stereo-specific synthesis of 3-trifluoromethylcephalosporin derivative by microbial acylase.cephalosporin acylase (ec obtained from kluyvera citrophila atcc 21285 was found to catalyze synthesis of 7-[2-(2-thienyl)acetamido]-3-trifluoromethyl-3-cephem-4-carboxylic acid from methyl thienylacetate and dl-7-amino-3-trifluoromethyl-3-cephem-4-carboxylic acid. the enzymatically-synthesized compound showed [alpha]25 d + 42.7 degrees (c 0.058, meoh) and its biological activity was about twice as much as that of racemic 7-[2-(2-thienyl)acetamidol]-3-trifluoromethyl-3-cephem-4-carboxy ...1979393680
[numerical taxonomic studies on enterobacteria of surface-water (author's transl)].435 enterobacterial strains of surface-water were tested in 35 physiological characters and classified numerically by a single-linkage procedure. the relations of similarity are shown in a "vernetzungsdiagramm" (connected graph, fig. 1). tab. 1 specifies the characters of the taxa, which were formed graphically. the following facts are the result of this taxonomic classification: 1. 32% of the escherichia group are kcn-positive. in addition it was found that 60% of the e. coli isolated from the ...1978735569
penicillin acylase mutants with altered site-directed activity from kluyvera citrophila.oligonucleotide-directed mutagenesis has been used to obtain specific changes in the penicillin acylase gene from kluyvera citrophila. wild-type and mutant proteins were purified and the kinetic constants for different substrates were determined. mutations in met168 highly decreased the specificity constant of the enzyme for penicillin g, penicillin v and phenylacetyl-4-aminobenzoic acid and the catalytic constant kcat for phenylacetyl-4-aminobenzoic acid. likewise, the phenylmethylsulphonyl-flu ...19901366784
changing glycine 21 for glutamic acid in the beta-subunit of penicillin g acylase from kluyvera citrophila prevents protein penicillin acylase from kluyvera citrophila strain atcc 21,285 consists of two different alpha- and beta-subunits derived from a single precursor by post-translational processing. using the chemical mutagen hydroxylamine we have treated plasmid pykd59 containing the active penicillin acylase gene (pga) from k. citrophila and have generated different point mutant penicillin acylase genes, one producing a maturation deficient precursor. this point mutation has changed the glycine 310 residu ...19921368070
[kluyvera ascorbata infections. apropos 2 cases]. 19921589614
chemical modification of serine at the active site of penicillin acylase from kluyvera citrophila.the site of reaction of penicillin acylase from kluyvera citrophila with the potent inhibitor phenylmethanesulphonyl fluoride was investigated by incubating the inactivated enzyme with thioacetic acid to convert the side chain of the putative active-site serine residue to that of cysteine. the protein product contained one thiol group, which was reactive towards 2,2'-dipyridyl disulphide and iodoacetic acid. carboxymethylcysteine was identified as the n-terminal residue of the beta-subunit of th ...19911764029
trabulsiella guamensis, a new genus and species of the family enterobacteriaceae that resembles salmonella subgroups 4 and 1985 the vernacular name enteric group 90 was coined for a small group of strains that had been referred to our laboratory as probable strains of salmonella but did not agglutinate in salmonella typing antisera. by dna-dna hybridization (hydroxyapatite method, 32p), seven strains of enteric group 90 were found to be closely related (98 to 100% at 60 degrees c and 94 to 100% at 75 degrees c) to the first strain received (0370-85). the relatedness of enteric group 90 to 62 strains of other spec ...19911885744
peritonitis due to kluyvera ascorbata: case report and review.kluyvera, a new genus in the family enterobacteriaceae, was formerly known as enteric group 8 and as api group 1. although kluyvera species have been isolated from various clinical specimens such as sputum, urine, stool, and blood, the clinical significance of these isolates has not been established. recently, we treated a child who developed peritonitis due to kluyvera ascorbata. the repeated isolation of the organism in pure culture from the peritoneal fluid and its isolation from postmortem s ...19902193346
isolation of bacterial strains, which hydrolyze glycyrrhizin and produce glycyrrhezic acid, from soil.we isolated eight bacterial strains which could hydrolyze glycyrrhizin to glycyrrhezic acid. the bacterial strains were identified as three strains of pseudomonas saccharophila, two of plesiomonas sp., one of pseudomonas stutzeri, one of klebsiella pneumoniae subsp. ozaenae and one of kluyvera ascorbata. their capacity for the conversion of glycyrrhizin to glycyrrhezic acid was assayed by high performance liquid chromatography. p. saccharophila 11 was the most effective among the eight strains. ...19902231267
kluyvera mediastinitis following open-heart surgery: a case report.reports of serious infections caused by kluyvera spp. have been rare. a case of kluyvera sp. mediastinitis and bacteremia in a man after open-heart surgery is described. the clinical significance of kluyvera sp. isolates was debated in early descriptions of the organism. more recent reports, as well as the present case, suggest that the pathogenic potential of this organism is being increasingly recognized by clinicians and microbiologists.19902280023
evolution of aromatic amino acid biosynthesis and application to the fine-tuned phylogenetic positioning of enteric bacteria.a comprehensive phylogenetic tree for virtually the entire assemblage of enteric bacteria is presented. character states of aromatic amino acid biosynthesis are used as criteria, and the results are compared with partial trees based upon sequencing of 16s rrna, 5s rrna, and tryptophan leader peptide. three major clusters are apparent. enterocluster 1 possesses a gene fusion (trpg-trpd) encoding anthranilate synthase: anthranilate 5-phosphoribosylpyrophosphate phosphoribosyltransferase of tryptop ...19902298692
thermodynamic profiles of penicillin g hydrolysis catalyzed by wild-type and met----ala168 mutant penicillin acylases from kluyvera citrophila.the met-168 residue in penicillin acylase from kluyvera citrophila was changed to ala by oligonucleotide site-directed mutagenesis. the ala-168 mutant exhibited different substrate specificity than wild-type and enhanced thermal stability. the thermodynamic profiles for penicillin g hydrolysis catalyzed by both enzymes were obtained from the temperature dependence of the steady-state kinetic parameters km and kcat. the high values of enthalpy and entropy of activation determined for the binding ...19902306469
acute pyelonephritis due to a kluyvera species in a child.a kluyvera sp. was recovered from the urine of a previously healthy 5-year-old child with clinical and laboratory evidence of acute pyelonephritis. this pathogen is usually a saprophyte and even when recovered in humans it is ordinarily considered an opportunistic pathogen. only two other cases of kluyvera infection have been described in immunocompetent individuals. the case presented further supports the finding that this bacterium can cause severe disease even in previously healthy, immunocom ...19902351144
kspi, a novel isoschizomer of sacii from kluyvera species recognizing 5'-ccgc/gg-3'. 19892587269
ksp632i, a novel class-iis restriction endonuclease from kluyvera sp. strain 632 with the asymmetric hexanucleotide recognition sequence: 5'-ctcttc(n)1-3' 3'-gagaag(n)4-5'.a new class-iis restriction endonuclease, ksp632i, with novel sequence specificity has been discovered in a non-pathogenic species of kluyvera. the presence of only a single site-specific activity in this kluyvera sp. strain 632 enables ksp632i to be isolated in highly purified form free of contaminating nucleases. ksp632i recognition sites and cleavage positions were deduced using experimental and computer-assisted mapping and sequencing. the cleavage specificity corresponds to the sequence 5'- ...19882843429
complete nucleotide sequence of the penicillin acylase gene from kluyvera citrophila.the penicillin acylase (pac) from kluyvera citrophila atcc21285 has been purified to homogeneity and found to be composed of two non-identical subunits of 23 and 62 kda, in contrast with the previous findings [shimizu et al., agr. biol. chem. 39 (1975) 1655-1661]. the nucleotide (nt) sequence of the k. citrophila pac gene contained in the 3-kb pvui-hindiii fragment of pkap1 [garcía and buesa, j. biotechnol. 3 (1986) 187-195] has been determined, showing that it encodes a protein of 844 amino aci ...19863032748
kluyvera species soft tissue infection: case report and review.a soft tissue infection caused by kluyvera species in a previously healthy woman is described. successful treatment required incision and drainage of the wound in addition to administration of antibiotics. kluyvera species are indole positive, voges-proskauer negative members of the family enterobacteriaceae. previous reports of infection due to kluyvera species suggest that the organism is never more than an opportunistic pathogen; however, we report the first case of infection in a previously ...19883068255
[the aerobic intestinal flora of the microchiropteran bat chaerephon pumila in madagascar].from stools of 88 malagasy insect eater bats chaerephon pumila, a large amount of bacterial strains were isolated. twenty different species were recognized, most of them belonged to enterobacteriaceae family. eight strains were identified as salmonella enterica subsp. enterica o48: -; 1.5, despite many atypical characters. strains of salmonella enteritidis, koserella trabulsii, kluyvera sp., odc negative serratia marcescens, atypical hafnia alvei... were also identified.19883240566
[coproculture of the animals at the zoological park of tananarive with isolation of bacteria of the genera shigella, kluyvera, pseudomonas, xanthomonas]. 19883242428
a kluyvera cryocrescens strain from a gall-bladder infection.the isolation and the identification of a pure-culture kluyvera cryocrescens strain in a gall-bladder pus specimen from a 76-year-old woman with acute cholecystitis is described. this is the first reported recovery of a k. cryocrescens strain from such a sample.19883356228
kluyvera: a case report of urinary tract infection and sepsis. 19883368262
a survey of the aerobic bacteria in the feces of captive raptors.feces of 47 captive raptors belonging to the order falconiformes or strigiformes were cultured for bacteria. gram-negative bacteria, which were cultured from the feces of 45 of the 47 raptors, were the most common isolates. a wide variety of species were identified, including a newly described genus (moellerella wisconsensis), two newly described species (escherichia fergusonii and proteus penneri), and a member of a newly described enteric group (cdc enteric group 41). additional organisms iden ...19883382380
the phylogenetic origin of the bifunctional tyrosine-pathway protein in the enteric lineage of bacteria.because bifunctional enzymes are distinctive and highly conserved products of relatively infrequent gene-fusion events, they are particularly useful markers to identify clusters of organisms at different hierarchical levels of a phylogenetic tree. within the subdivision of gram-negative bacteria known as superfamily b, there are two distinctive types of tyrosine-pathway dehydrogenases: (1) a broad-specificity dehydrogenase (recently termed cyclohexadienyl dehydrogenase [cdh]) that can utilize ei ...19883386529
differentiation of kluyvera cryocrescens from kluyvera ascorbata by irgasan susceptibility testing.from the faeces of a diarrhoeic patient, we isolated a strain of kluyvera ascorbata on cefsulodin-irgasan-novobiocin (cin) agar, a highly selective medium used for yersinia enterocolitica. since no selective media have been described for kluyvera spp., we tested 5 strains each of k. ascorbata and k. cryocrescens for their ability to grow on cin agar. k. ascorbata exhibited an inhibition on cin of less than 10% cfu compared to blood agar, whereas k. cryocrescens did not grow at all even with inoc ...19863426156
[isolation of kluyvera ascorbata from madagascan lemurs, healthy carriers of this unusual enterobacterium].six strains of kluyvera ascorbata--an unusual species in the family enterobacteriaceae--were isolated from six healthy lemurs, located in tananarive's zoological garden. their bacteriological characters are reported and compared with those of levinea and escherichia coli. their occurrence and significance in animals are discussed.19873450439
broviac catheter infection with kluyvera cryocrescens: a case report.kluyvera cryocrescens was isolated from a blood culture drawn from a patient with a broviac catheter-related infection. k. cryocrescens has been considered an opportunistic pathogen but has not previously been associated with central venous catheter infections.19873597755
rapid catalase supplemental test for identification of members of the family enterobacteriaceae.a simple, rapid, semiquantitative slide catalase test useful for differentiating members of the family enterobacteriaceae is described. judging by the time required for appearance of oxygen bubbles in 3% hydrogen peroxide, the immediate catalase reactors were yersinia, serratia, proteus, morganella, providencia, cedecea, and hafnia spp. the delayed catalase reactors were escherichia, shigella, klebsiella, enterobacter, salmonella, citrobacter, edwardsiella, kluyvera, and tatumella spp. this info ...19873818934
first strains of the genus kluyvera in czechoslovakia.fourteen of 21 strains isolated from stools, urine specimens and the hospital environment were identified as kluyvera. all of these 14 strains corresponded with the literary description of the genus kluyvera and were identical with two reference strains except that one of them failed to utilize sodium acetate within 7 days. one strain (no. 23441) produced massive growth on jordan's tartrate, which some kluyvera do. important in differentiating indole- and simmons' citrate-negative kluyvera strai ...19854060923
catabolism of hamamelose. the anaerobic dissimilation of d-hamamelose by kluyvera citrophila 627. 19744452358
enzymatic synthesis of d(-)-alpha-aminobenzylpenicillin by kluyvera citrophila. 19715581352
purification and properties of hamamelosekinase.hamamelosekinase (atp:hamamelose 2(1)-phosphotransferase) was purified from a crude extract of kluyvera citrophila 627 (enterobacteriaeceae) which has been grown on d-hamamelose. ammonium-sulfate fractionation and twofold chromatography on deae-cellulose resulted in a 51-fold purification of the enzyme. neither glucosekinase nor significant atpase activity could be detected in the pure preparation. besides d-hamamelose only d-hamamelitol was utilized as a substrate; however, the latter was phosp ...19806249593
enzymatic profile of kluyvera species.kluyvera, a proposed genus formerly known as enteric group 8, was found to have similar enzyme profiles among the present 3 groups. kluyvera species group 3 showed the most heterogeneous enzyme reactions.19846381088
colonization by or diarrhea due to kluyvera species. 19827054314
kluyvera, a new (redefined) genus in the family enterobacteriaceae: identification of kluyvera ascorbata sp. nov. and kluyvera cryocrescens sp. nov. in clinical specimens.kluyvera is proposed as a new genus for the group of organisms formerly known as enteric group 8 (synonym = api group 1). strains of kluyvera share the properties of most members of the family enterobacteriaceae: they are gram-negative rods, motile with peritrichous flagella, catalase positive, and oxidase negative; they grow on macconkey agar, ferment d-glucose with the production of acid and gas, and are susceptible to many antibiotics. strains are usually indole positive, methyl red positive, ...19817240403
new insights on the specificity of penicillin contrast with the general thought that penicillin g acylases (pgas) were only able to hydrolyse amides or esters of higly hydrophobic acids, we have demonstrated that the pga from kluyvera citrophila catalysed the hydrolysis of 4-nitrophenyl esters of acetic, propionic, butyric and valeric acids. values of kcat. and kcat./km were greatest for the first compound and less than values for benzylpenicillin by factors of 30 and 7, respectively. 4-nitrophenyl acetate was hydrolysed faster than 2-ni ...19957826381
changing the substrate specificity of penicillin g acylase from kluyvera citrophila through selective pressure.escherichia coli (mut, mutd, leu-) cells transformed with plasmid pykd59 harbouring the pac gene encoding penicillin acylase (pa) from kluyvera citrophila atcc 21285 were exposed to environmental conditions that made expression of this enzyme essential for growth. under these conditions, spontaneous mutants were isolated that used adipyl-l-leucine as the sole source of l-leucine. dna sequencing of the mutant pac genes identified a transversion mutation of thymine to guanine at position 1163. thi ...19947980457
ph studies to elucidate the chemical mechanism of penicillin acylase from kluyvera citrophila.the variation with ph of the kinetic parameters of penicillin acylase from kluyvera citrophila has been used to gain information about the chemical mechanism of the reaction catalysed by the enzyme. the ph-dependence of log (v/km) for penicillin g showed that a group with a pk value over 4.7 must be deprotonated and that a group with a pk value over 9.7 must be protonated in the free enzyme for activity. the solvent perturbation and temperature studies indicated that these groups are respectivel ...19938338640
characterization of an escherichia coli aromatic hydroxylase with a broad substrate range.the hpab gene encoding an aromatic hydroxylase of escherichia coli atcc 11105, a penicillin g acylase-producing strain, has been cloned and expressed in e. coli k-12. this gene was located near the paca gene coding for penicillin g acylase. the hydroxylase has a molecular mass of 59,000 da, uses nadh as a cosubstrate, and was tentatively classified as a 4-hydroxyphenylacetic acid hydroxylase, albeit it exhibited a rather broad substrate specificity acting on different monohydric and dihydric phe ...19938458860
inactivation of penicillin acylase from kluyvera citrophila by n-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline: a case of time-dependent non-covalent enzyme inhibition.penicillin acylase (pa) from kluyvera citrophila was inhibited by n-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline (eedq), a specific carboxy-group-reactive reagent. enzyme activity progressively decreased to a residual value depending on eedq concentration. neither enzymic nor non-enzymic decomposition of eedq is concomitant with pa inactivation. moreover, enzyme re-activation is achieved by chromatographic removal of eedq, ph increase or displacement of the reagent with penicillin g. it was then ...19938489517
immunological relatedness of the lamb proteins among members of enterobacteriaceae.we have studied the immunological relatedness of lamb proteins from a wide range of enterobacterial species, using antibodies directed against denatured escherichia coli k12 and klebsiella pneumoniae lamb proteins (lambe.c. and lambk.p., respectively), and anti-peptide antibodies directed against 10 distinct loops of lamb from e. coli k12 predicted to protrude either side of the outer membrane. we have shown that a protein immunologically related to lambe.c. and lambk.p. was present in all membe ...19938515243
identification of tonb homologs in the family enterobacteriaceae and evidence for conservation of tonb-dependent energy transduction complexes.the transport of fe(iii)-siderophore complexes and vitamin b12 across the outer membrane of escherichia coli requires the tonb-dependent energy transduction system. a set of murine monoclonal antibodies (mabs) was generated against an e. coli trpc-tonb fusion protein to facilitate structure and function studies. in the present study, the epitopes recognized by these mabs were mapped, and their distribution in gram-negative organisms was examined. cross-species reactivity patterns obtained agains ...19968631714
rapid burst kinetics in the hydrolysis of 4-nitrophenyl acetate by penicillin g acylase from kluyvera citrophila. effects of mutation f360v on rate constants for acylation and de-acylation.the kinetics of release of 4-nitrophenol were followed by stopped-flow spectrophotometry with two 4-nitrophenyl ester substrates of penicillin g acylase from kluyvera citrophila. with the ester of acetic acid, but not of propionic acid, there was a pre-steady-state exponential phase, the kinetics of which were inhibited by phenylacetic acid (a product of hydrolysis of specific substrates) to the extent predicted from ki values. this was interpreted as deriving from rapid formation (73 mm-1.s-1) ...19968687381
a case of kluyvera cryocrescens peritonitis in a capd patient. 19968761550
[utility of pyrrolidonyl-arylamidase detection for typing enterobacteriaceae and non-fermenting gram-negative bacteria].detection of pyrrolidonyl-aryl-amidase activity (pyr) is an important tool to identify gram-positive cocci, such as staphylococci, enterococci, streptococci, and other related genera. however, only few studies evaluating its usefulness with gram-negative rods have been published. thus, a prospective study including 542 and 215 unique clinical isolates of enterobacteriaceae and non-fermentative gram-negative rods, respectively, was undertaken. strains were identified by conventional methods. pyr ...19958850133
identification of the pac promoter from kluyvera citrophila.the nucleotide sequence of the 5'-terminal region of the pac gene encoding the penicillin g acylase from kluyvera citrophila atcc 21285 has been determined. the transcriptional start site has been identified by primer extension analysis in a different position to that previously found for the homologous pac gene of escherichia coli w atcc 11105. two nucleotide changes in the -35 box appear to be responsible of the promoter displacement in k. citrophila. a putative upstream promoter element (a+t- ...19979198278
[kluyvera ascorbata bacteremia]. 19979235422
kluyvera bacteriophage kvp1: a new member of the podoviridae family phylogenetically related to the coliphage t7.a dna containing bacteriophage, kvp1, was isolated from the water of a very polluted river, the matanza river, near the central district of buenos aires city. this bacteriophage infects bacteria belonging to the kluyvera cryocrescens species (strain 21 g) isolated from the same river. kvp1 is a lytic bacteriophage and its propagation characteristics are: burst size 30, latent period 13 min and rise period 10 min. morphologically, kvp1 is a small icosahedral bacteriophage, 59.1 nm in diameter, wh ...19979381794
a plant growth-promoting bacterium that decreases nickel toxicity in seedlingsa plant growth-promoting bacterium, kluyvera ascorbata sud165, that contained high levels of heavy metals was isolated from soil collected near sudbury, ontario, canada. the bacterium was resistant to the toxic effects of ni2+, pb2+, zn2+, and cro4-, produced a siderophore(s), and displayed 1-aminocyclopropane-1-carboxylic acid deaminase activity. canola seeds inoculated with this bacterium and then grown under gnotobiotic conditions in the presence of high concentrations of nickel chloride were ...19989758782
kluyvera cryocrescens finger infection: case report and review of eighteen kluyvera infections in human beings.we report a case of soft tissue infection with kluyvera cryocrescens and a critical review of kluyvera infections. a 31-year-old diabetic man used a new chemical for stripping the floor with his bare hands. two days later he developed a blister on a finger which progressed to tenosynovitis in spite of intravenous nafcillin therapy. after 11 days culture and sensitivity results dictated treatment with intravenous ticarcillin/clavulanic acid. the wound was debrided twice, and later a skin flap was ...19989884842
[kluyvera cryocrescens: a positive urine culture in a young girl with persistent proteinuria].kluyvera genus usually shows two kinds of species: k. ascorbata and k. cryocrescens, dna hybridization let us to differentiate a third group: kluyvera species 3. its diagnosis is quite uncommon and its taxonomy have been recently clarified. we report here a ten years female record with a chronic proteinuria and a positive urine-culture for k. cryocrescens. axetil cefuroxime treatment was absolutely succesful. kluyvera infections are difficult on the whole to joint with some specific clinical fea ...199910464962
the use of chromogenic reference substrates for the kinetic analysis of penicillin acylases.determination of kinetic parameters of penicillin acylases for phenylacetylated compounds is complicated due to the low k(m) values for these substrates, the lack of a spectroscopic signal, and the strong product inhibition by phenylacetic acid. to overcome these difficulties, a spectrophotometric method was developed, with which kinetic parameters could be determined by measuring the effects on the hydrolysis of the chromogenic reference substrate 2-nitro-5-[(phenylacetyl)amino]benzoic acid (ni ...199910542108
[bacteremia by kluyvera ascorbata in a patient with neutropenia and fever]. 200010721566
plant growth-promoting bacteria that decrease heavy metal toxicity in plants.kluyvera ascorbata sud165 and a siderophore-overproducing mutant of this bacterium, k. ascorbata sud165/26, were used to inoculate tomato, canola, and indian mustard seeds which were then grown in soil for 25-42 days in the presence of either nickel, lead, or zinc. the parameters that were monitored included plant wet and dry weight, protein and chlorophyll content in the plant leaves, and concentration of heavy metal in the plant roots and shoots. as indicated by a decrease in the measured valu ...200010749537
outbreak of nosocomial infections due to extended-spectrum beta-lactamase-producing strains of enteric group 137, a new member of the family enterobacteriaceae closely related to citrobacter farmeri and citrobacter amalonaticus.a member of the enterobacteriaceae initially identified as kluyvera cryocrescens by the microscan gram-negative combo 13 panel caused an outbreak of nosocomial infections in four patients (pneumonia, n = 2; urinary tract infection, n = 1; wound infection, n = 1) and urinary tract colonization in one patient. when the strains were tested by the enteric reference laboratory of the centers for disease control and prevention, biochemical results were most compatible with yersinia intermedia, kluyver ...200011060050
nucleotide sequence and characterization of a novel cefotaxime-hydrolyzing beta-lactamase (ctx-m-10) isolated in spain.a cefotaxime-resistant, ceftazidime-susceptible escherichia coli isolate was obtained from a patient with sepsis in 1997, from which a beta-lactamase with a pi of 8.1 was cloned. cephaloridine and cefotaxime relative hydrolysis rates were 167 and 81, respectively (penicillin g rate = 100), whereas ceftazidime hydrolysis was not detected. the nucleotide sequence revealed a bla gene related to that coding for ctx-m-3. despite 21 nucleotide substitutions, only 2 determined amino acid changes (ala27 ...200111158766
[kluyvera ascorbata. case report of a patient with crohn's disease].for the not frequent, we contributed a new case of infection urinary produced by the i generate kluyvera. we make a bibliographical review, clinical expression of the same and we insisted in a series of peculiarities, you like the appearance give because of the treatment pharmacologic and their intestinals.200111284373
biological activity and colonization pattern of the bioluminescence-labeled plant growth-promoting bacterium kluyvera ascorbata sud165/26.kluyvera ascorbata sud165/26 is a spontaneous siderophore-overproducing mutant of k. ascorbata sud165, which was previously isolated from nickel-contaminated soil and shown to significantly enhance plant growth in soil contaminated with high levels of heavy metals. to develop a better understanding of the functioning of k. ascorbata sud165/26 in the environment, and to trace its distribution in the rhizosphere, isolates of this bacterium were labeled with either green fluorescent protein or luci ...200111295452
fluorogenic assay for penicillin g acylase activity.a simple, highly sensitive, and rapid assay for high-throughput screening of penicillin g acylase-producing bacteria is presented. the method is based on the specific release of fluorescent 7-amino-4-methyl-coumarin through cleavage of phenylacetyl-4-methyl-coumaryl-7-amide by penicillin g acylase. the present method is suitable for screening pure enzymes as well as various penicillin g acylases like those from escherichia coli, proteus rettgeri, and kluyvera citrophila in cell extracts. in addi ...200111355855
further studies on rpos in enterobacteria: identification of rpos in enterobacter cloacae and kluyvera cryocrescens.rpos, the alternative sigma factor sigma(s), is important for bacterial survival under extreme conditions. many enterobacteria are opportunistic human pathogens and their ability to survive in a changing environment could be an essential step for their virulence. to determine the presence of this gene in enteric bacteria, an escherichia coli rpos probe was constructed and used to detect the presence of this gene in different species. a gene homologous to rpos was found in citrobacter amalonaticu ...200111491080
infections caused by kluyvera species in humans.kluyvera is a relatively newly described genus in the family enterobacteriaceae that infrequently causes infections in humans. the organism has been isolated from various clinical specimens, but its significance has not been clearly established. in fact, it has been regarded alternatively as saprophytic, opportunistic, or pathogenic. since the redefinition of this genus in 1981, case reports of diverse clinical infections occurring under various host conditions have been published. here we prese ...200111528588
emended description of buttiauxella agrestis with recognition of six new species of buttiauxella and two new species of kluyvera: buttiauxella ferragutiae sp. nov., buttiauxella gaviniae sp. nov., buttiauxella brennerae sp. nov., buttiauxella izardii sp. nov., buttiauxella noackiae sp. nov., buttiauxella warmboldiae sp. nov., kluyvera cochleae sp. nov., and kluyvera georgiana sp. nov.a total of 219 strains belonging to the genera buttiauxella and kluyvera were studied; 171 of these strains were isolated from mollusks, mainly snails and slugs, obtained from around the world. on the basis of dna-dna hybridization data, the strains were grouped into 11 genomospecies. a total of 44 phenotypic characters were used to differentiate the genera buttiauxella and kluyvera at the genus level and to identify genomospecies. there were significantly higher phenotypic probability distances ...199611534554
intervening sequences in rrl genes and fragmentation of 23s rrna in genera of the family enterobacteriaceae.intervening sequences (ivss) in the rrl genes for 23s rrna are transcribed but later removed by rnase iii without religation during rna processing, leading to fragmented rrna. we examined about 240 strains of the family enterobacteriaceae for presence of ivss using pcr. no ivss were detected in strains belonging to escherichia, shigella, enterobacter, erwinia, ewingella, hafnia, kluyvera, morganella, pantoea, or serratia. previously unreported ivss were detected in klebsiella oxytoca, citrobacte ...200111544246
characterization of a chromosomally encoded extended-spectrum class a beta-lactamase from kluyvera cryocrescens.a chromosomally located beta-lactamase gene, cloned and expressed in escherichia coli from a reference strain of the enterobacterial species kluyvera cryocrescens, encoded a clavulanic acid-inhibited ambler class a enzyme, kluc-1, with a pi value of 7.4. kluc-1 shared 86% amino acid identity with a subgroup of plasmid-mediated ctx-m-type extended-spectrum beta-lactamases (ctx-m-1, -3, -10, -11, and -12), the most closely related enzymes, and 77% amino acid identity with klua-1 from kluyvera asco ...200111709346
acute cholecystitis and bacteremia caused by kluyvera ascorbata in a cirrhotic patient. 199811864301
nosocomial outbreak of kluyvera cryocrescens bacteremia. 200211893149
diversity of ctx-m beta-lactamases and their promoter regions from enterobacteriaceae isolated in three parisian hospitals.nine clinical isolates of enterobacteriaceae (six escherichia coli and three proteus mirabilis) isolated in three parisian hospitals between 1989 and 2000 showed a particular extended-spectrum cephalosporin-resistance profile characterized by resistance to cefotaxime and aztreonam but not to ceftazidime. ctx-m-1, ctx-m-2, ctx-m-9, ctx-m-14 and two novel plasmid-mediated ctx-m beta-lactamases (ctx-m-20, and ctx-m-21) were identified by polymerase chain reaction and isoelectric focusing (pi>8) and ...200212007800
novel class 1 integron (ins21) carrying blactx-m-2 in salmonella enterica serovar infantis.the genetic organization of the region coding for ctx-m-2 in salmonella enterica serovar infantis was determined by pcr mapping. this gene seems to have been mobilized from the kluyvera ascorbata chromosome to a complex suli-type integron, similar to in6 and in7.200212069984
blactx-m-2 is located in an unusual class 1 integron (in35) which includes orf513.examination of the bla(ctx-m-2) gene in plasmid pmar-12 by sequencing and pcr analysis revealed that the bla gene and the surrounding dna, which is closely related (99% homology) to the kluyvera ascorbata chromosomal dna that contains the bla(klua-1) gene, are located in a complex sul1-type integron, termed in35, that includes orf513. it is possible that bla(ctx-m-2) was acquired by plasmid pmar-12 through an uncharacterized recombinational event in which orf513 could be involved.200212069995
beta-lactamases of kluyvera ascorbata, probable progenitors of some plasmid-encoded ctx-m types.kluyvera ascorbata produces a beta-lactamase that results in an atypical susceptibility pattern, including low-level resistance to penicillins, cephalothin, and cefuroxime, but this resistance is reversed by clavulanate. ten nucleotide sequences of the corresponding gene, bla(klua), were obtained and were found to have minor variations (96 to 100%). otherwise, bla(klua) was found to be similar (95 to 100%) to some plasmid-encoded ctx-m-type beta-lactamases. finally, mobilization of bla(klua) on ...200212183268
[acute cholecystitis due to kluyvera ascorbata]. 200212237007
identification of a chromosome-borne expanded-spectrum class a beta-lactamase from erwinia persicina.from whole-cell dna of an enterobacterial erwinia persicina reference strain that displayed a penicillinase-related antibiotic-resistant phenotype, a beta-lactamase gene was cloned and expressed in escherichia coli. it encoded a clavulanic-acid-inhibited ambler class a beta-lactamase, erp-1, with a pi value of 8.1 and a relative molecular mass of ca. 28 kda. erp-1 shared 45 to 50% amino acid identity with the most closely related enzymes, the chromosomally encoded enzymes from citrobacter koseri ...200212384342
chromosome-encoded ambler class a beta-lactamase of kluyvera georgiana, a probable progenitor of a subgroup of ctx-m extended-spectrum beta-lactamases.a chromosome-encoded beta-lactamase gene, cloned and expressed in escherichia coli from kluyvera georgiana reference strain cuetm 4246-74 (dsm 9408), encoded the extended-spectrum beta-lactamase klug-1, which shared 99% amino acid identity with the plasmid-mediated beta-lactamase ctx-m-8. this work provides further evidence that kluyvera spp. may be the progenitor(s) of ctx-m-type beta-lactamases.200212435721
identification of tem-10 beta-lactamase in a kluyvera sp. and other enterobacteriaceae at a portuguese hospital. 200212435722
occurrence and phenotypic characteristics of extended-spectrum beta-lactamases among members of the family enterobacteriaceae at the tel-aviv medical center (israel) and evaluation of diagnostic tests.we assessed the prevalence and phenotypic characteristics of extended-spectrum beta-lactamase (esbl) producers among cefuroxime-resistant (cxm-r) (mic > or = 32 micro g/ml) members of the family enterobacteriaceae in our institution. the 438 cxm-r clinical isolates obtained from nonurine sources among inpatients were screened. esbl production was confirmed by disk diffusion assay using cefpodoxime (cpd), cefotaxime (ctx), and ceftazidime (ctz) with and without clavulanate (clav). a difference of ...200312517841
study of the bacterial load in a gelatine production process focussed on bacillus and related endosporeforming genera.gelatine is an animal protein with many industrial applications. previous studies pointed out that endosporeforming bacteria, belonging to the genus bacillus or related genera, might contaminate and survive the production process of gelatine, leading to products of low quality and safety. the aim of this study is to determine the bacterial diversity of contaminants isolated from a gelatine production chain with emphasis on aerobic endosporeforming bacteria. contaminants were isolated from sample ...200212583722
central venous catheter infection in a child: case report and review of kluyvera infection in children.kluyvera is an opportunistic pathogen that can occur in immunosuppressed as well as immunocompetent hosts. we report a case of kluyvera species infection involving a central venous catheter, and we review the literature on kluyvera infections in children. our case demonstrates that removal of the central venous catheter was necessary to eradicate the infection and hasten the resolution of refractory neutropenia. the spectrum of disease due to kluyvera infection in children includes central venou ...200312630654
polymorphism in the yclc-rpos region of enterobacteria.the nucleotide sequence downstream from the rpos gene in enterobacter cloacae and kluyvera cryocrescens contains the slya-pad1-yclc genes. the dna sequence of enterobacter cloacae cetc960 shows a 2.6-kb insertion of unknown origin between rpos and slya. this 2.6-kb sequence has also been detected in species of salmonella and in pseudomonas aeruginosa, but not in the same location. this insertion has been detected in all the enterobacter cloacae clinical strains studied although the size of the r ...200312732965
improving the specific synthetic activity of a penicillin g acylase using dna family shuffling.penicillin g acylas (pga) of providencia rettgeri (atcc 25599) was evolved using a modified dna family shuffling method. the identity of pga genes from escherichia coli, kluyvera citrophila and providencia rettgeri ranges from 62.5% to 96.9%. the pga genes from above three species were recombined and shuffled to create interspecies pga gene fusion libraries. by substituting assembled chimaeras for corresponding region of petppga, different recombinants were constructed and expressed in e. coli j ...200312796820
moraxella and kluyvera peritonitis in a capd patient with human immunodeficiency virus. 200314703211
the incidence of oral gram-negative bacteria in patients with parkinson's disease.background: parkinson's disease is a common neurodegenerative disorder that affects an increasing number of older people every year. dysphagia is not only a common feature, but one that results in poor nutrition and an increased risk of bronchopneumonia. previous work has suggested that the oral flora is altered in patients with oral pathology. methods: fifty patients were assessed to quantify the incidence of oral gram-negative bacteria. results: sixteen of the patients with parkinson's disease ...200314962700
cefotaximases (ctx-m-ases), an expanding family of extended-spectrum beta-lactamases.among the extended-spectrum beta-lactamases, the cefotaximases (ctx-m-ases) constitute a rapidly growing cluster of enzymes that have disseminated geographically. the ctx-m-ases, which hydrolyze cefotaxime efficiently, are mostly encoded by transferable plasmids, and the enzymes have been found predominantly in enterobacteriaceae, most prevalently in escherichia coli, salmonella typhimurium, klebsiella pneumoniae, and proteus mirabilis. isolates of vibrio cholerae, acinetobacter baumannii, and a ...200415105882
cloning, overexpression, and characterization of a novel thermostable penicillin g acylase from achromobacter xylosoxidans: probing the molecular basis for its high thermostability.the gene encoding a novel penicillin g acylase (pga), designated pgaw, was cloned from achromobacter xylosoxidans and overexpressed in escherichia coli. the pgaw gene contains an open reading frame of 2586 nucleotides. the deduced protein sequence encoded by pgaw has about 50% amino acid identity to several well-characterized pgas, including those of providencia rettgeri, kluyvera cryocrescens, and escherichia coli. biochemical studies showed that the optimal temperature for this novel pga (pga6 ...200415128530
fatal emphysematous gastritis in a 2-year-old child with chronic renal failure. 200415383939
expression, purification, and characterization of his-tagged penicillin g acylase from kluyvera citrophila in escherichia coli.the dna fragment encoding kluyvera citrophila penicillin g acylase (kcpga) was amplified and cloned into the vector pet28b to obtain a c-terminus his-tagged fusion expression plasmid. the fusion protein kcpga was successfully overexpressed in escherichia coli bl21(de3). the optimal induction concentration of isopropylthio-beta-d-galactoside (iptg) was found to be 5 microm. the fusion protein was purified in a single step by ni-ida affinity chromatograph to a specific activity of 35.3u/mg protein ...200415477078
identification of enterobacteriaceae from washed and unwashed commercial shell evaluate the effect of processing on the safety and quality of retail shell eggs, a storage study was conducted with unwashed and commercially washed eggs. this work demonstrated that commercial processing decreased microbial contamination of eggshells. to know which species persisted during storage on washed or unwashed eggs, enterobacteriaceae isolates were selected and identified biochemically. for each of three replications, shell eggs were purchased from a commercial processing plant, tr ...200415553650
chromosome-encoded ctx-m-3 from kluyvera ascorbata: a possible origin of plasmid-borne ctx-m-1-derived cefotaximases.a gene identical to plasmid-borne bla(ctx-m-3) is present in the chromosome of one kluyvera ascorbata strain. it is associated with a structure including an inverted repeat right and an open reading frame 477-like gene probably involved in the mobilization of bla(ctx-m-3). two other k. ascorbata strains rendered the previously described bla(klua-9) gene.200415561876
evidence for the involvement of arginyl residue at the active site of penicillin g acylase from kluyvera citrophila.penicillin g acylase (pga) is used for the commercial production of semi-synthetic penicillins. it hydrolyses the amide bond in penicillin producing 6-aminopenicillanic acid and phenylacetate. 6-aminopenicillanic acid, having the beta-lactam nucleus, is the parent compound for all semi-synthetic penicillins. penicillin g acylase from kluyvera citrophila was purified and chemically modified to identify the role of arginine in catalysis. modification with 20 mm phenylglyoxal and 50 mm 2,3-butanedi ...200415604805
phylogenetic relationships of the genus kluyvera: transfer of enterobacter intermedius izard et al. 1980 to the genus kluyvera as kluyvera intermedia comb. nov. and reclassification of kluyvera cochleae as a later synonym of k. order to assess the relationship between the genus kluyvera and other members of the family enterobacteriaceae, the 16s rrna genes of type strains of the recognized kluyvera species, kluyvera georgiana, kluyvera cochleae, kluyvera ascorbata and kluyvera cryocrescens, were sequenced. a comparative phylogenetic analysis based on these 16s rrna gene sequences and those available for strains belonging to several genera of the family enterobacteriaceae showed that members of the genus kluyvera for ...200515653915
soft tissue infection caused by kluyvera species. 200515665722
supercooling ability in two populations of the land snail helix pomatia (gastropoda: helicidae) and ice-nucleating activity of gut bacteria.the land snail helix pomatia (gastropoda: helicidae) is widely distributed in northern and central europe where it may experience subzero temperatures during winter months. its supercooling ability was studied in two populations of h. pomatia. one population originated from southern sweden (gotaland) and the other from central france (auvergne). in the experimental design, they were acclimated, over 2 weeks, to artificial winter conditions (hibernation, t=5 degrees c). the swedish snails showed ...200415710369
clinically significant kluyvera infections: a report of seven determine the clinical significance of kluyvera isolates at our institution, we retrospectively analyzed clinical microbiology data from january 1999 to september 2003. we identified 11 isolates classified as kluyvera ascorbata, 7 of which were considered clinically significant pathogens: 3 cases represented urinary tract infections; 2, bacteremia; 1, a soft tissue infection of the finger; and 1, acute appendicitis with a subsequent intra-abdominal abscess. the age distribution of patients wa ...200515716228
description of in116, the first blactx-m-2-containing complex class 1 integron found in morganella morganii isolates from buenos aires, argentina.we analysed the architecture and probable origin of a class 1 integron from cefotaxime-resistant morganella morganii isolates.200515743901
[respiratory infection by kluyvera sp. cause or consequence?]. 200515777126
identification of a progenitor of the ctx-m-9 group of extended-spectrum beta-lactamases from kluyvera georgiana isolated in guyana.chromosomal beta-lactamase genes (bla(kluy)) from six kluyvera georgiana strains isolated in guyana were cloned and expressed in escherichia coli. kluy-1 exhibited 100% amino acid identity with the extended-spectrum beta-lactamase ctx-m-14. we also show that a 2.7-kb kluyvera chromosomal region exhibits 99% nucleotide identity to a portion of in60 that includes bla(ctx-m-9).200515855541
natural antimicrobial susceptibility patterns of kluyvera ascorbata and kluyvera cryocrescens strains and review of the clinical efficacy of antimicrobial agents used for the treatment of kluyvera infections.the natural susceptibility of 58 k. ascorbata and 24 k. cryocrescens strains to 71 antimicrobial agents was investigated. mic values were determined with a microdilution procedure in cation-adjusted mueller hinton broth (for all strains) and isosensitest broth (for some strains). both species were naturally sensitive or of intermediate susceptibility to tetracyclines, aminoglycosides, quinolones, antifolates, chloramphenicol, nitrofurantoin, fosfomycin, aminopenicillins plus beta-lactamase inhib ...200515920899
kluyvera urinary tract infection: case report and review of the literature.we report the occurrence of kluyvera ascorbata urinary tact infection, presenting as acute pyelonephritis, in a 19-month-old girl without underlying uropathy. quick response to antibiotic therapy was obtained, and there was no residual renal parenchymal damage. we review the literature of infections with this very uncommon organism with particular emphasis on pediatric urinary tract infections.200515933577
monitoring of microbial community structure and succession in the biohydrogen production reactor by denaturing gradient gel electrophoresis (dgge).to study the structure of microbial communities in the biological hydrogen production reactor and determine the ecological function of hydrogen producing bacteria, anaerobic sludge was obtained from the continuous stirred tank reactor (cstr) in different periods of time, and the diversity and dynamics of microbial communities were investigated by denaturing gradient gel electrophoresis (dgge). the results of dgge demonstrated that an obvious shift of microbial population happened from the beginn ...200515986888
ctx-m: changing the face of esbls in the uk.the uk has experienced a sudden rise in extended-spectrum beta-lactamase (esbl) rates, largely due to the appearance and spread of escherichia coli producing ctx-m-15 type beta-lactamase. the british society for antimicrobial chemotherapy organized two update meetings during 2004 to report and discuss the recognition, clinical diagnosis, treatment and control of bacteria producing these beta-lactamases. this paper reports the data and reviews made by contributors to the conferences. the historic ...200516006451
urinary tract infection caused by kluyvera ascorbata in an immunocompromised patient: case report and review.we describe an immunocompromised patient, aged 78 y, with urinary tract infection caused by kluyvera ascorbata. complete recovery was achieved on antibiotic therapy with ceftriaxone. review of the literature clearly indicates that k. ascorbata is a potentially dangerous pathogen either in the immunocompetent or in the immunocompromised host. k. ascorbata, and in general kluyvera species, deserve prompt identification in order to determine antimicrobial susceptibility pattern and a correct and ag ...200516051578
expression and purification of penicillin g acylase enzymes from four different micro-organisms, and a comparative evaluation of their synthesis/hydrolysis ratios for cephalexin.several genes for the enzyme penicillin g acylase, as isolated from four different micro-organisms (alcaligenes facaelis, escherichia coli, kluyvera cryocrescens or providencia rettgeri) were modified at their carboxy-termini to include his-tag fusions, then were expressed from the plasmid pet-24a(+) in e. coli jm109(de3) cells. all fusion proteins were next purified to homogeneity in a single step by agar-based co-ida chromatography, and were then evaluated as catalysts for the synthesis of cep ...200616139515
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