| acanthamoeba castellanii promotes the survival of vibrio parahaemolyticus. | vibrio parahaemolyticus is a food-borne pathogen that naturally inhabits both marine and estuarine environments. free-living protozoa exist in similar aquatic environments and function to control bacterial numbers by grazing on free-living bacteria. protozoa also play an important role in the survival and spread of some pathogenic species of bacteria. we investigated the interaction between the protozoan acanthamoeba castellanii and the bacterium vibrio parahaemolyticus. we found that acanthamoe ... | 2008 | 18849458 |
| crystal structure of escherichia coli mazg, the regulator of nutritional stress response. | mazg is a nucleoside triphosphate pyrophosphohydrolase that hydrolyzes all canonical nucleoside triphosphates. the mazg gene located downstream from the chromosomal mazef "addiction module," that mediated programmed cell death in escherichia coli. mazg activity is inhibited by the mazef complex both in vivo and in vitro. enzymatic activity of mazg in vivo affects the cellular level of guanosine 3',5'-bispyrophosphate (ppgpp), synthesized by rela under amino acid starvation. the reduction of ppgp ... | 2008 | 18353782 |
| chromobacterium aquaticum sp. nov., isolated from spring water samples. | strain cc-seya-1t, a motile, gram-negative, non-violet-pigmented bacterium, was isolated on nutrient agar from spring-water samples collected from yang-ming mountain, taipei county, taiwan. 16s rrna gene sequence studies showed that the strain clustered with chromobacterium violaceum (96.8 % similarity) and chromobacterium subtsugae (96.5 % similarity), followed by aquitalea magnusonii (95.8 % similarity). the fatty acid profile was slightly different from those reported for c. violaceum, c. sub ... | 2008 | 18398186 |
| degradation of n-acyl homoserine lactone quorum sensing signal molecules by forest root-associated fungi. | a collection of mycorrhizal and nonmycorrhizal root-associated fungi coming from forest environments was screened for their ability to degrade n-acyl homoserine lactones (ahl) or to prevent ahl recognition by producing quorum sensing inhibitors (qsi). no production of qs-inhibitors or -activators was detected using the two biosensors chromobacterium violaceum cv026 and agrobacterium tumefaciens in the culture supernatant of these fungi. however, the ability to degrade c6- and 3o,c6-hsl was detec ... | 2008 | 18400006 |
| ppsy: a vector for the stable cloning and expression of streptomycete single gene phenotypes in escherichia coli. | ppsy is a 12kb cloning vector derived from the incw plasmid r388, which provides a rapid and easy way to stably clone phenotypes encoded in dna segments <10kb. in the present study three different genes were amplified by pcr, cloned into pgem-t easy and sub-cloned into the ecori site of ppsy. the first gene, vioa, is a fad-dependent l-tryptophan amino acid oxygenase from the high g+c gram-negative bacterium chromobacterium violaceum. vioa is involved in the synthesis of the indolocarbazole antit ... | 2008 | 18406459 |
| kinetics of thermal unfolding of phenylalanine hydroxylase variants containing different metal cofactors (feii, coii, and znii) and their isokinetic relationship. | the kinetics of thermal unfolding of apo- and holo-chromobacterium violaceum phenylalanine hydroxylase (cpah) was investigated using circular dichroism (cd) over the temperature range 44-76 degrees c. in addition to the native cofactor (feii), the unfolding kinetics of holo-cpah was characterized using znii and coii as cofactors. kinetic profiles for apo- and holo-cpah showed a single-phase exponential rise in the cd signal at lambda=222 nm and a first-order dependence on protein concentration. ... | 2008 | 18433092 |
| anthranilate synthase subunit organization in chromobacterium violaceum. | tryptophan is an aromatic amino acid used for protein synthesis and cellular growth. chromobacterium violaceum atcc 12472 uses two tryptophan molecules to synthesize violacein, a secondary metabolite of pharmacological interest. the genome analysis of this bacterium revealed that the genes trpa-f and paba-b encode the enzymes of the tryptophan pathway in which the first reaction is the conversion of chorismate to anthranilate by anthranilate synthase (as), an enzyme complex. in the present study ... | 2008 | 18949702 |
| using mahalanobis distance to compare genomic signatures between bacterial plasmids and chromosomes. | plasmids are ubiquitous mobile elements that serve as a pool of many host beneficial traits such as antibiotic resistance in bacterial communities. to understand the importance of plasmids in horizontal gene transfer, we need to gain insight into the 'evolutionary history' of these plasmids, i.e. the range of hosts in which they have evolved. since extensive data support the proposal that foreign dna acquires the host's nucleotide composition during long-term residence, comparison of nucleotide ... | 2008 | 18953039 |
| quorum sensing primes the oxidative stress response in the insect endosymbiont, sodalis glossinidius. | sodalis glossinidius, a maternally transmitted bacterial endosymbiont of tsetse flies (glossina spp.), uses an acylated homoserine lactone (ahl)-based quorum sensing system to modulate gene expression in accordance with bacterial cell density. the s. glossinidius quorum sensing system relies on the function of two regulatory proteins; sogi (a luxi homolog) synthesizes a signaling molecule, characterized as n-(3-oxohexanoyl) homoserine lactone (ohhl), and sogr1 (a luxr homolog) interacts with ohh ... | 2008 | 18958153 |
| microbial iron management mechanisms in extremely acidic environments: comparative genomics evidence for diversity and versatility. | iron is an essential nutrient but can be toxic at high intracellular concentrations and organisms have evolved tightly regulated mechanisms for iron uptake and homeostasis. information on iron management mechanisms is available for organisms living at circumneutral ph. however, very little is known about how acidophilic bacteria, especially those used for industrial copper bioleaching, cope with environmental iron loads that can be 1018 times the concentration found in ph neutral environments. t ... | 2008 | 19025650 |
| chromobacterium haemolyticum sp. nov., a strongly haemolytic species. | a gram-negative bacterium, strain mda0585(t), isolated from a sputum culture, was characterized by a polyphasic approach. the 16s rrna gene and a conserved portion of the dna gyrase a gene were sequenced and analysed phylogenetically. strain mda0585(t) showed the closest relationships with chromobacterium violaceum atcc 12472(t) and chromobacterium subtsugae praa4-1(t) (96.1 % and 96.3 % 16s rrna gene sequence similarity, respectively). the cellular fatty acids of strain mda0585(t) consisted mai ... | 2008 | 18523185 |
| analysis of the genome sequence of lactobacillus gasseri atcc 33323 reveals the molecular basis of an autochthonous intestinal organism. | this study presents the complete genome sequence of lactobacillus gasseri atcc 33323, a neotype strain of human origin and a native species found commonly in the gastrointestinal tracts of neonates and adults. the plasmid-free genome was 1,894,360 bp in size and predicted to encode 1,810 genes. the gc content was 35.3%, similar to the gc content of its closest relatives, l. johnsonii ncc 533 (34%) and l. acidophilus ncfm (34%). two identical copies of the prophage lgai (40,086 bp), of the sfi11- ... | 2008 | 18539810 |
| diversity of chromobacterium violaceum isolates from aquatic environments of state of pará, brazilian amazon. | the present study intended to characterize the phenotypic and genetic diversity of brazilian isolates of chromobacterium violaceum from aquatic environments within the amazon region. nineteen isolates showed morphological properties of c. violaceum and the majority grew at 44 degrees c. low temperatures, in contrast, showed to be inhibitory to their growth, as eleven isolates did not grow at 10 degrees c and nine did not produce pigmentation, clearly indicating an inhibition of their metabolism. ... | 2008 | 19057818 |
| improved prediction of malaria degradomes by supervised learning with svm and profile kernel. | the spread of drug resistance through malaria parasite populations calls for the development of new therapeutic strategies. however, the seemingly promising genomics-driven target identification paradigm is hampered by the weak annotation coverage. to identify potentially important yet uncharacterized proteins, we apply support vector machines using profile kernels, a supervised discriminative machine learning technique for remote homology detection, as a complement to the traditional alignment ... | 2009 | 19057851 |
| improved prediction of malaria degradomes by supervised learning with svm and profile kernel. | the spread of drug resistance through malaria parasite populations calls for the development of new therapeutic strategies. however, the seemingly promising genomics-driven target identification paradigm is hampered by the weak annotation coverage. to identify potentially important yet uncharacterized proteins, we apply support vector machines using profile kernels, a supervised discriminative machine learning technique for remote homology detection, as a complement to the traditional alignment ... | 2009 | 19057851 |
| human chromobacterium violaceum infection in southeast asia: case reports and literature review. | chromobacterium violaceum infection in humans is a rare tropical and subtropical disease. the awareness of this organism is limited in spite its ubiquitous distribution. several cases have been reported from southeast asia. a localized infection followed by an overwhelming septicemia and metastatic lesions is the usual pattern of this illness. optimal antimicrobial treatment and duration are unknown. consequently, the outcome is usually fatal. the study reported two patients who suffered from fu ... | 2008 | 18564684 |
| septicemia in a neonatal calf associated with chromobacterium violaceum. | chromobacterium violaceum infections are highly fatal and rarely reported in domestic animals. this report describes a fatal case of c. violaceum septicemia in a 7-day-old female beef calf. the calf had necrosuppurative omphalophlebitis, necrotizing interstitial pneumonia, necrosuppurative hepatitis and splenitis, anterior uveitis with hypopyon, suppurative polyarthritis, and disseminated hemorrhagic meningitis with multifocal necrotizing encephalitis. histologically, clusters of gram-negative b ... | 2009 | 19112118 |
| a fatal case of chromobacterium violaceum septicemia in hong kong. | chromobacterium violaceum causes a rare infection in human, usually in tropical or subtropical areas. we report a fatal case of c. violaceum infection affecting a 40-year-old previously healthy man in hong kong. he presented with a wound infection and lymphadenitis. despite multiple antibiotic treatment, including ciprofloxacin, he succumbed shortly after admission to the hospital. we report the epidemiological investigation findings and discuss the possible sources of infection. physicians shou ... | 2006 | 17333774 |
| chlamydia pneumoniae encodes a functional aromatic amino acid hydroxylase. | chlamydia pneumoniae is a community-acquired respiratory pathogen that has been associated with the development of atherosclerosis. analysis of the c. pneumoniae genome identified a gene (cpn1046) homologous to eukaryotic aromatic amino acid hydroxylases (aroaa-hs). aroaa-hs hydroxylate phenylalanine, tyrosine, and tryptophan into tyrosine, dihydroxyphenylalanine, and 5-hydroxytryptophan, respectively. sequence analysis of cpn1046 demonstrated that residues essential for aroaa-h enzymatic functi ... | 2009 | 19141112 |
| the effect of quorum-sensing blockers on the formation of marine microbial communities and larval attachment. | we studied the effect of the quorum-sensing (qs) blockers 5-hydroxy-3[(1r)-1-hydroxypropyl]-4-methylfuran-2(5h)-one (fur1), (5r)-3,4-dihydroxy-5-[(1s)-1,2-dihydroxyethyl]furan-2(5h)-one (fur2) and triclosan (tri) on the formation of bacterial biofilms, and the effect of these biofilms on the larval attachment of the polychaete hydroides elegans and the bryozoan bugula neritina. 14-day-old subtidal biofilms were harvested from artificial substrata and were allowed to develop in the laboratory wit ... | 2007 | 17371321 |
| characterization of a gene cluster responsible for the biosynthesis of anticancer agent fk228 in chromobacterium violaceum no. 968. | a gene cluster responsible for the biosynthesis of anticancer agent fk228 has been identified, cloned, and partially characterized in chromobacterium violaceum no. 968. first, a genome-scanning approach was applied to identify three distinctive c. violaceum no. 968 genomic dna clones that code for portions of nonribosomal peptide synthetase and polyketide synthase. next, a gene replacement system developed originally for pseudomonas aeruginosa was adapted to inactivate the genomic dna-associated ... | 2007 | 17400765 |
| synthesis and conformation-activity relationships of the peptide isosteres of fk228 and largazole. | the peptide isosteres (10 and 11) of the naturally occurring and potent histone deacetylase (hdac) inhibitors fk228 and largazole have been synthesized and evaluated side-by-side with fk228, largazole, and saha for inhibition of the class i hdacs 1, 2, 3, and 6. | 2009 | 19193120 |
| species distribution and antimicrobial susceptibility of gram-negative aerobic bacteria in hospitalized cancer patients. | nosocomial infections pose significant threats to hospitalized patients, especially the immunocompromised ones, such as cancer patients. | 2009 | 19228413 |
| chromobacterium subtsugae sp. nov., a betaproteobacterium toxic to colorado potato beetle and other insect pests. | strain praa4-1(t), a motile, gram-negative, violet-pigmented bacterium, was isolated from maryland forest soil and found to be orally toxic to colorado potato beetle larvae and other insects. morphological, biological, biochemical and molecular characterization revealed that this strain was most similar to chromobacterium violaceum, the type species and only currently recognized member of the genus chromobacterium. dna-dna hybridization with c. violaceum atcc 12472(t) was 27 %. phylogenetic anal ... | 2007 | 17473247 |
| gulbenkiania mobilis gen. nov., sp. nov., isolated from treated municipal wastewater. | a bacterial strain (e4fc31(t)) isolated from treated municipal wastewater was characterized phenotypically and phylogenetically. cells were gram-negative, curved rods with a polar flagellum. the isolate was catalase-, oxidase- and arginine dihydrolase-positive, and able to grow between 15 and 45 degrees c and between ph 5.5 and 9.0. the predominant fatty acids were c(16 : 1)/iso-c(15 : 0) 2-oh and c(16 : 0), the major respiratory quinone was ubiquinone 8 and the g+c content of the genomic dna wa ... | 2007 | 17473267 |
| the cin and rai quorum-sensing regulatory systems in rhizobium leguminosarum are coordinated by expr and cins, a small regulatory protein coexpressed with cini. | to understand how the rhizobium leguminosarum raii-rair quorum-sensing system is regulated, we identified mutants with decreased levels of raii-made n-acyl homoserine lactones (ahls). a luxr-type regulator, expr, is required for rair expression, and rair is required to induce raii. since rair (and raii) expression is also reduced in cini and cinr quorum-sensing mutants, we thought cini-made ahls may activate expr to induce rair. however, added cini-made ahls did not induce rair expression in a c ... | 2009 | 19270098 |
| eukaryotic nirk genes encoding copper-containing nitrite reductase: originating from the protomitochondrion? | although denitrification or nitrate respiration has been found among a few eukaryotes, its phylogenetic relationship with the bacterial system remains unclear because orthologous genes involved in the bacterial denitrification system were not identified in these eukaryotes. in this study, we isolated a gene from the denitrifying fungus fusarium oxysporum that is homologous to the bacterial nirk gene responsible for encoding copper-containing nitrite reductase (nirk). characterization of the gene ... | 2009 | 19270125 |
| violacein extracted from chromobacterium violaceum inhibits plasmodium growth in vitro and in vivo. | violacein is a violet pigment extracted from the gram-negative bacterium chromobacterium violaceum. it presents bactericidal, tumoricidal, trypanocidal, and antileishmanial activities. we show that micromolar concentrations efficiently killed chloroquine-sensitive and -resistant plasmodium falciparum strains in vitro; inhibited parasitemia in vivo, even after parasite establishment; and protected plasmodium chabaudi chabaudi-infected mice from a lethal challenge. | 2009 | 19273690 |
| comparison of routine bench and molecular diagnostic methods in identification of burkholderia pseudomallei. | this study compared the identification of burkholderia pseudomallei with that of related organisms. bench tests and latex agglutination were compared with molecular identification. using bench tests and latex agglutination alone, 100% (30/30) of b. pseudomallei isolates were correctly identified. amoxicillin-clavulanate susceptibility testing was also a good and simple discriminatory test. | 2009 | 19279182 |
| the complete genome and proteome of laribacter hongkongensis reveal potential mechanisms for adaptations to different temperatures and habitats. | laribacter hongkongensis is a newly discovered gram-negative bacillus of the neisseriaceae family associated with freshwater fish-borne gastroenteritis and traveler's diarrhea. the complete genome sequence of l. hongkongensis hlhk9, recovered from an immunocompetent patient with severe gastroenteritis, consists of a 3,169-kb chromosome with g+c content of 62.35%. genome analysis reveals different mechanisms potentially important for its adaptation to diverse habitats of human and freshwater fish ... | 2009 | 19283063 |
| globins synthesize the second messenger bis-(3'-5')-cyclic diguanosine monophosphate in bacteria. | globin-coupled sensors are heme-binding signal transducers in bacteria and archaea in which an n-terminal globin controls the activity of a variable c-terminal domain. here, we report that bpegreg, a globin-coupled diguanylate cyclase from the whooping cough pathogen bordetella pertussis, synthesizes the second messenger bis-(3'-5')-cyclic diguanosine monophosphate (c-di-gmp) upon oxygen binding. expression of bpegreg in salmonella typhimurium enhances biofilm formation, while knockout of the bp ... | 2009 | 19285985 |
| characterization of a new plasmid-like prophage in a pandemic vibrio parahaemolyticus o3:k6 strain. | vibrio parahaemolyticus is a common food-borne pathogen that is normally associated with seafood. in 1996, a pandemic o3:k6 strain abruptly appeared and caused the first pandemic of this pathogen to spread throughout many asian countries, america, europe, and africa. the role of temperate bacteriophages in the evolution of this pathogen is of great interest. in this work, a new temperate phage, vp882, from a pandemic o3:k6 strain of v. parahaemolyticus was purified and characterized after mitomy ... | 2009 | 19286788 |
| pqsa is required for the biosynthesis of 2,4-dihydroxyquinoline (dhq), a newly identified metabolite produced by pseudomonas aeruginosa and burkholderia thailandensis. | a new metabolite, 2,4-dihydroxyquinoline (dhq), was identified in cultures of the bacteria pseudomonas aeruginosa and burkholderia thailandensis. we found that the biosynthesis of dhq correlates with the presence of a functional pqsa, which is a product of the pqsabcde operon responsible for the synthesis of 4-hydroxy-2-alkylquinolines (haqs) in p. aeruginosa. however, dhq is not a degradation product or precursor of haqs. this finding sheds some light on the poorly understood biosynthesis pathw ... | 2007 | 17655503 |
| the plant pathogen pantoea ananatis produces n-acylhomoserine lactone and causes center rot disease of onion by quorum sensing. | a number of gram-negative bacteria have a quorum-sensing system and produce n-acyl-l-homoserine lactone (ahl) that they use them as a quorum-sensing signal molecule. pantoea ananatis is reported as a common colonist of wheat heads at ripening and causes center rot of onion. in this study, we demonstrated that p. ananatis sk-1 produced two ahls, n-hexanoyl-l-homoserine lactone (c6-hsl) and n-(3-oxohexanoyl)-l-homoserine lactone (3-oxo-c6-hsl). we cloned the ahl-synthase gene (eani) and ahl-recept ... | 2007 | 17827290 |
| recurrent burkholderia infection in patients with chronic granulomatous disease: 11-year experience at a large referral center. | the epidemiology of burkholderia infection in persons with chronic granulomatous disease is poorly understood. we used species-specific polymerase chain reaction-based assays and genotyping analyses to identify 32 strains representing 9 burkholderia species among 50 isolates recovered from 18 patients with chronic granulomatous disease. we found that recurrent pulmonary infection with distinct burkholderia strains is common in chronic granulomatous disease. | 2009 | 19400745 |
| sepsis by chromobacterium violaceum: first case report from colombia. | chromobacterium violaceum is found in tropical and subtropical regions; it is the only chromobacterium species pathogenic for humans. due to its rare presentation, physicians often ignore the importance of this pathogen. we report a fulminant fatal case of bacteremia in a 38-year-old colombian man. the clinical manifestations were fever, thoracic pain, respiratory failure and death. his condition, from the beginning of clinical diagnosis, went into continuous deterioration, till his death, withi ... | 2007 | 17874003 |
| a probable aculeacin a acylase from the ralstonia solanacearum gmi1000 is n-acyl-homoserine lactone acylase with quorum-quenching activity. | the infection and virulence functions of diverse plant and animal pathogens that possess quorum sensing systems are regulated by n-acylhomoserine lactones (ahls) acting as signal molecules. ahl-acylase is a quorum quenching enzyme and degrades ahls by removing the fatty acid side chain from the homoserine lactone ring of ahls. this blocks ahl accumulation and pathogenic phenotypes in quorum sensing bacteria. | 2009 | 19426552 |
| n-(3-hydroxyhexanoyl)-l-homoserine lactone is the biologically relevant quormone that regulates the phz operon of pseudomonas chlororaphis strain 30-84. | phenazine production by pseudomonas fluorescens 2-79 and p. chlororaphis isolates 30-84 and pcl1391 is regulated by quorum sensing through the activator phzr and acyl-homoserine lactones (acyl-hsls) synthesized by phzi. phzi from p. fluorescens 2-79 produces five acyl-hsls that include four 3-hydroxy species. of these, n-(3-hydroxyhexanoyl)-hsl is the biologically relevant ligand for phzr. the quorum-sensing systems of p. chlororaphis strains 30-84 and pcl1391 have been reported to produce and r ... | 2007 | 17921283 |
| structural basis for the erythro-stereospecificity of the l-arginine oxygenase vioc in viomycin biosynthesis. | the nonheme iron oxygenase vioc from streptomyces vinaceus catalyzes fe(ii)-dependent and alpha-ketoglutarate-dependent cbeta-hydroxylation of l-arginine during the biosynthesis of the tuberactinomycin antibiotic viomycin. crystal structures of vioc were determined in complexes with the cofactor fe(ii), the substrate l-arginine, the product (2s,3s)-hydroxyarginine and the coproduct succinate at 1.1-1.3 a resolution. the overall structure reveals a beta-helix core fold with two additional helical ... | 2009 | 19490124 |
| the long-chain fatty acid sensor, psra, modulates the expression of rpos and the type iii secretion exsceba operon in pseudomonas aeruginosa. | the pseudomonas aeruginosa psra autorepressor has dual roles as a repressor of the fadba5beta-oxidation operon and an activator of the stationary-phase sigma factor rpos and exsceba operon of the type iii secretion system (ttss). previously, we demonstrated that the repression of the fadba5 operon by psra is relieved by long-chain fatty acids (lcfas). however, the signal affecting the activation of rpos and exsc via psra is unknown. in this study, microarray and gene fusion data suggested that l ... | 2009 | 19508282 |
| a novel two-component system bqss-bqsr modulates quorum sensing-dependent biofilm decay in pseudomonas aeruginosa. | pseudomonas aeruginosa can grow either as planktonic- or biofilm-form in response to environmental changes. recent studies show that switching from biofilm to planktonic lifestyle requires rhamnolipids. here we report the identification of a novel twocomponent system bqss-bqsr that regulates biofilm decay in p. aeruginosa. bqss is a multidomain sensor kinase and bqsr is an ompr-like response regulator. deletion of either bqss or bqsr in p. aeruginosa mpao1 resulted in a significant increase in b ... | 2008 | 19513205 |
| successful treatment of chromobacterium violaceum sepsis in south africa. | chromobacterium violaceum sepsis is extremely rare and usually fatal. a very few cases of c. violaceum infection have been reported from africa, but never from south africa. as far as could be ascertained, this infection has never been reported in a patient with leukaemia. we describe what we believe to be the first such case of c. violaceum sepsis, in a 16-year-old female patient with acute biphenotypic leukaemia, which developed during the neutropenic phase after intensive chemotherapy. the in ... | 2008 | 18809561 |
| homologs of the small rna sgrs are broadly distributed in enteric bacteria but have diverged in size and sequence. | sugar phosphate stress in escherichia coli is sensed and managed by the transcriptional regulator sgrr and the small rna (srna) sgrs. sgrs is a dual function rna that performs base pairing-dependent regulation of mrna targets and encodes a small protein, sgrt. homologs of sgrr were analyzed for gene synteny and inter-homolog identity to identify those that are likely to be functionally analogous. these 22 sgrr homologs were used to manually locate adjacent srnas functionally analogous to sgrs. s ... | 2009 | 19531735 |
| non mycobacterial virulence genes in the genome of the emerging pathogen mycobacterium abscessus. | mycobacterium abscessus is an emerging rapidly growing mycobacterium (rgm) causing a pseudotuberculous lung disease to which patients with cystic fibrosis (cf) are particularly susceptible. we report here its complete genome sequence. the genome of m. abscessus (cip 104536t) consists of a 5,067,172-bp circular chromosome including 4920 predicted coding sequences (cds), an 81-kb full-length prophage and 5 is elements, and a 23-kb mercury resistance plasmid almost identical to pmm23 from mycobacte ... | 2009 | 19543527 |
| an fad-dependent pyridine nucleotide-disulfide oxidoreductase is involved in disulfide bond formation in fk228 anticancer depsipeptide. | disulfide bonds are rare in bacterial natural products, and the mechanism of disulfide bond formation in those products is unknown. here we characterize a gene and its product critical for a disulfide bond formation in fk228 anticancer depsipeptide in chromobacterium violaceum. deletion of deph drastically reduced fk228 production, whereas complementation of the deph-deletion mutant with a copy of deph on a medium copy-number plasmid not only fully restored the fk228 production but also signific ... | 2009 | 19549597 |
| synthesis, nematicidal and antimicrobial properties of bis-[4-methoxy-3-[3-(4-fluorophenyl)-6-(4-methylphenyl)-2(aryl)-tetrahydro-2h-pyrazolo[3,4-d]thiazol-5-yl]phenyl]methanes. | a new series of bis-[4-methoxy-3-[3-(4-fluorophenyl)-6-(4-methylphenyl)-2-(aryl)-3,3a,5,6-tetrahydro-2h-pyrazolo[3,4-d][1,3]thiazol-5-yl]phenyl]methanes 6a-r was synthesized by the reaction of arylidine derivative of methylene-bis-thiazolidinones 5a-c with aryl/alkyl hydrazines. chemical structures of all the new compounds were established by ir, (1)h-nmr, (13)c-nmr, ms and elemental data. the compounds 6a-r were evaluated for their nematicidal activity against ditylenchus myceliophagus and caen ... | 2009 | 19571412 |
| blocking of pseudomonas aeruginosa and ralstonia solanacearum lectins by plant and microbial branched polysaccharides used as food additives. | pseudomonas aeruginosa antibiotic resistance prompted the search for glycodecoys that would block its lectin-dependent adhesion to human cells. we have used the lectins of this pathogen, pa-il (galactophilic leca) and pa-iil (fucophilic lecb), and two additional pathogenic bacterial lectins, cv-iil (fucophilic, of chromobacterium violaceum) and rs-iil (mannophilic, of ralstonia solanacearum), for assaying the pathogenic lectin-blocking abilities of some plant and microbial polysaccharidic food a ... | 2009 | 19572540 |
| immunomodulatory, analgesic and antipyretic effects of violacein isolated from chromobacterium violaceum. | violacein was isolated from chromobacterium violaceum, a soil gram negative bacterium collected from the forest water body soil sample of kolli hills; tamil nadu, india. in the present study the immunomodulatory, analgesic and antipyretic activities of violacein were investigated in wistar rats and mice. analgesic effect was evaluated by acetic acid- induced writhing, formalin induced paw licking and hotplate tests. immunomodulatory effect was investigated by using ovalbumin- induced active paw ... | 2010 | 19576742 |
| chromobacterium piscinae sp. nov. and chromobacterium pseudoviolaceum sp. nov., from environmental samples. | two strains (lmg 3947 and lmg 3953) of motile, gram-negative, violet-pigmented bacteria, respectively isolated in 1972 and before 1953 from environmental samples and previously assigned to chromobacterium violaceum, were studied again in detail for their taxonomic position. 16s rrna gene sequence analysis showed that both strains clustered together with the type strain of chromobacterium violaceum (99.8 % sequence similarity for strain lmg 3953(t) and 98.9 % sequence similarity for lmg 3947(t)). ... | 2009 | 19622653 |
| kinetic isotope effects on aromatic and benzylic hydroxylation by chromobacterium violaceum phenylalanine hydroxylase as probes of chemical mechanism and reactivity. | phenylalanine hydroxylase from chromobacterium violaceum (cvpheh) is a non-heme iron monooxygenase that catalyzes the hydroxylation of phenylalanine to tyrosine. in this study, we used deuterium kinetic isotope effects to probe the chemical mechanisms of aromatic and benzylic hydroxylation to compare the reactivities of bacterial and eukaryotic aromatic amino acid hydroxylases. the (d) k cat value for the reaction of cvpheh with [(2)h 5]phenylalanine is 1.2 with 6-methyltetrahydropterin and 1.4 ... | 2008 | 18817418 |
| fatal chromobacterium violaceum septicaemia in northern laos, a modified oxidase test and post-mortem forensic family g6pd analysis. | chromobacterium violaceum is a gram negative facultative anaerobic bacillus, found in soil and stagnant water, that usually has a violet pigmented appearance on agar culture. it is rarely described as a human pathogen, mostly from tropical and subtropical areas. | 2009 | 19640274 |
| pseudogulbenkiania subflava gen. nov., sp. nov., isolated from a cold spring. | a yellow-coloured bacterial strain, designated bp-5(t), was isolated from a water sample of a cold spring located in the hsinchu area of northern taiwan. cells of the strain were gram-negative, non-spore-forming rods with a polar flagellum. the isolate was able to grow at 15-42 degrees c, 0-1 % nacl and ph 6-8. the predominant fatty acids were summed feature 3 (c(16 : 1)omega7c and/or iso-c(15 : 0) 2-oh), c(16 : 0) and c(18 : 1)omega7c. the major respiratory quinone was ubiquinone 8. the dna g+c ... | 2008 | 18842860 |
| metabolic analysis of the soil microbe dechloromonas aromatica str. rcb: indications of a surprisingly complex life-style and cryptic anaerobic pathways for aromatic degradation. | initial interest in dechloromonas aromatica strain rcb arose from its ability to anaerobically degrade benzene. it is also able to reduce perchlorate and oxidize chlorobenzoate, toluene, and xylene, creating interest in using this organism for bioremediation. little physiological data has been published for this microbe. it is considered to be a free-living organism. | 2009 | 19650930 |
| enhancement of l-tryptophan 5-hydroxylation activity by structure-based modification of l-phenylalanine 4-hydroxylase from chromobacterium violaceum. | the objective of this study was to enhance l-tryptophan hydroxylation activity of l-phenylalanine 4-hydroxylase. it had been known that l-phenylalanine 4-hydroxylase from chromobacterium violaceum could convert l-tryptophan to 5-hydroxy-l-tryptophan and l-phenylalanine to l-tyrosine; however, the activity for l-tryptophan was extremely low compared to l-phenylalanine activity levels. we used the information on the crystal structures of aromatic amino acid hydroxylases to generate c. violaceuml-p ... | 2009 | 19664549 |
| efflux-mediated drug resistance in bacteria: an update. | drug efflux pumps play a key role in drug resistance and also serve other functions in bacteria. there has been a growing list of multidrug and drug-specific efflux pumps characterized from bacteria of human, animal, plant and environmental origins. these pumps are mostly encoded on the chromosome, although they can also be plasmid-encoded. a previous article in this journal provided a comprehensive review regarding efflux-mediated drug resistance in bacteria. in the past 5 years, significant pr ... | 2009 | 19678712 |
| tocopherol, carotene, phenolic contents and antibacterial properties of rose essential oil, hydrosol and absolute. | the antioxidant and antibacterial activities, and total phenolic contents of rosa damascena mill. flower extracts (absolute, essential oil and hydrosol) were investigated. the chemical compositions of these extracts were analysed by gc-ms. phenylethyl alcohol (78.38%) was found to be the main constituent of rose absolute, while citrenellol and geraniol were the major compounds (>55%) of rose essential oil and hydrosol. tocopherol and carotene levels were determined by high performance liquid chr ... | 2009 | 19688375 |
| anti-diarrhoeal and ulcer-protective effects of violacein isolated from chromobacterium violaceum in wistar rats. | violacein was isolated from chromobacterium violaceum, a soil gram-negative bacterium collected from the forest water body soil sample from kolli hills of tamil nadu, india. in the present study the anti-diarrhoeal and ulcer-protective properties of violacein were investigated in wistar rats using castor oil, magnesium sulphate and ethanol. the intestinal transit in rats was significantly (p < 0.001) reduced and gastric emptying was delayed; 40 mg/kg of violacein elicited a greater anti-motility ... | 2009 | 19709325 |
| quorum sensing inhibition activity of garlic extract and p-coumaric acid. | the goal of this work was to investigate the influence of dmso, garlic extract and p-coumaric acid on bacterial quorum sensing (qs). | 2009 | 19709367 |
| single-residue changes in the c-terminal disulfide-bonded loop of the pseudomonas aeruginosa type iv pilin influence pilus assembly and twitching motility. | pila, the major pilin subunit of pseudomonas aeruginosa type iv pili (t4p), is a principal structural component. pila has a conserved c-terminal disulfide-bonded loop (dsl) that has been implicated as the pilus adhesinotope. structural studies have suggested that dsl is involved in intersubunit interactions within the pilus fiber. pila mutants with single-residue substitutions, insertions, or deletions in the dsl were tested for pilin stability, pilus assembly, and t4p function. mutation of eith ... | 2009 | 19717595 |
| ion channels in microbes. | studies of ion channels have for long been dominated by the animalcentric, if not anthropocentric, view of physiology. the structures and activities of ion channels had, however, evolved long before the appearance of complex multicellular organisms on earth. the diversity of ion channels existing in cellular membranes of prokaryotes is a good example. although at first it may appear as a paradox that most of what we know about the structure of eukaryotic ion channels is based on the structure of ... | 2008 | 18923187 |
| protozoan-induced regulation of cyclic lipopeptide biosynthesis is an effective predation defense mechanism for pseudomonas fluorescens. | environmental bacteria are exposed to a myriad of biotic interactions that influence their function and survival. the grazing activity of protozoan predators significantly impacts the dynamics, diversification, and evolution of bacterial communities in soil ecosystems. to evade protozoan predation, bacteria employ various defense strategies. soil-dwelling pseudomonas fluorescens strains ss101 and sbw25 produce the cyclic lipopeptide surfactants (clps) massetolide and viscosin, respectively, in a ... | 2009 | 19717630 |
| chromobacterium violaceum sepsis in an infant. | chromobacterium violaceum is a rare pathogen that can cause potentially fatal infections in humans. till date, 150 cases are reported worldwide including 7 from india. we report a 6 month old infant who presented with high grade fever, respiratory distress and multiple vesicular skin lesions. chromobacterium violaceum was isolated from blood, bone marrow aspirate and from skin lesions. infant responded to treatment with piperacillin and ciprofloxacin, and is doing well on follow up. | 2009 | 19717863 |
| neonatal enteral feeding tubes as loci for colonisation by members of the enterobacteriaceae. | the objective of this study was to determine whether neonatal nasogastric enteral feeding tubes are colonised by the opportunistic pathogen cronobacter spp. (enterobacter sakazakii) and other enterobacteriaceae, and whether their presence was influenced by the feeding regime. | 2009 | 19723318 |
| color me bad: microbial pigments as virulence factors. | a hallmark feature of several pathogenic microbes is the distinctive color of their colonies when propagated in the clinical laboratory. such pigmentation comes in a variety of hues, and has often proven useful in presumptive clinical diagnosis. recent advances in microbial pigment biochemistry and the genetic basis of pigment production have sometimes revealed a more sinister aspect to these curious materials that change the color of reflected light by selective light absorbance. in many cases, ... | 2009 | 19726196 |
| the pmra/pmrb two-component system of legionella pneumophila is a global regulator required for intracellular replication within macrophages and protozoa. | to examine the role of the pmra/pmrb two-component system (tcs) of legionella pneumophila in global gene regulation and in intracellular infection, we constructed pmra and pmrb isogenic mutants by allelic exchange. genome-wide microarray gene expression analyses of the pmra and pmrb mutants at both the exponential and the postexponential phases have shown that the pmra/pmrb tcs has a global effect on the expression of 279 genes classified into nine groups of genes encoding eukaryotic-like protei ... | 2009 | 18936184 |
| efficient synthesis and evaluation of quorum-sensing modulators using small molecule macroarrays. | a method for the synthesis of small molecule macroarrays of n-acylated l-homoserine lactones (ahls) is reported. a focused library of ahls was constructed, and the macroarray platform was found to be compatible with both solution and agar-overlay assays using quorum-sensing (qs) reporter strains. several qs antagonists were discovered and serve to showcase the macroarray as a straightforward technique for qs research. | 2009 | 19743816 |
| rapid hydrolysis of quorum-sensing molecules in the gut of lepidopteran larvae. | microorganisms compete for nutrients and living space in the gut of plant-feeding insect larvae, such as spodoptera spp. their physiological activities and their organization are generally controlled or synchronised by "autoinducers", such as n-acylhomoserinelactones (ahls). due to the strongly alkaline milieu in the insect gut, the lactone ring of ahls is rapidly and spontaneously opened. further degradation to the inactive components homoserine and the acyl moiety is then achieved by a microbi ... | 2008 | 18642255 |
| quorum-sensing signals in the microbial community of the cabbage white butterfly larval midgut. | the overall goal of this study was to examine the role of quorum-sensing (qs) signals in a multispecies microbial community. toward this aim, we studied qs signals produced by an indigenous member and an invading pathogen of the microbial community of the cabbage white butterfly (cwb) larval midgut (pieris rapae). as an initial step, we characterized the qs system in pantoea cwb304, which was isolated from the larval midgut. a luxi homolog, designated pani, is necessary for the production of n-a ... | 2008 | 18650927 |
| inhibition of bacterial quorum sensing-regulated behaviors by tremella fuciformis extract. | quorum sensing (qs), or the control of gene expression in response to cell density, is used by both gram-negative and gram-positive bacteria to regulate a variety of physiological functions. increasing evidence implies that certain eukaryotes produce qs-inhibitory compounds. in this work, we tested tremella fuciformis for their ability to inhibit qs-regulated behaviors. t. fuciformis fruiting bodies were dried and extracted using 75% (v/v) aqueous methanol. the crude extract was redissolved in a ... | 2008 | 18661179 |
| polyhydroxyalkanoate (pha) production using waste vegetable oil by pseudomonas sp. strain dr2. | to produce polyhydroxyalkanoate (pha) from inexpensive substrates by bacteria, vegetable-oil-degrading bacteria were isolated from a rice field using enrichment cultivation. the isolated pseudomonas sp. strain dr2 showed clear orange or red spots of accumulated pha granules when grown on phosphate and nitrogen limited medium containing vegetable oil as the sole carbon source and stained with nile blue a. up to 37.34% (w/w) of intracellular pha was produced from corn oil, which consisted of three ... | 2008 | 18756101 |
| the pmra/pmrb two-component system of legionella pneumophila is a global regulator required for intracellular replication within macrophages and protozoa. | to examine the role of the pmra/pmrb two-component system (tcs) of legionella pneumophila in global gene regulation and in intracellular infection, we constructed pmra and pmrb isogenic mutants by allelic exchange. genome-wide microarray gene expression analyses of the pmra and pmrb mutants at both the exponential and the postexponential phases have shown that the pmra/pmrb tcs has a global effect on the expression of 279 genes classified into nine groups of genes encoding eukaryotic-like protei ... | 2009 | 18936184 |
| phase ii trial of romidepsin (nsc-630176) in previously treated colorectal cancer patients with advanced disease: a southwest oncology group study (s0336). | patients with metastatic colorectal cancer who progress on standard chemotherapy have limited treatment options. new and effective drugs are needed for these patients. romidepsin is a histone deacetylase inhibitor that can alter chromatin structure and gene transcription leading to multiple changes in cellular protein production. this may result in cell cycle arrest and tumor growth inhibition. romidepsin has shown anti-proliferative activity in vitro against multiple mouse and human tumor cell ... | 2009 | 18941712 |
| phase ii trial of romidepsin (nsc-630176) in previously treated colorectal cancer patients with advanced disease: a southwest oncology group study (s0336). | patients with metastatic colorectal cancer who progress on standard chemotherapy have limited treatment options. new and effective drugs are needed for these patients. romidepsin is a histone deacetylase inhibitor that can alter chromatin structure and gene transcription leading to multiple changes in cellular protein production. this may result in cell cycle arrest and tumor growth inhibition. romidepsin has shown anti-proliferative activity in vitro against multiple mouse and human tumor cell ... | 2009 | 18941712 |
| the role of histone deacetylases in prostate cancer. | epigenetic modifications play a key role in the patho-physiology of prostate cancer. histone deacetylases (hdacs) play major roles in prostate cancer progression. hdacs are part of a transcriptional co-repressor complex that influences various tumor suppressor genes. because of the significant roles played by hdacs in various human cancers, hdac inhibitors are emerging as a new class of chemotherapeutic agents. hdac inhibitors have been shown to induce cell growth arrest, differentiation and/or ... | 2008 | 19029799 |
| multiple roles of pseudomonas aeruginosa tbcf10839 pily1 in motility, transport and infection. | polymorphonuclear neutrophils are the most important mammalian host defence cells against infections with pseudomonas aeruginosa. screening of a signature tagged mutagenesis library of the non-piliated p. aeruginosa strain tbcf10839 uncovered that transposon inactivation of its pily1 gene rendered the bacterium more resistant against killing by neutrophils than the wild type and any other of the more than 3000 tested mutants. inactivation of pily1 led to the loss of twitching motility in twitchi ... | 2009 | 19054330 |
| secondary metabolites produced by the marine bacterium halobacillus salinus that inhibit quorum sensing-controlled phenotypes in gram-negative bacteria. | certain bacteria use cell-to-cell chemical communication to coordinate community-wide phenotypic expression, including swarming motility, antibiotic biosynthesis, and biofilm production. here we present a marine gram-positive bacterium that secretes secondary metabolites capable of quenching quorum sensing-controlled behaviors in several gram-negative reporter strains. isolate c42, a halobacillus salinus strain obtained from a sea grass sample, inhibits bioluminescence production by vibrio harve ... | 2009 | 19060172 |
| synchronous gene expression of the yersinia enterocolitica ysa type iii secretion system and its effectors. | type iii secretion systems (t3sss) are complex units that consist of many proteins. often the proteins are encoded as a cohesive unit on virulence plasmids, but several systems have their various components dispersed around the chromosome. the yersinia enterocolitica ysa t3ss is such a system, where the apparatus genes, some regulatory genes, and four genes encoding secreted proteins (ysp genes) are contained in a single locus. the remaining ysp genes and at least one additional regulator are fo ... | 2009 | 19124573 |
| histone deacetylase inhibitor romidepsin enhances anti-tumor effect of erlotinib in non-small cell lung cancer (nsclc) cell lines. | most epidermal growth factor receptor (egfr) mutant non-small cell lung cancers (nsclcs) are sensitive to egfr tyrosine kinase inhibitors (tkis) such as erlotinib or gefitinib, but many egfr wild type nsclcs are resistant to tkis. in this study, we examined the effects of the histone deacetylase inhibitor, romidepsin, in combination with erlotinib, in nsclc cell lines and xenografts. | 2009 | 19179890 |
| chromobacterium violaceum infection in a provincial hospital in sri lanka. | | 2008 | 19189802 |
| population pharmacokinetics of romidepsin in patients with cutaneous t-cell lymphoma and relapsed peripheral t-cell lymphoma. | romidepsin is a potent histone deacetylase inhibitor under clinical development. the objective of this study was to evaluate the effect of demographic, clinical, and pharmacogenetic covariates on the pharmacokinetics of romidepsin in patients with t-cell lymphoma. | 2009 | 19228751 |
| is gas-discharge plasma a new solution to the old problem of biofilm inactivation? | conventional disinfection and sterilization methods are often ineffective with biofilms, which are ubiquitous, hard-to-destroy microbial communities embedded in a matrix mostly composed of exopolysaccharides. the use of gas-discharge plasmas represents an alternative method, since plasmas contain a mixture of charged particles, chemically reactive species and uv radiation, whose decontamination potential for free-living, planktonic micro-organisms is well established. in this study, biofilms wer ... | 2009 | 19246743 |
| chromobacterium violaceum endocarditis and hepatic abscesses treated successfully with meropenem and ciprofloxacin. | chromobacterium violaceum infection is uncommon but potentially fatal, with a clinical picture similar to melioidosis but with different antibiotic sensitivities and treatment. this infection can involve any organ, but we believe this is the first reported case of c. violaceum endocarditis. | 2009 | 19351314 |
| recurrent chromobacterium violaceum infection in a patient with chronic granulomatous disease. | we report a rare case of recurrent infection of chromobacterium violaceum in an immunocompromised patient. despite the high mortality rate associated with this infection as reported in the literature, this patient survived three episodes of recurrent infection. we believe that with high clinical suspicion, prompt treatment and appropriate antimicrobial agents, it is possible for clinicians to treat this infection effectively and reduce the mortality rate. | 2008 | 19385503 |
| oxidative dna damage protective activity, antioxidant and anti-quorum sensing potentials of moringa oleifera. | the aqueous extract of leaf (le), fruit (fe) and seed (se) of moringa oleifera was assessed to examine the ability to inhibit the oxidative dna damage, antioxidant and anti-quorum sensing (qs) potentials. it was found that these extracts could significantly inhibit the oh-dependent damage of puc18 plasmid dna and also inhibit synergistically with trolox, with an activity sequence of le > fe > se. hplc and ms/ms analysis was carried out, which showed the presence of gallic acid, chlorogenic acid, ... | 2009 | 19425184 |
| a rationally designed histone deacetylase inhibitor with distinct antitumor activity against ovarian cancer. | histone deacetylase inhibitors (hdacis) are a class of antineoplastic agents previously demonstrating preclinical chemosensitizing activity against drug-resistant cancer cells and mouse xenografts. however, whereas clinical studies have shown efficacy against human hematologic malignancies, solid tumor trials have proved disappointing. we previously developed a novel hdaci, "osu-hdac42," and herein examine its activity against ovarian cancer cell lines and xenografts. osu-hdac42, (i) unlike most ... | 2009 | 19484144 |
| lasi/r and rhli/r quorum sensing in a strain of pseudomonas aeruginosa beneficial to plants. | pseudomonas aeruginosa possesses three quorum-sensing (qs) systems which are key in the expression of a large number of genes, including many virulence factors. most studies of qs in p. aeruginosa have been performed in clinical isolates and have therefore focused on its role in pathogenicity. p. aeruginosa, however, is regarded as a ubiquitous organism capable of colonizing many different environments and also of establishing beneficial associations with plants. in this study we examined the ro ... | 2009 | 19525275 |
| inhibition of quorum sensing regulated bacterial functions by plant essential oils with special reference to clove oil. | to evaluate quorum sensing (qs) inhibitory activity of plant essential oils using strains of chromobacterium violaceum (cv12472 and cvo26) and pseudomonas aeruginosa (pao1). | 2009 | 19627477 |
| a quorum-sensing antagonist targets both membrane-bound and cytoplasmic receptors and controls bacterial pathogenicity. | quorum sensing is a process of bacterial communication involving production and detection of secreted molecules called autoinducers. gram-negative bacteria use acyl-homoserine lactone (ahl) autoinducers, which are detected by one of two receptor types. first, cytoplasmic luxr-type receptors bind accumulated intracellular ahls. ahl-luxr complexes bind dna and alter gene expression. second, membrane-bound luxn-type receptors bind accumulated extracellular ahls. ahl-luxn complexes relay information ... | 2009 | 19647512 |
| the bacterially produced metabolite violacein is associated with survival of amphibians infected with a lethal fungus. | the disease chytridiomycosis, which is caused by the chytrid fungus batrachochytrium dendrobatidis, is associated with recent declines in amphibian populations. susceptibility to this disease varies among amphibian populations and species, and resistance appears to be attributable in part to the presence of antifungal microbial species associated with the skin of amphibians. the betaproteobacterium janthinobacterium lividum has been isolated from the skins of several amphibian species and produc ... | 2009 | 19717627 |
| n-acylhomoserine lactones involved in quorum sensing control the type vi secretion system, biofilm formation, protease production, and in vivo virulence in a clinical isolate of aeromonas hydrophila. | in this study, we delineated the role of n-acylhomoserine lactone(s) (ahls)-mediated quorum sensing (qs) in the virulence of diarrhoeal isolate ssu of aeromonas hydrophila by generating a double knockout delta ahyri mutant. protease production was substantially reduced in the delta ahyri mutant when compared with that in the wild-type (wt) strain. importantly, based on western blot analysis, the delta ahyri mutant was unable to secrete type vi secretion system (t6ss)-associated effectors, namely ... | 2009 | 19729404 |
| zinc-independent folate biosynthesis: genetic, biochemical, and structural investigations reveal new metal dependence for gtp cyclohydrolase ib. | gtp cyclohydrolase i (gcyh-i) is an essential zn(2+)-dependent enzyme that catalyzes the first step of the de novo folate biosynthetic pathway in bacteria and plants, the 7-deazapurine biosynthetic pathway in bacteria and archaea, and the biopterin pathway in mammals. we recently reported the discovery of a new prokaryotic-specific gcyh-i (gcyh-ib) that displays no sequence identity to the canonical enzyme and is present in approximately 25% of bacteria, the majority of which lack the canonical ... | 2009 | 19767425 |
| mediators of lipid a modification, rna degradation, and central intermediary metabolism facilitate the growth of legionella pneumophila at low temperatures. | legionella pneumophila is an aquatic bacterium that is also the agent of legionnaires' disease pneumonia. since l. pneumophila is transmitted directly from the environment to the lung, it is important to understand how legionellae survive at low temperatures. to identify genes that are needed for l. pneumophila growth at low temperature, we screened a population of mutagenized legionellae for strains that are specifically impaired for growth at 17 degrees c. from the 7,400 mutants tested, 11 dis ... | 2010 | 19768502 |
| mediators of lipid a modification, rna degradation, and central intermediary metabolism facilitate the growth of legionella pneumophila at low temperatures. | legionella pneumophila is an aquatic bacterium that is also the agent of legionnaires' disease pneumonia. since l. pneumophila is transmitted directly from the environment to the lung, it is important to understand how legionellae survive at low temperatures. to identify genes that are needed for l. pneumophila growth at low temperature, we screened a population of mutagenized legionellae for strains that are specifically impaired for growth at 17 degrees c. from the 7,400 mutants tested, 11 dis ... | 2010 | 19768502 |
| [cloning of phzir from the endophytic pseudomonas sp. g5 and its expression in escherichia coli]. | we isolated a new strain of endophytic pseudomonas g5 from the stems of chinese parsley (coriandrum sativum l.), and it is tentatively identified as pseudomonas aurantiaca according to analysis of the entire substrate utilization profiles using biolog microstation system (biolog, inc, hayward ca). an array of evidence established that many gram-negative bacteria employ quorum sensing (qs) system to regulate gene expression in response to cell density using small diffusible signal molecules, n-ac ... | 2009 | 19777809 |
| microbial growth and quorum sensing antagonist activities of herbal plants extracts. | antimicrobial and antiquorum sensing (aqs) activities of fourteen ethanolic extracts of different parts of eight plants were screened against four gram-positive, five gram-negative bacteria and four fungi. depending on the plant part extract used and the test microorganism, variable activities were recorded at 3 mg per disc. among the grampositive bacteria tested, for example, activities of laurus nobilis bark extract ranged between a 9.5 mm inhibition zone against bacillus subtilis up to a 25 m ... | 2009 | 19783935 |
| expression of phosphofructokinase in neisseria meningitidis. | neisseria meningitidis serogroup b is a pathogen that can infect diverse sites within the human host. according to the n. meningitidis genomic information and experimental observations, glucose can be completely catabolized through the entner-doudoroff pathway and the pentose phosphate pathway. the embden-meyerhof-parnas pathway is not functional, because the gene for phosphofructokinase (pfk) is not present. the phylogenetic distribution of pfk indicates that in most obligate aerobic organisms, ... | 2010 | 19797358 |
| chromobacterium violaceum endocarditis and hepatic abscesses treated successfully with meropenem and ciprofloxacin. | | 2009 | 19807647 |
| legionella pneumophila secretes an endoglucanase that belongs to the family-5 of glycosyl hydrolases and is dependent upon type ii secretion. | examination of cell-free culture supernatants revealed that legionella pneumophila strains secrete an endoglucanase activity. legionella pneumophila lspf mutants were deficient for this activity, indicating that the endoglucanase is secreted by the bacterium's type ii protein secretion (t2s) system. inactivation of cela, encoding a member of the family-5 of glycosyl hydrolases, abolished the endoglucanase activity in l. pneumophila culture supernatants. the cloned cela gene conferred activity up ... | 2009 | 19817866 |
| 2-amino-3-(oxirane-2,3-dicarboxamido)-propanoyl-valine, an effective peptide antibiotic from the epiphyte pantoea agglomerans 48b/90. | the epiphyte pantoea agglomerans 48b/90, which has been isolated from soybean leaves, belongs to the enterobacteriaceae, as does the plant pathogen erwinia amylovora, which causes fire blight on rosaceous plants such as apples and leads to severe economic losses. since p. agglomerans efficiently antagonizes phytopathogenic bacteria, the p. agglomerans strain c9-1 is used as a biocontrol agent (blightban c9-1). here we describe the bioassay-guided isolation of a peptide antibiotic that is highly ... | 2009 | 19820144 |
| inhibition of quorum-sensing signals by essential oils. | the role of quorum sensing (qs) is well known in microbial pathogenicity and antibiotic resistance. qs is responsible for motility, swarming, and biofilm production based on the signal molecules, e.g., acylated homoserine lactones (ahls) produced by micro-organisms above certain population density. the inhibition of qs may reduce pathogenicity, antibiotic resistance and biofilm formation in systemic and local infections. the homoserine lactones and other transmitters contribute to antibiotic res ... | 2010 | 19827025 |