of a chromosomal gene for chloramphenicol acetyltransferase.

Proteus mirabilis PM13 is a well-characterized chloramphenicol-sensitive isolate which spontaneously gives rise to resistant colonies on solid media containing chloramphenicol (50 micrograms ml-1) at a plating efficiency of 10(-4) to 10(-5). Such chloramphenicol-resistant colonies exhibit a novel phenotype with respect to chloramphenicol resistance. When a single colony grown on chloramphenicol agar is transferred to liquid medium and grown in the absence of antibiotic for 150 generations, a population of predominantly sensitive cells arises. This mutation-reversion phenomenon has been observed in other Proteus species and Providencia strains, wherein resistance has been shown to be mediated in each case by the enzyme chloramphenicol acetyltransferase. The cat gene responsible for the phenomenon is chromosomal and can be cloned from P. mirabilis PM13 with DNA prepared from cells grown in the absence or the presence of chloramphenicol. Recombinant plasmids which confer resistance to chloramphenicol carry an 8.5-kilobase PstI fragment irrespective of the source of host DNA. The location of the cat gene within the PstI fragment was determined by Southern blotting with a cat consensus oligonucleotide corresponding to the expected amino acid sequence of the active site region of chloramphenicol acetyltransferase, and the direction of transcription was deduced from homology with the type I cat variant.

Acetyltransferases↗
PubMed1991

Transposon mutagenesis in Proteus mirabilis.

A technique of transposon mutagenesis involving the use of Tn5 on a suicide plasmid was developed for Proteus mirabilis. Analysis of the resulting exconjugants indicated that Tn5 transposed in P. mirabilis at a frequency of ca. 4.5 x 10(-6) per recipient cell. The resulting mutants were stable and retained the transposon-encoded antibiotic resistance when incubated for several generations under nonselective conditions. The frequency of auxotrophic mutants in the population, as well as DNA-DNA hybridizaiton to transposon sequences, confirmed that the insertion of the transposon was random and the Proteus chromosome did not contain significant insertional hot spots of transposition. Approximately 35% of the mutants analyzed possessed plasmid-acquired ampicillin resistance, although no extrachromosomal plasmid DNA was found. In these mutants, insertion of the Tn5 element and a part or all of the plasmid had occurred. Application of this technique to the study of swarmer cell differentiation in P. mirabilis is discussed.

DNA Transposable Elements↗
PubMed1995

Proteus mirabilis urease: operon fusion and linker insertion analysis of ure gene organization, regulation, and function.

Urease is an inducible virulence factor of uropathogenic Proteus mirabilis. Although eight contiguous genes necessary for urease activity have been cloned and sequenced, the transcriptional organization and regulation of specific genes within the Proteus gene cluster has not been investigated in detail. The first gene, ureR, is located 400 bp upstream and is oriented in the direction opposite the other seven genes, ureDABCEFG. The structural subunits of urease are encoded by ureABC. Previously, UreR was shown to contain a putative helix-turn-helix DNA-binding motif 30 residues upstream of a consensus sequence which is a signature for the AraC family of positive regulators; this polypeptide is homologous to other DNA-binding regulatory proteins. Nested deletions of ureR linked to either ureD-lacZ or ureA-lacZ operon fusions demonstrated that an intact ureR is required for urea-induced synthesis of LacZ from either ureA or ureD and identified a urea-regulated promoter in the ureR-ureD intergenic region. However, lacZ operon fusions to fragments encompassing putative promoter regions upstream of ureA and ureF demonstrated that no urea-regulated promoters occur upstream of these open reading frames; regions upstream of ureR, ureE, and ureG were not tested. These data suggest that UreR acts as a positive regulator in the presence of urea, activating transcription of urease structural and accessory genes via sequences upstream of ureD. To address the role of the nonstructural regulatory and accessory genes, we constructed deletion, cassette, and linker insertion mutations throughout the ure gene cluster and determined the effect of these mutations on production and regulation of urease activity in Escherichia coli. Mutations were obtained, with locations determine by DNA sequencing, in all genes except ureA and ureE. In each case, the mutation resulted in a urease-negative phenotype.

Bacterial Proteins↗
PubMed1996

Periodic phenomena in Proteus mirabilis swarm colony development.

Proteus mirabilis colonies exhibit striking geometric regularity. Basic microbiological methods and imaging techniques were used to measure periodic macroscopic events in swarm colony morphogenesis. We distinguished three initial phases (lag phase, first swarming phase, and first consolidation phase) followed by repeating cycles of subsequent swarming plus consolidation phases. Each Proteus swarm colony terrace corresponds to one swarming-plus-consolidation cycle. The duration of the lag phase was dependent upon inoculation density in a way that indicated the operation of both cooperative and inhibitory multicellular effects. On our standard medium, the second and subsequent swarm phases displayed structure in the form of internal waves visible with reflected and dark-field illumination. These internal waves resulted from organization of the migrating bacteria into successively thicker cohorts of swarmer cells. Bacterial growth and motility were independently modified by altering the composition of the growth medium. By varying the glucose concentration in the substrate, it was possible to alter biomass production without greatly affecting the kinetics of colony surface area expansion. By varying the agar concentration in the substrate, initial bacterial biomass production was unaffected but colony expansion dynamics were significantly altered. Higher agar concentrations led to slower, shorter swarm phases and longer consolidation phases. Thus, colony growth was restricted by higher agar concentrations but the overall timing of the swarming-plus-consolidation cycles remained constant. None of a variety of factors which had significant effects on colony expansion altered terracing frequencies at 32 degrees C, but the length of the swarming-plus-consolidation cycle was affected by temperature and medium enrichment. Some clinical isolates displayed significant differences in terracing frequencies at 32 degrees C. Our results defined a number of readily quantifiable parameters in swarm colony development. The data showed no connection between nutrient (glucose) depletion and the onset of different phases in swarm colony morphogenesis. Several observations point to the operation of density-dependent thresholds in controlling the transitions between distinct phases.

Agar↗
PubMed1997

The rtn gene of Proteus vulgaris is actually from Escherichia coli.

The rtn gene, identified as coming from Proteus vulgaris ATCC 13315, is present in Escherichia coli K-12, and over a 440-bp region of rtn is identical to the published Proteus sequence, with the exception of a single G insertion. It was not possible to verify the presence of rtn in P. vulgaris.

Base Sequence↗
PubMed1962

Urease activity of Proteus species in filtered compared with autoclaved urea media.

Hatch, M. H. (Brown University, Providence, R.I.) and C. A. Stuart. Urease activity of Proteus species in filtered compared with autoclaved urea media. J. Bacteriol. 83:1119-1123. 1962.-Urease activity of a number of strains of four Proteus species was compared in a filtered medium and an autoclaved medium. Various amounts of saline suspensions of the organisms were used as inocula for the two media. In some experiments Seitz-filtered yeast extract was added to autoclaved basal urea medium. All tests were incubated at 35 C and read 8, 12, 24, and 48 hr after inoculation. The filtered medium appeared superior to the autoclaved medium, particularly when small inocula were employed. Under these conditions, many tests with all four species were negative in the autoclaved medium at 48 hr, in contrast to 100% positive reactions in the filtered medium with all species except P. morganii. The experiments in which Seitz-filtered yeast extract was added to autoclaved basal urea medium suggested that both destruction of growth-promoting substances in the yeast extract and production of conditions inhibitory for growth during autoclaving might be involved in the differences observed between the two media.

Culture Media↗
PubMed1964

Glucosamine-6-phosphate degradation by Proteus vulgaris and isolation of phosphoglucosaminisomerase.

Aron, H. (University of California, Santa Barbara), H. H. Yonenaka, and H. I. Nakada. Glucosamine-6-phosphate degradation by Proteus vulgaris and isolation of phosphoglucosaminisomerase. J. Bacteriol. 87:1123-1128. 1964.-The presence of the enzyme, phosphoglucosaminisomerase, was demonstrated in a strain of Proteus vulgaris. Fructose-6-phosphate and ammonia were shown to be the primary reaction products. The optimal pH was 7.2 with a broad peak. This differs from previously reported bacterial phosphoglucosaminisomerases which had a pH optimum of about 5.8. Other properties of the enzyme are presented.

Ammonia↗
PubMed1965

Inhibitory action of selenite on Escherichia coli, Proteus vulgaris, and Salmonella thompson.

Weiss, K. F. (Iowa State University, Ames), J. C. Ayres, and A. A. Kraft. Inhibitory action of selenite on Escherichia coli, Proteus vulgaris, and Salmonella thompson. J. Bacteriol. 90:857-862. 1965.-The resistance of three microorganisms, Escherichia coli (ISU-41), Proteus vulgaris (ISU-37c), and Salmonella thompson (ISU-86-2), to increasing concentrations of selenite was determined. E. coli was completely inhibited by 1.25% sodium hydrogen selenite, and 0.25% sodium hydrogen selenite caused a pronounced lag. P. vulgaris survived selenite concentrations of over 3%. S. thompson was inhibited completely by 3% selenite but not by 2.5%, although there was a considerable lag and a decrease in total growth. The relationship of growth, uptake, and reduction of selenite was determined. The susceptible E. coli incorporated up to twice as much selenium as did the other two organisms during the early stages of incubation. Radioautographs of seleno analogues of sulfur-containing amino acids revealed the presence of seleno-cystine in all three organisms, and seleno-methionine in E. coli. Compounds having R(F) values corresponding to possible oxidation products of seleno-methionine were present in the hydrolysates of P. vulgaris and S. thompson. Kinetic aspects of selenite uptake, rather than the ultimate localization of selenite in the cell protein, appear to be the factors that determine the degree of resistance or of susceptibility to selenite.

Bacterial Proteins↗
PubMed1965

Basal structure and attachment of flagella in cells of Proteus vulgaris.

Abram, Dinah (Purdue University, Lafayette, Ind.), Henry Koffler, and A. E. Vatter. Basal structure and attachment of flagella in cells of Proteus vulgaris. J. Bacteriol. 90:1337-1354. 1965.-The attachment of flagella to cells of Proteus vulgaris was studied electron microscopically with negatively stained and shadow-cast preparations of ghosts from standard cultures and from special cultures that produced "long forms." The flagellum, the basal portion of which is hooked, arises within the cell from a nearly spherical structure, 110 to 140 A in diameter. This structure appears to be associated with the cytoplasmic membrane; it may be a part of the membrane or a separate entity that lies just beneath the membrane. Flagella associated with cell walls free from cytoplasmic membrane frequently have larger bodies, 200 to 700 A in diameter, associated with their base. These structures probably consist at least partly of fragments of the cytoplasmic membrane, a portion of which folds around a smaller structure. Flagella in various stages of development were observed in long forms of P. vulgaris cells grown at low temperature. The basal structure of these flagella was similar to that of the long or "mature" flagella. Strands connecting the basal structures were observed in ghosts of long forms; these strands appear to be derived from the cytoplasmic membrane. Flagella were found to be attached to fragments of cell wall and to cytoplasmic membrane in a similar manner as they are attached to ghosts. In isolates of flagella that have been separated from the cells mechanically, the organelles often terminate in hooks which almost always appear naked, but have a different fine structure than the flagellum proper.

Flagella↗
PubMed1966

Fluorescence and viability of Proteus mirabilis stained directly with fluorescein isothiocyanate.

Grunberg, E. (Hoffman-La Roche, Inc., Nutley, N.J.), and R. Cleeland. Fluorescence and viability of Proteus mirabilis stained directly with fluorescein isothiocyanate. J. Bacteriol. 92:23-27. 1966.-Washed cell suspensions of Proteus mirabilis, under the proper conditions, stained well with fluorescein isothiocyanate with little or no loss of cell viability. The speed and intensity of the reaction was dependent on both the concentration of dye and pH. Within a range of pH 3.0 to 10.0, staining was most rapid at pH 5.0 to 6.0, with a slower and less intense reaction occurring at the other pH values. As the concentration of dye at either pH 5.0 or 9.0 was increased from 10 to 1,000 mug/ml, there was an increase in the rate of staining but a decrease in cell viability. After 24 hr of incubation at 4 C, pH 5.0, and a dye concentration of 10 mug/ml, all cells were stained, the majority exhibiting intense fluorescence with little or no loss of viability noted. In preliminary experiments with Staphylococcus aureus, similar results were obtained. Of various other fluorescent dyes tested, only rhodamine isothiocyanate was found to give satisfactory staining.

Fluoresceins↗
PubMed1969

Susceptibility to polymyxin B in penicillin G-induced Proteus mirabilis L forms and spheroplasts.

A polymyxin B-resistant strain of Proteus mirabilis was converted into L forms and spheroplasts in the presence of penicillin G. This treatment caused a 400-fold increase in polymyxin B susceptibility. The acquired susceptibility was in the range of the natural susceptibility reported for susceptible gram-negative bacteria ( approximately 1 mug/ml). The high susceptibility to polymyxin B was lost as soon as the spheroplasts and L forms were allowed to reconvert into the bacillary form in penicillin-free media. This behavior is strong evidence that the natural resistance of Proteus strains to polymyxins is due to the impermeability of the outer cell wall structures to these antibiotic substances.

Cell Membrane Permeability↗
PubMed1994

Predictive accuracy of disk diffusion test for Proteus vulgaris and Providencia species against five newer orally administered cephalosporins, cefdinir, cefetamet, cefprozil, cefuroxime, and loracarbef.

Three members of the tribe Proteeae (Proteus vulgaris, Providencia rettgeri, and Providencia stuartii) were tested against five newer orally administered cephalosporins (cefdinir, cefprozil, cefuroxime, cefetamet, and loracarbef) by the disk diffusion and reference broth microdilution methods. One hundred strains of these organisms were tested to confirm the excessive interpretive error rates that previously had been noted for the disk diffusion test. The results indicate that the suggested disk diffusion breakpoints for cefetamet and cefuroxime were without serious interpretive errors. In contrast, loracarbef, cefdinir, and cefprozil results exceeded acceptable interpretive error rates, with very major (false-susceptible) errors of 4, 5, and 9% respectively. Loracarbef currently has a warning in the National Committee for Clinical Laboratory Standards table footnotes addressing this problem. We recommend including cefdinir and cefprozil in the list of compounds requiring this warning. In addition, MICs of cefazolin, cefaclor, and cephalothin were determined to establish whether a class MIC concept to predict susceptibility for these agents was possible. When the indole-positive Proteus strains are tested, cefazolin MICs can be used to predict MICs of all tested orally administered cephems (8 to 13% total errors, with only a 0 to 1% very major error.

Administration, Oral↗
PubMed1977

Unusual Enterobacteriaceae. "Proteus rettgeri" that "change" into Providencia stuartii.

A blood culture bottle from a patient with bacteremia contained both Proteus rettgeri biogroup 5 and Providencia stuartii (described in Bergey's Manual of Determinative Bactiology [8th ed., 1974] as Proteus inconstans), which had the same unusual antibiotic resistance pattern. Single colonies of this P. rettgeri biogroup 5 isolate were shown to produce urea- clones. If current taxonomy is used, the strain changed from P. rettgeri to P. stuartii in the laboratory and probably also in the patient. Urea- clones were also found in three of six other strains of P. rettgeri biogroup 5. No urea-negative clones were found in two isolates each of P. rettgeri biogroups 1 and 3. Previous data from deoxyribonucleic acid-deoxyribonucleic acid hybridization, biochemical reactions, and serological cross-reactions all have indicated that the taxon now called P. rettgeri biogroup 5 should be classified as P. stuartii urea+. We propose that this taxonomic change be made. Urease production is probably plasmid mediated in P. stuartii urea+ and can easily be lost, as shown in our case report and in three stock cultures. Urea hydrolysis will no longer be the key test for differentiating P. rettgeri from P. stuartii. Rather, acid production from trehalose, D-arabitol, adonitol, and D-mannitol will be the key tests. Whereas P. rettgeri is usually trehalose-, D-arabitol+, adonitol+, and D-mannitol+, P. stuartii has the opposite reactions.

Aged↗
PubMed2000

Proteus syndrome and immunodeficiency.

A 10 year old boy with Proteus syndrome presented with a pericardial effusion of unknown aetiology. Immunological investigation revealed low serum IgG and IgA, accompanied by low levels of specific antibodies to pneumococcal and haemophilus type B polysaccharides. Circulating lymphocyte surface marker profile revealed T and B cell lymphopenia. This is the first report of hypogammaglobulinaemia occurring in the Proteus syndrome.

Agammaglobulinemia↗
PubMed1997

Non-operative management of a splenic laceration in a patient with the Proteus syndrome.

An adult patient with the Proteus syndrome sustained a grade III splenic laceration after falling off a horse. Clinical features of this rare disorder include subcutaneous and visceral hamartomatous tumours. The patient also suffered from chronic intravascular coagulation associated with extensive haemangiomatosis (Kasabach-Merritt syndrome). Considering the visceral anomalies and abnormal coagulation, a non-operative approach was preferred despite considerable transfusion requirement, and the patient successfully underwent embolisation of the splenic artery. This is the first reported case of splenic injury in a patient with Proteus syndrome.

Adult↗