| survival of coliforms and bacterial pathogens within protozoa during chlorination. | the susceptibility of coliform bacteria and bacterial pathogens to free chlorine residuals was determined before and after incubation with amoebae and ciliate protozoa. viability of bacteria was quantified to determine their resistance to free chlorine residuals when ingested by laboratory strains of acanthamoeba castellanii and tetrahymena pyriformis. cocultures of bacteria and protozoa were incubated to facilitate ingestion of the bacteria and then were chlorinated, neutralized, and sonicated ... | 1988 | 3223766 |
| first isolation of legionella gormanii from human disease. | legionella gormanii, previously isolated only from the environment, was grown from the bronchial brush specimen of a patient with pneumonia. the organism was characterized by serologic, biochemical, and dna hybridization studies. | 1988 | 3278000 |
| agglutinating antibody titers to members of the family legionellaceae in cystic fibrosis patients as a result of cross-reacting antibodies to pseudomonas aeruginosa. | the objective of this study was to evaluate the prevalence and significance of antibody titers to organisms in the family legionellaceae in 128 serum samples collected from cystic fibrosis patients at routine examinations. antibody titers were determined for 10 antigenic types of legionellaceae; legionella pneumophila serogroups 1 to 6, fluoribacter (legionella) bozemanae, fluoribacter (legionella) dumoffii, fluoribacter (legionella) gormanii, and tatlockia (legionella) micdadei. the method of a ... | 1984 | 6206086 |
| determination of catalase, peroxidase, and superoxide dismutase within the genus legionella. | we examined 40 strains of legionella for reduced-oxygen scavenging enzymes. using a simple reaction chamber with a swinney filter for the beers and sizer assay, we determined the catalase activity of live cells grown on buffered charcoal-yeast extract agar. for 29 strains of legionella pneumophila, the apparent first-order rate constants for catalase ranged from 0.000 to 0.005. similarly, low values ranging from 0.001 to 0.005 were observed for legionella wadsworthii, legionella oakridgensis, an ... | 1984 | 6490828 |
| clinical laboratory differentiation of legionellaceae family members with pigment production and fluorescence on media supplemented with aromatic substrates. | a systematic study of pigment production (browning) and fluorescence (extracellular yellow-green and intracellular blue-white) by nine legionellaceae species was performed. a total of 56 strains representing tatlockia micdadei (pittsburgh pneumonia agent), legionella pneumophila, legionella jordanis, legionella longbeachae, legionella oakridgensis, legionella wadsworthii, fluoribacter bozemanae, fluoribacter gormanii, and fluoribacter dumoffii could be separated on media supplemented with tyrosi ... | 1984 | 6547453 |
| electrophoretic characterization of soluble protein extracts of legionella pneumophila and other members of the family legionellaceae. | the soluble peptides of strains of legionella pneumophila, tatlockia micdadei, fluoribacter bozemanae, fluoribacter dumoffii, and fluoribacter gormanii were studied by polyacrylamide gel electrophoresis. characteristic patterns were seen for legionella and tatlockia strains, whereas the patterns for the fluoribacter strains were variable as would be expected for this genetically heterogeneous group. grouping by peptide pattern was consistent with proposed taxons based on dna-dna homology. by usi ... | 1983 | 6874904 |
| legionella micdadei (pittsburgh pneumonia agent): direct fluoresent-antibody examination of infected human lung tissue and characterization of clinical isolates. | legionella micdadei (pittsburgh pneumonia agent) was identified by direct fluorescent-antibody (dfa) examination of lung tissue in six of seven persons diagnosed previously as having l. micdadei pneumonia only by histopathology and in four persons who also had positive cultures of the organism. no cross-reactions occurred with monospecific dfa conjugates prepared against legionella pneumophila serogroups 1 to 6, legionella bozemanii, legionella dumoffii, and legionella gormanii. one person had l ... | 1981 | 7014621 |
| detection of cell-associated or soluble antigens of legionella pneumophila serogroups 1 to 6, legionella bozemanii, legionella dumoffii, legionella gormanii, and legionella micdadei by staphylococcal coagglutination tests. | current methods used for the detection of whole-cell isolates of legionella or for the detection of legionella soluble antigens are technically impractical for many clinical laboratories. the purpose of this study was to explore practical alternatives. the results showed that whole cell isolates of legionella pneumophila serogroups 1 to 6, legionella bozemanii, legionella dumoffii, legionella gormanii, and legionella micdadei were identified specifically by a simple slide agglutination test or s ... | 1981 | 7287888 |
| susceptibility of pittsburgh pneumonia agent (legionella micdadei) and other newly recognized members of the genus legionella to nineteen antimicrobial agents. | the susceptibilities of 11 strains representing the five recognized species of legionella were determined by agar dilution testing on buffered charcoal-yeast extract agar. all of the legionellae tested were susceptible to rifampin, erythromycin, rosaramycin, chloramphenicol, and the aminoglycosides and were resistant to clindamycin and vancomycin. susceptibilities to penicillins and cephalosporins were variable. legionella micdadei, legionella bozemanii, and legionella gormanii were susceptible ... | 1981 | 7325645 |
| rapid detection and evaluation of clinical characteristics of emerging multiple-drug-resistant gram-negative rods carrying the metallo-beta-lactamase gene blaimp. | gram-negative rods (gnr) carrying the transferable carbapenem resistance gene blaimp, including pseudomonas aeruginosa and serratia marcescens, have been isolated from more than 20 hospitals in japan. although the emergence of such multiple-drug-resistant bacteria is of utmost clinical concern, little information in regard to the distribution of blaimp-positive gnr in hospitals and the clinical characteristics of infected patients is available. to address this, a system for the rapid detection o ... | 1998 | 9687398 |
| characterization of vim-2, a carbapenem-hydrolyzing metallo-beta-lactamase and its plasmid- and integron-borne gene from a pseudomonas aeruginosa clinical isolate in france. | pseudomonas aeruginosa col-1 was identified in a blood culture of a 39-year-old-woman treated with imipenem in marseilles, france, in 1996. this strain was resistant to beta-lactams, including ureidopenicillins, ticarcillin-clavulanic acid, cefepime, ceftazidime, imipenem, and meropenem, but remained susceptible to the monobactam aztreonam. the carbapenem-hydrolyzing beta-lactamase gene of p. aeruginosa col-1 was cloned, sequenced, and expressed in escherichia coli dh10b. the deduced 266-amino-a ... | 2000 | 10722487 |
| metallo-beta-lactamase producers in environmental microbiota: new molecular class b enzyme in janthinobacterium lividum. | eleven environmental samples from different sources were screened for the presence of metallo-beta-lactamase-producing bacteria by using a selective enrichment medium containing a carbapenem antibiotic and subsequently testing each isolate for production of edta-inhibitable carbapenemase activity. a total of 15 metallo-beta-lactamase-producing isolates, including 10 stenotrophomonas maltophilia isolates, 3 chryseobacterium spp., one aeromonas hydrophila isolate, and one janthinobacterium lividum ... | 2001 | 11181369 |
| biochemical characterization of the fez-1 metallo-beta-lactamase of legionella gormanii atcc 33297t produced in escherichia coli. | the bla(fez-1) gene coding for the metallo-beta-lactamase of legionella (fluoribacter) gormanii atcc 33297t was overexpressed via a t7 expression system in escherichia coli bl21(de3)(plyss). the product was purified to homogeneity in two steps with a yield of 53%. the fez-1 metallo-beta-lactamase exhibited a broad-spectrum activity profile, with a preference for cephalosporins such as cephalothin, cefuroxime, and cefotaxime. monobactams were not hydrolyzed. the beta-lactamase was inhibited by me ... | 2001 | 11257043 |
| population genetic structure of legionella pneumophila inferred from rna polymerase gene (rpob) and dota gene (dota) sequences. | the population structure of legionella pneumophila was studied by using partial rna polymerase gene (rpob) and dota gene (dota) sequences. trees inferred from rpob sequences showed that two subspecies of l. pneumophila, legionella pneumophila subsp. pneumophila and legionella pneumophila subsp. fraseri, were clearly separated genetically. in both rpob and dota trees, 79 korean isolates used in this study constituted six clonal populations, four of which (designated subgroups p-i to p-iv) were id ... | 2002 | 11914343 |
| use of the caulobacter crescentus genome sequence to develop a method for systematic genetic mapping. | the functional analysis of sequenced genomes will be facilitated by the development of tools for the rapid mapping of mutations. we have developed a systematic approach to genetic mapping in caulobacter crescentus that is based on bacteriophage-mediated transduction of strategically placed antibiotic resistance markers. the genomic dna sequence was used to identify sites distributed evenly around the chromosome at which plasmids could be nondisruptively integrated. dna fragments from these sites ... | 2002 | 11914347 |
| overproduction and biochemical characterization of the chryseobacterium meningosepticum blab metallo-beta-lactamase. | the blab metallo-beta-lactamase of chryseobacterium meningosepticum ccug4310 was overproduced in escherichia coli by means of a t7 promoter-based expression system. the overproducing system, scaled up in a 15-liter fermentor, yielded approximately 10 mg of blab protein per liter, mostly released in the culture supernatant. the enzyme was purified by two ion-exchange chromatographic steps with an overall yield of 66%. analysis of the kinetic parameters revealed efficient activities (k(cat)/k(m) r ... | 2002 | 12019109 |
| genetic and biochemical characterization of cgb-1, an ambler class b carbapenem-hydrolyzing beta-lactamase from chryseobacterium gleum. | chryseobacterium gleum (previously included in the flavobacterium iib species) is a gram-negative aerobe that is a source of nosocomial infections. an ambler class b beta-lactamase gene was cloned and expressed in escherichia coli from reference strain c. gleum cip 103039 that had reduced susceptibility to expanded-spectrum cephalosporins and carbapenems. the purified beta-lactamase, cgb-1, with a pi value of 8.6 and a determined relative molecular mass of ca. 26 kda, hydrolyzed penicillins; nar ... | 2002 | 12183230 |
| ebr-1, a novel ambler subclass b1 beta-lactamase from empedobacter brevis. | empedobacter brevis (formerly designated flavobacterium breve) is a gram-negative aerobe involved in nosocomial infections. the ambler class b beta-lactamase gene bla(ebr-1) was cloned and expressed in escherichia coli from e. brevis clinical strain ass-1, which had reduced susceptibility to expanded-spectrum cephalosporins and carbapenems. purified beta-lactamase ebr-1 hydrolyzed penicillins, cephalosporins, and carbapenems efficiently but not aztreonam. kinetic parameters of ebr-1 were similar ... | 2002 | 12234848 |
| chromosome-encoded beta-lactamases tus-1 and mus-1 from myroides odoratus and myroides odoratimimus (formerly flavobacterium odoratum), new members of the lineage of molecular subclass b1 metalloenzymes. | myroides odoratus and myroides odoratimimus (formerly designated in a single species as flavobacterium odoratum) are gram-negative aerobes and sources of nosocomial infections in humans. they have variable susceptibility to beta-lactams and a decreased susceptibility to carbapenems. using genomic dnas of m. odoratus cip 103105 and m. odoratimimus cip 103073 reference strains, shotgun cloning of beta-lactamase genes was performed, followed by protein expression in escherichia coli. the deduced am ... | 2002 | 12384365 |
| biochemical characterization of the acquired metallo-beta-lactamase spm-1 from pseudomonas aeruginosa. | spm-1 is a new metallo-beta-lactamase recently identified in pseudomonas aeruginosa strain 48-1997a, isolated in sao paulo, brazil. kinetic analysis demonstrated that spm-1 has a broad hydrolytic profile across a wide range of beta-lactam antibiotics. considerable variation was observed within the penicillin, cephalosporin, and carbapenem subfamilies; however, on the whole, spm-1 appears to preferentially hydrolyze cephalosporins. the highest k(cat/)k(m) ratios (in micromolar per second) overall ... | 2003 | 12543663 |
| neonatal sudden death due to legionella pneumonia associated with water birth in a domestic spa bath. | we report the first case of neonatal legionnaires' disease associated with water birth in a spa bath at home. legionella pneumophila serogroup 6 was detected from postmortem lung tissue. | 2003 | 12734286 |
| nmca carbapenem-hydrolyzing enzyme in enterobacter cloacae in north america. | an imipenem-resistant enterobacter cloacae isolate was recovered from the blood of a patient with a hematologic malignancy. analytical isoelectric focusing, inhibitor studies, hydrolysis, induction assays, and molecular sequencing methods confirmed the presence of a nmca carbapenem-hydrolyzing enzyme. this first report of nmca detected in north america warrants further investigation into its distribution and clinical impact. | 2003 | 12967501 |
| characterization of the alternative sigma factor sigma54 and the transcriptional regulator fleq of legionella pneumophila, which are both involved in the regulation cascade of flagellar gene expression. | we cloned and analyzed legionella pneumophila corby homologs of rpon (encoding sigma(54)) and fleq (encoding sigma(54) activator protein). two other genes (fler and pilr) whose products have a sigma(54) interaction domain were identified in the genome sequence of l. pneumophila. an rpon mutant strain was nonflagellated and expressed very small amounts of the flaa (flagellin) protein. like the rpon mutant, the fleq mutant strain of l. pneumophila was also nonflagellated and expressed only small a ... | 2004 | 15090493 |
| metallo-beta-lactamases: the quiet before the storm? | the ascendancy of metallo-beta-lactamases within the clinical sector, while not ubiquitous, has nonetheless been dramatic; some reports indicate that nearly 30% of imipenem-resistant pseudomonas aeruginosa strains possess a metallo-beta-lactamase. acquisition of a metallo-beta-lactamase gene will invariably mediate broad-spectrum beta-lactam resistance in p. aeruginosa, but the level of in vitro resistance in acinetobacter spp. and enterobacteriaceae is less dependable. their clinical significan ... | 2005 | 15831827 |
| development and evaluation of chlamylege, a new commercial test allowing simultaneous detection and identification of legionella, chlamydophila pneumoniae, and mycoplasma pneumoniae in clinical respiratory specimens by multiplex pcr. | this study describes the development and evaluation of a new commercial test, chlamylege (argene inc.), which allows the simultaneous detection in respiratory samples of chlamydophila pneumoniae, mycoplasma pneumoniae, and most legionella species, as well as pcr inhibitors, by using a multiplex pcr and microplate hybridization. the sensitivities of chlamylege were 1 x 10(-3) ifu, 5 x 10(-2) color-changing units, and 1 cfu per reaction tube for c. pneumoniae, m. pneumoniae, and legionella pneumop ... | 2005 | 16000443 |
| legionella confirmation using real-time pcr and syto9 is an alternative to current methodology. | the currently accepted culture techniques for the detection of legionella spp. in water samples (as/nzs 3896:1998 and iso 11731 standard methods) are slow and laborious, requiring from 7 to 14 days for a result. we describe a fully validated rapid confirmation technique that uses real-time pcr incorporating the intercalating dye syto9 for the direct identification of primary cultures, significantly decreasing turnaround time and allowing faster remedial action to be taken by the industry. | 2005 | 16332896 |
| identification of legionella pneumophila-specific genes by genomic subtractive hybridization with legionella micdadei and identification of lpne, a gene required for efficient host cell entry. | legionella pneumophila is a ubiquitous environmental organism and a facultative intracellular pathogen of humans. to identify genes that may contribute to the virulence of l. pneumophila, we performed genomic subtractive hybridization between l. pneumophila serogroup 1 strain 02/41 and l. micdadei strain 02/42. a total of 144 l. pneumophila-specific clones were sequenced, revealing 151 genes that were absent in l. micdadei strain 02/42. low-stringency southern hybridization was used to determine ... | 2006 | 16495539 |
| compensatory functions of two alkyl hydroperoxide reductases in the oxidative defense system of legionella pneumophila. | legionella pneumophila expresses two catalase-peroxidase enzymes that exhibit strong peroxidatic but weak catalatic activities, suggesting that other enzymes participate in decomposition of hydrogen peroxide (h2o2). comparative genomics revealed that l. pneumophila and its close relative coxiella burnetii each contain two peroxide-scavenging alkyl hydroperoxide reductase (ahpc) systems: ahpc1, which is similar to the helicobacter pylori ahpc system, and ahpc2 ahpd (ahpc2d), which is similar to t ... | 2006 | 16923890 |
| the activity of the dinuclear cobalt-beta-lactamase from bacillus cereus in catalysing the hydrolysis of beta-lactams. | metallo-beta-lactamases are native zinc enzymes that catalyse the hydrolysis of beta-lactam antibiotics, but are also able to function with cobalt(ii) and require one or two metal-ions for catalytic activity. the hydrolysis of cefoxitin, cephaloridine and benzylpenicillin catalysed by cobcii (cobalt-substituted beta-lactamase from bacillus cereus) has been studied at different phs and metal-ion concentrations. an enzyme group of pk(a) 6.52+/-0.1 is found to be required in its deprotonated form f ... | 2007 | 16961465 |
| the activity of the dinuclear cobalt-beta-lactamase from bacillus cereus in catalysing the hydrolysis of beta-lactams. | metallo-beta-lactamases are native zinc enzymes that catalyse the hydrolysis of beta-lactam antibiotics, but are also able to function with cobalt(ii) and require one or two metal-ions for catalytic activity. the hydrolysis of cefoxitin, cephaloridine and benzylpenicillin catalysed by cobcii (cobalt-substituted beta-lactamase from bacillus cereus) has been studied at different phs and metal-ion concentrations. an enzyme group of pk(a) 6.52+/-0.1 is found to be required in its deprotonated form f ... | 2007 | 16961465 |
| role of zinc content on the catalytic efficiency of b1 metallo beta-lactamases. | metallo beta-lactamases (mbetal) are enzymes naturally evolved by bacterial strains under the evolutionary pressure of beta-lactam antibiotic clinical use. they have a broad substrate spectrum and are resistant to all the clinically useful inhibitors, representing a potential risk of infection if massively disseminated. the mbetal scaffold is designed to accommodate one or two zinc ions able to activate a nucleophilic hydroxide for the hydrolysis of the beta-lactam ring. the role of zinc content ... | 2007 | 17305336 |
| competitive inhibitors of the cpha metallo-beta-lactamase from aeromonas hydrophila. | various inhibitors of metallo-beta-lactamases have been reported; however, none are effective for all subgroups. those that have been found to inhibit the enzymes of subclass b2 (catalytically active with one zinc) either contain a thiol (and show less inhibition towards this subgroup than towards the dizinc members of b1 and b3) or are inactivators behaving as substrates for the dizinc family members. the present work reveals that certain pyridine carboxylates are competitive inhibitors of cpha ... | 2007 | 17307979 |
| folding strategy to prepare co(ii)-substituted metallo-beta-lactamase l1. | in an effort to overcome previous problems with the preparation of co(ii)-substituted metallo-beta-lactamase l1, two strategies were undertaken. attempts to prepare co(ii)-substituted l1 using biological incorporation resulted in an enzyme that contained only 1 eq of cobalt and exhibited no catalytic activity. co(ii)-substituted l1 could be prepared by refolding metal-free l1 in the presence of co(ii), and the resulting enzyme contained 1.8 eq of cobalt, yielded a uv-vis spectrum consistent with ... | 2008 | 18445468 |
| engineered mononuclear variants in bacillus cereus metallo-beta-lactamase bcii are inactive. | metallo-beta-lactamases (mbetals) are zinc enzymes able to hydrolyze almost all beta-lactam antibiotics, rendering them inactive, at the same time endowing bacteria high levels of resistance. the design of inhibitors active against all classes of mbetals has been hampered by their structural diversity and by the heterogeneity in metal content in enzymes from different sources. bcii is the metallo-beta-lactamase from bacillus cereus, which is found in both the mononuclear and dinuclear forms. des ... | 2008 | 18652482 |
| zinc ion-induced domain organization in metallo-beta-lactamases: a flexible "zinc arm" for rapid metal ion transfer? | the reversible unfolding of metallo-beta-lactamase from chryseobacterium meningosepticum (blab) by guanidinium hydrochloride is best described by a three-state model including folded, intermediate, and unfolded states. the transformation of the folded apoenzyme into the intermediate state requires only very low denaturant concentrations, in contrast to the zn2-enzyme. similarly, circular dichroism spectra of both blab and metallo-beta-lactamase from bacillus cereus 569/h/9 (bcii) display distinc ... | 2009 | 19395380 |
| phospholipase plab of legionella pneumophila represents a novel lipase family: protein residues essential for lipolytic activity, substrate specificity, and hemolysis. | legionella pneumophila possesses several phospholipases capable of host cell manipulation and lung damage. recently, we discovered that the major cell-associated hemolytic phospholipase a (plab) shares no homology to described phospholipases and is dispensable for intracellular replication in vitro. nevertheless, here we show that plab is the major lipolytic activity in l. pneumophila cell infections and that plab utilizes a typical catalytic triad of ser-asp-his for effective hydrolysis of phos ... | 2009 | 19640837 |
| evolving carbapenemases: can medicinal chemists advance one step ahead of the coming storm? | | 2010 | 20121112 |
| oxa-134, a naturally occurring carbapenem-hydrolyzing class d beta-lactamase from acinetobacter lwoffii. | acinetobacter lwoffii, a species whose natural habitat is the human skin, intrinsically possesses a chromosomal gene encoding a carbapenem-hydrolyzing class d β-lactamase, oxa-134. this species may therefore constitute a reservoir for carbapenemase genes that may spread among other acinetobacter species. | 2010 | 20837764 |
| rapid pcr detection of mycoplasma hominis, ureaplasma urealyticum, and ureaplasma parvum. | objective. we compared laboratory developed real-time pcr assays for detection of mycoplasma hominis and for detection and differentiation of ureaplasma urealyticum and parvum to culture using genitourinary specimens submitted for m. hominis and ureaplasma culture. methods. 283 genitourinary specimens received in the clinical bacteriology laboratory for m. hominis and ureaplasma species culture were evaluated. nucleic acids were extracted using the total nucleic acid kit on the magna pure 2.0. 5 ... | 2013 | 26904723 |
| metal content of metallo-beta-lactamase l1 is determined by the bioavailability of metal ions. | in an effort to probe whether the metal content of metallo-beta-lactamase l1 is affected by metal ion bioavailability, l1 was overexpressed as mature protein (m-l1) and full-length (fl-l1) analogues, and the analogues were characterized with metal analyses, kinetics, and epr spectroscopy. fl-l1, containing the putative leader sequence, was localized in the periplasm of escherichia coli and shown to bind zn(ii) preferentially. the metal content of fl-l1 could be altered if the enzyme was overexpr ... | 2008 | 18597493 |
| lgt: a family of cytotoxic glucosyltransferases produced by legionella pneumophila. | legionella pneumophila is a facultative intracellular pathogen responsible for severe lung disease in humans, known as legionellosis or legionnaires' disease. previously, we reported on the approximately 60-kda glucosyltransferase (lgt1) from legionella pneumophila, which modified eukaryotic elongation factor 1a. in the present study, using l. pneumophila philadelphia-1, lens, paris, and corby genome databases, we identified several genes coding for proteins with considerable sequence homology t ... | 2008 | 18281405 |
| postgenomic scan of metallo-beta-lactamase homologues in rhizobacteria: identification and characterization of bjp-1, a subclass b3 ortholog from bradyrhizobium japonicum. | the diffusion of metallo-beta-lactamases (mbls) among clinically important human pathogens represents a therapeutic issue of increasing importance. however, the origin of these resistance determinants is largely unknown, although an important number of proteins belonging to the mbl superfamily have been identified in microbial genomes. in this work, we analyzed the distribution and function of genes encoding mbl-like proteins in the class rhizobiales. among 12 released complete genomes of member ... | 2006 | 16723554 |
| rapid method for enumeration of viable legionella pneumophila and other legionella spp. in water. | a sensitive and specific method has been developed to enumerate viable l. pneumophila and other legionella spp. in water by epifluorescence microscopy in a short period of time (a few hours). this method allows the quantification of l. pneumophila or other legionella spp. as well as the discrimination between viable and nonviable legionella. it simultaneously combines the specific detection of legionella cells using antibodies and a bacterial viability marker (chemchrome v6), the enumeration bei ... | 2005 | 16000824 |
| biochemical characterization of the thin-b metallo-beta-lactamase of janthinobacterium lividum. | the thin-b metallo-beta-lactamase, a subclass b3 enzyme produced by the environmental species janthinobacterium lividum, was overproduced in escherichia coli by means of a t7-based expression system. the enzyme was purified (>95%) by two ion-exchange chromatography steps and subjected to biochemical analysis. the native thin-b enzyme is a monomeric protein of 31 kda. it exhibits the highest catalytic efficiencies with carbapenem substrates and cephalosporins, except for cephaloridine, which acts ... | 2004 | 15561856 |
| biochemical characterization of cps-1, a subclass b3 metallo-β-lactamase from a chryseobacterium piscium soil isolate. | cps-1 is a subclass b3 metallo-β-lactamase from a chryseobacterium piscium isolate collected from soil, showing 68% amino acid identity to the gob-1 enzyme. cps-1 was overproduced in escherichia coli rosetta (de3), purified by chromatography, and biochemically characterized. this enzyme exhibits a broad-spectrum substrate profile, including penicillins, cephalosporins, and carbapenems, which overall resembles those of l1, gob-1, and acquired subclass b3 enzymes aim-1 and smb-1. | 2016 | 26666948 |
| zinc- and iron-dependent cytosolic metallo-beta-lactamase domain proteins exhibit similar zinc-binding affinities, independent of an atypical glutamate at the metal-binding site. | zipd (zinc phosphodiesterase; synonyms are elac, ecoz, rnasez and 3' trnase) and the iron-dependent redox enzyme flrd (flavorubredoxin) from escherichia coli represent prototypical cases of proteins sharing the metallo-beta-lactamase fold that require strict metal selectivity for catalytic activity, yet their metal selectivity has only been partially understood. in contrast with hydrolytic metallo-beta-lactamase proteins, iron-dependent flrd-like enzymes have an atypical glutamate ligand, which ... | 2005 | 15324305 |
| reclamation of ampicillin sensitivity for the genetic manipulation of legionella pneumophila. | research on legionella pneumophila, the causative agent of legionnaires' disease, has been hampered due to the lack of selectable markers for genetic manipulation. we report the construction of a mutant strain of l. pneumophila lacking loxa, a chromosomally encoded β-lactamase, that has enhanced sensitivity to ampicillin. also described are a method for converting legionella strains to ampicillin sensitivity and conditions for utilizing bla as a selectable marker. | 2012 | 22635996 |
| zinc- and iron-dependent cytosolic metallo-beta-lactamase domain proteins exhibit similar zinc-binding affinities, independent of an atypical glutamate at the metal-binding site. | zipd (zinc phosphodiesterase; synonyms are elac, ecoz, rnasez and 3' trnase) and the iron-dependent redox enzyme flrd (flavorubredoxin) from escherichia coli represent prototypical cases of proteins sharing the metallo-beta-lactamase fold that require strict metal selectivity for catalytic activity, yet their metal selectivity has only been partially understood. in contrast with hydrolytic metallo-beta-lactamase proteins, iron-dependent flrd-like enzymes have an atypical glutamate ligand, which ... | 2005 | 15324305 |
| cau-1, a subclass b3 metallo-beta-lactamase of low substrate affinity encoded by an ortholog present in the caulobacter crescentus chromosome. | the sequenced chromosome of caulobacter crescentus cb15 encodes a hypothetical protein that exhibits significant similarity (30 to 35% identical residues) to metallo-beta-lactamases of subclass b3. an allelic variant of this gene (divergent by 3% of its nucleotides) was cloned in escherichia coli from c. crescentus type strain dsm4727. expression studies confirmed the metallo-beta-lactamase activity of its product, cau-1. the enzyme produced in e. coli was purified by two ion-exchange chromatogr ... | 2002 | 12019096 |
| identification of legionella spp. in environmental water samples by scanvit-legionella™ method in spain. | rapid and more sensitive methods for the detection and quantification of viable legionella cells have been developed. in this paper, a comparative analysis of environmental water samples using the scanvit-legionella™ method and the traditional "gold standard" method of culturing is realised indicating the usefulness of the scanvit method. the scanvit-legionella™ method was performed on environmental water samples from different locations of huesca region (spain). legionella micro-colonies should ... | 2013 | 24426100 |
| a new oligonucleotide microarray for detection of pathogenic and non-pathogenic legionella spp. | legionella pneumophila has been recognized as the major cause of legionellosis since the discovery of the deadly disease. legionella spp. other than l. pneumophila were later found to be responsible to many non-pneumophila infections. the non-l. pneumophila infections are likely under-detected because of a lack of effective diagnosis. in this report, we have sequenced the 16s-23s rrna gene internal transcribed spacer (its) of 10 legionella species and subspecies, including l. anisa, l. bozemanii ... | 2014 | 25469776 |
| characterization of oxa-29 from legionella (fluoribacter) gormanii: molecular class d beta-lactamase with unusual properties. | a class d beta-lactamase determinant was isolated from the genome of legionella (fluoribacter) gormanii atcc 33297(t). the enzyme, named oxa-29, is quite divergent from other class d beta-lactamases, being more similar (33 to 43% amino acid identity) to those of groups iii (oxa-1) and iv (oxa-9, oxa-12, oxa-18, and oxa-22) than to other class d enzymes (21 to 24% sequence identity). phylogenetic analysis confirmed the closer ancestry of oxa-29 with members of the former groups. the oxa-29 enzyme ... | 2001 | 11709332 |
| legionellosis outbreak associated with a hotel fountain. | background. in august 2012, the chicago department of public health (cdph) was notified of acute respiratory illness, including 1 fatality, among a group of meeting attendees who stayed at a chicago hotel during july 30-august 3, 2012. suspecting legionnaires' disease (ld), cdph advised the hotel to close their swimming pool, spa, and decorative lobby fountain and began an investigation. methods. case finding included notification of individuals potentially exposed during july 16-august 15, 20 ... | 2015 | 26716104 |
| the legionella (fluoribacter) gormanii metallo-beta-lactamase: a new member of the highly divergent lineage of molecular-subclass b3 beta-lactamases. | a metallo-beta-lactamase determinant was cloned from a genomic library of legionella (fluoribacter) gormanii atcc 33297(t) constructed in the plasmid vector pacyc184 and transformed into escherichia coli dh5alpha, by screening for clones showing a reduced susceptibility to imipenem. the product of the cloned determinant, named fez-1, contains a 30-kda polypeptide and exhibits an isoelectric ph of 7.6. sequencing revealed that fez-1 is a molecular-class b beta-lactamase which shares the closest s ... | 2000 | 10817705 |
| legionella gormanii sp. nov. | a new species of legionella was isolated from soil collected from a creek bank. the name legionella gormanii sp. nov. is proposed. | 1980 | 7276144 |
| biochemical properties of beta-lactamase produced by legionella gormanii. | beta-lactamase was purified from a strain of legionella gormanii. the molecular weight of the purified enzyme was 25,000, and its isoelectric point was 10.5. the enzyme hydrolyzed oxyiminocephalosporins, cephamycins, penicillins, and imipenem. the enzyme activity was inhibited by edta, hg2+, and cu2+, but not by clavulanic acid, sulbactam, or imipenem. | 1986 | 3488020 |
| chemotaxonomic differentiation of legionellae by detection and characterization of aminodideoxyhexoses and other unique sugars using gas chromatography-mass spectrometry. | legionellae have been differentiated previously by analyzing their carbohydrate contents by gas chromatography with flame ionization detection. in the present study, total ion mode gas chromatography-mass spectrometry (gc-ms) was used to detect a number of unusual sugars, including one that is structurally related to o-methyldideoxyheptoses. increased sensitivity and selectivity for carbohydrate detection was achieved by selected ion-monitoring gc-ms. two of the uncommon sugars previously discov ... | 1990 | 2324276 |
| genetic and biochemical characterization of an acquired subgroup b3 metallo-β-lactamase gene, blaaim-1, and its unique genetic context in pseudomonas aeruginosa from australia. | three clinical pseudomonas aeruginosa isolates (wch2677, wch2813, and wch2837) isolated from the women's and children's hospital, adelaide, australia, produced a metallo-β-lactamase (mbl)-positive etest result. all isolates were pcr negative for known mbl genes. a gene bank was created, and an mbl gene, designated bla(aim-1), was cloned and fully characterized. the encoded enzyme, aim-1, is a group b3 mbl that has the highest level of identity to thin-b and l1. it is chromosomal and flanked by t ... | 2012 | 22985886 |
| structure of apo- and monometalated forms of ndm-1--a highly potent carbapenem-hydrolyzing metallo-β-lactamase. | the new delhi metallo-β-lactamase (ndm-1) gene makes multiple pathogenic microorganisms resistant to all known β-lactam antibiotics. the rapid emergence of ndm-1 has been linked to mobile plasmids that move between different strains resulting in world-wide dissemination. biochemical studies revealed that ndm-1 is capable of efficiently hydrolyzing a wide range of β-lactams, including many carbapenems considered as "last resort" antibiotics. the crystal structures of metal-free apo- and monozinc ... | 2011 | 21931780 |
| structure-based phylogeny of the metallo-beta-lactamases. | the metallo-beta-lactamases fall into two groups: ambler class b subgroups b1 and b2 and ambler class b subgroup b3. the two groups are so distantly related that there is no detectable sequence homology between members of the two different groups, but homology is clearly detectable at the protein structure level. the multiple structure alignment program maps has been used to align the structures of eight metallo-beta-lactamases and five structurally homologous proteins from the metallo-beta-lact ... | 2005 | 15980349 |
| update of the standard numbering scheme for class b beta-lactamases. | | 2004 | 15215079 |
| standard numbering scheme for class b beta-lactamases. | | 2001 | 11181339 |
| virulence determinants, drug resistance and mobile genetic elements of laribacter hongkongensis: a genome-wide analysis. | | 2011 | 21711902 |
| metallo-beta-lactamase production by pseudomonas otitidis: a species-related trait. | susceptibility to several β-lactams and β-lactamase production was investigated in a collection of 20 strains of pseudomonas otitidis, a new pseudomonas species that has been recently recognized in association with otic infections in humans. all strains appeared to be susceptible to piperacillin, cefotaxime, ceftazidime, and aztreonam, while resistance or decreased susceptibility to carbapenems was occasionally observed. all strains were found to express metallo-β-lactamase (mbl) activity and to ... | 2010 | 21060106 |
| metallo-beta-lactamase production by pseudomonas otitidis: a species-related trait. | susceptibility to several β-lactams and β-lactamase production was investigated in a collection of 20 strains of pseudomonas otitidis, a new pseudomonas species that has been recently recognized in association with otic infections in humans. all strains appeared to be susceptible to piperacillin, cefotaxime, ceftazidime, and aztreonam, while resistance or decreased susceptibility to carbapenems was occasionally observed. all strains were found to express metallo-β-lactamase (mbl) activity and to ... | 2010 | 21060106 |
| high-resolution crystal structure of the subclass b3 metallo-beta-lactamase bjp-1: rational basis for substrate specificity and interaction with sulfonamides. | metallo-β-lactamases (mbls) are important enzymatic factors in resistance to β-lactam antibiotics that show important structural and functional heterogeneity. bjp-1 is a subclass b3 mbl determinant produced by bradyrhizobium japonicum that exhibits interesting properties. bjp-1, like cau-1 of caulobacter vibrioides, overall poorly recognizes β-lactam substrates and shows an unusual substrate profile compared to other mbls. in order to understand the structural basis of these properties, the crys ... | 2010 | 20696874 |
| distribution of legionella species from environmental water sources of public facilities and genetic diversity of l. pneumophila serogroup 1 in south korea. | a total of 560 legionella species were isolated from environmental water sources from public facilities from june to september 2008 throughout south korea. the distribution of legionella isolates was investigated according to geographical region, facility type, and sample type. the genetic diversity of 104 isolates of legionella pneumophila serogroup 1 (sg 1) was analyzed by sequence-based typing (sbt). l. pneumophila was distributed broadly throughout korea, accounting for 85.0% of the isolates ... | 2010 | 20693456 |
| catalytic role of the metal ion in the metallo-beta-lactamase gob. | metallo-beta-lactamases (mbetals) stand as one of the main mechanisms of bacterial resistance toward carbapenems. the rational design of an inhibitor for mbetals has been limited by an incomplete knowledge of their catalytic mechanism and by the structural diversity of their active sites. here we show that the mbetal gob from elizabethkingia meningoseptica is active as a monometallic enzyme by using different divalent transition metal ions as surrogates of the native zn(ii) ion. of the metal der ... | 2010 | 20007696 |
| catalytic role of the metal ion in the metallo-beta-lactamase gob. | metallo-beta-lactamases (mbetals) stand as one of the main mechanisms of bacterial resistance toward carbapenems. the rational design of an inhibitor for mbetals has been limited by an incomplete knowledge of their catalytic mechanism and by the structural diversity of their active sites. here we show that the mbetal gob from elizabethkingia meningoseptica is active as a monometallic enzyme by using different divalent transition metal ions as surrogates of the native zn(ii) ion. of the metal der ... | 2010 | 20007696 |
| crystal structure of the mobile metallo-β-lactamase aim-1 from pseudomonas aeruginosa: insights into antibiotic binding and the role of gln157. | metallo-β-lactamase (mbl) genes confer resistance to virtually all β-lactam antibiotics and are rapidly disseminated by mobile genetic elements in gram-negative bacteria. mbls belong to three different subgroups, b1, b2, and b3, with the mobile mbls largely confined to subgroup b1. the b3 mbls are a divergent subgroup of predominantly chromosomally encoded enzymes. aim-1 (adelaide imipenmase 1) from pseudomonas aeruginosa was the first b3 mbl to be identified on a readily mobile genetic element. ... | 2012 | 22664968 |
| structural insights into the subclass b3 metallo-β-lactamase smb-1 and the mode of inhibition by the common metallo-β-lactamase inhibitor mercaptoacetate. | a novel subclass b3 metallo-β-lactamase (mbl), smb-1, recently identified from a serratia marcescens clinical isolate, showed a higher hydrolytic activity against a wide range of β-lactams than did the other subclass b3 mbls, i.e., bjp-1 and fez-1, from environmental bacteria. to identify the mechanism underlying the differences in substrate specificity among the subclass b3 mbls, we determined the structure of smb-1, using 1.6-å diffraction data. consequently, we found that smb-1 reserves a spa ... | 2013 | 23070156 |
| structural basis of metallo-β-lactamase inhibition by captopril stereoisomers. | β-lactams are the most successful antibacterials, but their effectiveness is threatened by resistance, most importantly by production of serine- and metallo-β-lactamases (mbls). mbls are of increasing concern because they catalyze the hydrolysis of almost all β-lactam antibiotics, including recent-generation carbapenems. clinically useful serine-β-lactamase inhibitors have been developed, but such inhibitors are not available for mbls. l-captopril, which is used to treat hypertension via angiote ... | 2015 | 26482303 |
| structural basis of metallo-β-lactamase inhibition by captopril stereoisomers. | β-lactams are the most successful antibacterials, but their effectiveness is threatened by resistance, most importantly by production of serine- and metallo-β-lactamases (mbls). mbls are of increasing concern because they catalyze the hydrolysis of almost all β-lactam antibiotics, including recent-generation carbapenems. clinically useful serine-β-lactamase inhibitors have been developed, but such inhibitors are not available for mbls. l-captopril, which is used to treat hypertension via angiote ... | 2015 | 26482303 |
| structural basis for carbapenem-hydrolyzing mechanisms of carbapenemases conferring antibiotic resistance. | carbapenems (imipenem, meropenem, biapenem, ertapenem, and doripenem) are β-lactam antimicrobial agents. because carbapenems have the broadest spectra among all β-lactams and are primarily used to treat infections by multi-resistant gram-negative bacteria, the emergence and spread of carbapenemases became a major public health concern. carbapenemases are the most versatile family of β-lactamases that are able to hydrolyze carbapenems and many other β-lactams. according to the dependency of dival ... | 2015 | 25938965 |
| isolation of legionella pneumophila from pluvial floods by amoebal coculture. | viable legionella pneumophila bacteria were isolated by amoebal coculture from pluvial floods after intense rainfall and from water collected at sewage treatment plants. several isolated l. pneumophila strains belonged to sequence types that have been previously identified in patients. | 2012 | 22467504 |
| development of a dna microarray method for detection and identification of all 15 distinct o-antigen forms of legionella pneumophila. | legionella is ubiquitous in many environments. at least 50 species and 70 serogroups of the gram-negative bacterium have been identified. of the 50 species, 20 are pathogenic, and legionella pneumophila is responsible for the great majority (approximately 90%) of the legionnaires' disease cases that occur. furthermore, of the 15 l. pneumophila serogroups identified, o1 alone causes more than 84% of the legionnaires' disease cases that occur worldwide. rapid and reliable assays for the detection ... | 2013 | 23974134 |
| oligomerization inhibits legionella pneumophila plab phospholipase a activity. | the intracellularly replicating lung pathogen legionella pneumophila consists of an extraordinary variety of phospholipases, including at least 15 different phospholipases a (pla). among them, plab, the first characterized member of a novel lipase family, is a hemolytic virulence factor that exhibits the most prominent pla activity in l. pneumophila. we analyzed here protein oligomerization, the importance of oligomerization for activity, addressed further essential regions for activity within t ... | 2014 | 24811180 |
| the mechanisms of catalysis by metallo beta-lactamases. | class b beta-lactamases or metallo-beta-lactamases (mbls) require zinc ions to catalyse the hydrolysis of beta-lactam antibiotics such as penicillins, cephalosporins, carbapenems, and cephamycins. there are no clinically useful inhibitors against mbls which are responsible for the resistance of some bacteria to antibiotics. there are two metal-ion binding sites that have different zinc ligands but the exact roles of the metal-ion remain controversial, and distinguishing between their relative im ... | 2008 | 18551183 |
| crystal structure of human persulfide dioxygenase: structural basis of ethylmalonic encephalopathy. | the ethylmalonic encephalopathy protein 1 (ethe1) catalyses the oxygen-dependent oxidation of glutathione persulfide (gssh) to give persulfite and glutathione. mutations to the hethe1 gene compromise sulfide metabolism leading to the genetic disease ethylmalonic encephalopathy. hethe1 is a mono-iron binding member of the metallo-β-lactamase (mbl) fold superfamily. we report crystallographic analysis of hethe1 in complex with iron to 2.6 å resolution. hethe1 contains an αββα mbl-fold, which suppo ... | 2015 | 25596185 |