| comparative transcriptomic analysis of the burkholderia cepacia tyrosine kinase bcef mutant reveals a role in tolerance to stress, biofilm formation, and virulence. | the bacterial tyrosine-kinase (by-kinase) family comprises the major group of bacterial enzymes endowed with tyrosine kinase activity. we previously showed that the bcef protein from burkholderia cepacia ist408 belongs to this by-kinase family and is involved in the biosynthesis of the exopolysaccharide cepacian. however, little is known about the extent of regulation of this protein kinase activity. in order to examine this regulation, we performed a comparative transcriptome profile between th ... | 2013 | 23435894 |
| reducing virulence of the human pathogen burkholderia by altering the substrate specificity of the quorum-quenching acylase pvdq. | the use of enzymes to interfere with quorum sensing represents an attractive strategy to fight bacterial infections. we used pvdq, an effective quorum-quenching enzyme from pseudomonas aeruginosa, as a template to generate an acylase able to effectively hydrolyze c8-hsl, the major communication molecule produced by the burkholderia species. we discovered that the combination of two single mutations leading to variant pvdq(lα146w,fβ24y) conferred high activity toward c8-hsl. exogenous addition of ... | 2014 | 24474783 |
| iron is a signal for stenotrophomonas maltophilia biofilm formation, oxidative stress response, omps expression, and virulence. | stenotrophomonas maltophilia is an emerging nosocomial pathogen. in many bacteria iron availability regulates, through the fur system, not only iron homeostasis but also virulence. the aim of this work was to assess the role of iron on s. maltophilia biofilm formation, eps production, oxidative stress response, omps regulation, quorum sensing (qs), and virulence. studies were done on k279a and its isogenic fur mutant f60 cultured in the presence or absence of dipyridyl. this is the first report ... | 2015 | 26388863 |
| inhibition of aac(6')-ib-mediated resistance to amikacin in acinetobacter baumannii by an antisense peptide-conjugated 2',4'-bridged nucleic acid-nc-dna hybrid oligomer. | multiresistant acinetobacter baumannii, a common etiologic agent of severe nosocomial infections in compromised hosts, usually harbors aac(6')-ib. this gene specifies resistance to amikacin and other aminoglycosides, seriously limiting the effectiveness of these antibiotics. an antisense oligodeoxynucleotide (odn4) that binds to a duplicated sequence on the aac(6')-ib mrna, one of the copies overlapping the initiation codon, efficiently inhibited translation in vitro. an isosequential nuclease-r ... | 2015 | 26169414 |
| burkholderia cenocepacia lipopolysaccharide modification and flagellin glycosylation affect virulence but not innate immune recognition in plants. | burkholderia cenocepacia causes opportunistic infections in plants, insects, animals, and humans, suggesting that "virulence" depends on the host and its innate susceptibility to infection. we hypothesized that modifications in key bacterial molecules recognized by the innate immune system modulate host responses to b. cenocepacia. indeed, modification of lipopolysaccharide (lps) with 4-amino-4-deoxy-l-arabinose and flagellin glycosylation attenuates b. cenocepacia infection in arabidopsis thali ... | 2015 | 26045541 |
| tyrosine phosphorylation and dephosphorylation in burkholderia cenocepacia affect biofilm formation, growth under nutritional deprivation, and pathogenicity. | burkholderia cenocepacia, a member of the b. cepacia complex (bcc), is an opportunistic pathogen causing serious chronic infections in patients with cystic fibrosis. tyrosine phosphorylation has emerged as an important posttranslational modification modulating the physiology and pathogenicity of bcc bacteria. here, we investigated the predicted bacterial tyrosine kinases bcam1331 and bcef and the low-molecular-weight protein tyrosine phosphatases bcam0208, bced, and bcal2200 of b. cenocepacia k5 ... | 2016 | 26590274 |
| a multi-host approach for the systematic analysis of virulence factors in cryptococcus neoformans. | a multi-host approach was followed to screen a library of 1201 signature-tagged deletion strains of cryptococcus neoformans mutants to identify previously unknown virulence factors. the primary screen was performed using a caenorhabditis elegans-c. neoformans infection assay. the hits among these strains were reconfirmed as less virulent than the wild type in the insect galleria mellonella-c. neoformans infection assay. after this 2-stage screen, and to prioritize hits, we performed serial evalu ... | 2014 | 25114160 |
| acinetobacter baumannii virulence is mediated by the concerted action of three phospholipases d. | acinetobacter baumannii causes a broad range of opportunistic infections in humans. its success as an emerging pathogen is due to a combination of increasing antibiotic resistance, environmental persistence and adaptation to the human host. to date very little is known about the molecular basis of the latter. here we demonstrate that a. baumannii can use phosphatidylcholine, an integral part of human cell membranes, as sole carbon and energy source. we report on the identification of three phosp ... | 2015 | 26379240 |
| flhf is required for swarming motility and full pathogenicity of bacillus cereus. | besides sporulation, bacillus cereus can undergo a differentiation process in which short swimmer cells become elongated and hyperflagellated swarmer cells that favor migration of the bacterial community on a surface. the functionally enigmatic flagellar protein flhf, which is the third paralog of the signal recognition particle (srp) gtpases ffh and ftsy, is required for swarming in many bacteria. previous data showed that flhf is involved in the control of the number and positioning of flagell ... | 2016 | 27807433 |
| genetic and proteomic characterization of rpob mutations and their effect on nematicidal activity in photorhabdus luminescens ln2. | rifampin resistant (rif(r)) mutants of the insect pathogenic bacterium photorhabdus luminescens ln2 from entomopathogenic nematode heterorhabditis indica ln2 were genetically and proteomically characterized. the rif(r) mutants showed typical phase one characters of photorhabdus bacteria, and insecticidal activity against galleria mellonella larvae, but surprisingly influenced their nematicidal activity against axenic infective juveniles (ijs) of h. bacteriophora h06, an incompatible nematode hos ... | 2012 | 22912803 |
| functional features of tonb energy transduction systems of acinetobacter baumannii. | acinetobacter baumannii is an opportunistic pathogen that causes severe nosocomial infections. strain atcc 19606(t) utilizes the siderophore acinetobactin to acquire iron under iron-limiting conditions encountered in the host. accordingly, the genome of this strain has three tonb genes encoding proteins for energy transduction functions needed for the active transport of nutrients, including iron, through the outer membrane. phylogenetic analysis indicates that these tonb genes, which are presen ... | 2013 | 23817614 |
| medically relevant acinetobacter species require a type ii secretion system and specific membrane-associated chaperones for the export of multiple substrates and full virulence. | acinetobacter baumannii, a. nosocomialis, and a. pittii have recently emerged as opportunistic human pathogens capable of causing severe human disease; however, the molecular mechanisms employed by acinetobacter to cause disease remain poorly understood. many pathogenic members of the genus acinetobacter contain genes predicted to encode proteins required for the biogenesis of a type ii secretion system (t2ss), which have been shown to mediate virulence in many gram-negative organisms. here we d ... | 2016 | 26764912 |
| heterologous expression of bartonella adhesin a in escherichia coli by exchange of trimeric autotransporter adhesin domains results in enhanced adhesion properties and a pathogenic phenotype. | human-pathogenic bartonella henselae causes cat scratch disease and vasculoproliferative disorders. an important pathogenicity factor of b. henselae is the trimeric autotransporter adhesin (taa) bartonella adhesin a (bada), which is modularly constructed, consisting of a head, a long and repetitive neck-stalk module, and a membrane anchor. bada is involved in bacterial autoagglutination, binding to extracellular matrix proteins and host cells, and in proangiogenic reprogramming. the slow growth ... | 2014 | 24682330 |
| stress response and virulence functions of the acinetobacter baumannii nfua fe-s scaffold protein. | to successfully establish an infection, acinetobacter baumannii must overcome the iron starvation and oxidative stress imposed by the human host. although previous studies have shown that atcc 19606(t) cells acquire iron via the acinetobactin-mediated siderophore system, little is known about intracellular iron metabolism and its relation to oxidative stress in this pathogen. screening of an insertion library resulted in the isolation of the atcc 19606(t) derivative 1644, which was unable to gro ... | 2012 | 22467784 |
| anti-legionella dumoffii activity of galleria mellonella defensin and apolipophorin iii. | the gram-negative bacterium legionella dumoffii is, beside legionella pneumophila, an etiological agent of legionnaires' disease, an atypical form of pneumonia. the aim of this study was to determine the antimicrobial activity of galleria mellonella defense polypeptides against l. dumoffii. the extract of immune hemolymph, containing a mixture of defense peptides and proteins, exhibited a dose-dependent bactericidal effect on l. dumoffii. the bacterium appeared sensitive to a main component of t ... | 2012 | 23235329 |
| use of galleria mellonella as a model organism to study legionella pneumophila infection. | legionella pneumophila, the causative agent of a severe pneumonia named legionnaires' disease, is an important human pathogen that infects and replicates within alveolar macrophages. its virulence depends on the dot/icm type iv secretion system (t4ss), which is essential to establish a replication permissive vacuole known as the legionella containing vacuole (lcv). l. pneumophila infection can be modeled in mice however most mouse strains are not permissive, leading to the search for novel infec ... | 2013 | 24299965 |
| ltpd is a novel legionella pneumophila effector that binds phosphatidylinositol 3-phosphate and inositol monophosphatase impa1. | the dot/icm type iv secretion system (t4ss) of legionella pneumophila is crucial for the pathogen to survive in protozoa and cause human disease. although more than 275 effector proteins are delivered into the host cell by the t4ss, the function of the majority is unknown. here we have characterized the dot/icm effector ltpd. during infection, ltpd localized to the cytoplasmic face of the membrane of the legionella-containing vacuole (lcv). in a549 lung epithelial cells, ectopically expressed lt ... | 2013 | 24002062 |
| gene flow in environmental legionella pneumophila leads to genetic and pathogenic heterogeneity within a legionnaires' disease outbreak. | legionnaires' disease is a severe form of pneumonia caused by the environmental bacterium legionella pneumophila. outbreaks commonly affect people with known risk factors, but the genetic and pathogenic complexity of l. pneumophila within an outbreak is not well understood. here, we investigate the etiology of the major legionnaires' disease outbreak that occurred in edinburgh, uk, in 2012, by examining the evolutionary history, genome content, and virulence of l. pneumophila clinical isolates. | 2014 | 25370747 |
| characterization of the fkbp12-encoding genes in aspergillus fumigatus. | invasive aspergillosis, largely caused by aspergillus fumigatus, is responsible for a growing number of deaths among immunosuppressed patients. immunosuppressants such as fk506 (tacrolimus) that target calcineurin have shown promise for antifungal drug development. fk506-binding proteins (fkbps) form a complex with calcineurin in the presence of fk506 (fkbp12-fk506) and inhibit calcineurin activity. research on fkbps in fungi is limited, and none of the fkbps have been previously characterized i ... | 2015 | 26366742 |
| effector protein cig2 decreases host tolerance of infection by directing constitutive fusion of autophagosomes with the coxiella-containing vacuole. | coxiella burnetii replicates in an acidified lysosome-derived vacuole. biogenesis of the coxiella-containing vacuole (ccv) requires bacterial effector proteins delivered into host cells by the dot/icm secretion system. genetic and cell biological analysis revealed that an effector protein called cig2 promotes constitutive fusion of autophagosomes with the ccv to maintain this compartment in an autolysosomal stage of maturation. this distinguishes the ccv from other pathogen-containing vacuoles t ... | 2016 | 27435465 |
| coxiella burnetii effector cvpb modulates phosphoinositide metabolism for optimal vacuole development. | the q fever bacterium coxiella burnetii replicates inside host cells within a large coxiella-containing vacuole (ccv) whose biogenesis relies on the dot/icm-dependent secretion of bacterial effectors. several membrane trafficking pathways contribute membranes, proteins, and lipids for ccv biogenesis. these include the endocytic and autophagy pathways, which are characterized by phosphatidylinositol 3-phosphate [pi(3)p]-positive membranes. here we show that the c. burnetii secreted effector coxie ... | 2016 | 27226300 |
| virulence-related traits of epidemic acinetobacter baumannii strains belonging to the international clonal lineages i-iii and to the emerging genotypes st25 and st78. | acinetobacter baumannii is responsible for large epidemics in hospitals, where it can persist for long time on abiotic surfaces. this study investigated some virulence-related traits of epidemic a. baumannii strains assigned to distinct mlst genotypes, including those corresponding to the international clones i-iii as well as emerging genotypes responsible for recent epidemics. | 2013 | 23786621 |
| developing galleria mellonella as a model host for human pathogens. | | 2013 | 23799664 |
| activities of vancomycin-containing regimens against colistin-resistant acinetobacter baumannii clinical strains. | treatment of infections due to extensively drug-resistant (xdr) acinetobacter baumannii often involves the use of antimicrobial agents in combination. various combinations of agents have been proposed, with colistin serving as the backbone in many of them. recent data suggest that glycopeptides, in particular vancomycin, may have unique activity against laboratory-adapted and clinical strains of a. baumannii, alone and in combination with colistin. the aim of the present study was to test this a ... | 2013 | 23422916 |
| antifungal efficacy during candida krusei infection in non-conventional models correlates with the yeast in vitro susceptibility profile. | the incidence of opportunistic fungal infections has increased in recent decades due to the growing proportion of immunocompromised patients in our society. candida krusei has been described as a causative agent of disseminated fungal infections in susceptible patients. although its prevalence remains low among yeast infections (2-5%), its intrinsic resistance to fluconazole makes this yeast important from epidemiologic aspects. non mammalian organisms are feasible models to study fungal virulen ... | 2013 | 23555877 |
| photodynamic and antibiotic therapy impair the pathogenesis of enterococcus faecium in a whole animal insect model. | enterococcus faecium has emerged as one of the most important pathogens in healthcare-associated infections worldwide due to its intrinsic and acquired resistance to many antibiotics, including vancomycin. antimicrobial photodynamic therapy (apdt) is an alternative therapeutic platform that is currently under investigation for the control and treatment of infections. pdt is based on the use of photoactive dye molecules, widely known as photosensitizer (ps). ps, upon irradiation with visible ligh ... | 2013 | 23457486 |
| adenylate kinase release as a high-throughput-screening-compatible reporter of bacterial lysis for identification of antibacterial agents. | adenylate kinase (ak) is a ubiquitous intracellular enzyme that is released into the extracellular space upon cell lysis. we have shown that ak release serves as a useful reporter of bactericidal agent activity and can be exploited for antimicrobial screening purposes. the ak assay exhibits improved sensitivity over that of growth-based assays and can detect agents that are active against bacteria in clinically relevant growth states that are difficult to screen using conventional approaches, su ... | 2013 | 23027196 |
| an eye to a kill: using predatory bacteria to control gram-negative pathogens associated with ocular infections. | ocular infections are a leading cause of vision loss. it has been previously suggested that predatory prokaryotes might be used as live antibiotics to control infections. in this study, pseudomonas aeruginosa and serratia marcescens ocular isolates were exposed to the predatory bacteria micavibrio aeruginosavorus and bdellovibrio bacteriovorus. all tested s. marcescens isolates were susceptible to predation by b. bacteriovorus strains 109j and hd100. seven of the 10 p. aeruginosa isolates were s ... | 2013 | 23824756 |
| animals devoid of pulmonary system as infection models in the study of lung bacterial pathogens. | biological disease models can be difficult and costly to develop and use on a routine basis. particularly, in vivo lung infection models performed to study lung pathologies use to be laborious, demand a great time and commonly are associated with ethical issues. when infections in experimental animals are used, they need to be refined, defined, and validated for their intended purpose. therefore, alternative and easy to handle models of experimental infections are still needed to test the virule ... | 2015 | 25699030 |
| antimicrobial activity of gallium protoporphyrin ix against acinetobacter baumannii strains displaying different antibiotic resistance phenotypes. | a paucity of effective, currently available antibiotics and a lull in antibiotic development pose significant challenges for treatment of patients with multidrug-resistant (mdr) acinetobacter baumannii infections. thus, novel therapeutic strategies must be evaluated to meet the demands of treatment of these often life-threatening infections. accordingly, we examined the antibiotic activity of gallium protoporphyrin ix (ga-ppix) against a collection of a. baumannii strains, including nonmilitary ... | 2015 | 26416873 |
| phase-variable control of multiple phenotypes in acinetobacter baumannii strain ab5075. | acinetobacter baumannii strain ab5075 produces colonies with two opacity phenotypes, designated opaque and translucent. these phenotypes were unstable and opaque and translucent colony variants were observed to interconvert at high frequency, suggesting that a phase-variable mechanism was responsible. the frequency of phase variation both within colonies and in broth cultures increased in a cell density-dependent manner and was mediated by the accumulation of an extracellular factor. this factor ... | 2015 | 26013481 |
| reassessment of the listeria monocytogenes pan-genome reveals dynamic integration hotspots and mobile genetic elements as major components of the accessory genome. | listeria monocytogenes is an important food-borne pathogen and model organism for host-pathogen interaction, thus representing an invaluable target considering research on the forces governing the evolution of such microbes. the diversity of this species has not been exhaustively explored yet, as previous efforts have focused on analyses of serotypes primarily implicated in human listeriosis. we conducted complete genome sequencing of 11 strains employing 454 gs flx technology, thereby achieving ... | 2013 | 23339658 |
| joint transcriptional control of virulence and resistance to antibiotic and environmental stress in acinetobacter baumannii. | the increasing emergence of antibiotic-resistant bacterial pathogens represents a serious risk to human health and the entire health care system. many currently circulating strains of acinetobacter baumannii exhibit resistance to multiple antibiotics. a key limitation in combating a. baumannii is that our understanding of the molecular mechanisms underlying the pathogenesis of a. baumannii is lacking. to identify potential virulence determinants of a contemporary multidrug-resistant isolate of a ... | 2015 | 26556274 |
| identification of a new alcaligenes faecalis strain mor02 and assessment of its toxicity and pathogenicity to insects. | we report the isolation of a bacterium from galleria mellonella larva and its identification using genome sequencing and phylogenomic analysis. this bacterium was named alcaligenes faecalis strain mor02. microscopic analyses revealed that the bacteria are located in the esophagus and intestine of the nematodes steinernema feltiae, s. carpocapsae, and h. bacteriophora. using g. mellonella larvae as a model, when the larvae were injected with 24,000 cfu in their hemocoel, more than 96% mortality w ... | 2015 | 25667924 |
| identification and characterization of the insecticidal toxin "makes caterpillars floppy" in photorhabdus temperata m1021 using a cosmid library. | photorhabdus temperata is an entomopathogenic enterobacterium; it is a nematode symbiont that possesses pathogenicity islands involved in insect virulence. herein, we constructed a p. temperata m1021 cosmid library in escherichia coli xl1-blue mrf` and obtained 7.14 × 105 clones. however, only 1020 physiologically active clones were screened for insect virulence factors by injection of each e. coli cosmid clone into galleria mellonella and tenebrio molitor larvae. a single cosmid clone, ptc1015, ... | 2014 | 25014195 |
| in vitro and in vivo activities of tigecycline-colistin combination therapies against carbapenem-resistant enterobacteriaceae. | we assessed the activity of tigecycline (tgc) combined with colistin (col) against carbapenem-resistant enterobacteria. synergy occurred in vitro against the majority of isolates, with the exception of serratia marcescens. in a simple animal model (galleria mellonella), tgc-col was superior (p < 0.01) in treating escherichia coli, klebsiella pneumoniae, and enterobacter infections, including those with tgc-col resistance. clinical studies are needed to determine whether tgc-col regimens may be a ... | 2014 | 24687491 |
| effective immunosuppression with dexamethasone phosphate in the galleria mellonella larva infection model resulting in enhanced virulence of escherichia coli and klebsiella pneumoniae. | the aim was to evaluate whether immunosuppression with dexamethasone 21-phosphate could be applied to the galleria mellonella in vivo infection model. characterised clinical isolates of escherichia coli or klebsiella pneumoniae were employed, and g. mellonella larvae were infected with increasing doses of each strain to investigate virulence in vivo. virulence was then compared with larvae exposed to increasing doses of dexamethasone 21-phosphate. the effect of dexamethasone 21-phosphate on larv ... | 2016 | 26920133 |
| carbapenem-resistant klebsiella pneumoniae exhibit variability in capsular polysaccharide and capsule associated virulence traits. | novel therapies are urgently needed to treat carbapenem-resistant klebsiella pneumoniae (cr-kp)-mediated infection, which constitute a major health threat in the united states. in order to assess if it is feasible to develop anticapsular antibodies as a potential novel therapy, it is crucial to first systematically characterize capsular polysaccharide (cps) and virulence traits in these strains. | 2014 | 24634498 |
| cyp52x1, representing new cytochrome p450 subfamily, displays fatty acid hydroxylase activity and contributes to virulence and growth on insect cuticular substrates in entomopathogenic fungus beauveria bassiana. | infection of insects by the entomopathogenic fungus beauveria bassiana proceeds via attachment and penetration of the host cuticle. the outermost epicuticular layer or waxy layer of the insect represents a structure rich in lipids including abundant amounts of hydrocarbons and fatty acids. a member of a novel cytochrome p450 subfamily, cyp52x1, implicated in fatty acid assimilation by b. bassiana was characterized. b. bassiana targeted gene knockouts lacking bbcyp52x1 displayed reduced virulence ... | 2012 | 22393051 |
| expression of a toll signaling regulator serpin in a mycoinsecticide for increased virulence. | serpins are ubiquitously distributed serine protease inhibitors that covalently bind to target proteases to exert their activities. serpins regulate a wide range of activities, particularly those in which protease-mediated cascades are active. the drosophila melanogaster serpin spn43ac negatively controls the toll pathway that is activated in response to fungal infection. the entomopathogenic fungus beauveria bassiana offers an environmentally friendly alternative to chemical pesticides for inse ... | 0 | 24837378 |
| haemocoel injection of pira1b1 to galleria mellonella larvae leads to disruption of the haemocyte immune functions. | the bacterium photorhabdus luminescens produces a number of insecticidal proteins to kill its larval prey. in this study, we cloned the gene coding for a binary toxin pira1b1 and purified the recombinant protein using affinity chromatography combined with desalination technology. furthermore, the cytotoxicity of the recombinant protein against the haemocytes of galleria mellonella larvae was investigated. we found that the protein had haemocoel insecticidal activity against g. mellonella with an ... | 2016 | 27734915 |
| transcript abundance of photorhabdus insect-related (pir) toxin in manduca sexta and galleria mellonella infections. | in this study, we assessed pirab toxin transcription in photorhabdus luminescens laumondii (strain tt01) (enterobacteriaceae) by comparing mrna abundance under in vivo and in vitro conditions. in vivo assays considered both natural and forced infections with two lepidopteran hosts: galleria mellonella and manduca sexta. three portals of entry were utilized for the forced infection assays: (a) integument; (b) the digestive route (via mouth and anus); and (c) the tracheal route (via spiracles). we ... | 2016 | 27690103 |
| pyrokinin β-neuropeptide affects necrophoretic behavior in fire ants (s. invicta), and expression of β-np in a mycoinsecticide increases its virulence. | fire ants are one of the world's most damaging invasive pests, with few means for their effective control. although ecologically friendly alternatives to chemical pesticides such as the insecticidal fungus beauveria bassiana have been suggested for the control of fire ant populations, their use has been limited due to the low virulence of the fungus and the length of time it takes to kill its target. we present a means of increasing the virulence of the fungal agent by expressing a fire ant neur ... | 2012 | 22238569 |
| ninab combines carotenoid oxygenase and retinoid isomerase activity in a single polypeptide. | in animals, successful production of the visual chromophore (11-cis-retinal or derivatives thereof such as 11-cis-3-hydroxy-retinal) is essential for photoreceptor cell function and survival. these carotenoid-derived compounds must combine with a protein moiety (the opsin) to establish functional visual pigments. evidence from cell culture systems has implicated that the retinal pigment epithelium protein of 65 kda (rpe65) is the long-sought all-trans to 11-cis retinoid isomerase. rpe65 is struc ... | 2008 | 19020100 |
| development and immunity-related micrornas of the lepidopteran model host galleria mellonella. | micrornas (mirnas) are small non-coding rnas that act as key players in the post-transcriptional regulation of protein synthesis. although little is known about their role in complex physiological processes such as development and immunity, our knowledge is expanding rapidly, thanks to the use of model systems. the larvae of the greater wax moth galleria mellonella are now established as model hosts for pathogens that infect insects or humans. to build on our previously-reported comprehensive g. ... | 2014 | 25149864 |
| drosophila and galleria insect model hosts: new tools for the study of fungal virulence, pharmacology and immunology. | over recent years we have witnessed the emergence of several non-vertebrate mini-hosts as alternative pathosystems for the study of fungal disease. these heterologous organisms have unique advantages, as they are economical, ethically expedient, and facile to use. hence, they are amenable to high-throughput screening studies of fungal genomes for identification of novel virulence genes and of chemical libraries for discovery of new antifungal compounds. in addition, because they have evolutionar ... | 0 | 22186764 |
| two membrane-associated regions within the nodamura virus rna-dependent rna polymerase are critical for both mitochondrial localization and rna replication. | viruses with positive-strand rna genomes amplify their genomes in replication complexes associated with cellular membranes. little is known about the mechanism of replication complex formation in cells infected with nodamura virus. this virus is unique in its ability to lethally infect both mammals and insects. in mice and in larvae of the greater wax moth (galleria mellonella), nodamura virus-infected muscle cells exhibit mitochondrial aggregation and membrane rearrangement, leading to disorgan ... | 2014 | 24696464 |
| evaluation of galleria mellonella larvae for studying the virulence of streptococcus suis. | streptococcus suis is an encapsulated gram-positive bacterium and the leading cause of sepsis and meningitis in young pigs, resulting in considerable economic losses in the porcine industry. s. suis is considered an emerging zoonotic agent with increasing numbers of human cases over the last years. in the environment, both avirulent and virulent strains occur in pigs, with no evidence for consistent adapatation of virulent strains to the human host. currently, there is an urgent need for a conve ... | 2016 | 27978817 |
| morphology and its underlying genetic regulation impact the interaction between cryptococcus neoformans and its hosts. | cryptococcus neoformans is a fungus that causes the majority of fatal cryptococcal meningitis cases worldwide. this pathogen is capable of assuming different morphotypes: yeast, pseudohypha, and hypha. the yeast form is the most common cell type observed clinically. the hyphal and pseudohyphal forms are rarely observed in the clinical setting and are considered attenuated in virulence. however, as a ubiquitous environmental pathogen, cryptococcus interacts with various organisms, and it is known ... | 2015 | 25841056 |
| fungal virulence in a lepidopteran model is an emergent property with deterministic features. | abstract virulence has been proposed to be an emergent property, which by definition implies that it is not reducible to its components, but this application of a philosophical concept to the host-microbe interaction has not been experimentally tested. the goals of our study were to analyze the correlation of the phenotype with the ability to cause disease and to determine the dynamics of an experimental cryptococcal infection in galleria mellonella and acanthamoeba castellanii. by studying the ... | 2013 | 23631914 |
| 1,2,4-triazolidine-3-thiones as narrow spectrum antibiotics against multidrug-resistant acinetobacter baumannii. | with only two new classes of antibiotics developed in the last 40 years, novel antibiotics are desperately needed to combat the growing problem of multidrug-resistant and extensively drug resistant bacteria, particularly gram-negative bacteria. described in this letter is the synthesis and antibiotic activity of 1,2,4-triazolidine-3-thiones as narrow spectrum antibiotics. optimization of the 1,2,4-triazolidine-3-thione scaffold identified a small molecule with potent antibiotic activity against ... | 2017 | 28105270 |
| modeling acinetobacter baumannii wound infections: the critical role of iron. | acinetobacter baumannii has emerged as an increasingly important and successful opportunistic human pathogen due to its ability to withstand harsh environmental conditions, its characteristic virulence factors, and quick adaptability to stress. | 2017 | 28030490 |
| repurposing the anticancer drug mitomycin c for the treatment of persistent acinetobacter baumannii infections. | acinetobacter baumannii is an emergent opportunistic bacterial pathogen responsible for recalcitrant infections owing to its high intrinsic tolerance to most antibiotics; therefore, suitable strategies to treat these infections are needed. one plausible approach is the repurposing of drugs that are already in use. among them, anticancer drugs may be especially useful due their cytotoxic activities and ample similarities between bacterial infections and growing tumours. in this work, the effectiv ... | 2017 | 27939675 |
| iron-regulated phospholipase c activity contributes to the cytolytic activity and virulence of acinetobacter baumannii. | acinetobacter baumannii is an opportunistic gram-negative pathogen that causes a wide range of infections including pneumonia, septicemia, necrotizing fasciitis and severe wound and urinary tract infections. analysis of a. baumannii representative strains grown in chelex 100-treated medium for hemolytic activity demonstrated that this pathogen is increasingly hemolytic to sheep, human and horse erythrocytes, which interestingly contain increasing amounts of phosphatidylcholine in their membranes ... | 2016 | 27875572 |
| multiple roles for a novel rnd-type efflux system in acinetobacter baumannii ab5075. | colony opacity phase variation in acinetobacter baumannii strain ab5075 is regulated by a reversible high-frequency switch. transposon mutagenesis was used to generate mutations that decreased the opaque to translucent switch and a gene encoding a predicted periplasmic membrane fusion component of a resistance-nodulation-cell division (rnd)-type efflux system was isolated. this gene was designated arpa and immediately downstream was a gene designated arpb that encodes a predicted membrane transp ... | 2016 | 27762102 |
| personalized therapeutic cocktail of wild environmental phages rescues mice from acinetobacter baumannii wound infections. | multidrug-resistant bacterial pathogens are an increasing threat to public health, and lytic bacteriophages have reemerged as a potential therapeutic option. in this work, we isolated and assembled a five-member cocktail of wild phages against acinetobacter baumannii and demonstrated therapeutic efficacy in a mouse full-thickness dorsal infected wound model. the cocktail lowers the bioburden in the wound, prevents the spread of infection and necrosis to surrounding tissue, and decreases infectio ... | 2016 | 27431214 |
| combination therapy with polymyxin b and netropsin against clinical isolates of multidrug-resistant acinetobacter baumannii. | polymyxins are last-resort antibiotics for treating infections of gram-negative bacteria. the recent emergence of polymyxin-resistant bacteria, however, urgently demands clinical optimisation of polymyxin use to minimise further evolution of resistance. in this study we developed a novel combination therapy using minimal concentrations of polymyxin b. after large-scale screening of streptomyces secondary metabolites, we identified a reliable polymixin synergist and confirmed as netropsin using h ... | 2016 | 27306928 |
| the acinetobacter baumannii two-component system aders regulates genes required for multidrug efflux, biofilm formation, and virulence in a strain-specific manner. | the opportunistic pathogen acinetobacter baumannii is able to persist in the environment and is often multidrug resistant (mdr), causing difficulties in the treatment of infections. here, we show that the two-component system aders, which regulates the production of the adeabc multidrug resistance efflux pump, is required for the formation of a protective biofilm in an ex vivo porcine mucosal model, which mimics a natural infection of the human epithelium. interestingly, deletion of adeb impacte ... | 2016 | 27094331 |
| characterization of surface antigen protein 1 (sura1) from acinetobacter baumannii and its role in virulence and fitness. | acinetobacter baumannii is a gram-negative bacillus that causes nosocomial infections, such as bacteremia, pneumonia, and meningitis and urinary tract and wound infections. in the present study, the surface antigen protein 1 (sura1) gene of a. baumannii strain ccggd201101 was identified, cloned and expressed, and then its roles in fitness and virulence were investigated. virulence was observed in the human lung cancer cell lines a549 and hep-2 at one week after treatment with recombinant sura1. ... | 2016 | 27016767 |
| katg and kate confer acinetobacter resistance to hydrogen peroxide but sensitize bacteria to killing by phagocytic respiratory burst. | catalase catalyzes the degradation of h2o2. acinetobacter species have four predicted catalase genes, kata, kate, katg, and katx. the aims of the present study seek to determine which catalase(s) plays a predominant role in determining the resistance to h2o2, and to assess the role of catalase in acinetobacter virulence. | 2016 | 26860891 |
| activity of levofloxacin in combination with colistin against acinetobacter baumannii: in vitro and in a galleria mellonella model. | treatment of acinetobacter baumannii infections is challenging owing to widespread multidrug-resistant a. baumannii (mdr-ab) and the lack of novel agents. although recent data suggest that levofloxacin (lvx) may have unique activity against mdr-ab in combination with colistin (cst), further preclinical work is needed. | 2015 | 26725481 |
| in vivo activity of vancomycin combined with colistin against multidrug-resistant strains of acinetobacter baumannii in a galleria mellonella model. | with increasing antibiotic resistance, the selection of effective treatment of a. baumannii infections is particularly challenging. | 2016 | 26503239 |
| differential role of the t6ss in acinetobacter baumannii virulence. | gram-negative bacteria, such as acinetobacter baumannii, are an increasing burden in hospitals worldwide with an alarming spread of multi-drug resistant (mdr) strains. herein, we compared a type strain (atcc17978), a non-clinical isolate (dsm30011) and mdr strains of a. baumannii implicated in hospital outbreaks (ab242, ab244 and ab825), revealing distinct patterns of type vi secretion system (t6ss) functionality. the t6ss genomic locus is present and was actively transcribed in all of the above ... | 2015 | 26401654 |
| retention of virulence following adaptation to colistin in acinetobacter baumannii reflects the mechanism of resistance. | colistin resistance in acinetobacter baumannii has been associated with loss of virulence and a negative impact on isolate selection. in this study, exposure of clinical isolates to suboptimal concentrations of colistin was used to explore the capacity to develop resistance by diverse mechanisms, and whether acquired resistance always reduces fitness and virulence. | 2015 | 25904728 |
| vancomycin protects against acinetobacter baumannii infection in a galleria mellonella model. | | 2015 | 25746598 |
| in vivo activity of daptomycin/colistin combination therapy in a galleria mellonella model of acinetobacter baumannii infection. | antimicrobial treatment of multidrug-resistant acinetobacter baumannii (mdr-ab) infections continues to pose significant challenges. with limited options, clinicians have been pushed towards using unorthodox combinations of licensed antibiotics. although daptomycin/colistin combination appears to be a promising treatment option based on in vitro data, further preclinical work is needed. in this study, the a. baumannii-galleria mellonella system was employed to study the in vivo efficacy of this ... | 2015 | 25440154 |
| ab5075, a highly virulent isolate of acinetobacter baumannii, as a model strain for the evaluation of pathogenesis and antimicrobial treatments. | acinetobacter baumannii is recognized as an emerging bacterial pathogen because of traits such as prolonged survival in a desiccated state, effective nosocomial transmission, and an inherent ability to acquire antibiotic resistance genes. a pressing need in the field of a. baumannii research is a suitable model strain that is representative of current clinical isolates, is highly virulent in established animal models, and can be genetically manipulated. to identify a suitable strain, a genetical ... | 2014 | 24865555 |
| pathogenicity of clinical acinetobacter baumannii isolates in a galleria mellonella host model according to bla(oxa-40) gene and epidemiological outbreak status. | clinical studies have suggested that blaoxa-40-positive acinetobacter baumannii isolates are associated with poor patient outcomes; however, reasons for unfavorable outcomes are difficult to discern in clinical studies. the objective of this study was to assess the virulence of carbapenem-resistant a. baumannii according to blaoxa-40 and epidemiological outbreak status in a galleria mellonella model. eight isolates of a. baumannii were studied. nonoutbreak isolates and blaoxa-40-negative isolate ... | 2014 | 24295983 |
| in vivo efficacy of telavancin/colistin combination therapy in a galleria mellonella model of acinetobacter baumannii infection. | treatment of acinetobacter baumannii infections is challenging owing to widespread multidrug resistance and the lack of novel agents. there is now considerable interest in the potential of unorthodox combination therapies such as colistin and glycopeptides (e.g. vancomycin and teicoplanin), since potent synergy can be demonstrated in vitro. a simple invertebrate model (galleria mellonella) has been developed to assess the in vivo activity of antimicrobial therapies and was used to investigate th ... | 2013 | 23312607 |
| surface-associated motility, a common trait of clinical isolates of acinetobacter baumannii, depends on 1,3-diaminopropane. | while flagella-independent motility has long been described in representatives of the genus acinetobacter, the mechanism of motility remains ambiguous. acinetobacter baumannii, a nosocomial pathogen appearing increasingly multidrug-resistant, may profit from motility during infection or while persisting in the hospital environment. however, data on the frequency of motility skills among clinical a. baumannii isolates is scarce. we have screened a collection of 83 clinical a. baumannii isolates o ... | 2012 | 22560766 |
| galleria mellonella is an effective model to study actinobacillus pleuropneumoniae infection. | actinobacillus pleuropneumoniae is responsible for swine pleuropneumonia, a respiratory disease that causes significant global economic loss. its virulence depends on many factors, such as capsular polysaccharides, rtx toxins and iron-acquisition systems. analysis of virulence may require easy-to-use models that approximate mammalian infection and avoid ethical issues. here, we investigate the potential use of the wax moth galleria mellonella as an informative model for a. pleuropneumoniae infec ... | 2015 | 25414045 |
| protease inhibitor from insect silk-activities of derivatives expressed in vitro and in transgenic potato. | several recombinant derivatives of serine protease inhibitor called silk protease inhibitor 2 (spi2), which is a silk component in galleria mellonella (lepidoptera, insecta), were prepared in the expression vector pichia pastoris. both the native and the recombinant protease inhibitors were highly active against subtilisin and proteinase k. the synthetic spi2 gene with ala codon in the p1 position was fused with mgfp-5 to facilitate detection of the transgene and its protein product. a construct ... | 2013 | 23824530 |
| exoproteome of aspergillus flavus corneal isolates and saprophytes: identification of proteoforms of an oversecreted alkaline protease. | aspergillus flavus infects the human eye leading to keratitis. extracellular proteins, the earliest proteins that come in contact with the host and virulence related exoproteins, were identified in the fungus isolated from infected cornea. virulence of the corneal isolates was tested in the galleria mellonella larvae model and those isolates showing higher virulence were taken for subsequent exoproteome analysis. high resolution two-dimensional electrophoresis and mass spectrometry were used to ... | 2015 | 25497218 |
| functional investigation of iron-responsive microsomal proteins, including mirc, in aspergillus fumigatus. | the functionality of many microsome-associated proteins which exhibit altered abundance in response to iron limitation in aspergillus fumigatus is unknown. here, we generate and characterize eight gene deletion strains, and of most significance reveal that mirc (afua_2g05730) contributes to the maintenance of intracellular siderophore [ferricrocin (fc)] levels, augments conidiation, confers protection against oxidative stress, exhibits an intracellular localization and contributes to fungal viru ... | 2017 | 28367141 |
| the er-mitochondria encounter structure contributes to hyphal growth, mitochondrial morphology and virulence of the pathogenic mold aspergillus fumigatus. | aspergillus fumigatus is an opportunistic fungal pathogen and the primary causative species of invasive aspergillosis, a systemic disease associated with high mortality rates. treatment of invasive fungal infection relies on a very limited number of antifungal drug classes. in order to extend the spectrum of antifungal drugs novel target structures have to be identified. the er-mitochondria encounter structure (ermes), a recently discovered tether that links mitochondria and endoplasmic reticulu ... | 2017 | 27939177 |
| genome-wide transcriptome analysis of aspergillus fumigatus exposed to osmotic stress reveals regulators of osmotic and cell wall stresses that are saka(hog1) and mpkc dependent. | invasive aspergillosis is predominantly caused by aspergillus fumigatus, and adaptations to stresses experienced within the human host are a prerequisite for the survival and virulence strategies of the pathogen. the central signal transduction pathway operating during hyperosmotic stress is the high osmolarity glycerol mitogen-activated protein kinase cascade. a. fumigatus mpkc and saka, orthologues of the saccharomyces cerevisiae hog1p, constitute the primary regulator of the hyperosmotic stre ... | 2017 | 27706915 |
| characterization of gprk encoding a putative hybrid g-protein-coupled receptor in aspergillus fumigatus. | the g-protein-coupled receptor (gpcr) family represents the largest and most varied collection of membrane embedded proteins that are sensitized by ligand binding and interact with heterotrimeric g proteins. despite their presumed critical roles in fungal biology, the functions of the gpcr family members in the opportunistic human pathogen aspergillus fumigatus are largely unknown, as only two (gprc and gprd) of the 15 predicted gpcrs have been studied. here, we characterize the gprk gene, which ... | 2016 | 27584150 |
| distinct roles of myosins in aspergillus fumigatus hyphal growth and pathogenesis. | myosins are a family of actin-based motor proteins found in many organisms and are categorized into classes based on their structures. class ii and v myosins are known to be important for critical cellular processes, including cytokinesis, endocytosis, exocytosis, and organelle trafficking, in the model fungi saccharomyces cerevisiae and aspergillus nidulans however, the roles of myosins in the growth and virulence of the pathogen aspergillus fumigatus are unknown. we constructed single- and dou ... | 2016 | 26953327 |
| identification and characterization of haemofungin, a novel antifungal compound that inhibits the final step of haem biosynthesis. | during recent decades, the number of invasive fungal infections among immunosuppressed patients has increased significantly, whereas the number of effective systemic antifungal drugs remains low and unsatisfactory. the aim of this study was to characterize a novel antifungal compound, cw-8/haemofungin, which we previously identified in a screen for compounds affecting fungal cell wall integrity. | 2016 | 26747101 |
| in vivo efficacy of voriconazole and posaconazole therapy in a novel invertebrate model of aspergillus fumigatus infection. | the emergence of azole resistance in aspergillus fumigatus is a clinically important issue in the management of invasive aspergillosis as it could limit therapeutic options. accurate measurement of in vitro antifungal activity in terms of minimum inhibitory concentration (mic) is considered of clinical relevance and often gives useful therapeutic information for physicians. however, the lack of in vitro-in vivo correlation is frequent and the observed in vitro phenotype does not always correlate ... | 2015 | 26358971 |
| an alternative host model of a mixed fungal infection by azole susceptible and resistant aspergillus spp strains. | aspergillus fumigatus is the most common mold involved in human infections. however, the number of non-fumigatus species able to cause disease is continuously increasing. among them, aspergillus lentulus is reported in hematological and cystic fibrosis patients and in those treated with corticosteroids. a. lentulus differs from a. fumigatus in some clinically relevant aspects such as virulence and antifungal susceptibility, showing high mics to most antifungals. previous studies proved that a. l ... | 2015 | 26065322 |
| the aspergillus fumigatus septins play pleiotropic roles in septation, conidiation, and cell wall stress, but are dispensable for virulence. | septins are a conserved family of gtpases that regulate important cellular processes such as cell wall integrity, and septation in fungi. the requirement of septins for virulence has been demonstrated in the human pathogenic yeasts candida albicans and cryptococcus neoformans, as well as the plant pathogen magnaporthe oryzae. aspergillus spp. contains five genes encoding for septins (aspa-e). while the importance of septins aspa, aspb, aspc, and aspe for growth and conidiation has been elucidate ... | 2015 | 26051489 |
| amca-a putative mitochondrial ornithine transporter supporting fungal siderophore biosynthesis. | iron is an essential nutrient required for a wide range of cellular processes. the opportunistic fungal pathogen aspergillus fumigatus employs low-molecular mass iron-specific chelators, termed siderophores, for uptake, storage and intracellular iron distribution, which play a crucial role in the pathogenicity of this fungus. siderophore biosynthesis (sb) depends on coordination with the supply of its precursor ornithine, produced mitochondrially from glutamate or cytosolically via hydrolysis of ... | 2015 | 25904899 |
| aspergillus fumigatus mycovirus causes mild hypervirulent effect on pathogenicity when tested on galleria mellonella. | mycoviruses are a specific group of viruses that naturally infect and replicate in fungi. the importance of mycoviruses was revealed after their effects were identified not only in economically important fungi but also in the human pathogenic fungus aspergillus fumigatus. the latter was shown recently to harbor at least three different types of mycoviruses including a chrysovirus, a partitivirus and an as yet uncharacterized virus. assessment of virulence in the presence and absence of mycovirus ... | 2015 | 25626171 |
| calcium signaling mediates antifungal activity of triazole drugs in the aspergilli. | azoles are widely applied and largely effective as antifungals; however, the increasing prevalence of clinically resistant isolates has yet to be matched by approaches to improve the efficacy of antimicrobial therapy. in this study, using the model fungus aspergillus nidulans and one of the most common human pathogen aspergillus fumigatus as research materials, we present the evidence that calcium signaling is involved in the azole-antifungals-induced stress-response reactions. in normal media, ... | 2015 | 25554700 |
| role of gliotoxin in the symbiotic and pathogenic interactions of trichoderma virens. | using a gene disruption strategy, we generated mutants in the glip locus of the plant-beneficial fungus trichoderma virens that were no longer capable of producing gliotoxin. phenotypic assays demonstrated that the glip-disrupted mutants grew faster, were more sensitive to oxidative stress and exhibited a sparse colony edge compared with the wt strain. in a plate confrontation assay, the mutants deficient in gliotoxin production were ineffective as mycoparasites against the oomycete, pythium ult ... | 2014 | 25082950 |
| the mtfa transcription factor gene controls morphogenesis, gliotoxin production, and virulence in the opportunistic human pathogen aspergillus fumigatus. | aspergillus fumigatus is the leading causative agent of invasive aspergillosis (ia). the number of cases is on the rise, with mortality rates as high as 90% among immunocompromised patients. molecular genetic studies in a. fumigatus could provide novel targets to potentially set the basis for antifungal therapies. in the current study, we investigated the role of the transcription factor gene mtfa in a. fumigatus. our results revealed that mtfa plays a role in the growth and development of the f ... | 2014 | 24728192 |
| an invertebrate model to evaluate virulence in aspergillus fumigatus: the role of azole resistance. | the impact of different mutations in the aspergillus fumigatus ergosterol biosynthesis pathway on pathogenesis has been evaluated using a simple invertebrate mini host, the caterpillar galleria mellonella. a set of strains that includes clinical isolates and isogenic mutants with mutations at the cyp51a gene conferring azole resistance were studied. all strains demonstrated a similar in vitro growth pattern and are equally virulent against the insect larvae. these results suggest that in a. fumi ... | 2014 | 24577012 |
| thermal and physical stresses induce a short-term immune priming effect in galleria mellonella larvae. | exposure of larvae of galleria mellonella larvae to mild physical (i.e. shaking) or thermal stress for 24h increased their ability to survive infection with aspergillus fumigatus conidia however larvae stressed in a similar manner but incubated for 72h prior to infection showed no elevation in their resistance to infection with a. fumigatus. stressed larvae demonstrated an elevated haemocyte density 24h after initiation of the stress event but this declined at 48 and 72h. larval proteins such as ... | 2014 | 24561359 |
| genetic and virulence variation in an environmental population of the opportunistic pathogen aspergillus fumigatus. | environmental populations of the opportunistic pathogen aspergillus fumigatus have been shown to be genotypically diverse and to contain a range of isolates with varying pathogenic potential. in this study, we combined two rapd primers to investigate the genetic diversity of environmental isolates from manchester collected monthly over 1 year alongside dublin environmental isolates and clinical isolates from patients. rapd analysis revealed a diverse genotype, but with three major clinical isola ... | 2014 | 24464798 |
| laccases involved in 1,8-dihydroxynaphthalene melanin biosynthesis in aspergillus fumigatus are regulated by developmental factors and copper homeostasis. | aspergillus fumigatus produces heavily melanized infectious conidia. the conidial melanin is associated with fungal virulence and resistance to various environmental stresses. this 1,8-dihydroxynaphthalene (dhn) melanin is synthesized by enzymes encoded in a gene cluster in a. fumigatus, including two laccases, abr1 and abr2. although this gene cluster is not conserved in all aspergilli, laccases are critical for melanization in all species examined. here we show that the expression of a. fumiga ... | 2013 | 24123270 |
| characterization of the link between ornithine, arginine, polyamine and siderophore metabolism in aspergillus fumigatus. | the opportunistic fungal pathogen aspergillus fumigatus produces siderophores for uptake and storage of iron, which is essential for its virulence. the main precursor of siderophore biosynthesis (sb), ornithine, can be produced from glutamate in the mitochondria or by cytosolic hydrolysis of ornithine-derived arginine. here, we studied the impact of mitochondrial versus cytosolic ornithine biosynthesis on sb by comparison of the arginine auxotrophic mutants δargef and δargb, which lack and posse ... | 2013 | 23825660 |
| deletion of the sec4 homolog srga from aspergillus fumigatus is associated with an impaired stress response, attenuated virulence and phenotypic heterogeneity. | small gtpases of the rab family are master regulators of membrane trafficking, responsible for coordinating the sorting, packaging and delivery of membrane-bound vesicles to specific sites within eukaryotic cells. the contribution of these proteins to the biology of the human pathogenic fungus aspergillus fumigatus has not been explored. in this study, we characterized the srga gene, encoding a rab gtpase closely related to sec4. we found that a gfp-srga fusion protein accumulated preferentially ... | 2013 | 23785510 |
| nosa, a transcription factor important in aspergillus fumigatus stress and developmental response, rescues the germination defect of a laea deletion. | aspergillus fumigatus is an increasingly serious pathogen of immunocompromised patients, causing the often fatal disease invasive aspergillosis (ia). one a. fumigatus virulence determinant of ia is laea, a conserved virulence factor in pathogenic fungi. to further understand the role of laea in ia, the expression profile of δlaea was compared to wild type, and several transcription factors were found significantly misregulated by laea loss. one of the transcription factors up-regulated over 4-fo ... | 2012 | 23022264 |
| aspergillus fumigatus calcineurin interacts with a nucleoside diphosphate kinase. | the ca(2+)-calcineurin pathway affects virulence and morphogenesis in filamentous fungi. here, we identified 37 cala-interacting proteins that interact with the catalytic subunit of calcineurin (cala) in aspergillus fumigatus, including the nucleoside diphosphate kinase (swoh). the in vivo interaction between cala and swoh was validated by bimolecular fluorescence complementation. a. fumigatus swoh is an essential gene. therefore, a temperature-sensitive conditional mutant strain with a point mu ... | 2012 | 22634424 |
| functional characterization of the aspergillus nidulans glucosylceramide pathway reveals that lcb δ8-desaturation and c9-methylation are relevant to filamentous growth, lipid raft localization and psd1 defensin activity. | c8-desaturated and c9-methylated glucosylceramide (glccer) is a fungal-specific sphingolipid that plays an important role in the growth and virulence of many species. in this work, we investigated the contribution of aspergillus nidulans sphingolipid δ8-desaturase (sdea), sphingolipid c9-methyltransferases (smta/smtb) and glucosylceramide synthase (gcsa) to fungal phenotypes, sensitivity to psd1 defensin and galleria mellonella virulence. we showed that δsdea accumulated c8-saturated and unmethy ... | 2016 | 27479571 |
| identification and characterization of a novel family of selective antifungal compounds (canbefs) that interfere with fungal protein synthesis. | invasive mycotic infections have become more common during recent decades, posing an increasing threat to public health. however, despite the growing needs, treatments for invasive fungal infections remain unsatisfactory and are limited to a small number of antifungals. the aim of this study was to identify novel fungal cell wall inhibitors from a library of small chemical compounds using a conditional protein kinase c (pkc)-expressing strain of aspergillus nidulans sensitive to cell wall-active ... | 2015 | 26149982 |
| synthesis of novel tetrazole derivatives and evaluation of their antifungal activity. | with the appearance of the antifungal resistance, novel antifungal agents need to be identified. in this context new 2,5-disubstituted tetrazole derivatives containing benzothiazole, benzoxazole or phenylsulfonyl moiety were synthesized by n-alkylation of aryltetrazole with 2-[(3-chloropropyl)sulfanyl]-1,3-benzothiazole or 2-[(3-chloropropyl)sulfanyl]-1,3-benzoxazole and michael-type addition of aryltetrazole to phenyl vinyl sulfone. the chemical structures of the synthesized compounds were conf ... | 2016 | 27745991 |
| geographically predominant genotypes of aspergillus terreus species complex in austria: s microsatellite typing study. | aspergillus terreus species complex is recognized as a frequent agent of invasive aspergillosis in tyrol. the reason for this specific epidemiological situation is unclear. aspergillus terreus strains isolated from environmental and clinical sources were genotyped using a novel panel of short tandem repeats and were evaluated for virulence. three major endemic genotypes collected from the inn region and its side valleys were found to cause the majority of invasive a. terreus infections. all of t ... | 2016 | 26577144 |
| [using galleria mellonella as an in vivo model to study the virulence of some bacterial and fungal agents]. | non-vertebrate hosts, such as galleria mellonella, namely wax moth, have been used to study microbial virulence and host defense. this organism has advantages as it is economical, ethically expedient and easy to handle. here we describe an experimental in vivo study using the larvae of galleria mellonella infected with some bacterial and fungal pathogens. in this study, extended-spectrum beta-lactamase (esbl) producing and non-producing escherichia coli, klebsiella pneumoniae and pseudomonas aer ... | 2015 | 26313278 |