Publications
| Title | Abstract | Year Filter | PMID(sorted descending) Filter |
|---|
| kinetic and spectral parameters of interaction of citrobacter freundii methionine γ-lyase with amino acids. | kinetic parameters of citrobacter freundii methionine γ-lyase were determined with substrates in γ-elimination reactions as well as the inhibition of the enzyme in the γ-elimination of l-methionine by amino acids with different structure. the data indicate an important contribution of the sulfur atom and methylene groups to the efficiency of binding of substrates and inhibitors. the rate constants of the enzyme-catalyzed exchange of c-α- and c-β-protons with deuterium were determined, as well as ... | 2010 | 21166645 |
| can we use imipenem and meropenem vitek 2 mics for detection of suspected kpc and other-carbapenemase producers among species of enterobacteriaceae? | imipenem and meropenem vitek 2 mics were evaluated for a panel of 104 enterobacteriaceae for identification of carbapenemase producers. the sensitivity and specificity values for the new clsi interpretative criteria (clsi document m100-s20-u, 2010) were 98% and 83% for imipenem and 76% and 83% for meropenem, respectively. we propose an algorithm that is highly sensitive (98%) and specific (94%) for carbapenemase screening based on the combined use of imipenem and meropenem mics. | 2011 | 21159944 |
| the binding specificity of the marker antibodies tra-1-60 and tra-1-81 reveals a novel pluripotency associated type 1 lactosamine epitope. | the expression of the epitopes recognized by the monoclonal antibodies tra-1-60 and tra-1-81 is routinely used to assess the pluripotency status of human embryonic stem cells (hescs) and induced pluripotent stem (ips) cells. although it is known that the epitopes recognized by tra-1-60 and tra-1-81 are carbohydrates, the exact molecular identity of these epitopes has been unclear. glycan array analysis with more than 500 oligosaccharide structures revealed specific binding of tra-1-60 and tra-1- ... | 2010 | 21159783 |
| the binding specificity of the marker antibodies tra-1-60 and tra-1-81 reveals a novel pluripotency associated type 1 lactosamine epitope. | the expression of the epitopes recognized by the monoclonal antibodies tra-1-60 and tra-1-81 is routinely used to assess the pluripotency status of human embryonic stem cells (hescs) and induced pluripotent stem (ips) cells. although it is known that the epitopes recognized by tra-1-60 and tra-1-81 are carbohydrates, the exact molecular identity of these epitopes has been unclear. glycan array analysis with more than 500 oligosaccharide structures revealed specific binding of tra-1-60 and tra-1- ... | 2010 | 21159783 |
| novel genetic environment of the plasmid-mediated kpc-3 gene detected in escherichia coli and citrobacter freundii isolates from china. | the imipenem and meropenem-resistant strains citrobacter freundii hs70 and escherichia coli hs510 were isolated from patients in shanghai, china. by isoelectric focusing, pcr amplification and sequencing, these strains were each found to produce four β-lactamases: tem-1, kpc-3, shv-7 and ctx-m-14. a conjugation experiment and plasmid restriction digestion revealed that the bla (kpc-3) gene was located on the same plasmid in both isolates. bidirectional primer walking sequencing showed that the n ... | 2010 | 21153909 |
| increased expression of carbonic anhydrase i in the synovium of patients with ankylosing spondylitis. | one of the most distinctive features of ankylosing spondylitis (as) is new bone formation and bone resorption at sites of chronic inflammation. previous studies have indicated that the hyperplasia and inflammation of synovial tissues are significantly related to the pathogenic process of as. the present study used a proteomic approach to identify novel as-specific proteins by simultaneously comparing the expression profiles of synovial membranes from patients with as, rheumatoid arthritis (ra) a ... | 2010 | 21143847 |
| water microbiology. bacterial pathogens and water. | water is essential to life, but many people do not have access to clean and safe drinking water and many die of waterborne bacterial infections. in this review a general characterization of the most important bacterial diseases transmitted through water-cholera, typhoid fever and bacillary dysentery-is presented, focusing on the biology and ecology of the causal agents and on the diseases' characteristics and their life cycles in the environment. the importance of pathogenic escherichia coli str ... | 2010 | 21139855 |
| multiplex real-time pcr assay for detection and classification of klebsiella pneumoniae carbapenemase gene (bla kpc) variants. | carbapenem resistance mediated by plasmid-borne klebsiella pneumoniae carbapenemases (kpc) is an emerging problem of significant clinical importance in gram-negative bacteria. multiple kpc gene variants (bla(kpc)) have been reported, with kpc-2 (bla(kpc-2)) and kpc-3 (bla(kpc-3)) associated with epidemic outbreaks in new york city and various international settings. here, we describe the development of a multiplex real-time pcr assay using molecular beacons (mb-pcr) for rapid and accurate identi ... | 2010 | 21123529 |
| laboratory detection of extended-spectrum-beta-lactamase-producing enterobacteriaceae: evaluation of two screening agar plates and two confirmation techniques. | the worldwide prevalence of extended-spectrum-beta-lactamase-producing esbl-producing enterobacteriaceae (esbl-e) is increasing, making the need for optimized detection techniques more urgent. in this study we investigated the performance of two esbl-e screening and two esbl-e confirmation techniques. in accordance with the dutch national guidelines (www.wip.nl), a collection of 642 highly resistant enterobacteriaceae strains, as identified by vitek2, was used to test the performances of two scr ... | 2010 | 21123527 |
| emergence of klebsiella pneumoniae carbapenemase-producing bacteria. | klebsiella pneumoniae carbapenemase (kpc)-producing bacteria are a group of emerging highly drug-resistant gram-negative bacilli causing infections associated with significant morbidity and mortality. once confined to outbreaks in the northeastern united states (us), they have spread throughout the us and most of the world. kpcs are an important mechanism of resistance for an increasingly wide range of gram-negative bacteria and are no longer limited to k pneumoniae. kpc-producing bacteria are o ... | 2011 | 21119555 |
| detection of ndm-1-producing klebsiella pneumoniae in kenya. | seven carbapenem-resistant ndm-1-positive klebsiella pneumoniae isolates were recovered from patients hospitalized between 2007 and 2009 in different wards at a referral and tertiary care center in nairobi. most of the isolates were obtained from urine. all isolates carried the bla(ndm-1) carbapenemase gene previously reported from india, pakistan, and the united kingdom. these isolates were clonally related and expressed many other resistance determinants, including β-lactamases ctx-m-15, oxa-1 ... | 2010 | 21115785 |
| detection of ndm-1-producing klebsiella pneumoniae in kenya. | seven carbapenem-resistant ndm-1-positive klebsiella pneumoniae isolates were recovered from patients hospitalized between 2007 and 2009 in different wards at a referral and tertiary care center in nairobi. most of the isolates were obtained from urine. all isolates carried the bla(ndm-1) carbapenemase gene previously reported from india, pakistan, and the united kingdom. these isolates were clonally related and expressed many other resistance determinants, including β-lactamases ctx-m-15, oxa-1 ... | 2010 | 21115785 |
| vi-crm 197 as a new conjugate vaccine against salmonella typhi. | an efficacious, low cost vaccine against typhoid fever, especially for young children, would make a major impact on disease burden in developing countries. the virulence capsular polysaccharide of salmonella typhi (vi) coupled to recombinant mutant pseudomonas aeruginosa exoprotein a (vi-repa) has been shown to be highly efficacious. we investigated the use of carrier proteins included in infant vaccines, standardized the conjugation process and developed key assays required for routine lot rele ... | 2010 | 21115057 |
| chronic and acute infection of the gall bladder by salmonella typhi: understanding the carrier state. | despite major treatment and prevention efforts, millions of new typhoid infections occur worldwide each year. for a subset of infected individuals, salmonella enterica subsp. enterica serovar typhi colonizes the gall bladder and remains there long after symptoms subside, serving as a reservoir for the further spread of the disease. in this progress article, we explore recent advances in our understanding of the mechanisms by which salmonella spp.--predominantly s. typhi--colonize and persist in ... | 2010 | 21113180 |
| chronic and acute infection of the gall bladder by salmonella typhi: understanding the carrier state. | despite major treatment and prevention efforts, millions of new typhoid infections occur worldwide each year. for a subset of infected individuals, salmonella enterica subsp. enterica serovar typhi colonizes the gall bladder and remains there long after symptoms subside, serving as a reservoir for the further spread of the disease. in this progress article, we explore recent advances in our understanding of the mechanisms by which salmonella spp.--predominantly s. typhi--colonize and persist in ... | 2010 | 21113180 |
| characterisation of pdus, the pdu metabolosome corrin reductase, and evidence of substructural organisation within the bacterial microcompartment. | pdus is a corrin reductase and is required for the reactivation of the cobalamin-dependent diol dehydratase. it is one component encoded within the large propanediol utilisation (pdu) operon, which is responsible for the catabolism of 1,2-propanediol within a self-assembled proteinaceous bacterial microcompartment. the enzyme is responsible for the reactivation of the cobalamin coenzyme required by the diol dehydratase. the gene for the cobalamin reductase from citrobacter freundii (pdus) has be ... | 2010 | 21103360 |
| whole-genome analysis of salmonella enterica serovar typhimurium t000240 reveals the acquisition of a genomic island involved in multidrug resistance via is1 derivatives on the chromosome. | salmonella enterica serovar typhimurium is frequently associated with life-threatening systemic infections, and the recent global emergence of multidrug resistance in s. enterica isolates from agricultural and clinical settings has raised concerns. in this study, we determined the whole-genome sequence of fluoroquinolone-resistant s. enterica serovar typhimurium t000240 strain (dt12) isolated from human gastroenteritis in 2000. comparative genome analysis revealed that t000240 displays high sequ ... | 2010 | 21098248 |
| whole-genome analysis of salmonella enterica serovar typhimurium t000240 reveals the acquisition of a genomic island involved in multidrug resistance via is1 derivatives on the chromosome. | salmonella enterica serovar typhimurium is frequently associated with life-threatening systemic infections, and the recent global emergence of multidrug resistance in s. enterica isolates from agricultural and clinical settings has raised concerns. in this study, we determined the whole-genome sequence of fluoroquinolone-resistant s. enterica serovar typhimurium t000240 strain (dt12) isolated from human gastroenteritis in 2000. comparative genome analysis revealed that t000240 displays high sequ ... | 2010 | 21098248 |
| serendipitous discovery of α-hydroxyalkyl esters as β-lactamase substrates. | o-(1-carboxy-1-alkyloxycarbonyl) hydroxamates were found to spontaneously decarboxylate in aqueous neutral buffer to form o-(2-hydroxyalkylcarbonyl) hydroxamates. while the former molecules do not react rapidly with serine β-lactamases, the latter are quite good substrates of representative class a and c, but not d, enzymes, and particularly of a class c enzyme. the enzymes catalyze hydrolysis of these compounds to a mixture of the α-hydroxy acid and hydroxamate. analogous compounds containing a ... | 2010 | 21087009 |
| ct differentiation of pyogenic liver abscesses caused by klebsiella pneumoniae vs non-klebsiella pneumoniae. | objective: klebsiella pneumoniae is one of the organisms most commonly isolated from pyogenic liver abscesses in asian populations. we compared ct findings in liver abscesses caused by k. pneumoniae with those caused by other bacterial pathogens. methods: of 214 patients with liver abscesses examined over a 5 year period, 129 patients with positive blood or aspirate cultures were enrolled. the patients were divided into two groups: the k. pneumoniae monomicrobial liver abscess (kla) group (n = 5 ... | 2010 | 21081584 |
| rmtd2, a new allele of a 16s rrna methylase gene, has been present in enterobacteriaceae isolates from argentina for more than a decade. | the first allele of a 16s rrna methyltransferase gene, rmtd2, conferring very high resistance to all clinically available aminoglycosides, was detected in 7/1,064 enterobacteria collected in 2007. rmtd2 was located on a conjugative plasmid in a tn2670-like element inside a structure similar to that of rmtd1 but probably having an independent assembly. rmtd2 has been found since 1996 to 1998 mainly in enterobacter and citrobacter isolates, suggesting a possible reservoir in these genera. this pre ... | 2010 | 21078935 |
| rmtd2, a new allele of a 16s rrna methylase gene, has been present in enterobacteriaceae isolates from argentina for more than a decade. | the first allele of a 16s rrna methyltransferase gene, rmtd2, conferring very high resistance to all clinically available aminoglycosides, was detected in 7/1,064 enterobacteria collected in 2007. rmtd2 was located on a conjugative plasmid in a tn2670-like element inside a structure similar to that of rmtd1 but probably having an independent assembly. rmtd2 has been found since 1996 to 1998 mainly in enterobacter and citrobacter isolates, suggesting a possible reservoir in these genera. this pre ... | 2010 | 21078935 |
| companion animals: a relevant source of extended-spectrum β-lactamase-producing fluoroquinolone-resistant citrobacter freundii. | 2010 | 21074371 | |
| bacterial decolorization of black liquor in axenic and mixed condition and characterization of metabolites. | the pulping byproducts (black liquor) cause serious environmental problem due to its high pollution load. in order to search the degradability of black liquor, the potential bacterial strains citrobacter freundii (fj581026) and citrobacter sp. (fj581023) were applied in axenic and mixed condition. results revealed that the mixed bacterial culture are more effective than axenic condition and can reduce 82% cod, 79% aox, 79% color and 60% lignin after 144 h of incubation period. additionally, the ... | 2010 | 21061144 |
| light-enhanced catalysis by pyridoxal phosphate-dependent aspartate aminotransferase. | the mechanisms of pyridoxal 5'-phosphate (plp)-dependent enzymes require substrates to form covalent "external aldimine" intermediates, which absorb light strongly between 410 and 430 nm. aspartate aminotransferase (aat) is a prototypical plp-dependent enzyme that catalyzes the reversible interconversion of aspartate and α-ketoglutarate with oxalacetate and glutamate. from kinetic isotope effects studies, it is known that deprotonation of the aspartate external aldimine c(α)-h bond to give a car ... | 2010 | 21058708 |
| clinical features and outcome of patients with irak-4 and myd88 deficiency. | autosomal recessive interleukin-1 receptor-associated kinase (irak)-4 and myeloid differentiation factor (myd)88 deficiencies impair toll-like receptor (tlr)- and interleukin-1 receptor-mediated immunity. we documented the clinical features and outcome of 48 patients with irak-4 deficiency and 12 patients with myd88 deficiency, from 37 kindreds in 15 countries.the clinical features of irak-4 and myd88 deficiency were indistinguishable. there were no severe viral, parasitic, and fungal diseases, ... | 2010 | 21057262 |
| revisiting human il-12rβ1 deficiency: a survey of 141 patients from 30 countries. | interleukin-12 receptor β1 (il-12rβ1) deficiency is the most common form of mendelian susceptibility to mycobacterial disease (msmd). we undertook an international survey of 141 patients from 102 kindreds in 30 countries. among 102 probands, the first infection occurred at a mean age of 2.4 years. in 78 patients, this infection was caused by bacille calmette-guérin (bcg; n = 65), environmental mycobacteria (em; also known as atypical or nontuberculous mycobacteria) (n = 9) or mycobacterium tuber ... | 2010 | 21057261 |
| investigation of the cytotoxic capacity of some adherent opportunistic enterobacterial strains by the mtt assay and transmission electron microscopy. | the purpose of this study was to determine the cytotoxic effect on caco-2 intestinal cells of dialysates obtained from bacterial cultures of some enterobacterial opportunistic strains with different sources of isolation (food, stool culture, acute diarrhoea, urine culture), previously tested and selected for their intensive adherence and invasion capacity to the cellular substratum and also for their cytotoxic effect on cell monolayers. in this study the level of cytotoxicity was measured quanti ... | 2010 | 21053782 |
| use of pcr coupled with electrospray ionization mass spectrometry for rapid identification of bacterial and yeast bloodstream pathogens from blood culture bottles. | sepsis is among the top 10 causes of mortality in the united states. rapid administration of antibiotics is one of the most important contributors to patient survival, yet only a limited number of methods exist for rapid identification of microbes cultivated from bloodstream infections, which can lead to sepsis. while traditional single-target molecular methods have been shown to greatly improve survival for septic patients by enabling rapid deescalation of broad-spectrum antibiotics, multiplex ... | 2010 | 21048006 |
| use of pcr coupled with electrospray ionization mass spectrometry for rapid identification of bacterial and yeast bloodstream pathogens from blood culture bottles. | sepsis is among the top 10 causes of mortality in the united states. rapid administration of antibiotics is one of the most important contributors to patient survival, yet only a limited number of methods exist for rapid identification of microbes cultivated from bloodstream infections, which can lead to sepsis. while traditional single-target molecular methods have been shown to greatly improve survival for septic patients by enabling rapid deescalation of broad-spectrum antibiotics, multiplex ... | 2010 | 21048006 |
| activities of nxl104 combinations with ceftazidime and aztreonam against carbapenemase-producing enterobacteriaceae. | combinations of nxl104 with ceftazidime and aztreonam were tested against carbapenem-resistant members of the enterobacteriaceae. ceftazidime-nxl104 was active against strains with the oxa-48 enzyme or with combinations of impermeability and an extended-spectrum β-lactamase (esbl) or ampc enzyme and also against most klebsiella spp. with the kpc enzyme, but metallo-β-lactamase producers were resistant. aztreonam-nxl104 was active against all carbapenemase producers at 4 and 4 μg/ml, including th ... | 2010 | 21041502 |
| activities of nxl104 combinations with ceftazidime and aztreonam against carbapenemase-producing enterobacteriaceae. | combinations of nxl104 with ceftazidime and aztreonam were tested against carbapenem-resistant members of the enterobacteriaceae. ceftazidime-nxl104 was active against strains with the oxa-48 enzyme or with combinations of impermeability and an extended-spectrum β-lactamase (esbl) or ampc enzyme and also against most klebsiella spp. with the kpc enzyme, but metallo-β-lactamase producers were resistant. aztreonam-nxl104 was active against all carbapenemase producers at 4 and 4 μg/ml, including th ... | 2010 | 21041502 |
| surveillance of antimicrobial susceptibility of aerobic and facultative gram-negative bacilli isolated from patients with intra-abdominal infections in china: the 2002-2009 study for monitoring antimicrobial resistance trends (smart). | the objective of this study was to investigate the distribution and susceptibility of aerobic and facultative gram-negative bacilli (gnb) isolated from patients with intra-abdominal infections (iais) in china. from 2002 to 2009, minimum inhibitory concentrations of 14 antibiotics for 3420 aerobic and facultative gnb from up to eight hospitals in six cities were determined by the broth microdilution method. enterobacteriaceae comprised 82.9% (2834/3420) of the total isolates, with escherichia col ... | 2010 | 21036547 |
| occurrence of gram-negative bacteria in hens' eggs depending on their source and storage conditions. | the aim of this study was to analyse the qualitative composition of gram-negative microbes, mainly of the family enterobacteriaceae, including pathogenic bacteria such as salmonella, in the albumens and yolks and on the shells of hens' eggs, depending on their source and on the temperature and duration of their storage. a total of 375 table eggs were studied, from a large-scale poultry farm, a small-scale poultry farm and a supermarket. each group was divided into 5 subgroups according to the te ... | 2010 | 21033566 |
| the oxidation of glycerol by escherichia freundii. | 1946 | 20987014 | |
| extremely drug-resistant citrobacter freundii isolate producing ndm-1 and other carbapenemases identified in a patient returning from india. | 2010 | 20974865 | |
| co-regulation of {beta}-lactam resistance, alginate production and quorum sensing in pseudomonas aeruginosa. | development of β-lactam resistance, production of alginate and modulation of virulence factor expression that alters host immune responses are the hallmarks of chronic pseudomonas aeruginosa infection in cystic fibrosis patients. in this study, we propose that a co-regulatory network exists between these mechanisms. we compared the promoter activities of ampr, algt/u, lasr, lasi, rhlr, rhli and lasa genes, representing the β-lactam antibiotic resistance master regulatory gene, the alginate switc ... | 2010 | 20965918 |
| emergence of klebsiella pneumoniae coproducing kpc-2 and 16s rrna methylase arma in poland. | a klebsiella pneumoniae epidemic strain that coproduced carbapenemase kpc-2 (k. pneumoniae carbapenemase 2) and 16s rrna methylase arma has emerged in poland. four nonduplicate isolates from patients in a hospital in warsaw, poland, were found to carry the bla(kpc-2) and arma genes on ca. 50-kb and 90-kb plasmids, respectively. tn4401 with a 100-bp deletion in the variable region was detected in all the isolates. xbai pulsed-field gel electrophoresis (pfge) revealed 93.2% similarity of the isola ... | 2010 | 20956599 |
| emergence of klebsiella pneumoniae coproducing kpc-2 and 16s rrna methylase arma in poland. | a klebsiella pneumoniae epidemic strain that coproduced carbapenemase kpc-2 (k. pneumoniae carbapenemase 2) and 16s rrna methylase arma has emerged in poland. four nonduplicate isolates from patients in a hospital in warsaw, poland, were found to carry the bla(kpc-2) and arma genes on ca. 50-kb and 90-kb plasmids, respectively. tn4401 with a 100-bp deletion in the variable region was detected in all the isolates. xbai pulsed-field gel electrophoresis (pfge) revealed 93.2% similarity of the isola ... | 2010 | 20956599 |
| marine myxobacteria as a source of antibiotics--comparison of physiology, polyketide-type genes and antibiotic production of three new isolates of enhygromyxa salina. | three myxobacterial strains, designated swb004, swb005 and swb006, were obtained from beach sand samples from the pacific ocean and the north sea. the strains were cultivated in salt water containing media and subjected to studies to determine their taxonomic status, the presence of genes for the biosynthesis of polyketides and antibiotic production. 16s rdna sequence analysis revealed the type strain enhygromyxa salina shk-1(t) as their closest homolog, displaying between 98% (swb005) and 99% ( ... | 2010 | 20948900 |
| design, synthesis, crystal structures, and antimicrobial activity of sulfonamide boronic acids as β-lactamase inhibitors. | we investigated a series of sulfonamide boronic acids that resulted from the merging of two unrelated ampc β-lactamase inhibitor series. the new boronic acids differed in the replacement of the canonical carboxamide, found in all penicillin and cephalosporin antibiotics, with a sulfonamide. surprisingly, these sulfonamides had a highly distinct structure-activity relationship from the previously explored carboxamides, high ligand efficiencies (up to 0.91), and k(i) values down to 25 nm and up to ... | 2010 | 20945905 |
| suffering for water, suffering from water: access to drinking-water and associated health risks in cameroon. | although many african countries, along the equator, receive a great amount of rainfall and possess a dense hydrographic network, access to drinking-water remains a great challenge. in many households, water is used for various purposes, including domestic and crafts activities. according to the world health organization, an estimated four billion cases of diarrheoa occurs worldwide, of which 88% are ascribed to unsafe drinking-water. this study aimed at evaluating health risks in the usage of co ... | 2010 | 20941893 |
| citrobacter freundii-induced cold agglutinin hemolysis. | 2010 | 20938661 | |
| silent mischief: bacteriophage mu insertions contaminate products of escherichia coli random mutagenesis performed using suicidal transposon delivery plasmids mobilized by broad-host-range rp4 conjugative machinery. | random transposon mutagenesis is the strategy of choice for associating a phenotype with its unknown genetic determinants. it is generally performed by mobilization of a conditionally replicating vector delivering transposons to recipient cells using broad-host-range rp4 conjugative machinery carried by the donor strain. in the present study, we demonstrate that bacteriophage mu, which was deliberately introduced during the original construction of the widely used donor strains sm10 λpir and s17 ... | 2010 | 20935093 |
| successful treatment of fusarium solani ecthyma gangrenosum in a patient affected by leukocyte adhesion deficiency type 1 with granulocytes transfusions. | ecthyma gangrenosum (eg) manifests as a skin lesion affecting patients suffering extreme neutropenia and is commonly associated with pseudomonas aeruginosa in immunocompromised patients. leukocyte adhesion deficiency i (lad i) which count among primary immunodeficiency syndromes of the innate immunity, is an autosomal recessive disorder characterized in its severe phenotype by a complete defect in cd18 expression on neutrophils, delayed cord separation, chronic skin ulcers mainly due to recurren ... | 2010 | 20929531 |
| alimentary tract bacteria isolated and identified with api-20e and molecular cloning techniques from australian tropical fruit flies, bactrocera cacuminata and b. tryoni. | bacteria were isolated from the crop and midgut of field collected bactrocera cacuminata (hering) and bactrocera tryoni (froggatt) (diptera: tephritidae). two methods were used, firstly isolation onto two types of bacteriological culture media (pyea and tsa) and identification using the api-20e diagnostic kit, and secondly, analysis of samples using the 16s rrna gene molecular diagnostic method. using the api-20e method, 10 genera and 17 species of bacteria in the family enterobacteriaceae were ... | 2010 | 20883132 |
| outbreak of meropenem-resistant serratia marcescens comediated by chromosomal ampc beta-lactamase overproduction and outer membrane protein loss. | the aim of this study was to investigate the mechanisms involved in the meropenem resistance of serratia marcescens clinical isolates. meropenem-resistant (mic range, 16 to 32 μg/ml) s. marcescens isolates were recovered from nine patients in a tertiary hospital in seoul, south korea, from june to november 2005. all the isolates shared identical or similar (>85% similarity) spei macrorestriction patterns, indicating clonal spread. pcr experiments did not detect any carbapenemase in those isolate ... | 2010 | 20876374 |
| isolation and characterization of bacteria from the gut of bombyx mori that degrade cellulose, xylan, pectin and starch and their impact on digestion. | bombyx mori l. (lepidoptera: bombycidae) have been domesticated and widely used for silk production. it feeds on mulberry leaves. mulberry leaves are mainly composed of pectin, xylan, cellulose and starch. some of the digestive enzymes that degrade these carbohydrates might be produced by gut bacteria. eleven isolates were obtained from the digestive tract of b. mori, including the gram positive bacillus circulans and gram negative proteus vulgaris, klebsiella pneumoniae, escherichia coli, citro ... | 2010 | 20874394 |
| structural insight into the mechanisms of transport across the salmonella enterica pdu microcompartment shell. | bacterial microcompartments are a functionally diverse group of proteinaceous organelles that confine specific reaction pathways in the cell within a thin protein-based shell. the propanediol utilizing (pdu) microcompartment contains the reactions for metabolizing 1,2-propanediol in certain enteric bacteria, including salmonella. the pdu shell is assembled from a few thousand protein subunits of several different types. here we report the crystal structures of two key shell proteins, pdua and pd ... | 2010 | 20870711 |
| predicting plasmid promiscuity based on genomic signature. | despite the important contribution of self-transmissible plasmids to bacterial evolution, little is understood about the range of hosts in which these plasmids have evolved. our goal was to infer this so-called evolutionary host range. the nucleotide composition, or genomic signature, of plasmids is often similar to that of the chromosome of their current host, suggesting that plasmids acquire their hosts' signature over time. therefore, we examined whether the evolutionary host range of plasmid ... | 2010 | 20851899 |
| detection of kpc-2-producing citrobacter freundii isolates in spain. | 2010 | 20851814 | |
| antibiotic susceptibility pattern in urinary isolates of gram negative bacilli with special reference to ampc β-lactamase in a tertiary care hospital. | resistance to higher antimicrobial agent is commonly seen in gram negative bacilli. this issue is a challenging problem to the medical practitioners in addition to it is financial impact on the health care system. | 2010 | 20842250 |
| aminoglycoside modifying enzymes. | aminoglycosides have been an essential component of the armamentarium in the treatment of life-threatening infections. unfortunately, their efficacy has been reduced by the surge and dissemination of resistance. in some cases the levels of resistance reached the point that rendered them virtually useless. among many known mechanisms of resistance to aminoglycosides, enzymatic modification is the most prevalent in the clinical setting. aminoglycoside modifying enzymes catalyze the modification at ... | 2010 | 20833577 |
| phytoremediation of mercury in pristine and crude oil contaminated soils: contributions of rhizobacteria and their host plants to mercury removal. | the rhizospheric soils of three tested legume crops: broad beans (vicia faba), beans (phaseolus vulgaris) and pea (pisum sativum), and two nonlegume crops: cucumber (cucumis sativus) and tomato, (lycopersicon esculentum) contained considerable numbers (the magnitude of 10(5)g(-1) soil) of bacteria with the combined potential for hydrocarbon-utilization and mercury-resistance. sequencing of the 16s rrna coding genes of rhizobacteria associated with broad beans revealed that they were affiliated t ... | 2010 | 20833430 |
| emergence of metallo-β-lactamase ndm-1-producing multidrug-resistant escherichia coli in australia. | a multidrug-resistant escherichia coli isolate recovered in australia produced a carbapenem-hydrolyzing β-lactamase. molecular investigations revealed the first identification of the bla(ndm-1) metallo-β-lactamase gene in that country. in addition, this e. coli isolate expressed the extended-spectrum β-lactamase ctx-m-15, together with two 16s rrna methylases, namely, arma and rmtb, conferring a high level of resistance to aminoglycosides. | 2010 | 20823289 |
| opportunistic bacterial infections in breeding colonies of the nsg mouse strain. | spontaneous morbidity primarily affecting female breeders in 3 independent breeding colonies of nsg (nod.cg-prkdc(scid) i12rg(tm1wjl) /szj) mice prompted an investigation to uncover the cause of disease. necropsies were performed on 264 (157 female and 107 male) spontaneously sick, experimentally unmanipulated nsg mice. in sum, 42 mice (15.9%) had acute or chronic renal inflammatory lesions, of which 12 had concurrent histologic evidence of an ascending urinary tract infection. from 94 kidneys c ... | 2011 | 20817888 |
| opportunistic bacterial infections in breeding colonies of the nsg mouse strain. | spontaneous morbidity primarily affecting female breeders in 3 independent breeding colonies of nsg (nod.cg-prkdc(scid) i12rg(tm1wjl) /szj) mice prompted an investigation to uncover the cause of disease. necropsies were performed on 264 (157 female and 107 male) spontaneously sick, experimentally unmanipulated nsg mice. in sum, 42 mice (15.9%) had acute or chronic renal inflammatory lesions, of which 12 had concurrent histologic evidence of an ascending urinary tract infection. from 94 kidneys c ... | 2011 | 20817888 |
| a conserved acetyl esterase domain targets diverse bacteriophages to the vi capsular receptor of salmonella enterica serovar typhi. | a number of bacteriophages have been identified that target the vi capsular antigen of salmonella enterica serovar typhi. here we show that these vi phages represent a remarkably diverse set of phages belonging to three phage families, including podoviridae and myoviridae. genome analysis facilitated the further classification of these phages and highlighted aspects of their independent evolution. significantly, a conserved protein domain carrying an acetyl esterase was found to be associated wi ... | 2010 | 20817773 |
| polymicrobial necrotizing fasciitis involving enterobacteria producing ctx-m-15 extended-spectrum β-lactamases. | necrotizing fasciitis due to multiple gram-negative organisms in a nigerian patient is described. morganella morganii and citrobacter freundii carrying the ctx-m-15 extended-spectrum β-lactamase gene were isolated, highlighting the emergence of this β-lactamase in western africa and its successful spread amongst a wider range of members of the enterobacteriaceae. | 2011 | 20813849 |
| enhanced determination of streptococcus pneumoniae serotypes associated with invasive disease in laos by using a real-time polymerase chain reaction serotyping assay with cerebrospinal fluid. | a prospective hospital-based study was undertaken to define the incidence of invasive pneumococcal disease (ipd) and circulating serotypes in laos. of 10,799 patients with hemocultures and 353 patients with cerebrospinal fluid samples, 0.21% and 5.4%, respectively, were positive for streptococcus pneumoniae, giving a total of 35 ipd patients. we developed a real-time polymerase chain reaction to detect serotypes represented in the 13-valent pneumococcal vaccine. a blinded evaluation comparing se ... | 2010 | 20810803 |
| the prevalence of bacterial contamination of surgical cold sterile solutions from community companion animal veterinary practices in southern ontario. | surgical cold sterile solutions are commonly used in veterinary practice, yet sterility cannot be verified under practical clinical conditions. surgical cold sterile solutions were sampled and bacteria, including opportunistic pathogens, were recovered from 13% of the sampled solutions. attempts to sterilize surgical instruments with cold sterile solutions should be avoided. | 2010 | 20808576 |
| origins and evolution of antibiotic resistance. | antibiotics have always been considered one of the wonder discoveries of the 20th century. this is true, but the real wonder is the rise of antibiotic resistance in hospitals, communities, and the environment concomitant with their use. the extraordinary genetic capacities of microbes have benefitted from man's overuse of antibiotics to exploit every source of resistance genes and every means of horizontal gene transmission to develop multiple mechanisms of resistance for each and every antibiot ... | 2010 | 20805405 |
| abc transporters involved in export of cell surface glycoconjugates. | complex glycoconjugates play critical roles in the biology of microorganisms. despite the remarkable diversity in glycan structures and the bacteria that produce them, conserved themes are evident in the biosynthesis-export pathways. one of the primary pathways involves representatives of the atp-binding cassette (abc) transporter superfamily. these proteins are responsible for the export of a wide variety of cell surface oligo- and polysaccharides in both gram-positive and gram-negative bacteri ... | 2010 | 20805402 |
| synthesis and spectrum of the neoglycoside achn-490. | achn-490 is a neoglycoside, or "next-generation" aminoglycoside (ag), that has been identified as a potentially useful agent to combat drug-resistant bacteria emerging in hospitals and health care facilities around the world. a focused medicinal chemistry campaign produced a collection of over 400 sisomicin analogs from which achn-490 was selected. we tested achn-490 against two panels of gram-negative and gram-positive pathogens, many of which harbored ag resistance mechanisms. unlike legacy ag ... | 2010 | 20805391 |
| sensitization of microcin j25-resistant strains by a membrane-permeabilizing peptide. | microcin j25 (mccj25) is a plasmid-encoded, 21-amino-acid, antibacterial peptide produced by escherichia coli. mccj25 inhibits rna polymerase and the membrane respiratory chain. mccj25 uptake into e. coli-sensitive strains is mediated by the outer membrane receptor fhua and the inner membrane proteins tonb, exbb, exbd, and sbma. this peptide is active on some e. coli, salmonella, and shigella species strains, while other gram-negative bacteria, such as clinical isolates of enterobacter cloacae, ... | 2010 | 20802073 |
| obstacles of multiplex real-time pcr for bacterial 16s rdna: primer specifity and dna decontamination of taq polymerase. | background: the detection of a broad range of bacteria by pcr is applied for the screening of blood and blood products with special attention to platelet concentrates. for practical use it is desirable that detection systems include gram-positive, gram-negative and non-gram-stainable bacteria. it is quite challenging to achieve high sensitivity along with a clear negative control with pcr reagents, because especially taq polymerase is contaminated with traces of bacterial dna. methods: bacterial ... | 2010 | 20737013 |
| phenotypic and biochemical comparison of the carbapenem-hydrolyzing activities of five plasmid-borne ampc β-lactamases. | the cmy-2, act-1, dha-1, acc-1, and fox-1 enzymes are representative of five plasmid-mediated ampc (pampc) β-lactamase clusters. resistance to imipenem has been reported in enterobacteriaceae as a result of pampc expression combined with decreased outer membrane permeability. the aim of this study was to determine the role of different pampcs in carbapenem resistance and to define the structure/activity relationship supporting carbapenemase activity. the ampc genes encoding the five pampcs and t ... | 2010 | 20733047 |
| glycan analysis and influenza a virus infection of primary swine respiratory epithelial cells: the importance of neuac{alpha}2-6 glycans. | to better understand influenza virus infection of pigs, we examined primary swine respiratory epithelial cells (srecs, the primary target cells of influenza viruses in vivo), as a model system. glycomic profiling of srecs by mass spectrometry revealed a diverse range of glycans terminating in sialic acid or galαgal. in terms of sialylation, α2-6 linkage was more abundant than α2-3, and neuac was more abundant than neugc. virus binding and infection experiments were conducted to determine functio ... | 2010 | 20724471 |
| faecal carriage of extended-spectrum β-lactamase-producing and ampc β-lactamase-producing bacteria among danish army recruits. | during may and june 2008, 84 danish army recruits were tested for faecal carriage of extended-spectrum β-lactamase (esbl)-producing and ampc β-lactamase-producing bacteria. three esbl-producing (ctx-m-14a) escherichia coli isolates, two ampc-producing (cmy-2) e. coli isolates and one ampc-producing (cmy-34) citrobacter freundii isolate were detected. two of the ctx-m-14a e. coli isolates had similar pulsed-field gel electrophoresis and multilocus sequence typing profiles, indicating the same ori ... | 2011 | 20718802 |
| ampg gene of pseudomonas aeruginosa and its role in β-lactamase expression. | in enterobacteria, the ampg gene encodes a transmembrane protein (permease) that transports 1,6-glcnac-anhydro-murnac and the 1,6-glcnac-anhydro-murnac peptide from the periplasm to the cytoplasm, which serve as signal molecules for the induction of ampc β-lactamase. the role of ampg as a transporter is also essential for cell wall recycling. pseudomonas aeruginosa carries two ampg homologues, ampg (pa4393) and ampgh1 (pa4218), with 45 and 41% amino acid sequence identity, respectively, to esche ... | 2010 | 20713660 |
| emergence of a new antibiotic resistance mechanism in india, pakistan, and the uk: a molecular, biological, and epidemiological study. | gram-negative enterobacteriaceae with resistance to carbapenem conferred by new delhi metallo-beta-lactamase 1 (ndm-1) are potentially a major global health problem. we investigated the prevalence of ndm-1, in multidrug-resistant enterobacteriaceae in india, pakistan, and the uk. | 2010 | 20705517 |
| prevalence of antimicrobial resistance among gram-negative isolates in an adult intensive care unit at a tertiary care center in saudi arabia. | patients in the icu have encountered an increasing emergence and spread of antibiotic-resistant pathogens. we examined patterns of antimicrobial susceptibility in gram-negative isolates to commonly used drugs in an adult icu at a tertiary care hospital in riyadh, saudi arabia. | 2010 | 20697174 |
| mutations of francisella novicida that alter the mechanism of its phagocytosis by murine macrophages. | infection with the bacterial pathogen francisella tularensis tularensis (f. tularensis) causes tularemia, a serious and debilitating disease. francisella tularensis novicida strain u112 (abbreviated f. novicida), which is closely related to f. tularensis, is pathogenic for mice but not for man, making it an ideal model system for tularemia. intracellular pathogens like francisella inhibit the innate immune response, thereby avoiding immune recognition and death of the infected cell. because acti ... | 2010 | 20686600 |
| biochip system for rapid and accurate identification of mycobacterial species from isolates and sputum. | the accurate detection of mycobacterial species from isolates and clinical samples is important for pathogenic diagnosis and treatment and for disease control. there is an urgent need for the development of a rapid, simple, and accurate detection method. we established a biochip assay system, including a biochip, sample preparation apparatus, hybridization instrument, chip washing machine, and laser confocal scanner equipped with interpretation software for automatic diagnosis. the biochip simul ... | 2010 | 20686082 |
| qnrb9 in association with tem-116 extended-spectrum beta-lactamase in citrobacter freundii isolated from sewage effluent: first report from italy. | the aim of the present study was to investigate the mechanism of quinolone and beta-lactam resistance in an isolate of citrobacter freundii pc2/08 collected from sewage effluent from l'aquila, italy. qnrb-9 and bla(tem-116 )were co-expressed in a large plasmid identified in c. freundi pc2/08 strain. compared to tem-1, tem-116 showed two single mutations: v84i and a184v. the plpc2/08 plasmid conferred resistance to several beta-lactams and fluoroquinolones. tazobactam could be considered a good i ... | 2010 | 20685627 |
| evidence for a bimodal distribution of escherichia coli doubling times below a threshold initial cell concentration. | in the process of developing a microplate-based growth assay, we discovered that our test organism, a native e. coli isolate, displayed very uniform doubling times (tau) only up to a certain threshold cell density. below this cell concentration (<or= 100 -1,000 cfu ml-1 ; <or= 27-270 cfu well-1) we observed an obvious increase in the tau scatter. | 2010 | 20678197 |
| characterization of the pdus cobalamin reductase of salmonella enterica and its role in the pdu microcompartment. | salmonella enterica degrades 1,2-propanediol (1,2-pd) in a coenzyme b12 (adenosylcobalamin, adocbl)-dependent fashion. salmonella obtains adocbl by assimilation of complex precursors, such as vitamin b12 and hydroxocobalamin. assimilation of these compounds requires reduction of their central cobalt atom from co3+ to co2+ to co+, followed by adenosylation to adocbl. in this work, the his6-tagged pdus cobalamin reductase from s. enterica was produced at high levels in escherichia coli, purified, ... | 2010 | 20656910 |
| antioxidant, antimicrobial activity and toxicity test of pilea microphylla. | a total of 9 plant extracts were tested, using two different kinds of extracting methods to evaluate the antioxidant and antimicrobial activities from pilea microphylla (urticaceae family) and including toxicity test. antioxidant activity were tested by using dpph free radical scavenging, also total phenolic contents and total flavonoid contents were determined. toxicity assay carried out by using brine shrimps. methanol extract of method i (me i) showed the highest antioxidant activity at 69.51 ... | 2010 | 20652052 |
| survival of campylobacter jejuni under conditions of atmospheric oxygen tension with the support of pseudomonas spp. | campylobacter jejuni is a major food-borne pathogen. despite causing enteritis in humans, it is a well-adapted intestinal microorganism in animals, hardly ever generating disease symptoms. nevertheless, as a true microaerophilic microorganism it is still puzzling how campylobacter cells can survive on chicken meat, the main source of human infection. in this study, we demonstrate that c. jejuni is able to withstand conditions of atmospheric oxygen tension when cocultured with pseudomonas species ... | 2010 | 20639377 |
| molecular characteristics of extended spectrum beta-lactamases in escherichia coli and klebsiella pneumoniae and the prevalence of qnr in extended spectrum beta-lactamase isolates in a tertiary care hospital in korea. | extended spectrum beta-lactamases (esbls) are cephalosporinases that confer resistance to a wide variety of oxyimino cephalosporins and create serious therapeutic problems. in addition, the quinolone resistance qnr genes are becoming increasingly prevalent in clinical isolates, some of which also produce esbl. this study was designed to evaluate the occurrence and genotypic distribution of esbl producing escherichia coli (e. coli) and klebsiella pneumoniae (k. pneumoniae) as well as the prevalen ... | 2010 | 20635454 |
| rapid identification of bacterial pathogens in positive blood culture bottles by use of a broad-based pcr assay coupled with high-resolution melt analysis. | we evaluated a broad-based pcr assay coupled with high-resolution melt analysis for rapid bacterial identification in patients with bacterial sepsis. with a reference library of 60 clinically relevant bacterial species, 52 positive blood culture samples were tested. our assay identified 46/52 samples at the species level, with 100% concordance to culture findings. | 2010 | 20631110 |
| laboratory surveillance for prospective plasmid-mediated ampc beta-lactamases in the kinki region of japan. | extended-spectrum beta-lactamases, plasmid-mediated ampc beta-lactamases (pabls), and plasmid-mediated metallo-beta-lactamases confer resistance to many beta-lactams. in japan, although several reports exist on the prevalence of extended-spectrum beta-lactamases and metallo-beta-lactamases, the prevalence and characteristics of pabls remain unknown. to investigate the production of pabls, a total of 22,869 strains of 4 enterobacterial species, escherichia coli, klebsiella pneumoniae, klebsiella ... | 2010 | 20610688 |
| exploring methionine γ-lyase structure-function relationship via microspectrophotometry and x-ray crystallography. | pyridoxal 5'-phosphate (plp) dependent methionine γ-lyase catalyzes the breakdown of l-methionine to α-ketobutyric acid, methanethiol and ammonia. this enzyme, present in anaerobic microorganisms, has biomedical interest both for its activity as antitumor agent, depleting methionine supply in methionine-dependent cancers, and as target in the treatment of human pathogen infections, activating the pro-drug trifluoromethionine. to validate the structure of the enzyme from citrobacter freundii, cry ... | 2011 | 20601224 |
| rapid and sensitive detection of yersinia pestis using amplification of plague diagnostic bacteriophages monitored by real-time pcr. | yersinia pestis, the agent of plague, has caused many millions of human deaths and still poses a serious threat to global public health. timely and reliable detection of such a dangerous pathogen is of critical importance. lysis by specific bacteriophages remains an essential method of y. pestis detection and plague diagnostics. | 2010 | 20596528 |
| crystal structure of the ampr effector binding domain provides insight into the molecular regulation of inducible ampc beta-lactamase. | hyperproduction of ampc beta-lactamase (ampc) is a formidable mechanism of resistance to penicillins and cephalosporins in gram-negative bacteria such as pseudomonas aeruginosa and enterobacteriaceae. ampc expression is regulated by the lysr-type transcriptional regulator ampr. ampr and ampc genes form a divergent operon with overlapping promoters to which ampr binds and regulates the transcription of both genes. ampr induces ampc by binding to one member of the family of 1,6-anhydro-n-acetylmur ... | 2010 | 20594961 |
| bench-to-bedside review: the role of beta-lactamases in antibiotic-resistant gram-negative infections. | multidrug resistance has been increasing among gram-negative bacteria and is strongly associated with the production of both chromosomal- and plasmid-encoded beta-lactamases, whose number now exceeds 890. many of the newer enzymes exhibit broad-spectrum hydrolytic activity against most classes of beta-lactams. the most important plasmid-encoded beta-lactamases include (a) ampc cephalosporinases produced in high quantities, (b) the expanding families of extended-spectrum beta-lactamases such as t ... | 2010 | 20594363 |
| insufficient β-lactam concentrations in the early phase of severe sepsis and septic shock. | altered pharmacokinetics (pk) in critically ill patients can result in insufficient serum β-lactam concentrations when standard dosages are administered. previous studies on β-lactam pk have generally excluded the most severely ill patients, or were conducted during the steady-state period of treatment. the aim of our study was to determine whether the first dose of piperacillin-tazobactam, ceftazidime, cefepime, and meropenem would result in adequate serum drug concentrations in patients with s ... | 2010 | 20594297 |
| bloodstream infections and clinical significance of healthcare-associated bacteremia: a multicenter surveillance study in korean hospitals. | recent changes in healthcare systems have changed the epidemiologic paradigms in many infectious fields including bloodstream infection (bsi). we compared clinical characteristics of community-acquired (ca), hospital-acquired (ha), and healthcare-associated (hca) bsi. we performed a prospective nationwide multicenter surveillance study from 9 university hospitals in korea. total 1,605 blood isolates were collected from 2006 to 2007, and 1,144 isolates were considered true pathogens. ha-bsi accou ... | 2010 | 20592888 |
| screening of urine samples by flow cytometry reduces the need for culture. | urine samples constitute a large proportion of samples tested in clinical microbiology laboratories. culturing of the samples is fairly time- and labor-consuming, and most of the samples will yield no growth or insignificant growth. we analyzed the feasibility of the flow cytometry-based uf-500i instrument (sysmex, japan) to screen out urine samples with no growth or insignificant growth and reduce the number of samples to be cultured. a total of 1,094 urine specimens sent to our laboratory for ... | 2010 | 20592157 |
| comparison of broth microdilution, agar dilution, and etest for susceptibility testing of doripenem against gram-negative and gram-positive pathogens. | the susceptibility of 513 clinical isolates to doripenem was determined by broth microdilution, agar dilution, and etest. overall agreements for etest and agar dilution mic values compared to reference broth microdilution at +/-1 log(2) dilution were 88% and 94%, respectively. etest mic values demonstrated 98% agreement within +/-2 log(2) dilutions compared to the reference broth microdilution method. | 2010 | 20592149 |
| detection of human intestinal catalase-negative, gram-positive cocci by rrna-targeted reverse transcription-pcr. | an analytical system based on rrna-targeted reverse transcription-quantitative pcr (rt-qpcr) for enumeration of catalase-negative, gram-positive cocci was established. subgroup- or species-specific primer sets targeting 16s or 23s rrna from enterococcus, streptococcus, and lactococcus were newly developed. the rt-qpcr method using these primers together with the previously reported primer sets specific for the enterococcus genus, the streptococcus genus, and several streptococcus species was fou ... | 2010 | 20581195 |
| risk factors for acute prostatitis after transrectal biopsy of the prostate. | to investigate the incidence, clinical features, pathogenic bacteria, and risk factors associated with acute prostatitis after transrectal prostate biopsy. | 2010 | 20577611 |
| molecular analysis of type 3 fimbrial genes from escherichia coli, klebsiella and citrobacter species. | catheter-associated urinary tract infection (cauti) is the most common nosocomial infection in the united states and is caused by a range of uropathogens. biofilm formation by uropathogens that cause cauti is often mediated by cell surface structures such as fimbriae. in this study, we characterised the genes encoding type 3 fimbriae from cauti strains of escherichia coli, klebsiella pneumoniae, klebsiella oxytoca, citrobacter koseri and citrobacter freundii. | 2010 | 20576143 |
| chromosomally encoded blacmy-2 located on a novel sxt/r391-related integrating conjugative element in a proteus mirabilis clinical isolate. | integrating conjugative elements (ices) are mobile genetic elements that can transfer from the chromosome of a host to the chromosome of a new host through the process of excision, conjugation, and integration. although sxt/r391-related ices, originally demonstrated in vibrio cholerae o139 isolates, have become prevalent among v. cholerae isolates in asia, the prevalence of the ices among gram-negative bacteria other than vibrio spp. remains unknown. in addition, sxt/r391-related ices carrying g ... | 2010 | 20566768 |
| nagz inactivation prevents and reverts beta-lactam resistance, driven by ampd and pbp 4 mutations, in pseudomonas aeruginosa. | ampc hyperproduction is the most frequent mechanism of resistance to penicillins and cephalosporins in pseudomonas aeruginosa and is driven by ampd mutations or the recently described inactivation of dacb, which encodes the nonessential penicillin-binding protein (pbp) pbp 4. recent work showed that nagz inactivation attenuates beta-lactam resistance in ampd mutants. here we explored whether the same could be true for the dacb mutants with dacb mutations alone or in combination with ampd mutatio ... | 2010 | 20566764 |
| impact of long-term wastewater application on microbiological properties of vadose zone. | impact of wastewater irrigation on some biological properties was studied in an area where treated sewage water is being supplied to the farmers since 1979 in the western part of national capital territory of new delhi under keshopur effluent irrigation scheme. three fields were selected which had been receiving irrigation through wastewater for last 20, 10 and 5 years. two additional fields were selected in which the source of irrigation water was tubewell. the soil bacterial and fungal populat ... | 2011 | 20559712 |
| high level expression of an acid-stable phytase from citrobacter freundii in pichia pastoris. | to obtain a high level expression of phytase with favorable characteristics, a codon-optimized phytase gene from citrobacter freundii was synthesized and transferred into pichia pastoris. small-scale expression experiments and activity assays were used to screen positive colonies. after purified by ni²+-nta agarose affinity column, the characterizations of the recombinant phytase were determined. the recombinant phytase (r-phyc) had two distinct ph optima at 2.5 and 4.5 and an optimal temperatur ... | 2010 | 20556542 |
| [detection of bla(ctx-m) beta-lactamase genes in extended-spectrum beta-lactamase producing gram-negative bacteria]. | widespread production of ctx-m type extended-spectrum beta-lactamases (esbl) in enterobacteriaceae strains which are resistant to extended-spectrum cephalosporins is the most remarkable example for rapid and global spread of plasmid mediated antimicrobial resistance in bacteria. consecutive 200 esbl producing enterobacteriaceae strains out of 1640 isolates that were obtained from clinical samples (167 urine, 11 wound, 7 bronchoalveolar lavage, 3 peritoneal fluid, 2 cerebrospinal fluid, 2 biopsy, ... | 2010 | 20549952 |
| resistance to cephalosporins and carbapenems in gram-negative bacterial pathogens. | during the past 15 years, emergence and dissemination of beta-lactam resistance in nosocomial enterobacteriaceae, pseudomonas aeruginosa and acinetobacter baumannii, became a serious problem worldwide. especially the increasing resistance to 3rd and 4th generation cephalosporins and carbapenems is of particular concern. gram-negative bacteria pursue various molecular strategies for development of resistance to these antibiotics: (a) generation of extended-spectrum beta-lactamases (esbl) accordin ... | 2010 | 20537585 |
| comparison of bd phoenix, vitek 2, and microscan automated systems for detection and inference of mechanisms responsible for carbapenem resistance in enterobacteriaceae. | we assessed the ability of three commercial systems to infer carbapenem resistance mechanisms in 39 carbapenemase-producing and 16 other carbapenem-resistant enterobacteriaceae. the sensitivity/specificity values for "flagging" a likely carbapenemase were 100%/0% (bd phoenix), 82 to 85%/6 to 19% (microscan), and 74%/38% (vitek 2), respectively. oxa-48 producers were poorly detected, but all systems reliably detected isolates with kpc and most with metallo-carbapenemases. | 2010 | 20534805 |