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Sample records for wild-type strain pao1

  1. Pseudomonas aeruginosa PAO1 exopolysaccharides are important for mixed species biofilm community development and stress tolerance

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    Saravanan ePeriasamy

    2015-08-01

    Full Text Available Pseudomonas aeruginosa PAO1 produces three polysaccharides, alginate, Psl and Pel that play distinct roles in attachment and biofilm formation for monospecies biofilms. Considerably less is known about their role in the development of mixed species biofilm communities. This study has investigated the roles of alginate, Psl and Pel during biofilm formation of P. aeruginosa in a defined and experimentally informative mixed species biofilm community, consisting of P. aeruginosa, Pseudomonas protegens and Klebsiella pneumoniae. Loss of the Psl polysaccharide had the biggest impact on the integration of P. aeruginosa in the mixed species biofilms, where the percent composition of the psl mutant was significantly lower (0.06% than its wild-type parent (2.44%. In contrast, loss of the Pel polysaccharide had no impact on mixed species biofilm development. Loss of alginate or its overproduction resulted in P. aeruginosa representing 8.4% and 18.11%, respectively, of the mixed species biofilm. Dual species biofilms of P. aeruginosa and K. pneumoniae were not affected by loss of alginate, Pel or Psl, while the mucoid P. aeruginosa strain achieved a greater biomass than its parent strain. When P. aeruginosa was grown with P. protegens, loss of the Pel or alginate polysaccharides resulted in biofilms that were not significantly different from biofilms formed by the wild-type PAO1. In contrast, overproduction of alginate resulted in biofilms that were comprised of 35-40% of P. aeruginosa, which was significantly higher than the wild-type (5-20%. Loss of the Psl polysaccharide significantly reduced the percentage composition of P. aeruginosa in dual species biofilms with P. protegens (<1%. Loss of the Psl polysaccharide significantly disrupted the communal stress resistance of the three species biofilms. Thus, the polysaccharide composition of an individual species significantly impacts mixed species biofilm development and the emergent properties of such

  2. Genome Sequences of Three Vaccine Strains and Two Wild-Type Canine Distemper Virus Strains from a Recent Disease Outbreak in South Africa.

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    Loots, Angelika K; Du Plessis, Morné; Dalton, Desiré Lee; Mitchell, Emily; Venter, Estelle H

    2017-07-06

    Canine distemper virus causes global multihost infectious disease. This report details complete genome sequences of three vaccine and two new wild-type strains. The wild-type strains belong to the South African lineage, and all three vaccine strains to the America 1 lineage. This constitutes the first genomic sequences of this virus from South Africa. Copyright © 2017 Loots et al.

  3. Comparative metabolic profiling of mce1 operon mutant vs wild-type Mycobacterium tuberculosis strains.

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    Queiroz, Adriano; Medina-Cleghorn, Daniel; Marjanovic, Olivera; Nomura, Daniel K; Riley, Lee W

    2015-11-01

    Mycobacterium tuberculosis disrupted in a 13-gene operon (mce1) accumulates free mycolic acids (FM) in its cell wall and causes accelerated death in mice. Here, to more comprehensively analyze differences in their cell wall lipid composition, we used an untargeted metabolomics approach to compare the lipid profiles of wild-type and mce1 operon mutant strains. By liquid chromatography-mass spectrometry, we identified >400 distinct lipids significantly altered in the mce1 mutant compared to wild type. These lipids included decreased levels of saccharolipids and glycerophospholipids, and increased levels of alpha-, methoxy- and keto mycolic acids (MA), and hydroxyphthioceranic acid. The mutant showed reduced expression of mmpL8, mmpL10, stf0, pks2 and papA2 genes involved in transport and metabolism of lipids recognized to induce proinflammatory response; these lipids were found to be decreased in the mutant. In contrast, the transcripts of mmpL3, fasI, kasA, kasB, acpM and RV3451 involved in MA transport and metabolism increased; MA inhibits inflammatory response in macrophages. Since the mce1 operon is known to be regulated in intracellular M. tuberculosis, we speculate that the differences we observed in cell wall lipid metabolism and composition may affect host response to M. tuberculosis infection and determine the clinical outcome of such an infection. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  4. Adhesion inhibition of F1C-fimbriated Escherichia coli and Pseudomonas aeruginosa PAK and PAO by multivalent carbohydrate ligands.

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    Autar, Reshma; Khan, A Salam; Schad, Matthias; Hacker, Jörg; Liskamp, Rob M J; Pieters, Roland J

    2003-12-05

    In order to evaluate their inhibition of bacterial adhesion, the carbohydrate sequences GalNAcbeta1-->4Gal and GalNAcbeta1-->4Galbeta1-->4Glc were synthesized. The disaccharide was conjugated to dendrons based on the 3,5-di-(2-aminoethoxy)-benzoic acid branching unit to yield di- and tetravalent versions of these compounds. A divalent compound was also prepared that had significantly longer spacer arms. Relevant monovalent compounds were prepared for comparison. Their anti-adhesion properties against F1C-fimbriated uropathogenic Escherichia coli were evaluated in an ELISA-type assay by using a recombinant strain and also by using Pseudomonas aeruginosa strains PAO and PAK. Adhesion inhibition was observed in all cases, and multivalency effects of up to one order of magnitude were observed. The combination of spacer and multivalency effects led to a 38-fold increase in the potency of a divalent inhibitor with long spacer arms towards the PAO strain when compared with the free carbohydrate.

  5. ELECTROPHORETIC MOBILITIES OF ESCHERICHIA COLI 0157:H7 AND WILD-TYPE ESCHERICHIA COLI STRAINS

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    The electrophoretic mobility (EPM) of a number of human-virulent and "wild-type" Escherichia coli strains in phosphate buffered water was measured. The impact of pH, ionic strength, cation type (valence) and concentration, and bacterial strain on the EPM was investigated. Resul...

  6. Feeding behaviour of Caenorhabditis elegans is an indicator of Pseudomonas aeruginosa PAO1 virulence

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    Shawn Lewenza

    2014-08-01

    Full Text Available Caenorhabditis elegans is commonly used as an infection model for pathogenesis studies in Pseudomonas aeruginosa. The standard virulence assays rely on the slow and fast killing or paralysis of nematodes but here we developed a behaviour assay to monitor the preferred bacterial food sources of C. elegans. We monitored the food preferences of nematodes fed the wild type PAO1 and mutants in the type III secretion (T3S system, which is a conserved mechanism to inject secreted effectors into the host cell cytosol. A ΔexsEΔpscD mutant defective for type III secretion served as a preferred food source, while an ΔexsE mutant that overexpresses the T3S effectors was avoided. Both food sources were ingested and observed in the gastrointestinal tract. Using the slow killing assay, we showed that the ΔexsEΔpscD had reduced virulence and thus confirmed that preferred food sources are less virulent than the wild type. Next we developed a high throughput feeding behaviour assay with 48 possible food colonies in order to screen a transposon mutant library and identify potential virulence genes. C. elegans identified and consumed preferred food colonies from a grid of 48 choices. The mutants identified as preferred food sources included known virulence genes, as well as novel genes not identified in previous C. elegans infection studies. Slow killing assays were performed and confirmed that several preferred food sources also showed reduced virulence. We propose that C. elegans feeding behaviour can be used as a sensitive indicator of virulence for P. aeruginosa PAO1.

  7. A multiplex reverse transcription-nested polymerase chain reaction for detection and differentiation of wild-type and vaccine strains of canine distemper virus

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    Cui Shang-jin

    2010-05-01

    Full Text Available Abstract A multiplex reverse transcription-nested polymerase chain reaction (RT-nPCR method was developed for the detection and differentiation of wild-type and vaccine strains of canine distemper virus (CDV. A pair of primers (P1 and P4 specific for CDV corresponding to the highly conserved region of the CDV genome were used as a common primer pair in the first-round PCR of the nested PCR. Primers P2 specific for CDV wild-type strains, were used as the forward primer together with the common reverse primer P4 in the second round of nested PCR. Primers P3, P5 specific for CDV wild-type strain or vaccine strain, were used as the forward primer together with the common reverse primer P4+P6 in the second round of nested PCR. A fragment of 177 bp was amplified from vaccine strain genomic RNA, and a fragment of 247 bp from wild-type strain genomic RNA in the RT-nPCR, and two fragments of 247 bp and 177 bp were amplified from the mixed samples of vaccine and wild-type strains. No amplification was achieved for uninfected cells, or cells infected with Newcastle disease virus (NDV, canine parvovirus (CPV, canine coronavirus (CCV, rabies virus (RV, or canine adenovirus (CAV. The RT-nPCR method was used to detect 30 field samples suspected of canine distemper from Heilongjiang and Jilin Provinces, and 51 samples in Shandong province. As a result of 30 samples, were found to be wild-type-like, and 5 to be vaccine-strain-like. The RT-nPCR method can be used to effectively detect and differentiate wild-type CDV-infected dogs from dogs vaccinated with CDV vaccine, and thus can be used in clinical detection and epidemiological surveillance.

  8. A multiplex reverse transcription-nested polymerase chain reaction for detection and differentiation of wild-type and vaccine strains of canine distemper virus

    Science.gov (United States)

    2010-01-01

    A multiplex reverse transcription-nested polymerase chain reaction (RT-nPCR) method was developed for the detection and differentiation of wild-type and vaccine strains of canine distemper virus (CDV). A pair of primers (P1 and P4) specific for CDV corresponding to the highly conserved region of the CDV genome were used as a common primer pair in the first-round PCR of the nested PCR. Primers P2 specific for CDV wild-type strains, were used as the forward primer together with the common reverse primer P4 in the second round of nested PCR. Primers P3, P5 specific for CDV wild-type strain or vaccine strain, were used as the forward primer together with the common reverse primer P4+P6 in the second round of nested PCR. A fragment of 177 bp was amplified from vaccine strain genomic RNA, and a fragment of 247 bp from wild-type strain genomic RNA in the RT-nPCR, and two fragments of 247 bp and 177 bp were amplified from the mixed samples of vaccine and wild-type strains. No amplification was achieved for uninfected cells, or cells infected with Newcastle disease virus (NDV), canine parvovirus (CPV), canine coronavirus (CCV), rabies virus (RV), or canine adenovirus (CAV). The RT-nPCR method was used to detect 30 field samples suspected of canine distemper from Heilongjiang and Jilin Provinces, and 51 samples in Shandong province. As a result of 30 samples, were found to be wild-type-like, and 5 to be vaccine-strain-like. The RT-nPCR method can be used to effectively detect and differentiate wild-type CDV-infected dogs from dogs vaccinated with CDV vaccine, and thus can be used in clinical detection and epidemiological surveillance. PMID:20433759

  9. Systematic strain construction and process development: Xylitol production by Saccharomyces cerevisiae expressing Candida tenuis xylose reductase in wild-type or mutant form.

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    Pratter, S M; Eixelsberger, T; Nidetzky, B

    2015-12-01

    A novel Saccharomyces cerevisiae whole-cell biocatalyst for xylitol production based on Candida tenuis xylose reductase (CtXR) is presented. Six recombinant strains expressing wild-type CtXR or an NADH-specific mutant were constructed and evaluated regarding effects of expression mode, promoter strength, biocatalyst concentration and medium composition. Intracellular XR activities ranged from 0.09 U mgProt(-1) to 1.05 U mgProt(-1) but did not correlate with the strains' xylitol productivities, indicating that other factors limited xylose conversion in the high-activity strains. The CtXR mutant decreased the biocatalyst's performance, suggesting use of the NADPH-preferring wild-type enzyme when (semi-)aerobic conditions are applied. In a bioreactor process, the best-performing strain converted 40 g L(-1) xylose with an initial productivity of 1.16 g L(-1)h(-1) and a xylitol yield of 100%. The obtained results underline the potential of CtXR wild-type for xylose reduction and point out parameters to improve "green" xylitol production. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Extracts of Cordia gilletii de wild (Boraginaceae) quench the quorum sensing of Pseudomonas aeruginosa PAO1.

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    Okusa, Philippe N; Rasamiravaka, Tsiry; Vandeputte, Olivier; Stévigny, Caroline; Jaziri, Mondher El; Duez, Pierre

    2014-01-01

    The fight against infectious diseases and antimicrobial resistances needs the exploration of new active compounds with new proprieties like disrupting quorum sensing (QS) mechanisms, which is a cell-to-cell communication that regulates bacterial virulence factors. In this work, leaves and root barks extracts of a Congolese medicinal plant, Cordia gilletii, were investigated for their effect on the production of Pseudomonas aeruginosa major virulence factors regulated by QS. The effect of C. gilletii extracts on virulence factors of P. aeruginosa PAO1 was studied by the evaluation of the production of pyocyanine, elastase and biofilm; and by the measurement of the expression of QS-related genes. The dichloromethane extract from root barks was found to quench the production of pyocyanin, a QS-dependent virulence factor in P. aeruginosa PAO1. Moreover, this extract specifically inhibits the expression of several QS-regulated genes (i.e. lasB, rhlA, lasI, lasR, rhlI, and rhlR) and reduces biofilm formation by PAO1. This study contributes to explain the efficacy of C. gilletii in the traditional treatment of infectious diseases caused by P. aeruginosa.

  11. Extracts of Cordia gilletii de wild (Boraginaceae) quench the quorum sensing of Pseudomonas aeruginosa PAO1

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    Okusa, Philippe N.; Rasamiravaka, Tsiry; Vandeputte, Olivier; Stévigny, Caroline; Jaziri, Mondher El; Duez, Pierre

    2014-01-01

    Aim: The fight against infectious diseases and antimicrobial resistances needs the exploration of new active compounds with new proprieties like disrupting quorum sensing (QS) mechanisms, which is a cell-to-cell communication that regulates bacterial virulence factors. In this work, leaves and root barks extracts of a Congolese medicinal plant, Cordia gilletii, were investigated for their effect on the production of Pseudomonas aeruginosa major virulence factors regulated by QS. Materials and Methods: The effect of C. gilletii extracts on virulence factors of P. aeruginosa PAO1 was studied by the evaluation of the production of pyocyanine, elastase and biofilm; and by the measurement of the expression of QS-related genes. Results: The dichloromethane extract from root barks was found to quench the production of pyocyanin, a QS-dependent virulence factor in P. aeruginosa PAO1. Moreover, this extract specifically inhibits the expression of several QS-regulated genes (i.e. lasB, rhlA, lasI, lasR, rhlI, and rhlR) and reduces biofilm formation by PAO1. Conclusion: This study contributes to explain the efficacy of C. gilletii in the traditional treatment of infectious diseases caused by P. aeruginosa. PMID:26401363

  12. Effects of ambroxol on biofilm adhesion and viability of Pseudomonas aeruginosa quorum sensing defective strain

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    Qi LU

    2013-07-01

    Full Text Available Objective To investigate the effects of ambroxol on the biofilm viability and pristine adhesion of Pseudomonas aeruginosa wild (PAO1 and quorum sensing defective strain (QS, gene deletion of ∆lasI and ∆rhlI. Methods The biofilm was treated by different concentrations (0, 1.875, 3.75mg/ml of ambroxol. The number of colony was measured with agar plate, multifunction fluorometer was used to measure the fluorescence intensity of PAO1 and QS strains at the bottom of 96-well plate. The adhesion ratio (% was calculated to determine the effects of ambroxol on bacterial biofilm adhesion. Results Ambroxol treatment reduced the survival rate of the mutant strains compared to that of wild strain, even though the QS strain had increased the adhesion in the presence of ambroxol compared to that of wild strain (P<0.05. Conclusion Ambroxol has a property of significantly antagonizing quorum-sensing system, suggesting that it might be of importance in treatment against chronic Pseudomonasaeruginosainfections.

  13. Cadmium tolerance, cysteine and thiol peptide levels in wild type and chromium-tolerant strains of Scenedesmus acutus (Chlorophyceae)

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    Torricelli, Elena; Gorbi, Gessica; Pawlik-Skowronska, Barbara; Di Toppi, Luigi Sanita; Corradi, Maria Grazia

    2004-07-14

    Two strains of the unicellular green alga Scenedesmus acutus with different sensitivity to hexavalent chromium were compared for their tolerance of cadmium, by means of growth and recovery tests, and determination of cysteine, reduced glutathione and phytochelatin content, after short-term exposure to various cadmium concentrations (from 1.125 to 27 {mu}M). Growth experiments showed that, after 7-day treatments with cadmium, the chromium-tolerant strain reached a significantly higher cell density and, after 24-h exposure to Cd, was able to resume growth significantly better than the wild type. Constitutive level of cysteine was higher in the chromium-tolerant strain, while glutathione levels were similar in the two strains. The higher content of cysteine and the maintenance of both reduced glutathione and phytochelatin high levels in the presence of cadmium, support the higher cadmium co-tolerance of the chromium-tolerant strain in comparison with the wild type one.

  14. Cadmium tolerance, cysteine and thiol peptide levels in wild type and chromium-tolerant strains of Scenedesmus acutus (Chlorophyceae)

    International Nuclear Information System (INIS)

    Torricelli, Elena; Gorbi, Gessica; Pawlik-Skowronska, Barbara; Di Toppi, Luigi Sanita; Corradi, Maria Grazia

    2004-01-01

    Two strains of the unicellular green alga Scenedesmus acutus with different sensitivity to hexavalent chromium were compared for their tolerance of cadmium, by means of growth and recovery tests, and determination of cysteine, reduced glutathione and phytochelatin content, after short-term exposure to various cadmium concentrations (from 1.125 to 27 μM). Growth experiments showed that, after 7-day treatments with cadmium, the chromium-tolerant strain reached a significantly higher cell density and, after 24-h exposure to Cd, was able to resume growth significantly better than the wild type. Constitutive level of cysteine was higher in the chromium-tolerant strain, while glutathione levels were similar in the two strains. The higher content of cysteine and the maintenance of both reduced glutathione and phytochelatin high levels in the presence of cadmium, support the higher cadmium co-tolerance of the chromium-tolerant strain in comparison with the wild type one

  15. Molecular characterization and phylogenetic relationship of wild type 1 poliovirus strains circulating across Pakistan and Afghanistan bordering areas during 2010-2012.

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    Shahzad Shaukat

    Full Text Available Pakistan and Afghanistan share a long uncontrolled border with extensive population movement on both sides. Wild poliovirus transmission has never been interrupted in this block due to war against terrorism, poor public health infrastructure, misconceptions about polio vaccines and inadequate immunization activities. All these issues complicate the eradication operations and reinforce the complexity of wiping out poliomyelitis from this region. This study illustrates the origins and routes of cross-border wild poliovirus type 1 (WPV1 transmission during 2010-2012 between Pakistan and Afghanistan. Sequence analyses were conducted based on complete VP1 capsid protein sequences for WPV1 study strains to determine the origin of poliovirus genetic lineages and their evolutionary relationships. Phylogenetic tree was constructed from VP1 gene sequences applying Maximum Likelihood method using Kimura 2- parameter model in MEGA program v 5.0. A total of 72 (14.3% out of 502 wild-type 1 polioviruses were found circulating in border areas of both countries during 2010-2012. Molecular phylogenetic analysis classified these strains in to two sub-genotypes with four clusters and 18 lineages. Genetic data confirmed that the most of WPV1 lineages (12; 66.6% were transmitted from Pakistan to Afghanistan. However, the genetic diversity was significantly reduced during 2012 as most of the lineages were completely eliminated. In conclusion, Pakistan-Afghanistan block has emerged as a single poliovirus reservoir sharing the multiple poliovirus lineages due to uncontrolled movement of people across the borders between two countries. If it is neglected, it can jeopardize the extensive global efforts done so-far to eradicate the poliovirus infection. Our data will be helpful to devise the preventive strategies for effective control of wild poliovirus transmission in this region.

  16. Spatial encoding in spinal sensorimotor circuits differs in different wild type mice strains

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    Schouenborg Jens

    2008-05-01

    Full Text Available Abstract Background Previous studies in the rat have shown that the spatial organisation of the receptive fields of nociceptive withdrawal reflex (NWR system are functionally adapted through experience dependent mechanisms, termed somatosensory imprinting, during postnatal development. Here we wanted to clarify 1 if mice exhibit a similar spatial encoding of sensory input to NWR as previously found in the rat and 2 if mice strains with a poor learning capacity in various behavioural tests, associated with deficient long term potention, also exhibit poor adaptation of NWR. The organisation of the NWR system in two adult wild type mouse strains with normal long term potentiation (LTP in hippocampus and two adult wild type mouse strains exhibiting deficiencies in corresponding LTP were used and compared to previous results in the rat. Receptive fields of reflexes in single hindlimb muscles were mapped with CO2 laser heat pulses. Results While the spatial organisation of the nociceptive receptive fields in mice with normal LTP were very similar to those in rats, the LTP impaired strains exhibited receptive fields of NWRs with aberrant sensitivity distributions. However, no difference was found in NWR thresholds or onset C-fibre latencies suggesting that the mechanisms determining general reflex sensitivity and somatosensory imprinting are different. Conclusion Our results thus confirm that sensory encoding in mice and rat NWR is similar, provided that mice strains with a good learning capability are studied and raise the possibility that LTP like mechanisms are involved in somatosensory imprinting.

  17. The development of 99mTc-d, 1-HM-PAO

    International Nuclear Information System (INIS)

    Bai Lanqin; Huang Jinjie; Fan Li; Bai Suzhen; Li Guoli; Jing Hui; Xiao Lun

    1991-12-01

    The 99m Tc-d,1-HM-PAO is an ideal radiopharmaceutical for regional cerebral blood perfusion imaging. The improvement of synthesis and separation of diastereoisomers leads to obtain high purity (>99%) of d, 1-HM-PAO and meso-HM-PAO. During separation H NMR spectroscopy was used to monitor the relative composition of these two diastereoisomers that can ensure the purity of pligand of d,1-HM-PAO. The intravenous injection of 99m Tc-d,1-HM-PAO was formed by adding fresh 99m Tc washing liquor into a sterile. Pyrogen-free and freeze-dried vial. The radiochemical purity (RCP) of 99m Tc-d,1-HM-PAO was greater than 80%. From the experiments of 99m Tc-d,1-HM-PAO in mice, after two minutes of intravenously (I>V>) administration about 2.24% of injected dose (I.D.)appeared in the brain, and after 24 hours about 72% of radioactivity of injected dose still left in the brain. But for the 99m Tc-meso-HM-PAO after two minutes of i.v. administration, about 1.93% of I.D. appeared in the brain, and 24 hours later, 25% of radioactivity of I.D. was in the brain. This result shows that in the brain the radioactivity of 99m Tc-meso-HM-PAO declines faster than that of 99m Td-d,1-HM-PAO

  18. Evaluation of MIC Strip Isavuconazole test for susceptibility testing of wild-type and non-wild-type Aspergillus fumigatus isolates

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    Arendrup, Maiken Cavling; Verweij, Paul; Nielsen, Henrik Vedel

    2017-01-01

    We evaluated the MIC Strip Isavuconazole test against EUCAST E.Def 9.3 by using 40 wild-type and 39 CYP51A mutant Aspergillus fumigatus strains. The strip full inhibition endpoint (FIE) and 80% growth inhibition endpoint were determined by two independent readers, reader 1 (R1) and R2. The essent......We evaluated the MIC Strip Isavuconazole test against EUCAST E.Def 9.3 by using 40 wild-type and 39 CYP51A mutant Aspergillus fumigatus strains. The strip full inhibition endpoint (FIE) and 80% growth inhibition endpoint were determined by two independent readers, reader 1 (R1) and R2...

  19. Mumps Hoshino and Torii vaccine strains were distinguished from circulating wild strains.

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    Sawada, Akihito; Yamaji, Yoshiaki; Nakayama, Tetsuo

    2013-06-01

    Aseptic meningitis and acute parotitis have been observed after mumps vaccination. Mumps outbreaks have been reported in Japan because of low vaccine coverage, and molecular differentiation is required to determine whether these cases are vaccine associated. RT-nested PCR was performed in the small hydrophobic gene region, and viruses were differentiated by restriction fragment length polymorphism assay. A total of 584 nucleotides were amplified. The PCR product of the Hoshino strain was cut into two fragments (313 and 271 nucleotides) by MfeI; that of the Torii strain was digested with EcoT22I, resulting in 332- and 252-nucleotide fragments. Both strains were genotype B and had an XbaI site, resulting in two fragments: 299 and 285 nucleotides. Current circulating wild types were cut only by XbaI or MfeI. However, the MfeI site of the wild types was different from that of the Hoshino strain, resulting in 451- and 133-nucleotide fragments. Using three restriction enzymes, two mumps vaccine strains were distinguished from wild types, and this separation was applied to the identification of vaccine-related adverse events.

  20. Regulation of Nicotine Tolerance by Quorum Sensing and High Efficiency of Quorum Quenching Under Nicotine Stress in Pseudomonas aeruginosa PAO1

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    Huiming Tang

    2018-03-01

    Full Text Available Quorum sensing (QS regulates the behavior of bacterial populations and promotes their adaptation and survival under stress. As QS is responsible for the virulence of vast majority of bacteria, quorum quenching (QQ, the interruption of QS, has become an attractive therapeutic strategy. However, the role of QS in stress tolerance and the efficiency of QQ under stress in bacteria are seldom explored. In this study, we demonstrated that QS-regulated catalase (CAT expression and biofilm formation help Pseudomonas aeruginosa PAO1 resist nicotine stress. CAT activity and biofilm formation in wild type (WT and ΔrhlR strains are significantly higher than those in the ΔlasR strain. Supplementation of ΔlasI strain with 3OC12-HSL showed similar CAT activity and biofilm formation as those of the WT strain. LasIR circuit rather than RhlIR circuit is vital to nicotine tolerance. Acylase I significantly decreased the production of virulence factors, namely elastase, pyocyanin, and pyoverdine under nicotine stress compared to the levels observed in the absence of nicotine stress. Thus, QQ is more efficient under stress. To our knowledge, this is the first study to report that QS contributes to nicotine tolerance in P. aeruginosa. This work facilitates a better application of QQ for the treatment of bacterial infections, especially under stress.

  1. Regulation of Nicotine Tolerance by Quorum Sensing and High Efficiency of Quorum Quenching Under Nicotine Stress in Pseudomonas aeruginosa PAO1.

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    Tang, Huiming; Zhang, Yunyun; Ma, Yifan; Tang, Mengmeng; Shen, Dongsheng; Wang, Meizhen

    2018-01-01

    Quorum sensing (QS) regulates the behavior of bacterial populations and promotes their adaptation and survival under stress. As QS is responsible for the virulence of vast majority of bacteria, quorum quenching (QQ), the interruption of QS, has become an attractive therapeutic strategy. However, the role of QS in stress tolerance and the efficiency of QQ under stress in bacteria are seldom explored. In this study, we demonstrated that QS-regulated catalase (CAT) expression and biofilm formation help Pseudomonas aeruginosa PAO1 resist nicotine stress. CAT activity and biofilm formation in wild type (WT) and Δ rhlR strains are significantly higher than those in the Δ lasR strain. Supplementation of Δ lasI strain with 3OC12-HSL showed similar CAT activity and biofilm formation as those of the WT strain. LasIR circuit rather than RhlIR circuit is vital to nicotine tolerance. Acylase I significantly decreased the production of virulence factors, namely elastase, pyocyanin, and pyoverdine under nicotine stress compared to the levels observed in the absence of nicotine stress. Thus, QQ is more efficient under stress. To our knowledge, this is the first study to report that QS contributes to nicotine tolerance in P. aeruginosa . This work facilitates a better application of QQ for the treatment of bacterial infections, especially under stress.

  2. Genetic recombination of tick-borne flaviviruses among wild-type strains.

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    Norberg, Peter; Roth, Anette; Bergström, Tomas

    2013-06-05

    Genetic recombination has been suggested to occur in mosquito-borne flaviviruses. In contrast, tick-borne flaviviruses have been thought to evolve in a clonal manner, although recent studies suggest that recombination occurs also for these viruses. We re-analyzed the data and found that previous conclusions on wild type recombination were probably falsely drawn due to misalignments of nucleotide sequences, ambiguities in GenBank sequences, or different laboratory culture histories suggestive of recombination events in laboratory. To evaluate if reliable predictions of wild type recombination of tick-borne flaviviruses can be made, we analyzed viral strains sequenced exclusively for this study, and other flavivirus sequences retrieved from GenBank. We detected genetic signals supporting recombination between viruses within the three clades of TBEV-Eu, TBEV-Sib and TBEV-Fe, respectively. Our results suggest that the tick-borne encephalitis viruses may undergo recombination under natural conditions, but that geographic barriers restrict most recombination events to involve only closely genetically related viruses. Copyright © 2013 Elsevier Inc. All rights reserved.

  3. Differential induction of Toll-like receptors & type 1 interferons by Sabin attenuated & wild type 1 polioviruses in human neuronal cells.

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    Mohanty, Madhu C; Deshpande, Jagadish M

    2013-01-01

    Polioviruses are the causative agent of paralytic poliomyelitis. Attenuated polioviruses (Sabin oral poliovirus vaccine strains) do not replicate efficiently in neurons as compared to the wild type polioviruses and therefore do not cause disease. This study was aimed to investigate the differential host immune response to wild type 1 poliovirus (wild PV) and Sabin attenuated type 1 poliovirus (Sabin PV) in cultured human neuronal cells. By using flow cytometry and real time PCR methods we examined host innate immune responses and compared the role of toll like receptors (TLRs) and cytoplasmic RNA helicases in cultured human neuronal cells (SK-N-SH) infected with Sabin PV and wild PV. Human neuronal cells expressed very low levels of TLRs constitutively. Sabin PV infection induced significantly higher expression of TLR3, TLR7 and melanoma differentiation-associated protein-5 (MDA-5) m-RNA in neuronal cells at the beginning of infection (up to 4 h) as compared to wild PV. Further, Sabin PV also induced the expression of interferon α/β at early time point of infection. The induced expression of IFN α/β gene by Sabin PV in neuronal cells could be suppressed by inhibiting TLR7. Neuronal cell innate immune response to Sabin and wild polioviruses differ significantly for TLR3, TLR7, MDA5 and type 1 interferons. Effects of TLR7 activation and interferon production and Sabin virus replication in neuronal cells need to be actively investigated in future studies.

  4. DNA vaccines encoding proteins from wild-type and attenuated canine distemper virus protect equally well against wild-type virus challenge.

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    Nielsen, Line; Jensen, Trine Hammer; Kristensen, Birte; Jensen, Tove Dannemann; Karlskov-Mortensen, Peter; Lund, Morten; Aasted, Bent; Blixenkrone-Møller, Merete

    2012-10-01

    Immunity induced by DNA vaccines containing the hemagglutinin (H) and nucleoprotein (N) genes of wild-type and attenuated canine distemper virus (CDV) was investigated in mink (Mustela vison), a highly susceptible natural host of CDV. All DNA-immunized mink seroconverted, and significant levels of virus-neutralizing (VN) antibodies were present on the day of challenge with wild-type CDV. The DNA vaccines also primed the cell-mediated memory responses, as indicated by an early increase in the number of interferon-gamma (IFN-γ)-producing lymphocytes after challenge. Importantly, the wild-type and attenuated CDV DNA vaccines had a long-term protective effect against wild-type CDV challenge. The vaccine-induced immunity induced by the H and N genes from wild-type CDV and those from attenuated CDV was comparable. Because these two DNA vaccines were shown to protect equally well against wild-type virus challenge, it is suggested that the genetic/antigenic heterogeneity between vaccine strains and contemporary wild-type strains are unlikely to cause vaccine failure.

  5. Differential induction of Toll-like receptors & type 1 interferons by Sabin attenuated & wild type 1 polioviruses in human neuronal cells

    Directory of Open Access Journals (Sweden)

    Madhu C Mohanty

    2013-01-01

    Full Text Available Background & objectives: Polioviruses are the causative agent of paralytic poliomyelitis. Attenuated polioviruses (Sabin oral poliovirus vaccine strains do not replicate efficiently in neurons as compared to the wild type polioviruses and therefore do not cause disease. This study was aimed to investigate the differential host immune response to wild type 1 poliovirus (wild PV and Sabin attenuated type 1 poliovirus (Sabin PV in cultured human neuronal cells. Methods: By using flow cytometry and real time PCR methods we examined host innate immune responses and compared the role of toll like receptors (TLRs and cytoplasmic RNA helicases in cultured human neuronal cells (SK-N-SH infected with Sabin PV and wild PV. Results: Human neuronal cells expressed very low levels of TLRs constitutively. Sabin PV infection induced significantly higher expression of TLR3, TLR7 and melanoma differentiation-associated protein-5 (MDA-5 m-RNA in neuronal cells at the beginning of infection (up to 4 h as compared to wild PV. Further, Sabin PV also induced the expression of interferon α/β at early time point of infection. The induced expression of IFN α/β gene by Sabin PV in neuronal cells could be suppressed by inhibiting TLR7. Interpretation & conclusions: Neuronal cell innate immune response to Sabin and wild polioviruses differ significantly for TLR3, TLR7, MDA5 and type 1 interferons. Effects of TLR7 activation and interferon production and Sabin virus replication in neuronal cells need to be actively investigated in future studies.

  6. Establishment of new transmissible and drug-sensitive human immunodeficiency virus type 1 wild types due to transmission of nucleoside analogue-resistant virus.

    Science.gov (United States)

    de Ronde, A; van Dooren, M; van Der Hoek, L; Bouwhuis, D; de Rooij, E; van Gemen, B; de Boer, R; Goudsmit, J

    2001-01-01

    Sequence analysis of human immunodeficiency virus type 1 (HIV-1) from 74 persons with acute infections identified eight strains with mutations in the reverse transcriptase (RT) gene at positions 41, 67, 68, 70, 215, and 219 associated with resistance to the nucleoside analogue zidovudine (AZT). Follow-up of the fate of these resistant HIV-1 strains in four newly infected individuals revealed that they were readily replaced by sensitive strains. The RT of the resistant viruses changed at amino acid 215 from tyrosine (Y) to aspartic acid (D) or serine (S), with asparagine (N) as a transient intermediate, indicating the establishment of new wild types. When we introduced these mutations and the original threonine (T)-containing wild type into infectious molecular clones and assessed their competitive advantage in vitro, the order of fitness was in accord with the in vivo observations: 215Y types with D, S, or N residues at position 215 may be warranted in order to estimate the threat to long-term efficacy of regimens including nucleoside analogues.

  7. Comparison of the proteomes of three yeast wild type strains: CEN.PK2, FY1679 and W303

    DEFF Research Database (Denmark)

    Rogowska-Wrzesinska, A.; Mose Larsen, P.; Blomberg, A.

    2001-01-01

    Yeast deletion strains created during gene function analysis projects very often show drastic phenotypic differences depending on the genetic background used. These results indicate the existence of important molecular differences between the CEN.PK2, FY1679 and W303 wild type strains...

  8. lambda. -prophage induction in repair-deficient and wild type E. coli strains by. gamma. -rays and heavy ions

    Energy Technology Data Exchange (ETDEWEB)

    Bonev, M.N.; Kozubek, S.; Krasavin, E.A.; Amirtajev, K.G. (Joint Inst. for Nuclear Research, Dubna (USSR))

    1990-05-01

    {lambda}-prophage induction in repair-deficient and wild-type E. coli strains by heavy ions and {gamma}-rays was investigated. The dose dependence of the fraction of induced cells has been measured and its initial slope ({lambda}-induction potency) determined. Induction by {gamma}-rays was found to be more efficient in a polA-repair-deficient strain; the value of {lambda}-induction potency is zero in lexA{sup -} and recA{sup -} strains. The {lambda}-induction potency potency increased with LET for wild-type cells but remained constant in polA{sup -} mutant cells. It is suggested that DNA damage triggering the {lambda}-prophage induction in the case of ionizing radiation could be a type of DNA single-strand break with complex structures which cannot be repaired by fast repair processes, and requires a substantial level of energy deposition for induction in a DNA molecule. (author).

  9. Anthelmintic effect of Psidium guajava and Tagetes erecta on wild-type and Levamisole-resistant Caenorhabditis elegans strains.

    Science.gov (United States)

    Piña-Vázquez, Denia M; Mayoral-Peña, Zyanya; Gómez-Sánchez, Maricela; Salazar-Olivo, Luis A; Arellano-Carbajal, Fausto

    2017-04-18

    Psidium guajava and Tagetes erecta have been used traditionally to treat gastrointestinal parasites, but their active metabolites and mechanisms of action remain largely unknown. To evaluate the anthelmintic potential of Psidium guajava and Tagetes erecta extracts on Levamisole-sensitive and Levamisole-resistant strains of the model nematode Caenorhabditis elegans. Aqueous extracts of Psidium guajava (PGE) and Tagetes erecta (TEE) were assayed on locomotion and egg-laying behaviors of the wild-type (N2) and Levamisole-resistant (CB193) strains of Caenorhabditis elegans. Both extracts paralyzed wild-type and Levamisole-resistant nematodes in a dose-dependent manner. In wild-type worms, TEE 25mg/mL induced a 75% paralysis after 8h of treatment and PGE 25mg/mL induced a 100% paralysis after 4h of treatment. PGE exerted a similar paralyzing effect on N2 wild-type and CB193 Levamisole-resistant worms, while TEE only partially paralyzed CB193 worms. TEE 25mg/mL decreased N2 egg-laying by 65% with respect to the untreated control, while PGE did it by 40%. Psidium guajava leaves and Tagetes erecta flower-heads possess hydrosoluble compounds that block the motility of Caenorhabditis elegans by a mechanism different to that of the anthelmintic drug Levamisole. Effects are also observable on oviposition, which was diminished in the wild-type worms. The strong anthelmintic effects in crude extracts of these plants warrants future work to identify their active compounds and to elucidate their molecular mechanisms of action. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

  10. UV-sensitivity and repair of UV-damage in Salmonella of wild type

    International Nuclear Information System (INIS)

    Kondratiev, Y.S.; Brukhansky, G.V.; Andreeva, I.V.; Skavronskaya, A.G.

    1977-01-01

    The UV-sensitivity of wild type Salmonella strains has been compared to that of wild type E.coli and its UV-sensitive mutants. Many wild type Salmonella strains are 4-5 times more sensitive than wild type E.coli and their inactivation curve is similar to that for E.coli with a mutation in the polA gene. Alkaline sucrose gradient centrifugation has shown a deficiency of these strains in normal excision repair of UV-damaged DNA. This deficiency is not a Salmonella genus feature because one strain as resistant as wild type E.coli was found. This resistant strain showed normal excision repair in alkaline sucrose gradient centrifugation experiments. The possible influence of plasmids and mutations in repair genes on the ability of Salmonella to repair UV-damaged DNA is discussed. (orig.) [de

  11. UV-sensitivity and repair of UV-damage in Salmonella of wild type

    Energy Technology Data Exchange (ETDEWEB)

    Kondratiev, Y S; Brukhansky, G V; Andreeva, I V; Skavronskaya, A G [Akademiya Meditsinskikh Nauk SSSR, Moscow. Inst. Ehpidemiologii i Mikrobiologii

    1977-12-01

    The UV-sensitivity of wild type Salmonella strains has been compared to that of wild type E.coli and its UV-sensitive mutants. Many wild type Salmonella strains are 4-5 times more sensitive than wild type E.coli and their inactivation curve is similar to that for E.coli with a mutation in the polA gene. Alkaline sucrose gradient centrifugation has shown a deficiency of these strains in normal excision repair of UV-damaged DNA. This deficiency is not a Salmonella genus feature because one strain as resistant as wild type E.coli was found. This resistant strain showed normal excision repair in alkaline sucrose gradient centrifugation experiments. The possible influence of plasmids and mutations in repair genes on the ability of Salmonella to repair UV-damaged DNA is discussed.

  12. Identification of enzymes and quantification of metabolic fluxes in the wild type and in a recombinant Aspergillus oryzae strain

    DEFF Research Database (Denmark)

    Pedersen, Henrik; Carlsen, Morten; Nielsen, Jens Bredal

    1999-01-01

    Two alpha-amylase-producing strains of Aspergillus oryzae, a wild-type strain and a recombinant containing additional copies of the alpha-amylase gene, were characterized,vith respect to enzyme activities, localization of enzymes to the mitochondria or cytosol, macromolecular composition...

  13. Unique Safety Issues Associated with Virus Vectored Vaccines: Potential for and Theoretical Consequences of Recombination with Wild Type Virus Strains

    Science.gov (United States)

    Condit, Richard C.; Williamson, Anna-Lise; Sheets, Rebecca; Seligman, Stephen J.; Monath, Thomas P.; Excler, Jean-Louis; Gurwith, Marc; Bok, Karin; Robertson, James S.; Kim, Denny; Hendry, Michael; Singh, Vidisha; Mac, Lisa M.; Chen, Robert T.

    2016-01-01

    In 2003 and 2013, the World Health Organization convened informal consultations on characterization and quality aspects of vaccines based on live virus vectors. In the resulting reports, one of several issues raised for future study was the potential for recombination of virus-vectored vaccines with wild type pathogenic virus strains. This paper presents an assessment of this issue formulated by the Brighton Collaboration. To provide an appropriate context for understanding the potential for recombination of virus-vectored vaccines, we review briefly the current status of virus vectored vaccines, mechanisms of recombination between viruses, experience with recombination involving live attenuated vaccines in the field, and concerns raised previously in the literature regarding recombination of virus-vectored vaccines with wild type virus strains. We then present a discussion of the major variables that could influence recombination between a virus-vectored vaccine and circulating wild type virus and the consequences of such recombination, including intrinsic recombination properties of the parent virus used as a vector; sequence relatedness of vector and wild virus; virus host range, pathogenesis and transmission; replication competency of vector in target host; mechanism of vector attenuation; additional factors potentially affecting virulence; and circulation of multiple recombinant vectors in the same target population. Finally, we present some guiding principles for vector design and testing intended to anticipate and mitigate the potential for and consequences of recombination of virus-vectored vaccines with wild type pathogenic virus strains. PMID:27346303

  14. PBI creams: a spontaneously mutated mouse strain showing wild animal-type reactivity.

    Science.gov (United States)

    Hendrie, C A; Van Driel, K S; Talling, J C; Inglis, I R

    2001-01-01

    PBI creams are mice derived from warfarin-resistant wild stock that has been maintained under laboratory conditions since the 1970s. This study compares their behaviour to that of laboratory mice and wild house and wood mice. Animals were tested in a black/white box and a 2.64x1.4 m runway. In the black/white box, the behaviour of PBI creams was not significantly different from that of house mice and differed most from that of laboratory mice. Notably, the PBI creams showed the greatest activity and escape-orientated behaviours. When animals were approached by the experimenter in the open runway test, the PBI creams had higher flight speeds than both house and wood mice, whilst laboratory mice failed to respond. In the closed runway test where the animals could not escape, the PBI creams, house mice and wood mice all turned and attempted to run past the approaching experimenter, whilst the laboratory mice again failed to react. At the end of this test session, the time taken to catch each animal was recorded. It took less than 5 s to catch laboratory mice but significantly longer to catch the wild strains and the PBI creams (90-100 s for the latter). In these tests, the PBI creams showed wild animal-type reactivity, and as this behaviour has been retained in the laboratory colony for over 30 years, these animals may be useful in the study of the physiological and genetic basis of fear/anxiety in mice.

  15. Wild type measles virus attenuation independent of type I IFN

    Directory of Open Access Journals (Sweden)

    Horvat Branka

    2008-02-01

    Full Text Available Abstract Background Measles virus attenuation has been historically performed by adaptation to cell culture. The current dogma is that attenuated virus strains induce more type I IFN and are more resistant to IFN-induced protection than wild type (wt. Results The adaptation of a measles virus isolate (G954-PBL by 13 passages in Vero cells induced a strong attenuation of this strain in vivo. The adapted virus (G954-V13 differs from its parental strain by only 5 amino acids (4 in P/V/C and 1 in the M gene. While a vaccine strain, Edmonston Zagreb, could replicate equally well in various primate cells, both G954 strains exhibited restriction to the specific cell type used initially for their propagation. Surprisingly, we observed that both G954 strains induced type I IFN, the wt strain inducing even more than the attenuated ones, particularly in human plasmacytoid Dendritic Cells. Type I IFN-induced protection from the infection of both G954 strains depended on the cell type analyzed, being less efficient in the cells used to grow the viral strain. Conclusion Thus, mutations in M and P/V/C proteins can critically affect MV pathogenicity, cellular tropism and lead to virus attenuation without interfering with the α/β IFN system.

  16. Genetic relationships and epidemiological links between wild type 1 poliovirus isolates in Pakistan and Afghanistan.

    Science.gov (United States)

    Angez, Mehar; Shaukat, Shahzad; Alam, Muhammad M; Sharif, Salmaan; Khurshid, Adnan; Zaidi, Syed Sohail Zahoor

    2012-02-22

    Efforts have been made to eliminate wild poliovirus transmission since 1988 when the World Health Organization began its global eradication campaign. Since then, the incidence of polio has decreased significantly. However, serotype 1 and serotype 3 still circulate endemically in Pakistan and Afghanistan. Both countries constitute a single epidemiologic block representing one of the three remaining major global reservoirs of poliovirus transmission. In this study we used genetic sequence data to investigate transmission links among viruses from diverse locations during 2005-2007. In order to find the origins and routes of wild type 1 poliovirus circulation, polioviruses were isolated from faecal samples of Acute Flaccid Paralysis (AFP) patients. We used viral cultures, two intratypic differentiation methods PCR, ELISA to characterize as vaccine or wild type 1 and nucleic acid sequencing of entire VP1 region of poliovirus genome to determine the genetic relatedness. One hundred eleven wild type 1 poliovirus isolates were subjected to nucleotide sequencing for genetic variation study. Considering the 15% divergence of the sequences from Sabin 1, Phylogenetic analysis by MEGA software revealed that active inter and intra country transmission of many genetically distinct strains of wild poliovirus type 1 belonged to genotype SOAS which is indigenous in this region. By grouping wild type 1 polioviruses according to nucleotide sequence homology, three distinct clusters A, B and C were obtained with multiple chains of transmission together with some silent circulations represented by orphan lineages. Our results emphasize that there was a persistent transmission of wild type 1 polioviruses in Pakistan and Afghanistan during 2005-2007. The epidemiologic information provided by the sequence data can contribute to the formulation of better strategies for poliomyelitis control to those critical areas, associated with high risk population groups which include migrants

  17. Genetic relationships and epidemiological links between wild type 1 poliovirus isolates in Pakistan and Afghanistan

    Directory of Open Access Journals (Sweden)

    Angez Mehar

    2012-02-01

    Full Text Available Abstract Background/Aim Efforts have been made to eliminate wild poliovirus transmission since 1988 when the World Health Organization began its global eradication campaign. Since then, the incidence of polio has decreased significantly. However, serotype 1 and serotype 3 still circulate endemically in Pakistan and Afghanistan. Both countries constitute a single epidemiologic block representing one of the three remaining major global reservoirs of poliovirus transmission. In this study we used genetic sequence data to investigate transmission links among viruses from diverse locations during 2005-2007. Methods In order to find the origins and routes of wild type 1 poliovirus circulation, polioviruses were isolated from faecal samples of Acute Flaccid Paralysis (AFP patients. We used viral cultures, two intratypic differentiation methods PCR, ELISA to characterize as vaccine or wild type 1 and nucleic acid sequencing of entire VP1 region of poliovirus genome to determine the genetic relatedness. Results One hundred eleven wild type 1 poliovirus isolates were subjected to nucleotide sequencing for genetic variation study. Considering the 15% divergence of the sequences from Sabin 1, Phylogenetic analysis by MEGA software revealed that active inter and intra country transmission of many genetically distinct strains of wild poliovirus type 1 belonged to genotype SOAS which is indigenous in this region. By grouping wild type 1 polioviruses according to nucleotide sequence homology, three distinct clusters A, B and C were obtained with multiple chains of transmission together with some silent circulations represented by orphan lineages. Conclusion Our results emphasize that there was a persistent transmission of wild type1 polioviruses in Pakistan and Afghanistan during 2005-2007. The epidemiologic information provided by the sequence data can contribute to the formulation of better strategies for poliomyelitis control to those critical areas

  18. Fructose 6-phosphate phosphoketolase activity in wild-type strains of Lactobacillus, isolated from the intestinal tract of pigs.

    Science.gov (United States)

    Bolado-Martínez, E; Acedo-Félix, E; Peregrino-Uriarte, A B; Yepiz-Plascencia, G

    2012-01-01

    Phosphoketolases are key enzymes of the phosphoketolase pathway of heterofermentative lactic acid bacteria, which include lactobacilli. In heterofermentative lactobacilli xylulose 5-phosphate phosphoketolase (X5PPK) is the main enzyme of the phosphoketolase pathway. However, activity of fructose 6-phosphate phosphoketolase (F6PPK) has always been considered absent in lactic acid bacteria. In this study, the F6PPK activity was detected in 24 porcine wild-type strains of Lactobacillus reuteri and Lactobacillus mucosae, but not in the Lactobacillus salivarius or in L. reuteri ATCC strains. The activity of F6PPK increased after treatment of the culture at low-pH and diminished after porcine bile-salts stress conditions in wild-type strains of L. reuteri. Colorimetric quantification at 505 nm allowed to differentiate between microbial strains with low activity and without the activity of F6PPK. Additionally, activity of F6PPK and the X5PPK gene expression levels were evaluated by real time PCR, under stress and nonstress conditions, in 3 L. reuteri strains. Although an exact correlation, between enzyme activity and gene expression was not obtained, it remains possible that the xpk gene codes for a phosphoketolase with dual substrate, at least in the analyzed strains of L. reuteri.

  19. Extracellular enzyme activities during lignocellulose degradation by Streptomyces spp.: a comparative study of wild-type and genetically manipulated strains

    International Nuclear Information System (INIS)

    Ramachandra, M.; Crawford, D.L.; Pometto, A.L. III

    1987-01-01

    The wild-type ligninolytic actinomycete Streptomyces viridosporus T7A and two genetically manipulated strains with enhanced abilities to produce a water-soluble lignin degradation intermediate, an acid-precipitable polymeric lignin (APPL), were grown on lignocellulose in solid-state fermentation cultures. Culture filtrates were periodically collected, analyzed for APPL, and assayed for extracellular lignocellulose-catabolizing enzyme activities. Two APPL-overproducing strains, UV irradiation mutant T7A-81 and protoplast fusion recombinant SR-10, had higher and longer persisting peroxidase, esterase, and endoglucanase activities than did the wild-type strain T7A. Results implicated one or more of these enzymes in lignin solubilization. Only mutant T7A-81 had higher xylanase activity than the wild type. The peroxidase was induced by both lignocellulose and APPL. This extracellular enzyme has some similarities to previously described ligninases in fungi. This is the first report of such an enzyme in Streptomyces spp. Four peroxidase isozymes were present, and all catalyzed the oxidation of 3,4-dihydroxyphenylalanine, while one also catalyzed hydrogen peroxide-dependent oxidation of homoprotocatechuic acid and caffeic acid. Three constitutive esterase isozymes were produced which differed in substrate specificity toward α-naphthyl acetate and α-naphthyl butyrate. Three endoglucanase bands, which also exhibited a low level of xylanase activity, were identified on polyacrylamide gels as was one xylanase-specific band. There were no major differences in the isoenzymes produced by the different strains. The probable role of each enzyme in lignocellulose degradation is discussed

  20. Identification of concomitant infection with Chlamydia trachomatis IncA-negative mutant and wild-type strains by genomic, transcriptional, and biological characterizations.

    Science.gov (United States)

    Suchland, Robert J; Jeffrey, Brendan M; Xia, Minsheng; Bhatia, Ajay; Chu, Hencelyn G; Rockey, Daniel D; Stamm, Walter E

    2008-12-01

    Clinical isolates of Chlamydia trachomatis that lack IncA on their inclusion membrane form nonfusogenic inclusions and have been associated with milder, subclinical infections in patients. The molecular events associated with the generation of IncA-negative strains and their roles in chlamydial sexually transmitted infections are not clear. We explored the biology of the IncA-negative strains by analyzing their genomic structure, transcription, and growth characteristics in vitro and in vivo in comparison with IncA-positive C. trachomatis strains. Three clinical samples were identified that contained a mixture of IncA-positive and -negative same-serovar C. trachomatis populations, and two more such pairs were found in serial isolates from persistently infected individuals. Genomic sequence analysis of individual strains from each of two serovar-matched pairs showed that these pairs were very similar genetically. In contrast, the genome sequence of an unmatched IncA-negative strain contained over 5,000 nucleotide polymorphisms relative to the genome sequence of a serovar-matched but otherwise unlinked strain. Transcriptional analysis, in vitro culture kinetics, and animal modeling demonstrated that IncA-negative strains isolated in the presence of a serovar-matched wild-type strain are phenotypically more similar to the wild-type strain than are IncA-negative strains isolated in the absence of a serovar-matched wild-type strain. These studies support a model suggesting that a change from an IncA-positive strain to the previously described IncA-negative phenotype may involve multiple steps, the first of which involves a translational inactivation of incA, associated with subsequent unidentified steps that lead to the observed decrease in transcript level, differences in growth rate, and differences in mouse infectivity.

  1. Molecular Modeling and Structural Stability of Wild-Type and Mutant CYP51 from Leishmania major: In Vitro and In Silico Analysis of a Laboratory Strain

    Directory of Open Access Journals (Sweden)

    Masoud Keighobadi

    2018-03-01

    Full Text Available Cutaneous leishmaniasis is a neglected tropical disease and a major public health in the most countries. Leishmania major is the most common cause of cutaneous leishmaniasis. In the Leishmania parasites, sterol 14α-demethylase (CYP51, which is involved in the biosynthesis of sterols, has been identified as an attractive target for development of new therapeutic agents. In this study, the sequence and structure of CYP51 in a laboratory strain (MRHO/IR/75/ER of L. major were determined and compared to the wild-type strain. The results showed 19 mutations including seven non-synonymous and 12 synonymous ones in the CYP51 sequence of strain MRHO/IR/75/ER. Importantly, an arginine to lysine substitution at position of 474 resulted in destabilization of CYP51 (ΔΔG = 1.17 kcal/mol in the laboratory strain; however, when the overall effects of all substitutions were evaluated by 100 ns molecular dynamics simulation, the final structure did not show any significant changes (p-value < 0.05 in stability parameter of the strain MRHO/IR/75/ER compared to the wild-type protein. The energy level for the CYP51 of wild-type and MRHO/IR/75/ER strain were −40,027.1 and −39,706.48 Kcal/mol respectively. The overall Root-mean-square deviation (RMSD deviation between two proteins was less than 1 Å throughout the simulation and Root-mean-square fluctuation (RMSF plot also showed no substantial differences between amino acids fluctuation of the both protein. The results also showed that, these mutations were located on the protein periphery that neither interferes with protein folding nor with substrate/inhibitor binding. Therefore, L. major strain MRHO/IR/75/ER is suggested as a suitable laboratory model for studying biological role of CYP51 and inhibitory effects of sterol 14α-demethylase inhibitors.

  2. Newcastle disease B1 vaccine strain in wild rock pigeons in Atlanta, Georgia

    Science.gov (United States)

    From June to October of 2012, samples were collected from wild Rock Pigeons (Columba livia) in urban neighborhoods of Atlanta, Georgia to ascertain the prevalence of pigeon paramyxovirus serotype-1 (PPMV-1). PPMV-1 strains are a subset of avian paramyxovirus serotype-1 (APMV-1) commonly isolated fro...

  3. One-step multiplex real-time RT-PCR assay for detecting and genotyping wild-type group A rotavirus strains and vaccine strains (Rotarix® and RotaTeq®) in stool samples

    Science.gov (United States)

    Mijatovic-Rustempasic, Slavica; Esona, Mathew D.; Tam, Ka Ian; Quaye, Osbourne; Bowen, Michael D.

    2016-01-01

    Background. Group A rotavirus (RVA) infection is the major cause of acute gastroenteritis (AGE) in young children worldwide. Introduction of two live-attenuated rotavirus vaccines, RotaTeq® and Rotarix®, has dramatically reduced RVA associated AGE and mortality in developed as well as in many developing countries. High-throughput methods are needed to genotype rotavirus wild-type strains and to identify vaccine strains in stool samples. Quantitative RT-PCR assays (qRT-PCR) offer several advantages including increased sensitivity, higher throughput, and faster turnaround time. Methods. In this study, a one-step multiplex qRT-PCR assay was developed to detect and genotype wild-type strains and vaccine (Rotarix® and RotaTeq®) rotavirus strains along with an internal processing control (Xeno or MS2 RNA). Real-time RT-PCR assays were designed for VP7 (G1, G2, G3, G4, G9, G12) and VP4 (P[4], P[6] and P[8]) genotypes. The multiplex qRT-PCR assay also included previously published NSP3 qRT-PCR for rotavirus detection and Rotarix® NSP2 and RotaTeq® VP6 qRT-PCRs for detection of Rotarix® and RotaTeq® vaccine strains respectively. The multiplex qRT-PCR assay was validated using 853 sequence confirmed stool samples and 24 lab cultured strains of different rotavirus genotypes. By using thermostable rTth polymerase enzyme, dsRNA denaturation, reverse transcription (RT) and amplification (PCR) steps were performed in single tube by uninterrupted thermocycling profile to reduce chances of sample cross contamination and for rapid generation of results. For quantification, standard curves were generated using dsRNA transcripts derived from RVA gene segments. Results. The VP7 qRT-PCRs exhibited 98.8–100% sensitivity, 99.7–100% specificity, 85–95% efficiency and a limit of detection of 4–60 copies per singleplex reaction. The VP7 qRT-PCRs exhibited 81–92% efficiency and limit of detection of 150–600 copies in multiplex reactions. The VP4 qRT-PCRs exhibited 98.8

  4. Differentiation between probiotic and wild-type Bacillus cereus isolates by antibiotic susceptibility test and Fourier transform infrared spectroscopy (FT-IR).

    Science.gov (United States)

    Mietke, Henriette; Beer, W; Schleif, Julia; Schabert, G; Reissbrodt, R

    2010-05-30

    Animal feed often contains probiotic Bacillus strains used as feed additives. Spores of the non-pathogenic B. cereus var. toyoi (product name Toyocerin) are used. Distinguishing between toxic wild-type Bacillus cereus strains and this probiotic strain is essential for evaluating the quality and risk of feed. Bacillus cereus CIP 5832 (product name Paciflor was used as probiotic strain until 2001. The properties of the two probiotic strains are quite similar. Differentiating between probiotic strains and wild-type B. cereus strains is not easy. ss-lactam antibiotics such as penicillin and cefamandole exhibit an inhibition zone in the agar diffusion test of probiotic B. cereus strains which are not seen for wild-type strains. Therefore, performing the agar diffusion test first may make sense before FT-IR testing. When randomly checking these strains by Fourier transform infrared spectroscopy (FT-IR), the probiotic B. cereus strains were separated from wild-type B. cereus/B. thuringiensis/B. mycoides/B. weihenstephanensis strains by means of hierarchical cluster analysis. The discriminatory information was contained in the spectral windows 3000-2800 cm(-1) ("fatty acid region"), 1200-900 cm(-1) ("carbohydrate region") and 900-700 cm(-1) ("fingerprint region"). It is concluded that FT-IR spectroscopy can be used for the rapid quality control and risk analysis of animal feed containing probiotic B. cereus strains. (c) 2010 Elsevier B.V. All rights reserved.

  5. Strains of avian paramyxovirus type 1 of low pathogenicity for chickens isolated from poultry and wild birds in Denmark

    DEFF Research Database (Denmark)

    Jørgensen, Poul Henrik; Handberg, Kurt; Ahrens, Peter

    2004-01-01

    Twenty-one strains of avian paramyxovirus type 1 of low virulence for chickens were isolated in Denmark between 1996 and the beginning of 2003. The low virulence of the strains was demonstrated by sequencing the fusion (F) gene at the cleavage site motif and in some cases by determining the intra......Twenty-one strains of avian paramyxovirus type 1 of low virulence for chickens were isolated in Denmark between 1996 and the beginning of 2003. The low virulence of the strains was demonstrated by sequencing the fusion (F) gene at the cleavage site motif and in some cases by determining...

  6. Comparison of mating performance of medfly (Diptera: Tephritidae) genetic sexing and wild type strains: field cage and video recording experiments

    International Nuclear Information System (INIS)

    Calcagno, G.E.; Vilardi, J.C.; Manso, F.

    2002-01-01

    To improve the efficiency of the sterile insect technique (SIT) efforts are being devoted to obtain genetic sexing strains (GSS). The present work was carried out in order to compare the mating efficiency of flies from the GSS [(Ty34228 y + /X)sw x ] and from a wild type strain (Mendoza). Females of the GSS (T228) exhibit longer embryonic development, while males develop in a normal time period. In a field-cage experiment, mating competitiveness was compared between the T228 and the Mendoza, Argentina mass reared strain. The number and duration of matings and the location of copula in the tree were recorded. The analysis was repeated using irradiated males of T228. The results showed that mating efficiency of the GSS is good in comparison with that of the Mendoza strain. Although copulatory success in T228 is reduced by the radiation treatment, the high numbers of sterilized males released would compensate this effect in the control programs. In a second experiment, under laboratory conditions, video recording techniques were applied. In this case two virgin males, one of the GSS and one emerged from wild collected fruits, competed during 30 min for a virgin wild female. The proportion of successful males did not differ between strains, but some differences were observed between strains in the time spent in different stages of the courtship. Males of the T228 were more aggressive, and they attempted to copulate with the other male more frequently than did wild males. These differences may be due to selection for more aggressive individuals under the overcrowded laboratory breeding conditions for this strain. (author)

  7. Real-time reverse transcription polymerase chain reaction method for detection of Canine distemper virus modified live vaccine shedding for differentiation from infection with wild-type strains.

    Science.gov (United States)

    Wilkes, Rebecca P; Sanchez, Elena; Riley, Matthew C; Kennedy, Melissa A

    2014-01-01

    Canine distemper virus (CDV) remains a common cause of infectious disease in dogs, particularly in high-density housing situations such as shelters. Vaccination of all dogs against CDV is recommended at the time of admission to animal shelters and many use a modified live virus (MLV) vaccine. From a diagnostic standpoint for dogs with suspected CDV infection, this is problematic because highly sensitive diagnostic real-time reverse transcription polymerase chain reaction (RT-PCR) tests are able to detect MLV virus in clinical samples. Real-time PCR can be used to quantitate amount of virus shedding and can differentiate vaccine strains from wild-type strains when shedding is high. However, differentiation by quantitation is not possible in vaccinated animals during acute infection, when shedding is low and could be mistaken for low level vaccine virus shedding. While there are gel-based RT-PCR assays for differentiation of vaccine strains from field strains based on sequence differences, the sensitivity of these assays is unable to match that of the real-time RT-PCR assay currently used in the authors' laboratory. Therefore, a real-time RT-PCR assay was developed that detects CDV MLV vaccine strains and distinguishes them from wild-type strains based on nucleotide sequence differences, rather than the amount of viral RNA in the sample. The test is highly sensitive, with detection of as few as 5 virus genomic copies (corresponding to 10(-1) TCID(50)). Sequencing of the DNA real-time products also allows phylogenetic differentiation of the wild-type strains. This test will aid diagnosis during outbreaks of CDV in recently vaccinated animals.

  8. Development of 99mTc-labelled the d,1-diasteroisomer of HM-PAO for cerebral blood flow imaging

    International Nuclear Information System (INIS)

    Lun Xiao.

    1989-10-01

    The d,1-diastereoisomer of hexamethyl propyleneamine oxime (HM-PAO) was selected as the preferred ligand for Tc-99m as a radiotracer for cerebral perfusion imaging. Further improvement of the synthesis and isolation method of HM-PAO resulted in pure d,1-HM-PAO and pure meso-HM-PAO. The neutral, lipophilic Tc-99m complexes of d,1-HM-PAO and meso-HM-PAO were formed in high yield by stannous reduction of Mo-99/Tc-99m generator eluate, respectively. Two minutes following i.v. administration of Tc-99m-d,1-HM-PAO in mice, 2.24% of the injected dose appears in the brain. Little washout of the tracer is observed up to 24-hour post injection. Two minutes following i.v. administration of Tc-99m-meso-HM-PAO in mice, 1.9% of the injected dose appears in the brain. The radioactivity of Tc-99m-meso-HM-PAO declined faster than that of Tc-99m-d,1-HM-PAO did in the brain up to 24-hour post injection. 12 refs, 5 figs, 5 tabs

  9. Kinetic modeling of batch fermentation for Populus hydrolysate tolerant mutant and wild type strains of Clostridium thermocellum.

    Science.gov (United States)

    Linville, Jessica L; Rodriguez, Miguel; Mielenz, Jonathan R; Cox, Chris D

    2013-11-01

    The extent of inhibition of two strains of Clostridium thermocellum by a Populus hydrolysate was investigated. A Monod-based model of wild type (WT) and Populus hydrolysate tolerant mutant (PM) strains of the cellulolytic bacterium C. thermocellum was developed to quantify growth kinetics in standard media and the extent of inhibition to a Populus hydrolysate. The PM was characterized by a higher growth rate (μmax=1.223 vs. 0.571 h(-1)) and less inhibition (KI,gen=0.991 vs. 0.757) in 10% v/v Populus hydrolysate compared to the WT. In 17.5% v/v Populus hydrolysate inhibition of PM increased slightly (KI,gen=0.888), whereas the WT was strongly inhibited and did not grow in a reproducible manner. Of the individual inhibitors tested, 4-hydroxybenzoic acid was the most inhibitory, followed by galacturonic acid. The PM did not have a greater ability to detoxify the hydrolysate than the WT. Copyright © 2013 Elsevier Ltd. All rights reserved.

  10. Lipase production from a wild (LPF-5) and a mutant (HN1) strain of ...

    African Journals Online (AJOL)

    Lipase production from a wild (LPF-5) and a mutant (HN1) strain of Aspergillus niger. ... Several physical parameters (carbon source, nitrogen source, pH, ... for the development of industrial biotechnology for production of extracellular lipase.

  11. Sabin and wild type polioviruses from children who presented with ...

    African Journals Online (AJOL)

    Conclusion: This study further confirms the presence of Sabin and wild-type poliovirus among children in Nigeria. The isolation of Sabin strain of poliovirus is advantageous to the polio eradication program as it is capable of inducing natural immunity in susceptible hosts. Transmission of wild-type poliovirus among children ...

  12. Trichoderma reesei xylanase 5 is defective in the reference strain QM6a but functional alleles are present in other wild-type strains.

    Science.gov (United States)

    Ramoni, Jonas; Marchetti-Deschmann, Martina; Seidl-Seiboth, Verena; Seiboth, Bernhard

    2017-05-01

    Trichoderma reesei is a paradigm for the regulation and industrial production of plant cell wall-degrading enzymes. Among these, five xylanases, including the glycoside hydrolase (GH) family 11 XYN1 and XYN2, the GH10 XYN3, and the GH30 XYN4 and XYN6, were described. By genome mining and transcriptome analysis, a further putative xylanase, encoded by xyn5, was identified. Analysis of xyn5 from the genome-sequenced reference strain T. reesei QM6a shows that it encodes a non-functional, truncated form of XYN5. However, non-truncated orthologues are present in other genome sequenced Trichoderma spp., and sequencing of xyn5 in other T. reesei wild-type isolates shows that they harbor a putative functional xyn5 allele. In silico analysis and 3D modeling revealed that the encoded XYN5 has significant structural similarities to xylanases of the GH11 family, including a GH-typical substrate binding groove and a carboxylate pair in the active site. The xyn5 of wild-type strain TUCIM1282 was recombinantly expressed in a T. reesei strain with a (hemi)cellulase-free background and the corresponding protein purified to apparent homogeneity. The pH and temperature optima and the kinetic parameters of the purified XYN5 were pH 4, 50 °C, and V max  = 2646 nkat/mg with a K m of 9.68 mg/ml. This functional xyn5 allele was used to replace the mutated version which led to an overall increase of the xylanolytic activity. These findings are of particular importance as GH11 xylanases are of high biotechnological relevance, and T. reesei is one of the main industrial producers of such lignocellulose-degrading enzymes.

  13. Comparative Study of Nonautolytic Mutant and Wild-Type Strains of Coprinopsis cinerea Supports an Important Role of Glucanases in Fruiting Body Autolysis.

    Science.gov (United States)

    Liu, Zhonghua; Niu, Xin; Wang, Jun; Zhang, Wenming; Yang, Mingmei; Liu, Cuicui; Xiong, Yuanjing; Zhao, Yan; Pei, Siyu; Qin, Qin; Zhang, Yu; Yu, Yuan; Yuan, Sheng

    2015-11-04

    Autolysis of Coprinopsis cinerea fruiting bodies affects its commercial value. In this study, a mutant of C. cinerea that exhibits pileus expansion without pileus autolysis was obtained using ultraviolet mutagenesis. This suggests that pileus expansion and pileus autolysis involve different enzymes or proteins. Among the detected hydrolytic enzymes, only β-1,3-glucanase activity increased with expansion and autolysis of pilei in the wild-type strain, but the increase was abolished in the mutant. This suggests that β-1,3-glucanases plays a major role in the autolysis. Although there are 43 possible β-1,3-glucoside hydrolases genes, only 4 known genes, which have products that are thought to act synergistically to degrade the β-1,3-glucan backbone of cell walls during fruiting body autolysis, and an unreported gene were upregulated during pileus expansion and autolysis in the wild-type stain but were suppressed in the mutant. This suggests that expression of these β-1,3-glucanases is potentially controlled by a single regulatory mechanism.

  14. Genetic analysis of the porcine group B rotavirus NSP2 gene from wild-type Brazilian strains

    Directory of Open Access Journals (Sweden)

    K.C. Médici

    2010-01-01

    Full Text Available Group B rotaviruses (RV-B were first identified in piglet feces, being later associated with diarrhea in humans, cattle, lambs, and rats. In human beings, the virus was only described in China, India, and Bangladesh, especially infecting adults. Only a few studies concerning molecular analysis of the RV-B NSP2 gene have been conducted, and porcine RV-B has not been characterized. In the present study, three porcine wild-type RV-B strains from piglet stool samples collected from Brazilian pig herds were used for analysis. PAGE results were inconclusive for those samples, but specific amplicons of the RV-B NSP2 gene (segment 8 were obtained in a semi-nested PCR assay. The three porcine RV-B strains showed the highest nucleotide identity with the human WH1 strain and the alignments with other published sequences resulted in three groups of strains divided according to host species. The group of human strains showed 92.4 to 99.7% nucleotide identity while the porcine strains of the Brazilian RV-B group showed 90.4 to 91.8% identity to each other. The identity of the Brazilian porcine RV-B strains with outer sequences consisting of group A and C rotaviruses was only 35.3 to 38.8%. A dendrogram was also constructed to group the strains into clusters according to host species: human, rat, and a distinct third cluster consisting exclusively of the Brazilian porcine RV-B strains. This is the first study of the porcine RV-B NSP2 gene that contributes to the partial characterization of this virus and demonstrates the relationship among RV-B strains from different host species.

  15. Quorum quenching by an N-acyl-homoserine lactone acylase from Pseudomonas aeruginosa PAO1

    NARCIS (Netherlands)

    Sio, CF; Otten, LG; Cool, RH; Diggle, SP; Braun, PG; Daykin, M; Camara, M; Williams, P; Quax, WJ; Bos, R

    The virulence of the opportunistic human pathogen Pseudomonas aeruginosa PAO1 is controlled by an N-acyl-homoserine lactone (AHL)-dependent quorum-sensing system. During functional analysis of putative acylase genes in the P. aeruginosa PAO1 genome, the PA2385 gene was found to encode an acylase

  16. Detection and differentiation of wild-type and vaccine strains of canine distemper virus by a duplex reverse transcription polymerase chain reaction.

    Science.gov (United States)

    Dong, X Y; Li, W H; Zhu, J L; Liu, W J; Zhao, M Q; Luo, Y W; Chen, J D

    2015-01-01

    Canine distemper virus (CDV) is the cause of canine distemper (CD) which is a severe and highly contagious disease in dogs. In the present study, a duplex reverse transcription polymerase chain reaction (RT-PCR) method was developed for the detection and differentiation of wild-type and vaccine strains of CDV. Four primers were designed to detect and discriminate the two viruses by generating 638- and 781-bp cDNA products, respectively. Furthermore, the duplex RT-PCR method was used to detect 67 field samples suspected of CD from Guangdong province in China. Results showed that, 33 samples were to be wild-type-like. The duplex RT-PCR method exhibited high specificity and sensitivity which could be used to effectively detect and differentiate wild-type and vaccine CDV, indicating its use for clinical detection and epidemiological surveillance.

  17. Life table and male mating competitiveness of wild type and of a chromosome mutation strain of Tetranychus urticae in relation to genetic pest control

    International Nuclear Information System (INIS)

    Feldmann, A.M.

    1981-01-01

    Males of Tetranychus urticae Koch (Acarina: Tetranychidae) from a strain, homozygous for a structural chromosome mutation (T) were competed against males from a standard (wild-type) strain for mating of wild-type fermales. The T-males exhibited only a slight reduction in male mating competitiveness. The debilitating influence of ageing on male mating competitiveness was equal for males of both strains. Life-table studies on both strains showed that the net reproductive rate (R 0 ) of the T-strain was 53.3, which was higher than the R 0 -value of the standard strain (43.3). This difference was caused by the higher rate of age-dependent mortality of adult females of the standard strain. Also differences between both strains in the total sex-ratio were observed; the T-strain produced significantly fewer males and more females than the standard strain. The mean generation time of both strains was almost equal (14 days). The values of the intrinsic rate of increase (rsub(m)) for the T-strain and the standard strain were 0.286 and 0.273, respectively. The life-table data correspond well with those published elsewhere on Tetranychus urticae. The feasibility of T-strains for application in genetic pest control considering the use of structural chromosome mutations as a 'transport mechanism' for conditional lethals is discussed. (orig.)

  18. Resistance of Pseudomonas aeruginosa PAO to nalidixic acid and low levels of beta-lactam antibiotics: mapping of chromosomal genes.

    Science.gov (United States)

    Rella, M; Haas, D

    1982-01-01

    Resistance to high concentrations of nalidixic acid in Pseudomonas aeruginosa PAO was due to mutations in one locus designated nalA, which was mapped by transduction between hex-9001 and leu-10. The nalA mutants were cross-resistant to pipemidic acid, a nalidixic acid analog, at relatively low concentrations. Replicative DNA synthesis was resistant to both drugs in permeabilized cells of nalA mutants. A locus coding for low-level resistance to nalidixic acid, nalB, was cotransducible with pyrB, proC, and met-28. The nalB mutants were also resistant to low levels of pipemidic acid, novobiocin, and beta-lactam antibiotics (e.g., carbenicillin, azlocillin, and cefsulodin), but not to other drugs, such as gentamicin, rifampin, kanamycin, or tetracycline. In nalB mutants, DNA replication showed wild-type sensitivity to nalidixic acid, whereas carbenicillin-induced filamentation required higher drug levels than in the wild-type strain. Thus, nalB mutations appear to decrease cell permeability to some antibiotics. The sensitivity of replicative DNA synthesis to nalidixic acid and novobiocin was very similar in P. aeruginosa and Escherichia coli; by contrast, the concentrations of these drugs needed to inhibit growth of P. aeruginosa were higher than those reported for E. coli by one or two orders of magnitude. PMID:6821455

  19. Wild-type MIC distributions for aminoglycoside and cyclic polypeptide antibiotics used for treatment of Mycobacterium tuberculosis infections.

    Science.gov (United States)

    Juréen, P; Angeby, K; Sturegård, E; Chryssanthou, E; Giske, C G; Werngren, J; Nordvall, M; Johansson, A; Kahlmeter, G; Hoffner, S; Schön, T

    2010-05-01

    The aminoglycosides and cyclic polypeptides are essential drugs in the treatment of multidrug-resistant tuberculosis, underscoring the need for accurate and reproducible drug susceptibility testing (DST). The epidemiological cutoff value (ECOFF) separating wild-type susceptible strains from non-wild-type strains is an important but rarely used tool for indicating susceptibility breakpoints against Mycobacterium tuberculosis. In this study, we established wild-type MIC distributions on Middlebrook 7H10 medium for amikacin, kanamycin, streptomycin, capreomycin, and viomycin using 90 consecutive clinical isolates and 21 resistant strains. Overall, the MIC variation between and within runs did not exceed +/-1 MIC dilution step, and validation of MIC values in Bactec 960 MGIT demonstrated good agreement. Tentative ECOFFs defining the wild type were established for all investigated drugs, including amikacin and viomycin, which currently lack susceptibility breakpoints for 7H10. Five out of seven amikacin- and kanamycin-resistant isolates were classified as susceptible to capreomycin according to the current critical concentration (10 mg/liter) but were non-wild type according to the ECOFF (4 mg/liter), suggesting that the critical concentration may be too high. All amikacin- and kanamycin-resistant isolates were clearly below the ECOFF for viomycin, and two of them were below the ECOFF for streptomycin, indicating that these two drugs may be considered for treatment of amikacin-resistant strains. Pharmacodynamic indices (peak serum concentration [Cmax]/MIC) were more favorable for amikacin and viomycin compared to kanamycin and capreomycin. In conclusion, our data emphasize the importance of establishing wild-type MIC distributions for improving the quality of drug susceptibility testing against Mycobacterium tuberculosis.

  20. Labeled Azospirillum brasilense wild type and excretion-ammonium strains in association with barley roots.

    Science.gov (United States)

    Santos, Adrian Richard Schenberger; Etto, Rafael Mazer; Furmam, Rafaela Wiegand; Freitas, Denis Leandro de; Santos, Karina Freire d'Eça Nogueira; Souza, Emanuel Maltempi de; Pedrosa, Fábio de Oliveira; Ayub, Ricardo Antônio; Steffens, Maria Berenice Reynaud; Galvão, Carolina Weigert

    2017-09-01

    Soil bacteria colonization in plants is a complex process, which involves interaction between many bacterial characters and plant responses. In this work, we labeled Azospirillum brasilense FP2 (wild type) and HM053 (excretion-ammonium) strains by insertion of the reporter gene gusA-kanamycin into the dinitrogenase reductase coding gene, nifH, and evaluated bacteria colonization in barley (Hordeum vulgare). In addition, we determined inoculation effect based on growth promotion parameters. We report an uncommon endophytic behavior of A. brasilense Sp7 derivative inside the root hair cells of barley and highlight the promising use of A. brasilense HM053 as plant growth-promoting bacterium. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  1. Synthesis of the d,I-HM-PAO and formulation of nucleo-equipment for the obtention of {sup 99m} Tc-(d,I)-HM-PAO; Sintesis del d,I-HM-PAO y formulacion de nucleo-equipos para la obtencion de {sup 99m} Tc-(d,I)-HM-PAO

    Energy Technology Data Exchange (ETDEWEB)

    Lezama C, J; Ferro F, G; Alcazar A, P

    1991-09-15

    Most brain imaging radiopharmaceuticals are conventional hydrophilic compounds that are excluded from entering the normal brain by an intact blood-brain barrier (BBB). Under pathologic conditions, the barrier is disrupted and radiotracer concentrates in the leisure for positive identification. {sup 99m} Tc- hexa methyl propylene amine oxime ({sup 99} {sup m} Tc-HM-PAO) is a newer-type lipophilic agent that enter the normal brain through an intact BBB. Studies with this agent offer the promise of measuring cerebral perfusion in the normal and diseased brain. In this paper we present the synthesis and Tc-99m labelling of d,I-HM-PAO. The synthesis of the ligand was carried out by condensation of two molecular equivalents of butanedione monoxime with one molecular equivalent of 1,3 propanediamine provided a bis imine intermediate, which was reduced with sodium borohydride to get the meso and d,I diastereoisomers of HM-PAO. Separation of these was achieved by fractional crystallization. {sup 99m} Tc-(d,I)HM-PAO was obtained by stannous ion reduction of Mo-99/Tc-99m generator eluate in the presence of the ligand. Complex radiochemical purity was determined by instant thin layer chromatography and paper chromatography. Finally, we obtained {sup 99m} Tc-(d,I)HM-PAO with a high radiochemical yield, in excess of 90%. However, for subsequent clinical studies the preparation has to be done a few minutes before application because our product has a low stability. (Author)

  2. Wild-Type MIC Distributions for Aminoglycoside and Cyclic Polypeptide Antibiotics Used for Treatment of Mycobacterium tuberculosis Infections▿

    Science.gov (United States)

    Juréen, P.; Ängeby, K.; Sturegård, E.; Chryssanthou, E.; Giske, C. G.; Werngren, J.; Nordvall, M.; Johansson, A.; Kahlmeter, G.; Hoffner, S.; Schön, T.

    2010-01-01

    The aminoglycosides and cyclic polypeptides are essential drugs in the treatment of multidrug-resistant tuberculosis, underscoring the need for accurate and reproducible drug susceptibility testing (DST). The epidemiological cutoff value (ECOFF) separating wild-type susceptible strains from non-wild-type strains is an important but rarely used tool for indicating susceptibility breakpoints against Mycobacterium tuberculosis. In this study, we established wild-type MIC distributions on Middlebrook 7H10 medium for amikacin, kanamycin, streptomycin, capreomycin, and viomycin using 90 consecutive clinical isolates and 21 resistant strains. Overall, the MIC variation between and within runs did not exceed ±1 MIC dilution step, and validation of MIC values in Bactec 960 MGIT demonstrated good agreement. Tentative ECOFFs defining the wild type were established for all investigated drugs, including amikacin and viomycin, which currently lack susceptibility breakpoints for 7H10. Five out of seven amikacin- and kanamycin-resistant isolates were classified as susceptible to capreomycin according to the current critical concentration (10 mg/liter) but were non-wild type according to the ECOFF (4 mg/liter), suggesting that the critical concentration may be too high. All amikacin- and kanamycin-resistant isolates were clearly below the ECOFF for viomycin, and two of them were below the ECOFF for streptomycin, indicating that these two drugs may be considered for treatment of amikacin-resistant strains. Pharmacodynamic indices (peak serum concentration [Cmax]/MIC) were more favorable for amikacin and viomycin compared to kanamycin and capreomycin. In conclusion, our data emphasize the importance of establishing wild-type MIC distributions for improving the quality of drug susceptibility testing against Mycobacterium tuberculosis. PMID:20237102

  3. Reverse spillover of avian viral vaccine strains from domesticated poultry to wild birds.

    Science.gov (United States)

    Rohaim, M A; El Naggar, R F; Helal, A M; Hussein, H A; Munir, Muhammad

    2017-06-16

    Transmission of viruses from the commercial poultry to wild birds is an emerging paradigm of livestock-wildlife interface. Here, we report the identification and isolation of vaccine strains of avian paramyxovirus serotype 1 (APMV1) and avian coronaviruses (ACoV) from different wild bird species across eight Egyptian governorates between January 2014 and December 2015. Surveillance of avian respiratory viruses in free-ranging wild birds (n=297) identified three species that harboured or excreted APMV1 and ACoVs. Genetic characterization and phylogenetic analysis of recovered viruses revealed a close association with the most widely utilized vaccine strains in the country. These results highlight the potential spillover of vaccine-viruses probably due to extensive use of live-attenuated vaccines in the commercial poultry, and close interaction between domesticated and wild bird populations. Further exploring the full spectrum of vaccine-derived viral vaccine strains in wild birds might help to assess the emergence of future wild-birds origin viruses. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

  4. Methanol Extract from Anogeissus leiocarpus (DC Guill. et Perr. (Combretaceae Stem Bark Quenches the Quorum Sensing of Pseudomonas aeruginosa PAO1

    Directory of Open Access Journals (Sweden)

    Vincent Ouedraogo

    2016-10-01

    Full Text Available Background: Due to its extensive arsenal of virulence factors and inherent resistance to antibiotics, Pseudomonas aeruginosa is a threat particularly in immunocompromised patients. Considering the central role of quorum sensing in the production of virulence factors, inhibition of bacterial communication mechanism constitute an opportunity to attenuate pathogenicity of bacteria resistant to available antibiotics. Our study aimed to assess the anti-quorum sensing activity of Anogeissus leiocarpus, traditionally used in Burkina Faso, for the treatment of infected burn wounds. Methods: Investigations were carried out on methanol extract from A. leiocarpus stem bark. The reporter strains Chromobacterium violaceum CV026 and P. aeruginosa PAO1 derivatives were used to evidence any interference with the bacterial quorum sensing and expression of related genes. P. aeruginosa PAO1 was used to measure the impact on pyocyanin production. Results: At a sub-inhibitory concentration (100 µg/mL, A. leiocarpus methanol extract quenched the quorum sensing mechanism of P. aeruginosa PAO1 by down-streaming the rhlR gene, with a subsequent reduction of pyocyanin production. Moreover, the antioxidant polyphenols evidenced are able to reduce the oxidative stress induced by pyocyanin. Conclusion: The antioxidant and anti-quorum sensing activities of A. leiocarpus stem bark could justify its traditional use in the treatment of infected burn wounds.

  5. The retention mechanism of technetium-99m-HM-PAO

    DEFF Research Database (Denmark)

    Neirinckx, R D; Burke, J F; Harrison, R C

    1988-01-01

    Preparations of d,l- and meso-hexamethylpropyleneamine oxime (HM-PAO) labeled with technetium-99m were added to rat brain homogenates diluted with phosphate buffer (1:10). The conversion of d,l-HM-PAO to hydrophilic forms took place with an initial rate constant of 0.12 min-1. Incubation of the b......Preparations of d,l- and meso-hexamethylpropyleneamine oxime (HM-PAO) labeled with technetium-99m were added to rat brain homogenates diluted with phosphate buffer (1:10). The conversion of d,l-HM-PAO to hydrophilic forms took place with an initial rate constant of 0.12 min-1. Incubation....... This correspondence of values supports the notion that GSH may be important for the in vivo conversion of 99mTc-labeled HM-PAO to hydrophilic forms and may be the mechanism of trapping in brain and other cells. A kinetic model for the trapping of d,l- and meso-HM-PAO in tissue is developed that is based on data...

  6. Multiple antibiotic susceptibility of polyphosphate kinase mutants (ppk1 and ppk2 from Pseudomonas aeruginosa PAO1 as revealed by global phenotypic analysis

    Directory of Open Access Journals (Sweden)

    Javiera Ortiz-Severín

    2015-01-01

    Full Text Available BACKGROUND: Pseudomonas aeruginosa is known to be a multidrug resistant opportunistic pathogen. Particularly, P. aeruginosa PAO1 polyphosphate kinase mutant (ppk1 is deficient in motility, quorum sensing, biofilm formation and virulence FINDINGS: By using Phenotypic Microarrays (PM we analyzed near 2000 phenotypes of P. aeruginosa PAO1 polyP kinase mutants (ppk1 and ppk2. We found that both ppk mutants shared most of the phenotypic changes and interestingly many of them related to susceptibility toward numerous and different type of antibiotics such as Ciprofloxacin, Chloramphenicol and Rifampicin CONCLUSIONS: Combining the fact that ppk1 mutants have reduced virulence and are more susceptible to antibiotics, polyP synthesis and particularly PPK1, is a good target for the design of molecules with anti-virulence and anti-persistence properties.

  7. Development of a multiplex amplification refractory mutation system reverse transcription polymerase chain reaction assay for the differential diagnosis of Feline leukemia virus vaccine and wild strains.

    Science.gov (United States)

    Ho, Chia-Fang; Chan, Kun-Wei; Yang, Wei-Cheng; Chiang, Yu-Chung; Chung, Yang-Tsung; Kuo, James; Wang, Chi-Young

    2014-07-01

    A multiplex amplification refractory mutation system reverse transcription polymerase chain reaction (ARMS RT-PCR) was developed for the differential diagnosis of Feline leukemia virus (FeLV) vaccine and wild-type strains based on a point mutation between the vaccine strain (S) and the wild-type strain (T) located in the p27 gene. This system was further upgraded to obtain a real-time ARMS RT-PCR (ARMS qRT-PCR) with a high-resolution melt analysis (HRMA) platform. The genotyping of various strains of FeLV was determined by comparing the HRMA curves with the defined wild-type FeLV (strain TW1), and the results were expressed as a percentage confidence. The detection limits of ARMS RT-PCR and ARMS qRT-PCR combined with HRMA were 100 and 1 copies of transcribed FeLV RNA per 0.5 ml of sample, respectively. No false-positive results were obtained with 6 unrelated pathogens and 1 feline cell line. Twelve FeLV Taiwan strains were correctly identified using ARMS qRT-PCR combined with HRMA. The genotypes of the strains matched the defined FeLV wild-type strain genotype with at least 91.17% confidence. A higher degree of sequence polymorphism was found throughout the p27 gene compared with the long terminal repeat region. In conclusion, the current study describes the phylogenetic relationship of the FeLV Taiwan strains and demonstrates that the developed ARMS RT-PCR assay is able to be used to detect the replication of a vaccine strain that has not been properly inactivated, thus acting as a safety check for the quality of FeLV vaccines.

  8. Real-time reverse transcription-polymerase chain reaction assays for identification of wild poliovirus 1 & 3.

    Science.gov (United States)

    Sharma, Deepa K; Nalavade, Uma P; Deshpande, Jagadish M

    2015-10-01

    The poliovirus serotype identification and intratypic differentiation by real-time reverse transcription-polymerase chain reaction (rRT-PCR) assay is suitable for serotype mixtures but not for intratypic mixtures of wild and vaccine poliovirus strains. This study was undertaken to develop wild poliovirus 1 and 3 (WPV1 and WPV3) specific rRT-PCR assays for use. Specific primers and probes for rRT-PCR were designed based on VP1 sequences of WPV1 and WPV3 isolated in India since 2000. The specificity of the rRT-PCR assays was evaluated using WPV1 and WPV3 of different genetic lineages, non-polio enteroviruses (NPEVs) and mixtures of wild/wild and wild/Sabin vaccine strains. The sensitivity of the assays was determined by testing serial 10-fold dilutions of wild poliovirus 1 and 3 stock suspensions of known titre. No cross-reactivity with Sabin strains, intertypic wild poliovirus isolates or 27 types of NPEVs across all the four Enterovirus species was found for both the wild poliovirus 1 and 3 rRT-PCR assays. All WPV1 and WPV3 strains isolated since 2000 were successfully amplified. The rRT-PCR assays detected 10 4.40 CCID 50 /ml of WPV1 and 10 4.00 CCID 50 /ml of WPV3, respectively either as single isolate or mixture with Sabin vaccine strains or intertypic wild poliovirus. rRT-PCR assays for WPV1 and WPV3 have been validated to detect all the genetic variations of the WPV1 and WPV3 isolated in India for the last decade. When used in combination with the current rRT-PCR assay testing was complete for confirmation of the presence of wild poliovirus in intratypic mixtures.

  9. Pseudomonas aeruginosa AlgR Phosphorylation Status Differentially Regulates Pyocyanin and Pyoverdine Production

    Directory of Open Access Journals (Sweden)

    Alexander S. Little

    2018-01-01

    Full Text Available Pseudomonas aeruginosa employs numerous, complex regulatory elements to control expression of its many virulence systems. The P. aeruginosa AlgZR two-component regulatory system controls the expression of several crucial virulence phenotypes. We recently determined, through transcriptomic profiling of a PAO1 ΔalgR mutant strain compared to wild-type PAO1, that algZR and hemCD are cotranscribed and show differential iron-dependent gene expression. Previous expression profiling was performed in strains without algR and revealed that AlgR acts as either an activator or repressor, depending on the gene. Thus, examination of P. aeruginosa gene expression from cells locked into different AlgR phosphorylation states reveals greater physiological relevance. Therefore, gene expression from strains carrying algR alleles encoding a phosphomimetic (AlgR D54E or a phosphoablative (AlgR D54N form were compared by microarray to PAO1. Transcriptome analyses of these strains revealed 25 differentially expressed genes associated with iron siderophore biosynthesis or heme acquisition or production. The PAO1 algR D54N mutant produced lower levels of pyoverdine but increased expression of the small RNAs prrf1 and prrf2 compared to PAO1. In contrast, the algR D54N mutant produced more pyocyanin than wild-type PAO1. On the other hand, the PAO1 algR D54E mutant produced higher levels of pyoverdine, likely due to increased expression of an iron-regulated gene encoding the sigma factor pvdS, but it had decreased pyocyanin production. AlgR specifically bound to the prrf2 and pvdS promoters in vitro. AlgR-dependent pyoverdine production was additionally influenced by carbon source rather than the extracellular iron concentration per se. AlgR phosphorylation effects were also examined in a Drosophila melanogaster feeding, murine acute pneumonia, and punch wound infection models. Abrogation of AlgR phosphorylation attenuated P. aeruginosa virulence in these infection

  10. Synthesis of the d,I-HM-PAO and formulation of nucleo-equipment for the obtention of 99m Tc-(d,I)-HM-PAO

    International Nuclear Information System (INIS)

    Lezama C, J.; Ferro F, G.; Alcazar A, P.

    1991-09-01

    Most brain imaging radiopharmaceuticals are conventional hydrophilic compounds that are excluded from entering the normal brain by an intact blood-brain barrier (BBB). Under pathologic conditions, the barrier is disrupted and radiotracer concentrates in the leisure for positive identification. 99m Tc- hexa methyl propylene amine oxime ( 99 m Tc-HM-PAO) is a newer-type lipophilic agent that enter the normal brain through an intact BBB. Studies with this agent offer the promise of measuring cerebral perfusion in the normal and diseased brain. In this paper we present the synthesis and Tc-99m labelling of d,I-HM-PAO. The synthesis of the ligand was carried out by condensation of two molecular equivalents of butanedione monoxime with one molecular equivalent of 1,3 propanediamine provided a bis imine intermediate, which was reduced with sodium borohydride to get the meso and d,I diastereoisomers of HM-PAO. Separation of these was achieved by fractional crystallization. 99m Tc-(d,I)HM-PAO was obtained by stannous ion reduction of Mo-99/Tc-99m generator eluate in the presence of the ligand. Complex radiochemical purity was determined by instant thin layer chromatography and paper chromatography. Finally, we obtained 99m Tc-(d,I)HM-PAO with a high radiochemical yield, in excess of 90%. However, for subsequent clinical studies the preparation has to be done a few minutes before application because our product has a low stability. (Author)

  11. Pseudomonas aeruginosa mutations in lasI and rhlI quorum sensing systems result in milder chronic lung infection

    DEFF Research Database (Denmark)

    Wu, H; Song, Z; Givskov, Michael

    2001-01-01

    To understand the importance of quorum sensing in chronic Pseudomonas aeruginosa lung infection, the in vivo pathogenic effects of the wild-type P. aeruginosa PAO1 and its double mutant, PAO1 lasI rhlI, in which the signal-generating parts of the quorum sensing systems are defective were compared....... The rat model of P. aeruginosa lung infection was used in the present study. The rats were killed on days 3, 7, 14 and 28 after infection with the P. aeruginosa strains. The results showed that during the early stages of infection, the PAO1 double mutant induced a stronger serum antibody response, higher...... number of lung bacteria, and minor serum IgG and IgG1 responses but increased lung interferon gamma production were detected in the group infected with the PAO1 double mutant when compared with the PAO1-infected group. Delayed immune responses were observed in the PAO1-infected group and they might...

  12. Pseudomonas aeruginosa mutations in lasl and rhll quorum sensing systems result in milder chronic lung infection

    DEFF Research Database (Denmark)

    Wu, H.; Song, Z.J.; Givskov, Michael Christian

    2001-01-01

    To understand the importance of quorum sensing in chronic Pseudomonas aeruginosa lung infection, the in vivo pathogenic effects of the wild-type P aeruginosa PAO1 and its double mutant, PAO1 lasI rhlI, in which the signal-generating parts of the quorum sensing systems are defective were compared....... The rat model of P. aeruginosa lung infection was used in the present study. The rats were killed on days 3, 7, 14 and 28 after infection with the P. aeruginosa strains. The results showed that during the early stages of infection, the PAO1 double mutant induced a stronger serum antibody response, higher...... number of lung bacteria, and minor serum IgG and IgG1 responses but increased lung interferon gamma production were detected in the group infected with the PAO1 double mutant when compared with the PAO1-infected group. Delayed immune responses were observed in the PAO1-infected group and they might...

  13. Comparison of genome engineering using the CRISPR-Cas9 system in C. glabrata wild-type and lig4 strains.

    Science.gov (United States)

    Cen, Yuke; Timmermans, Bea; Souffriau, Ben; Thevelein, Johan M; Van Dijck, Patrick

    2017-10-01

    Candida glabrata is reported as the second most prevalent human opportunistic fungal pathogen in North America and is threatening patients all over the world. Its incidence is rising, while it has developed resistance to the most widely used antifungal drugs, necessitating new approaches based on better insight into the biology of the organism. Despite its close phylogenetic relationship with Saccharomyces cerevisiae, generating precise genomic alterations in this species is problematic. Previously we have shown that deletion of LIG4, which encodes an enzyme involved in Non-Homologous End Joining (NHEJ), strongly enhances the probability of obtaining correctly modified transformants. In this work we used the Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) and CRISPR associated protein 9 (Cas9) system to genetically engineer the C. glabrata genome, targeting the genes ADE2, MET15 and SOK2, located on different chromosomes. We used the CRISPR-Cas9 technology to replace the open reading frame (ORF) by the SAT1 selective marker or introduced a premature stop codon in ADE2 and MET15, as they are easily scored by their adenine or methionine auxotrophy, respectively. The SOK2 gene was modified by insertion of a triple HA-tag sequence and the transformants were verified in a western blot. The CRISPR-Cas9 mediated targeting efficiency varies depending on the gene targeted and the genetic modification performed. We show that CRISPR-Cas9 mediated genome editing is more efficient than the conventional method in the wild-type strain, moreover it has the big advantage being marker-free. In previous work, we showed that the targeting efficiency is highly increased in the lig4Δ strain using the conventional way to delete genes in C. glabrata. Using the CRISPR-Cas9 system in this strain, the percentage of correct transformants is consistently higher compared to the wild-type strain. This indicates that using the lig4 mutant as such is already a strong

  14. Sabin and wild type polioviruses from children who presented with acute flaccid paralysis in Nigeria.

    Science.gov (United States)

    Adedeji, A O; Okonko, I O; Adu, F D

    2012-09-01

    Sensitive poliovirus surveillance to detect vaccine-derived-polioviruses will continue to increase in importance. Isolating and identifying poliovirus strains from children of pediatrics age in Nigeria. A total of 120 fecal samples were randomly collected from children under the age of five who presented with acute flaccid paralysis. Samples were tested by tissue culture technique and further characterized by intratypic differentiation testing using ELISA and PCR methods. The study confirmed the presence of 22(18.3%) enteroviral isolates comprising 19(86.4%) polioviruses and 3(13.6%) non-polio enteroviruses. These 19 polioviruses include: Sabin-type poliovirus-1 (15.8%), poliovirus-2 (10.5%), poliovirus-3 (10.5%) and wild-type poliovirus-1 (63.2%) isolates. It showed that poliovirus infection was higher in children ages 6-11 months (18.9%), females (18.4%), northern states (91.0%) with no vaccination record (75.0%). Wild-type poliovirus-1 was isolated from the stool samples of 12(54.6%) children from northern states and in all age groups except 18-23 months. No significant differences (P >0.05) between poliovirus infection and age (18.9% vs. 17.7%; 81.9% vs. 18.2%) and sex (18.3% vs. 18.4%). There was significant differences (Pvaccination (75.0% vs. 0.0%). No wild-type poliovirus was found in those with complete vaccination. This study further confirms the presence of Sabin and wild-type poliovirus among children in Nigeria. The isolation of Sabin strain of poliovirus is advantageous to the polio eradication program as it is capable of inducing natural immunity in susceptible hosts. Transmission of wild-type poliovirus among children with incomplete vaccination poses a serious threat to polio eradication program in Nigeria. Environmental and serological surveillance with larger sample size are important for monitoring poliovirus circulation in Nigeria.

  15. The Phenotypic Effects of Royal Jelly on Wild-Type D. melanogaster Are Strain-Specific.

    Directory of Open Access Journals (Sweden)

    Stefanie L Morgan

    Full Text Available The role for royal jelly (RJ in promoting caste differentiation of honeybee larvae into queens rather than workers is well characterized. A recent study demonstrated that this poorly understood complex nutrition drives strikingly similar phenotypic effects in Drosophila melanogaster, such as increased body size and reduced developmental time, making possible the use of D. melanogaster as a model system for the genetic analysis of the cellular mechanisms underlying RJ and caste differentiation. We demonstrate here that RJ increases the body size of some wild-type strains of D. melanogaster but not others, and report significant delays in developmental time in all flies reared on RJ. These findings suggest that cryptic genetic variation may be a factor in the D. melanogaster response to RJ, and should be considered when attempting to elucidate response mechanisms to environmental changes in non-honeybee species.

  16. Development of an indirect enzyme-linked immunosorbent assay (ELISA) to differentiate antibodies against wild-type porcine reproductive and respiratory syndrome from the vaccine strain TJM-F92 based on a recombinant Nsp2 protein.

    Science.gov (United States)

    Wang, X X; Wang, F X; Li, Z G; Wen, Y J; Wang, X; Song, N; Wu, H

    2018-01-01

    An accurate ELISA method to differentiate pigs infected with wild-type porcine reproductive and respiratory syndrome (PRRSV) strains from vaccinated ones would help to monitor PRRSV vaccination compliance. The recombinant protein GST-d120aa derived from the continuous deletion of 120 amino acids in the non-structural protein 2 region of the modified-live vaccine strain TJM-F92 was used to develop an indirect enzyme-linked immunosorbent assay (d120-ELISA) for differentiating serum antibodies against TJM-F92 from other PRRSV strains. At the optimized cut-off value which was calculated at an S/P of 0.25, it yielded a sensitivity of 90.7% and a specificity of 95.1%. Cross-reactivity tests suggested that the d120-ELISA was PRRSV-specific. Coefficient of variations of the repeatability tests ranged between 1.41-17.02%. The results suggest that the d120-ELISA is suitable for differentiating animals infected with wild-type strains from those immunized with MLV TJM-F92. Copyright © 2017. Published by Elsevier B.V.

  17. Detection by hemi-nested reverse transcription polymerase chain reaction and genetic characterization of wild type strains of Canine distemper virus in suspected infected dogs.

    Science.gov (United States)

    Di Francesco, Cristina E; Di Francesco, Daniela; Di Martino, Barbara; Speranza, Roberto; Santori, Domenico; Boari, Andrea; Marsilio, Fulvio

    2012-01-01

    A new highly sensitive and specific hemi-nested reverse transcription polymerase chain reaction (RT-PCR) assay was applied to detect nucleoprotein (NP) gene of Canine distemper virus (CDV) in samples collected from dogs showing respiratory, gastrointestinal, and neurological signs. Thirty-eight out of 86 samples were positive suggesting that despite the vaccination, canine distemper may still represent a high risk to the canine population. The 968 base pair (bp) fragments from the hemagglutinin (H) gene of 10 viral strains detected in positive samples were amplified and analyzed by restriction fragment length polymorphism (RFLP) using AluI and PsiI enzymes in order to differentiate among vaccine and wild-type CDV strains and to characterize the field viral strains. The products of the both enzymatic digestions allowed identification all viruses as wild strains of CDV. In addition, the RFLP analysis with AluI provided additional information about the identity level among the strains analyzed on the basis of the positions of the cleavage site in the nucleotide sequences of the H gene. The method could be a more useful and simpler method for molecular studies of CDV strains.

  18. The wild type as concept and in experimental practice: A history of its role in classical genetics and evolutionary theory.

    Science.gov (United States)

    Holmes, Tarquin

    2017-06-01

    Wild types in genetics are specialised strains of laboratory experimental organism which principally serve as standards against which variation is measured. As selectively inbred lineages highly isolated from ancestral wild populations, there appears to be little wild or typical about them. I will nonetheless argue that they have historically been successfully used as stand-ins for nature, allowing knowledge produced in the laboratory to be extrapolated to the natural world. In this paper, I will explore the 19th century origins of the wild type concept, the theoretical and experimental innovations which allowed concepts and organisms to move from wild nature to laboratory domestication c. 1900 (resulting in the production of standardised lab strains), and the conflict among early geneticists between interactionist and atomist accounts of wild type, which would eventually lead to the conceptual disintegration of wild types and the triumph of genocentrism and population genetics. I conclude by discussing how the strategy of using wild type strains to represent nature in the lab has nonetheless survived the downfall of the wild type concept and continues to provide, significant limitations acknowledged, an epistemically productive means of investigating heredity and evolutionary variation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Immunity status of adults and children against poliomyelitis virus type 1 strains CHAT and Sabin (LSc-2ab in Germany

    Directory of Open Access Journals (Sweden)

    Diedrich Sabine

    2010-12-01

    Full Text Available Abstract Background In October 2007, the working group CEN/TC 216 of the European Committee for standardisation suggested that the Sabin oral poliovirus vaccine type 1 strain (LSc-2ab presently used for virucidal tests should be replaced by another attenuated vaccine poliovirus type 1 strain, CHAT. Both strains were historically used as oral vaccines, but the Sabin type 1 strain was acknowledged to be more attenuated. In Germany, vaccination against poliomyelitis was introduced in 1962 using the oral polio vaccine (OPV containing Sabin strain LSc-2ab. The vaccination schedule was changed from OPV to an inactivated polio vaccine (IPV containing wild polio virus type 1 strain Mahoney in 1998. In the present study, we assessed potential differences in neutralising antibody titres to Sabin and CHAT in persons with a history of either OPV, IPV, or OPV with IPV booster. Methods Neutralisation poliovirus antibodies against CHAT and Sabin 1 were measured in sera of 41 adults vaccinated with OPV. Additionally, sera from 28 children less than 10 years of age and immunised with IPV only were analysed. The neutralisation assay against poliovirus was performed according to WHO guidelines. Results The neutralisation activity against CHAT in adults with OPV vaccination history was significantly lower than against Sabin poliovirus type 1 strains (Wilcoxon signed-rank test P Conclusion The lack of neutralising antibodies against the CHAT strain in persons vaccinated with OPV might be associated with an increased risk of reinfection with the CHAT polio virus type 1, and this implies a putative risk of transmission of the virus to polio-free communities. We strongly suggest that laboratory workers who were immunised with OPV receive a booster vaccination with IPV before handling CHAT in the laboratory.

  20. Genetic and phenotypic diversity of naturally isolated wild strains of Aspergillus niger with hyper glucose oxidase production

    Directory of Open Access Journals (Sweden)

    MAHMOUD EL-HARIRI

    2015-12-01

    Full Text Available Glucose oxidase (GOx is the basic stone for many of biological industry worldwide. The improvement of GOx production basically depends on selection of hyper producer strain of Aspergillus niger. Selective isolation and screening for natural hyper producer strains of A. niger and sequence analysis of the GOD gene, which is responsible for production of the enzyme, are very effective approaches to investigate the naturally modified strains of A. niger with hyper productive capacity of GOx enzyme. The aims of the current study were selective isolation of naturally hyper GOx producing strains of A. niger and evaluation of their GOx activities under optimized parameters in the laboratory. Five wild Egyptian isolates of A. niger were screened for GOx and catalase activity using two types of modified basal liquid media. The GOx activity was evaluated by high throughout liquid phase system. The isolates showed a variable activity for GOx production ranged from 0 to 28.7 U.ml-1. One isolate coded Strain 7 was negative GOx producer on Vogel's broth medium in comparison to other isolates, while its GOx activity on Cazpek Dox was considered as positive (7.28 U.ml-1. It was concluded that GOx production is affected by three controllable factors – the basal media components, time of incubation, and the strain with its adaption to the media components‎. Also, the catalase activity was tested and it was produced with a different degree of variability, which may be reflected on GOx stability. GOD genes of these wild variant of A. niger were cloned and sequenced to determine intraspecies diversity of GOD between the wild variants. The comparison of isolated wild variants to other reference hyper GOx producer strains of A. niger was performed to determine if the GOD sequence analysis of these strains can be distinguished based on their GOx activity. This is the first report for isolation and detection of naturally A. niger hyper GOx-producer strains with

  1. Divergence in wine characteristics produced by wild and domesticated strains of Saccharomyces cerevisiae

    Science.gov (United States)

    Hyma, Katie E; Saerens, Sofie M; Verstrepen, Kevin J; Fay, Justin C

    2011-01-01

    The budding yeast Saccharomyces cerevisiae is the primary species used by wine makers to convert sugar into alcohol during wine fermentation. Saccharomyces cerevisiae is found in vineyards, but is also found in association with oak trees and other natural sources. Although wild strains of S. cerevisiae as well as other Saccharomyces species are also capable of wine fermentation, a genetically distinct group of S. cerevisiae strains is primarily used to produce wine, consistent with the idea that wine making strains have been domesticated for wine production. In this study, we demonstrate that humans can distinguish between wines produced using wine strains and wild strains of S. cerevisiae as well as its sibling species, Saccharomyces paradoxus. Wine strains produced wine with fruity and floral characteristics, whereas wild strains produced wine with earthy and sulfurous characteristics. The differences that we observe between wine and wild strains provides further evidence that wine strains have evolved phenotypes that are distinct from their wild ancestors and relevant to their use in wine production. PMID:22093681

  2. Molecular Evolution of a Type 1 Wild-Vaccine Poliovirus Recombinant during Widespread Circulation in China

    Science.gov (United States)

    Liu, Hong-Mei; Zheng, Du-Ping; Zhang, Li-Bi; Oberste, M. Steven; Pallansch, Mark A.; Kew, Olen M.

    2000-01-01

    Type 1 wild-vaccine recombinant polioviruses were isolated from poliomyelitis patients in China from 1991 to 1993. We compared the sequences of 34 recombinant isolates over the 1,353-nucleotide (nt) genomic interval (nt 2480 to 3832) encoding the major capsid protein, VP1, and the protease, 2A. All recombinants had a 367-nt block of sequence (nt 3271 to 3637) derived from the Sabin 1 oral poliovirus vaccine strain spanning the 3′-terminal sequences of VP1 (115 nt) and the 5′ half of 2A (252 nt). The remaining VP1 sequences were closely (up to 99.5%) related to those of a major genotype of wild type 1 poliovirus endemic to China up to 1994. In contrast, the non-vaccine-derived sequences at the 3′ half of 2A were more distantly related (polioviruses from China. The vaccine-derived sequences of the earliest (April 1991) isolates completely matched those of Sabin 1. Later isolates diverged from the early isolates primarily by accumulation of synonymous base substitutions (at a rate of ∼3.7 × 10−2 substitutions per synonymous site per year) over the entire VP1-2A interval. Distinct evolutionary lineages were found in different Chinese provinces. From the combined epidemiologic and evolutionary analyses, we propose that the recombinant virus arose during mixed infection of a single individual in northern China in early 1991 and that its progeny spread by multiple independent chains of transmission into some of the most populous areas of China within a year of the initiating infection. PMID:11070012

  3. Characterization of global yeast quantitative proteome data generated from the wild-type and glucose repression Saccharomyces cerevisiae strains: The comparison of two quantitative methods

    DEFF Research Database (Denmark)

    Usaite, Renata; Wohlschlegel, James; Venable, John D.

    2008-01-01

    The quantitative proteomic analysis of complex protein mixtures is emerging as a technically challenging but viable systems-level approach for studying cellular function. This study presents a large-scale comparative analysis of protein abundances from yeast protein lysates derived from both wild......-type yeast and yeast strains lacking key components of the Snf1 kinase complex. Four different strains were grown under well-controlled chemostat conditions. Multidimensional protein identification technology followed by quantitation using either spectral counting or stable isotope labeling approaches...... labeling strategy. The stable isotope labeling based quantitative approach was found to be highly reproducible among biological replicates when complex protein mixtures containing small expression changes were analyzed. Where poor correlation between stable isotope labeling and spectral counting was found...

  4. Immunity status of adults and children against poliomyelitis virus type 1 strains CHAT and Sabin (LSc-2ab) in Germany.

    Science.gov (United States)

    Eggers, Maren; Terletskaia-Ladwig, Elena; Rabenau, Holger F; Doerr, Hans W; Diedrich, Sabine; Enders, Gisela; Enders, Martin

    2010-12-09

    In October 2007, the working group CEN/TC 216 of the European Committee for standardisation suggested that the Sabin oral poliovirus vaccine type 1 strain (LSc-2ab) presently used for virucidal tests should be replaced by another attenuated vaccine poliovirus type 1 strain, CHAT. Both strains were historically used as oral vaccines, but the Sabin type 1 strain was acknowledged to be more attenuated. In Germany, vaccination against poliomyelitis was introduced in 1962 using the oral polio vaccine (OPV) containing Sabin strain LSc-2ab. The vaccination schedule was changed from OPV to an inactivated polio vaccine (IPV) containing wild polio virus type 1 strain Mahoney in 1998. In the present study, we assessed potential differences in neutralising antibody titres to Sabin and CHAT in persons with a history of either OPV, IPV, or OPV with IPV booster. Neutralisation poliovirus antibodies against CHAT and Sabin 1 were measured in sera of 41 adults vaccinated with OPV. Additionally, sera from 28 children less than 10 years of age and immunised with IPV only were analysed. The neutralisation assay against poliovirus was performed according to WHO guidelines. The neutralisation activity against CHAT in adults with OPV vaccination history was significantly lower than against Sabin poliovirus type 1 strains (Wilcoxon signed-rank test P Sabin 1 varied between 8 and 64. Following IPV booster, anti-CHAT antibodies increased rapidly in sera of CHAT-negative adults with OPV history. Sera from children with IPV history neutralised CHAT and Sabin 1 strains equally. The lack of neutralising antibodies against the CHAT strain in persons vaccinated with OPV might be associated with an increased risk of reinfection with the CHAT polio virus type 1, and this implies a putative risk of transmission of the virus to polio-free communities. We strongly suggest that laboratory workers who were immunised with OPV receive a booster vaccination with IPV before handling CHAT in the laboratory.

  5. Clavulanic acid production by the MMS 150 mutant obtained from wild type Streptomyces clavuligerus ATCC 27064

    Directory of Open Access Journals (Sweden)

    Eliton da Silva Vasconcelos

    2013-12-01

    Full Text Available Clavulanic acid (CA is a powerful inhibitor of the beta-lactamases, enzymes produced by bacteria resistants to penicillin and cefalosporin. This molecule is produced industrially by strains of Streptomyces clavuligerus in complex media which carbon and nitrogen resources are supplied by inexpensive compounds still providing high productivity. The genetic production improvement using physical and chemical mutagenic agents is an important strategy in programs of industrial production development of bioactive metabolites. However, parental strains are susceptible to loss of their original productivity due genetic instability phenomenona. In this work, some S. clavuligerus mutant strains obtained by treatment with UV light and with MMS are compared with the wild type (Streptomyces clavuligerus ATCC 27064. The results indicated that the random mutations originated some strains with different phenotypes, most divergent demonstrated by the mutants strains named AC116, MMS 150 and MMS 54, that exhibited lack of pigmentation in their mature spores. Also, the strain MMS 150 presented a larger production of CA when cultivated in semi-synthetics media. Using other media, the wild type strain obtained a larger CA production. Besides, using the modifed complex media the MMS 150 strain showed changes in its lipolitic activity and a larger production of CA. The studies also allowed finding the best conditions for a lipase activity exhibited by wild type S. clavuligerus and the MMS150 mutant.

  6. Clavulanic acid production by the MMS 150 mutant obtained from wild type Streptomyces clavuligerus ATCC 27064.

    Science.gov (United States)

    da Silva Vasconcelos, Eliton; de Lima, Vanderlei Aparecido; Goto, Leandro Seiji; Cruz-Hernández, Isara Lourdes; Hokka, Carlos Osamu

    2013-12-01

    Clavulanic acid (CA) is a powerful inhibitor of the beta-lactamases, enzymes produced by bacteria resistants to penicillin and cefalosporin. This molecule is produced industrially by strains of Streptomyces clavuligerus in complex media which carbon and nitrogen resources are supplied by inexpensive compounds still providing high productivity. The genetic production improvement using physical and chemical mutagenic agents is an important strategy in programs of industrial production development of bioactive metabolites. However, parental strains are susceptible to loss of their original productivity due genetic instability phenomenona. In this work, some S. clavuligerus mutant strains obtained by treatment with UV light and with MMS are compared with the wild type (Streptomyces clavuligerus ATCC 27064). The results indicated that the random mutations originated some strains with different phenotypes, most divergent demonstrated by the mutants strains named AC116, MMS 150 and MMS 54, that exhibited lack of pigmentation in their mature spores. Also, the strain MMS 150 presented a larger production of CA when cultivated in semi-synthetics media. Using other media, the wild type strain obtained a larger CA production. Besides, using the modifed complex media the MMS 150 strain showed changes in its lipolitic activity and a larger production of CA. The studies also allowed finding the best conditions for a lipase activity exhibited by wild type S. clavuligerus and the MMS150 mutant.

  7. ITS1/5.8S/ITS2, a Good Marker for Initial Classification of Shiitake Culinary-Medicinal Lentinus edodes (Agaricomycetes) Strains in China.

    Science.gov (United States)

    Song, Xiao-Xia; Zhao, Yan; Song, Chun-Yan; Li, Chuan-Hua; Song, Ying; Chen, Ming-Jie; Bao, Da-Peng; Tan, Qi

    2018-01-01

    China is home to rich wild and cultivated strains of Lentinus edodes, an important edible and medicinal mushroom. Artificial selection of L. edodes has a long history, and the widely cultivated strains belong to populations different from those of most wild strains. Internal transcribed spacer (ITS) regions have been used as good markers to identify L. edodes populations. But because ITS regions exhibit incomplete concerted evolution, the use of an ITS to identify L. edodes populations has been questioned. The objective of this study was to determine whether the ITS region is suitable for identifying L. edodes populations and which populations the widely cultivated strains and the most wild strains belong to by investigating intraindividual and differential ITS polymorphisms between 44 cultivars and 44 wild strains of L. edodes in China. Intraindividual ITS polymorphism is common in L. edodes strains, and most strains possessed 2 different ITS sequences, which came from their heterokaryons. The genetic polymorphisms of ITS1, 5.8S, and ITS2 in L. edodes strains are distinct. All strains were divided into one 5.8S type (5.8S-A), 2 ITS1 types (ITS1-A and ITS1-B), and 2 ITS2 types (ITS2-A and ITS2-B), which were subdivided into 2 branches (ITS2-A1 and ITS2-A2; ITS2-B1 and ITS2-B2). ITS1/5.8S/ITS2 could be used as a good marker in preliminary classification of L. edodes strains in China. It not only exhibited classified information of ITS1, 5.8S, and ITS2 for each strain at the same time, it also indicated whether the strain was heterozygous. The 44 cultivated strains were mainly the A/A/A1 type, and the 44 wild strains were mainly the A/A/A2 and other mixed types.

  8. Mineral characterisation of Don Pao rare earth deposit in Vietnam

    International Nuclear Information System (INIS)

    XuanBen, T.

    1998-01-01

    Full text: The Don Pao Rare Earth Deposit was discovered in 1959 in Phon Tho district, about 450km North-West of Hanoi capital. Geological work was conducted between 1959-95, resulting in 60 ore bodies of various sizes being identified. The ore bodies are irregularly shaped nests, lenses and veins hosted in the shear zone, at the margin of a Paeleogene aged syenite massif. The mineral composition of Don Pao Deposit is very complex, consisting of more than 50 minerals. Among them, basnaesite, parisite, fluorite and barite are the main constituent minerals of the ore. All the minerals were identified by the modern methods of mineralogical studies. Based on the constituent mineral ratios, four ore types have been distinguished in the deposit: 1. Rare earth ore containing over 5 percent of RE 2 O 3 . 2. Rare Earth-Barite ore containing 0.5 to 30 percent of RE 2 O 3 . 3. Rare Earth-Barite-Fluorite ore containing 1 to 5 percent of RE 2 O 3 . 4. Rare Earth bearing Fluorite ore containing 1 to 5 percent of RE 2 O 3 . According to the benefication test, the ores in Don Pao can be enriched to a concentrate of 60 percent of RE 2 O 3 with a recover of 75 percent

  9. The fusion protein of wild-type canine distemper virus is a major determinant of persistent infection

    International Nuclear Information System (INIS)

    Plattet, Philippe; Rivals, Jean-Paul; Zuber, BenoIt; Brunner, Jean-Marc; Zurbriggen, Andreas; Wittek, Riccardo

    2005-01-01

    The wild-type A75/17 canine distemper virus (CDV) strain induces a persistent infection in the central nervous system but infects cell lines very inefficiently. In contrast, the genetically more distant Onderstepoort CDV vaccine strain (OP-CDV) induces extensive syncytia formation. Here, we investigated the roles of wild-type fusion (F WT ) and attachment (H WT ) proteins in Vero cells expressing, or not, the canine SLAM receptor by transfection experiments and by studying recombinants viruses expressing different combinations of wild-type and OP-CDV glycoproteins. We show that low fusogenicity is not due to a defect of the envelope proteins to reach the cell surface and that H WT determines persistent infection in a receptor-dependent manner, emphasizing the role of SLAM as a potent enhancer of fusogenicity. However, importantly, F WT reduced cell-to-cell fusion independently of the cell surface receptor, thus demonstrating that the fusion protein of the neurovirulent A75/17-CDV strain plays a key role in determining persistent infection

  10. Pharmacologic Treatment Assigned for Niemann Pick Type C1 Disease Partly Changes Behavioral Traits in Wild-Type Mice.

    Science.gov (United States)

    Schlegel, Victoria; Thieme, Markus; Holzmann, Carsten; Witt, Martin; Grittner, Ulrike; Rolfs, Arndt; Wree, Andreas

    2016-11-09

    Niemann-Pick Type C1 (NPC1) is an autosomal recessive inherited disorder characterized by accumulation of cholesterol and glycosphingolipids. Previously, we demonstrated that BALB/c-npc1 nih Npc1 -/- mice treated with miglustat, cyclodextrin and allopregnanolone generally performed better than untreated Npc1 -/- animals. Unexpectedly, they also seemed to accomplish motor tests better than their sham-treated wild-type littermates. However, combination-treated mutant mice displayed worse cognition performance compared to sham-treated ones. To evaluate effects of these drugs in healthy BALB/c mice, we here analyzed pharmacologic effects on motor and cognitive behavior of wild-type mice. For combination treatment mice were injected with allopregnanolone/cyclodextrin weekly, starting at P7. Miglustat injections were performed daily from P10 till P23. Starting at P23, miglustat was embedded in the chow. Other mice were treated with miglustat only, or sham-treated. The battery of behavioral tests consisted of accelerod, Morris water maze, elevated plus maze, open field and hot-plate tests. Motor capabilities and spontaneous motor behavior were unaltered in both drug-treated groups. Miglustat-treated wild-type mice displayed impaired spatial learning compared to sham- and combination-treated mice. Both combination- and miglustat-treated mice showed enhanced anxiety in the elevated plus maze compared to sham-treated mice. Additionally, combination treatment as well as miglustat alone significantly reduced brain weight, whereas only combination treatment reduced body weight significantly. Our results suggest that allopregnanolone/cyclodextrin ameliorate most side effects of miglustat in wild-type mice.

  11. Pharmacologic Treatment Assigned for Niemann Pick Type C1 Disease Partly Changes Behavioral Traits in Wild-Type Mice

    Directory of Open Access Journals (Sweden)

    Victoria Schlegel

    2016-11-01

    Full Text Available Niemann-Pick Type C1 (NPC1 is an autosomal recessive inherited disorder characterized by accumulation of cholesterol and glycosphingolipids. Previously, we demonstrated that BALB/c-npc1nihNpc1−/− mice treated with miglustat, cyclodextrin and allopregnanolone generally performed better than untreated Npc1−/− animals. Unexpectedly, they also seemed to accomplish motor tests better than their sham-treated wild-type littermates. However, combination-treated mutant mice displayed worse cognition performance compared to sham-treated ones. To evaluate effects of these drugs in healthy BALB/c mice, we here analyzed pharmacologic effects on motor and cognitive behavior of wild-type mice. For combination treatment mice were injected with allopregnanolone/cyclodextrin weekly, starting at P7. Miglustat injections were performed daily from P10 till P23. Starting at P23, miglustat was embedded in the chow. Other mice were treated with miglustat only, or sham-treated. The battery of behavioral tests consisted of accelerod, Morris water maze, elevated plus maze, open field and hot-plate tests. Motor capabilities and spontaneous motor behavior were unaltered in both drug-treated groups. Miglustat-treated wild-type mice displayed impaired spatial learning compared to sham- and combination-treated mice. Both combination- and miglustat-treated mice showed enhanced anxiety in the elevated plus maze compared to sham-treated mice. Additionally, combination treatment as well as miglustat alone significantly reduced brain weight, whereas only combination treatment reduced body weight significantly. Our results suggest that allopregnanolone/cyclodextrin ameliorate most side effects of miglustat in wild-type mice.

  12. An emerging role for misfolded wild-type SOD1 in sporadic ALS pathogenesis

    Directory of Open Access Journals (Sweden)

    Melissa S Rotunno

    2013-12-01

    Full Text Available Amyotrophic lateral sclerosis (ALS is a fatal neurodegenerative disorder that targets motor neurons, leading to paralysis and death within a few years of disease onset. While several genes have been linked to the inheritable, or familial, form of ALS, much less is known about the cause(s of sporadic ALS, which accounts for approximately 90% of ALS cases. Due to the clinical similarities between familial and sporadic ALS, it is plausible that both forms of the disease converge on a common pathway and, therefore, involve common factors. Recent evidence suggests the Cu,Zn-superoxide dismutase (SOD1 protein to be one such factor that is common to both sporadic and familial ALS. In 1993, mutations were uncovered in SOD1 that represent the first known genetic cause of familial ALS. While the exact mechanism of mutant-SOD1 toxicity is still not known today, most evidence points to a gain of toxic function that stems, at least in part, from the propensity of this protein to misfold. In the wild-type SOD1 protein, non-genetic perturbations such as metal depletion, disruption of the quaternary structure, and oxidation, can also induce SOD1 to misfold. In fact, these aforementioned post-translational modifications cause wild-type SOD1 to adopt a toxic conformation that is similar to familial ALS-linked SOD1 variants. These observations, together with the detection of misfolded wild-type SOD1 within human post-mortem sporadic ALS samples, have been used to support the controversial hypothesis that misfolded forms of wild-type SOD1 contribute to sporadic ALS pathogenesis. In this review, we present data from the literature that both support and contradict this hypothesis. We also discuss SOD1 as a potential therapeutic target for both familial and sporadic ALS.

  13. Microalgal sensitivity varies between a diuron-resistant strain and two wild strains when exposed to diuron and irgarol, alone and in mixtures.

    Science.gov (United States)

    Dupraz, Valentin; Coquillé, Nathalie; Ménard, Dominique; Sussarellu, Rossana; Haugarreau, Larissa; Stachowski-Haberkorn, Sabine

    2016-05-01

    A wild strain of Chaetoceros calcitrans and wild and diuron-resistant strains of Tetraselmis suecica, were exposed to the PSII inhibitor herbicides diuron and irgarol, individually and in mixtures. The effects of three concentrations of diuron and irgarol and four binary mixtures were evaluated on doubling time, relative reactive oxygen species and lipid content by flow cytometry, and on photosynthetic efficiency by pulse amplitude modulated fluorescence. In both wild strains, significant effects were observed for each molecule at the highest concentration tested: at irgarol 0.5 μg L(-1), C. calcitrans was shown to be more sensitive than T. suecica (+52% and +19% in doubling time, respectively), whereas at diuron 5 μg L(-1), T. suecica was more affected (+125% in doubling time) than C. calcitrans (+21%). Overall, irgarol had a higher toxicity at a lower concentration than diuron (no effect at diuron 0.5 μg L(-1)) for both wild strains. The strongest mixture (irgarol 0.5 μg L(-1) + diuron 5 μg L(-1)) increased doubling time by 356% for T. suecica, thus showing amplified effects when the two compounds were mixed. Sequencing of the diuron-resistant strain demonstrated a single mutation in the psbA gene coding sequence. Although resistance of this strain to diuron was confirmed with no effect at the highest diuron concentration, no resistance to irgarol was shown. In addition, the mutant strain exposed to the strongest mixture showed a 3.5-fold increase in doubling time compared with irgarol alone, thereby supporting the hypothesis of a biochemical interaction between these two compounds. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Brucella abortus ΔrpoE1 confers protective immunity against wild type challenge in a mouse model of brucellosis.

    Science.gov (United States)

    Willett, Jonathan W; Herrou, Julien; Czyz, Daniel M; Cheng, Jason X; Crosson, Sean

    2016-09-30

    The Brucella abortus general stress response (GSR) system regulates activity of the alternative sigma factor, σ(E1), which controls transcription of approximately 100 genes and is required for persistence in a BALB/c mouse chronic infection model. We evaluated the host response to infection by a B. abortus strain lacking σ(E1) (ΔrpoE1), and identified pathological and immunological features that distinguish ΔrpoE1-infected mice from wild-type (WT), and that correspond with clearance of ΔrpoE1 from the host. ΔrpoE1 infection was indistinguishable from WT in terms of splenic bacterial burden, inflammation and histopathology up to 6weeks post-infection. However, Brucella-specific serum IgG levels in ΔrpoE1-infected mice were 5 times higher than WT by 4weeks post-infection, and remained significantly higher throughout the course of a 12-week infection. Total IgG and Brucella-specific IgG levels peaked strongly in ΔrpoE1-infected mice at 6weeks, which correlated with reduced splenomegaly and bacterial burden relative to WT-infected mice. Given the difference in immune response to infection with wild-type and ΔrpoE1, we tested whether ΔrpoE1 confers protective immunity to wild-type challenge. Mice immunized with ΔrpoE1 completely resisted WT infection and had significantly higher serum titers of Brucella-specific IgG, IgG2a and IFN-γ after WT challenge relative to age-matched naïve mice. We conclude that immunization of BALB/c mice with the B. abortus GSR pathway mutant, ΔrpoE1, elicits an adaptive immune response that confers significant protective immunity against WT infection. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. [Production of monoclonal antibodies against a wild strain of rabies virus].

    Science.gov (United States)

    Akacem, O; Benmansour, A; Coulon, P; Brahimi, M; Benhassine, M

    1992-01-01

    Production of monoclonal antibodies against a wild strain of rabies virus. Cell fusion of SP 2/O, a murine myeloma against a wild strain of rabies virus has originated five monoclonal antibodies (M.A.) specific for virus nucleocapsid , one M.A. specific for virus glycoprotein and one M.A. specific for a viral membrane protein.

  16. The first pathogenic Yersinia enterocolitica bioserotype 4/O:3 strain isolated from a hunted wild boar (Sus scrofa) in Poland.

    Science.gov (United States)

    Bancerz-Kisiel, A; Platt-Samoraj, A; Szczerba-Turek, A; Syczyło, K; Szweda, W

    2015-10-01

    The objective of this study was to identify the bioserotypes and virulence markers of Yersinia enterocolitica strains isolated from wild boars in Poland. Bacteriological examination of 302 rectal swabs from 151 wild boars resulted in the isolation of 40 Y. enterocolitica strains. The majority of the examined strains (n = 30), belonged to bioserotype 1A/NI. The presence of individual Y. enterocolitica strains belonging to bioserotypes 1B/NI (3), 1A/O:8 (2), 1A/O:27 (2), 2/NI (1), 2/O:9 (1) and 4/O:3 (1) was also demonstrated. Amplicons corresponding to ail and ystA genes were observed only in one Y. enterocolitica strain--bioserotype 4/O:3. The ail and ystB gene amplicons were noted in 11 Y. enterocolitica biotype 1A strains, although single amplicons of ystB gene were found in 28 of the tested samples. In four out of eight cases when two Y. enterocolitica strains were isolated from the same animal, the strains differed in biotype, serotype or virulence markers. The European population of wild boars continues to grow and spread to new areas, therefore, wild boars harbouring potentially pathogenic Y. enterocolitica 4/O:3 strains pose a challenge to public health.

  17. A duck hepatitis B virus strain with a knockout mutation in the putative X ORF shows similar infectivity and in vivo growth characteristics to wild-type virus

    International Nuclear Information System (INIS)

    Meier, P.; Scougall, C.A.; Will, H.; Burrell, C.J.; Jilbert, A.R.

    2003-01-01

    Hepadnaviruses including human hepatitis B virus (HBV) and duck hepatitis B virus (DHBV) express X proteins, HBx and DHBx, respectively. Both HBx and DHBx are transcriptional activators and modulate cellular signaling in in vitro assays. To test whether the DHBx protein plays a role in virus infection, we compared the in vivo infectivity and growth characteristics of a DHBV3 strain with a stop codon in the X-like ORF (DHBV3-X-K.O.) to those of the wild-type DHBV3 strain. Here we report that the two strains showed no significant difference in (i) their ability to induce infection that resulted in stable viraemia measured by serum surface antigen (DHBsAg) and DHBV DNA, and detection of viral proteins and replicative DNA intermediates in the liver; (ii) the rate of spread of infection in liver and extrahepatic sites after low-dose virus inoculation; and (iii) the ability to produce transient or persistent infection under balanced age/dose conditions designed to detect small differences between the strains. Thus, none of the infection parameters assayed were detectably affected by the X-ORF knockout mutation, raising the question whether DHBx expression plays a physiological role during in vivo infection with wild-type DHBV

  18. Sequence analysis of chromosome 1 revealed different selection patterns between Chinese wild mice and laboratory strains.

    Science.gov (United States)

    Xu, Fuyi; Hu, Shixian; Chao, Tianzhu; Wang, Maochun; Li, Kai; Zhou, Yuxun; Xu, Hongyan; Xiao, Junhua

    2017-10-01

    Both natural and artificial selection play a critical role in animals' adaptation to the environment. Detection of the signature of selection in genomic regions can provide insights for understanding the function of specific phenotypes. It is generally assumed that laboratory mice may experience intense artificial selection while wild mice more natural selection. However, the differences of selection signature in the mouse genome and underlying genes between wild and laboratory mice remain unclear. In this study, we used two mouse populations: chromosome 1 (Chr 1) substitution lines (C1SLs) derived from Chinese wild mice and mouse genome project (MGP) sequenced inbred strains and two selection detection statistics: Fst and Tajima's D to identify the signature of selection footprint on Chr 1. For the differentiation between the C1SLs and MGP, 110 candidate selection regions containing 47 protein coding genes were detected. A total of 149 selection regions which encompass 7.215 Mb were identified in the C1SLs by Tajima's D approach. While for the MGP, we identified nearly twice selection regions (243) compared with the C1SLs which accounted for 13.27 Mb Chr 1 sequence. Through functional annotation, we identified several biological processes with significant enrichment including seven genes in the olfactory transduction pathway. In addition, we searched the phenotypes associated with the 47 candidate selection genes identified by Fst. These genes were involved in behavior, growth or body weight, mortality or aging, and immune systems which align well with the phenotypic differences between wild and laboratory mice. Therefore, the findings would be helpful for our understanding of the phenotypic differences between wild and laboratory mice and applications for using this new mouse resource (C1SLs) for further genetics studies.

  19. Detection of multiple cocirculating wild poliovirus type 1 lineages through environmental surveillance: impact and progress during 2011-2013 in Pakistan.

    Science.gov (United States)

    Alam, Muhammad Masroor; Shaukat, Shahzad; Sharif, Salmaan; Angez, Mehar; Khurshid, Adnan; Malik, Farzana; Rehman, Lubna; Zaidi, Syed Sohail Zahoor

    2014-11-01

    The environmental surveillance has proven to be a useful tool to identify poliovirus circulation in different countries and was started in Pakistan during July 2009 to support the acute flaccid paralysis (AFP) surveillance system. Sewage samples were collected from 27 environmental sampling (ENV) sites and processed for poliovirus isolation through 2-phase separation method. Poliovirus isolates were identified as Sabin-like or wild type through real-time polymerase chain reaction (PCR). Wild-type strains were subjected to VP1 gene sequencing and phylogenetic analysis performed using MEGA 5.0. During 2011-2013, a total of 668 samples were collected from 4 provinces that resulted in 40% of samples positive for wild poliovirus type-1 (WPV-1). None of the samples were positive for WPV-3. The areas with high frequency of WPV-1 detection were Karachi-Gadap (69%), Peshawar (82%), and Rawalpindi (65%), whereas the samples from Quetta and Sukkur remained negative for WPV during 2013. Phylogenetic analysis revealed 3 major clusters with multiple poliovirus lineages circulating across different country areas as well as in bordering areas of Afghanistan. Environmental surveillance in Pakistan has been proven to be a powerful tool to detect WPV circulation in the absence of poliomyelitis cases in many communities. Our findings emphasize the need to continue and expand such surveillance activities to other high-risk areas in the country. © The Author 2014. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  20. Heteromeric p97/p97R155C complexes induce dominant negative changes in wild-type and autophagy 9-deficient Dictyostelium strains.

    Directory of Open Access Journals (Sweden)

    Khalid Arhzaouy

    Full Text Available Heterozygous mutations in the human VCP (p97 gene cause autosomal-dominant IBMPFD (inclusion body myopathy with early onset Paget's disease of bone and frontotemporal dementia, ALS14 (amyotrophic lateral sclerosis with or without frontotemporal dementia and HSP (hereditary spastic paraplegia. Most prevalent is the R155C point mutation. We studied the function of p97 in the social amoeba Dictyostelium discoideum and have generated strains that ectopically express wild-type (p97 or mutant p97 (p97(R155C fused to RFP in AX2 wild-type and autophagy 9 knock-out (ATG9(KO cells. Native gel electrophoresis showed that both p97 and p97(R155C assemble into hexamers. Co-immunoprecipitation studies revealed that endogenous p97 and p97(R155C-RFP form heteromers. The mutant strains displayed changes in cell growth, phototaxis, development, proteasomal activity, ubiquitinylated proteins, and ATG8(LC3 indicating mis-regulation of multiple essential cellular processes. Additionally, immunofluorescence analysis revealed an increase of protein aggregates in ATG9(KO/p97(R155C-RFP and ATG9(KO cells. They were positive for ubiquitin in both strains, however, solely immunoreactive for p97 in the ATG9(KO mutant. A major finding is that the expression of p97(R155C-RFP in the ATG9(KO strain partially or fully rescued the pleiotropic phenotype. We also observed dose-dependent effects of p97 on several cellular processes. Based on findings in the single versus the double mutants we propose a novel mode of p97 interaction with the core autophagy protein ATG9 which is based on mutual inhibition.

  1. The Antiproliferative Effect of Cyclodipeptides from Pseudomonas aeruginosa PAO1 on HeLa Cells Involves Inhibition of Phosphorylation of Akt and S6k Kinases.

    Science.gov (United States)

    Hernández-Padilla, Laura; Vázquez-Rivera, Dolores; Sánchez-Briones, Luis A; Díaz-Pérez, Alma L; Moreno-Rodríguez, José; Moreno-Eutimio, Mario A; Meza-Carmen, Victor; Cruz, Homero Reyes-De la; Campos-García, Jesús

    2017-06-20

    Pseudomonas aeruginosa PAO1, a potential pathogen of plants and animals, produces the cyclodipeptides cyclo(l-Pro-l-Tyr), cyclo(l-Pro-l-Phe), and cyclo(l-Pro-l-Val) (PAO1-CDPs), whose effects have been implicated in inhibition of human tumor cell line proliferation. Our purpose was to investigate in depth in the mechanisms of HeLa cell proliferation inhibition by the PAO1-CDPs. The results indicate that PAO1-CDPs, both purified individually and in mixtures, inhibited HeLa cell proliferation by arresting the cell cycle at the G0-G1 transition. The crude PAO1-CDPs mixture promoted cell death in HeLa cells in a dose-dependent manner, showing efficacy similar to that of isolated PAO1-CDPs (LD 50 of 60-250 µM) and inducing apoptosis with EC 50 between 0.6 and 3.0 µM. Moreover, PAO1-CDPs showed a higher proapoptotic activity (~10³-10⁵ fold) than their synthetic analogs did. Subsequently, the PAO1-CDPs affected mitochondrial membrane potential and induced apoptosis by caspase-9-dependent pathway. The mechanism of inhibition of cells proliferation in HeLa cells involves inhibition of phosphorylation of both Akt-S473 and S6k-T389 protein kinases, showing a cyclic behavior of their expression and phosphorylation in a time and concentration-dependent fashion. Taken together our findings indicate that PI3K-Akt-mTOR-S6k signaling pathway blockage is involved in the antiproliferative effect of the PAO1-CDPs.

  2. Wild-type and mutated IDH1/2 enzymes and therapy responses.

    Science.gov (United States)

    Molenaar, Remco J; Maciejewski, Jaroslaw P; Wilmink, Johanna W; van Noorden, Cornelis J F

    2018-04-01

    Isocitrate dehydrogenase 1 and 2 (IDH1/2) are key enzymes in cellular metabolism, epigenetic regulation, redox states, and DNA repair. IDH1/2 mutations are causal in the development and/or progression of various types of cancer due to supraphysiological production of D-2-hydroxyglutarate. In various tumor types, IDH1/2-mutated cancers predict for improved responses to treatment with irradiation or chemotherapy. The present review discusses the molecular basis of the sensitivity of IDH1/2-mutated cancers with respect to the function of mutated IDH1/2 in cellular processes and their interactions with novel IDH1/2-mutant inhibitors. Finally, lessons learned from IDH1/2 mutations for future clinical applications in IDH1/2 wild-type cancers are discussed.

  3. Comparative effects of chlorpyrifos in wild type and cannabinoid Cb1 receptor knockout mice

    Energy Technology Data Exchange (ETDEWEB)

    Baireddy, Praveena; Liu, Jing; Hinsdale, Myron; Pope, Carey, E-mail: carey.pope@okstate.edu

    2011-11-15

    Endocannabinoids (eCBs) modulate neurotransmission by inhibiting the release of a variety of neurotransmitters. The cannabinoid receptor agonist WIN 55.212-2 (WIN) can modulate organophosphorus (OP) anticholinesterase toxicity in rats, presumably by inhibiting acetylcholine (ACh) release. Some OP anticholinesterases also inhibit eCB-degrading enzymes. We studied the effects of the OP insecticide chlorpyrifos (CPF) on cholinergic signs of toxicity, cholinesterase activity and ACh release in tissues from wild type (+/+) and cannabinoid CB1 receptor knockout (-/-) mice. Mice of both genotypes (n = 5-6/treatment group) were challenged with CPF (300 mg/kg, 2 ml/kg in peanut oil, sc) and evaluated for functional and neurochemical changes. Both genotypes exhibited similar cholinergic signs and cholinesterase inhibition (82-95% at 48 h after dosing) in cortex, cerebellum and heart. WIN reduced depolarization-induced ACh release in vitro in hippocampal slices from wild type mice, but had no effect in hippocampal slices from knockouts or in striatal slices from either genotype. Chlorpyrifos oxon (CPO, 100 {mu}M) reduced release in hippocampal slices from both genotypes in vitro, but with a greater reduction in tissues from wild types (21% vs 12%). CPO had no significant in vitro effect on ACh release in striatum. CPF reduced ACh release in hippocampus from both genotypes ex vivo, but reduction was again significantly greater in tissues from wild types (52% vs 36%). In striatum, CPF led to a similar reduction (20-23%) in tissues from both genotypes. Thus, while CB1 deletion in mice had little influence on the expression of acute toxicity following CPF, CPF- or CPO-induced changes in ACh release appeared sensitive to modulation by CB1-mediated eCB signaling in a brain-regional manner. -- Highlights: Black-Right-Pointing-Pointer C57Bl/6 mice showed dose-related cholinergic toxicity following subcutaneous chlorpyrifos exposure. Black-Right-Pointing-Pointer Wild type and

  4. Comparative effects of chlorpyrifos in wild type and cannabinoid Cb1 receptor knockout mice

    International Nuclear Information System (INIS)

    Baireddy, Praveena; Liu, Jing; Hinsdale, Myron; Pope, Carey

    2011-01-01

    Endocannabinoids (eCBs) modulate neurotransmission by inhibiting the release of a variety of neurotransmitters. The cannabinoid receptor agonist WIN 55.212-2 (WIN) can modulate organophosphorus (OP) anticholinesterase toxicity in rats, presumably by inhibiting acetylcholine (ACh) release. Some OP anticholinesterases also inhibit eCB-degrading enzymes. We studied the effects of the OP insecticide chlorpyrifos (CPF) on cholinergic signs of toxicity, cholinesterase activity and ACh release in tissues from wild type (+/+) and cannabinoid CB1 receptor knockout (−/−) mice. Mice of both genotypes (n = 5–6/treatment group) were challenged with CPF (300 mg/kg, 2 ml/kg in peanut oil, sc) and evaluated for functional and neurochemical changes. Both genotypes exhibited similar cholinergic signs and cholinesterase inhibition (82–95% at 48 h after dosing) in cortex, cerebellum and heart. WIN reduced depolarization-induced ACh release in vitro in hippocampal slices from wild type mice, but had no effect in hippocampal slices from knockouts or in striatal slices from either genotype. Chlorpyrifos oxon (CPO, 100 μM) reduced release in hippocampal slices from both genotypes in vitro, but with a greater reduction in tissues from wild types (21% vs 12%). CPO had no significant in vitro effect on ACh release in striatum. CPF reduced ACh release in hippocampus from both genotypes ex vivo, but reduction was again significantly greater in tissues from wild types (52% vs 36%). In striatum, CPF led to a similar reduction (20–23%) in tissues from both genotypes. Thus, while CB1 deletion in mice had little influence on the expression of acute toxicity following CPF, CPF- or CPO-induced changes in ACh release appeared sensitive to modulation by CB1-mediated eCB signaling in a brain-regional manner. -- Highlights: ► C57Bl/6 mice showed dose-related cholinergic toxicity following subcutaneous chlorpyrifos exposure. ► Wild type and cannabinoid CB1 receptor knockout littermates

  5. Complete genome sequence of Rhodospirillum rubrum type strain (S1).

    Science.gov (United States)

    Munk, A Christine; Copeland, Alex; Lucas, Susan; Lapidus, Alla; Del Rio, Tijana Glavina; Barry, Kerrie; Detter, John C; Hammon, Nancy; Israni, Sanjay; Pitluck, Sam; Brettin, Thomas; Bruce, David; Han, Cliff; Tapia, Roxanne; Gilna, Paul; Schmutz, Jeremy; Larimer, Frank; Land, Miriam; Kyrpides, Nikos C; Mavromatis, Konstantinos; Richardson, Paul; Rohde, Manfred; Göker, Markus; Klenk, Hans-Peter; Zhang, Yaoping; Roberts, Gary P; Reslewic, Susan; Schwartz, David C

    2011-07-01

    Rhodospirillum rubrum (Esmarch 1887) Molisch 1907 is the type species of the genus Rhodospirillum, which is the type genus of the family Rhodospirillaceae in the class Alphaproteobacteria. The species is of special interest because it is an anoxygenic phototroph that produces extracellular elemental sulfur (instead of oxygen) while harvesting light. It contains one of the most simple photosynthetic systems currently known, lacking light harvesting complex 2. Strain S1(T) can grow on carbon monoxide as sole energy source. With currently over 1,750 PubMed entries, R. rubrum is one of the most intensively studied microbial species, in particular for physiological and genetic studies. Next to R. centenum strain SW, the genome sequence of strain S1(T) is only the second genome of a member of the genus Rhodospirillum to be published, but the first type strain genome from the genus. The 4,352,825 bp long chromosome and 53,732 bp plasmid with a total of 3,850 protein-coding and 83 RNA genes were sequenced as part of the DOE Joint Genome Institute Program DOEM 2002.

  6. Genome-wide analysis of wild-type Epstein-Barr virus genomes derived from healthy individuals of the 1,000 Genomes Project.

    Science.gov (United States)

    Santpere, Gabriel; Darre, Fleur; Blanco, Soledad; Alcami, Antonio; Villoslada, Pablo; Mar Albà, M; Navarro, Arcadi

    2014-04-01

    Most people in the world (∼90%) are infected by the Epstein-Barr virus (EBV), which establishes itself permanently in B cells. Infection by EBV is related to a number of diseases including infectious mononucleosis, multiple sclerosis, and different types of cancer. So far, only seven complete EBV strains have been described, all of them coming from donors presenting EBV-related diseases. To perform a detailed comparative genomic analysis of EBV including, for the first time, EBV strains derived from healthy individuals, we reconstructed EBV sequences infecting lymphoblastoid cell lines (LCLs) from the 1000 Genomes Project. As strain B95-8 was used to transform B cells to obtain LCLs, it is always present, but a specific deletion in its genome sets it apart from natural EBV strains. After studying hundreds of individuals, we determined the presence of natural EBV in at least 10 of them and obtained a set of variants specific to wild-type EBV. By mapping the natural EBV reads into the EBV reference genome (NC007605), we constructed nearly complete wild-type viral genomes from three individuals. Adding them to the five disease-derived EBV genomic sequences available in the literature, we performed an in-depth comparative genomic analysis. We found that latency genes harbor more nucleotide diversity than lytic genes and that six out of nine latency-related genes, as well as other genes involved in viral attachment and entry into host cells, packaging, and the capsid, present the molecular signature of accelerated protein evolution rates, suggesting rapid host-parasite coevolution.

  7. MLH1-deficient Colorectal Carcinoma With Wild-type BRAF and MLH1 Promoter Hypermethylation Harbor KRAS Mutations and Arise From Conventional Adenomas.

    Science.gov (United States)

    Farchoukh, Lama; Kuan, Shih-Fan; Dudley, Beth; Brand, Randall; Nikiforova, Marina; Pai, Reetesh K

    2016-10-01

    Between 10% and 15% of colorectal carcinomas demonstrate sporadic DNA mismatch-repair protein deficiency as a result of MLH1 promoter methylation and are thought to arise from sessile serrated adenomas, termed the serrated neoplasia pathway. Although the presence of the BRAF V600E mutation is indicative of a sporadic cancer, up to 30% to 50% of colorectal carcinomas with MLH1 promoter hypermethylation will lack a BRAF mutation. We report the clinicopathologic and molecular features of MLH1-deficient colorectal carcinoma with wild-type BRAF and MLH1 promoter hypermethylation (referred to as MLH1-hypermethylated BRAF wild-type colorectal carcinoma, n=36) in comparison with MLH1-deficient BRAF-mutated colorectal carcinoma (n=113) and Lynch syndrome-associated colorectal carcinoma (n=36). KRAS mutations were identified in 31% of MLH1-hypermethylated BRAF wild-type colorectal carcinomas compared with 0% of MLH1-deficient BRAF-mutated colorectal carcinomas and 37% of Lynch syndrome-associated colorectal carcinomas. When a precursor polyp was identified, MLH1-hypermethylated BRAF wild-type colorectal carcinomas arose from precursor polyps resembling conventional tubular/tubulovillous adenomas in contrast to MLH1-deficient BRAF-mutated colorectal carcinomas, which arose from precursor sessile serrated adenomas (PMLH1-hypermethylated BRAF wild-type colorectal carcinoma and MLH1-deficient BRAF-mutated colorectal carcinoma had a predilection for the right colon compared with Lynch syndrome-associated colorectal carcinoma (86% vs. 92% vs. 49%, P0.05). In conclusion, our results indicate that MLH1-hypermethylated BRAF wild-type colorectal carcinomas can harbor KRAS mutations and arise from precursor polyps resembling conventional tubular/tubulovillous adenomas.

  8. Differential Activity of the Oral Glucan Synthase Inhibitor SCY-078 against Wild-Type and Echinocandin-Resistant Strains of Candida Species.

    Science.gov (United States)

    Pfaller, Michael A; Messer, Shawn A; Rhomberg, Paul R; Borroto-Esoda, Katyna; Castanheira, Mariana

    2017-08-01

    SCY-078 (formerly MK-3118) is a novel orally active inhibitor of fungal β-(1,3)-glucan synthase (GS). SCY-078 is a derivative of enfumafungin and is structurally distinct from the echinocandin class of antifungal agents. We evaluated the in vitro activity of this compound against wild-type (WT) and echinocandin-resistant isolates containing mutations in the FKS genes of Candida spp. Against 36 Candida spp. FKS mutants tested, 30 (83.3%) were non-WT to 1 or more echinocandins, and only 9 (25.0%) were non-WT (MIC, >WT-upper limit) to SCY-078. Among C. glabrata isolates carrying FKS alterations, 84.0% were non-WT to the echinocandins versus only 24.0% for SCY-078. In contrast to the echinocandin comparators, the activity of SCY-078 was minimally affected by the presence of FKS mutations, suggesting that this agent is useful in the treatment of Candida infections due to echinocandin-resistant strains. Copyright © 2017 American Society for Microbiology.

  9. Glucose and maltose metabolism in MIG1-disrupted and MAL-constitutive strains of Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Klein, Christopher; Olsson, Lisbeth; Rønnow, B

    1997-01-01

    in a mixed glucose-maltose medium revealed that the MAL-constitutive strains were more alleviated than the single MIG1-disrupted transformant. While all transformants exhibited higher maximum specific growth rates (0.24-0.25 h(-1)) in glucose-maltose mixtures than the wild type strain (0.20 h(-1)), the MAL-constitutive...

  10. A Genotypic Analysis of Five P. aeruginosa Strains after Biofilm Infection by Phages Targeting Different Cell Surface Receptors

    Directory of Open Access Journals (Sweden)

    Diana P. Pires

    2017-06-01

    Full Text Available Antibiotic resistance constitutes one of the most serious threats to the global public health and urgently requires new and effective solutions. Bacteriophages are bacterial viruses increasingly recognized as being good alternatives to traditional antibiotic therapies. In this study, the efficacy of phages, targeting different cell receptors, against Pseudomonas aeruginosa PAO1 biofilm and planktonic cell cultures was evaluated over the course of 48 h. Although significant reductions in the number of viable cells were achieved for both cases, the high level of adaptability of the bacteria in response to the selective pressure caused by phage treatment resulted in the emergence of phage-resistant variants. To further investigate the genetic makeup of phage-resistant variants isolated from biofilm infection experiments, some of these bacteria were selected for phenotypic and genotypic characterization. Whole genome sequencing was performed on five phage-resistant variants and all of them carried mutations affecting the galU gene as well as one of pil genes. The sequencing analysis further revealed that three of the P. aeruginosa PAO1 variants carry large deletions (>200 kbp in their genomes. Complementation of the galU mutants with wild-type galU in trans restored LPS expression on the bacterial cell surface of these bacterial strains and rendered the complemented strains to be sensitive to phages. This provides unequivocal evidence that inactivation of galU function was associated with resistance to the phages that uses LPS as primary receptors. Overall, this work demonstrates that P. aeruginosa biofilms can survive phage attack and develop phage-resistant variants exhibiting defective LPS production and loss of type IV pili that are well adapted to the biofilm mode of growth.

  11. Effects of quorum-sensing on immunoglobulin G responses in a rat model of chronic lung infection with Pseudomonas aeruginosa

    DEFF Research Database (Denmark)

    WU, H.; Song, Z.J.; Givskov, Michael Christian

    2004-01-01

    Levels of serum antibodies against Pseudomonas aeruginosa were observed for 106 days in a rat model of chronic lung infection. Significantly weaker responses of serum IgG and IgG1 and a lower ratio of IgGI/IgG2a were found in the rats infected with the quorum-signal-deficient mutant, PAO1 (rhl......I, lasI), compared with the wild-type PAO1. Four out of 15 rats infected with wild-type PAO1 contained bacteria in the lungs on day 106, whereas no bacteria were found in the mutant PAO1 group. The results indicate that quorum signals contribute to the persistence of the infection and influence...

  12. Microalgal sensitivity varies between a diuron-resistant strain and two wild strains when exposed to diuron and irgarol, alone and in mixtures

    OpenAIRE

    Dupraz, Valentin; Coquille, Nathalie; Menard, Dominique; Sussarellu, Rossana; Haugarreau, Larissa; Stachowski-haberkorn, Sabine

    2016-01-01

    A wild strain of Chaetoceros calcitrans and wild and diuron-resistant strains of Tetraselmis suecica, were exposed to the PSII inhibitor herbicides diuron and irgarol, individually and in mixtures. The effects of three concentrations of diuron and irgarol and four binary mixtures were evaluated on doubling time, relative reactive oxygen species and lipid content by flow cytometry, and on photosynthetic efficiency by pulse amplitude modulated fluorescence. In both wild strains, significant...

  13. Effect of bacteriocin and exopolysaccharides isolated from probiotic on P. aeruginosa PAO1 biofilm.

    Science.gov (United States)

    Sharma, Vivek; Harjai, Kusum; Shukla, Geeta

    2018-03-01

    Microorganisms develop biofilms on indwelling medical devices and are associated with biofilm-related infections, resulting in substantial morbidity and mortality. Therefore, to prevent and control biofilm-associated infections, the present study was designed to assess the anti-biofilm potential of postbiotics derived from probiotic organisms against most prevalent biofilm-forming Pseudomonas aeruginosa PAO1. Eighty lactic acid bacteria isolated from eight neonatal fecal samples possessed antibacterial activity against P. aeruginosa PAO1. Among these, only four lactic acid bacteria produced both bacteriocin and exopolysaccharides but only one isolate was found to maximally attenuate the P. aeruginosa PAO1 biofilm. More specifically, the phenotypic and probiotic characterization showed that the isolated lactic acid bacteria were gram positive, non-motile, and catalase and oxidase negative; tolerated acidic and alkaline pH; has bile salt concentration; showed 53% hydrophobicity; and was found to be non-hemolytic. Phylogenetically, the organism was found to be probiotic Lactobacillus fermentum with accession no. KT998657. Interestingly, pre-coating of a microtiter plate either with bacteriocin or with exopolysaccharides as well as their combination significantly (p < 0.05) reduced the number of viable cells forming biofilms to 41.7% compared with simultaneous coating of postbiotics that had 72.4% biofilm-forming viable cells as observed by flow cytometry and confocal laser scanning microscopy. Therefore, it can be anticipated that postbiotics as the natural biointerventions can be employed as the prophylactic agents for medical devices used to treat gastrointestinal and urinary tract infections.

  14. Development of a genetic sexing strain in Bactrocera carambolae (Diptera: Tephritidae) by introgression of sex sorting components from B. dorsalis, Salaya1 strain.

    Science.gov (United States)

    Isasawin, Siriwan; Aketarawong, Nidchaya; Lertsiri, Sittiwat; Thanaphum, Sujinda

    2014-01-01

    The carambola fruit fly, Bactrocera carambolae Drew & Hancock is a high profile key pest that is widely distributed in the southwestern ASEAN region. In addition, it has trans-continentally invaded Suriname, where it has been expanding east and southward since 1975. This fruit fly belongs to Bactrocera dorsalis species complex. The development and application of a genetic sexing strain (Salaya1) of B. dorsalis sensu stricto (s.s.) (Hendel) for the sterile insect technique (SIT) has improved the fruit fly control. However, matings between B. dorsalis s.s. and B. carambolae are incompatible, which hinder the application of the Salaya1 strain to control the carambola fruit fly. To solve this problem, we introduced genetic sexing components from the Salaya1 strain into the B. carambolae genome by interspecific hybridization. Morphological characteristics, mating competitiveness, male pheromone profiles, and genetic relationships revealed consistencies that helped to distinguish Salaya1 and B. carambolae strains. A Y-autosome translocation linking the dominant wild-type allele of white pupae gene and a free autosome carrying a recessive white pupae homologue from the Salaya1 strain were introgressed into the gene pool of B. carambolae. A panel of Y-pseudo-linked microsatellite loci of the Salaya1 strain served as markers for the introgression experiments. This resulted in a newly derived genetic sexing strain called Salaya5, with morphological characteristics corresponding to B. carambolae. The rectal gland pheromone profile of Salaya5 males also contained a distinctive component of B. carambolae. Microsatellite DNA analyses confirmed the close genetic relationships between the Salaya5 strain and wild B. carambolae populations. Further experiments showed that the sterile males of Salaya5 can compete with wild males for mating with wild females in field cage conditions. Introgression of sex sorting components from the Salaya1 strain to a closely related B. carambolae

  15. 5-Fluorouracil-resistant strain of Methanobacterium thermoautotrophicum.

    Science.gov (United States)

    Nagle, D P; Teal, R; Eisenbraun, A

    1987-09-01

    Growth of Methanobacterium thermoautotrophicum Marburg is inhibited by the pyrimidine, 5-fluorouracil (FU). It was shown previously that methanogenesis is not inhibited to the same extent as growth. A spontaneously occurring FU-resistant strain (RTAE-1) was isolated from a culture of strain Marburg. The growth of both strains was inhibited by 5-fluorodeoxyuridine but not 5-fluorocytosine, and the wild type was more susceptible to inhibition by 5-azauracil and 6-azauracil than was strain RTAE-1. The cellular targets for the pyrimidine analogs are not known. When the accumulation of 14C-labeled uracil or FU by the two strains was compared, the wild type took up 15-fold more radiolabel per cell than did the FU-resistant strain. In the wild type, radiolabel from uracil was incorporated into the soluble pool, RNA, and DNA. The metabolism of uracil appeared to involve a uracil phosphoribosyltransferase activity. Strain Marburg extracts contained this enzyme, whereas FU-resistant strain RTAE-1 extracts had less than 1/10 as much activity. Although it is possible that a change in permeability to the compounds plays a role in the stable resistance of strain RTAE-1, the fact that it lacks the ability to metabolize pyrimidines to nucleotides is sufficient to account for its phenotype.

  16. Murine FATP alleviates growth and biochemical deficiencies of yeast fat1Delta strains

    DEFF Research Database (Denmark)

    Dirusso, C C; Connell, E J; Færgeman, Nils J.

    2000-01-01

    following incubation of the cells with exogenous oleate. Expression of either Fat1p or murine FATP from a plasmid in a fat1Delta strain restored these phenotypic and biochemical deficiencies. Fat1p and FATP restored growth of fat1Delta cells in the presence of cerulenin and under hypoxic conditions....... Furthermore, fatty-acid transport was restored and was found to be chain length specific: octanoate, a medium-chain fatty acid was transported in a Fat1p- and FATP-independent manner while the long-chain fatty acids myristate, palmitate, and oleate required either Fat1p or FATP for maximal levels of transport....... Lignoceryl CoA synthetase activities were restored to wild-type levels in fat1Delta strains expressing either Fat1p or FATP. Fat1p or FATP also restored wild-type levels of beta-oxidation of exogenous long-chain fatty acids. These data show that Fat1p and FATP are functionally equivalent when expressed...

  17. Comparison of Ehrlichia muris strains isolated from wild mice and ticks and serologic survey of humans and animals with E. muris as antigen.

    Science.gov (United States)

    Kawahara, M; Ito, T; Suto, C; Shibata, S; Rikihisa, Y; Hata, K; Hirai, K

    1999-04-01

    In metropolitan Tokyo, the Ehrlichia muris seropositivity rate of 24 wild mice was 63% in Hinohara Village, but in the surrounding areas, it was 0 to 5%. This finding suggests that the reservoir of E. muris is focal. Among the 15 seropositive mice, ehrlichiae were isolated from 9 Apodemus speciosus mice and 1 A. argenteus mouse, respectively. Five ehrlichial isolates were obtained from 10 ticks (Haemaphysalis flava) collected in Asuke Town, Aichi Prefecture, where the E. muris type strain had been isolated. These new isolates were compared with the E. muris type strain. The mouse virulence and ultrastructure of the new isolates were similar to those of the type strain, and all of them were cross-reactive with each other, as well as with the type strain, by indirect immunofluorescent-antibody test. The levels of similarity of the base sequences of the 16S rRNA gene of one of the A. speciosus isolates and one of the tick isolates to that of the E. muris type strain were 99.79 and 99.93%, respectively. We suggest that all of these isolates are E. muris; that E. muris is not limited to Eothenomys kageus but infects other species of mice; and that E. muris is present at locations other than Aichi Prefecture. It appears that H. flava is a potential vector of E. muris. Twenty (1%) of 1803 humans from metropolitan Tokyo were found to be seropositive for E. muris antibodies. A serological survey revealed that exposure to E. muris or organisms antigenically cross-reactive to E. muris occurred among dogs, wild mice, monkeys, bears, deer, and wild boars in Gifu Prefecture, nearby prefectures, and Nagoya City, central Japan. However, human beings and Rattus norvegicus rats in this area were seronegative. These results indicate broader geographic distribution of and human and animal species exposure to E. muris or related Ehrlichia spp. in Japan.

  18. Enhanced thermophysical properties via PAO superstructure

    Science.gov (United States)

    Pournorouz, Zahra; Mostafavi, Amirhossein; Pinto, Aditya; Bokka, Apparao; Jeon, Junha; Shin, Donghyun

    2017-01-01

    For the last few years, molten salt nanomaterials have attracted many scientists for their enhanced specific heat by doping a minute concentration of nanoparticles (up to 1% by weight). Likewise, enhancing the specific heat of liquid media is important in many aspects of engineering such as engine oil, coolant, and lubricant. However, such enhancement in specific heat was only observed for molten salts, yet other engineering fluids such as water, ethylene glycol, and oil have shown a decrease of specific heat with doped nanoparticles. Recent studies have shown that the observed specific heat enhancement resulted from unique nanostructures that were formed by molten salt molecules when interacting with nanoparticles. Thus, such enhancement in specific heat is only possible for molten salts because other fluids may not naturally form such nanostructures. In this study, we hypothesized such nanostructures can be mimicked through in situ formation of fabricated nano-additives, which are putative nanoparticles coated with useful organic materials (e.g., polar-group-ended organic molecules) leading to superstructures, and thus can be directly used for other engineering fluids. We first applied this approach to polyalphaolefin (PAO). A differential scanning calorimeter (DSC), a rheometer, and a customized setup were employed to characterize the heat capacity, viscosity, and thermal conductivity of PAO and PAO with fabricated nano-additives. Results showed 44.5% enhanced heat capacity and 19.8 and 22.98% enhancement for thermal conductivity and viscosity, respectively, by an addition of only 2% of fabricated nanostructures in comparison with pure PAO. Moreover, a partial melting of the polar-group-ended organic molecules was observed in the first thermal cycle and the peak disappeared in the following cycles. This indicates that the in situ formation of fabricated nano-additives spontaneously occurs in the thermal cycle to form nanostructures. Figure of merit analyses have

  19. Enhanced thermophysical properties via PAO superstructure.

    Science.gov (United States)

    Pournorouz, Zahra; Mostafavi, Amirhossein; Pinto, Aditya; Bokka, Apparao; Jeon, Junha; Shin, Donghyun

    2017-12-01

    For the last few years, molten salt nanomaterials have attracted many scientists for their enhanced specific heat by doping a minute concentration of nanoparticles (up to 1% by weight). Likewise, enhancing the specific heat of liquid media is important in many aspects of engineering such as engine oil, coolant, and lubricant. However, such enhancement in specific heat was only observed for molten salts, yet other engineering fluids such as water, ethylene glycol, and oil have shown a decrease of specific heat with doped nanoparticles. Recent studies have shown that the observed specific heat enhancement resulted from unique nanostructures that were formed by molten salt molecules when interacting with nanoparticles. Thus, such enhancement in specific heat is only possible for molten salts because other fluids may not naturally form such nanostructures. In this study, we hypothesized such nanostructures can be mimicked through in situ formation of fabricated nano-additives, which are putative nanoparticles coated with useful organic materials (e.g., polar-group-ended organic molecules) leading to superstructures, and thus can be directly used for other engineering fluids. We first applied this approach to polyalphaolefin (PAO). A differential scanning calorimeter (DSC), a rheometer, and a customized setup were employed to characterize the heat capacity, viscosity, and thermal conductivity of PAO and PAO with fabricated nano-additives. Results showed 44.5% enhanced heat capacity and 19.8 and 22.98% enhancement for thermal conductivity and viscosity, respectively, by an addition of only 2% of fabricated nanostructures in comparison with pure PAO. Moreover, a partial melting of the polar-group-ended organic molecules was observed in the first thermal cycle and the peak disappeared in the following cycles. This indicates that the in situ formation of fabricated nano-additives spontaneously occurs in the thermal cycle to form nanostructures. Figure of merit analyses have

  20. Molecular characterization of wild-type measles viruses in Tamil Nadu, India, during 2005-2006: relationship of genotype D8 strains from Tamil Nadu to global strains.

    Science.gov (United States)

    Duraisamy, Raja; Rota, Paul A; Palani, Gunasekaran; Elango, Varalakshmi; Sambasivam, Mohana; Lowe, Luis; Lopareva, Elena; Ramamurty, Nalini

    2012-02-01

    Molecular characterization of measles viruses is a valuable tool for measuring the effectiveness of measles control and elimination programmes. WHO recommends that virological surveillance be conducted during all phases of measles control to document circulation of indigenous strains and trace future importation. This report describes the genetic characterization of wild type measles viruses from Tamil Nadu, India isolated between January 2005 and January 2006. In the study, 304 suspected measles cases (292 from 56 outbreaks and 12 sporadic cases) were investigated. Blood samples were collected from suspected measles outbreaks and 11 suspected sporadic cases and tested for the presence of measles and rubella specific IgM. Based on serological results, 53 outbreaks were confirmed as measles, 2 as a combination of measles and rubella, and 1 negative for both. Eight sporadic cases were confirmed as measles and one as rubella. Throat swab and urine samples were collected for virus isolation and 28 isolates were obtained. Sequencing and analysis showed that 3 isolates belonged to genotype D4 and 25 to genotype D8. Comparison of the genotype D8 sequences from Tamil Nadu with previously reported genotype D8 sequences from India and abroad showed six distinct clusters with Tamil Nadu strains forming two clusters. This study has established baseline molecular data and is the first report that describes genetic diversity of circulating measles strains in Tamil Nadu, a state in India. D8 has multiple lineages and this has been linked with importation of measles into the USA and UK. Copyright © 2011 Wiley Periodicals, Inc.

  1. Effect of nitrofurans and NO generators on biofilm formation by Pseudomonas aeruginosa PAO1 and Burkholderia cenocepacia 370.

    Science.gov (United States)

    Zaitseva, Julia; Granik, Vladimir; Belik, Alexandr; Koksharova, Olga; Khmel, Inessa

    2009-06-01

    Antibacterial drugs in the nitrofuran series, such as nitrofurazone, furazidin, nitrofurantoin and nifuroxazide, as well as the nitric oxide generators sodium nitroprusside and isosorbide mononitrate in concentrations that do not suppress bacterial growth, were shown to increase the capacity of pathogenic bacteria Pseudomonas aeruginosa PAO1 and Burkholderia cenocepacia 370 to form biofilms. At 25-100microg/ml, nitrofurans 2-2.5-fold enhanced biofilm formation of P. aeruginosa PAO1, and NO donors 3-6-fold. For B. cenocepacia 370, the enhancement was 2-5-fold (nitrofurans) and 4.5-fold (sodium nitroprusside), respectively.

  2. Duplex PCR for differentiation of the vaccine strain Brucella suis S2 and B. suis biovar 1 from other strains of Brucella spp.

    Science.gov (United States)

    Nan, Wenlong; Tan, Pengfei; Wang, Yong; Xu, Zouliang; Mao, Kairong; Peng, Daxin; Chen, Yiping

    2014-09-01

    Immunisation with attenuated Brucella spp. vaccines prevents brucellosis, but may also interfere with diagnosis. In this study, a duplex PCR was developed to distinguish Brucella suis vaccine strain S2 from field strains of B. suis biovar 1 and other Brucella spp. The PCR detected 60 fg genomic DNA of B. suis S2 or biovar 1 field strains and was able to distinguish B. suis S2 and wild-type strains of B. suis biovar 1 among 76 field isolates representing all the common species and biovars, as well as four vaccine strains, of Brucella. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Alterations of OprD in Carbapenem-Intermediate and -Susceptible Strains of Pseudomonas aeruginosa Isolated from Patients with Bacteremia in a Spanish Multicenter Study

    Science.gov (United States)

    Cabot, Gabriel; Rodríguez, Cristina; Roman, Elena; Tubau, Fe; Macia, María D.; Moya, Bartolomé; Zamorano, Laura; Suárez, Cristina; Peña, Carmen; Domínguez, María A.; Moncalián, Gabriel; Oliver, Antonio; Martínez-Martínez, Luis

    2012-01-01

    We investigated the presence of OprD mutations in 60 strains of metallo-ß-lactamase-negative Pseudomonas aeruginosa intermediately susceptible (IS [n = 12]; MIC = 8 μg/ml) or susceptible (S [n = 48]; MICs ≤ 1 to 4 μg/ml) to imipenem and/or meropenem that were isolated from patients with bacteremia in order to evaluate their impact on carbapenem susceptibility profiles. The presence of mutations in oprD was detected by sequencing analysis. OprD expression was assessed by both outer membrane protein (OMP) analysis and real-time PCR (RT-PCR). Fourteen (23%) isolates had an OprD identical to that of PAO1, and OprD modifications were detected in 46 isolates (77%). Isolates were classified as OprD “full-length types” (T1 [n = 40, including both wild-type OprD and variants showing several polymorphisms]) and OprD “deficient types” (T2 [n = 3 for OprD frameshift mutations] and T3 [n = 17 for premature stop codons in oprD]). RT-PCR showed that 5 OprD type T1 isolates presented reduced transcription of oprD (0.1- to 0.4-fold compared to PAO1), while oprD levels increased more than 2-fold over that seen with PAO1 in 4 OprD type T1 isolates. A total of 50% of the isolates belonging to OprD “deficient types” were susceptible to both carbapenems, and 40% were susceptible to meropenem and intermediately susceptible to imipenem. Only one isolate (5%) within this group was intermediately susceptible to both carbapenems, and one (5%) was susceptible to imipenem and intermediately susceptible to meropenem. We concluded that OprD inactivating mutations in clinical isolates of P. aeruginosa are not restricted only to carbapenem-resistant isolates but are also found in isolates with imipenem or meropenem MICs of only 0.06 to 4 μg/ml. PMID:22290967

  4. High-resolution melt PCR analysis for rapid identification of Chlamydia abortus live vaccine strain 1B among C. abortus strains and field isolates.

    Science.gov (United States)

    Vorimore, Fabien; Cavanna, Noémie; Vicari, Nadia; Magnino, Simone; Willems, Hermann; Rodolakis, Annie; Siarkou, Victoria I; Laroucau, Karine

    2012-09-01

    We describe a novel high-resolution melt assay that clearly differentiates Chlamydia abortus live vaccine strain 1B from field C. abortus strains and field wild-type isolates based on previously described single nucleotide polymorphisms. This modern genotyping technique is inexpensive, easy to use, and less time-consuming than PCR-RFLP. Copyright © 2012 Elsevier B.V. All rights reserved.

  5. Pigments influence the tolerance of Pseudomonas aeruginosa PAO1 to photodynamically induced oxidative stress

    DEFF Research Database (Denmark)

    Orlandi, Viviana T; Bolognese, Fabrizio; Chiodaroli, Luca

    2015-01-01

    by exogenous photosensitizers and visible light. To evaluate whether P. aeruginosa pigments can contribute to its relative tolerance to PDT, we analysed the response to this treatment of isogenic transposon mutants of P. aeruginosa PAO1 with altered pigmentation. In general, in the presence of pigments...

  6. Antibody induced by immunization with the Jeryl Lynn mumps vaccine strain effectively neutralizes a heterologous wild-type mumps virus associated with a large outbreak.

    Science.gov (United States)

    Rubin, Steven A; Qi, Li; Audet, Susette A; Sullivan, Bradley; Carbone, Kathryn M; Bellini, William J; Rota, Paul A; Sirota, Lev; Beeler, Judy

    2008-08-15

    Recent mumps outbreaks in older vaccinated populations were caused primarily by genotype G viruses, which are phylogenetically distinct from the genotype A vaccine strains used in the countries affected by the outbreaks. This finding suggests that genotype A vaccine strains could have reduced efficacy against heterologous mumps viruses. The remote history of vaccination also suggests that waning immunity could have contributed to susceptibility. To examine these issues, we obtained consecutive serum samples from children at different intervals after vaccination and assayed the ability of these samples to neutralize the genotype A Jeryl Lynn mumps virus vaccine strain and a genotype G wild-type virus obtained during the mumps outbreak that occurred in the United States in 2006. Although the geometric mean neutralizing antibody titers against the genotype G virus were approximately one-half the titers measured against the vaccine strain, and although titers to both viruses decreased with time after vaccination, antibody induced by immunization with the Jeryl Lynn mumps vaccine strain effectively neutralized the outbreak-associated virus at all time points tested.

  7. Salmonella spp. and antibiotic-resistant strains in wild mammals and birds in north-western Italy from 2002 to 2010

    Directory of Open Access Journals (Sweden)

    Velca Botti

    2013-06-01

    Full Text Available Salmonella is an important zoonotic pathogen of economic importance. In Europe, salmonellosis is the second food-borne infection, in Italy, Salmonella is still the major cause of food-borne outbreaks. In Europe, there are many Salmonella surveillance plans on farmed animals, while Salmonella survey of wild animals is occasionally performed. The aim of this study was to investigate the presence of Salmonella including the antibiotic-resistant strains in wild animals. Between 2002 and 2010, 2,713 wild animals (canids, mustelids, birds, rodents, ungulates, were collected in north-western Italy and tested for Salmonella by classical microbiological culture method followed by serological and biochemical typing. One hundred and seventeen wild animals (63 canids, 25 mustelids, 24 birds, 5 ungulates were found positive for Salmonella (4.3%. One hundred and thirty strains, belonging to several serotypes were isolated, and S. Typhimurium was the most common serotype found. Antibiotic susceptibility was tested by disk-diffusion test on 88 strains. Almost all the analyzed strains (97.7% showed resistance/intermediate resistance to at least one class of antibiotics and the highest resistance values were observed for the tetracycline class. In conclusion, zoonotic and antibiotic-resistant serotypes were found in many species of wildlife.

  8. [Use of ITS and ISSR markers in the molecular characterisation of Pleurotus djamor hybrid strains].

    Science.gov (United States)

    Aguilar Doroteo, Leticia; Zárate Segura, Paola Berenice; Villanueva Arce, Ramón; Yáñez Fernández, Jorge; Garín Aguilar, María Eugenia; Guadarrama Mendoza, Paula Cecilia; Valencia Del Toro, Gustavo

    Molecular characterisation of wild type Pleurotus species is important for germplasm conservation and its further use for genetic improvement. No molecular studies have been performed with monokaryons used for producing hybrid strains, either with the reconstituted strains obtained by pairing those monokaryons. The molecular characterisation of parental dikaryons, hybrid, and reconstituted strains as well as monokaryotic strains, is therefore of utmost importance. To carry out the molecular identification of Pleurotus djamor strains, i.e. dikaryotic wild type strains, hybrid strains, and the monokaryotic strains used for the hybrid formation. Five wild type strains of P. djamor from different states in Mexico were collected and molecularly identified by sequencing the ITS1-5.8-ITS2 region using ITS1 and ITS4 universal oligonucleotides. Four hybrid strains were obtained by pairing neohaplonts of two wild type strains selected. Six ISSR markers were used for the molecular characterisation of monokaryotic and dikaryotic strains. Using the ITS markers, an amplified product of 700bp was obtained in five wild type strains, with a 99-100% similarity with P. djamor. A total of 95 fragments were obtained using the ISSR markers, with 99% of polymorphism. Wild type strains were identified as P. djamor, and were clearly grouped with Mexican strains from other states of Mexico. ISSR markers allowed the generation of polymorphic bands in monokaryotic and dikaryotic strains, splitting both types of strains. The high degree of polymorphism indicates the genetic diversity of P. djamor, an advantage in mushroom production and in the improving of the species. Copyright © 2017 Asociación Española de Micología. Publicado por Elsevier España, S.L.U. All rights reserved.

  9. A study of single nucleotide polymorphism in the ystB gene of Yersinia enterocolitica strains isolated from various wild animal species.

    Science.gov (United States)

    Bancerz-Kisiel, Agata; Szczerba-Turek, Anna; Platt-Samoraj, Aleksandra; Michalczyk, Maria; Szweda, Wojciech

    2017-03-01

    Y. enterocolitica is the causative agent of yersiniosis. The objective of the article was a study of single nucleotide polymorphism in the ystB gene of Y. enterocolitica strains isolated from various wild animal species. High-resolution melting (HRM) analysis was applied to identify single nucleotide polymorphism (SNP) of ystB gene fragments of 88 Y. enterocolitica biotype 1A strains isolated from wild boar, roe deer, red deer and wild ducks. HRM analysis revealed 14 different melting profiles - 4 of them were defined as regular genotypes (G1, G2, G3, G4), whereas 10 as variations. 24 of the examined Y. enterocolitica strains were classified as G1, 18 strains as a G2, 21 strains as a G3, and 15 strains as a G4. Nucleotide sequences classified as G1 revealed 100% similarity with the Y. enterocolitica D88145.1 sequence (NCBI). Analysis of G2 revealed one point mutation - transition T111A. One mutation was also found in G3, but SNP was placed in a different gene region - transition G193A. Two SNPs - transitions G92C and T111A - were identified in G4. Direct sequencing of 10 variations revealed 5 new variants of the ystB nucleotide sequence: V1 - transition G129A (3 strains); V2 - transitions T111A and G193A (2 strains); V3 - transitions C118T and G193A (1 strain); V4 - transitions C141A and G193A (2 strains); and V5 characterized by 19 SNPs: G83A, T93A, A109G, G114T, C116T, A123G, T134C, T142G, T144C, A150C, G162A, T165G, T170G, T174A, T177G, G178A, A179G, A184G and G193A (2 strains). The predominant genotype in isolates from wild ducks was G1; in red deer G2; in wild boar G3; in roe deer G1 and G4. The proposed HRM method could be used to analyze Y. enterocolitica biotype 1A strains isolated from different sources, including humans.

  10. Study of probiotic potential of four wild Lactobacillus rhamnosus strains.

    Science.gov (United States)

    Tuo, Yanfeng; Zhang, Weiqin; Zhang, Lanwei; Ai, Lianzhong; Zhang, Yingchun; Han, Xue; Yi, Huaxi

    2013-06-01

    The four wild Lactobacillus rhamnosus strains were examined in vitro for resistance to simulated gastro and intestinal juices, adhesion to HT-29 cells, antagonistic activity against enteric pathogens and immunomodulating activity. The strains L. rhamnosus SB5L, J5L and IN1L were able to survive in simulated gastro juice while the strain L. rhamnosus SB31L lost viability exposed to simulated gastro juice for 3 h. The four strains had high viability in simulated small intestinal juice with little loss (<1.0 cycle reduction). The strains SB5L, J5L and IN1L antagonized against Escherichia coli ATCC 25922, Salmonella enterica serovar Typhimurium ATCC 14028, Shigella sonnei ATCC 25931. The strain L. rhamnosus IN1L had the highest adhesive capability to HT-29 cells in vitro (251 bacteria cells per 100 HT-29 cells) compared to the other three L. rhamnosus strains. The live bacteria, cell wall and DNA of the four L. rhamnosus induced the secretion of pro-inflammatory cytokines IL-12 (p70), IFN-γ and TNF-α by human peripheral blood mononuclear cells (PBMCs). The levels of IL-12 (p70), IFN-γ and TNF-α produced by stimulated PBMCs were significantly higher (P < 0.05) than those of the control. Those data indicated that the four L. rhamnosus strains have the potential as the probiotic for human being use, although further studies are still needed. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

  11. Control of acute, chronic, and constitutive hyperammonemia by wild-type and genetically engineered Lactobacillus plantarum in rodents.

    Science.gov (United States)

    Nicaise, Charles; Prozzi, Deborah; Viaene, Eric; Moreno, Christophe; Gustot, Thierry; Quertinmont, Eric; Demetter, Pieter; Suain, Valérie; Goffin, Philippe; Devière, Jacques; Hols, Pascal

    2008-10-01

    Hyperammonemia is a common complication of acute and chronic liver diseases. Often accompanied with side effects, therapeutic interventions such as antibiotics or lactulose are generally targeted to decrease the intestinal production and absorption of ammonia. In this study, we aimed to modulate hyperammonemia in three rodent models by administration of wild-type Lactobacillus plantarum, a genetically engineered ammonia hyperconsuming strain, and a strain deficient for the ammonia transporter. Wild-type and metabolically engineered L. plantarum strains were administered in ornithine transcarbamoylase-deficient Sparse-fur mice, a model of constitutive hyperammonemia, in a carbon tetrachloride rat model of chronic liver insufficiency and in a thioacetamide-induced acute liver failure mice model. Constitutive hyperammonemia in Sparse-fur mice and hyperammonemia in a rat model of chronic hepatic insufficiency were efficiently decreased by Lactobacillus administration. In a murine thioacetamide-induced model of acute liver failure, administration of probiotics significantly increased survival and decreased blood and fecal ammonia. The ammonia hyperconsuming strain exhibited a beneficial effect at a lower dose than its wild-type counterpart. Improved survival in the acute liver failure mice model was associated with lower blood ammonia levels but also with a decrease of astrocyte swelling in the brain cortex. Modulation of ammonia was abolished after administration of the strain deficient in the ammonium transporter. Intestinal pH was clearly lowered for all strains and no changes in gut flora were observed. Hyperammonemia in constitutive model or after acute or chronic induced liver failure can be controlled by the administration of L. plantarum with a significant effect on survival. The mechanism involved in this ammonia decrease implicates direct ammonia consumption in the gut.

  12. Technetium-labeled HM-PAO studies in patients with cerebrovascular disease

    International Nuclear Information System (INIS)

    Smith, F.W.; Sharp, P.F.; Gemmell, H.; Evans, N.T.; MacDonald, A.F.

    1986-01-01

    Technetium-labeled hexamethyl-propyleneamineoxime (HM-PAO) is a promising radiopharmaceutical for the demonstration of cerebral blood flow. Twenty-four patients who had experienced either acute stroke (AS) or transient ischemic attack (TIA) were studied by x-ray CT and SPECT using technetium-labeled HM-PAO total of 26 studies. HM-PAO has a cerebral distribution similar to that of iodoamphetamine, but labeling with technetium allows good SPECT imaging on demand in any nuclear medicine department. In ten of the 16 patients who had experienced AS, findings on HM-PAO and CT studies correlated well. In six patients reduced cortical perfusion was detected on HM-PAO imaging, but only small infarcts in the internal capsule were seen on CT. In four of the eight patients who had experienced TIA, neither study revealed any abnormality. In the remaining four, areas of cortical underperfusion were seen on HM-PAO imaging, whereas the CT examination was normal. The findings in this study suggest that HM-PAO imaging is a more sensitive method for demonstrating the extent of cerebral underperfusion in cases of cerebrovascular accident

  13. ABC Transporter for Corrinoids in Halobacterium sp. Strain NRC-1

    OpenAIRE

    Woodson, Jesse D.; Reynolds, April A.; Escalante-Semerena, Jorge C.

    2005-01-01

    We report evidence for the existence of a putative ABC transporter for corrinoid utilization in the extremely halophilic archaeon Halobacterium sp. strain NRC-1. Results from genetic and nutritional analyses of Halobacterium showed that mutants with lesions in open reading frames (ORFs) Vng1370G, Vng1371Gm, and Vng1369G required a 105-fold higher concentration of cobalamin for growth than the wild-type or parent strain. The data support the conclusion that these ORFs encode orthologs of the b...

  14. Interleukin-1 receptor type I gene-deficient mice are less susceptible to Staphylococcus epidermidis biomaterial-associated infection than are wild-type mice

    NARCIS (Netherlands)

    Boelens, J. J.; van der Poll, T.; Zaat, S. A.; Murk, J. L.; Weening, J. J.; Dankert, J.

    2000-01-01

    Elevated concentrations of interleukin-1 (IL-1) were found in tissue surrounding biomaterials infected with Staphylococcus epidermidis. To determine the role of IL-1 in biomaterial-associated infection (BAI), IL-1 receptor type I-deficient (IL-1R(-/-)) and wild-type mice received subcutaneous

  15. Antibody titers against vaccine and contemporary wild poliovirus type 1 in children immunized with IPV+OPV and young adults immunized with OPV.

    Science.gov (United States)

    Lukashev, Alexander N; Yarmolskaya, Maria S; Shumilina, Elena Yu; Sychev, Daniil A; Kozlovskaya, Liubov I

    2016-02-02

    In 2010, a type 1 poliovirus outbreak in Congo with 445 lethal cases was caused by a virus that was neutralized by sera of German adults vaccinated with inactivated polio vaccine with a reduced efficiency. This seroprevalence study was done in two cohorts immunized with other vaccination schedules. Russian children aged 3-6 years immunized with a combination of inactivated and live polio vaccines were reasonably well protected against any wild type poliovirus 1, including the Congolese isolate. Adults aged 20-29 years immunized only with live vaccine were apparently protected against the vaccine strain (92% seropositive), but only 50% had detectable antibodies against the Congo-2010 isolate. Both waning immunity and serological divergence of the Congolese virus could contribute to this result. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Evaluation of pathogenesis caused in cattle and guinea pig by a Mycobacterium bovis strain isolated from wild boar

    Directory of Open Access Journals (Sweden)

    Di Rienzo Julio

    2011-07-01

    Full Text Available Abstract Background In many regions of the world, wild mammals act as reservoir of Mycobacterium bovis, a situation that prevents the eradication of bovine tuberculosis. In order to observe whether a strain isolated from a wild boar, previously tested as highly virulent in a mice model, is also virulent in cattle, we performed cattle experimental inoculation with this strain Results Groups of Friesian calves were either infected with the wild boar strain M. bovis 04-303 or with the bovine strain NCTC10772 as a control. We found that antigen-specific IFN-γ release in whole blood samples occurred earlier in animals infected with M. bovis 04-303. Both M. bovis strains resulted in a positive skin test, with animals infected with the wild boar isolate showing a stronger response. These results and the presence of more severe organ lesions, with granuloma and pneumonic areas in cattle demonstrate that the wild boar isolate is more virulent than the NCTC10772 strain. Additionally, we tested the infectivity of the M. bovis strains in guinea pigs and found that M. bovis 04-303 had the highest pathogenicity. Conclusions M. bovis strains isolated from wild boars may be pathogenic for cattle, producing TB lesions.

  17. Repair of gamma radiation damage in wild type and a radiation sensitive mutant of Deinococcus radiodurans

    International Nuclear Information System (INIS)

    Mizuma, Nagayo

    1989-01-01

    In an effort to examine production and repair of radiation-induced single and double strand breaks in the DNA, a repair-deficient wild type and a repair-deficient mutant, UV17, of Deinococcus radiodurans were subjected to Co-60 gamma irradiation at a dose rate of 6.3 kGy/hr for wild type and 3.9 kGy/hr for UV17 mutant. The shoulder of the curve of UV17 mutant was narrow but existed with the intercept of 0.7 kGy and the corresponding value of the wild type was 4.2 kGy. Mutant cells exhibited about 6 fold increases in sensitivity for the shoulder relative to the wild type. The D 37 doses in the wild type and the mutant were 0.57 kGy and 0.25 kGy, respectively. From the survival curves, difference in the sensitivity between two strains was mainly due to difference of repair capacity than the number of radiation sensitive target. Sedimentation rate of the main component in the irradiated cells of UV17 mutant increased almost to the level of unirradiated control by the postincubation at 30deg C for 3 hrs. The results indicated that this sensitive mutant also exhibited an ability to restore single strand breaks after exposure to a sublethal dose of 0.6 kGy. When restitution of double strand breaks was analyzed by sedimentation in a neutral sucrose gradient, the wild type showed restitution to DNA-membrane complex from large part of the breaks. For UV17 mutant, the apparent increase in DNA-membrane complex formation was seen after 3 hours incubation. Large part of the decrease in the activities of peak 2 was recovered in the peak 1 for the wild type. For the mutant, there was little restitution to peak 1. Almost free DNA component in UV17 mutant, therefore, was merely degraded into shorter pieces. Restoration of DNA-membrane complex from free DNA derived from gamma-ray induced double strand scission involved closely in the repair of gamma-induced damage and survival. (N.K.)

  18. Mineral phosphate solubilization by wild type and radiation induced mutants of pantoea dispersa and pantoea terrae

    International Nuclear Information System (INIS)

    Murugesan, Senthilkumar; Lee, Young Keun; Kim, Jung Hun

    2009-01-01

    Three mineral phosphate solubilizing (MPS) bacteria where isolated from rhizosphere soil samples of common bean and weed plants. 16S rDNA analysis indicated that the isolate P2 and P3 are closely related to Pantoea dispersa while isolate P4 is closely related to Pantoea terrae. Islates P2 and P3 recorded 381.60 μg ml -1 of tricalcium phosphate (TCP) solubilization respectively on 3 days incubation. Isolate P4 recorded the TCP solubilization of 215.85 μg ml -1 and the pH was dropped to 4.44 on 24 h incubation. Further incubation of P4 sharply decreased the available phosphorous to 28.94 μg ml -1 and pH level was raised to 6.32. Gamma radiation induced mutagenesis was carried out at LD 99 dose of the wild type strains. The total of 14 mutant clones with enhanced MPS activity and 4 clones with decreased activity were selected based on solubilization index (SI) and phosphate solubilization assay. Mutant P2-M1 recorded the highest P-solubilizing potential among any other wild or mutnat clones by releasing 504.21 μg ml -1 of phosphorous i.e. 35% higher than its wild type by the end of day 5. A comparative evaluation of TCP solubilization by wild type isolates of Pantoea and their mutants, led to select three MPS mutant clones such as P2-M1, P3-M2 and P3-M4 with a potential to release >471.67 μg ml 1 of phosphorous from TCP. These over expressing mutant clones are considered as suitable candidates for biofertilization

  19. Thermal conductivity improvement in carbon nanoparticle doped PAO oil: An experimental study

    Science.gov (United States)

    Shaikh, S.; Lafdi, K.; Ponnappan, R.

    2007-03-01

    The present work involves a study on the thermal conductivity of nanoparticle-oil suspensions for three types of nanoparticles, namely, carbon nanotubes (CNTs), exfoliated graphite (EXG), and heat treated nanofibers (HTT) with PAO oil as the base fluid. To accomplish the above task, an experimental analysis is performed using a modern light flash technique (LFA 447) for measuring the thermal conductivity of the three types of nanofluids, for different loading of nanoparticles. The experimental results show a similar trend as observed in literature for nanofluids with a maximum enhancement of approximately 161% obtained for the CNT-PAO oil suspension. The overall percent enhancements for different volume fractions of the nanoparticles are highest for the CNT-based nanofluid, followed by the EXG and the HTT. The findings from this study for the three different types of carbon nanoparticles can have great potential in the field of thermal management.

  20. PAO mud boosts ROP, minimizes enviro impact

    International Nuclear Information System (INIS)

    Anon.

    1993-01-01

    A North Sea well drilled with a drilling fluid based on polyalphaolefin (PAO) chemistry has helped increase penetration rates and reduce torque and drag while minimizing environmental impact, according to a paper presented at the 1993 SPE/IADC Drilling Conference in Amsterdam. The paper, ''Superior Performance with Minimal Environmental Impact: A Novel Non-Aqueous Drilling Fluid'' (SPE/IADC 25753), written by J.E. Friedheim and R. Pantermuehl of M-I Drilling Fluids, says the rate of penetration was some 15% higher than in offset wells drilled with mineral-oil-base mud. Average penetration rates at the beginning of the 8,856-ft (2,700-m) 12 1/4-in. interval drilled exceeded 100 ft/hr (30.5 m/hr) and averaged higher than 90 ft/hr (27.4 m/hr) for the entire section. The authors attributed the performance to better hole cleaning. Hole cleaning, lubricity, inhibition and equivalent bottom-hole density were primary concerns while drilling the well. ''Environmental aspects of the PAO fluid show that it should be essentially non-toxic to aquatic life,'' the authors contended. ''Various toxicity, bioaccumulation and biodegradation work indicate that the PAO mud will have little impact on the environment while slowly biodegrading.''

  1. Development of antibiotic resistance and up-regulation of the antimutator gene pfpI in mutator Pseudomonas aeruginosa due to inactivation of two DNA oxidative repair genes (mutY, mutM)

    DEFF Research Database (Denmark)

    Mandsberg, Lotte Frigaard; Macia, Maria D.; Bergmann, Kirsten R.

    2011-01-01

    showed only a fivefold increase, whereas the single mutant PAOMMgm (mutM) showed a nonsignificant increase in MR compared with PAO1 and the single mutants. Mutations in the regulator nfxB leading to hyperexpression of MexCD-OprJ efflux pump were found as the mechanism of resistance to ciprofloxacin....... In this study, we constructed a double mutant in mutY and mutM (PAOMY-Mgm) and characterized the phenotype and the gene expression profile using microarray and RT-PCR. PAOMY-Mgm presented 28-fold increases in MR compared with wild-type reference strain PAO1. In comparison, the PAOMYgm (mutY) single mutant...... in the double mutant. A better fitness of the mutator compared with PAO1 was found in growth competition experiments in the presence of ciprofloxacin at concentrations just below minimal inhibitory concentration. Up-regulation of the antimutator gene pfpI, that has been shown to provide protection to oxidative...

  2. Genetic homogeneity of Clostridium botulinum type A1 strains with unique toxin gene clusters.

    Science.gov (United States)

    Raphael, Brian H; Luquez, Carolina; McCroskey, Loretta M; Joseph, Lavin A; Jacobson, Mark J; Johnson, Eric A; Maslanka, Susan E; Andreadis, Joanne D

    2008-07-01

    A group of five clonally related Clostridium botulinum type A strains isolated from different sources over a period of nearly 40 years harbored several conserved genetic properties. These strains contained a variant bont/A1 with five nucleotide polymorphisms compared to the gene in C. botulinum strain ATCC 3502. The strains also had a common toxin gene cluster composition (ha-/orfX+) similar to that associated with bont/A in type A strains containing an unexpressed bont/B [termed A(B) strains]. However, bont/B was not identified in the strains examined. Comparative genomic hybridization demonstrated identical genomic content among the strains relative to C. botulinum strain ATCC 3502. In addition, microarray data demonstrated the absence of several genes flanking the toxin gene cluster among the ha-/orfX+ A1 strains, suggesting the presence of genomic rearrangements with respect to this region compared to the C. botulinum ATCC 3502 strain. All five strains were shown to have identical flaA variable region nucleotide sequences. The pulsed-field gel electrophoresis patterns of the strains were indistinguishable when digested with SmaI, and a shift in the size of at least one band was observed in a single strain when digested with XhoI. These results demonstrate surprising genomic homogeneity among a cluster of unique C. botulinum type A strains of diverse origin.

  3. 5-Fluorouracil-resistant strain of Methanobacterium thermoautortrophicum

    International Nuclear Information System (INIS)

    Nagle, D.P. Jr.; Teal, R.; Eisenbraun, A.

    1987-01-01

    Growth of Methanobacterium thermoautotrophicum Marburg is inhibited by the pyrimidine, 5-fluorouracil (FU). It was shown previously that methanogenesis is not inhibited to the same extent as growth. A spontaneously occurring FU-resistant strain (RTAE-1) was isolated from a culture of strain Marburg. The growth of both strains was inhibited by 5-fluorodeoxyuridine but not 5-fluorocytosine, and the wild type was more susceptible to inhibition by 5-azauracil and 6-azauracil than was strain RTAE-1. The cellular targets for the pyrimidine analogs are not known. When the accumulation of 14 C-labeled uracil or FU by the two strains was compared, the wilt type took up 15-fold more radiolabel per cell than did the FU-resistant strain. In the wild type, radiolabel from uracil was incorporated into the soluble pool, RNA, and DNA. The metabolism of uracil appeared to involve a uracil phosphoribosyltransferase activity. Strain Marburg extracts contained this enzyme, whereas FU-resistant strain RTAE-1 extracts had less than 1/10 as much activity. Although it is possible that a change in permeability to the compounds plays a role in the stable resistance of strain RTAE-1, the fact that it lacks the ability to metabolize pyrimidines to nucleotides is sufficient to account for its phenotype

  4. Lysophosphatidic acid inhibition of the accumulation of Pseudomonas aeruginosa PAO1 alginate, pyoverdin, elastase and LasA

    DEFF Research Database (Denmark)

    Laux, D.C.; Corson, J.M.; Givskov, Michael Christian

    2002-01-01

    . In the present study, a lysophospholipid, 1-paimitoyl-2-hydroxy-sn-glycero-3-phosphate [also called monopalmitoylphosphatidic acid (MPPA)], which accumulates in inflammatory exudates, was shown to inhibit the extracellular accumulation of P. aeruginosa PAO1 alginate, elastase, LasA protease and the siderophore...

  5. Molecular study of Porcine Circovirus type 2 in wild boars and domestic pigs in Uruguay from 2010 to 2014: Predominance of recombinant circulating strains.

    Science.gov (United States)

    Ramos, Natalia; Porley, Dario; Mirazo, Santiago; Castro, Gustavo; Cabrera, Karina; Lozano, Alejandra; Arbiza, Juan

    2017-12-30

    Porcine Circovirus type 2 (PCV2) is a worldwide distributed pathogen and one of the most economically relevant swine infections. Four genotypes have been recognized and it is well known that PCV2a, PCV2b and PCV2d have a global distribution. However, the information about recombinant strains circulation and their influence in driving PCV2 evolution is a poorly studied area. In Uruguay, PCV2 associated symptoms began to be frequently observed in pigs from different farms since 2010. The main purpose of this study was to thoroughly investigate the molecular epidemiology of PCV2 in nationwide swine herds and free-living wild boars during the period 2010-2014, providing an extensive viral sequence dataset. Surprisingly, the findings revealed a predominance of recombinant strains circulation, evidencing for the first time in the field that PCV2 recombination can lead to the emergence of strains able to compete and potentially displace parental ones. In addition, the circulation of the genotypes PCV2d (29%), PCV2b (10.5%) and PCV2a (7.9%) were also observed. Since 2013, a high circulation of PCV2d was identified in the country and probably reflected the recent global scenario of the emergence of this genotype. In addition, fluctuations in the frequency of PCV2 infection in the period evaluated may suggest a limitation of biosecurity strategies implemented in Uruguay for the disease control, including the instability of vaccination practices. On the other hand, the sustained PCV2 infection observed in wild boar population and the similarity among circulating viral strains from these animals and domestic pigs, suggested that wild animals could serve as permanent reservoir of the disease. Altogether, this work put forward that many factors play a role in PCV2 heterogeneity including rapid viral spread and evolution, recombination, wide movement within national boundaries and multiples introduction events resulting of international trade. Continuous monitoring of viral

  6. Genetic Characterization of the Hemagglutinin Genes of Wild-Type Measles Virus Circulating in China, 1993–2009

    Science.gov (United States)

    Zhu, Zhen; Liu, Chunyu; Mao, Naiying; Ji, Yixin; Wang, Huiling; Jiang, Xiaohong; Li, Chongshan; Tang, Wei; Feng, Daxing; Wang, Changyin; Zheng, Lei; Lei, Yue; Ling, Hua; Zhao, Chunfang; Ma, Yan; He, Jilan; Wang, Yan; Li, Ping; Guan, Ronghui; Zhou, Shujie; Zhou, Jianhui; Wang, Shuang; Zhang, Hong; Zheng, Huanying; Liu, Leng; Ma, Hemuti; Guan, Jing; Lu, Peishan; Feng, Yan; Zhang, Yanjun; Zhou, Shunde; Xiong, Ying; Ba, Zhuoma; Chen, Hui; Yang, Xiuhui; Bo, Fang; Ma, Yujie; Liang, Yong; Lei, Yake; Gu, Suyi; Liu, Wei; Chen, Meng; Featherstone, David; Jee, Youngmee; Bellini, William J.; Rota, Paul A.; Xu, Wenbo

    2013-01-01

    Background China experienced several large measles outbreaks in the past two decades, and a series of enhanced control measures were implemented to achieve the goal of measles elimination. Molecular epidemiologic surveillance of wild-type measles viruses (MeV) provides valuable information about the viral transmission patterns. Since 1993, virologic surveillnace has confirmed that a single endemic genotype H1 viruses have been predominantly circulating in China. A component of molecular surveillance is to monitor the genetic characteristics of the hemagglutinin (H) gene of MeV, the major target for virus neutralizing antibodies. Principal Findings Analysis of the sequences of the complete H gene from 56 representative wild-type MeV strains circulating in China during 1993–2009 showed that the H gene sequences were clustered into 2 groups, cluster 1 and cluster 2. Cluster1 strains were the most frequently detected cluster and had a widespread distribution in China after 2000. The predicted amino acid sequences of the H protein were relatively conserved at most of the functionally significant amino acid positions. However, most of the genotype H1 cluster1 viruses had an amino acid substitution (Ser240Asn), which removed a predicted N-linked glycosylation site. In addition, the substitution of Pro397Leu in the hemagglutinin noose epitope (HNE) was identified in 23 of 56 strains. The evolutionary rate of the H gene of the genotype H1 viruses was estimated to be approximately 0.76×10−3 substitutions per site per year, and the ratio of dN to dS (dN/dS) was measles in China. PMID:24073194

  7. Genetic relatedness of ciprofloxacin-resistant Shigella dysenteriae type 1 strains isolated in south Asia.

    Science.gov (United States)

    Talukder, Kaisar A; Khajanchi, Bijay K; Islam, M Aminul; Dutta, Dilip K; Islam, Zhahirul; Safa, Ashrafus; Khan, G Y; Alam, Khorshed; Hossain, M A; Malla, Sarala; Niyogi, S K; Rahman, Mustafizur; Watanabe, Haruo; Nair, G Balakrish; Sack, David A

    2004-10-01

    The aim of the present study was to determine the clonal relationships of ciprofloxacin-resistant Shigella dysenteriae type 1 strains isolated from south Asia, and S. dysenteriae 1 strains associated with epidemics in 1978, 1984 and 1994. The antimicrobial susceptibilities were examined by NCCLS methods. Molecular epidemiological characterization was performed by plasmid profiling, pulsed-field gel electrophoresis (PFGE) and mutation analysis of the quinolone resistance-determining region (QRDR) of gyrA by sequencing. Plasmid patterns of the current ciprofloxacin-resistant strains from India, Nepal and Bangladesh were very similar to those of the 1978, 1984 and 1994 epidemic isolates of S. dysenteriae 1, except for the presence of a new plasmid of approximately 2.6 MDa, which was found in one recent ciprofloxacin-resistant strain isolated in Bangladesh. PFGE analysis showed that the ciprofloxacin-resistant strains isolated in Bangladesh, India and Nepal belonged to a PFGE type (type A), which was possibly related to that of the 1984 and 1994 clone of S. dysenteriae 1, but different from 1978 epidemic strains. The current ciprofloxacin-resistant strains belong to five subtypes (A3-A7), all of which were found in India, but in Bangladesh and Nepal, only A3 existed. Mutation analysis of the QRDR of gyrA revealed that amino acid substitutions at positions 83 and 87 of ciprofloxacin-resistant strains isolated in Bangladesh were similar to those of the strains isolated in Nepal, but different (at position 87) from ciprofloxacin-resistant strains isolated in India. PFGE and mutation analysis of gyrA showed differences between the current ciprofloxacin-resistant S. dysenteriae 1 strains isolated in south Asia and those associated with epidemics in 1978, 1984 and 1994.

  8. Upgrading the Control Systems of Turbines of K-160-12.8 Type Produced by PAO Turboatom

    Science.gov (United States)

    Babayev, I. N.

    2018-05-01

    Steam turbines of a K-160-12.8 (PVK-150) type produced by PAO Turboatom are operated at thermal power plants from the 1960s and many of them still have the complete set that was installed at that time by the factory, but they have become out of date. For this reason, the problem of upgrading the turbines to bring their characteristics into compliance with modern requirements is relevant. This article describes the main technical decisions adopted by PAO Turboatom when upgrading the automatic control system (ACS) of a K-160-12.8 (PVK-150) turbine: replacing the control valves (CV); replacing the distributing mechanism; replacing the front support components, including the main servomotor and oil control pipes; and replacing the assembly of cutoff spools by separate spools of servomotors of high-pressure control valves and reheat control valves. The schematic diagram of the ACS and description of the structure of newly installed mechanisms are presented: the cutoff spools, the high-pressure CVs, the distribution mechanism, and the main servomotor. The particularity of the ACS is the presence of electromechanical converters, which are used in each cutoff spool. For improving operating reliability of the ACS by providing the actuation of servomotors of control valves for closing regardless of ACS commands, the connection of rods of the electromechanical converter and cutoff spools are made using spring-type uncoupling devices. For actuation of the protection system by the commands of the automatic electronic safety device, the separate actuator driven by an electromagnet is installed in the ACS. During further improvement of the protection system, it is recommended to replace the controller assembly by two-spool protection devices, remove the protection spool assembly, and increase the pressure in the protection lines up to power pressure. The upgrading during this project was carried out by the Dobrotvor TPP (Ukraine).

  9. Identification of Resistance to Wet Bubble Disease and Genetic Diversity in Wild and Cultivated Strains of Agaricus bisporus

    Directory of Open Access Journals (Sweden)

    Yongping Fu

    2016-09-01

    Full Text Available Outbreaks of wet bubble disease (WBD caused by Mycogone perniciosa are increasing across the world and seriously affecting the yield of Agaricus bisporus. However, highly WBD-resistant strains are rare. Here, we tested 28 A. bisporus strains for WBD resistance by inoculating M. perniciosa spore suspension on casing soil, and assessed genetic diversity of these strains using 17 new simple sequence repeat (SSR markers developed in this study. We found that 10 wild strains originating from the Tibetan Plateau in China were highly WBD-resistant strains, and 13 cultivated strains from six countries were highly susceptible strains. A total of 88 alleles were detected in these 28 strains, and the observed number of alleles per locus ranged from 2 to 8. Cluster and genetic structure analysis results revealed the wild resources from China have a relatively high level of genetic diversity and occur at low level of gene flow and introgression with cultivated strains. Moreover, the wild strains from China potentially have the consensus ancestral genotypes different from the cultivated strains and evolved independently. Therefore, the highly WBD-resistant wild strains from China and newly developed SSR markers could be used as novel sources for WBD-resistant breeding and quantitative trait locus (QTL mapping of WBD-resistant gene of A. bisporus.

  10. HM-PAO SPECT in the diagnosis of cerebrovascular disease

    International Nuclear Information System (INIS)

    Cordes, M.; Rummeny, E.; Reissmann, M.; Fox, K.; Panitz, N.; Pfannenstiel, P.

    1987-01-01

    Single photon emission computed tomography (SPECT) after injection of 99m-Tc-HM-PAO was used to examine 34 patients whose clinical findings could not exclude a cerebrovascular disease. In all patients an X-ray computed tomography examination was inconclusive for the clinical-neurological findings. The regional cerebral bloodflow was pathologically disturbed in 10 of 34 patients in the HM-PAO SPECT examination. The detection of the regional cerebral bloodflow with HM-PAO SPECT is helpful in the diagnosis of cerebrovascular disease. (orig.) [de

  11. Genetic diversity and population structure of Iranian wild Pleurotus eryngii species-complex strains revealed by URP-PCR markers

    NARCIS (Netherlands)

    Behnamian, Mahdi; Mohammadi, Seyed A.; Sonnenberg, A.S.M.; Goltapeh, Ebrahim M.; Hendrickx, P.M.

    2010-01-01

    In the present study, a set of 68 P. eryngii wild strains collected from nine locations in northwest and west of Iran along with six commercial strains were studied using universal rice primers (URP). The wild strains were isolated from Ferula ovina, F. haussknechtii, Cachrys ferulacea, Kellusia

  12. CodY Promotes Sporulation and Enterotoxin Production by Clostridium perfringens Type A Strain SM101.

    Science.gov (United States)

    Li, Jihong; Freedman, John C; Evans, Daniel R; McClane, Bruce A

    2017-03-01

    Clostridium perfringens type D strains cause enterotoxemia and enteritis in livestock via epsilon toxin production. In type D strain CN3718, CodY was previously shown to increase the level of epsilon toxin production and repress sporulation. C. perfringens type A strains producing C. perfringens enterotoxin (CPE) cause human food poisoning and antibiotic-associated diarrhea. Sporulation is critical for C. perfringens type A food poisoning since spores contribute to transmission and resistance in the harsh food environment and sporulation is essential for CPE production. Therefore, the current study asked whether CodY also regulates sporulation and CPE production in SM101, a derivative of C. perfringens type A food-poisoning strain NCTC8798. An isogenic codY -null mutant of SM101 showed decreased levels of spore formation, along with lower levels of CPE production. A complemented strain recovered wild-type levels of both sporulation and CPE production. When this result was coupled with the earlier results obtained with CN3718, it became apparent that CodY regulation of sporulation varies among different C. perfringens strains. Results from quantitative reverse transcriptase PCR analysis clearly demonstrated that, during sporulation, codY transcript levels remained high in SM101 but rapidly declined in CN3718. In addition, abrB gene expression patterns varied significantly between codY -null mutants of SM101 and CN3718. Compared to the levels in their wild-type parents, the level of abrB gene expression decreased in the CN3718 codY -null mutant strain but significantly increased in the SM101 codY -null mutant strain, demonstrating CodY-dependent regulation differences in abrB expression between these two strains. This difference appears to be important since overexpression of the abrB gene in SM101 reduced the levels of sporulation and enterotoxin production, supporting the involvement of AbrB repression in regulating C. perfringens sporulation. Copyright © 2017

  13. Antigen-driven C–C Chemokine-mediated HIV-1 Suppression by CD4+ T Cells from Exposed Uninfected Individuals Expressing the Wild-type CCR-5 Allele

    Science.gov (United States)

    Furci, Lucinda; Scarlatti, Gabriella; Burastero, Samuele; Tambussi, Giuseppe; Colognesi, Claudia; Quillent, Caroline; Longhi, Renato; Loverro, Patrizia; Borgonovo, Barbara; Gaffi, Davide; Carrow, Emily; Malnati, Mauro; Lusso, Paolo; Siccardi, Antonio G.; Lazzarin, Adriano; Beretta, Alberto

    1997-01-01

    Despite repeated exposure to HIV-1, certain individuals remain persistently uninfected. Such exposed uninfected (EU) people show evidence of HIV-1–specific T cell immunity and, in rare cases, selective resistance to infection by macrophage-tropic strains of HIV-1. The latter has been associated with a 32–base pair deletion in the C–C chemokine receptor gene CCR-5, the major coreceptor of macrophage-tropic strains of HIV-1. We have undertaken an analysis of the HIV-specific T cell responses in 12 EU individuals who were either homozygous for the wild-type CCR-5 allele or heterozygous for the deletion allele (CCR-5Δ32). We have found evidence of an oligoclonal T cell response mediated by helper T cells specific for a conserved region of the HIV-1 envelope. These cells produce very high levels of C–C chemokines when stimulated by the specific antigen and suppress selectively the replication of macrophage-tropic, but not T cell–tropic, strains of HIV-1. These chemokine-producing helper cells may be part of a protective immune response that could be potentially exploited for vaccine development. PMID:9236198

  14. Role of UV-inducible proteins in repair of various wild-type Escherichia coli cells

    International Nuclear Information System (INIS)

    Sedliakova, M.; Slezarikova, V.; Brozmanova, J.; Masek, F.; Bayerova, V.

    1980-01-01

    3 wild-type strains of E. coli, namely K12 AB2497, B/r WP2 and 15 555-7, proficient in excision and post-replication repair, differ markedly in their UV resistance. To elucidate this difference, the influence was investigated of induction by application of inducing fluence (IF) before lethal fluence (LF) on repair processes after LF. In cells distinguished by low UV resistance (E. coli 15 555-7; E. coli B/r WP2), dimer excision was less complete in cultures irradiated with IF + LF than in cultures irradiated with LF only. The highly resistant E. coli K12 AB2497 performed complete excision both after IF + LF or after LF alone. All 3 types of cell survived better after IF + LF than after LF only. Because, in most strains so far investigated, the application of IF reduced dimer excision and increased survival, dimer excision per se does not appear important for survival. We conclude that the rate and completeness of dimer excision can serve as a measure of efficiency of the excision system whose action is necessary for repair of another lesion. Cells of all investigated strains could not resume DNA replication and died progressively when irradiated with LF and post-incubated with chloramphenicol (LF CAP + ). Thus, it appears that inducible proteins are necessary for repair in all wild-type E. coli cells given with potentially lethal doses of UV irradiation. (orig.)

  15. Lysogenic Streptococcus suis isolate SS2-4 containing prophage SMP showed increased mortality in zebra fish compared to the wild-type isolate.

    Directory of Open Access Journals (Sweden)

    Fang Tang

    Full Text Available Streptococcus suis (S. suis infection is considered to be a major problem in the swine industry worldwide. Based on the capsular type, 33 serotypes of S. suis have been described, with serotype 2 (SS2 being the most frequently isolated from diseased piglets. Little is known, however, about the pathogenesis and virulence factors of S. suis. Research on bacteriophages highlights a new area in S. suis research. A S. suis serotype 2 bacteriophage, designated SMP, has been previously isolated in our laboratory. Here, we selected a lysogenic isolate in which the SMP phage was integrated into the chromosome of strain SS2-4. Compared to the wild-type isolate, the lysogenic strain showed increased mortality in zebra fish. Moreover the sensitivity of the lysogenic strain to lysozyme was seven times higher than that of the wild-type.

  16. No postnatal maternal effect on male aggressiveness in wild-derived strains of house mice

    Czech Academy of Sciences Publication Activity Database

    Ďureje, Ľudovít; Vošlajerová Bímová, Barbora; Piálek, Jaroslav

    2011-01-01

    Roč. 37, č. 1 (2011), s. 48-55 ISSN 0096-140X R&D Projects: GA AV ČR KJB600930701 Institutional research plan: CEZ:AV0Z60930519 Keywords : aggression * cross-fostering * wild-derived inbred strains * house mouse Subject RIV: EG - Zoology Impact factor: 2.630, year: 2011

  17. Comparative biology and reproductive behaviour of a laboratory-adapted Redco strain of Anopheles Gambiae Giles (Diptera; culicidae and wild populations of the same species

    International Nuclear Information System (INIS)

    Barfi, E.

    2015-07-01

    The sterile insect technique involves mass rearing of male insects for sterility purpose. This heavily relies on male fitness and genetic compatibility of laboratory-adapted male insects and the wild to ensure successful competition with their male counterpart in the wild. Uniform environment in the laboratory as compared to the wild conditions might lead to genetic drift which might lead to reduced sexual competitiveness, fitness, morphological changes or changes in the sexual behaviour of mosquitoes. This work investigated the sexual compatibility, morphometry and sexual behaviour of laboratory-adapted strain and wild strain of Anopheles gambiae under laboratory conditions. These measurements were done by observing swarm formation, genitalia rotation, percentage insemination, fecundity, fertility, wing length, wing width, thoracic width, body length, body size index and wing size index. Morphometric studies of laboratory-adapted and wild strain of Anopheles gambiae were carried out by observing the wing length, body length and thoracic length under Lecia 4D stereoscope in order to find out variations in the body size between the two strains. The results showed significant difference between thoracic width and wing length between the laboratory-adapted strain and wild strain. Indices such as body size index and wing length index also showed significant difference between the two strains; laboratory-adapted REDCO strain (BSI 4.45 ± 0.10, p = 0.010 ; WSI 1.92 ± 0.07, p = 0.026) and wild REDCO strain ( 4.08 ± 0.10, p = 0.010 ; WSI 1.73 ± 0.04, p = 0.026 ). Body length of laboratory-adapted male mosquitoes (4.24 ± 0.05, p = 0.462) was not significantly different from its thoracic width, wing length, and wing width. The wild strain on the other hand had significant difference between its body length (4.19 ± 0.04, p = 0.462), thoracic width (0.096 ± 0.02, p = 0.002 ) and wing length (2.99 ± 0.03, p = 0.050 ). In the mating experiment, egg production in each of

  18. Characterization of two second-site mutations preventing wild type protein aggregation caused by a dominant negative PMA1 mutant.

    Directory of Open Access Journals (Sweden)

    Pilar Eraso

    Full Text Available The correct biogenesis and localization of Pma1 at the plasma membrane is essential for yeast growth. A subset of PMA1 mutations behave as dominant negative because they produce aberrantly folded proteins that form protein aggregates, which in turn provoke the aggregation of the wild type protein. One approach to understand this dominant negative effect is to identify second-site mutations able to suppress the dominant lethal phenotype caused by those mutant alleles. We isolated and characterized two intragenic second-site suppressors of the PMA1-D378T dominant negative mutation. We present here the analysis of these new mutations that are located along the amino-terminal half of the protein and include a missense mutation, L151F, and an in-frame 12bp deletion that eliminates four residues from Cys409 to Ala412. The results show that the suppressor mutations disrupt the interaction between the mutant and wild type enzymes, and this enables the wild type Pma1 to reach the plasma membrane.

  19. The Sinbad retrotransposon from the genome of the human blood fluke, Schistosoma mansoni, and the distribution of related Pao-like elements

    Directory of Open Access Journals (Sweden)

    Morales Maria E

    2005-02-01

    Full Text Available Abstract Background Of the major families of long terminal repeat (LTR retrotransposons, the Pao/BEL family is probably the least well studied. It is becoming apparent that numerous LTR retrotransposons and other mobile genetic elements have colonized the genome of the human blood fluke, Schistosoma mansoni. Results A proviral form of Sinbad, a new LTR retrotransposon, was identified in the genome of S. mansoni. Phylogenetic analysis indicated that Sinbad belongs to one of five discreet subfamilies of Pao/BEL like elements. BLAST searches of whole genomes and EST databases indicated that members of this clade occurred in species of the Insecta, Nematoda, Echinodermata and Chordata, as well as Platyhelminthes, but were absent from all plants, fungi and lower eukaryotes examined. Among the deuterostomes examined, only aquatic species harbored these types of elements. All four species of nematode examined were positive for Sinbad sequences, although among insect and vertebrate genomes, some were positive and some negative. The full length, consensus Sinbad retrotransposon was 6,287 bp long and was flanked at its 5'- and 3'-ends by identical LTRs of 386 bp. Sinbad displayed a triple Cys-His RNA binding motif characteristic of Gag of Pao/BEL-like elements, followed by the enzymatic domains of protease, reverse transcriptase (RT, RNAseH, and integrase, in that order. A phylogenetic tree of deduced RT sequences from 26 elements revealed that Sinbad was most closely related to an unnamed element from the zebrafish Danio rerio and to Saci-1, also from S. mansoni. It was also closely related to Pao from Bombyx mori and to Ninja of Drosophila simulans. Sinbad was only distantly related to the other schistosome LTR retrotransposons Boudicca, Gulliver, Saci-2, Saci-3, and Fugitive, which are gypsy-like. Southern hybridization and bioinformatics analyses indicated that there were about 50 copies of Sinbad in the S. mansoni genome. The presence of ESTs

  20. Whole exome sequencing of wild-derived inbred strains of mice improves power to link phenotype and genotype.

    Science.gov (United States)

    Chang, Peter L; Kopania, Emily; Keeble, Sara; Sarver, Brice A J; Larson, Erica; Orth, Annie; Belkhir, Khalid; Boursot, Pierre; Bonhomme, François; Good, Jeffrey M; Dean, Matthew D

    2017-10-01

    The house mouse is a powerful model to dissect the genetic basis of phenotypic variation, and serves as a model to study human diseases. Despite a wealth of discoveries, most classical laboratory strains have captured only a small fraction of genetic variation known to segregate in their wild progenitors, and existing strains are often related to each other in complex ways. Inbred strains of mice independently derived from natural populations have the potential to increase power in genetic studies with the addition of novel genetic variation. Here, we perform exome-enrichment and high-throughput sequencing (~8× coverage) of 26 wild-derived strains known in the mouse research community as the "Montpellier strains." We identified 1.46 million SNPs in our dataset, approximately 19% of which have not been detected from other inbred strains. This novel genetic variation is expected to contribute to phenotypic variation, as they include 18,496 nonsynonymous variants and 262 early stop codons. Simulations demonstrate that the higher density of genetic variation in the Montpellier strains provides increased power for quantitative genetic studies. Inasmuch as the power to connect genotype to phenotype depends on genetic variation, it is important to incorporate these additional genetic strains into future research programs.

  1. Use of technetium-99m-HM-PAO in the assessment of patients with dementia and other neuropsychiatric conditions

    International Nuclear Information System (INIS)

    Smith, F.W.; Besson, J.A.; Gemmell, H.G.; Sharp, P.F.

    1988-01-01

    One hundred fourteen patients suffering from neuropsychiatric conditions have been studied using 99mTc-labeled hexamethylpropyleneamine oxime (HM-PAO) and single photon emission computed tomography (SPECT). Ninety-one patients had a firm clinical diagnosis while 23 were examined without knowledge of the clinical diagnosis. Of the 91 patients, 51 were suffering from dementia, 25 multi-infarct type and 26 Alzheimer's disease. In 19 of the Alzheimer's patients, a characteristic pattern of decreased perfusion in the parieto-occipital regions was demonstrated while those with multi-infarct type showed varying degrees of irregular uptake in the cerebral cortex. These appearances are similar to those shown with positron emission tomography (PET) and we believe that HM-PAO will provide a widely available method for identifying patients with Alzheimer's disease. Twenty-nine patients were suffering from diseases involving the basal ganglia. Fifteen patients with Parkinson's disease showed no significant abnormality in basal ganglia uptake, while 7 or 8 patients with Huntington's disease who had full examinations showed decreased uptake in the caudate nuclei. Similarly, four of six patients with other basal ganglia diseases showed impaired uptake by basal ganglia, and it is concluded that HM-PAO may be useful for the diagnosis and management of this type of patient. Twenty-three patients received HM-PAO imaging as part of their diagnostic work-up; in 19 of them, detailed follow-up was obtained, which indicated that in 7 cases the result of the HM-PAO scan altered the clinical diagnosis and in 9 cases resulted in a change in management. In the remaining 13 cases, the study was found to be helpful in confirming the diagnosis

  2. Type 1 fimbrial expression enhances Escherichia coli virulence for the urinary tract

    DEFF Research Database (Denmark)

    Connell, Hugh; Agace, William; Klemm, Per

    1996-01-01

    of Escherichia coli for the urinary tract by promoting bacterial persistence and enhancing the inflammatory responce to infection. In a clinical study, we observed that disease severity was greater in children infected with E. coli O1:K1:H7 isolates expressing type 1 fimbriae than in those infected with type 1...... negative isolates of the same serotype. The E. coli O1:K1:H7 isolates had the same electrophoretic type, were hemolysin-negative, expressed P fimbriae, and carried the fim DNA sequences. When tested in a mouse urinary tract infection model, the type 1-positive E. coli O1:K1:H7 isolates survived inhigher...... urinary tract infection model. E. coli CN1016 reconstituted with type 1 fimbriae had restored virulence similar to that of the wild-type parent strain. These results show that type 1 fimbriae in the genetic background of a uropathogenic strain contribute to the pathogenesis of E. coli in the urinary tract....

  3. MT-PCR panel detection of canine parvovirus (CPV-2): Vaccine and wild-type CPV-2 can be difficult to differentiate in canine diagnostic fecal samples.

    Science.gov (United States)

    Meggiolaro, Maira N; Ly, Anna; Rysnik-Steck, Benjamin; Silva, Carolina; Zhang, Joshua; Higgins, Damien P; Muscatello, Gary; Norris, Jacqueline M; Krockenberger, Mark; Šlapeta, Jan

    2017-06-01

    Canine parvovirus (CPV-2) remains an important cause of devastating enteritis in young dogs. It can be successfully prevented with live attenuated CPV-2 vaccines when given at the appropriate age and in the absence of maternal antibody interference. Rapid diagnosis of parvoviral enteritis in young dogs is essential to ensuring suitable barrier nursing protocols within veterinary hospitals. The current diagnostic trend is to use multiplexed PCR panels to detect an array of pathogens commonly responsible for diarrhea in dogs. The multiplexed PCR assays do not distinguish wild from vaccine CPV-2. They are highly sensitive and detect even a low level of virus shedding, such as those caused by the CPV-2 vaccine. The aim of this study was to identify the CPV-2 subtypes detected in diagnostic specimens and rule out occult shedding of CPV-2 vaccine strains. For a total of 21 samples that tested positive for CPV-2 in a small animal fecal pathogens diagnostic multiplexed tandem PCR (MT-PCR) panel during 2014-2016 we partially characterized the VP2 gene of CPV-2. Vaccine CPV-2 strain, wild type CPV-2a subtypes and vaccine-like CPV-2b subtypes were detected. High copy number was indicative of wild-type CPV-2a presence, but presence of vaccine-like CPV-2b had a variable copy number in fecal samples. A yardstick approach to a copy number or C t -value to discriminate vaccine strain from a wild type virus of CPV-2 can be, in some cases, potentially misleading. Therefore, discriminating vaccine strain from a wild type subtype of CPV-2 remains ambitious. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Interaction of Wild Strains of Aspergilla with Aspergillus parasiticus ATCC15517 and Aflatoxin Production †

    Science.gov (United States)

    Martins, H. Marina; Almeida, Inês; Marques, Marta; Bernardo, Fernando

    2008-01-01

    Aflatoxins are secondary metabolites produced by some competent mould strains of Aspergillus flavus, A. parasiticus and A. nomius. These compounds have been extensively studied with regards to their toxicity for animals and humans; they are able to induce liver cancer and may cause a wide range of adverse effects in living organisms. Aflatoxins are found as natural contaminants of food and feed; the main line of the strategy to control them is based on the prevention of the mould growth in raw vegetable or during its storage and monitoring of each crop batch. Mould growth is conditioned by many ecological factors, including biotic ones. Hazard characterization models for aflatoxins in crops must take into consideration biotic interactions between moulds and their potential effects on growth development. The aim of this work is to study the effect of the biotic interaction of 14 different wild strains of Aspergilla (different species), with a competent strain (Aspergillus parasiticus ATCC 15517) using an in vitro production model. The laboratory model used was a natural matrix (humidified cracked corn), on which each wild strain challenged the aflatoxin production of a producer strain. Cultures were incubated at 28°C for 12 days and sampled at the 8th and 12th. Aflatoxin detection and quantification was performed by HPLC using a procedure with a MRPL = 1 μg/kg. Results of those interactive cultures revealed both synergic and antagonistic effects on aflatoxin biosynthesis. Productivity increases were particularly evident on the 8th day of incubation with wild strains of A. flavipes (+ 70.4 %), A. versicolor (+ 54.9 %) and A. flavus 3 (+ 62.6 %). Antagonistic effects were found with A. niger (− 69.5%), A. fumigatus (− 47.6 %) and A. terreus (− 47.6 %) on the 12th day. The increased effects were more evident on the 8th of incubation and the decreases were more patent on the 12th day. Results show that the development of Aspergilla strains concomitantly with

  5. Differential infection properties of three inducible prophages from an epidemic strain of Pseudomonas aeruginosa

    Directory of Open Access Journals (Sweden)

    James Chloe E

    2012-09-01

    Full Text Available Abstract Background Pseudomonas aeruginosa is the most common bacterial pathogen infecting the lungs of patients with cystic fibrosis (CF. The Liverpool Epidemic Strain (LES is transmissible, capable of superseding other P. aeruginosa populations and is associated with increased morbidity. Previously, multiple inducible prophages have been found to coexist in the LES chromosome and to constitute a major component of the accessory genome not found in other sequenced P. aerugionosa strains. LES phages confer a competitive advantage in a rat model of chronic lung infection and may, therefore underpin LES prevalence. Here the infective properties of three LES phages were characterised. Results This study focuses on three of the five active prophages (LESφ2, LESφ3 and LESφ4 that are members of the Siphoviridae. All were induced from LESB58 by norfloxacin. Lytic production of LESφ2 was considerably higher than that of LESφ3 and LESφ4. Each phage was capable of both lytic and lysogenic infection of the susceptible P. aeruginosa host, PAO1, producing phage-specific plaque morphologies. In the PAO1 host background, the LESφ2 prophage conferred immunity against LESφ3 infection and reduced susceptibility to LESφ4 infection. Each prophage was less stable in the PAO1 chromosome with substantially higher rates of spontaneous phage production than when residing in the native LESB58 host. We show that LES phages are capable of horizontal gene transfer by infecting P. aeruginosa strains from different sources and that type IV pili are required for infection by all three phages. Conclusions Multiple inducible prophages with diverse infection properties have been maintained in the LES genome. Our data suggest that LESφ2 is more sensitive to induction into the lytic cycle or has a more efficient replicative cycle than the other LES phages.

  6. Annotating and quantifying pri-miRNA transcripts using RNA-Seq data of wild type and serrate-1 globular stage embryos of Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Daniel Lepe-Soltero

    2017-12-01

    Full Text Available The genome annotation for the model plant Arabidopsis thaliana does not include the primary transcripts from which MIRNAs are processed. Here we present and analyze the raw mRNA sequencing data from wild type and serrate-1 globular stage embryos of A. thaliana, ecotype Columbia. Because SERRATE is required for pri-miRNA processing, these precursors accumulate in serrate-1 mutants, facilitating their detection using standard RNA-Seq protocols. We first use the mapping of the RNA-Seq reads to the reference genome to annotate the potential primary transcripts of MIRNAs expressed in the embryo. We then quantify these pri-miRNAs in wild type and serrate-1 mutants. Finally, we use differential expression analysis to determine which are up-regulated in serrate-1 compared to wild type, to select the best candidates for bona fide pri-miRNAs expressed in the globular stage embryos. In addition, we analyze a previously published RNA-Seq dataset of wild type and dicer-like 1 mutant embryos at the globular stage [1]. Our data are interpreted and discussed in a separate article [2].

  7. Annotating and quantifying pri-miRNA transcripts using RNA-Seq data of wild type and serrate-1 globular stage embryos of Arabidopsis thaliana.

    Science.gov (United States)

    Lepe-Soltero, Daniel; Armenta-Medina, Alma; Xiang, Daoquan; Datla, Raju; Gillmor, C Stewart; Abreu-Goodger, Cei

    2017-12-01

    The genome annotation for the model plant Arabidopsis thaliana does not include the primary transcripts from which MIRNAs are processed. Here we present and analyze the raw mRNA sequencing data from wild type and serrate-1 globular stage embryos of A. thaliana , ecotype Columbia. Because SERRATE is required for pri-miRNA processing, these precursors accumulate in serrate-1 mutants, facilitating their detection using standard RNA-Seq protocols. We first use the mapping of the RNA-Seq reads to the reference genome to annotate the potential primary transcripts of MIRNAs expressed in the embryo. We then quantify these pri-miRNAs in wild type and serrate-1 mutants. Finally, we use differential expression analysis to determine which are up-regulated in serrate-1 compared to wild type, to select the best candidates for bona fide pri-miRNAs expressed in the globular stage embryos. In addition, we analyze a previously published RNA-Seq dataset of wild type and dicer-like 1 mutant embryos at the globular stage [1]. Our data are interpreted and discussed in a separate article [2].

  8. Expression of a Synthetic Gene for the Major Cytotoxin (Cyt1Aa of Bacillus thuringiensis subsp. israelensis in the Chloroplast of Wild-Type Chlamydomonas

    Directory of Open Access Journals (Sweden)

    Seongjoon Kang

    2018-05-01

    Full Text Available Chlamydomonas reinhardtii (Chlamydomonas strains that are toxic to mosquito larvae because they express chloroplast transgenes that are based on the mosquitocidal proteins of Bacillus thuringiensis subsp. israelensis (Bti could be very useful in mosquito control. Chlamydomonas has several advantages for this approach, including genetic controls not generally available with industrial algae. The Bti toxin is produced by sporulating bacteria and has been used for mosquito control for >30 years without creating highly resistant mosquito populations. The suite of toxins is four main proteins: three Cry proteins and the cytotoxic Cyt1Aa (27 kDa. Cyt1Aa is not very toxic to mosquitoes by itself, but it prevents the development of resistance. The production of Cyt1Aa in other microbes, however, has been challenging due to its affinity for certain membrane phospholipids. Here we report on the production of recombinant Cyt1Aa (rCyt1A in the chloroplast of photosynthetic Chlamydomonas at levels of at least 0.3% total protein. Live cell bioassays demonstrated toxicity of the rCyt1Aa Chlamydomonas to larvae of Aedes aegypti. We also expressed the chloroplast cyt1Aa gene in a wild-type Chlamydomonas strain (21 gr that can grow on nitrate. These results have implications for developing a Chlamydomonas strain that will be toxic to mosquito larvae but will not induce strongly resistant populations.

  9. Inherited differences in crossing over and gene conversion frequencies between wild strains of Sordaria fimicola from "Evolution Canyon".

    Science.gov (United States)

    Saleem, M; Lamb, B C; Nevo, E

    2001-12-01

    Recombination generates new combinations of existing genetic variation and therefore may be important in adaptation and evolution. We investigated whether there was natural genetic variation for recombination frequencies and whether any such variation was environment related and possibly adaptive. Crossing over and gene conversion frequencies often differed significantly in a consistent direction between wild strains of the fungus Sordaria fimicola isolated from a harsher or a milder microscale environment in "Evolution Canyon," Israel. First- and second-generation descendants from selfing the original strains from the harsher, more variable, south-facing slope had higher frequencies of crossing over in locus-centromere intervals and of gene conversion than those from the lusher north-facing slopes. There were some significant differences between strains within slopes, but these were less marked than between slopes. Such inherited variation could provide a basis for natural selection for optimum recombination frequencies in each environment. There were no significant differences in meiotic hybrid DNA correction frequencies between strains from the different slopes. The conversion analysis was made using only conversions to wild type, because estimations of conversion to mutant were affected by a high frequency of spontaneous mutation. There was no polarized segregation of chromosomes at meiosis I or of chromatids at meiosis II.

  10. Wild-type MIC distributions of four fluoroquinolones active against Mycobacterium tuberculosis in relation to current critical concentrations and available pharmacokinetic and pharmacodynamic data.

    Science.gov (United States)

    Angeby, K A; Jureen, P; Giske, C G; Chryssanthou, E; Sturegård, E; Nordvall, M; Johansson, A G; Werngren, J; Kahlmeter, G; Hoffner, S E; Schön, T

    2010-05-01

    To describe wild-type distributions of the MIC of fluoroquinolones for Mycobacterium tuberculosis in relation to current critical concentrations used for drug susceptibility testing and pharmacokinetic/pharmacodynamic (PK/PD) data. A 96-stick replicator on Middlebrook 7H10 medium was used to define the MICs of ciprofloxacin, ofloxacin, moxifloxacin and levofloxacin for 90 consecutive clinical strains and 24 drug-resistant strains. The MICs were compared with routine BACTEC 460 susceptibility results and with MIC determinations in the BACTEC MGIT 960 system in a subset of strains using ofloxacin as a class representative. PK/PD data for each drug were reviewed in relation to the wild-type MIC distribution. The wild-type MICs of ciprofloxacin, ofloxacin, moxifloxacin and levofloxacin were distributed from 0.125 to 1, 0.25 to 1, 0.032 to 0.5 and 0.125 to 0.5 mg/L, respectively. The MIC data correlated well with the BACTEC 960 MGIT and BACTEC 460 results. PD indices were the most favourable for levofloxacin, followed by moxifloxacin, ofloxacin and ciprofloxacin. We propose S (susceptible) 1.0 mg/L as the tentative epidemiological cut-off (ECOFF) for ofloxacin and ciprofloxacin, and S

  11. Strain specific variation of outer membrane proteins of wild Yersinia pestis strains subjected to different growth temperatures

    Directory of Open Access Journals (Sweden)

    Frederico Guilherme Coutinho Abath

    1990-03-01

    Full Text Available Three Yersinia pestis strains isolated from humans and one laboratory strain (EV76 were grown in rich media at 28§C and 37§C and their outer membrane protein composition compared by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-Page. Several proteins with molecular weights ranging from 34 kDa to 7 kDa were observed to change in relative abundance in samples grown at different temperatures. At least seven Y. pestis outer membrane proteins showed a temperature-dependent and strain-specific behaviour. Some differences between the outer membrane proteins of full-pathogenic wild isolates and the EV76 strain could aldso be detected and the relevance of this finding on the use of laboratory strains as a reference to the study of Y. pestis biological properties is discuted.

  12. Pathological Roles of Wild-Type Cu, Zn-Superoxide Dismutase in Amyotrophic Lateral Sclerosis

    Directory of Open Access Journals (Sweden)

    Yoshiaki Furukawa

    2012-01-01

    Full Text Available Dominant mutations in a Cu, Zn-superoxide dismutase (SOD1 gene cause a familial form of amyotrophic lateral sclerosis (ALS. While it remains controversial how SOD1 mutations lead to onset and progression of the disease, many in vitro and in vivo studies have supported a gain-of-toxicity mechanism where pathogenic mutations contribute to destabilizing a native structure of SOD1 and thus facilitate misfolding and aggregation. Indeed, abnormal accumulation of SOD1-positive inclusions in spinal motor neurons is a pathological hallmark in SOD1-related familial ALS. Furthermore, similarities in clinical phenotypes and neuropathology of ALS cases with and without mutations in sod1 gene have implied a disease mechanism involving SOD1 common to all ALS cases. Although pathogenic roles of wild-type SOD1 in sporadic ALS remain controversial, recent developments of novel SOD1 antibodies have made it possible to characterize wild-type SOD1 under pathological conditions of ALS. Here, I have briefly reviewed recent progress on biochemical and immunohistochemical characterization of wild-type SOD1 in sporadic ALS cases and discussed possible involvement of wild-type SOD1 in a pathomechanism of ALS.

  13. Influence of nutritional and physicochemical variables on PHB production from raw glycerol obtained from a Colombian biodiesel plant by a wild-type Bacillus megaterium strain.

    Science.gov (United States)

    Moreno, Paalo; Yañez, Camilo; Cardozo, Nilo Sérgio Medeiros; Escalante, Humberto; Combariza, Marianny Y; Guzman, Carolina

    2015-12-25

    Biodegradable polymers are currently viable alternatives to traditional synthetic polymers. For instance, polyhydroxybutyrate (PHB) is intracellularly produced and accumulated by Bacillus species, among others. This study reports several wild-type Bacillus strains with the ability to accumulate PHB using raw glycerol from biodiesel production as the sole carbon source. Out of 15 strains from different sources, B. megaterium B2 was selected as the most promising strain for further statistical optimization of the medium composition. Plackett-Burman and central composite designs were used to establish key variables and optimal culture conditions for PHB production using both 250-mL shake flasks and a 7.5-L bioreactor. Temperature and concentrations of glycerol and Na2HPO4 are the experimental variables with the most significant influence on PHB production by B2. After 14 hours of fermentation in shake flasks with optimized medium, B2 produced 0.43 g/L of PHB with a 34% accumulation in the cells. In contrast, under the same conditions, a maximum PHB concentration of 1.20 g/L in the bioreactor was reached at 11 hours. These values correspond to a 48% and 314% increase in PHB production compared to the initial culture conditions. These results suggest the potential of B2 as a PHB producer using raw glycerol, which is an inexpensive, abundant and readily available carbon source. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. CBF tomograms with [/sup 99m/Tc-HM-PAO in patients with dementia (Alzheimer type and HIV) and Parkinson's disease--initial results

    International Nuclear Information System (INIS)

    Costa, D.C.; Ell, P.J.; Burns, A.; Philpot, M.; Levy, R.

    1988-01-01

    We present preliminary data on the utility of functional brain imaging with [99mTc]-d,l-HM-PAO and single photon emission computed tomography (SPECT) in the study of patients with dementia of the Alzheimer type (DAT), HIV-related dementia syndrome, and the on-off syndrome of Parkinson's disease. In comparison with a group of age-matched controls, the DAT patients revealed distinctive bilateral temporal and posterior parietal deficits, which correlate with detailed psychometric evaluation. Patients with amnesia as the main symptom (group A) showed bilateral mesial temporal lobe perfusion deficits (p less than 0.02). More severely affected patients (group B) with significant apraxia, aphasia, or agnosia exhibited patterns compatible with bilateral reduced perfusion in the posterior parietal cortex, as well as reduced perfusion to both temporal lobes, different from the patients of the control group (p less than 0.05). SPECT studies of HIV patients with no evidence of intracraneal space occupying pathology showed marked perfusion deficits. Patients with Parkinson's disease and the on-off syndrome studied during an on phase (under levodopa therapy) and on another occasion after withdrawal of levodopa (off) demonstrated a significant change in the uptake of [99mTc]-d,l-HM-PAO in the caudate nucleus (lower on off) and thalamus (higher on off). These findings justify the present interest in the functional evaluation of the brain of patients with dementia. [99mTc]-d,l-HM-PAO and regional cerebral blood flow (rCBF)/SPECT appear useful and highlight individual disorders of flow in a variety of neuropsychiatric conditions

  15. Strain improvement and metabolic flux analysis in the wild-type and a mutant Lactobacillus lactis strain for L(+)-lactic acid production.

    Science.gov (United States)

    Bai, Dong-Mei; Zhao, Xue-Ming; Li, Xin-Gang; Xu, Shi-Min

    2004-12-20

    The effects of initial glucose concentration and calcium lactate concentration on the lactic acid production by the parent strain, Lactobacillus lactis BME5-18, were studied. The results of the experiments indicated that glucose and lactate repressed the cell growth and the lactic acid production by Lactobacillus lactis BME5-18. A L(+)-lactic acid overproducing strain, Lactobacillus lactis BME5-18M, was screened by mutagenizing the parent strain with ultraviolet (UV) light irradiation and selecting the high glucose and lactate calcium concentration repression resistant mutant. Starting with a concentration of 100g L(-1) glucose, the mutant produced 98.6 g L(-1) lactic acid after 60 h in flasks, 73.9% higher than that of the parent strain. The L(+)-lactic acid purity was 98.1% by weight based on the amount of total lactic acid. The culture of the parent strain could not be analyzed well by conventional metabolic flux analysis techniques, since some pyruvate were accumulated intracellularly. Therefore, a revised flux analysis method was proposed by introducing intracellular pyruvate pool. Further studies demonstrate that there is a high level of NADH oxidase activity (12.11 mmol mg(-1) min(-1)) in the parent strain. The molecular mechanisms of the strain improvement were proposed, i.e., the high level of NADH oxidase activity was eliminated and the uptake rate of glucose was increased from 82.1 C-mmol (g DW h)(-1) to 98.9 C-mmol (g DW h)(-1) by mutagenizing the parent strain with UV, and therefore the mutant strain converts mostly pyruvate to lactic acid with a higher productivity (1.76 g L(-1) h(-1)) than the parent strain (0.95 g L(-1) h(-1)).

  16. Natural type 3/type 2 intertypic vaccine-related poliovirus recombinants with the first crossover sites within the VP1 capsid coding region.

    Science.gov (United States)

    Zhang, Yong; Zhu, Shuangli; Yan, Dongmei; Liu, Guiyan; Bai, Ruyin; Wang, Dongyan; Chen, Li; Zhu, Hui; An, Hongqiu; Kew, Olen; Xu, Wenbo

    2010-12-21

    Ten uncommon natural type 3/type 2 intertypic poliovirus recombinants were isolated from stool specimens from nine acute flaccid paralysis case patients and one healthy vaccinee in China from 2001 to 2008. Complete genomic sequences revealed their vaccine-related genomic features and showed that their first crossover sites were randomly distributed in the 3' end of the VP1 coding region. The length of donor Sabin 2 sequences ranged from 55 to 136 nucleotides, which is the longest donor sequence reported in the literature for this type of poliovirus recombination. The recombination resulted in the introduction of Sabin 2 neutralizing antigenic site 3a (NAg3a) into a Sabin 3 genomic background in the VP1 coding region, which may have been altered by some of the type 3-specific antigenic properties, but had not acquired any type 2-specific characterizations. NAg3a of the Sabin 3 strain seems atypical; other wild-type poliovirus isolates that have circulated in recent years have sequences of NAg3a more like the Sabin 2 strain. 10 natural type 3/type 2 intertypic VP1 capsid-recombinant polioviruses, in which the first crossover sites were found to be in the VP1 coding region, were isolated and characterized. In spite of the complete replacement of NAg3a by type 2-specific amino acids, the serotypes of the recombinants were not altered, and they were totally neutralized by polyclonal type 3 antisera but not at all by type 2 antisera. It is possible that recent type 3 wild poliovirus isolates may be a recombinant having NAg3a sequences derived from another strain during between 1967 and 1980, and the type 3/type 2 recombination events in the 3' end of the VP1 coding region may result in a higher fitness.

  17. Natural type 3/type 2 intertypic vaccine-related poliovirus recombinants with the first crossover sites within the VP1 capsid coding region.

    Directory of Open Access Journals (Sweden)

    Yong Zhang

    Full Text Available BACKGROUND: Ten uncommon natural type 3/type 2 intertypic poliovirus recombinants were isolated from stool specimens from nine acute flaccid paralysis case patients and one healthy vaccinee in China from 2001 to 2008. PRINCIPAL FINDINGS: Complete genomic sequences revealed their vaccine-related genomic features and showed that their first crossover sites were randomly distributed in the 3' end of the VP1 coding region. The length of donor Sabin 2 sequences ranged from 55 to 136 nucleotides, which is the longest donor sequence reported in the literature for this type of poliovirus recombination. The recombination resulted in the introduction of Sabin 2 neutralizing antigenic site 3a (NAg3a into a Sabin 3 genomic background in the VP1 coding region, which may have been altered by some of the type 3-specific antigenic properties, but had not acquired any type 2-specific characterizations. NAg3a of the Sabin 3 strain seems atypical; other wild-type poliovirus isolates that have circulated in recent years have sequences of NAg3a more like the Sabin 2 strain. CONCLUSIONS: 10 natural type 3/type 2 intertypic VP1 capsid-recombinant polioviruses, in which the first crossover sites were found to be in the VP1 coding region, were isolated and characterized. In spite of the complete replacement of NAg3a by type 2-specific amino acids, the serotypes of the recombinants were not altered, and they were totally neutralized by polyclonal type 3 antisera but not at all by type 2 antisera. It is possible that recent type 3 wild poliovirus isolates may be a recombinant having NAg3a sequences derived from another strain during between 1967 and 1980, and the type 3/type 2 recombination events in the 3' end of the VP1 coding region may result in a higher fitness.

  18. Effects of quorum sensing system lasR/rhlR gene on the expression of Foxp3, TGF-β1 and IL-10 of lung tissue in tracheal intubation model rat with Pseudomonas aeruginosa biofilm infection

    Directory of Open Access Journals (Sweden)

    Qing-qing XIANG

    2016-03-01

    Full Text Available Objective  To investigate the effects of lasR/rhlR gene on Foxp3, TGF-β1 and IL-10 of lung tissue in rat tracheal intubation model with biofilm infection of Pseudomonas aeruginosa (Ps. aer wild strain (PAO1 and quorum sensing (QS deficient strain (ΔlasRΔrhlR. Methods  Twenty-one SD rats were randomly assigned into 3 groups (7 each: ΔlasRΔrhlR-treated group, PAO1-treated group and sterile control group. Biofilms (BF were cultured in vitro, and the BF coated tube (infected respectively with Ps. aer PAO1 strain, ΔlasRΔrhlR strain, or with asepsis was inserted into the trachea to establish the rat model. The rats were sacrificed on the 7th day after intubation. Colony count of lung tissue homogenate (cfu and lung HE staining were performed, and IL-10 content in bronchoalveolar lavage fluid (BALF, TGF-β1 in lung tissue, and the expression of Foxp3 mRNA in lung cells were determined. Results  The bacterial counts were significantly higher in PAO1 and ΔlasRΔrhlR groups than that in sterile control group, and the counts were obviously higher in PAO1 group (10 400.00±6313.70/g lung tissue than that in ΔlasRΔrhlR group (975.00±559.97/g lung tissue, P<0.05. There was no significant pathological changes in lung tissue in sterile control group, while the bronchi and blood vessels in PAO1 group were infiltrated by a large number of inflammatory cells and complicated with alveolar septum thickening and local abscess and necrosis. The pathological changes were milder in ΔlasRΔrhlR group than in PAO1 group; the expression of Foxp3 mRNA was higher in the two Ps. aer infected groups than that in sterile control group (0.65±0.32, and it was significantly higher in PAO1 group (4.62±1.07 than in ΔlasRΔrhlR group (2.15±1.43, P<0.05. The accumulated optical density value of TGF-β1 was significantly higher in the two Ps. aer infected groups than in sterile control group (3721.66±1412.95, and significantly higher in PAO1 group (65 090.56±33

  19. Comparative Response of the Hepatic Transcriptomes of Domesticated and Wild Turkey to Aflatoxin B1

    Directory of Open Access Journals (Sweden)

    Kent M. Reed

    2018-01-01

    Full Text Available The food-borne mycotoxin aflatoxin B1 (AFB1 poses a significant risk to poultry, which are highly susceptible to its hepatotoxic effects. Domesticated turkeys (Meleagris gallopavo are especially sensitive, whereas wild turkeys (M. g. silvestris are more resistant. AFB1 toxicity entails bioactivation by hepatic cytochrome P450s to the electrophilic exo-AFB1-8,9-epoxide (AFBO. Domesticated turkeys lack functional hepatic GST-mediated detoxification of AFBO, and this is largely responsible for the differences in resistance between turkey types. This study was designed to characterize transcriptional changes induced in turkey livers by AFB1, and to contrast the response of domesticated (susceptible and wild (more resistant birds. Gene expression responses to AFB1 were examined using RNA-sequencing. Statistically significant differences in gene expression were observed among treatment groups and between turkey types. Expression analysis identified 4621 genes with significant differential expression (DE in AFB1-treated birds compared to controls. Characterization of DE transcripts revealed genes dis-regulated in response to toxic insult with significant association of Phase I and Phase II genes and others important in cellular regulation, modulation of apoptosis, and inflammatory responses. Constitutive expression of GSTA3 was significantly higher in wild birds and was significantly higher in AFB1-treated birds when compared to controls for both genetic groups. This pattern was also observed by qRT-PCR in other wild and domesticated turkey strains. Results of this study emphasize the differential response of these genetically distinct birds, and identify genes and pathways that are differentially altered in aflatoxicosis.

  20. Development of a combined canine distemper virus specific RT-PCR protocol for the differentiation of infected and vaccinated animals (DIVA) and genetic characterization of the hemagglutinin gene of seven Chinese strains demonstrated in dogs.

    Science.gov (United States)

    Yi, Li; Cheng, Shipeng; Xu, Hongli; Wang, Jianke; Cheng, Yuening; Yang, Shen; Luo, Bin

    2012-01-01

    A combined reverse-transcription polymerase chain reaction (RT-PCR) method was developed for the detection and differentiation of wild-type and vaccine strains of the canine distemper virus (CDV). A pair of primers (P1/P2) was used to detect both CDV wild-type strains and vaccines. Another pair (P3/P4) was used to detect only CDV wild-type strains. A 335bp fragment was amplified from the genomic RNA of the vaccine and wild-type strains. A 555bp fragment was amplified specifically from the genomic RNA of the wild-type strains. No amplification was achieved for the uninfected cells, cells infected with canine parvovirus, canine coronavirus, or canine adenovirus. The combined RT-PCR method detected effectively and differentiated the CDV wild-type and vaccine strains by two separate RT-PCRs. The method can be used for clinical detection and epidemiological surveillance. The phylogenetic analysis of the hemagglutinin gene of the local wild-type CDV strains revealed that the seven local isolates all belonged to the Asia-1 lineage, and were clustered closely with one another at the same location. These results suggested that the CDV genotype Asia-1 is circulating currently in domestic dogs in China. Copyright © 2011 Elsevier B.V. All rights reserved.

  1. Reverting antibiotic tolerance of Pseudomonas aeruginosa PAO1 persister cells by (Z-4-bromo-5-(bromomethylene-3-methylfuran-2(5H-one.

    Directory of Open Access Journals (Sweden)

    Jiachuan Pan

    Full Text Available BACKGROUND: Bacteria are well known to form dormant persister cells that are tolerant to most antibiotics. Such intrinsic tolerance also facilitates the development of multidrug resistance through acquired mechanisms. Thus persister cells are a promising target for developing more effective methods to control chronic infections and help prevent the development of multidrug-resistant bacteria. However, control of persister cells is still an unmet challenge. METHODOLOGY/PRINCIPAL FINDINGS: We show in this report that (Z-4-bromo-5-(bromomethylene-3-methylfuran-2(5H-one (BF8 can restore the antibiotic susceptibility of Pseudomonas aeruginosa PAO1 persister cells at growth non-inhibitory concentrations. Persister control by BF8 was found to be effective against both planktonic and biofilm cells of P. aeruginosa PAO1. Interestingly, although BF8 is an inhibitor of quorum sensing (QS in Gram-negative bacteria, the data in this study suggest that the activities of BF8 to revert antibiotic tolerance of P. aeruginosa PAO1 persister cells is not through QS inhibition and may involve other targets. CONCLUSION: BF8 can sensitize P. aeruginosa persister cells to antibiotics.

  2. Action potentials and ion conductances in wild-type and CALHM1-knockout type II taste cells

    Science.gov (United States)

    Saung, Wint Thu; Foskett, J. Kevin

    2017-01-01

    Taste bud type II cells fire action potentials in response to tastants, triggering nonvesicular ATP release to gustatory neurons via voltage-gated CALHM1-associated ion channels. Whereas CALHM1 regulates mouse cortical neuron excitability, its roles in regulating type II cell excitability are unknown. In this study, we compared membrane conductances and action potentials in single identified TRPM5-GFP-expressing circumvallate papillae type II cells acutely isolated from wild-type (WT) and Calhm1 knockout (KO) mice. The activation kinetics of large voltage-gated outward currents were accelerated in cells from Calhm1 KO mice, and their associated nonselective tail currents, previously shown to be highly correlated with ATP release, were completely absent in Calhm1 KO cells, suggesting that CALHM1 contributes to all of these currents. Calhm1 deletion did not significantly alter resting membrane potential or input resistance, the amplitudes and kinetics of Na+ currents either estimated from action potentials or recorded from steady-state voltage pulses, or action potential threshold, overshoot peak, afterhyperpolarization, and firing frequency. However, Calhm1 deletion reduced the half-widths of action potentials and accelerated the deactivation kinetics of transient outward currents, suggesting that the CALHM1-associated conductance becomes activated during the repolarization phase of action potentials. NEW & NOTEWORTHY CALHM1 is an essential ion channel component of the ATP neurotransmitter release mechanism in type II taste bud cells. Its contribution to type II cell resting membrane properties and excitability is unknown. Nonselective voltage-gated currents, previously associated with ATP release, were absent in cells lacking CALHM1. Calhm1 deletion was without effects on resting membrane properties or voltage-gated Na+ and K+ channels but contributed modestly to the kinetics of action potentials. PMID:28202574

  3. Serial passaging of Candida albicans in systemic murine infection suggests that the wild type strain SC5314 is well adapted to the murine kidney.

    Directory of Open Access Journals (Sweden)

    Anja Lüttich

    Full Text Available The opportunistic fungal pathogen Candida albicans has a remarkable ability to adapt to unfavorable environments by different mechanisms, including microevolution. For example, a previous study has shown that passaging through the murine spleen can cause new phenotypic characteristics. Since the murine kidney is the main target organ in murine Candida sepsis and infection of the spleen differs from the kidney in several aspects, we tested whether C. albicans SC5314 could evolve to further adapt to infection and persistence within the kidney. Therefore, we performed a long-term serial passage experiment through the murine kidney of using a low infectious dose. We found that the overall virulence of the commonly used wild type strain SC5314 did not change after eight passages and that the isolated pools showed only very moderate changes of phenotypic traits on the population level. Nevertheless, the last passage showed a higher phenotypic variability and a few individual strains exhibited phenotypic alterations suggesting that microevolution has occurred. However, the majority of the tested single strains were phenotypically indistinguishable from SC5314. Thus, our findings indicate that characteristics of SC5314 which are important to establish and maintain kidney infection over a prolonged time are already well developed.

  4. Mutagenesis at the ad-3A and ad-3B loci in haploid UV-sensitive strains of Neurospora crassa. Pt. 3

    International Nuclear Information System (INIS)

    Schuepbach, M.E.; Serres, F.J. de

    1981-01-01

    γ-ray-induced inactivation and induction of mutations at the ad-3A and ad-3B loci of Neurospora crassa have been compared among 6 different UV- sensitive strains and a standard wild-type strain. The 6 strains show varying degrees of sensitivy to γ-ray-induced inactivation, with the relative sensitivy at 37% survival being uvs-6 > upr-1 > uvs-2 UE uvs-3 > wild-type > uvs-5 > uvs-4. Studies on the induction of ad-3 mutants by γ-rays show that when the dose-response curves (expressed in terms of ad-3 mutants among the surving colonies) of the UV-sensitive strains are compared with wild-type, the excision-repair-deficient mutants uvs-2 and upr-1 exhibit enhanced ad-3 mutant frequencies, uvs-3 exibits reduced ad-3 mutant frequencies whereas both uvs-4 and uvs-5 show lower mutant frequencies than wild-type. (orig.)

  5. Expression of type 2 diacylglycerol acyltransferse gene DGTT1 from Chlamydomonas reinhardtii enhances lipid production in Scenedesmus obliquus.

    Science.gov (United States)

    Chen, Chun-Yen; Kao, Ai-Ling; Tsai, Zheng-Chia; Chow, Te-Jin; Chang, Hsin-Yueh; Zhao, Xin-Qing; Chen, Po-Ting; Su, Hsiang-Yen; Chang, Jo-Shu

    2016-03-01

    Microalgal strains of Scenedesmus obliquus have the great potential for the production of biofuels, CO2 fixation, and bioremediation. However, metabolic engineering of S. obliquus to improve their useful phenotypes are still not fully developed. In this study, S. obliquus strain CPC2 was genetically engineered to promote the autotrophic growth and lipid productivity. The overexpression plasmid containing the type 2 diacylglycerol acyltransferse (DGAT) gene DGTT1 from Chlamydomonas reinhardtii was constructed and transformed into S. obliquus CPC2, and the positive transformants were obtained. The expression of DGTT1 gene was confirmed by reverse transcription PCR analysis. Enhanced lipid content of the transformant S. obliquus CPC2-G1 by nearly two-fold was observed. The biomass concentration of the recombinant strains was also 29% higher than that of the wild-type strain. Furthermore, the recombinant strain CPC2-G1 was successfully grown in 40 L tubular type photobioreactor and open pond system in an outdoor environment. The lipid content, biomass concentration, and biomass productivity obtained from 40 L tubular PBR were 127.8% 20.0%, and 232.6% higher than those obtained from the wild-type strain. The major aim of this work is to develop a tool to genetically engineer an isolated S. obliquus strain for the desired purpose. This is the first report that genetic engineering of S. obliquus has been successful employed to improve both the microalgal cell growth and the lipid production. Copyright © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Comparison of game-farm and wild-strain mallard ducks in accumulation of methylmercury

    Science.gov (United States)

    Heinz, G.H.

    1979-01-01

    The accumulation of mercury was compared in game-farm and wild-strain mallard ducks fed a diet containing 0.5 ppm mercury in the form of methylmercury dicyandiamide. There were no significant differences between the two strains in levels of mercury that accumulated in blood, kidney, liver, breast muscle, brain, eggs, or ducklings. Mercury levels in blood were significantly correlated with levels in other tissues and eggs, as were levels in down feathers of ducklings with levels in carcasses of ducklings. The results indicate that game-farm mallards are probably suitable substitutes for wild mallards in toxicological work, that blood samples can be used to estimate levels of mercury in other tissues of adults, and that down feathers are predictive of mercury levels in duckling carcasses.

  7. Draft genome sequence of Agrobacterium rhizogenes strain NCPPB2659

    Science.gov (United States)

    This work reports the draft genome of Agrobacterium rhizogenes strain NCPPB2659 (also known as strain K599). The assembled genome contains 5,277,347 bp, and is composed of 1 circular chromosome, the Ri virulence plasmid, and 17 scaffolds pertaining to the linear chromosome. The wild type strain cau...

  8. Increased riboflavin production from activated bleaching earth by a mutant strain of Ashbya gossypii.

    Science.gov (United States)

    Tajima, Satoshi; Itoh, Yoko; Sugimoto, Takashi; Kato, Tatsuya; Park, Enoch Y

    2009-10-01

    The production of riboflavin from vegetable oil was increased using a mutant strain of Ashbya gossypii. This mutant was generated by treating the wild-type strain with N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). Riboflavin production was 10-fold higher in the mutant compared to the wild-type strain. The specific intracellular catalase activity after 3 d of culture was 6-fold higher in the mutant than in the wild-type strain. For the mutant, riboflavin production in the presence of 40 mM hydrogen peroxide was 16% less than that in the absence of hydrogen peroxide, whereas it was 56% less for the wild-type strain. The isocitrate lyase (ICL) activity of the mutant was 0.26 mU/mg of protein during the active riboflavin production phase, which was 2.6-fold higher than the wild-type strain. These data indicate that the mutant utilizes the carbon flux from the TCA cycle to the glyoxylate cycle more efficiently than the wild-type strain, resulting in enhanced riboflavin production. This novel mutant has the potential to be of use for industrial-scale riboflavin production from waste-activated bleaching earth (ABE), thereby transforming a useless material into a valuable bioproduct.

  9. Courtship behavior of different wild strains of Ceratitis Capitata (Diptera: Tephritidae)

    International Nuclear Information System (INIS)

    Briceno, D.; Eberhard, W.; Vilardi, J.; Cayol, J.-P.; Shelly, T.

    2007-01-01

    This study documents differences in the courtship behavior of wild strains of Ceratitis capitata (Wiedemann) from Madeira (Portugal), Hawaii (U.S.A.), Costa Rica, and Patagonia (Argentina). Some traits showed large variations and others substantial overlaps. The angle at which the male faced toward the female at the moment of transition from continuous wing vibration and intermittent buzzing changed very little during the course of courtship in all strains, but males from Madeira tended to face more directly toward the female than other males. Females tended to look more, and more directly, toward the males as courtship progressed in all strains. The distance between male and female tended to decrease as courtship proceeded in all strains, but the distances at which males initiated continuous vibration, intermittent buzzing, and jumped onto the female were relatively less variable between strains, except for the strain from Costa Rica. Flies of Madeira courted for longer and the male moved his head and buzzed his wings longer than the other strains. (author) [es

  10. R5 strains of human immunodeficiency virus type 1 from rapid progressors lacking X4 strains do not possess X4-type pathogenicity in human thymus

    NARCIS (Netherlands)

    Berkowitz, R. D.; van't Wout, A. B.; Kootstra, N. A.; Moreno, M. E.; Linquist-Stepps, V. D.; Bare, C.; Stoddart, C. A.; Schuitemaker, H.; McCune, J. M.

    1999-01-01

    Some individuals infected with only R5 strains of human immunodeficiency virus type 1 progress to AIDS as quickly as individuals harboring X4 strains. We determined that three R5 viruses were much less pathogenic than an X4 virus in SCID-hu Thy/Liv mice, suggesting that R5 virus-mediated rapid

  11. Development of Biotin-Prototrophic and -Hyperauxotrophic Corynebacterium glutamicum Strains

    Science.gov (United States)

    Miyamoto, Aya; Mutoh, Sumire; Kitano, Yuko; Tajima, Mei; Shirakura, Daisuke; Takasaki, Manami; Mitsuhashi, Satoshi; Takeno, Seiki

    2013-01-01

    To develop the infrastructure for biotin production through naturally biotin-auxotrophic Corynebacterium glutamicum, we attempted to engineer the organism into a biotin prototroph and a biotin hyperauxotroph. To confer biotin prototrophy on the organism, the cotranscribed bioBF genes of Escherichia coli were introduced into the C. glutamicum genome, which originally lacked the bioF gene. The resulting strain still required biotin for growth, but it could be replaced by exogenous pimelic acid, a source of the biotin precursor pimelate thioester linked to either coenzyme A (CoA) or acyl carrier protein (ACP). To bridge the gap between the pimelate thioester and its dedicated precursor acyl-CoA (or -ACP), the bioI gene of Bacillus subtilis, which encoded a P450 protein that cleaves a carbon-carbon bond of an acyl-ACP to generate pimeloyl-ACP, was further expressed in the engineered strain by using a plasmid system. This resulted in a biotin prototroph that is capable of the de novo synthesis of biotin. On the other hand, the bioY gene responsible for biotin uptake was disrupted in wild-type C. glutamicum. Whereas the wild-type strain required approximately 1 μg of biotin per liter for normal growth, the bioY disruptant (ΔbioY) required approximately 1 mg of biotin per liter, almost 3 orders of magnitude higher than the wild-type level. The ΔbioY strain showed a similar high requirement for the precursor dethiobiotin, a substrate for bioB-encoded biotin synthase. To eliminate the dependency on dethiobiotin, the bioB gene was further disrupted in both the wild-type strain and the ΔbioY strain. By selectively using the resulting two strains (ΔbioB and ΔbioBY) as indicator strains, we developed a practical biotin bioassay system that can quantify biotin in the seven-digit range, from approximately 0.1 μg to 1 g per liter. This bioassay proved that the engineered biotin prototroph of C. glutamicum produced biotin directly from glucose, albeit at a marginally

  12. Development of biotin-prototrophic and -hyperauxotrophic Corynebacterium glutamicum strains.

    Science.gov (United States)

    Ikeda, Masato; Miyamoto, Aya; Mutoh, Sumire; Kitano, Yuko; Tajima, Mei; Shirakura, Daisuke; Takasaki, Manami; Mitsuhashi, Satoshi; Takeno, Seiki

    2013-08-01

    To develop the infrastructure for biotin production through naturally biotin-auxotrophic Corynebacterium glutamicum, we attempted to engineer the organism into a biotin prototroph and a biotin hyperauxotroph. To confer biotin prototrophy on the organism, the cotranscribed bioBF genes of Escherichia coli were introduced into the C. glutamicum genome, which originally lacked the bioF gene. The resulting strain still required biotin for growth, but it could be replaced by exogenous pimelic acid, a source of the biotin precursor pimelate thioester linked to either coenzyme A (CoA) or acyl carrier protein (ACP). To bridge the gap between the pimelate thioester and its dedicated precursor acyl-CoA (or -ACP), the bioI gene of Bacillus subtilis, which encoded a P450 protein that cleaves a carbon-carbon bond of an acyl-ACP to generate pimeloyl-ACP, was further expressed in the engineered strain by using a plasmid system. This resulted in a biotin prototroph that is capable of the de novo synthesis of biotin. On the other hand, the bioY gene responsible for biotin uptake was disrupted in wild-type C. glutamicum. Whereas the wild-type strain required approximately 1 μg of biotin per liter for normal growth, the bioY disruptant (ΔbioY) required approximately 1 mg of biotin per liter, almost 3 orders of magnitude higher than the wild-type level. The ΔbioY strain showed a similar high requirement for the precursor dethiobiotin, a substrate for bioB-encoded biotin synthase. To eliminate the dependency on dethiobiotin, the bioB gene was further disrupted in both the wild-type strain and the ΔbioY strain. By selectively using the resulting two strains (ΔbioB and ΔbioBY) as indicator strains, we developed a practical biotin bioassay system that can quantify biotin in the seven-digit range, from approximately 0.1 μg to 1 g per liter. This bioassay proved that the engineered biotin prototroph of C. glutamicum produced biotin directly from glucose, albeit at a marginally

  13. Sublethal Ciprofloxacin Treatment Leads to Rapid Development of High-Level Ciprofloxacin Resistance during Long-Term Experimental Evolution of Pseudomonas aeruginosa

    DEFF Research Database (Denmark)

    Jørgensen, Karin Meinike; Wassermann, Tina; Jensen, Peter Østrup

    2013-01-01

    that mutants with high-level ciprofloxacin resistance are selected in P. aeruginosa bacterial populations exposed to sub-MICs of ciprofloxacin. This can have implications for the long-term persistence of resistant bacteria and spread of antibiotic resistance by exposure of commensal bacterial flora to low......The dynamics of occurrence and the genetic basis of ciprofloxacin resistance were studied in a long-term evolution experiment (940 generations) in wild-type, reference strain (PAO1) and hypermutable (PAOΔmutS and PAOMY-Mgm) P. aeruginosa populations continuously exposed to sub-MICs (1....../4) of ciprofloxacin. A rapid occurrence of ciprofloxacin-resistant mutants (MIC of ≥12 μg/ml, representing 100 times the MIC of the original population) were observed in all ciprofloxacin-exposed lineages of PAOΔmutS and PAOMY-Mgm populations after 100 and 170 generations, respectively, and in one of the PAO1...

  14. Comparison of Ehrlichia muris Strains Isolated from Wild Mice and Ticks and Serologic Survey of Humans and Animals with E. muris as Antigen

    OpenAIRE

    Kawahara, Makoto; Ito, Tadahiko; Suto, Chiharu; Shibata, Shinichiro; Rikihisa, Yasuko; Hata, Kazuhisa; Hirai, Katsuya

    1999-01-01

    In metropolitan Tokyo, the Ehrlichia muris seropositivity rate of 24 wild mice was 63% in Hinohara Village, but in the surrounding areas, it was 0 to 5%. This finding suggests that the reservoir of E. muris is focal. Among the 15 seropositive mice, ehrlichiae were isolated from 9 Apodemus speciosus mice and 1 A. argenteus mouse, respectively. Five ehrlichial isolates were obtained from 10 ticks (Haemaphysalis flava) collected in Asuke Town, Aichi Prefecture, where the E. muris type strain had...

  15. Evidence for three types of x-ray damage repair in yeast and sensitivity of totally repair deficient strains to sunlight

    International Nuclear Information System (INIS)

    Game, J.C.; Schild, D.; Mortimer, R.K.

    1987-01-01

    Mutants of yeast that confer sensitivity to x-rays are known to fall into two epistasis groups, called here the RAD51 and RAD18 groups, which are each thought to control a different type of x-ray repair. They examine here the role of genes in a third repair pathways in x-ray repair. RAD1 and RAD3 are known to be important in the repair of pyrimidine dimers after uv-irradiation. They find that these genes can also play an important role in x-ray repair, but that this role is only exposed when both the other pathways of x-ray repair are blocked. Double mutants blocked in the RAD51 and RAD18 pathways are significantly less x-ray sensitive than triple mutants blocked in these pathways but also mutant in either the RAD1 or RAD3 genes. In a related experiment, they tested the importance of DNA repair in nature by determining the sensitivity to natural unfiltered sunlight of a strain lacking all known DNA repair pathways. They constructed a quadruple mutant strain containing RAD1-1, RAD18-2, RAD51-1 and PHR1-1. The latter mutation blocks the cell's ability to photoreactivate uv damage. They found that this strain was so sensitive to sunlight that less than three seconds' exposure would cause an average of one lethal hit per cell, and survival was less than 2% after ten seconds' exposure. Wild type yeast at sea level showed no killing after thirty minutes. the quadruple mutant is approximately one thousand times more sensitive to sunlight than the related wild type

  16. Short communication: Antiproliferative effect of wild Lactobacillus strains isolated from fermented foods on HT-29 cells.

    Science.gov (United States)

    Tuo, Y F; Zhang, L W; Yi, H X; Zhang, Y C; Zhang, W Q; Han, X; Du, M; Jiao, Y H; Wang, S M

    2010-06-01

    In vitro studies, animal models, epidemiology, and human intervention studies provide evidence that some lactic acid bacteria can reduce the risk of certain cancers. In this study, heat-killed bacterial cells, genomic DNA, and cell wall of 7 wild Lactobacillus strains isolated from traditional fermented foods in western China were tested in vitro for cytotoxicity on colonic cancer cell line HT-29 by using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The heat-killed bacterial cells, genomic DNA, and cell wall of the 7 strains exhibited direct antiproliferative activities against HT-29 cells. Among the strains, the cellular components of Lactobacillus coryniformis ssp. torquens T3L exerted marked antiproliferative activities against HT-29 cells. The maximum inhibition rates of HT-29 cells by the heat-killed bacterial cells (1x10(7) cfu/mL), cell wall (20 microg of protein/mL) and genomic DNA (100 microg/mL) of L. coryniformis ssp. torquens T3L were 30, 44.9, and 35.9%, respectively. The results indicate that the heat-killed bacterial cells, cell wall, and genomic DNA of the 7 wild Lactobacillus strains could inhibit the growth of HT-29 cells. 2010 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  17. Molecular cloning and characterization of the recA gene of Pseudomonas aeruginosa PAO

    Energy Technology Data Exchange (ETDEWEB)

    Kokjohn, T.A.; Miller, R.V.

    1985-08-01

    The recA gene of Pseudomonas aeruginosa PAO has been isolated and introduced into Escherichia coli K-12. Resistance to killing by UV irradiation was restored in several RecA-E. coli K-12 hosts by the P. aeruginosa gene, as was resistance to methyl methanesulfonate. Recombination proficiency was also restored, as measured by HfrH-mediated conjugation and by the ability to propagate Fec-phage lambda derivatives. The cloned P. aeruginosa recA gene restored both spontaneous and mitomycin C-stimulated induction of lambda prophage in lysogens of a recA strain of E. coli K-12.

  18. Safety evaluation of pectin-derived acidic oligosaccharides (pAOS): genotoxicity and sub-chronic studies.

    NARCIS (Netherlands)

    Garthoff, J.A.; Heemskerk, S.; Hempenius, R.A.; Lina, B.A.; Krul, C.A.; Koeman, J.H.; Speijers, G.J.

    2010-01-01

    Pectin-derived acidic oligosaccharides (pAOS) are non-digestible carbohydrates to be used in infant formulae and medical nutrition. To support its safety, the genotoxic potential of pAOS was evaluated. pAOS was not mutagenic in the Ames test. Positive results were obtained in the chromosome

  19. Safety evaluation of pectin-derived acidic oligosaccharides (pAOS): Genotoxicity and sub-chronic studies

    NARCIS (Netherlands)

    Garthoff, J.A.; Heemskerk, S.; Hempenius, R.A.; Lina, B.A.R.; Krul, C.A.M.; Koeman, J.H.; Speijers, G.J.A.

    2010-01-01

    Pectin-derived acidic oligosaccharides (pAOS) are non-digestible carbohydrates to be used in infant formulae and medical nutrition. To support its safety, the genotoxic potential of pAOS was evaluated. pAOS was not mutagenic in the Ames test. Positive results were obtained in the chromosome

  20. Heterogeneity of biofilms formed by nonmucoid Pseudomonas aeruginosa isolates from patients with cystic fibrosis

    DEFF Research Database (Denmark)

    Lee, Baoleri; Haagensen, Janus Anders Juul; Ciofu, O.

    2005-01-01

    lactone quorum-sensing molecules). Compared with wild-type strain PAO 1, most P. aeruginosa isolates demonstrated different degrees of reduction of adherence on polystyrene surfaces. The in vitro biofilm formation of isolates was investigated in a hydrodynamic flow system. Confocal laser scanning...... to phenotypic changes and in vitro biofilm formation. The physiological alterations were associated with a loss of motility (35% were nonmotile) and with decreased production of virulence factors (pyocyanin, proteases) and quorum-sensing molecules (45% of the isolates were unable to produce 3-O-C(12)-homoserine...

  1. Comparison of Tc-99m HM-PAO and I-123 IMP cerebral SPECT images in Alzheimer's disease and multi-infarct dementia

    Energy Technology Data Exchange (ETDEWEB)

    Gemmell, H G; Sharp, P F; Besson, J A.O.; Ebmeier, K P; Smith, F W

    1988-10-01

    SPECT images of the brain can be obtained using either /sup 123/I labelled amines or /sup 99m/Tc-hexamethylpropyleneamineoxime (HM-PAO). Both materials produce images which are blood flow dominated and so appear similar in normal subjects, although the respective mechanisms of uptake are not yet finally established. It seems likely, however, that the different mechanisms of uptake are responsible for recent reports of some differences seen in images obtained with the two types of agent in patients with cerebral pathology, mainly cerebrovascular disease. In this study, 12 demented patients, 6 with dementia of the Alzheimer type (DAT) and 6 with multi infarct dementia (MID), were imaged with /sup 123/I-isopropylamphetamine (IMP) and /sup 99m/Tc-HM-PAO and the images compared. Significantly more lesions were seen with IMP than HM-PAO (P < 0.02); out of a possible 120 sites, 41 lesions were seen with IMP compared to 28 with HM-PAO, 23 being seen with both agents. However, it is concluded that either agent can be used for the differential diagnosis of dementia, a task for which the new cerebral blood flow agents seem well suited.

  2. Expression, purification, crystallization and preliminary crystallographic analysis of PA3885 (TpbA) from Pseudomonas aeruginosa PAO1

    International Nuclear Information System (INIS)

    Yang, Wen; Li, Kan; Bai, Yuwei; Zhou, Ruimin; Zhou, Weihong; Bartlam, Mark

    2010-01-01

    PA3885 (TpbA), a tyrosine phosphatase, may function as a balancing factor between biofilm formation and motility in the opportunistic pathogen P. aeruginosa. Here, the expression, purification, crystallization and preliminary crystallographic analysis of PA3885 from P. aeruginosa PAO1 are reported. Biofilms are important in cell communication and growth in most bacteria and are also responsible for most human clinical infections and diseases. Quorum-sensing systems have been identified to be crucial for biofilm formation and regulation. PA3885 (TpbA), a tyrosine phosphatase, is reported to convert extracellular quorum-sensing signals into internal gene-cascade reactions that result in reduced biofilm formation in the opportunistic pathogen Pseudomonas aeruginosa. Here, PA3885 from P. aeruginosa PAO1 was expressed, purified and crystallized. Single crystals were studied by X-ray crystallography and native diffraction data were collected to 2.8 Å resolution. These crystals were determined to belong to space group C2. It was not possible to conclusively determine the number of proteins in the asymmetric unit from the preliminary X-ray diffraction data analysis alone and attempts to determine the crystal structure of PA3885 are currently under way

  3. Porphyrin Interactions with Wild Type and Mutant Mouse Ferrochelatase

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Gloria C.; Franco, Ricardo; Lu, Yi; Ma, Jian-Guo; Shelnutt, John A.

    1999-05-19

    Ferrochelatase (EC 4.99.1.1), the terminal enzyme of the heme biosynthetic pathway, catalyzes Fe2+ chelation into protoporphyrin IX. Resonance Raman and W-visible absorbance spectroscopes of wild type and engineered variants of murine ferrochelatase were used to examine the proposed structural mechanism for iron insertion into protoporphyrin by ferrochelatase. The recombinant variants (i.e., H207N and E287Q) are enzymes in which the conserved amino acids histidine-207 and glutamate-287 of murine ferrochelatase were substituted with asparagine and glutamine, respectively. Both of these residues are at the active site of the enzyme as deduced from the Bacillus subtilis ferrochelatase three-dimensional structure. Addition of free base or metalated porphyrins to wild type ferrochelatase and H207N variant yields a quasi 1:1 complex, possibly a monomeric protein-bound species. In contrast, the addition of porphyrin (either free base or metalated) to E287Q is sub-stoichiometric, as this variant retains bound porphyrin in the active site during isolation and purification. The specificity of porphyrin binding is confirmed by the narrowing of the structure-sensitive resonance Raman lines and the vinyl vibrational mode. Resonance Raman spectra of free base and metalated porphyrins bound to the wild type ferrochelatase indicate a nonplanar distortion of the porphyrin macrocycle, although the magnitude of the distortion cannot be determined without first defining the specific type of deformation. Significantly, the extent of the nonplanar distortion varies in the case of H207N- and E287Q-bound porphyrins. In fact, resonance Raman spectral decomposition indicates a homogeneous ruffled distortion for the nickel protoporphyrin bound to the wild type ferrochelatase, whereas both a planar and ruffled conformations are present for the H207N-bound porphyrin. Perhaps more revealing is the unusual resonance , 3 Raman spectrum of the endogenous E287Q-bound porphyrin, which has

  4. Mutational analysis of the multicopy hao gene coding for hydroxylamine oxidoreductase in Nitrosomonas sp. strain ENI-11.

    Science.gov (United States)

    Yamagata, A; Hirota, R; Kato, J; Kuroda, A; Ikeda, T; Takiguchi, N; Ohtake, H

    2000-08-01

    The ammonia-oxidizing bacterium Nitrosomonas sp. strain ENI-11 contains three copies of the hao gene (hao1, hao2, and hao3) coding for hydroxylamine oxidoreductase (HAO). Three single mutants (hao1::kan, hao2::kan, or hao3::kan) had 68 to 75% of the wild-type growth rate and 58 to 89% of the wild-type HAO activity when grown under the same conditions. A double mutant (hao1::kan and hao3::amp) also had 68% of the wild-type growth and 37% of the wild-type HAO activity.

  5. Induction of pure and sectored mutant clones in excision-proficient and deficient strains of yeast.

    Science.gov (United States)

    Eckardt, F; Haynes, R H

    1977-06-01

    We have found that UV-induced mutation frequency in a forward non-selective assay system (scoring white adex ade2 double auxotroph mutants among the red pigmented ade2 clones) increases linearly with dose up to a maximum frequency of about 3 X 10(-3) mutants per survivor and then declines in both RAD wild-type and rad2 excision deficient strains of Saccharomyces cerevisiae. Mutation frequencies of the RAD and the rad2 strains plotted against survival are nearly identical over the entire survival range. On this basis we conclude that unexcised pyrimidine dimers are the predominant type of pre-mutational lesions in both strains. In the RAD wild-type strain pure mutant clones outnumber sectors in a 10:1 ratio at all doses used; in rad2 this ratio varies from 1:1 at low doses up to 10:1 at high doses. As others have concluded for wild-type strains we find also in the rad2 strain that pure clone formation cannot be accounted for quantitatively by lethal sectoring events alone. We conclude that heteroduplex repair is a crucial step in pure mutant clone formation and we examine the plausibility of certain macromolecular mechanisms according to which heteroduplex repair may be coupled with replication, repair and sister strand exchange in yeast mutagenesis.

  6. Induction of pure and sectored mutant clones in excision-proficient and deficient strains of yeast

    International Nuclear Information System (INIS)

    Eckardt, F.; Haynes, R.H.

    1977-01-01

    It was found that UV-induced mutation frequency in a forward non-selective assay system (scoring white adex ade2 double auxotroph mutants among the red pigmented ade2 clones) increases linearly with dose up to a maximum frequency of about 3 x 10 -3 mutants per survivor and then declines in both RAD wild-type and rad2 excision deficient strains of Saccharomyces cerevisiae. Mutation frequencies of the RAD and the rad2 strains plotted against survival are nearly identical over the entire survival range. On this basis it is concluded that unexcised pyrimidine dimers are the predominant type of pre-mutational lesions in both strains. In the RAD wild-type strain pure mutant clones outnumber sectors in a 10:1 ratio at all doses used; in rad2 this ratio varies from 1:1 at low doses up to 10:1 at high doses. In agreement with conclusions of others, it was also found that for wild-type strains in the rad2 strain pure clone formation cannot be accounted for quantitatively by lethal sectoring events alone. It is concluded that heteroduplex repair is a crucial step in pure mutant clone formation and the plausibility of certain macromolecular mechanisms according to which heteroduplex repair may be coupled with replication, repair and sister strand exchange in yeast mutagenesis is examined

  7. The evolution of pigeon paramyxovirus type 1 (PPMV-1) in Great Britain: a molecular epidemiological study.

    Science.gov (United States)

    Aldous, E W; Fuller, C M; Ridgeon, J H; Irvine, R M; Alexander, D J; Brown, I H

    2014-04-01

    Newcastle disease (ND), caused by virulent strains of avian paramyxovirus type 1 (APMV-1), is considered throughout the world as one of the most important animal diseases. For over three decades now, there has been a continuing panzootic caused by a variant virulent APMV-1 strain, so-called pigeon paramyxovirus type 1 (PPMV-1), primarily in racing pigeons, which has also spread to wild birds and poultry. PPMV-1 isolations have been made in Great Britain every year since 1983. In this study, we have completed a comparative phylogenetic analysis based on a 374 nucleotide section of the fusion protein gene of 63 isolates of PPMV-1 that were isolated over a 26-year period; 43 of these were sequenced for this study. Phylogenetic analysis of these sequences revealed that all were closely related and placed in the genetic sublineage 4b (VIb), subdivision 4biif. © 2012 Crown copyright.

  8. New Germplasms of the Culinary-Medicinal Button Mushroom, Agaricus bisporus (Agaricomycetes): Two Wild Strains from the Tibetan Plateau (China).

    Science.gov (United States)

    Li, Bin-Bin; Jiang, Si-Ping; Xu, Ai-Guo; Dorji, Phurbu; Wang, Wen-Jing; Wang, Xiao-Liang; Wei, Tie-Zheng; Zhang, Zu-Tang; Yao, Yi-Jian

    2017-01-01

    Agaricus bisporus is one of the most important commercially cultivated culinary-medicinal mushrooms worldwide. In China, most of the cultivated strains of the fungus were introduced from other countries and cultivated in the eastern provinces. In this study, 2 wild strains of A. bisporus, 2091 and 2094, isolated from fresh specimens collected from the Tibetan Plateau, were domesticated and cultivated alongside a commercial hybrid strain, As2796, in Lhasa, China, for comparison in order to provide new germplasms for cultivation. Basic characteristics, mushroom yield, dry weight, polysaccharide contents, and antioxidant activities of the tested strains were analyzed. Compared with strain As2796, the 2 wild strains displayed good values for mycelial growth, time to fruiting, mushroom yield, dry weight, and polysaccharide contents, and their basidiomata had distinct morphological characteristics (e.g., brown or pale brown caps with some white scales). In addition, the antioxidant activities (reducing power and DPPH radical scavenging effect) of strain 2094 were significantly higher than those of the other 2 strains. Domestication of the 2 wild strains would add more genetic variation into the germplasm of A. bisporus for cultivation, especially in China, and might help to address the problem inherent to the nearly monoculture crop lacking genetic diversity in China.

  9. Development of carbapenem resistance in Pseudomonas aeruginosa is associated with OprD polymorphisms, particularly the amino acid substitution at codon 170.

    Science.gov (United States)

    Shu, Jwu-Ching; Kuo, An-Jing; Su, Lin-Hui; Liu, Tsui-Ping; Lee, Ming-Hsun; Su, I-Ning; Wu, Tsu-Lan

    2017-09-01

    Pan-susceptible Pseudomonas aeruginosa (PSPA) clinical isolates carrying an OprD with loop 7 shortening (the group-1A allele) were found to rapidly develop carbapenem resistance under continuous selection pressure. We further studied whether OprD polymorphisms are associated with the potential to develop carbapenem resistance. OprD amino acid sequences of 126 PSPA clinical isolates were analysed to determine their STs using P. aeruginosa strain PAO1 as the control strain. Site-directed mutagenesis was performed in PAO1 to generate polymorphisms of interest. A disc diffusion method was used to select carbapenem-resistant variants from the mutant strains. Expression levels of oprD were determined by quantitative RT-PCR. MICs of carbapenems were determined by Etest. Forty-eight (38.1%) of the tested isolates carried the group-1A allele. Another two major STs, C1 and C2, both of which harboured an F170L polymorphism, were found in 21 (16.7%) and 39 (31.0%) isolates, respectively. The PAO1 type was also found in 14 (11.1%) isolates. Under continuous selective pressure, isolates of most STs developed carbapenem resistance at different numbers of passaging events; only those belonging to the PAO1 type remained susceptible. However, PAO1 mutants carrying either the oprD group-1A allele or the OprD-F170L polymorphism were able to develop carbapenem resistance. Reduced oprD expression triggered by continuous imipenem challenge was found in PAO1 mutants, but not in the PAO1 WT strain. OprD polymorphisms, particularly the F170L substitution and the specific shortening in loop 7, appear to determine the potential for P. aeruginosa to develop carbapenem resistance. © The Author 2017. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  10. CBF tomograms with (/sup 99m/Tc-HM-PAO in patients with dementia (Alzheimer type and HIV) and Parkinson's disease--initial results

    Energy Technology Data Exchange (ETDEWEB)

    Costa, D.C.; Ell, P.J.; Burns, A.; Philpot, M.; Levy, R.

    1988-12-01

    We present preliminary data on the utility of functional brain imaging with (99mTc)-d,l-HM-PAO and single photon emission computed tomography (SPECT) in the study of patients with dementia of the Alzheimer type (DAT), HIV-related dementia syndrome, and the on-off syndrome of Parkinson's disease. In comparison with a group of age-matched controls, the DAT patients revealed distinctive bilateral temporal and posterior parietal deficits, which correlate with detailed psychometric evaluation. Patients with amnesia as the main symptom (group A) showed bilateral mesial temporal lobe perfusion deficits (p less than 0.02). More severely affected patients (group B) with significant apraxia, aphasia, or agnosia exhibited patterns compatible with bilateral reduced perfusion in the posterior parietal cortex, as well as reduced perfusion to both temporal lobes, different from the patients of the control group (p less than 0.05). SPECT studies of HIV patients with no evidence of intracraneal space occupying pathology showed marked perfusion deficits. Patients with Parkinson's disease and the on-off syndrome studied during an on phase (under levodopa therapy) and on another occasion after withdrawal of levodopa (off) demonstrated a significant change in the uptake of (99mTc)-d,l-HM-PAO in the caudate nucleus (lower on off) and thalamus (higher on off). These findings justify the present interest in the functional evaluation of the brain of patients with dementia. (99mTc)-d,l-HM-PAO and regional cerebral blood flow (rCBF)/SPECT appear useful and highlight individual disorders of flow in a variety of neuropsychiatric conditions.

  11. Prior Inoculation with Type B Strains of Francisella tularensis Provides Partial Protection against Virulent Type A Strains in Cottontail Rabbits.

    Directory of Open Access Journals (Sweden)

    Vienna R Brown

    Full Text Available Francisella tularensis is a highly virulent bacterium that is capable of causing severe disease (tularemia in a wide range of species. This organism is characterized into two distinct subspecies: tularensis (type A and holarctica (type B which vary in several crucial ways, with some type A strains having been found to be considerably more virulent in humans and laboratory animals. Cottontail rabbits have been widely implicated as a reservoir species for this subspecies; however, experimental inoculation in our laboratory revealed type A organisms to be highly virulent, resulting in 100% mortality following challenge with 50-100 organisms. Inoculation of cottontail rabbits with the same number of organisms from type B strains of bacteria was found to be rarely lethal and to result in a robust humoral immune response. The objective of this study was to characterize the protection afforded by a prior challenge with type B strains against a later inoculation with a type A strain in North American cottontail rabbits (Sylvilagus spp. Previous infection with a type B strain of organism was found to lengthen survival time and in some cases prevent death following inoculation with a type A2 strain of F. tularensis. In contrast, inoculation of a type A1b strain was uniformly lethal in cottontail rabbits irrespective of a prior type B inoculation. These findings provide important insight about the role cottontail rabbits may play in environmental maintenance and transmission of this organism.

  12. Filament-producing mutants of influenza A/Puerto Rico/8/1934 (H1N1 virus have higher neuraminidase activities than the spherical wild-type.

    Directory of Open Access Journals (Sweden)

    Jill Seladi-Schulman

    Full Text Available Influenza virus exhibits two morphologies - spherical and filamentous. Strains that have been grown extensively in laboratory substrates are comprised predominantly of spherical virions while clinical or low passage isolates produce a mixture of spheres and filamentous virions of varying lengths. The filamentous morphology can be lost upon continued passage in embryonated chicken eggs, a common laboratory substrate for influenza viruses. The fact that the filamentous morphology is maintained in nature but lost in favor of a spherical morphology in ovo suggests that filaments confer a selective advantage within the infected host that is not necessary for growth in laboratory substrates. Indeed, we have recently shown that filament-producing variant viruses are selected upon passage of the spherical laboratory strain A/Puerto Rico/8/1934 (H1N1 [PR8] in guinea pigs. Toward determining the nature of the selective advantage conferred by filaments, we sought to identify functional differences between spherical and filamentous particles. We compared the wild-type PR8 virus to two previously characterized recombinant PR8 viruses in which single point mutations within M1 confer a filamentous morphology. Our results indicate that these filamentous PR8 mutants have higher neuraminidase activities than the spherical PR8 virus. Conversely, no differences were observed in HAU:PFU or HAU:RNA ratios, binding avidity, sensitivity to immune serum in hemagglutination inhibition assays, or virion stability at elevated temperatures. Based on these results, we propose that the pleomorphic nature of influenza virus particles is important for the optimization of neuraminidase functions in vivo.

  13. Screening and Expression of a Silicon Transporter Gene (Lsi1) in Wild-Type Indica Rice Cultivars

    Science.gov (United States)

    Abiri, Rambod; Kalhori, Nahid; Atabaki, Narges

    2017-01-01

    Silicon (Si) is one of the most prevalent elements in the soil. It is beneficial for plant growth and development, and it contributes to plant defense against different stresses. The Lsi1 gene encodes a Si transporter that was identified in a mutant Japonica rice variety. This gene was not identified in fourteen Malaysian rice varieties during screening. Then, a mutant version of Lsi1 was substituted for the native version in the three most common Malaysian rice varieties, MR219, MR220, and MR276, to evaluate the function of the transgene. Real-time PCR was used to explore the differential expression of Lsi1 in the three transgenic rice varieties. Silicon concentrations in the roots and leaves of transgenic plants were significantly higher than in wild-type plants. Transgenic varieties showed significant increases in the activities of the enzymes SOD, POD, APX, and CAT; photosynthesis; and chlorophyll content; however, the highest chlorophyll A and B levels were observed in transgenic MR276. Transgenic varieties have shown a stronger root and leaf structure, as well as hairier roots, compared to the wild-type plants. This suggests that Lsi1 plays a key role in rice, increasing the absorption and accumulation of Si, then alters antioxidant activities, and improves morphological properties. PMID:28191468

  14. Screening and Expression of a Silicon Transporter Gene (Lsi1 in Wild-Type Indica Rice Cultivars

    Directory of Open Access Journals (Sweden)

    Mahbod Sahebi

    2017-01-01

    Full Text Available Silicon (Si is one of the most prevalent elements in the soil. It is beneficial for plant growth and development, and it contributes to plant defense against different stresses. The Lsi1 gene encodes a Si transporter that was identified in a mutant Japonica rice variety. This gene was not identified in fourteen Malaysian rice varieties during screening. Then, a mutant version of Lsi1 was substituted for the native version in the three most common Malaysian rice varieties, MR219, MR220, and MR276, to evaluate the function of the transgene. Real-time PCR was used to explore the differential expression of Lsi1 in the three transgenic rice varieties. Silicon concentrations in the roots and leaves of transgenic plants were significantly higher than in wild-type plants. Transgenic varieties showed significant increases in the activities of the enzymes SOD, POD, APX, and CAT; photosynthesis; and chlorophyll content; however, the highest chlorophyll A and B levels were observed in transgenic MR276. Transgenic varieties have shown a stronger root and leaf structure, as well as hairier roots, compared to the wild-type plants. This suggests that Lsi1 plays a key role in rice, increasing the absorption and accumulation of Si, then alters antioxidant activities, and improves morphological properties.

  15. Screening and Expression of a Silicon Transporter Gene (Lsi1) in Wild-Type Indica Rice Cultivars.

    Science.gov (United States)

    Sahebi, Mahbod; Hanafi, Mohamed M; Rafii, M Y; Azizi, Parisa; Abiri, Rambod; Kalhori, Nahid; Atabaki, Narges

    2017-01-01

    Silicon (Si) is one of the most prevalent elements in the soil. It is beneficial for plant growth and development, and it contributes to plant defense against different stresses. The Lsi1 gene encodes a Si transporter that was identified in a mutant Japonica rice variety. This gene was not identified in fourteen Malaysian rice varieties during screening. Then, a mutant version of Lsi1 was substituted for the native version in the three most common Malaysian rice varieties, MR219, MR220, and MR276, to evaluate the function of the transgene. Real-time PCR was used to explore the differential expression of Lsi1 in the three transgenic rice varieties. Silicon concentrations in the roots and leaves of transgenic plants were significantly higher than in wild-type plants. Transgenic varieties showed significant increases in the activities of the enzymes SOD, POD, APX, and CAT; photosynthesis; and chlorophyll content; however, the highest chlorophyll A and B levels were observed in transgenic MR276. Transgenic varieties have shown a stronger root and leaf structure, as well as hairier roots, compared to the wild-type plants. This suggests that Lsi1 plays a key role in rice, increasing the absorption and accumulation of Si, then alters antioxidant activities, and improves morphological properties.

  16. Comparison of the live attenuated yellow fever vaccine 17D-204 strain to its virulent parental strain Asibi by deep sequencing.

    Science.gov (United States)

    Beck, Andrew; Tesh, Robert B; Wood, Thomas G; Widen, Steven G; Ryman, Kate D; Barrett, Alan D T

    2014-02-01

    The first comparison of a live RNA viral vaccine strain to its wild-type parental strain by deep sequencing is presented using as a model the yellow fever virus (YFV) live vaccine strain 17D-204 and its wild-type parental strain, Asibi. The YFV 17D-204 vaccine genome was compared to that of the parental strain Asibi by massively parallel methods. Variability was compared on multiple scales of the viral genomes. A modeled exploration of small-frequency variants was performed to reconstruct plausible regions of mutational plasticity. Overt quasispecies diversity is a feature of the parental strain, whereas the live vaccine strain lacks diversity according to multiple independent measurements. A lack of attenuating mutations in the Asibi population relative to that of 17D-204 was observed, demonstrating that the vaccine strain was derived by discrete mutation of Asibi and not by selection of genomes in the wild-type population. Relative quasispecies structure is a plausible correlate of attenuation for live viral vaccines. Analyses such as these of attenuated viruses improve our understanding of the molecular basis of vaccine attenuation and provide critical information on the stability of live vaccines and the risk of reversion to virulence.

  17. Comparative Study on Growth Performance of Transgenic (Over-Expressed OsNHX1 and Wild-Type Nipponbare under Different Salinity Regimes

    Directory of Open Access Journals (Sweden)

    Nurul Kahrani ISHAK

    2015-11-01

    Full Text Available Transgenic Nipponbare which over-expressed a Na+/H+ antiporter gene OsNHX1 was used to compare its growth performance, water status and photosynthetic efficiency with its wild type under varying salinity regimes. Chlorophyll content, quantum yield and photosynthetic rate were measured to assess the impact of salinity stress on photosynthetic efficiency for transgenic and wild-type Nipponbare. Effects of salinity on water status and gas exchange to both lines were studied by measuring water use efficiency, instantaneous transpiration rate and stomatal conductance. Dry shoot weight and leaf area were determined after three months of growth to assess the impacts of salinity on the growth of those two lines. Our study showed that both lines were affected by salinity stress, however, the transgenic line showed higher photosynthetic efficiency, better utilization of water, and better growth due to low transpiration rate and stomatal conductance. Reduction of photosynthetic efficiency exhibited by the wild-type Nipponbare was correlated to its poor growth under salinity stress.

  18. [Multilocus sequence-typing for characterization of Moscow strains of Haemophilus influenzae type b].

    Science.gov (United States)

    Platonov, A E; Mironov, K O; Iatsyshina, S B; Koroleva, I S; Platonova, O V; Gushchin, A E; Shipulin, G A

    2003-01-01

    Haemophilius influenzae, type b (Hib) bacteria, were genotyped by multilocus sequence typing (MLST) using 5 loci (adk, fucK, mdh, pgi, recA). 42 Moscow Hib strains (including 38 isolates form cerebrospinal fluid of children, who had purulent meningitis in 1999-2001, and 4 strains isolated from healthy carriers of Hib), as well as 2 strains from Yekaterinburg were studied. In MLST a strain is characterized, by alleles and their combinations (an allele profile) referred to also as sequence-type (ST). 9 Sts were identified within the Russian Hib bacteria: ST-1 was found in 25 strains (57%), ST-12 was found in 8 strains (18%), ST-11 was found in 4 strains (9%) and ST-15 was found in 2 strains (4.5%); all other STs strains (13, 14, 16, 17, 51) were found in isolated cases (2.3%). A comparison of allelic profiles and of nucleotide sequences showed that 93% of Russian isolates, i.e. strain with ST-1, 11, 12, 13, 15 and 17, belong to one and the same clonal complex. 2 isolates from Norway and Sweden from among 7 foreign Hib strains studied up to now can be described as belonging to the same clonal complex; 5 Hib strains were different from the Russian ones.

  19. Monoclonal antibodies to polioviruses; comparison of intratypic strain differentiation of poliovirus type 1 using monoclonal antibodies versus cross-absorbed antisera.

    NARCIS (Netherlands)

    A.D.M.E. Osterhaus (Albert); A.L. van Wezel; T.G. Hazendonk; F.G.C.M. Uytdehaag (Fons); J.A.A.M. van Asten (Jack); G. van Steenis (Bert)

    1983-01-01

    textabstractA panel of 10 monoclonal antibodies raised to 3 different poliovirus type 1 strains was tested in a micro-enzyme-linked immunosorbent assay and in a micro-neutralization test against 87 poliovirus type 1 strains. The results, evaluated in a newly developed system for intratypic strain

  20. Inherited and environmentally induced differences in mutation frequencies between wild strains of Sordaria fimicola from "Evolution Canyon".

    Science.gov (United States)

    Lamb, B C; Saleem, M; Scott, W; Thapa, N; Nevo, E

    1998-05-01

    We have studied whether there is natural genetic variation for mutation frequencies, and whether any such variation is environment-related. Mutation frequencies differed significantly between wild strains of the fungus Sordaria fimicola isolated from a harsher or a milder microscale environment in "Evolution Canyon," Israel. Strains from the harsher, drier, south-facing slope had higher frequencies of new spontaneous mutations and of accumulated mutations than strains from the milder, lusher, north-facing slope. Collective total mutation frequencies over many loci for ascospore pigmentation were 2.3, 3.5 and 4.4% for three strains from the south-facing slope, and 0.9, 1.1, 1.2, 1.3 and 1.3% for five strains from the north-facing slope. Some of this between-slope difference was inherited through two generations of selfing, with average spontaneous mutation frequencies of 1.9% for south-facing slope strains and 0.8% for north-facing slope strains. The remainder was caused by different frequencies of mutations arising in the original environments. There was also significant heritable genetic variation in mutation frequencies within slopes. Similar between-slope differences were found for ascospore germination-resistance to acriflavine, with much higher frequencies in strains from the south-facing slope. Such inherited variation provides a basis for natural selection for optimum mutation rates in each environment.

  1. Experimental study of per-rectal portal scintigraphy using 99mTc-HM-PAO

    International Nuclear Information System (INIS)

    Kubota, Hayato; Shinotsuka, Akira; Takenaka, Hiroki; Tamaki, Satoshi.

    1994-01-01

    Usefulness of per-rectal portal scintigraphy by 123 I-IMP has already been admitted. We assessed whether 99m Tc-HM-PAO, another agent used for cerebral blood flow scintigraphy, could be utilized for scintigraphic evaluation of the portal system. Animal experiments were carried out to evaluate the usefulness of the examination. Shunt indices obtained from per-rectal portal scintigraphy by 123 I-IMP and 99m Tc-HM-PAO in shunt models and shunt rate obtained by direct injection of 99m Tc-MAA into the inferior mesenteric vein under laparotomy were compared. Correlation coefficient of each agent with 99m Tc-MAA was 0.90 for 99m Tc-HM-PAO and 0.80 for 123 I-IMP. It was also noted that as larger quantity of the tracer could be administered in 99m Tc-HM-PAO than in 123 I-IMP, absorption from rectum was optimum and liver extraction fraction was 94.4%. Therefore, we concluded that 99m Tc-HM-PAO was useful for per-rectal portal scintigraphy. (author)

  2. Identifying the Integrated Neural Networks Involved in Capsaicin-Induced Pain Using fMRI in Awake TRPV1 Knockout and Wild-Type Rats

    Directory of Open Access Journals (Sweden)

    Jason Richard Yee

    2015-02-01

    Full Text Available In the present study, we used functional MRI in awake rats to investigate the pain response that accompanies intradermal injection of capsaicin into the hindpaw. To this end, we used BOLD imaging together with a 3D segmented, annotated rat atlas and computational analysis to identify the integrated neural circuits involved in capsaicin-induced pain. The specificity of the pain response to capsaicin was tested in a transgenic model that contains a biallelic deletion of the gene encoding for the transient receptor potential cation channel subfamily V member 1 (TRPV1. Capsaicin is an exogenous ligand for the TRPV1 receptor, and in wild-type rats, activated the putative pain neural circuit. In addition, capsaicin-treated wild-type rats exhibited activation in brain regions comprising the Papez circuit and habenular system, systems that play important roles in the integration of emotional information, and learning and memory of aversive information, respectively. As expected, capsaicin administration to TRPV1-KO rats failed to elicit the robust BOLD activation pattern observed in wild-type controls. However, the intradermal injection of formalin elicited a significant activation of the putative pain pathway as represented by such areas as the anterior cingulate, somatosensory cortex, parabrachial nucleus, and periaqueductal gray. Notably, comparison of neural responses to capsaicin in wild-type versus knock-out rats uncovered evidence that capsaicin may function in an antinociceptive capacity independent of TRPV1 signaling. Our data suggest that neuroimaging of pain in awake, conscious animals has the potential to inform the neurobiological basis of full and integrated perceptions of pain.

  3. The Effects of Chinese Herbal Medicines on the Quorum Sensing-Regulated Virulence in Pseudomonas aeruginosa PAO1

    Directory of Open Access Journals (Sweden)

    Yee Meng Chong

    2018-04-01

    Full Text Available The quorum sensing (QS system has been used by many opportunistic pathogenic bacteria to coordinate their virulence determinants in relation to cell-population density. As antibiotic-resistant bacteria are on the rise, interference with QS has been regarded as a novel way to control bacterial infections. As such, many plant-based natural products have been widely explored for their therapeutic roles. These natural products may contain anti-QS compounds that could block QS signals generation or transmission to combat QS pathogens. In this study, we report the anti-QS activities of four different Chinese herbal plant extracts: Poria cum Radix pini, Angelica dahurica, Rhizoma cibotii and Schizonepeta tenuifolia, on Pseudomonas aeruginosa PAO1. All the plants extracted using hexane, chloroform and methanol were tested and found to impair swarming motility and pyocyanin production in P. aeruginosa PAO1, particularly by Poria cum Radix pini. In addition, all the plant extracts also inhibited violacein production in C. violaceum CV026 up to 50% while bioluminescence activities were reduced in lux-based E. coli biosensors, pSB401 and pSB1075, up to about 57%. These anti-QS properties of the four medicinal plants are the first documentation that demonstrates a potential approach to attenuate pathogens’ virulence determinants.

  4. Use of tissue-specific microRNA to control pathology of wild-type adenovirus without attenuation of its ability to kill cancer cells.

    Science.gov (United States)

    Cawood, Ryan; Chen, Hannah H; Carroll, Fionnadh; Bazan-Peregrino, Miriam; van Rooijen, Nico; Seymour, Leonard W

    2009-05-01

    Replicating viruses have broad applications in biomedicine, notably in cancer virotherapy and in the design of attenuated vaccines; however, uncontrolled virus replication in vulnerable tissues can give pathology and often restricts the use of potent strains. Increased knowledge of tissue-selective microRNA expression now affords the possibility of engineering replicating viruses that are attenuated at the RNA level in sites of potential pathology, but retain wild-type replication activity at sites not expressing the relevant microRNA. To assess the usefulness of this approach for the DNA virus adenovirus, we have engineered a hepatocyte-safe wild-type adenovirus 5 (Ad5), which normally mediates significant toxicity and is potentially lethal in mice. To do this, we have included binding sites for hepatocyte-selective microRNA mir-122 within the 3' UTR of the E1A transcription cassette. Imaging versions of these viruses, produced by fusing E1A with luciferase, showed that inclusion of mir-122 binding sites caused up to 80-fold decreased hepatic expression of E1A following intravenous delivery to mice. Animals administered a ten-times lethal dose of wild-type Ad5 (5x10(10) viral particles/mouse) showed substantial hepatic genome replication and extensive liver pathology, while inclusion of 4 microRNA binding sites decreased replication 50-fold and virtually abrogated liver toxicity. This modified wild-type virus retained full activity within cancer cells and provided a potent, liver-safe oncolytic virus. In addition to providing many potent new viruses for cancer virotherapy, microRNA control of virus replication should provide a new strategy for designing safe attenuated vaccines applied across a broad range of viral diseases.

  5. Molecular typing of Brucella melitensis endemic strains and differentiation from the vaccine strain Rev-1.

    Science.gov (United States)

    Noutsios, Georgios T; Papi, Rigini M; Ekateriniadou, Loukia V; Minas, Anastasios; Kyriakidis, Dimitrios A

    2012-03-01

    In the present study forty-four Greek endemic strains of Br. melitensis and three reference strains were genotyped by Multi locus Variable Number Tandem Repeat (ML-VNTR) analysis based on an eight-base pair tandem repeat sequence that was revealed in eight loci of Br. melitensis genome. The forty-four strains were discriminated from the vaccine strain Rev-1 by Restriction Fragment Length Polymorphism (RFLP) and Denaturant Gradient Gel Electrophoresis (DGGE). The ML-VNTR analysis revealed that endemic, reference and vaccine strains are genetically closely related, while most of the loci tested (1, 2, 4, 5 and 7) are highly polymorphic with Hunter-Gaston Genetic Diversity Index (HGDI) values in the range of 0.939 to 0.775. Analysis of ML-VNTRs loci stability through in vitro passages proved that loci 1 and 5 are non stable. Therefore, vaccine strain can be discriminated from endemic strains by allele's clusters of loci 2, 4, 6 and 7. RFLP and DGGE were also employed to analyse omp2 gene and reveled different patterns among Rev-1 and endemic strains. In RFLP, Rev-1 revealed three fragments (282, 238 and 44 bp), while endemic strains two fragments (238 and 44 bp). As for DGGE, the electrophoretic mobility of Rev-1 is different from the endemic strains due to heterologous binding of DNA chains of omp2a and omp2b gene. Overall, our data show clearly that it is feasible to genotype endemic strains of Br. melitensis and differentiate them from vaccine strain Rev-1 with ML-VNTR, RFLP and DGGE techniques. These tools can be used for conventional investigations in brucellosis outbreaks.

  6. Antigenic characterization of a formalin-inactivated poliovirus vaccine derived from live-attenuated Sabin strains.

    Science.gov (United States)

    Tano, Yoshio; Shimizu, Hiroyuki; Martin, Javier; Nishimura, Yorihiro; Simizu, Bunsiti; Miyamura, Tatsuo

    2007-10-10

    A candidate inactivated poliovirus vaccine derived from live-attenuated Sabin strains (sIPV), which are used in the oral poliovirus vaccine (OPV), was prepared in a large-production scale. The modification of viral antigenic epitopes during the formalin inactivation process was investigated by capture ELISA assays using type-specific and antigenic site-specific monoclonal antibodies (MoAbs). The major antigenic site 1 was modified during the formalin inactivation of Sabin 1. Antigenic sites 1-3 were slightly modified during the formalin inactivation of Sabin 2 strain. Sites 1 and 3 were altered on inactivated Sabin 3 virus. These alterations were different to those shown by wild-type Saukett strain, used in conventional IPV (cIPV). It has been previously reported that type 1 sIPV showed higher immunogenicity to type 1 cIPV whereas types 2 and 3 sIPV induced lower level of immunogenicity than their cIPV counterparts. Our results suggest that the differences in epitope structure after formalin inactivation may account, at least in part, for the observed differences in immunogenicity between Sabin and wild-type inactivated poliovaccines.

  7. Ellagic acid derivatives from Terminalia chebula Retz. downregulate the expression of quorum sensing genes to attenuate Pseudomonas aeruginosa PAO1 virulence.

    Directory of Open Access Journals (Sweden)

    Sajal Sarabhai

    Full Text Available BACKGROUND: Burgeoning antibiotic resistance in Pseudomonas aeruginosa has necessitated the development of anti pathogenic agents that can quench acylhomoserine lactone (AHL mediated QS with least risk of resistance. This study explores the anti quorum sensing potential of T. chebula Retz. and identification of probable compounds(s showing anti QS activity and the mechanism of attenuation of P. aeruginosa PAO1 virulence factors. METHODS AND RESULTS: Methanol extract of T. chebula Retz. fruit showed anti QS activity using Agrobacterium tumefaciens A136. Bioactive fraction (F7, obtained by fractionation of methanol extract using Sephadex LH20, showed significant reduction (p<0.001 in QS regulated production of extracellular virulence factors in P. aeruginosa PAO1. Biofilm formation and alginate were significantly (p<0.05 reduced with enhanced (20% susceptibility to tobramycin. Real Time PCR of F7 treated P. aeruginosa showed down regulation of autoinducer synthase (lasI and rhlI and their cognate receptor (lasR and rhlR genes by 89, 90, 90 and 93%, respectively. Electrospray Ionization Mass Spectrometry also showed 90 and 64% reduction in the production of 3-oxo-C(12HSL and C(4HSL after treatment. Decrease in AHLs as one of the mechanisms of quorum quenching by F7 was supported by the reversal of inhibited swarming motility in F7-treated P. aeruginosa PAO1 on addition of C(4HSL. F7 also showed antagonistic activity against 3-oxo-C(12HSL-dependent QS in E. coli bioreporter. C. elegans fed on F7-treated P. aeruginosa showed enhanced survival with LT50 increasing from 24 to 72 h. LC-ESI-MS of F7 revealed the presence of ellagic acid derivatives responsible for anti QS activity in T. chebula extract. CONCLUSIONS: This is the first report on anti QS activity of T. chebula fruit linked to EADs which down regulate the expression of lasIR and rhlIR genes with concomitant decrease in AHLs in P. aeruginosa PAO1 causing attenuation of its virulence factors

  8. Common variants of the BRCA1 wild-type allele modify the risk of breast cancer in BRCA1 mutation carriers.

    OpenAIRE

    Cox, D. G.; Simard, J.; Sinnett, D.; Hamdi, Y.; Soucy, P.; Ouimet, M.; Barjhoux, L.; Verny-Pierre, C.; McGuffog, L.; Healey, S.; Szabo, C.; Greene, M. H.; Mai, P. L.; Andrulis, I. L.; Thomassen, M.

    2011-01-01

    Mutations in the BRCA1 gene substantially increase a woman's lifetime risk of breast cancer. However, there is great variation in this increase in risk with several genetic and non-genetic modifiers identified. The BRCA1 protein plays a central role in DNA repair, a mechanism that is particularly instrumental in safeguarding cells against tumorigenesis. We hypothesized that polymorphisms that alter the expression and/or function of BRCA1 carried on the wild-type (non-mutated) copy of the BRCA...

  9. Antibiotic resistance in Pseudomonas aeruginosa strains with increased mutation frequency due to inactivation of the DNA oxidative repair system

    DEFF Research Database (Denmark)

    Mandsberg, Lotte F; Ciofu, Oana; Kirkby, N

    2009-01-01

    ,8-dihydro-8-oxodeoxyguanosine) than PAO1 after exposure to PMNs, and they developed resistance to antibiotics more frequently. The mechanisms of resistance were increased β-lactamase production and overexpression of the MexCD-OprJ efflux-pump. Mutations in either the mutT or the mutY gene were found...... in resistant HP clinical isolates from patients with CF, and complementation with wild-type genes reverted the phenotype. In conclusion, oxidative stress might be involved in the development of resistance to antibiotics. We therefore suggest the possible use of antioxidants for CF patients to prevent...

  10. [Formation of the Pseudomonas aeruginosa PAO1 biofilms in the presence of hydrogen peroxide; the effect of the AiiA gene].

    Science.gov (United States)

    Pliuta, V A; Andreenko, Iu V; Kuznetsov, A E; Khmel', I A

    2013-01-01

    In the natural ecosystems, most bacteria exist as specifically organized biofilms attached to various surfaces; the biofilms have a complex architecture and are surrounded by an exopolymeric matrix. The bacteria in the biofilms are extremely resistant to antibacterial agents. The ability of the pathogenic bacteria to produce biofilms causes serious problems in medicine. Therefore, the study of the action of different compounds with antibacterial activity is of great interest. In this work, we studied the effect of the hydrogen peroxide (H2O2) on the formation of biofilms by Pseudomonas aeruginosa PAO1. It was shown that H2O2 in concentrations that do not suppress bacterial growth (or suppress it only weakly) stimulates the formation of the biofilms. At higher concentrations, H2O2 inhibits the formation of the biofilms. In order to determine if the stimulation of the biofilm formation depends on Quorum Sensing (QS) regulation, the plasmid pME6863 containing the heterologous gene aiiA encoding the N-acyl-homoserine lactonase AiiA was introduced into P. aeruginosa PAO1. The synthesis by cells of this enzyme degrading N-acyl-homoserine lactones (AHL), signaling molecules of the QS systems, led to the absence of the stimulation of the biofilm formation by the action of H2O2. This fact indicates that the stimulation of the biofilm formation in the presence of H2O2 depends on the functioning of the QS systems of the gene expression regulation of P. aeruginosa PAO1.

  11. Different action of MMS and EMS in UV-sensitive strains of Aspergillus nidulans.

    Science.gov (United States)

    Babudri, N; Politi, M G

    1989-05-01

    The repair of methyl methanesulfonate (MMS) and ethyl methanesulfonate (EMS) damages has been investigated in the fungus Aspergillus nidulans. 4 UV-sensitive mutants, namely uvsB, uvsD, uvsF and uvsH have been tested for their sensitivity and mutability to the above-mentioned agents. The results obtained show that: (1) uvsB and uvsD mutants are no more sensitive than the wild-type strain to the lethal action of EMS. In contrast, they are more sensitive to MMS; (2) uvsF and uvsH mutants are more sensitive than the wild type to EMS at 37 degrees C but not at 20 degrees C. However, they are more sensitive than the wild type to MMS at 37 degrees C as well as at 20 degrees C; (3) the mutation frequencies after treatment with either MMS or EMS plotted against survival are not altered in the UV-sensitive strains compared to the wild-type strain. From these data it may be concluded that the repair of lethal lesions induced by ethylating and methylating agents is under the control of different pathways. Furthermore the mutants tested are not involved in the mutagenic process.

  12. Pulmonary hypertension in wild type mice and animals with genetic deficit in KCa2.3 and KCa3.1 channels.

    Directory of Open Access Journals (Sweden)

    Christine Wandall-Frostholm

    Full Text Available In vascular biology, endothelial KCa2.3 and KCa3.1 channels contribute to arterial blood pressure regulation by producing membrane hyperpolarization and smooth muscle relaxation. The role of KCa2.3 and KCa3.1 channels in the pulmonary circulation is not fully established. Using mice with genetically encoded deficit of KCa2.3 and KCa3.1 channels, this study investigated the effect of loss of the channels in hypoxia-induced pulmonary hypertension.Male wild type and KCa3.1-/-/KCa2.3T/T(+DOX mice were exposed to chronic hypoxia for four weeks to induce pulmonary hypertension. The degree of pulmonary hypertension was evaluated by right ventricular pressure and assessment of right ventricular hypertrophy. Segments of pulmonary arteries were mounted in a wire myograph for functional studies and morphometric studies were performed on lung sections. Chronic hypoxia induced pulmonary hypertension, right ventricular hypertrophy, increased lung weight, and increased hematocrit levels in either genotype. The KCa3.1-/-/KCa2.3T/T(+DOX mice developed structural alterations in the heart with increased right ventricular wall thickness as well as in pulmonary vessels with increased lumen size in partially- and fully-muscularized vessels and decreased wall area, not seen in wild type mice. Exposure to chronic hypoxia up-regulated the gene expression of the KCa2.3 channel by twofold in wild type mice and increased by 2.5-fold the relaxation evoked by the KCa2.3 and KCa3.1 channel activator NS309, whereas the acetylcholine-induced relaxation - sensitive to the combination of KCa2.3 and KCa3.1 channel blockers, apamin and charybdotoxin - was reduced by 2.5-fold in chronic hypoxic mice of either genotype.Despite the deficits of the KCa2.3 and KCa3.1 channels failed to change hypoxia-induced pulmonary hypertension, the up-regulation of KCa2.3-gene expression and increased NS309-induced relaxation in wild-type mice point to a novel mechanism to counteract pulmonary

  13. Complete genome sequence of 'Thermobaculum terrenum' type strain (YNP1).

    Science.gov (United States)

    Kiss, Hajnalka; Cleland, David; Lapidus, Alla; Lucas, Susan; Del Rio, Tijana Glavina; Nolan, Matt; Tice, Hope; Han, Cliff; Goodwin, Lynne; Pitluck, Sam; Liolios, Konstantinos; Ivanova, Natalia; Mavromatis, Konstantinos; Ovchinnikova, Galina; Pati, Amrita; Chen, Amy; Palaniappan, Krishna; Land, Miriam; Hauser, Loren; Chang, Yun-Juan; Jeffries, Cynthia D; Lu, Megan; Brettin, Thomas; Detter, John C; Göker, Markus; Tindall, Brian J; Beck, Brian; McDermott, Timothy R; Woyke, Tanja; Bristow, James; Eisen, Jonathan A; Markowitz, Victor; Hugenholtz, Philip; Kyrpides, Nikos C; Klenk, Hans-Peter; Cheng, Jan-Fang

    2010-10-27

    'Thermobaculum terrenum' Botero et al. 2004 is the sole species within the proposed genus 'Thermobaculum'. Strain YNP1(T) is the only cultivated member of an acid tolerant, extremely thermophilic species belonging to a phylogenetically isolated environmental clone group within the phylum Chloroflexi. At present, the name 'Thermobaculum terrenum' is not yet validly published as it contravenes Rule 30 (3a) of the Bacteriological Code. The bacterium was isolated from a slightly acidic extreme thermal soil in Yellowstone National Park, Wyoming (USA). Depending on its final taxonomic allocation, this is likely to be the third completed genome sequence of a member of the class Thermomicrobia and the seventh type strain genome from the phylum Chloroflexi. The 3,101,581 bp long genome with its 2,872 protein-coding and 58 RNA genes is a part of the Genomic Encyclopedia of Bacteria and Archaea project.

  14. Evaluating the use of PAO (4 cSt polyalphaoelfin) oil instead of DOP (di-octyl phthalate) oil for measuring the aerosol capture of nuclear canister filters

    Energy Technology Data Exchange (ETDEWEB)

    Moore, Murray E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-07-18

    This document details the distinction between using PAO (4 cSt polyalphaoelfin) oil instead of DOP (di-octyl phthalate) oil for measuring the aerosol capture of filters. This document is developed to justify the use of PAO rather than DOP for evaluating the performance of filters in the SAVY 4000 and Hagan containers. The design criteria (Anderson et al, 2012) for purchasing SAVY 4000 containers and the Safety Analysis Report for the SAVY 4000 Container Series specified that the filter must “capture greater than 99.97% of 0.45 μm mean diameter dioctyl phthalate (DOP) aerosol at the rated flow with a DOP concentration of 65±15 micrograms per liter.”This corresponds to a leakage percent of 0.03% (3.0x10-2). The density of DOP oil is 985 kg/m3 and the density of PAO oil is 819 kg/m3. ATI Test Inc measured the mass mean diameter of aerosol distributions produced by a single Laskin type III-A nozzle operating at a 20 psig air pressure as 0.563 μm for DOP oil and 0.549 μm for PAO oil. (See Appendix A.) For both types of oil in this document, the single fiber method calculated the leakage percent to be 4.4x10-5 for DOP oil and 4.7x10-5 for PAO oil. Although the percent error between these two quantities is 7.7%, these calculated leakage percent values are more than two orders of magnitude less than the criterion specified in the SAVY canister SAR. As a point of reference, the photometer used to measure the SAVY canister filter performance cannot resolve values for the leakage percent below 1.0x10-5. Additionally, over a range of particle sizes from 0.01 μm to 3.0 μm, there was less than 4.0x10-5 error between the calculated filter efficiency for the two types of oil at any particular particle size diameter. In conclusion, the difference between using DOP and PAO for testing SAVY canister filters is of inconsequential concern.

  15. Distinct virulence of Rift Valley fever phlebovirus strains from different genetic lineages in a mouse model.

    Directory of Open Access Journals (Sweden)

    Tetsuro Ikegami

    Full Text Available Rift Valley fever phlebovirus (RVFV causes high rates of abortions and fetal malformations in ruminants, and hemorrhagic fever, encephalitis, or blindness in humans. Viral transmission occurs via mosquito vectors in endemic areas, which necessitates regular vaccination of susceptible livestock animals to prevent the RVF outbreaks. Although ZH501 strain has been used as a challenge strain for past vaccine efficacy studies, further characterization of other RVFV strains is important to optimize ruminant and nonhuman primate RVFV challenge models. This study aimed to characterize the virulence of wild-type RVFV strains belonging to different genetic lineages in outbred CD1 mice. Mice were intraperitoneally infected with 1x103 PFU of wild-type ZH501, Kenya 9800523, Kenya 90058, Saudi Arabia 200010911, OS1, OS7, SA75, Entebbe, or SA51 strains. Among them, mice infected with SA51, Entebbe, or OS7 strain showed rapid dissemination of virus in livers and peracute necrotic hepatitis at 2-3 dpi. Recombinant SA51 (rSA51 and Zinga (rZinga strains were recovered by reverse genetics, and their virulence was also tested in CD1 mice. The rSA51 strain reproduced peracute RVF disease in mice, whereas the rZinga strain showed a similar virulence with that of rZH501 strain. This study showed that RVFV strains in different genetic lineages display distinct virulence in outbred mice. Importantly, since wild-type RVFV strains contain defective-interfering RNA or various genetic subpopulations during passage from original viral isolations, recombinant RVFV strains generated by reverse genetics will be better suitable for reproducible challenge studies for vaccine development as well as pathological studies.

  16. COMPARATIVE ANALYSIS ON PERFORMANCE OF POWER CONVERTERSFOR MPPT USING PAO TECHNIQUE

    OpenAIRE

    Dr. S. Rajeswari*

    2017-01-01

    This research work is mainly spotlight to identify a suitable power converter for tracking the Maximum Power Point, an analysis of MPPT based power converters has been carried out in this work. A PV system is a non-linear power source due to the variations in the climatic conditions, hence tracking the maximum power point is difficult. It mainly explains about the PAO algorithm based MPPT method to track the maximum power. It also discuss about different types of conventional power converters...

  17. The vaccine properties of a Brazilian bovine herpesvirus 1 strain with an induced deletion of the gE gene

    International Nuclear Information System (INIS)

    Franco, A.C.; Spilki, F.R.; Roehe, P.M.; Rijsewijk, F.A.M.

    2005-01-01

    Aiming at the development of a differential vaccine (DIVA) against infectious bovine rhinotracheitis (IBR), a Brazilian strain of bovine herpesvirus type 1 (BHV1) with a deletion of the glycoprotein E (gE) gene was constructed (265gE - ). Here we present the experiments performed with this strain in order to evaluate its safety and efficacy as a vaccine virus in cattle. In the first experiment, a group of calves was inoculated with 265gE - and challenged with wild type virus 21 days post-inoculation. Calves immunized with 265gE - virus and challenged with wild type virus developed very mild clinical disease with a significant reduction in the amount of virus excretion and duration. The safety of the 265gE - during pregnancy was assessed using 22 pregnant cows, at different stages of gestation, that were inoculated with the 265gE - virus intramuscularly, with 15 pregnant cows kept as non-vaccinated controls. No abortions, stillbirths or foetal abnormalities were seen after vaccination. The results show that the 265gE - recombinant is attenuated and able to prevent clinical disease upon challenge. This recombinant will be further evaluated as a candidate virus for a BHV1 differential vaccine. (author)

  18. Multilocus sequence typing of commensal and enteropathogenic Escherichia coli from domestic and wild lagomorphs in Italy

    Directory of Open Access Journals (Sweden)

    Giorgia Dotto

    2015-12-01

    Full Text Available The aim of the study was to determine the multilocus sequence types of Escherichia coli from diseased farm rabbits and apparently healthy wild lagomorphs, and the genetic relatedness among them. Fifty-five enteropathogenic E. coli from reared rabbits and 32 from wild rabbits and hares were characterised by multilocus sequence typing (MLST according to the Michigan State University EcMLST scheme. Isolates were differentiated into 37 sequence types (STs, which were grouped into 8 clonal complexes (CCs. The most common ST was ST140 (CC31, followed by ST238 and ST119 (CC17. MLST analysis revealed 22 novel STs. Phylogenetic analyses showed a heterogeneous distribution of STs into 3 clusters of genetically related strains. The genetic relationship among STs of different origin and the detection of new, as well as previously described STs as human pathogens, indicate a widespread distribution and adaptability of particular lineages to different hosts. These findings highlight the need for further research to improve the knowledge about E. coli populations colonising the gut of lagomorphs and their zoonotic potential.

  19. Origin and characteristics of Pseudomonas aeruginosa PAO1 clones surviving after the induction of transposable prophages

    Energy Technology Data Exchange (ETDEWEB)

    Krylov, V.N.; Solov`era, T.I.; Burkal`tseva, M.V. [State Research Institute of Genetics and Selection of Industrial Microorganisms, Moscow (Russian Federation)] [and others

    1995-08-01

    Various mutations cancelling the lethal effect of phage lytic development and simultaneous phenotypic modifications were found in rare clones surviving after incubation at 42{degrees}C of Pseudomonas aeruginosa (D3112 cts15), lysogenic for thermoinducible mutant cts15 of the transposable prophage (TP) D3112. All mutations arose prior to thermal induction. Temperature induction of other bacteriophages (nontransposable) did not lead to selection of bacterial morphological mutants. Therefore, it was concluded that mutagenesis occurred upon the partial (reversible) TP derepression accompanied by coupled replication-transposition of TP, the latter being the direct cause of the mutator effect. Isolation of the P. aeruginosa PAO1 mutant R10 (this mutant is resistant to infection with TP at 42{degrees}C) allowed the proper selection and examination of numerous survivors. Comparison of their types derived from lysogens with different prophage location indicated that the number of secondary sites where TP integration is possible without the loss of cell viability is limited. Several transposition events occurred in the history of some survivors (during a repeated or single derepression event). Type D clones, which produce small colonies, are of special interest, because mechanisms underlying the survival of such clones are extremely diverse, and their phenotypes indicate the possibility of stable chromosomal rearrangements in the genome of P. aeruginosa. 16 refs., 2 figs., 2 tabs.

  20. Establishment of New Transmissible and Drug-Sensitive Human Immunodeficiency Virus Type 1 Wild Types due to Transmission of Nucleoside Analogue-Resistant Virus

    NARCIS (Netherlands)

    Ronde, Anthony de; Dooren, Maaike van; Hoek, Lian van der; Bouwhuis, Denise; Rooij, Esther de; Gemen, Bob van; Boer, R.J. de; Goudsmit, Jaap

    2000-01-01

    Sequence analysis of human immunodeficiency virus type 1 (HIV-1) from 74 persons with acute infections identified eight strains with mutations in the reverse transcriptase (RT) gene at positions 41, 67, 68, 70, 215, and 219 associated with resistance to the nucleoside analogue zidovudine (AZT).

  1. Establishment of new transmissible and drug-sensitive human immunodeficiency virus type 1 wild types due to transmission of nucleoside analogue-resistant virus

    NARCIS (Netherlands)

    de Ronde, A.; van Dooren, M.; van der Hoek, L.; Bouwhuis, D.; de Rooij, E.; van Gemen, B.; de Boer, R.; Goudsmit, J.

    2001-01-01

    Sequence analysis of human immunodeficiency virus type 1 (HIV-1) from 74 persons with acute infections identified eight strains with mutations in the reverse transcriptase (RT) gene at positions 41, 67, 68, 70, 215, and 219 associated with resistance to the nucleoside analogue zidovudine (AZT).

  2. [Changes of biological behavioral of E. coli K1 after ppk1 gene deletion].

    Science.gov (United States)

    Peng, Liang; Pan, Jiayun; Luo, Su; Yang, Zhenghui; Huang, Mufang; Cao, Hong

    2014-06-01

    To study the changes in biological behaviors of meningitis E. coli K1 strain E44 after deletion of polyphosphate kinase 1 (ppk1) gene and explore the role of ppk1 in the pathogenesis of E. coli K1-induced meningitis. The wild-type strain E. coli K1 and ppk1 deletion mutant were exposed to heat at 56 degrees celsius; for 6 min, and their survival rates were determined. The adhesion and invasion of the bacteria to human brain microvascular endothelial cells (HBMECs) were observed using electron microscopy and quantitative tests. HBMECs were co-incubated with wild-type strain or ppk1 deletion mutant, and the cytoskeleton rearrangement was observed under laser scanning confocal microscope. The survival rate of the ppk1 deletion mutant was significantly lower than that of the wild-type strain after heat exposure. The ppk1 deletion mutant also showed lowered cell adhesion and invasion abilities and weakened ability to induce cytoskeleton rearrangement in HBMECs. ppk1 gene is important for E.coli K1 for heat resistance, cell adhesion and invasion, and for inducing cytoskeletal rearrangement in HBMECs.

  3. Electrotransformation and expression of cellulase genes in wild-type Lactobacillus reuteri.

    Science.gov (United States)

    Li, Wang; Yang, Ming-Ming; Zhang, Guang-Qin; He, Wan-Ling; Li, Yuan-Xiao; Chen, Yu-Lin

    2012-01-01

    Two cellulase genes, Cel15 and Cel73, were amplified from Bacillus subtilis genome DNA in a previous study. Two integrative vectors, pLEM4153 and pLEM4154, containing the genes Cel15 and Cel73, respectively, were constructed and successfully electroporated into the wild-type Lactobacillus reuteri which was isolated from chick guts through an optimized procedure. Two recombinant L. reuteri were selected from a Man, Rogosa, and Sharp (MRS) plate with 10 µg/ml erythromycin, and named L. reuteri XNY-Cel15 and L. reuteri XNY-Cel73, respectively. To verify the transcription and expression of the two cellulase genes in the recombinant L. reuteri strains, the mRNA relative quantity (RQ) and the cellulase activity were determined. The mRNA RQ of Cel15 in L. reuteri XNY-Cel15 is 1,8849.5, and that of Cel73 in L. reuteri XNY-Cel73 is 1,388, and the cellulase activity of the modified MRS broth cultured with L. reuteri XNY-Cel15 was 0.158 U/ml, whereas that with L. reuteri XNY-Cel73 was 0.15 U/ml. Copyright © 2012 S. Karger AG, Basel.

  4. Single photon emission computed tomography with [[sup 99]Tc]-HM-PAO and [[sup 123]I]-IBZM in Alzheimer's disease and dementia of frontal type; Preliminary results

    Energy Technology Data Exchange (ETDEWEB)

    Frisoni, G.B.; Bianchetti, A.; Trabucchi, M. (Alzheimer' s Disease Care Unit, Ist. S. Cuore-FBF, Brescia (Italy)); Pizzolato, G.; Battistin, L. (Neurology Clinic, University Padua, Padua (Italy)); Chierichetti, F.; Ferlin, G. (Nuclear Medicine, Castelfranco Veneto Hospital, Treviso (Italy))

    1994-03-01

    Dementia of frontal type (DFT) is a fairly common degenerative disease distinct from Alzheimer's disease (AD), whose reportedly distinctive instrumental feature is frontal lobe hypoperfusion on SPECT. We evaluated the cortical dopaminergic system in 6AD, 5 DFT, and 6 control subjects with SPECT and both [[sup 99]Tc]-HM-PAO, a perfusion tracer, and [[sup 123]I]-IBZM, a D2 postsynaptic ligand. Both in AD and DFT patients, [[sup 99]Tc]-HM-PAO SPECT showed a relative frontal hypoperfusion. On the contrary, [[sup 123]I]-IBZM SPECT showed significantly reduced ligand uptake in superior frontal regions of DFT (0.89 [+-] 0.08 relative to control subjects) as compared to AD patients (0.97 [+-] 0.02; difference of means: 0.08, 95% confidence Interval 0.004 to 0.156; p = 0.041). Results suggest more marked involvement of the frontal cortical dopaminergic system in DFT than in AD patients. (au) (24 refs.).

  5. Dietary Calcium and Dairy Modulation of Oxidative Stress and Mortality in aP2-Agouti and Wild-type Mice

    Directory of Open Access Journals (Sweden)

    Antje Bruckbauer

    2009-08-01

    Full Text Available Oxidative and inflammatory stress have been implicated as major contributors to the aging process. Dietary Ca reduced both factors in short-term interventions, while milk exerted a greater effect than supplemental Ca. In this work, we examined the effects of life-long supplemental and dairy calcium on lifespan and life-span related biomarkers in aP2-agouti transgenic (model of diet-induced obesity and wild-type mice fed obesigenic diets until their death. These data demonstrate that dairy Ca exerts sustained effects resulting in attenuated adiposity, protection against age-related muscle loss and reduction of oxidative and inflammatory stress in both mouse strains. Although these effects did not alter maximum lifespan, they did suppress early mortality in wild-type mice, but not in aP2-agouti transgenic mice.

  6. Overexpression of wild-type aspartokinase increases L-lysine production in the thermotolerant methylotrophic bacterium Bacillus methanolicus.

    Science.gov (United States)

    Jakobsen, Oyvind M; Brautaset, Trygve; Degnes, Kristin F; Heggeset, Tonje M B; Balzer, Simone; Flickinger, Michael C; Valla, Svein; Ellingsen, Trond E

    2009-02-01

    Aspartokinase (AK) controls the carbon flow into the aspartate pathway for the biosynthesis of the amino acids l-methionine, l-threonine, l-isoleucine, and l-lysine. We report here the cloning of four genes (asd, encoding aspartate semialdehyde dehydrogenase; dapA, encoding dihydrodipicolinate synthase; dapG, encoding AKI; and yclM, encoding AKIII) of the aspartate pathway in Bacillus methanolicus MGA3. Together with the known AKII gene lysC, dapG and yclM form a set of three AK genes in this organism. Overexpression of dapG, lysC, and yclM increased l-lysine production in wild-type B. methanolicus strain MGA3 2-, 10-, and 60-fold (corresponding to 11 g/liter), respectively, without negatively affecting the specific growth rate. The production levels of l-methionine (less than 0.5 g/liter) and l-threonine (less than 0.1 g/liter) were low in all recombinant strains. The AK proteins were purified, and biochemical analyses demonstrated that they have similar V(max) values (between 47 and 58 micromol/min/mg protein) and K(m) values for l-aspartate (between 1.9 and 5.0 mM). AKI and AKII were allosterically inhibited by meso-diaminopimelate (50% inhibitory concentration [IC(50)], 0.1 mM) and by l-lysine (IC(50), 0.3 mM), respectively. AKIII was inhibited by l-threonine (IC(50), 4 mM) and by l-lysine (IC(50), 5 mM), and this enzyme was synergistically inhibited in the presence of both of these amino acids at low concentrations. The correlation between the impact on l-lysine production in vivo and the biochemical properties in vitro of the individual AK proteins is discussed. This is the first example of improving l-lysine production by metabolic engineering of B. methanolicus and also the first documentation of considerably increasing l-lysine production by overexpression of a wild-type AK.

  7. 99mTc HM-PAO brain perfusion SPECT in brain death

    International Nuclear Information System (INIS)

    Bonetti, M.G.; Ciritella, P.; Valle, G.; Perrone, E.

    1995-01-01

    We have easily carried out and interpreted 99m Tc HM-PAO SPECT in a consecutive series of 40 comatose patients with brain damage, without discontinuing therapy. Brain death was diagnosed in 7 patients, by recognising absence of brain perfusion, as shown by no intracranial radionuclide uptake. In patients in whom perfusion was seen on brain scans, HM-PAO SPECT improved assessment of the extent of injury, which in general was larger than suggested by CT. (orig.)

  8. Basic and clinical evaluation of regional cerebral perfusion scintigraphy of 99mTc-HM-PAO

    International Nuclear Information System (INIS)

    Tsukatani, Yasushi; Nakamura, Kayoko; Fujii, Hiroshi

    1988-01-01

    Radiochemical purity of 99m Tc-HM-PAO decreased rapidly after preparation. 99m Tc activity of the whole brain increased rapidly after venous injection, and changed very little after 3 minutes later. 99m Tc-HM-PAO scintigram showed the wider abnormal perfusion area than CT scanning did. Hypoperfusion area found by IMP tended to be wider than that by HM-PAO. There were no side effects observed of all cases. (author)

  9. Production and purification of anti-bacterial biometabolite from wild-type Lactobacillus, isolated from fermented bamboo shoot: future suggestions and a proposed system for secondary metabolite onsite recovery during continuous fermentation.

    Science.gov (United States)

    Badwaik, Laxmikant S; Borah, Pallab Kumar; Deka, Sankar C

    2015-02-01

    Wild-type lactobacillus isolated form Khorisa, a fermented bamboo shoot product of Assam, India were evaluated for production anti-bacterial secondary biometabolites, against Staphylococcus aureus. Submerged fermentation technique was used for the production of secondary anti-microbial biometabolite by a single wild-type lactobacillus strain, which tested positive for the release of anti-bacterial factor(s). Crude cell-free supernatant was obtained, followed by extraction in water-immiscible solvents viz., chloroform, hexane, petroleum ether. Chloroform extract of cell-free crude supernatant showed maximum yield (0.054 g/ml) and inhibited all indicator bacterial strains viz., Escherichia coli, Staphylococcus aureus, and Bacillus cereus. Yields of hexane and petroleum ether extract were 0.052 and 0.026 g/ml, respectively. Minimum lethal dose concentration assay of the chloroform extract showed LDmin values at 27, 1.68, and 1.68 mg/ml for E. coli, S. aureus, and B. cereus, respectively. Kill time for all the indicator bacterial strains were less than 12 h. The efficacy of the anti-bacterial substance seemed to depend on the presence of organic acids, particularly lactic acid. Conceptual-based suggestion for the development of an onsite secondary metabolites recovery system during continuous fermentation has also been attempted.

  10. IncA/C Plasmid Carrying bla(NDM-1), bla(CMY-16), and fosA3 in a Salmonella enterica Serovar Corvallis Strain Isolated from a Migratory Wild Bird in Germany.

    Science.gov (United States)

    Villa, L; Guerra, B; Schmoger, S; Fischer, J; Helmuth, R; Zong, Z; García-Fernández, A; Carattoli, A

    2015-10-01

    A Salmonella enterica serovar Corvallis strain was isolated from a wild bird in Germany. This strain carried the IncA/C2 pRH-1238 plasmid. Complete sequencing of the plasmid was performed, identifying the blaNDM-1, blaCMY-16, fosA3, sul1, sul2, strA, strB, aac(6')-Ib, aadA5, aphA6, tetA(A), mphA, floR, dfrA7, and merA genes, which confer clinically relevant resistance to most of the antimicrobial classes, including β-lactams with carbapenems, fosfomycin, aminoglycosides, co-trimoxazole, tetracyclines, and macrolides. The strain likely originated from the Asiatic region and was transferred to Germany through the Milvus migrans migratory route. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  11. Cross-Regulation between the phz1 and phz2 Operons Maintain a Balanced Level of Phenazine Biosynthesis in Pseudomonas aeruginosa PAO1.

    Directory of Open Access Journals (Sweden)

    Qinna Cui

    Full Text Available Gene duplication often provides selective advantages for the survival of microorganisms in adapting to varying environmental conditions. P. aeruginosa PAO1 possesses two seven-gene operons [phz1 (phzA1B1C1D1E1F1G1 and phz2 (phzA2B2C2D2E2F2G2] that are involved in the biosynthesis of phenazine-1-carboxylic acid and its derivatives. Although the two operons are highly homologous and their functions are well known, it is unclear how the two phz operons coordinate their expressions to maintain the phenazine biosynthesis. By constructing single and double deletion mutants of the two phz operons, we found that the phz1-deletion mutant produced the same or less amount of phenazine-1-carboxylic acid and pyocyanin in GA medium than the phz2-knockout mutant while the phz1-phz2 double knockout mutant did not produce any phenazines. By generating phzA1 and phzA2 translational and transcriptional fusions with a truncated lacZ reporter, we found that the expression of the phz1 operon increased significantly at the post-transcriptional level and did not alter at the transcriptional level in the absence of the phz2 operon. Surprisingly, the expression the phz2 operon increased significantly at the post-transcriptional level and only moderately at the transcriptional level in the absence of the phz1 operon. Our findings suggested that a complex cross-regulation existed between the phz1 and phz2 operons. By mediating the upregulation of one phz operon expression while the other was deleted, this crosstalk would maintain the homeostatic balance of phenazine biosynthesis in P. aeruginosa PAO1.

  12. High-efficiency genome editing and allele replacement in prototrophic and wild strains of Saccharomyces.

    Science.gov (United States)

    Alexander, William G; Doering, Drew T; Hittinger, Chris Todd

    2014-11-01

    Current genome editing techniques available for Saccharomyces yeast species rely on auxotrophic markers, limiting their use in wild and industrial strains and species. Taking advantage of the ancient loss of thymidine kinase in the fungal kingdom, we have developed the herpes simplex virus thymidine kinase gene as a selectable and counterselectable marker that forms the core of novel genome engineering tools called the H: aploid E: ngineering and R: eplacement P: rotocol (HERP) cassettes. Here we show that these cassettes allow a researcher to rapidly generate heterogeneous populations of cells with thousands of independent chromosomal allele replacements using mixed PCR products. We further show that the high efficiency of this approach enables the simultaneous replacement of both alleles in diploid cells. Using these new techniques, many of the most powerful yeast genetic manipulation strategies are now available in wild, industrial, and other prototrophic strains from across the diverse Saccharomyces genus. Copyright © 2014 by the Genetics Society of America.

  13. Production and Its Anti-hyperglycemic Effects of γ-Aminobutyric Acid from the Wild Yeast Strain Pichia silvicola UL6-1 and Sporobolomyces carnicolor 402-JB-1.

    Science.gov (United States)

    Han, Sang-Min; Lee, Jong-Soo

    2017-09-01

    This study was done to produce γ-aminobutyric acid (GABA) from wild yeast as well as investigate its anti-hyperglycemic effects. Among ten GABA-producing yeast strains, Pichia silvicola UL6-1 and Sporobolomyces carnicolor 402-JB-1 produced high GABA concentration of 134.4 µg/mL and 179.2 µg/mL, respectively. P. silvicola UL6-1 showed a maximum GABA yield of 136.5 µg/mL and 200.8 µg/mL from S. carnicolor 402-JB-1 when they were cultured for 30 hr at 30℃ in yeast extract-peptone-dextrose medium. The cell-free extract from P. silvicola UL6-1 and S. carnicolor 402-JB-1 showed very high anti-hyperglycemic α-glucosidase inhibitory activity of 72.3% and 69.9%, respectively. Additionally, their cell-free extract-containing GABA showed the anti-hyperglycemic effect in streptozotocin-induced diabetic Sprague-Dawley rats.

  14. Liver steatosis study_PFAA treated Wild type and PPAR KO mouse data

    Data.gov (United States)

    U.S. Environmental Protection Agency — Data set 1 consists of the experimental data for the Wild Type and PPAR KO animal study and includes data used to prepare Figures 1-4 and Table 1 of the Das et al,...

  15. Esterase activities of intracellular extracts of wild strains of lactic acid bacteria isolated from Serra da Estrela cheese

    OpenAIRE

    Macedo, Angela C.; Tavares, Tânia G.; Malcata, F. Xavier

    2003-01-01

    Lactococcus lactis subsp. lactis strain ESB110019 and Lactobacillus plantarum strain ESB5004, novel strains that were previously isolated from the wild adventitious microflora of certified Serra da Estrela cheeses, were assayed for esterase activity using, as substrates, ortho- and para-nitrophenyl derivatives of fatty acids. Both strains preferentially hydrolyzed short-chain fatty acids; L. lactis ESB110019 exhibited a stronger esterase activity than Lb. plantarum ESB5004 and cleaved the p-n...

  16. Occurrence of Edwardsiella tarda in wild European eels Anguilla anguilla from Mediterranean Spain.

    Science.gov (United States)

    Alcaide, Elena; Herraiz, Sonia; Esteve, Consuelo

    2006-11-21

    Pure cultures of Edwarsiella tarda were isolated from body ulcers and internal organs of wild European eels caught in a Mediterranean freshwater coastal lagoon (Albufera Lake, Valencia, Spain) over a 1 yr period. Overall, the E. tarda isolation rate from wild eels was 9%, but this increased to 22.8% in diseased individuals. All 22 E. tarda isolates belonged to the 'wild-type' biogroup of the species and were virulent for eels (lethal dose that kills 50% of exposed individuals [LD50 dose]: 10(4.85) to 10(6.83) CFU ind.(-1)), and therefore represented the aetiological agent of the haemorrhagic disease observed in wild European eels. The E. tarda isolates and E. tarda CECT 894T type strain were biochemically and serologically related and resistant to macrolides, antifolates, and glycopeptides, but only the isolates from wild eels were resistant to clindamicyn. This study is the first description of edwardsiellosis in a wild European eel population, and alerts us to the presence of E. tarda in natural wetland environments in Mediterranean Europe.

  17. A comparison of the radiosensitivity of stationary, exponential and G1 phase wild type and repair deficient yeast cultures: supporting evidence for stationary phase yeast cells being in G0

    International Nuclear Information System (INIS)

    Tippins, R.S.; Parry, J.M.

    1982-01-01

    The main points to emerge from this comparison of the radiosensitivity of stationary, exponential and G 1 phase yeast cultures were: (1) In wild type yeast cultures, G 1 cells were the most sensitive to the lethal effects of X-rays, exponential phase cells were the most resistant and stationary phase cells were intermediate in sensitivity. (2) With the excision-repair-defective strain D61-3 (rad 3) stationary phase cells were more resistant than exponential cells with G 1 cells again being most sensitive. (3) The rad 50 gene present in JD50 had a marked effect on the X-ray inactivation response of this strain. In the presence of the defective rad 50 allele, exponential phase cells were as sensitive as G 1 phase cells, with stationary phase cells being more resistant than either. (4) There were marked differences in sensitivity between stationary phase and G 1 phase cells. These differences, along with other physiological differences reported by other workers, lead the authors to suggest that stationary phase cells can be better described as being in G 0 phase, i.e. a stage which is outside the normal mitotic cell cycle of an exponential culture. (author)

  18. Differential effects of silver nanoparticles on DNA damage and DNA repair gene expression in Ogg1-deficient and wild type mice.

    Science.gov (United States)

    Nallanthighal, Sameera; Chan, Cadia; Murray, Thomas M; Mosier, Aaron P; Cady, Nathaniel C; Reliene, Ramune

    2017-10-01

    Due to extensive use in consumer goods, it is important to understand the genotoxicity of silver nanoparticles (AgNPs) and identify susceptible populations. 8-Oxoguanine DNA glycosylase 1 (OGG1) excises 8-oxo-7,8-dihydro-2-deoxyguanine (8-oxoG), a pro-mutagenic lesion induced by oxidative stress. To understand whether defects in OGG1 is a possible genetic factor increasing an individual's susceptibly to AgNPs, we determined DNA damage, genome rearrangements, and expression of DNA repair genes in Ogg1-deficient and wild type mice exposed orally to 4 mg/kg of citrate-coated AgNPs over a period of 7 d. DNA damage was examined at 3 and 7 d of exposure and 7 and 14 d post-exposure. AgNPs induced 8-oxoG, double strand breaks (DSBs), chromosomal damage, and DNA deletions in both genotypes. However, 8-oxoG was induced earlier in Ogg1-deficient mice and 8-oxoG levels were higher after 7-d treatment and persisted longer after exposure termination. AgNPs downregulated DNA glycosylases Ogg1, Neil1, and Neil2 in wild type mice, but upregulated Myh, Neil1, and Neil2 glycosylases in Ogg1-deficient mice. Neil1 and Neil2 can repair 8-oxoG. Thus, AgNP-mediated downregulation of DNA glycosylases in wild type mice may contribute to genotoxicity, while upregulation thereof in Ogg1-deficient mice could serve as an adaptive response to AgNP-induced DNA damage. However, our data show that Ogg1 is indispensable for the efficient repair of AgNP-induced damage. In summary, citrate-coated AgNPs are genotoxic in both genotypes and Ogg1 deficiency exacerbates the effect. These data suggest that humans with genetic polymorphisms and mutations in OGG1 may have increased susceptibility to AgNP-mediated DNA damage.

  19. Bio-Engineering High Performance Microbial Strains for MEOR

    Energy Technology Data Exchange (ETDEWEB)

    Xiangdong Fang; Qinghong Wang; Patrick Shuler

    2007-12-30

    The main objectives of this three-year research project are: (1) to employ the latest advances in genetics and bioengineering, especially Directed Protein Evolution technology, to improve the effectiveness of the microbial enhanced oil recovery (MEOR) process. (2) to improve the surfactant activity and the thermal stability of bio-surfactant systems for MEOR; and (3) to develop improved laboratory methods and tools that screen quickly candidate bio-systems for EOR. Biosurfactants have been receiving increasing attention as Enhanced Oil Recovery (EOR) agents because of their unique properties (i.e., mild production conditions, lower toxicity, and higher biodegradability) compared to their synthetic chemical counterparts. Rhamnolipid as a potent natural biosurfactant has a wide range of potential applications, including EOR and bioremediation. During the three-year of the project period, we have successfully cloned the genes involved in the rhamnolipid bio-synthesis. And by using the Transposon containing Rhamnosyltransferase gene rhlAB, we engineered the new mutant strains P. aeruginosa PEER02 and E. coli TnERAB so they can produce rhamnolipid biosurfactans. We were able to produce rhamnolipds in both P. aeroginosa PAO1-RhlA- strain and P. fluorescens ATCC15453 strain, with the increase of 55 to 175 fold in rhamnolipid production comparing with wild type bacteria strain. We have also completed the first round direct evolution studies using Error-prone PCR technique and have constructed the library of RhlAB-containing Transposon to express mutant gene in heterologous hosts. Several methods, such as colorimetric agar plate assay, colorimetric spectrophotometer assay, bioactive assay and oil spreading assay have been established to detect and screen rhamnolipid production. Our engineered P. aeruginosa PEER02 strain can produce rhamnolipids with different carbon sources as substrate. Interfacial tension analysis (IFT) showed that different rhamnolipids from different

  20. First report of wild boar susceptibility to Porcine circovirus type 3: High prevalence in the Colli Euganei Regional Park (Italy) in the absence of clinical signs.

    Science.gov (United States)

    Franzo, Giovanni; Tucciarone, Claudia Maria; Drigo, Michele; Cecchinato, Mattia; Martini, Marco; Mondin, Alessandra; Menandro, Maria Luisa

    2018-05-18

    The genus Circovirus includes one of the most relevant infectious agents affecting domestic pigs, Porcine circovirus type 2 (PCV-2). The wild boar susceptibility to this pathogen has also been demonstrated although the actual epidemiological role of wild populations is still debated. In recent times, a new circovirus, Porcine circovirus type 3 (PCV-3), has been discovered and reported in the presence of several clinical conditions. However, no information is currently available about PCV-3 circulation and prevalence in wild boar. To fill this gap, 187 wild boar serum samples were collected in the Colli Euganei Regional Park (Northern Italy) and screened for PCV-3, demonstrating a high viral prevalence (approximately 30%). No gender differences were demonstrated while a lower infection prevalence was observed in animals younger than 12 months compared to older ones, differently from what described in commercial pigs. Almost all sampled animals were in good health conditions and no association was proven between PCV-3 status and clinical syndromes in wild animals. The genetic characterization of selected strains enlightened a relevant variability and the absence of closely related strains originating from domestic pigs. Therefore, the observed scenario is suggestive of multiple introductions from other wild or domestic swine populations followed by prolonged circulation and independent evolution. Worldwide, this study reports for the first time the high susceptibility of the wild boar to PCV-3 infection. The high prevalence and the absence of association with clinical signs support the marginal role of this virus in the wild boar population ecology. However, its epidemiological role as reservoir endangering commercial swine cannot be excluded and will require further investigations. © 2018 Blackwell Verlag GmbH.

  1. Complete genome sequence of Parvibaculum lavamentivorans type strain (DS-1(T)).

    Science.gov (United States)

    Schleheck, David; Weiss, Michael; Pitluck, Sam; Bruce, David; Land, Miriam L; Han, Shunsheng; Saunders, Elizabeth; Tapia, Roxanne; Detter, Chris; Brettin, Thomas; Han, James; Woyke, Tanja; Goodwin, Lynne; Pennacchio, Len; Nolan, Matt; Cook, Alasdair M; Kjelleberg, Staffan; Thomas, Torsten

    2011-12-31

    Parvibaculum lavamentivorans DS-1(T) is the type species of the novel genus Parvibaculum in the novel family Rhodobiaceae (formerly Phyllobacteriaceae) of the order Rhizobiales of Alphaproteobacteria. Strain DS-1(T) is a non-pigmented, aerobic, heterotrophic bacterium and represents the first tier member of environmentally important bacterial communities that catalyze the complete degradation of synthetic laundry surfactants. Here we describe the features of this organism, together with the complete genome sequence and annotation. The 3,914,745 bp long genome with its predicted 3,654 protein coding genes is the first completed genome sequence of the genus Parvibaculum, and the first genome sequence of a representative of the family Rhodobiaceae.

  2. Identification of tms-26 as an allele of the gcaD gene, which encodes N-acetylglucosamine 1-phosphate uridyltransferase in Bacillus subtilis

    DEFF Research Database (Denmark)

    Hove-Jensen, Bjarne

    1992-01-01

    -acetylglucosamine 1-phosphate, the substrate of the uridyltransferase activity, was elevated more than 40-fold in the mutant strain at the permissive temperature compared with the level in the wild-type strain. During a temperature shift, the level of UDP-N-acetylglucosamine, the product of the uridyltransferase...... activity, decreased much more in the mutant strain than in the wild-type strain. An Escherichia coli strain harboring the wild-type version of the tms-26 allele on a plasmid contained increased N-acetylglucosamine 1-phosphate uridyltransferase activity compared with that in the haploid strain...

  3. Mutagenesis at the ad-3A and ad-3B loci in haploid UV-sensitive strains of Neurospora crassa. Pt. 6

    International Nuclear Information System (INIS)

    De Serres, F.J.; Inoue, H.; Schuepbach, M.E.

    1983-01-01

    Genetic characterization of ad-3B mutants induced in wild-type and UV-sensitive strains has revealed qualitative differences between the spectra of genetic alterations at the molecular level. Ad-3B mutants induced in the two nucleotide excision-repair-deficient strains upr-1 and uvs-2 had significantly lower frequencies of nonpolarized complementation patterns and higher frequencies of noncomplementing mutants than ad-3B mutants induced in the wild-type strain in samples induced by either UV, #betta#-rays, 4NQO or MNNG. In these same samples ad-3B mutants induced in uvs-4, uvs-5 or uvs-6 did not differ significantly from those induced in the wild-type strain. After ICR-170 treatment, ad-3B mutants induced in the UV-sensitive strains did not differ significantly from those induced in wild-type. The comparisons in the present and previous studies demonstrate that the process of mutation-induction in the ad-3 region is under the control of other loci that not only alter mutant recovery quantitatively but also qualitatively. These data have important implications for comparative chemical mutagenesis, since the spectrum of genetic alterations produced by a given agent can be modified markedly as a result of defects in DNA repair. (orig./AJ)

  4. Occurrence and characterization of stx and/or eae-positive Escherichia coli isolated from wildlife, including a typical EPEC strain from a wild boar.

    Science.gov (United States)

    Alonso, Carla Andrea; Mora, Azucena; Díaz, Dafne; Blanco, Miguel; González-Barrio, David; Ruiz-Fons, Francisco; Simón, Carmen; Blanco, Jorge; Torres, Carmen

    2017-08-01

    Shiga toxin-producing E. coli (STEC) and enteropathogenic E. coli (EPEC) strains are food-borne pathogens associated with acute diarrhea. Haemolytic-uremic syndrome (HUS) is often a complication of STEC infection. In order to examine the occurrence, serotypes, virulence and antimicrobial-resistance profiles of STEC and EPEC in wildlife, 326 faecal E. coli strains from 304 clinically healthy animals were analyzed. For this approach stx 1 , stx 2 and eae genes, as well as accessory virulence determinants (ehx, hlyA, saa, tia, bfp, subAB) were PCR-screened and sequenced. Serotyping was performed employing all available O (O1-O185) and H (H1-H56) antisera. Genetic diversity was analyzed by XbaI-PFGE and phylotyping. Thirteen STEC (4.3%) and 10 EPEC (3.3%) were identified among 12 deer, 3 mouflon, 6 wild boars and 2 birds. Nine STEC showed seropathotypes B (O145:[H28]) and C (O22:H8, O128:[H2]) associated with HUS, and D (O110:H28, O146:H21, O146:[H28], ONT:H8) associated with human diarrhea. Although most isolates harbored stx 2b and stx 1c variants, stx 2a and stx 1a (related with severe disease) were also detected. Additionally, the eae gene was present in one stx 2a -positive O145:[H28] STEC from a deer and 11 STEC harbored subAB genes (mainly the subAB 2 variant). EPEC isolates showed 7 different intimin variants (β1, β2, γ1, ε1, ζ1, ι1-A, κ). Interestingly, the O49:[H10] eae-κ EPEC isolated from a wild boar was bfpA-positive showing a combination of serotype/virulence profile previously detected among human clinical tEPEC. Based on present results, wild ruminants, wild boars and to a lesser extent birds would be carriers of potentially pathogenic STEC and EPEC strains. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Reducing cytoplasmic polyamine oxidase activity in Arabidopsis increases salt and drought tolerance by reducing reactive oxygen species production and increasing defense gene expression

    Directory of Open Access Journals (Sweden)

    G.H.M. eSagor

    2016-02-01

    Full Text Available The link between polyamine oxidases (PAOs, which function in polyamine catabolism, and stress responses remains elusive. Here, we address this issue using Arabidopsis pao mutants in which the expression of the five PAO genes is knocked-out or knocked-down. As the five single pao mutants and wild type (WT showed similar response to salt stress, we tried to generate the mutants that have either the cytoplasmic PAO pathway (pao1 pao5 or the peroxisomal PAO pathway (pao2 pao3 pao4 silenced. However, the latter triple mutant was not obtained. Thus, in this study, we used two double mutants, pao1 pao5 and pao2 pao4. Of interest, pao1 pao5 mutant was NaCl- and drought-tolerant, whereas pao2 pao4 showed similar sensitivity to those stresses as WT. To reveal the underlying mechanism of salt tolerance, further analyses were performed. Na uptake of the mutant (pao1 pao5 decreased to 75% of WT. PAO activity of the mutant was reduced to 62% of WT. The content of reactive oxygen species (ROS such as hydrogen peroxide, a reaction product of PAO action, and superoxide anion in the mutant became 81% and 72% of the levels in WT upon salt treatment. The mutant contained 2.8-fold higher thermospermine compared to WT. Moreover, the mutant induced the genes of salt overly sensitive-, abscisic acid (ABA-dependent- and ABA-independent- pathways more strongly than WT upon salt treatment. The results suggest that the Arabidopsis plant silencing cytoplasmic PAOs shows salinity tolerance by reducing ROS production and strongly inducing subsets of stress-responsive genes under stress conditions.

  6. DNA binding properties of dioxin receptors in wild-type and mutant mouse hepatoma cells

    International Nuclear Information System (INIS)

    Cuthill, S.; Poellinger, L.

    1988-01-01

    The current model of action of 2,3,7,8-tetrachlorodibenzo-p-dioxin (dioxin) entails stimulation of target gene transcription via the formation of dioxin-receptor complexes and subsequent accumulation of the complexes within the cell nucleus. Here, the authors have analyzed the DNA binding properties of the dioxin receptor in wild-type mouse hepatoma (Hepa 1c1c7) cells and a class of nonresponsive mutant cells which fail to accumulate dioxin-receptor complexes within the nucleus in vivo. In vitro, both the wild-type and mutant [ 3 H]dioxin-receptor complexes exhibited low affinity for DNA-cellulose (5-8% and around 4% retention, respectively) in the absence of prior biochemical manipulations. However, following chromatography on heparin-Sepharose, the wild-type but not the mutant dioxin receptor was transformed to a species with an increased affinity for DNA (40-50% retention on DNA-cellulose). The gross molecular structure of the mutant, non DNA binding dioxin receptor did not appear to be altered as compared to that of the wild-type receptor. These results imply that the primary deficiency in the mutant dioxin receptor form may reside at the DNA binding level and that, in analogy to steroid hormone receptors, DNA binding of the receptor may be an essential step in the regulation of target gene transcription by dioxin

  7. Complete Genome Sequences of emm111 Type Streptococcus pyogenes Strain GUR, with Antitumor Activity, and Its Derivative Strain GURSA1 with an Inactivated emm Gene

    DEFF Research Database (Denmark)

    Suvorova, Maria A; Tsapieva, Anna N; Bak, Emilie Glad

    2017-01-01

    We present here the complete genome sequence of Streptococcus pyogenes type emm111 strain GUR, a throat isolate from a scarlet fever patient, which has been used to treat cancer patients in the former Soviet Union. We also present the complete genome sequence of its derivative strain GURSA1...

  8. Influence of developmental stage and genotype on liver mRNA levels among wild, domesticated, and hybrid rainbow trout (Oncorhynchus mykiss).

    Science.gov (United States)

    White, Samantha L; Sakhrani, Dionne; Danzmann, Roy G; Devlin, Robert H

    2013-10-02

    Release of domesticated strains of fish into nature may pose a threat to wild populations with respect to their evolved genetic structure and fitness. Understanding alterations that have occurred in both physiology and genetics as a consequence of domestication can assist in evaluating the risks posed by introgression of domesticated genomes into wild genetic backgrounds, however the molecular causes of these consequences are currently poorly defined. The present study has examined levels of mRNA in fast-growing pure domesticated (D), slow-growing age-matched pure wild (Wa), slow-growing size-matched pure wild (Ws), and first generation hybrid cross (W/D) rainbow trout (Oncorhynchus mykiss) to investigate the influence of genotype (domesticated vs. wild, and their interactions in hybrids) and developmental stage (age- or size-matched animals) on genetic responses (i.e. dominant vs. recessive) and specific physiological pathways. Highly significant differences in mRNA levels were found between domesticated and wild-type rainbow trout genotypes (321 mRNAs), with many mRNAs in the wild-domesticated hybrid progeny showing intermediate levels. Differences were also found between age-matched and size-matched wild-type trout groups (64 mRNAs), with unique mRNA differences for each of the wild-type groups when compared to domesticated trout (Wa: 114 mRNAs, Ws: 88 mRNAs), illustrating an influence of fish developmental stage affecting findings when used as comparator groups to other genotypes. Analysis of differentially expressed mRNAs (found for both wild-type trout to domesticated comparisons) among the genotypes indicates that 34.8% are regulated consistent with an additive genetic model, whereas 39.1% and 26.1% show a recessive or dominant mode of regulation, respectively. These molecular data are largely consistent with phenotypic data (growth and behavioural assessments) assessed in domesticated and wild trout strains. The present molecular data are concordant with

  9. Characterization of Clostridium difficile Strains in British Columbia, Canada: A Shift from NAP1 Majority (2008 to Novel Strain Types (2013 in One Region

    Directory of Open Access Journals (Sweden)

    Agatha N. Jassem

    2016-01-01

    Full Text Available Background. Clostridium difficile is a major cause of gastrointestinal illness. Epidemic NAP1 strains contain toxins A and B, a deletion in repressor tcdC, and a binary toxin. Objectives. To determine the molecular epidemiology of C. difficile in British Columbia and compare between two time points in one region. Methods. C. difficile isolates from hospital and community laboratories (2008 and one Island Health hospital laboratory (2013 were characterized by pulsed-field gel electrophoresis, PCR-ribotyping, toxin possession, tcdC genotype, and antimicrobial susceptibility. Results. In 2008, 42.7% of isolates had NAP1 designation. Hospital-collected isolates were associated with older patients and more NAP1 types. Unlike other isolates, most NAP1 isolates possessed binary toxin and a 19 bp loss in tcdC. All isolates were susceptible to metronidazole and vancomycin. A 2013 follow-up revealed a 28.9% decrease in NAP1 isolates and 20.0% increase in isolates without NAP designation in one region. Then, community-associated cases were seen in younger patients, while NAP types were evenly distributed. Isolates without NAP designation did not cluster with a PFGE pattern or ribotype. Conclusions. Evaluation of C. difficile infections within British Columbia revealed demographic associations, epidemiological shifts, and characteristics of strain types. Continuous surveillance of C. difficile will enable detection of emerging strains.

  10. Automatic Detection of Wild-type Mouse Cranial Sutures

    DEFF Research Database (Denmark)

    Ólafsdóttir, Hildur; Darvann, Tron Andre; Hermann, Nuno V.

    , automatic detection of the cranial sutures becomes important. We have previously built a craniofacial, wild-type mouse atlas from a set of 10 Micro CT scans using a B-spline-based nonrigid registration method by Rueckert et al. Subsequently, all volumes were registered nonrigidly to the atlas. Using......, the observer traced the sutures on each of the mouse volumes as well. The observer outperforms the automatic approach by approximately 0.1 mm. All mice have similar errors while the suture error plots reveal that suture 1 and 2 are cumbersome, both for the observer and the automatic approach. These sutures can...

  11. Mutagenesis at the ad-3A and ad-3B loci in haploid UV-sensitive strains of Neurospora crassa. Pt. 2

    International Nuclear Information System (INIS)

    Serres, F.J. de

    1980-01-01

    UV-induced inactivation and induction of mutations at the ad-3A and ad-3B loci of Neurospora crassa have been compared among 7 different UV-sensitive strains and a standard wild-type strain. The 7 strains show varying degrees of sensitivity to UV-induced inactivation, with the relative sensitivity being: uvs-2 > uvs-3 > uvs-4 > uvs-6 > upr-1 > uvs-5 > uvs-1. Studies on the induction of ad-3 mutants by UV show that the 2 excision-repair deficient mutants uvs-2 and upr-1 exhibit enhanced ad-3 mutant frequencies, while uvs-4 and uvs-5 exhibit reduced ad-3 mutant frequencies, and uvs-3 completely eliminates UV mutagenesis. The ad-3 mutation-induction curves obtained with uvs-1 or uvs-6 are not significantly different from that found with the wild-type strain. (orig.)

  12. Optimization of the cultivation conditions for mushroom production with European wild strains of Agaricus subrufescens and Brazilian cultivars.

    Science.gov (United States)

    Llarena-Hernández, Carlos R; Largeteau, Michèle L; Ferrer, Nathalie; Regnault-Roger, Catherine; Savoie, Jean-Michel

    2014-01-15

    The almond mushroom Agaricus subrufescens (formerly Agaricus blazei or Agaricus brasiliensis) is cultivated at commercial level in Brazil and some Asian countries on local substrates and casing mixtures. Despite its tropical origin, A. subrufescens might be a seasonal option for mushroom growers in western countries, where some wild strains have been isolated. For this purpose, cultivation conditions were developed starting from the substrate and casing mixture commonly used for commercial production of the button mushroom Agaricus bisporus in France. The commercial compost, based on wheat straw and horse manure, used for A. bisporus and the casing mixture (peat and limestone) supplemented with fine sand proved efficient to grow A. subrufescens. Increasing the depth of the casing layer improved significantly the yield and time to fruiting. Daily variations in temperature did not markedly modify the yield. Significantly higher mushroom biomass was obtained with three wild European strains compared with three Brazilian cultivars. The very productive wild strain CA438-A gave mushrooms of size and dry matter content comparable to those of a cultivar. Commercial production of A. subrufescens can be developed in western countries on the wheat straw-based substrate commonly used for A. bisporus in these regions, by a simple modification of the casing mixture and maintaining the incubation temperature throughout the crop, which is expected to save energy during summer. Good yields were obtained cultivating European strains under optimised parameters. © 2013 Society of Chemical Industry.

  13. Establishment and characterization of a hypocatalasemic mouse cell strain

    International Nuclear Information System (INIS)

    Utsumi, Hiroshi; Tano, Keizo; Hashimoto, Mitsumasa W.; Kodama, Seiji; Watanabe, Hiromitsu

    1998-01-01

    Contact-inhibited catalase-deficient fibroblast cell strain has been established from the homozygous hypocatalasemic C3H/Cs b mutant mouse. This cell strain has low level of catalase enzyme activity and has normal level of enzyme activities of both glutathione peroxidase and superoxide dismutase. Catalase-deficient C3H/Cs b mutant cell strain is markedly more sensitive to the toxicity of hydrogen peroxide compared to wild-type C3H/Cs a cell strain. In addition, mutant cell strain is sensitive to X-rays and near-UV compared to wild-type cell strain, but shows the same sensitivities to topoisomerase II inhibitors, adriamycin and 4'-(9-acridinylamino) methanesulfon-m-anisidide (m-AMSA), and the DNA cross-linking agents, cis-diamminedichloroplatinum (II) (cis-Pt) and trans-diamminedichloroplatinum (II) (trans-Pt). These cell strains will be of use in the study of the roles which catalase plays in the intracellular prevention of DNA damage induced by oxidative stress. (author)

  14. Synthesis, Docking, In Vitro and In Vivo Antimalarial Activity of Hybrid 4-aminoquinoline-1,3,5-triazine Derivatives Against Wild and Mutant Malaria Parasites.

    Science.gov (United States)

    Bhat, Hans Raj; Singh, Udaya Pratap; Gahtori, Prashant; Ghosh, Surajit Kumar; Gogoi, Kabita; Prakash, Anil; Singh, Ramendra K

    2015-09-01

    A new series of hybrid 4-aminoquinoline-1,3,5-triazine derivatives was synthesized by a four-step reaction. Target compounds were screened for in vitro antimalarial activity against chloroquine-sensitive (3D-7) and chloroquine-resistant (RKL-2) strains of Plasmodium falciparum. Compounds exhibited, by and large, good antimalarial activity against the resistant strain, while two of them, that is 8g and 8a, displayed higher activity against both the strains of P. falciparum. Additionally, docking study was performed on both wild (1J3I.pdb) and quadruple mutant (N51I, C59R, S108 N, I164L, 3QG2.pdb) type pf-DHFR-TS to highlight the structural features of hybrid molecules. © 2014 John Wiley & Sons A/S.

  15. Vaccine and Wild-Type Strains of Yellow Fever Virus Engage Distinct Entry Mechanisms and Differentially Stimulate Antiviral Immune Responses

    Directory of Open Access Journals (Sweden)

    Maria Dolores Fernandez-Garcia

    2016-02-01

    Full Text Available The live attenuated yellow fever virus (YFV vaccine 17D stands as a “gold standard” for a successful vaccine. 17D was developed empirically by passaging the wild-type Asibi strain in mouse and chicken embryo tissues. Despite its immense success, the molecular determinants for virulence attenuation and immunogenicity of the 17D vaccine are poorly understood. 17D evolved several mutations in its genome, most of which lie within the envelope (E protein. Given the major role played by the YFV E protein during virus entry, it has been hypothesized that the residues that diverge between the Asibi and 17D E proteins may be key determinants of attenuation. In this study, we define the process of YFV entry into target cells and investigate its implication in the activation of the antiviral cytokine response. We found that Asibi infects host cells exclusively via the classical clathrin-mediated endocytosis, while 17D exploits a clathrin-independent pathway for infectious entry. We demonstrate that the mutations in the 17D E protein acquired during the attenuation process are sufficient to explain the differential entry of Asibi versus 17D. Interestingly, we show that 17D binds to and infects host cells more efficiently than Asibi, which culminates in increased delivery of viral RNA into the cytosol and robust activation of the cytokine-mediated antiviral response. Overall, our study reveals that 17D vaccine and Asibi enter target cells through distinct mechanisms and highlights a link between 17D attenuation, virus entry, and immune activation.

  16. Attenuated stress response to acute restraint and forced swimming stress in arginine vasopressin 1b receptor subtype (Avpr1b) receptor knockout mice and wild-type mice treated with a novel Avpr1b receptor antagonist.

    Science.gov (United States)

    Roper, J A; Craighead, M; O'Carroll, A-M; Lolait, S J

    2010-11-01

    Arginine vasopressin (AVP) synthesised in the parvocellular region of the hypothalamic paraventricular nucleus and released into the pituitary portal vessels acts on the 1b receptor subtype (Avpr1b) present in anterior pituitary corticotrophs to modulate the release of adrenocorticotrophic hormone (ACTH). Corticotrophin-releasing hormone is considered the major drive behind ACTH release; however, its action is augmented synergistically by AVP. To determine the extent of vasopressinergic influence in the hypothalamic-pituitary-adrenal axis response to restraint and forced swimming stress, we compared the stress hormone levels [plasma ACTH in both stressors and corticosterone (CORT) in restraint stress only] following acute stress in mutant Avpr1b knockout (KO) mice compared to their wild-type controls following the administration of a novel Avpr1b antagonist. Restraint and forced swimming stress-induced increases in plasma ACTH were significantly diminished in mice lacking a functional Avpr1b and in wild-type mice that had been pre-treated with Avpr1b antagonist. A corresponding decrease in plasma CORT levels was also observed in acute restraint-stressed knockout male mice, and in Avpr1b-antagonist-treated male wild-type mice. By contrast, plasma CORT levels were not reduced in acutely restraint-stressed female knockout animals, or in female wild-type animals pre-treated with Avpr1b antagonist. These results demonstrate that pharmacological antagonism or inactivation of Avpr1b causes a reduction in the hypothalamic-pituitary-adrenal (HPA) axis response, particularly ACTH, to acute restraint and forced swimming stress, and show that Avpr1b knockout mice constitute a model by which to study the contribution of Avpr1b to the HPA axis response to acute stressors. © 2010 The Authors. Journal of Neuroendocrinology © 2010 Blackwell Publishing Ltd.

  17. Genetic pathway in acquisition and loss of vancomycin resistance in a methicillin resistant Staphylococcus aureus (MRSA strain of clonal type USA300.

    Directory of Open Access Journals (Sweden)

    Susana Gardete

    2012-02-01

    Full Text Available An isolate of the methicillin-resistant Staphylococcus aureus (MRSA clone USA300 with reduced susceptibility to vancomycin (SG-R (i.e, vancomycin-intermediate S. aureus, VISA and its susceptible "parental" strain (SG-S were recovered from a patient at the end and at the beginning of an unsuccessful vancomycin therapy. The VISA phenotype was unstable in vitro generating a susceptible revertant strain (SG-rev. The availability of these 3 isogenic strains allowed us to explore genetic correlates of antibiotic resistance as it emerged in vivo. Compared to the susceptible isolate, both the VISA and revertant strains carried the same point mutations in yycH, vraG, yvqF and lspA genes and a substantial deletion within an intergenic region. The revertant strain carried a single additional frameshift mutation in vraS which is part of two component regulatory system VraSR. VISA isolate SG-R showed complex alterations in phenotype: decreased susceptibility to other antibiotics, slow autolysis, abnormal cell division and increased thickness of cell wall. There was also altered expression of 239 genes including down-regulation of major virulence determinants. All phenotypic properties and gene expression profile returned to parental levels in the revertant strain. Introduction of wild type yvqF on a multicopy plasmid into the VISA strain caused loss of resistance along with loss of all the associated phenotypic changes. Introduction of the wild type vraSR into the revertant strain caused recovery of VISA type resistance. The yvqF/vraSR operon seems to function as an on/off switch: mutation in yvqF in strain SG-R turns on the vraSR system, which leads to increase in vancomycin resistance and down-regulation of virulence determinants. Mutation in vraS in the revertant strain turns off this regulatory system accompanied by loss of resistance and normal expression of virulence genes. Down-regulation of virulence genes may provide VISA strains with a "stealth

  18. Genotype and Phenotype of Echinococcus granulosus Derived from Wild Sheep (Ovis orientalis) in Iran.

    Science.gov (United States)

    Eslami, Ali; Meshgi, Behnam; Jalousian, Fatemeh; Rahmani, Shima; Salari, Mohammad Ali

    2016-02-01

    The aim of the present study is to determine the characteristics of genotype and phenotype of Echinococcus granulosus derived from wild sheep and to compare them with the strains of E. granulosus sensu stricto (sheep-dog) and E. granulosus camel strain (camel-dog) in Iran. In Khojir National Park, near Tehran, Iran, a fertile hydatid cyst was recently found in the liver of a dead wild sheep (Ovis orientalis). The number of protoscolices (n=6,000) proved enough for an experimental infection in a dog. The characteristics of large and small hooks of metacestode were statistically determined as the sensu stricto strain but not the camel strain (P=0.5). To determine E. granulosus genotype, 20 adult worms of this type were collected from the infected dog. The second internal transcribed spacer (ITS2) of the nuclear ribosomal DNA (rDNA) and cytochrome c oxidase 1 subunit (COX1) of the mitochondrial DNA were amplified from individual adult worm by PCR. Subsequently, the PCR product was sequenced by Sanger method. The lengths of ITS2 and COX1 sequences were 378 and 857 bp, respectively, for all the sequenced samples. The amplified DNA sequences from both ribosomal and mitochondrial genes were highly similar (99% and 98%, respectively) to that of the ovine strain in the GenBank database. The results of the present study indicate that the morpho-molecular features and characteristics of E. granulosus in the Iranian wild sheep are the same as those of the sheep-dog E. granulosus sensu stricto strain.

  19. A Real-Time PCR Assay to Identify and Discriminate Among Wild-Type and Vaccine Strains of Varicella-Zoster Virus and Herpes Simplex Virus in Clinical Specimens, and Comparison With the Clinical Diagnoses

    Science.gov (United States)

    Harbecke, Ruth; Oxman, Michael N.; Arnold, Beth A.; Ip, Charlotte; Johnson, Gary R.; Levin, Myron J.; Gelb, Lawrence D.; Schmader, Kenneth E.; Straus, Stephen E.; Wang, Hui; Wright, Peter F.; Pachucki, Constance T.; Gershon, Anne A.; Arbeit, Robert D.; Davis, Larry E.; Simberkoff, Michael S.; Weinberg, Adriana; Williams, Heather M.; Cheney, Carol; Petrukhin, Luba; Abraham, Katalin G.; Shaw, Alan; Manoff, Susan; Antonello, Joseph M.; Green, Tina; Wang, Yue; Tan, Charles; Keller, Paul M.

    2014-01-01

    A real-time PCR assay was developed to identify varicella-zoster virus (VZV) and herpes simplex virus (HSV) DNA in clinical specimens from subjects with suspected herpes zoster (HZ; shingles). Three sets of primers and probes were used in separate PCR reactions to detect and discriminate among wild-type VZV (VZV-WT), Oka vaccine strain VZV (VZV-Oka), and HSV DNA, and the reaction for each virus DNA was multiplexed with primers and probe specific for the human β-globin gene to assess specimen adequacy. Discrimination of all VZV-WT strains, including Japanese isolates and the Oka parent strain, from VZV-Oka was based upon a single nucleotide polymorphism at position 106262 in ORF 62, resulting in preferential amplification by the homologous primer pair. The assay was highly sensitive and specific for the target virus DNA, and no cross-reactions were detected with any other infectious agent. With the PCR assay as the gold standard, the sensitivity of virus culture was 53% for VZV and 77% for HSV. There was 92% agreement between the clinical diagnosis of HZ by the Clinical Evaluation Committee and the PCR assay results. PMID:19475609

  20. Activation Of Wild-Type Hras Suppresses The Earliest Stages Of Pancreatic Cancer

    Directory of Open Access Journals (Sweden)

    Jamie Weyandt

    2015-08-01

    Conclusions: Loss of wild-type Hras promotes the earliest stages of pancreatic tumorigenesis, and moreover results in more rapid progression of the disease. As such, mechanisms leading to activation of wild-type Ras proteins, including but not limited to redox-dependent reactions, may influence the development of pancreatic cancer.

  1. SPECT with [99mTc]-d,l-hexamethyl-propylene amine oxime (HM-PAO) compared with regional cerebral blood flow measured by PET

    DEFF Research Database (Denmark)

    Yonekura, Y; Nishizawa, S; Mukai, Thomas Søgaard

    1988-01-01

    In order to validate the use of technetium-99m-d,l-hexamethylpropyleneamine oxime (HM-PAO) as a flow tracer, a total of 21 cases were studied with single photon emission computerized tomography (SPECT), and compared to regional cerebral blood flow (rCBF) measured by position emission tomography...... (PET) using the oxygen-15 CO2 inhalation technique. Although HM-PAO SPECT and rCBF PET images showed a similar distribution pattern the HM-PAO SPECT image showed less contrast between high and low activity flow regions than the rCBF image and a nonlinear relationship between HM-PAO activity and r......CBF was shown. Based on the assumption of flow-dependent backdiffusion of HM-PAO from the brain, we applied a "linearization algorithm" to correct the HM-PAO SPECT images. The corrected HM-PAO SPECT images revealed a good linear correlation with rCBF (r = 0.901, p less than 0.001). The results indicated HM-PAO...

  2. Genetic relationships between clinical and non-clinical strains of Yersinia enterocolitica biovar 1A as revealed by multilocus enzyme electrophoresis and multilocus restriction typing

    Directory of Open Access Journals (Sweden)

    Virdi Jugsharan S

    2010-05-01

    Full Text Available Abstract Background Genetic relationships among 81 strains of Y. enterocolitica biovar 1A isolated from clinical and non-clinical sources were discerned by multilocus enzyme electrophoresis (MLEE and multilocus restriction typing (MLRT using six loci each. Such studies may reveal associations between the genotypes of the strains and their sources of isolation. Results All loci were polymorphic and generated 62 electrophoretic types (ETs and 12 restriction types (RTs. The mean genetic diversity (H of the strains by MLEE and MLRT was 0.566 and 0.441 respectively. MLEE (DI = 0.98 was more discriminatory and clustered Y. enterocolitica biovar 1A strains into four groups, while MLRT (DI = 0.77 identified two distinct groups. BURST (Based Upon Related Sequence Types analysis of the MLRT data suggested aquatic serotype O:6,30-6,31 isolates to be the ancestral strains from which, clinical O:6,30-6,31 strains might have originated by host adaptation and genetic change. Conclusion MLEE revealed greater genetic diversity among strains of Y. enterocolitica biovar 1A and clustered strains in four groups, while MLRT grouped the strains into two groups. BURST analysis of MLRT data nevertheless provided newer insights into the probable evolution of clinical strains from aquatic strains.

  3. Complete genome sequences of six measles virus strains

    NARCIS (Netherlands)

    Phan, M.V.T. (My V.T.); C.M.E. Schapendonk (Claudia); B.B. Oude Munnink (Bas B.); M.P.G. Koopmans D.V.M. (Marion); R.L. de Swart (Rik); Cotten, M. (Matthew)

    2018-01-01

    textabstractGenetic characterization of wild-type measles virus (MV) strains is a critical component of measles surveillance and molecular epidemiology. We have obtained complete genome sequences of six MV strains belonging to different genotypes, using random-primed next generation sequencing.

  4. The retention of [99mTc]-d,l-HM-PAO in the human brain after intracarotid bolus injection

    DEFF Research Database (Denmark)

    Lassen, N A; Andersen, A R; Friberg, L

    1988-01-01

    [99mTc]-d,l-HM-PAO (HM-PAO) was injected rapidly into the internal carotid artery and its retention in the brain was recorded by external scintillation cameras in eight human subjects. A model is described based on three compartments: the lipophilic tracer in the blood pool of the brain, the lipo......[99mTc]-d,l-HM-PAO (HM-PAO) was injected rapidly into the internal carotid artery and its retention in the brain was recorded by external scintillation cameras in eight human subjects. A model is described based on three compartments: the lipophilic tracer in the blood pool of the brain...

  5. Thio and hydrogen peroxide modofication of recA induction in UV-irradiated wild-type and catalase-deficient Escherichia coli K12

    International Nuclear Information System (INIS)

    Claycamp, H.G.; Kam-Kuen Ho; DeRose, C.; Iowa Univ., Iowa City, IA

    1990-01-01

    Induction of recA in Escherichia coli, monitored as β-D-galactosidase activity in recA-lacZ fusion strains, was shown to be elevated and prolonged by dithiothreitol (DTT) treatment after far-UV radiation. Pretreatment of UV-irradiated coltures using DTT led to a shortened recA response and little increase of β-Gal yield. Similar studies were performed using a catalase-deficient recA-lacZ strain in which the major feature was elevated levels of recA-lacZ induction. Catalase activity in UV-irradiated wild-type cells was reduced by DTT treatment to levels as low as in a katE mutant strain, leading to similar recA-lacZ induction patterns between the strains. Neither DTT nor H 2 O 2 treatment of cells could induce significant recA transcription in the absence of UV-radiation, implying that both agents modify recA activity primarily by interfering with repair of recA-inducing DNA lesions. The results confirm previous studies suggesting that modification of DNA repair is probably a significant portion of thiol radiation protection. (author). 36 refs.; 7 figs.; 1 tab

  6. Evaluation of 99mTc-HM-PAO thigh accumulation in patients with cerebro-vascular disease

    International Nuclear Information System (INIS)

    Nishigaki, Hiroshi; Adachi, Itaru; Komori, Tsuyoshi; Tatsu, Yoshimitsu; Hisada, Youichi; Sueyoshi, Kouzou; Narabayashi, Isamu

    1993-01-01

    Technetium-99m d,l-hexamethyl-propyleneamine oxime ( 99m Tc-HM-PAO) cerebral SPECT and whole body scintigraphy (WBS) were performed in 5 patients without cerebro-vascular disease (CVD) (Group 1), 31 patients with CVD but not hemiparesis (Group 2) and 18 patients with CVD and hemiparesis (Group 3). Four ROIs were drawn manually around the whole body (WB), brain (Br), right and left thigh (Th). We calculated some ratios: the total counts in the brain over the total counts in the whole body (Br/WB), the total counts in the thigh over the total counts in the whole body (Th/WB) and the mean counts in the thigh over the mean counts in the brain (Th/Br). The Br/WB was 6.9±1.8%, rt-Th/WB was 4.9±2.1%, lt-Th/WB was 5.1±1.3% and Th/Br was 0.46±0.17 in group 1. Whole body scintigraphies in group 1 revealed clear and similar images between right and left thigh. The Br/WB was 6.7±1.4%, Th/WB of paretic side was 4.6±1.0%, Th/WB of non-paretic side was 5.8±1.2% and Th/Br was 0.47±0.18 in group 3. The Th/WB in non paretic side was significantly higher than that in paretic side (p 99m Tc-HM-PAO. It was possible that we evaluated not only cerebral perfusion but also muscle atrophy and/or perfusion in patients with CVD using 99m Tc-HM-PAO. (author)

  7. Yersinia spp. in Wild Rodents and Shrews in Finland.

    Science.gov (United States)

    Joutsen, Suvi; Laukkanen-Ninios, Riikka; Henttonen, Heikki; Niemimaa, Jukka; Voutilainen, Liina; Kallio, Eva R; Helle, Heikki; Korkeala, Hannu; Fredriksson-Ahomaa, Maria

    2017-05-01

    Yersinia enterocolitica and Yersinia pseudotuberculosis are important zoonotic bacteria causing human enteric yersiniosis commonly reported in Europe. All Y. pseudotuberculosis strains are considered pathogenic, while Y. enterocolitica include both pathogenic and nonpathogenic strains which can be divided into six biotypes (1A, 1B, and 2-5) and about 30 serotypes. The most common types causing yersiniosis in Europe are Y. enterocolitica bioserotypes 4/O:3 and 2/O:9. Strains belonging to biotype 1A are considered as nonpathogenic because they are missing important virulence genes like the attachment-invasion-locus (ail) gene in the chromosome and the virulence plasmid. The role of wild small mammals as a reservoir of enteropathogenic Yersinia spp. is still obscure. In this study, the presence of Yersinia spp. was examined from 1840 wild small mammals, including voles, mice, and shrews, trapped in Finland during a 7-year period. We isolated seven Yersinia species. Y. enterocolitica was the most common species, isolated from 8% of the animals; while most of these isolates represented nonpathogenic biotype 1A, human pathogenic bioserotype 2/O:9 was also isolated from a field vole. Y. pseudotuberculosis of bioserotype 1/O:2 was isolated from two shrews. The ail gene, which is typically only found in the isolates of biotypes 1B and 2-5 associated with yersiniosis, was frequently (23%) detected in the nonpathogenic isolates of biotype 1A and sporadically (6%) in Yersinia kristensenii isolates. Our results suggest that wild small mammals, especially voles, may serve as carriers for ail-positive Y. enterocolitica 1A and Y. kristensenii. We also demonstrate that voles and shrews sporadically excrete pYV-positive Y. enterocolitica 2/O:9 and Y. pseudotuberculosis 1/O:2, respectively, in their feces and, thus, can serve as a contamination source for vegetables by contaminating the soil.

  8. Polymorphism in hybrid male sterility in wild-derived Mus musculus musculus strains on proximal chromosome 17.

    Science.gov (United States)

    Vyskocilová, Martina; Prazanová, Gabriela; Piálek, Jaroslav

    2009-02-01

    The hybrid sterility-1 (Hst1) locus at Chr 17 causes male sterility in crosses between the house mouse subspecies Mus musculus domesticus (Mmd) and M. m. musculus (Mmm). This locus has been defined by its polymorphic variants in two laboratory strains (Mmd genome) when mated to PWD/Ph mice (Mmm genome): C57BL/10 (carrying the sterile allele) and C3H (fertile allele). The occurrence of sterile and/or fertile (wild Mmm x C57BL)F1 males is evidence that polymorphism for this trait also exists in natural populations of Mmm; however, the nature of this polymorphism remains unclear. Therefore, we derived two wild-origin Mmm strains, STUS and STUF, that produce sterile and fertile males, respectively, in crosses with C57BL mice. To determine the genetic basis underlying male fertility, the (STUS x STUF)F1 females were mated to C57BL/10 J males. About one-third of resulting hybrid males (33.8%) had a significantly smaller epididymis and testes than parental animals and lacked spermatozoa due to meiotic arrest. A further one-fifth of males (20.3%) also had anomalous reproductive traits but produced some spermatozoa. The remaining fertile males (45.9%) displayed no deviation from values found in parental individuals. QTL analysis of the progeny revealed strong associations of male fitness components with the proximal end of Chr 17, and a significant effect of the central section of Chr X on testes mass. The data suggest that genetic incompatibilities associated with male sterility have evolved independently at the proximal end of Chr 17 and are polymorphic within both Mmd and Mmm genomes.

  9. Contribution of Cell Elongation to the Biofilm Formation of Pseudomonas aeruginosa during Anaerobic Respiration

    Science.gov (United States)

    Park, Yongjin; Yoon, Sang Sun

    2011-01-01

    Pseudomonas aeruginosa, a gram-negative bacterium of clinical importance, forms more robust biofilm during anaerobic respiration, a mode of growth presumed to occur in abnormally thickened mucus layer lining the cystic fibrosis (CF) patient airway. However, molecular basis behind this anaerobiosis-triggered robust biofilm formation is not clearly defined yet. Here, we identified a morphological change naturally accompanied by anaerobic respiration in P. aeruginosa and investigated its effect on the biofilm formation in vitro. A standard laboratory strain, PAO1 was highly elongated during anaerobic respiration compared with bacteria grown aerobically. Microscopic analysis demonstrated that cell elongation likely occurred as a consequence of defective cell division. Cell elongation was dependent on the presence of nitrite reductase (NIR) that reduces nitrite (NO2 −) to nitric oxide (NO) and was repressed in PAO1 in the presence of carboxy-PTIO, a NO antagonist, demonstrating that cell elongation involves a process to respond to NO, a spontaneous byproduct of the anaerobic respiration. Importantly, the non-elongated NIR-deficient mutant failed to form biofilm, while a mutant of nitrate reductase (NAR) and wild type PAO1, both of which were highly elongated, formed robust biofilm. Taken together, our data reveal a role of previously undescribed cell biological event in P. aeruginosa biofilm formation and suggest NIR as a key player involved in such process. PMID:21267455

  10. Trehalose, glycogen and ethanol metabolism in the gcr1 mutant of Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Seker, Tamay; Hamamci, H.

    2003-01-01

    Since Gcr1p is pivotal in controlling the transcription of glycolytic enzymes and trehalose metabolism seems to be one of the control points of glycolysis, we examined trehalose and glycogen synthesis in response to 2 % glucose pulse during batch growth in gcr1 (glucose regulation-1) mutant lacking...... fully functional glycolytic pathway and in the wild-type strain. An increase in both trehalose and glycogen stores was observed 1 and 2 h after the pulse followed by a steady decrease in both the wild-type and the gcr1 mutant. The accumulation was faster while the following degradation was slower in gcr......1 cells compared to wild-type ones. Although there was no distinct glucose consumption in the mutant cells it seemed that the glucose repression mechanism is similar in gcr1 mutant and in wild-type strain at least with respect to trehalose and glycogen metabolism....

  11. Anatomical location differences between mutated and wild-type isocitrate dehydrogenase 1 in low-grade gliomas.

    Science.gov (United States)

    Yu, Jinhua; Shi, Zhifeng; Ji, Chunhong; Lian, Yuxi; Wang, Yuanyuan; Chen, Liang; Mao, Ying

    2017-10-01

    Anatomical location of gliomas has been considered as a factor implicating the contributions of a specific precursor cells during the tumor growth. Isocitrate dehydrogenase 1 (IDH1) is a pathognomonic biomarker with a significant impact on the development of gliomas and remarkable prognostic effect. The correlation between anatomical location of tumor and IDH1 states for low-grade gliomas was analyzed quantitatively in this study. Ninety-two patients diagnosed of low-grade glioma pathologically were recruited in this study, including 65 patients with IDH1-mutated glioma and 27 patients with wide-type IDH1. A convolutional neural network was designed to segment the tumor from three-dimensional magnetic resonance imaging images. Voxel-based lesion symptom mapping was then employed to study the tumor location distribution differences between gliomas with mutated and wild-type IDH1. In order to characterize the location differences quantitatively, the Automated Anatomical Labeling Atlas was used to partition the standard brain atlas into 116 anatomical volumes of interests (AVOIs). The percentages of tumors with different IDH1 states in 116 AVOIs were calculated and compared. Support vector machine and AdaBoost algorithms were used to estimate the IDH1 status based on the 116 location features of each patient. Experimental results proved that the quantitative tumor location measurement could be a very important group of imaging features in biomarker estimation based on radiomics analysis of glioma.

  12. Caffeine enhancement of radiation killing in different strains of Saccharomyces cerevisiae

    International Nuclear Information System (INIS)

    Hannan, M.A.; Nasim, A.

    1977-01-01

    Haploid and diploid wild type strains, and three classes of radiation-sensitive mutants of Saccharomyces cerrevisiae were tesed for enhancement of UV-inactivation by caffeine in growth medium. In addition the sensitizing effect of caffeine was studied in a haploid and a diploid wild type strain after gamma-irradiation. The drug sensitized the UV-irradiated cells of all strains except those reported to be only slightly UV-sensitive but highly sensitive to ionizing radiation. After gamma-irradiation, no coffeine-enhancement of killing was observed in stationary phase cells of either the haploid or the diploid strain. However, log-phase cells of both strains were partially sensitized. The results of both sets of experiments suggested that caffeine interferes with a recombinational repair occurring in cells in S or G2 phase. (orig.) [de

  13. Survival of Lactobacillus rhamnosus probiotic strains in peach jam during storage at different temperatures

    Directory of Open Access Journals (Sweden)

    Cinzia Lucia Randazzo

    2013-12-01

    Full Text Available The survival of six probiotic wild strains of Lactobacillus rhamnosus was compared with that of a type strain during 78 days of storage at 25 and 5 ºC in peach synthetic medium (PSM and commercial peach jam (PJ. Changes in viable cell counts, pH values, sugar content, and colour parameters were monitored. All strains exhibited better performances in PJ than in PSM, showing count values higher than 7 Log cfu g-1 up to 78 days of storage at 5 ºC. Almost all wild strains remained above the critical value of 6 Log cfu g-1 in samples stored at 25 ºC up to 45 days, while the Lb. rhamnosus GG type strain, used as control, was not able to survive later than 15 days. In the synthetic medium used, the strains showed better survival in the samples incubated at 25 ºC, remaining viable above the critical level up to 45 days of storage, except for the strain H12. The probiotic cultures added to jam did not significantly change the colour parameters of the product; however the metabolism of lactobacilli did cause changes in the pH and in the composition of sugars.

  14. Structural Characterization of Lignin in Wild-Type versus COMT Down-Regulated Switchgrass

    Energy Technology Data Exchange (ETDEWEB)

    Samuel, Reichel [School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA (United States); BioEnergy Science Center, Oak Ridge, TN (United States); Pu, Yunqiao, E-mail: yunqiao.pu@ipst.gatech.edu [BioEnergy Science Center, Oak Ridge, TN (United States); Institute of Paper Science and Technology, Georgia Institute of Technology, Atlanta, GA (United States); Jiang, Nan [School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA (United States); BioEnergy Science Center, Oak Ridge, TN (United States); Fu, Chunxiang [Forage Improvement Division, The Samuel Roberts Noble Foundation, Ardmore, OK (United States); Wang, Zeng-Yu [BioEnergy Science Center, Oak Ridge, TN (United States); Forage Improvement Division, The Samuel Roberts Noble Foundation, Ardmore, OK (United States); Ragauskas, Arthur, E-mail: yunqiao.pu@ipst.gatech.edu [School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA (United States); BioEnergy Science Center, Oak Ridge, TN (United States)

    2014-01-20

    This study examined the chemical structural characteristics of cellulolytic enzyme lignin isolated from switchgrass focusing on comparisons between wild-type control and caffeic acid 3-O-methyltransferase (COMT) down-regulated transgenic line. Nuclear magnetic resonance techniques including {sup 13}C, {sup 31}P, and two-dimensional {sup 13}C-{sup 1}H heteronuclear single quantum coherence as well as gel permeation chromatography were employed. Compared to the wild-type, the COMT down-regulated transgenic switchgrass lignin demonstrated a decrease in syringyl (S):guaiacyl (G) ratio and p-coumarate:ferulate ratio, an increase in relative abundance of phenylcoumaran unit, and a comparable content of total free phenolic OH groups along with formation of benzodioxane unit. In addition, COMT down-regulation had no significant effects on the lignin molecular weights during its biosynthesis process.

  15. Estimation of the Binding Free Energy of AC1NX476 to HIV-1 Protease Wild Type and Mutations Using Free Energy Perturbation Method.

    Science.gov (United States)

    Ngo, Son Tung; Mai, Binh Khanh; Hiep, Dinh Minh; Li, Mai Suan

    2015-10-01

    The binding mechanism of AC1NX476 to HIV-1 protease wild type and mutations was studied by the docking and molecular dynamics simulations. The binding free energy was calculated using the double-annihilation binding free energy method. It is shown that the binding affinity of AC1NX476 to wild type is higher than not only ritonavir but also darunavir, making AC1NX476 become attractive candidate for HIV treatment. Our theoretical results are in excellent agreement with the experimental data as the correlation coefficient between calculated and experimentally measured binding free energies R = 0.993. Residues Asp25-A, Asp29-A, Asp30-A, Ile47-A, Gly48-A, and Val50-A from chain A, and Asp25-B from chain B play a crucial role in the ligand binding. The mutations were found to reduce the receptor-ligand interaction by widening the binding cavity, and the binding propensity is mainly driven by the van der Waals interaction. Our finding may be useful for designing potential drugs to combat with HIV. © 2015 John Wiley & Sons A/S.

  16. A Novel 1,4-Dihydropyridine Derivative Improves Spatial Learning and Memory and Modifies Brain Protein Expression in Wild Type and Transgenic APPSweDI Mice.

    Directory of Open Access Journals (Sweden)

    Baiba Jansone

    Full Text Available Ca2+ blockers, particularly those capable of crossing the blood-brain barrier (BBB, have been suggested as a possible treatment or disease modifying agents for neurodegenerative disorders, e.g., Alzheimer's disease. The present study investigated the effects of a novel 4-(N-dodecyl pyridinium group-containing 1,4-dihydropyridine derivative (AP-12 on cognition and synaptic protein expression in the brain. Treatment of AP-12 was investigated in wild type C57BL/6J mice and transgenic Alzheimer's disease model mice (Tg APPSweDI using behavioral tests and immunohistochemistry, as well as mass spectrometry to assess the blood-brain barrier (BBB penetration. The data demonstrated the ability of AP-12 to cross the BBB, improve spatial learning and memory in both mice strains, induce anxiolytic action in transgenic mice, and increase expression of hippocampal and cortical proteins (GAD67, Homer-1 related to synaptic plasticity. The compound AP-12 can be seen as a prototype molecule for use in the design of novel drugs useful to halt progression of clinical symptoms (more specifically, anxiety and decline in memory of neurodegenerative diseases, particularly Alzheimer's disease.

  17. Effect of varying temperature on growth, morphology and soluble protein content of div I and div II mutant strains of bacillus sub tills

    International Nuclear Information System (INIS)

    Ahmed, A.; Sabri, A.N.

    2004-01-01

    In B.subtilis, cell division is controlled by div-genes which have been mapped on its circular chromosome. In the present work, div-mutant strains 1A316(div II), 1A317 and 1A318 (div I) were studied. These strains exhibited temperature sensitive cell division mutations. Colony morphology, cell morphology, staining behavior, growth rate and protein content of PY79 (wild type) and div-mutant strains (1A316, 1A317, 1A318) was studied at different temperatures ( 25 deg. Centi grade and 42 deg. with varying incubation periods(4, 16, 24, 48, 72,96 hrs). div-mutants differ from wild type (PY79) in colony morphology. Colony margin in PY79 was entire while in the div strains it is undulate. Staining behavior of cells as well as cell morphology i.e., cell size, cell types, formation of filaments/minicells were affected by high temperature. At higher temperature (42 deg. Centi grade), div-mutants undergo more severe lysis and degeneration as compare to wild type (PY79). Defective spores were produced by div-mutants at 25 deg. Centi grade and 42 deg. Centi grade. Tetrazolium overlay test was performed at 37 deg. Centi grade and 42 deg. Centi grade to check the spore germination ability of wild type and div-mutants. In 1A318, defective spores were produced at 37 deg. Centi grade, div-mutant was checked after 24 and 96 hrs at different temperatures (25, 37 and 42 deg. Centi grade). At all temperatures protein content were more in PY79 as compare to div-mutants. Also at 25 and 42 deg. Centi grade, protein content was more as compare to 37 deg. Centi grade. Protein contents was reduced at sporulation stages. Thus cell division mutations affect cell morphology, sporulation and germination processes in B.subtilis and thus are multifaceted mutations. (author)

  18. Analysis of physiological (pao/sub 2/, pulse and blood pressure) changes during modified ect under general anaesthesia

    International Nuclear Information System (INIS)

    Shah, M.; Shah, H.A.; Shah, F.S.

    2015-01-01

    To study the changes in physiological parameters i e PAO2, pulse and blood pressure changes during ECT under GA. Study Design: Quasi-experimental study. Place and Duration of Study: Department of Psychiatry and Department of Anaesthesiology, Combined Military Hospital Abbottabad from Sep 2009 to Feb 2010. Patients and Methods: A total of 50 patients with depression were given four separate ECT sessions each. All patients were anaesthetized using propofol 180-200 mg I/V and suxamethonium 50 mg i e 0.75-1 mg per kg I/V without atropine. They were stratified according to physiological changes including PAO2, pulse and blood pressure at 1, 2 and 5 min after ECT. Oxygen saturation was measured using a pulse oximeter, which measures saturations in the range of 65-100%. Results: Age range was 19-65 years; mean 46 years (SD+-13). Mean diastolic BP before ECT was 84.72 that decreased post ECT ie 78.02 and 77.46 and 74.44 at interval of 1, 2 and 5 minute respectively. Post-ECT pulse and PAO2 behaved similarly. Post ECT systolic BP decreased at 1 and 5 minutes. Pulse rate decreased after ECT. Conclusion: ECT under propofol is one of the most effective and safe modality of treatment for psychiatric patients under the supervision of qualified psychiatrists and anaesthesiologists and it gives more stable hemodynamic changes. (author)

  19. Quorum-sensing-regulated virulence factors in Pseudomonas aeruginosa are toxic to Lucilia sericata maggots

    DEFF Research Database (Denmark)

    Andersen, A S; Joergensen, B; Bjarnsholt, T

    2010-01-01

    Maggot debridement therapy (MDT) is widely used for debridement of chronic infected wounds; however, for wounds harbouring specific bacteria limited effect or failure of the treatment has been described. Here we studied the survival of Lucilia sericata maggots encountering Pseudomonas aeruginosa...... PAO1 in a simple assay with emphasis on the quorum-sensing (QS)-regulated virulence. The maggots were challenged with GFP-tagged P. aeruginosa wild-type (WT) PAO1 and a GFP-tagged P. aeruginosa DeltalasR rhlR (DeltaRR) QS-deficient mutant in different concentrations. Maggots were killed...

  20. Early Transcriptional Responses of Bovine Chorioallantoic Membrane Explants to Wild Type, ΔvirB2 or ΔbtpB Brucella abortus Infection

    Science.gov (United States)

    Mol, Juliana P. S.; Costa, Erica A.; Carvalho, Alex F.; Sun, Yao-Hui; Tsolis, Reneé M.; Paixão, Tatiane A.; Santos, Renato L.

    2014-01-01

    The pathogenesis of the Brucella-induced inflammatory response in the bovine placenta is not completely understood. In this study we evaluated the role of the B. abortus Type IV secretion system and the anti-inflammatory factor BtpB in early interactions with bovine placental tissues. Transcription profiles of chorioallantoic membrane (CAM) explants inoculated with wild type (strain 2308), ΔvirB2 or ΔbtpB Brucella abortus were compared by microarray analysis at 4 hours post infection. Transcripts with significant variation (>2 fold change; Pabortus resulted in slightly more genes with decreased than increased transcription levels. Conversely, infection of trophoblastic cells with the ΔvirB2 or the ΔbtpB mutant strains, that lack a functional T4SS or that has impaired inhibition of TLR signaling, respectively, induced more upregulated than downregulated genes. Wild type Brucella abortus impaired transcription of host genes related to immune response when compared to ΔvirB and ΔbtpB mutants. Our findings suggest that proinflammatory genes are negatively modulated in bovine trophoblastic cells at early stages of infection. The virB operon and btpB are directly or indirectly related to modulation of these host genes. These results shed light on the early interactions between B. abortus and placental tissue that ultimately culminate in inflammatory pathology and abortion. PMID:25259715

  1. Screening of wild type Streptomyces isolates able to overproduce clavulanic acid

    Directory of Open Access Journals (Sweden)

    Daniela A. Viana Marques

    2014-09-01

    Full Text Available The selection of new microorganisms able to produce antimicrobial compounds is hoped for to reduce their production costs and the side effects caused by synthetic drugs. Clavulanic acid is a β-lactam antibiotic produced by submerged culture, which is widely used in medicine as a powerful inhibitor of β-lactamases, enzymes produced by bacteria resistant to antibiotics such penicillin and cephalosporin. The purpose of this work was to select the best clavulanic acid producer among strains of Streptomyces belonging to the Microorganism Collection of the Department of Antibiotics of the Federal University of Pernambuco (DAUFPE. Initially, the strains were studied for their capacity to inhibit the action of β-lactamases produced by Klebsiella aerogenes ATCC 15380. From these results, five strains were selected to investigate the batch kinetics of growth and clavulanic acid production in submerged culture carried out in flasks. The results were compared with the ones obtained by Streptomyces clavuligerus ATCC 27064 selected as a control strain. The best clavulanic acid producer was Streptomyces DAUFPE 3060, molecularly identified as Streptomyces variabilis, which increased the clavulanic acid production by 28% compared to the control strain. This work contributes to the enlargement of knowledge on new Streptomyces wild strains able to produce clavulanic acid by submerged culture.

  2. Effect of Attachment Type on Denture Strain in Maxillary Implant Overdentures: Part 1. Overdenture with Palate.

    Science.gov (United States)

    Takahashi, Toshihito; Gonda, Tomoya; Maeda, Yoshinobu

    This study examined the effects of attachments on strain in maxillary implant overdentures supported by two or four implants. A maxillary edentulous model with implants inserted into anterior, premolar, and molar areas was fabricated, and three types of unsplinted attachments-ball, locator, and magnet-were set on the implants distributed under various conditions. Maxillary experimental dentures were fabricated, and two strain gauges were attached at the anterior midline on the labial and palatal sides. A vertical occlusal load of 98 N was applied and shear strain of the dentures was measured. On both sides, magnet attachments resulted in the lowest shear strain, while ball attachments resulted in the highest shear strain under most conditions. However, differences in shear strain among the three attachment types were not significant when supported by four implants, especially molar implants. Shear strain of the maxillary implant overdenture was lowest when using magnet attachments. Magnet attachments mounted on four implants are recommended to prevent denture complications when using maxillary implant overdentures.

  3. Isolation and properties of strains of Micrococcus (Deinococcus) radiodurans unable to excise ultraviolet light-induced pyrimidine dimers from DNA: evidence for two excision pathways

    International Nuclear Information System (INIS)

    Moseley, B.E.B.; Evans, D.M.

    1983-01-01

    A mutant of Deinococcus (formerly Micrococcus) radiodurans sensitive to both the lethal effect of mitomycin C and the mutagenic effect of simple alkylating agents, but having wild-type resistance to UV light, was treated with the mutagen N-methyl-N'-nitro-N-nitrosoguanidine. Three strains were isolated that were UV-sensitive, but had wild-type resistance to the lethal effect of methyl methanesulphonate and all were shown to be unable to excise pyrimidine dimers. The three strains UVS9, UVS25 and UVS78 had, in addition to the mutation in mtcA, mutations in loci designated uvsC, uvsD and uvsE, respectively. When the mutant mtcA gene was replaced by its wild-type allele in all three strains they became UV- and mitomycin C-resistant. On incubating the double mutants UVS9, UVS25 and UVS78 with wild-type DNA about 50% of the transformants selected for UV resistance were mitomycin C-sensitive and about 50% resistant depending on whether the mutant mtcA or the uvsC, D or E genes had been replaced by their wild-type alleles. Although strains mutant singly in uvsC, D or E were UV-resistant the rates of excision of pyrimidine dimers differed between them and was slower in all of them than in the wild-type and strain 302. (author)

  4. Identification of carbohydrate-binding domains in the attachment proteins of type 1 and type 3 reoviruses.

    Science.gov (United States)

    Chappell, J D; Duong, J L; Wright, B W; Dermody, T S

    2000-09-01

    The reovirus attachment protein, sigma1, is responsible for strain-specific patterns of viral tropism in the murine central nervous system and receptor binding on cultured cells. The sigma1 protein consists of a fibrous tail domain proximal to the virion surface and a virion-distal globular head domain. To better understand mechanisms of reovirus attachment to cells, we conducted studies to identify the region of sigma1 that binds cell surface carbohydrate. Chimeric and truncated sigma1 proteins derived from prototype reovirus strains type 1 Lang (T1L) and type 3 Dearing (T3D) were expressed in insect cells by using a baculovirus vector. Assessment of expressed protein susceptibility to proteolytic cleavage, binding to anti-sigma1 antibodies, and oligomerization indicates that the chimeric and truncated sigma1 proteins are properly folded. To assess carbohydrate binding, recombinant sigma1 proteins were tested for the capacity to agglutinate mammalian erythrocytes and to bind sialic acid presented on glycophorin, the cell surface molecule bound by type 3 reovirus on human erythrocytes. Using a panel of two wild-type and ten chimeric and truncated sigma1 proteins, the sialic acid-binding domain of type 3 sigma1 was mapped to a region of sequence proposed to form the more amino terminal of two predicted beta-sheet structures in the tail. This unit corresponds to morphologic region T(iii) observed in computer-processed electron micrographs of sigma1 protein purified from virions. In contrast, the homologous region of T1L sigma1 sequence was not implicated in carbohydrate binding; rather, sequences in the distal portion of the tail known as the neck were required. Results of these studies demonstrate that a functional receptor-binding domain, which uses sialic acid as its ligand, is contained within morphologic region T(iii) of the type 3 sigma1 tail. Furthermore, our findings indicate that T1L and T3D sigma1 proteins contain different arrangements of receptor

  5. Antibodies with higher bactericidal activity induced by a Neisseria gonorrhoeae Rmp deletion mutant strain.

    Directory of Open Access Journals (Sweden)

    Guocai Li

    Full Text Available Neisseria gonorrhoeae (N. gonorrhoeae outer membrane protein reduction modifiable protein (Rmp has strong immunogenicity. However, anti-Rmp antibodies block rather than preserve the antibacterial effects of protective antibodies, which hampers the development of vaccines for gonococcal infections. We herein constructed an Rmp deletion mutant strain of N. gonorrhoeae by gene homologous recombination. The 261-460 nucleotide residues of Rmp gene amplified from N. gonorrhoeae WHO-A strain were replaced with a kanamycin-resistant Kan gene amplified from pET-28a. The resultant hybridized DNA was transformed into N. gonorrhoeae WHO-A strain. PCR was used to screen the colonies in which wild-type Rmp gene was replaced with a mutant gene fragment. Western blotting revealed that the Rmp deletion mutant strain did not express Rmp protein. Rmp deletion did not alter the morphological and Gram staining properties of the mutant strain that grew slightly more slowly than the wild-type one. Rmp gene mutated stably throughout 25 generations of passage. Antibody-mediated complement-dependent cytotoxicity assay indicated that the antibodies induced by the mutant strain had evidently higher bactericidal activities than those induced by the wild-type strain. Further modification of the Rmp deletion mutant strain is still required in the development of novel live attenuated vaccines for gonorrhea by Opa genes deletion or screening of phenotypic variant strains that do not express Opa proteins.

  6. The new strains Brucella inopinata BO1 and Brucella species 83-210 behave biologically like classic infectious Brucella species and cause death in murine models of infection.

    Science.gov (United States)

    Jiménez de Bagüés, María P; Iturralde, María; Arias, Maykel A; Pardo, Julián; Cloeckaert, Axel; Zygmunt, Michel S

    2014-08-01

    Recently, novel atypical Brucella strains isolated from humans and wild rodents have been reported. They are phenotypically close to Ochrobactrum species but belong to the genus Brucella, based on genetic relatedness, although genetic diversity is higher among the atypical Brucella strains than between the classic species. They were classified within or close to the novel species Brucella inopinata. However, with the exception of Brucella microti, the virulence of these novel strains has not been investigated in experimental models of infection. The type species B. inopinata strain BO1 (isolated from a human) and Brucella species strain 83-210 (isolated from a wild Australian rodent) were investigated. A classic infectious Brucella reference strain, B. suis 1330, was also used. BALB/c, C57BL/6, and CD1 mice models and C57BL/6 mouse bone-marrow-derived macrophages (BMDMs) were used as infection models. Strains BO1 and 83-210 behaved similarly to reference strain 1330 in all mouse infection models: there were similar growth curves in spleens and livers of mice and similar intracellular replication rates in BMDMs. However, unlike strain 1330, strains BO1 and 83-210 showed lethality in the 3 mouse models. The novel atypical Brucella strains of this study behave like classic intracellular Brucella pathogens. In addition, they cause death in murine models of infection, as previously published for B. microti, another recently described environmental and wildlife species. © The Author 2014. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  7. Isolation of an H5N8 Highly Pathogenic Avian Influenza Virus Strain from Wild Birds in Seoul, a Highly Urbanized Area in South Korea.

    Science.gov (United States)

    Kwon, Jung-Hoon; Lee, Dong-Hun; Jeong, Jei-Hyun; Yuk, Seong-Su; Erdene-Ochir, Tseren-Ochir; Noh, Jin-Yong; Hong, Woo-Tack; Jeong, Sol; Gwon, Gyeong-Bin; Lee, Sang-Won; Choi, In-Soo; Song, Chang-Seon

    2017-07-01

    Asian-lineage H5 highly pathogenic avian influenza viruses (HPAIV) have caused recurrent outbreaks in poultry and wild birds. In January 2014, H5N8 HPAIV caused outbreaks in South Korea and subsequently spread to East Asia, Europe, and North America. We report the isolation of an H5N8 HPAIV strain from wild birds in Seoul, the most-developed city in South Korea. We analyzed the complete genome sequence of this isolate and estimated its origin using a phylogenetic analysis. The Seoul H5N8 isolate clustered phylogenetically with strains isolated from migratory wild birds but was distinct from Korean poultry isolates. This H5N8 virus was likely introduced into the urbanized city by migratory wild birds. Therefore, wild bird habitats in urbanized areas should be carefully monitored for HPAIV.

  8. Sublethal Ciprofloxacin Treatment Leads to Rapid Development of High-Level Ciprofloxacin Resistance during Long-Term Experimental Evolution of Pseudomonas aeruginosa

    Science.gov (United States)

    Jørgensen, Karin Meinike; Wassermann, Tina; Jensen, Peter Østrup; Hengzuang, Wang; Molin, Søren; Høiby, Niels

    2013-01-01

    The dynamics of occurrence and the genetic basis of ciprofloxacin resistance were studied in a long-term evolution experiment (940 generations) in wild-type, reference strain (PAO1) and hypermutable (PAOΔmutS and PAOMY-Mgm) P. aeruginosa populations continuously exposed to sub-MICs (1/4) of ciprofloxacin. A rapid occurrence of ciprofloxacin-resistant mutants (MIC of ≥12 μg/ml, representing 100 times the MIC of the original population) were observed in all ciprofloxacin-exposed lineages of PAOΔmutS and PAOMY-Mgm populations after 100 and 170 generations, respectively, and in one of the PAO1 lineages after 240 generations. The genetic basis of resistance was mutations in gyrA (C248T and G259T) and gyrB (C1397A). Cross-resistance to beta-lactam antibiotics was observed in the bacterial populations that evolved during exposure to sublethal concentrations of ciprofloxacin. Our study shows that mutants with high-level ciprofloxacin resistance are selected in P. aeruginosa bacterial populations exposed to sub-MICs of ciprofloxacin. This can have implications for the long-term persistence of resistant bacteria and spread of antibiotic resistance by exposure of commensal bacterial flora to low antibiotic concentrations. PMID:23774442

  9. Inactivation of carotenoid-producing and albino strains of Neurospora crassa by visible light, blacklight, and ultraviolet radiation

    International Nuclear Information System (INIS)

    Blanc, P.L.; Tuveson, R.W.; Sargent, M.L.

    1976-01-01

    Suspensions of Neurospora crassa conidia were inactivated by blacklight (BL) radiation (300 to 425 nm) in the absence of exogenous photosensitizing compounds. Carotenoid-containing wild-type conidia were less sensitive to BL radiation than albino conidia, showing a dose enhancement factor (DEF) of 1.2 for dose levels resulting in less than 10 percent survival. The same strains were about equally sensitive to shortwave ultraviolet (uv) inactivation. The kinetics of BL inactivation are similar to those of photodynamic inactivation by visible light in the presence of a photosensitizing dye (methylene blue). Only limited inactivation by visible light in the absence of exogenous photosensitizers was observed. BL and UV inactivations are probably caused by different mechanisms since wild-type conidia are only slightly more resistant to BL radiation (DEF = 1.2 at 1.0 percent survival) than are conidia from a uv-sensitive strain (upr-1, uvs-3). The BL-induced lethal lesions are probably not cyclobutyl pyrimidine dimers since BL-inactivated Haemophilus influenzae transforming deoxyribonucleic acid is not photoreactivated by N. crassa wild-type enzyme extracts, whereas uv-inactivated transforming deoxyribonucleic acid is photoreactivable with this treatment

  10. UV-induced mitotic recombination and its dependence on photoreactivation and liquid holding in the rad6-1 mutant of Saccharomyces cerevisiae

    International Nuclear Information System (INIS)

    Haladus, E.; Zuk, J.

    1980-01-01

    Spontaneous and UV-induced mitotic recombination was compared in diploids homozygous for rad6-1 mutation and in the wild-type strain carrying heterozygous markers for detecting gene conversion (hom 2-1, hom 2-2) and crossing over (ade 1, ade 2). Diploids homozygous for rad6-1 mutation were characterised by an elevated level of spontaneous and UV-induced mitotic recombination, particularly the intergenic events. Exposure of UV-irradiated strains to visible light resulted in an increased survival and decreased level of mitotic recombination. Liquid holding (LH) differentially affected frequency of mitotic intergenic and intragenic recombination in mutant and wild-type strains, being without any significant effect on cell survival. In a mutant strain intragenic recombination is significantly increased, intergenic only slightly. In the wild-type strain intragenic recombination is slightly decreased but intergenic is not changed by LH. Visible light applied after LH had no effect on survival and mitotic recombination in the wild type, while in the mutant strain photoreactivability of survival was fully preserved and accompanied by a decrease in the frequency of intragenic and intergenic recombination. The results suggest that metabolic pathways responsible for restoring cell survival are independent of or only partly overlapping with those concerning recombination events. (orig.) [de

  11. Comparative behaviour of lab.-cultured and wild-type Dacus oleae flies in the field

    International Nuclear Information System (INIS)

    Prokopy, R.J.; Haniotakis, G.E.; Economopoulos, A.P.

    1975-01-01

    Under field conditions, the authors compared the responses of lab.-type (ca. 85 generations under artificial conditions) and wild-type Dacus oleae flies to host plant colour and odour, host fruit colour and shape, small rectangles of different colours and shades, and McPhail-type traps of different colours baited with different odours. Except for the lab.-type flies being relatively more attracted toward red fruit models and small red rectangles and relatively less attracted toward yellow fruit models and small yellow rectangles than the wild type, the qualitative nature of the responses of the two fly types toward the various experimental treatments was essentially the same. Quantitatively, however, consistently smaller percentages of the released lab.-type than the released wild-type flies were recaptured, suggesting that the mobility, flight pattern, or vigour of the two types of flies may be different. (author)

  12. Structure and Composition of Protein Bodies from Wild-Type and High-Lysine Barley Endosperm

    DEFF Research Database (Denmark)

    Ingversen, J.

    1975-01-01

    Protein bodies were isolated from 13 and 28 day old endosperms of barley mutant 1508 and its wild type, Bomi barley. The fine structure of the isolated protein bodies was determined by electron microscopy, and the proteins present in the preparations characterized by amino-acid analysis and SDS......-polyacrylamidegel electrophoresis. Sections through pellets of isolated protein bodies from both the mutant and the wild type revealed protein body structures corresponding with those observed in sections through the intact starchy endosperms. The majority of the wild-type protein bodies was homogeneous spheres accompanied...... that the wild-type protein bodies contained large amounts of prolamines (the storage protein group which is soluble in 55 % isopropanol) and some glutelins (the storage proteins soluble in dilute alkali), whereas the mutant protein bodies have glutelin as the major component and little prolamines...

  13. Phylogenetic analysis of the haemagglutinin gene of canine distemper virus strains detected from breeding foxes, raccoon dogs and minks in China.

    Science.gov (United States)

    Zhao, Jian-Jun; Yan, Xi-Jun; Chai, Xiu-Li; Martella, Vito; Luo, Guo-Liang; Zhang, Hai-Ling; Gao, Han; Liu, Ying-Xue; Bai, Xue; Zhang, Lei; Chen, Tao; Xu, Lei; Zhao, Chun-Fei; Wang, Feng-Xue; Shao, Xi-Qun; Wu, Wei; Cheng, Shi-Peng

    2010-01-06

    Canine distemper virus (CDV) infects a variety of carnivores, including wild and domestic Canidae. Genetic/antigenic heterogeneity has been observed among the various CDV strains, notably in the haemagglutinin (H) gene, that appears as a good target to gather epidemiological information. Based on sequence analysis of the H gene, wild-type CDV strains cluster into distinct geographic lineages (genotypes), irrespective of the species of isolation. The sequence of the H gene of 28 CDV strains detected from both vaccinated and non-vaccinated breeding foxes, raccoon dogs and minks from different geographical areas of China during the years 2004-2008 was determined. All the CDV strains but two (strains HL and HLJ2) were characterized as Asia-1 genotype and were highly similar to each other (96.2-99.7% at the amino acid [aa] level) and to other Asia-1 strains (96.1-99.5% aa) previously detected in China. The CDV strains HL and HLJ2 were both collected from foxes in Heilongjiang province in 2005. Strain HL resembled CDVs of the Arctic genotype (GR88-like) and displayed high aa identity (98.0%) to the Chinese canine strain Liu. By converse, strain HLJ2 was barely related to CDVs of the Asia-2 genotype (88.7-90.3% aa identity), and could represent a novel CDV genotype, tentatively proposed as Asia-3. These results suggest that at least three different CDV genotypes, distantly related (81.8-91.6% aa identity) to the vaccine strains, Onderstepoort-like (America-1 genotype), are currently circulating in breeding foxes, raccoon dogs and minks in China, and that the genotype Asia-1 is predominant. Whether the diversity between wild-type CDVs and the vaccine strains may affect, to some extent, the efficacy of the vaccines deserves further investigations.

  14. Genome sequence of herpes simplex virus 1 strain KOS.

    Science.gov (United States)

    Macdonald, Stuart J; Mostafa, Heba H; Morrison, Lynda A; Davido, David J

    2012-06-01

    Herpes simplex virus type 1 (HSV-1) strain KOS has been extensively used in many studies to examine HSV-1 replication, gene expression, and pathogenesis. Notably, strain KOS is known to be less pathogenic than the first sequenced genome of HSV-1, strain 17. To understand the genotypic differences between KOS and other phenotypically distinct strains of HSV-1, we sequenced the viral genome of strain KOS. When comparing strain KOS to strain 17, there are at least 1,024 small nucleotide polymorphisms (SNPs) and 172 insertions/deletions (indels). The polymorphisms observed in the KOS genome will likely provide insights into the genes, their protein products, and the cis elements that regulate the biology of this HSV-1 strain.

  15. Distribution of sequence-based types of legionella pneumophila serogroup 1 strains isolated from cooling towers, hot springs, and potable water systems in China.

    Science.gov (United States)

    Qin, Tian; Zhou, Haijian; Ren, Hongyu; Guan, Hong; Li, Machao; Zhu, Bingqing; Shao, Zhujun

    2014-04-01

    Legionella pneumophila serogroup 1 causes Legionnaires' disease. Water systems contaminated with Legionella are the implicated sources of Legionnaires' disease. This study analyzed L. pneumophila serogroup 1 strains in China using sequence-based typing. Strains were isolated from cooling towers (n = 96), hot springs (n = 42), and potable water systems (n = 26). Isolates from cooling towers, hot springs, and potable water systems were divided into 25 sequence types (STs; index of discrimination [IOD], 0.711), 19 STs (IOD, 0.934), and 3 STs (IOD, 0.151), respectively. The genetic variation among the potable water isolates was lower than that among cooling tower and hot spring isolates. ST1 was the predominant type, accounting for 49.4% of analyzed strains (n = 81), followed by ST154. With the exception of two strains, all potable water isolates (92.3%) belonged to ST1. In contrast, 53.1% (51/96) and only 14.3% (6/42) of cooling tower and hot spring, respectively, isolates belonged to ST1. There were differences in the distributions of clone groups among the water sources. The comparisons among L. pneumophila strains isolated in China, Japan, and South Korea revealed that similar clones (ST1 complex and ST154 complex) exist in these countries. In conclusion, in China, STs had several unique allelic profiles, and ST1 was the most prevalent sequence type of environmental L. pneumophila serogroup 1 isolates, similar to its prevalence in Japan and South Korea.

  16. Replacement of glycoprotein B gene in the Herpes simplex virus type 1 strain ANGpath DNA that originating from non-pathogenic strain KOS reduces the pathogenicity of recombinant virus

    International Nuclear Information System (INIS)

    Kostal, M.; Bacik, I.; Rajcani, J.; Kaerner, H.C.

    1994-01-01

    Herpes simplex virus type-1 (HSV-1) strain ANGpath and its recombinants, in which the 8.1 kbp BamHI G restriction fragment (0.345-0.399) containing the glycoprotein B (gB path ) gene (UL27) or its sub-fragments-coding either for cytoplasmic or surface domain of gB-had been replaced with the corresponding fragments from non-pathogenic KOS virus DNA (gB KOS ), were tested for their pathogenicity for DBA/2 mice and rabbits. The recombinant ANGpath/B6 KOS prepared by transferring the 2.7 kbp SstI-SstI sub-fragment (0.351-0.368) of the BamHI G KOS fragment still had the original sequence of ANGpath DNA coding for the syn 3 marker in the cytoplasmic domain of gB and was pathogenic for mice as well as for rabbits. Virological and immuno-histological studies in DBA/2 mice infected with the latter pathogenic recombinant and with ANGpath showed the presence of infectious virus and viral antigen at inoculation site (epidermis, subcutaneous connective tissue and striated muscle in the area of right lip), in homo-lateral trigeminal nerve and ganglion, brain stem, midbrain, thalamic and hypothalamic nuclei. In contrast, non-pathogenic recombinants ANGpath/syn + B6 KOS (prepared by transferring the whole BamHI G KOS fragment) and ANGpath/syn +KOS (prepared by transferring the 0.8 kbp BamHI-SstI sub-fragment of the BamHI G KOS fragment) showed limited hematogenous and neural spread, but no evidence of replication in CNS; thus, their behaviour resembled that of the wild type strain KOS. The recombinant ANGpath/syn +KOS , which was not pathogenic for mice, still remained pathogenic for rabbits, a phenomenon indicating the presence of an additional locus in the gB molecule participating on virulence. Sequencing the 1478 bp SstI-SstI sub-fragment of the BamHI G path fragment (nt 53,348 - 54,826 of UL segment) showed the presence of at least 3 mutations as compared to the KOS sequence, from which the change of cytosine at nt 54,2251 altered the codon for arginine to that histidine

  17. Overexpression of ADH1 and HXT1 genes in the yeast Saccharomyces cerevisiae improves the fermentative efficiency during tequila elaboration.

    Science.gov (United States)

    Gutiérrez-Lomelí, Melesio; Torres-Guzmán, Juan Carlos; González-Hernández, Gloria Angélica; Cira-Chávez, Luis Alberto; Pelayo-Ortiz, Carlos; Ramírez-Córdova, Jose de Jesús

    2008-05-01

    This work assessed the effect of the overexpression of ADH1 and HXT1 genes in the Saccharomyces cerevisiae AR5 strain during fermentation of Agave tequilana Weber blue variety must. Both genes were cloned individually and simultaneously into a yeast centromere plasmid. Two transformant strains overexpressing ADH1 and HXT1 individually and one strain overexpressing both genes were randomly selected and named A1, A3 and A5 respectively. Overexpression effect on growth and ethanol production of the A1, A3 and A5 strains was evaluated in fermentative conditions in A. tequilana Weber blue variety must and YPD medium. During growth in YPD and Agave media, all the recombinant strains showed lower cell mass formation than the wild type AR5 strain. Adh enzymatic activity in the recombinant strains A1 and A5 cultivated in A. tequilana and YPD medium was higher than in the wild type. The overexpression of both genes individually and simultaneously had no significant effect on ethanol formation; however, the fermentative efficiency of the A5 strain increased from 80.33% to 84.57% and 89.40% to 94.29% in YPD and Agave medium respectively.

  18. Authentic display of a cholera toxin epitope by chimeric type 1 fimbriae

    DEFF Research Database (Denmark)

    Stentebjerg-Olesen, Bodil; Pallesen, Lars; Jensen, Lars Bogø

    1997-01-01

    . Several of the chosen positions seemed amenable even for large foreign inserts; the chimeric proteins were exposed on the bacterial surface and the cholera toxin epitope was authentically displayed, i.e. it was recognized on bacteria by specific antiserum. Display of chimeric fimbriae was tested...... with respect to host background in three different Escherichia coli strains, i.e. an isogenic set of K-12 strains, differing in the presence of an indigenous fim gene cluster, as well as a wild-type isolate. Immunization of rabbits with purified chimeric fimbriae resulted in serum which specifically recognized...

  19. Near-Infrared Spectroscopy, a Rapid Method for Predicting the Age of Male and Female Wild-Type and Wolbachia Infected Aedes aegypti.

    Directory of Open Access Journals (Sweden)

    Maggy T Sikulu-Lord

    2016-10-01

    Full Text Available Estimating the age distribution of mosquito populations is crucial for assessing their capacity to transmit disease and for evaluating the efficacy of available vector control programs. This study reports on the capacity of the near-infrared spectroscopy (NIRS technique to rapidly predict the ages of the principal dengue and Zika vector, Aedes aegypti. The age of wild-type males and females, and males and females infected with wMel and wMelPop strains of Wolbachia pipientis were characterized using this method. Calibrations were developed using spectra collected from their heads and thoraces using partial least squares (PLS regression. A highly significant correlation was found between the true and predicted ages of mosquitoes. The coefficients of determination for wild-type females and males across all age groups were R2 = 0.84 and 0.78, respectively. The coefficients of determination for the age of wMel and wMelPop infected females were 0.71 and 0.80, respectively (P< 0.001 in both instances. The age of wild-type female Ae. aegypti could be identified as < or ≥ 8 days old with an accuracy of 91% (N = 501, whereas female Ae. aegypti infected with wMel and wMelPop were differentiated into the two age groups with an accuracy of 83% (N = 284 and 78% (N = 229, respectively. Our results also indicate NIRS can distinguish between young and old male wild-type, wMel and wMelPop infected Ae. aegypti with accuracies of 87% (N = 253, 83% (N = 277 and 78% (N = 234, respectively. We have demonstrated the potential of NIRS as a predictor of the age of female and male wild-type and Wolbachia infected Ae. aegypti mosquitoes under laboratory conditions. After field validation, the tool has the potential to offer a cheap and rapid alternative for surveillance of dengue and Zika vector control programs.

  20. Alleviation of glucose repression of maltose metabolism by MIG1 disruption in Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Klein, Christopher; Olsson, Lisbeth; Rønnow, B.

    1996-01-01

    The MIG1 gene was disrupted in a haploid laboratory strain (B224) and in an industrial polyploid strain (DGI 342) of Saccharomyces cerevisiae. The alleviation of glucose repression of the expression of MAL genes and alleviation of glucose control of maltose metabolism were investigated in batch...... cultivations on glucose-maltose mixtures. In the MIG1-disrupted haploid strain, glucose repression was partly alleviated; i.e., maltose metabolism was initiated at higher glucose concentrations than in the corresponding wild-type strain. In contrast, the polyploid Delta mig1 strain exhibited an even more...... stringent glucose control of maltose metabolism than the corresponding wild-type strain, which could be explained by a more rigid catabolite inactivation of maltose permease, affecting the uptake of maltose. Growth on the glucose-sucrose mixture showed that the polyploid Delta mig1 strain was relieved...

  1. Evaluation of [sup 99m]Tc-HM-PAO thigh accumulation in patients with cerebro-vascular disease

    Energy Technology Data Exchange (ETDEWEB)

    Nishigaki, Hiroshi; Adachi, Itaru; Komori, Tsuyoshi; Tatsu, Yoshimitsu; Hisada, Youichi; Sueyoshi, Kouzou; Narabayashi, Isamu (Osaka Medical College, Takatsuki (Japan))

    1993-06-01

    Technetium-99m d,l-hexamethyl-propyleneamine oxime ([sup 99m]Tc-HM-PAO) cerebral SPECT and whole body scintigraphy (WBS) were performed in 5 patients without cerebro-vascular disease (CVD) (Group 1), 31 patients with CVD but not hemiparesis (Group 2) and 18 patients with CVD and hemiparesis (Group 3). Four ROIs were drawn manually around the whole body (WB), brain (Br), right and left thigh (Th). We calculated some ratios: the total counts in the brain over the total counts in the whole body (Br/WB), the total counts in the thigh over the total counts in the whole body (Th/WB) and the mean counts in the thigh over the mean counts in the brain (Th/Br).The Br/WB was 6.9[+-]1.8%, rt-Th/WB was 4.9[+-]2.1%, lt-Th/WB was 5.1[+-]1.3% and Th/Br was 0.46[+-]0.17 in group 1. Whole body scintigraphies in group 1 revealed clear and similar images between right and left thigh. The Br/WB was 6.7[+-]1.4%, Th/WB of paretic side was 4.6[+-]1.0%, Th/WB of non-paretic side was 5.8[+-]1.2% and Th/Br was 0.47[+-]0.18 in group 3. The Th/WB in non paretic side was significantly higher than that in paretic side (p<0.01). The thigh images in group 3 revealed clear differences between paretic and non-paretic thighes. In conclusion we could acquire the clear thigh images with [sup 99m]Tc-HM-PAO. It was possible that we evaluated not only cerebral perfusion but also muscle atrophy and/or perfusion in patients with CVD using [sup 99m]Tc-HM-PAO. (author).

  2. Abscisic Acid Negatively Regulates Elicitor-Induced Synthesis of Capsidiol in Wild Tobacco1[W

    Science.gov (United States)

    Mialoundama, Alexis Samba; Heintz, Dimitri; Debayle, Delphine; Rahier, Alain; Camara, Bilal; Bouvier, Florence

    2009-01-01

    In the Solanaceae, biotic and abiotic elicitors induce de novo synthesis of sesquiterpenoid stress metabolites known as phytoalexins. Because plant hormones play critical roles in the induction of defense-responsive genes, we have explored the effect of abscisic acid (ABA) on the synthesis of capsidiol, the major wild tobacco (Nicotiana plumbaginifolia) sesquiterpenoid phytoalexin, using wild-type plants versus nonallelic mutants Npaba2 and Npaba1 that are deficient in ABA synthesis. Npaba2 and Npaba1 mutants exhibited a 2-fold higher synthesis of capsidiol than wild-type plants when elicited with either cellulase or arachidonic acid or when infected by Botrytis cinerea. The same trend was observed for the expression of the capsidiol biosynthetic genes 5-epi-aristolochene synthase and 5-epi-aristolochene hydroxylase. Treatment of wild-type plants with fluridone, an inhibitor of the upstream ABA pathway, recapitulated the behavior of Npaba2 and Npaba1 mutants, while the application of exogenous ABA reversed the enhanced synthesis of capsidiol in Npaba2 and Npaba1 mutants. Concomitant with the production of capsidiol, we observed the induction of ABA 8′-hydroxylase in elicited plants. In wild-type plants, the induction of ABA 8′-hydroxylase coincided with a decrease in ABA content and with the accumulation of ABA catabolic products such as phaseic acid and dihydrophaseic acid, suggesting a negative regulation exerted by ABA on capsidiol synthesis. Collectively, our data indicate that ABA is not required per se for the induction of capsidiol synthesis but is essentially implicated in a stress-response checkpoint to fine-tune the amplification of capsidiol synthesis in challenged plants. PMID:19420326

  3. Effect of wild-type Shigella species and attenuated Shigella vaccine candidates on small intestinal barrier function, antigen trafficking, and cytokine release.

    Directory of Open Access Journals (Sweden)

    Maria Fiorentino

    Full Text Available Bacterial dysentery due to Shigella species is a major cause of morbidity and mortality worldwide. The pathogenesis of Shigella is based on the bacteria's ability to invade and replicate within the colonic epithelium, resulting in severe intestinal inflammatory response and epithelial destruction. Although the mechanisms of pathogenesis of Shigella in the colon have been extensively studied, little is known on the effect of wild-type Shigella on the small intestine and the role of the host response in the development of the disease. Moreover, to the best of our knowledge no studies have described the effects of apically administered Shigella flexneri 2a and S. dysenteriae 1 vaccine strains on human small intestinal enterocytes. The aim of this study was to assess the coordinated functional and immunological human epithelial responses evoked by strains of Shigella and candidate vaccines on small intestinal enterocytes. To model the interactions of Shigella with the intestinal mucosa, we apically exposed monolayers of human intestinal Caco2 cells to increasing bacterial inocula. We monitored changes in paracellular permeability, examined the organization of tight-junctions and the pro-inflammatory response of epithelial cells. Shigella infection of Caco2 monolayers caused severe mucosal damage, apparent as a drastic increase in paracellular permeability and disruption of tight junctions at the cell-cell boundary. Secretion of pro-inflammatory IL-8 was independent of epithelial barrier dysfunction. Shigella vaccine strains elicited a pro-inflammatory response without affecting the intestinal barrier integrity. Our data show that wild-type Shigella infection causes a severe alteration of the barrier function of a small intestinal cell monolayer (a proxy for mucosa and might contribute (along with enterotoxins to the induction of watery diarrhea. Diarrhea may be a mechanism by which the host attempts to eliminate harmful bacteria and transport them

  4. Cerebral blood flow imaging by I-123 IMP and Tc-99m HM-PAO

    Energy Technology Data Exchange (ETDEWEB)

    Uno, Koichi; Yoshikawa, Kyosan; Minoshima, Satoshi; Imaseki, Keiko; Arimizu, Noboru; Yamaura, Akira; Uematsu, Sadao

    1988-02-01

    SPECT studies with either N-isopropyl-p-(I-123)iodo- amphetamine (I-123 IMP) or Tc-99m hexamethyl propylene amine oxime (Tc-99m HM-PAO) were cuncurrently performed in 12 patients with brain disorders, comprising cerebral infarction (7), cerebral aneurysm (one), intracranial hemorrhage (3), and subdural hematoma (one). Whereas I-123 IMP was taken up gradually into the brain, the uptake of Tc-99m-HM-PAO in the brain reached the peak immediately after the iv injection, with 90% or more remaining constant by 15 min postinjection. On early SPECT images, a high uptake of I-123 IMP was observed in the lung, and the uptake of Tc-99m HM-PAO was observed as well in the soft tissue of cervical region. In all patients except for one, decreased rCBF was observed in the lesions on both I-123 and Tc-99m SPECT scans. Both of the radiopharmaceuticals were analogous in that decreased blood flow corresponded to cerebral lesions. (Namekawa, K).

  5. Research on the ultrafast fluorescence property of thylakoid membranes of the wild-type and mutant rice

    Science.gov (United States)

    Ren, Zhao-Yu; Xu, Xiao-Ming; Wang, Shui-Cai; Xin, Yue-Yong; He, Jun-Fang; Hou, Xun

    2003-10-01

    A high yielding rice variety mutant (Oryza sativa L., Zhenhui 249) with low chlorophyll b (Chl b) has been discovered in natural fields. It has a quality character controlled by a pair of recessive genes (nuclear gene). The partial loss of Chl b in content affects the efficiency of light harvest in a light harvest complex (LHC), thus producing the difference of the exciting energy transfer and the efficiency of photochemistry conversion between the mutant and wild-type rice in photosynthetic unit. The efficiency of utilizing light energy is higher in the mutant than that in the wild-type rice relatively. For further discussion of the above-mentioned difference and learning about the mechanism of the increase in the photochemical efficiency of the mutant, the pico-second resolution fluorescence spectrum measurement with delay-frame-scanning single photon counting technique is adopted. Thylakoid membranes of the mutant and the wild-type rice are excited by an Ar+ laser with a pulse width of 120 ps, repetition rate of 4 MHz and wavelength of 514 nm. Compared with the time and spectrum property of exciting fluorescence, conclusions of those ultrafast dynamic experiments are: 1) The speeds of the exciting energy transferred in photo-system I are faster than that in photo-system II in both samples. 2) The speeds of the exciting energy transfer of mutant sample are faster than those of the wild-type. This might be one of the major reasons why the efficiency of photosynthesis is higher in mutant than that in the wild-type rice.

  6. Selected wild strains of Agaricus bisporus produce high yields of mushrooms at 25°C.

    Science.gov (United States)

    Navarro, Pilar; Savoie, Jean-Michel

    2015-01-01

    To cultivate the button mushroom Agaricus bisporus in warm countries or during summer in temperate countries, while saving energy, is a challenge that could be addressed by using the biological diversity of the species. The objective was to evaluate the yield potential of eight wild strains previously selected in small scale experiments for their ability to produce mature fruiting bodies at 25°C and above. Culture units of 8 kg of compost were used. The yield expressed as weight or number per surface unit and earliness of fruiting were recorded during cultivation in climatic rooms at 17, 25 or 30°C. Only strains of A. bisporus var. burnettii were able to fruit at 30°C. At 25°C they produced the highest yields (27 kg m(-2)) and had best earliness. The yields at 25°C for the strains of A. bisporus var. bisporus ranged from 12 to 16 kg m(-2). The yield ratios 25°C/17°C ranged from 0.8 to 1.2. The variety burnettii originated in the Sonoran Desert in California showed adaptation for quickly producing fruiting bodies at high temperature when humidity conditions were favorable. Strains of the variety bisporus showed interesting potentials for their ability to produce mature fruiting bodies at higher temperature than present cultivars and might be used in breeding programs. Copyright © 2012 Revista Iberoamericana de Micología. Published by Elsevier Espana. All rights reserved.

  7. Lethal effect of short-wave (254 nm) UV-radiation on cells of Chlamidomonas reinhardii strains with different carotenoid content

    International Nuclear Information System (INIS)

    Kamchatova, I.E.; Chunaev, A.S.; Bronnikov, V.A.

    1987-01-01

    In experiments on related Chlamidomonas reinhardii strains of similar mating type a study was made of sensitivity of cells with different carotenoid content to UV-radiation of 254 nm. Mutants having a lower, as opposed to the wild type strain, content of carotenoids exhibited an increased radiosensitivity. A carotenoid-free mutant was found to possess a higher sensitivity to UV-radiation which was typical of the strain with the impaired excision repair system. The studied subclone of the UV-radiosensitive strain CC-888 was unable to photoreactivate the UV-induced damages which was typical of the wild-type strain. The content of carotenoids in cells of this subnuclone exceeded that in cells of mutants with the reduced pigmentation

  8. Diagnosis of infected bone and joint diseases with 99mTc-HM-PAO labeled leukocytes

    International Nuclear Information System (INIS)

    Kanegae, Kakuko; Itoh, Kazuo; Tsukamoto, Eriko; Nagao, Kazuhiko; Nakada, Kunihiro; Hurudate, Masayori

    1992-01-01

    The usefulness of 99m Tc-hexamethylpropylene amine oxime (HM-PAO) labeled leukocytes scans was studied in 15 patients with suspected infection of the bone and joints. All spot images of lesions were obtained 4 and 24 hours after injection of 70.3-236.8 MBq (a mean, 149.5 MBq). 99m Tc-HM-PAO leukocytes scans were positive in 5 patients, negative in 8, and equivocal in 2. It had a sensitivity of 83% (5/6), specificity of 100% (6/6), and accuracy of 93% (14/15) for diagnosing infections. Equivocal uptake, seen on the 4-hr image in 2 patients, became negative on the 24-hr image. In view of ready availability and simple labeling procedure, 99m Tc-HM-PAO labeled leukocytes scans can be used as one of the specific diagnostic procedures for infections. (N.K.)

  9. Detection and molecular characterization of J subgroup avian leukosis virus in wild ducks in China.

    Science.gov (United States)

    Zeng, Xiangwei; Liu, Lanlan; Hao, Ruijun; Han, Chunyan

    2014-01-01

    To assess the status of avian leukosis virus subgroup J (ALV-J) in wild ducks in China, we examined samples from 528 wild ducks, representing 17 species, which were collected in China over the past 3 years. Virus isolation and PCR showed that 7 ALV-J strains were isolated from wild ducks. The env genes and the 3'UTRs from these isolates were cloned and sequenced. The env genes of all 7 wild duck isolates were significantly different from those in the prototype strain HPRS-103, American strains, broiler ALV-J isolates and Chinese local chicken isolates, but showed close homology with those found in some layer chicken ALV-J isolates and belonged to the same group. The 3'UTRs of 7 ALV-J wild ducks isolates showed close homology with the prototype strain HPRS-103 and no obvious deletion was found in the 3'UTR except for a 1 bp deletion in the E element that introduced a binding site for c-Ets-1. Our study demonstrated the presence of ALV-J in wild ducks and investigated the molecular characterization of ALV-J in wild ducks isolates.

  10. A proteomics approach to study synergistic and antagonistic interactions of the fungal-bacterial consortium Fusarium oxysporum wild-type MSA 35.

    Science.gov (United States)

    Moretti, Marino; Grunau, Alexander; Minerdi, Daniela; Gehrig, Peter; Roschitzki, Bernd; Eberl, Leo; Garibaldi, Angelo; Gullino, Maria Lodovica; Riedel, Kathrin

    2010-09-01

    Fusarium oxysporum is an important plant pathogen that causes severe damage of many economically important crop species. Various microorganisms have been shown to inhibit this soil-borne plant pathogen, including non-pathogenic F. oxysporum strains. In this study, F. oxysporum wild-type (WT) MSA 35, a biocontrol multispecies consortium that consists of a fungus and numerous rhizobacteria mainly belonging to gamma-proteobacteria, was analyzed by two complementary metaproteomic approaches (2-DE combined with MALDI-Tof/Tof MS and 1-D PAGE combined with LC-ESI-MS/MS) to identify fungal or bacterial factors potentially involved in antagonistic or synergistic interactions between the consortium members. Moreover, the proteome profiles of F. oxysporum WT MSA 35 and its cured counter-part CU MSA 35 (WT treated with antibiotics) were compared with unravel the bacterial impact on consortium functioning. Our study presents the first proteome mapping of an antagonistic F. oxysporum strain and proposes candidate proteins that might play an important role for the biocontrol activity and the close interrelationship between the fungus and its bacterial partners.

  11. HM-PAO-SPECT of the brain in a new-born child

    Energy Technology Data Exchange (ETDEWEB)

    Gruenwald, F.; Biersack, H.J.; Bindl, L.

    1988-08-01

    HM-PAO-SPECT of the brain was performed in a 14 days old new-born child. Diencephalon, brain stem and cerebellum showed a relative high tracer accumulation; there was nearly no accumulation in the neocortex.

  12. Modeling options to manage type 1 wild poliovirus imported into Israel in 2013.

    Science.gov (United States)

    Kalkowska, Dominika A; Duintjer Tebbens, Radboud J; Grotto, Itamar; Shulman, Lester M; Anis, Emilia; Wassilak, Steven G F; Pallansch, Mark A; Thompson, Kimberly M

    2015-06-01

    After 25 years without poliomyelitis cases caused by circulating wild poliovirus (WPV) in Israel, sewage sampling detected WPV type 1 (WPV1) in April 2013, despite high vaccination coverage with only inactivated poliovirus vaccine (IPV) since 2005. We used a differential equation-based model to simulate the dynamics of poliovirus transmission and population immunity in Israel due to past exposure to WPV and use of oral poliovirus vaccine (OPV) in addition to IPV. We explored the influences of various immunization options to stop imported WPV1 circulation in Israel. We successfully modeled the potential for WPVs to circulate without detected cases in Israel. Maintaining a sequential IPV/OPV schedule instead of switching to an IPV-only schedule in 2005 would have kept population immunity high enough in Israel to prevent WPV1 circulation. The Israeli response to WPV1 detection prevented paralytic cases; a more rapid response might have interrupted transmission more quickly. IPV-based protection alone might not provide sufficient population immunity to prevent poliovirus transmission after an importation. As countries transition to IPV in immunization schedules, they may need to actively manage population immunity and consider continued use of OPV, to avoid the potential circulation of imported live polioviruses before globally coordinated cessation of OPV use. © The Author 2014. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  13. Cerebral uptake and retention of 99Tcsup(m)-hexamethylpropyleneamine oxime (99Tcsup(m)-HM-PAO)

    International Nuclear Information System (INIS)

    Holmes, R.A.; Chaplin, S.B.; Royston, K.G.; Missouri Univ., Columbia

    1985-01-01

    A new radiopharmaceutical, 99 Tcsup(m)-hexamethylpropyleneamine oxime ( 99 Tcsup(m)-HM-PAO) is described. This agent displays considerable promise for imaging cerebral blood flow. In studies in rats and one human volunteer, 99 Tcsup(m)-HM-PAO demonstrates good brain uptake, prolonged retention of activity in the brain, and slow regional redistribution. These properties suggest that this new radiopharmaceutical is ideal for single photon emission tomographic (SPECT) imaging of cerebral blood flow. (author)

  14. Increased transient receptor potential vanilloid type 1 (TRPV1) channel expression in hypertrophic heart

    DEFF Research Database (Denmark)

    Thilo, Florian; Liu, Ying; Schulz, Nico

    2010-01-01

    The aim of this study was to compare the expression of transient receptor potential vanilloid type 1 (TRPV1) channels in hypertrophic hearts from transgenic mice showing overexpression of the catalytic subunit alpha of protein phosphatase 2A alpha (PP2Ac alpha) with wild-type mice and with TRPV1-...... alpha transgenic mice compared to wild-type mice and TRPV1-/- mice (8.6±1.3mg/g; 5.4±0.3mg/g; and 5.4±0.4mg/g; respectively; p...

  15. [Construction and characterization of an epitope-mutated Asia 1 type foot-and-mouth disease virus].

    Science.gov (United States)

    Zhang, Yan; Hu, Yonghao; Yang, Fan; Yang, Bo; Wang, Songhao; Zhu, Zixiang; Zheng, Haixue

    2015-01-01

    To generate an epitope-mutated foot-and-mouth disease virus (FMDV) as a marker vaccine, the infectious clone pAsia 1-FMDV containing the complete genomic cDNA of Asia 1 type FMDV was used as backbone, the residues at positions 27 and 31 in the 3D gene were mutated (H27Y and N31R). The resulting plasmid pAsia 1-FMDV-3DM encoding a mutated epitope was transfected into BHK-21 cells and the recombinant virus rAsia 1-3DM was rescued. The recombinant virus showed similar biological characteristics comparable with the parental virus. In serological neutralization test the antisera against recombine virus have a good reactivity with parental virus. The antisera against the mutant virus were shown to be reactive with the mutated epitope but not the wild-type one. The results indicated that the two virus strains could be distinguished by western blotting using synthetic peptides. This epitope-mutated FMDV strain will be evaluated as a potential marker vaccine against FMDV infections.

  16. Gene expression profiling in wild-type and metallothionein mutant fibroblast cell lines

    Directory of Open Access Journals (Sweden)

    ÁNGELA D ARMENDÁRIZ

    2006-01-01

    Full Text Available The role of metallothioneins (MT in copper homeostasis is of great interest, as it appears to be partially responsible for the regulation of intracellular copper levels during adaptation to extracellular excess of the metal. To further investigate a possible role of MTs in copper metabolism, a genomics approach was utilized to evaluate the role of MT on gene expression. Microarray analysis was used to examine the effects of copper overload in fibroblast cells from normal and MT I and II double knock-out mice (MT-/-. As a first step, we compared genes that were significantly upregulated in wild-type and MT-/- cells exposed to copper. Even though wild-type and mutant cells are undistinguishable in terms of their morphological features and rates of growth, our results show that MT-/- cells do not respond with induction of typical markers of cellular stress under copper excess conditions, as observed in the wild-type cell line, suggesting that the transcription initiation rate or the mRNA stability of stress genes is affected when there is an alteration in the copper store capacity. The functional classification of other up-regulated genes in both cell lines indicates that a large proportion (>80% belong to two major categories: 1 metabolism; and 2 cellular physiological processes, suggesting that at the transcriptional level copper overload induces the expression of genes associated with diverse molecular functions. These results open the possibility to understand how copper homeostasis is being coordinated with other metabolic pathways.

  17. Molecular epidemiology of Mycoplasma hyopneumoniae from outbreaks of enzootic pneumonia in domestic pig and the role of wild boar.

    Science.gov (United States)

    Kuhnert, Peter; Overesch, Gudrun

    2014-11-07

    Mycoplasma hyopneumoniae is the major cause of enzootic pneumonia (EP) in domestic pigs, a disease with low mortality but high morbidity, having a great economic impact for producers. In Switzerland EP has been successfully eradicated, however, sporadic outbreaks are observed with no obvious source. Besides the possibility of recurrent outbreaks due to persisting M. hyopneumoniae strains within the pig population, there is suspicion that wild boars might introduce M. hyopneumoniae into swine herds. To elucidate possible links between domestic pig and wild boar, epidemiological investigations of recent EP outbreaks were initiated and lung samples of pig and wild boar were tested for the presence of specific genotypes by multilocus sequence typing (MLST). Despite generally different genotypes in wild boar, outbreak strains could be found in geographically linked wild boar lungs after, but so far not before the outbreak. Recurrent outbreaks in a farm were due to the same strain, indicating unsuccessful sanitation rather than reintroduction by wild boar. In another case outbreaks in six different farms were caused by the same strain never found in wild boar, confirming spread between farms due to hypothesized animal transport. Results indicate the presence of identical lineages of wild boar and domestic pig strains, and possible transmission of M. hyopneumoniae between wild boar and pig. However, the role of wild boar might be rather one as a recipient than a transmitter. More important than contact to wild boar for sporadic outbreaks in Switzerland is apparently persistence of M. hyopneumoniae within a farm as well as transmission between farms. Copyright © 2014 Elsevier B.V. All rights reserved.

  18. Comparative usage of herpesvirus entry mediator A and nectin-1 by laboratory strains and clinical isolates of herpes simplex virus

    International Nuclear Information System (INIS)

    Krummenacher, Claude; Baribaud, Frederic; Ponce de Leon, Manuel; Baribaud, Isabelle; Whitbeck, J. Charles; Xu Ruliang; Cohen, Gary H.; Eisenberg, Roselyn J.

    2004-01-01

    The herpesvirus entry mediator A (HVEM/HveA) and nectin-1 (HveC/CD111) are two major receptors for herpes simplex virus (HSV). Although structurally unrelated, both receptors can independently mediate entry of wild-type (wt) HSV-1 and HSV-2 by interacting with the viral envelope glycoprotein D (gD). Laboratory strains with defined mutations in gD (e.g. rid1) do not use HVEM but use nectin-2 (HveB/CD112) for entry. The relative usage of HVEM and nectin-1 during HSV infection in vivo is not known. In the absence of a defined in vivo model, we used in vitro approaches to address this question. First, we screened HSV clinical isolates from various origins for receptor tropism and found that all used both HVEM and nectin-1. Second, we determined the numbers of surface receptors on various susceptible and resistant cell lines as well as on primary fibroblasts derived from an individual with cleft lip/palate ectodermal dysplasia (CLPED1). Although CLPED1 cells can only express a defective form of nectin-1, they allowed entry of wild type and mutant HSV strains by usage of either HVEM or nectin-2. Finally, we compared the ability of HVEM and nectin-1 to mediate entry when expressed at varying cell surface densities. Both receptors showed a direct relationship between the number of receptors and HSV susceptibility. Direct comparison of receptors suggests that nectin-1 is more efficient at promoting entry than HVEM. Overall, our data suggest that both receptors play a role during HSV infection in vivo and that both are highly efficient even at low levels of expression

  19. Mating competitiveness of sterile genetic sexing strain males (GAMA) under laboratory and semi-field conditions: Steps towards the use of the Sterile Insect Technique to control the major malaria vector Anopheles arabiensis in South Africa.

    Science.gov (United States)

    Munhenga, Givemore; Brooke, Basil D; Gilles, Jeremie R L; Slabbert, Kobus; Kemp, Alan; Dandalo, Leonard C; Wood, Oliver R; Lobb, Leanne N; Govender, Danny; Renke, Marius; Koekemoer, Lizette L

    2016-03-02

    Anopheles arabiensis Patton is primarily responsible for malaria transmission in South Africa after successful suppression of other major vector species using indoor spraying of residual insecticides. Control of An. arabiensis using current insecticide based approaches is proving difficult owing to the development of insecticide resistance, and variable feeding and resting behaviours. The use of the sterile insect technique as an area-wide integrated pest management system to supplement the control of An. arabiensis was proposed for South Africa and is currently under investigation. The success of this technique is dependent on the ability of laboratory-reared sterile males to compete with wild males for mates. As part of the research and development of the SIT technique for use against An. arabiensis in South Africa, radio-sensitivity and mating competitiveness of a local An. arabiensis sexing strain were assessed. The optimal irradiation dose inducing male sterility without compromising mating vigour was tested using Cobalt 60 irradiation doses ranging from 70-100 Gy. Relative mating competitiveness of sterile laboratory-reared males (GAMA strain) compared to fertile wild-type males (AMAL strain) for virgin wild-type females (AMAL) was investigated under laboratory and semi-field conditions using large outdoor cages. Three different sterile male to fertile male to wild-type female ratios were evaluated [1:1:1, 5:1:1 and 10:1:1 (sterile males: fertile, wild-type males: fertile, wild-type females)]. Irradiation at the doses tested did not affect adult emergence but had a moderate effect on adult survivorship and mating vigour. A dose of 75 Gy was selected for the competitiveness assays. Mating competitiveness experiments showed that irradiated GAMA male mosquitoes are a third as competitive as their fertile AMAL counterparts under semi-field conditions. However, they were not as competitive under laboratory conditions. An inundative ratio of 10:1 induced the

  20. Sex-Specific Diurnal Immobility Induced by Forced Swim Test in Wild Type and Clock Gene Deficient Mice

    Directory of Open Access Journals (Sweden)

    Ningyue Li

    2015-03-01

    Full Text Available Objective: The link between alterations in circadian rhythms and depression are well established, but the underlying mechanisms are far less elucidated. We investigated the circadian characteristics of immobility behavior in wild type (WT mice and mice with mutations in core Clock genes. Methods: All mice were tested with forced swim test (FST at 4 h intervals. Results: These experiments revealed significant diurnal rhythms associated with immobility behavior in both male and female WT mice with sex-different circadian properties. In addition, male mice showed significantly less immobility during the night phase in comparison to female mice. Female Per1Brdm1 mice also showed significant rhythmicity. However, the timing of rhythmicity was very different from that observed in female wild type mice. Male Per1Brdm1 mice showed a pattern of rhythmicity similar to that of wild type mice. Furthermore, female Per1Brdm1 mice showed higher duration of immobility in comparison to male Per1Brdm1 mice in both daytime and early night phases. Neither Per2Brdm1 nor ClockΔ19 mice showed significant rhythmicity, but both female Per2Brdm1 and ClockΔ19 mice had lower levels of immobility, compared to males. Conclusions: This study highlights the differences in the circadian characteristics of immobility induced by FST in WT, ClockΔ19, Per1, and Per2 deficient mice.

  1. Extraction of [99mTc]-d,l-HM-PAO across the blood-brain barrier

    DEFF Research Database (Denmark)

    Andersen, A R; Friberg, H; Knudsen, K B

    1988-01-01

    The initial extraction (E) across the blood-brain barrier (BBB) of [99mTc]-d,l-HM-PAO after intracarotid injection was measured in 14 Wistar rats and 6 patients using the double indicator, single injection method with Na-24 as the cotracer. In both series, cerebral blood flow (CBF) was measured...... was increased from 20 to 120 microliters, while using a 120 microliters bolus containing 10% albumin resulted in a decrease in E. This suggests that HM-PAO binding to albumin is not totally and rapidly reversible during a single passage through brain capillaries and that binding to blood elements may reduce...... the apparent extraction across brain capillaries. In patients using a bolus of 1 ml saline, E decreased linearly with increasing CBF (r = -0.81, p less than 0.001). For a CBF of 0.59 ml/g/min and an average apparent E of 0.72, an apparent PS product of 0.76 ml/g/min was calculated.(ABSTRACT TRUNCATED AT 250...

  2. Exploratory biomarker analysis for treatment response in KRAS wild type metastatic colorectal cancer patients who received cetuximab plus irinotecan

    International Nuclear Information System (INIS)

    Kim, Seung Tae; Ahn, Tae Jin; Lee, Eunjin; Do, In-Gu; Lee, Su Jin; Park, Se Hoon; Park, Joon Oh; Park, Young Suk; Lim, Ho Yeong; Kang, Won Ki; Kim, Suk Hyeong; Lee, Jeeyun; Kim, Hee Cheol

    2015-01-01

    More than half of the patients selected based on KRAS mutation status fail to respond to the treatment with cetuximab in metastatic colorectal cancer (mCRC). We designed a study to identify additional biomarkers that could act as indicators for cetuximab treatment in mCRC. We investigated 58 tumor samples from wild type KRAS CRC patients treated with cetuximab plus irinotecan (CI). We conducted the genotyping for mutations in either BRAF or PIK3CA and profiled comprehensively the expression of 522 kinase genes. BRAF mutation was detected in 5.1 % (3/58) of patients. All 50 patients showed wild type PIK3CA. Gene expression patterns that categorized patients with or without the disease control to CI were compared by supervised classification analysis. PSKH1, TLK2 and PHKG2 were overexpressed significantly in patients with the disease control to IC. The higher expression value of PSKH1 (r = 0.462, p < 0.001) and TLK2 (r = 0.361, p = 0.005) had the significant correlation to prolonged PFS. The result of this work demonstrated that expression nature of kinase genes such as PSKH1, TLK2 and PHKG2 may be informative to predict the efficacy of CI in wild type KRAS CRC. Mutations in either BRAF or PIK3CA were rare subsets in wild type KRAS CRC

  3. Anti-quorum sensing activity of Psidium guajava L. flavonoids against Chromobacterium violaceum and Pseudomonas aeruginosa PAO1.

    Science.gov (United States)

    Vasavi, Halkare Suryanarayana; Arun, Ananthapadmanabha Bhagwath; Rekha, Punchapady-Devasya

    2014-05-01

    Psidium guajava L., which has been used traditionally as a medicinal plant, was explored for anti-quorum sensing (QS) activity. The anti-QS activity of the flavonoid (FL) fraction of P. guajava leaves was determined using a biosensor bioassay with Chromobacterium violaceum CV026. Detailed investigation of the effects of the FL-fraction on QS-regulated violacein production in C. violaceum ATCC12472 and pyocyanin production, proteolytic, elastolytic activities, swarming motility and biofilm formation in Pseudomonas aeruginosa PAO1 was performed using standard methods. Possible mechanisms of QS-inhibition were studied by assessing violacein production in response to N-acyl homoserine lactone (AHL) synthesis in the presence of the FL-fraction in C. violaceum ATCC31532 and by evaluating the induction of violacein in the mutant C. violaceum CV026 by AHL extracted from the culture supernatants of C. violaceum 31532. Active compounds in the FL-fraction were identified by liquid chromatography-mass spectrometry (LC-MS). Inhibition of violacein production by the FL-fraction in a C. violaceum CV026 biosensor bioassay indicated possible anti-QS activity. The FL-fraction showed concentration-dependent decreases in violacein production in C. violaceum 12472 and inhibited pyocyanin production, proteolytic and elastolytic activities, swarming motility and biofilm formation in P. aeruginosa PAO1. Interestingly, the FL-fraction did not inhibit AHL synthesis; AHL extracted from cultures of C. violaceum 31532 grown in the presence of the FL-fraction induced violacein in the mutant C. violaceum CV026. LC-MS analysis revealed the presence of quercetin and quercetin-3-O-arabinoside in the FL-fraction. Both quercetin and quercetin-3-O-arabinoside inhibited violacein production in C. violaceum 12472, at 50 and 100 μg/mL, respectively. Results of this study provide scope for further research to exploit these active molecules as anti-QS agents. © 2014 The Societies and Wiley Publishing

  4. A Ten-Week Biochemistry Lab Project Studying Wild-Type and Mutant Bacterial Alkaline Phosphatase

    Science.gov (United States)

    Witherow, D. Scott

    2016-01-01

    This work describes a 10-week laboratory project studying wild-type and mutant bacterial alkaline phosphatase, in which students purify, quantitate, and perform kinetic assays on wild-type and selected mutants of the enzyme. Students also perform plasmid DNA purification, digestion, and gel analysis. In addition to simply learning important…

  5. The amyR-deletion strain of Aspergillus niger CICC2462 is a suitable host strain to express secreted protein with a low background.

    Science.gov (United States)

    Zhang, Hui; Wang, Shuang; Zhang, Xiang Xiang; Ji, Wei; Song, Fuping; Zhao, Yue; Li, Jie

    2016-04-28

    The filamentous fungus Aspergillus niger is widely exploited as an important expression host for industrial production. The glucoamylase high-producing strain A. niger CICC2462 has been used as a host strain for the establishment of a secretion expression system. It expresses recombinant xylanase, mannase and asparaginase at a high level, but some high secretory background proteins in these recombinant strains still remain, such as alpha-amylase and alpha-glucosidase; lead to a low-purity of fermentation products. The aim was to construct an A. niger host strain with a low background of protein secretion. The transcription factor amyR was deleted in A. niger CICC2462, and the results from enzyme activity assays and SDS-PAGE analysis showed that the glucoamylase and amylase activities of the ∆amyR strains were significantly lower than those of the wild-type strain. High-throughput RNA-sequencing and shotgun LC-MS/MS proteomic technology analysis demonstrated that the expression of amylolytic enzymes was decreased at both the transcriptional and translational levels in the ∆amyR strain. Interestingly, the ∆amyR strain growth rate better than the wild-type strain. Our findings clearly indicated that the ∆amyR strain of A. niger CICC2462 can be used as a host strain with a low background of protein secretion.

  6. A cerato-platanin protein SsCP1 targets plant PR1 and contributes to virulence of Sclerotinia sclerotiorum

    DEFF Research Database (Denmark)

    Yang, Guogen; Tang, Liguang; Gong, Yingdi

    2018-01-01

    in the apoplast to facilitate infection by S. sclerotiorum. Overexpressing PR1 enhanced resistance to the wild-type strain, but not to the Sscp1 knockout strain of S. sclerotiorum. Sscp1-expressing transgenic plants showed increased concentrations of salicylic acid (SA) and higher levels of resistance to several...

  7. Mutations in the Atp1p and Atp3p subunits of yeast ATP synthase differentially affect respiration and fermentation in Saccharomyces cerevisiae.

    Science.gov (United States)

    Francis, Brian R; White, Karen H; Thorsness, Peter E

    2007-04-01

    ATP1-111, a suppressor of the slow-growth phenotype of yme1Delta lacking mitochondrial DNA is due to the substitution of phenylalanine for valine at position 111 of the alpha-subunit of mitochondrial ATP synthase (Atp1p in yeast). The suppressing activity of ATP1-111 requires intact beta (Atp2p) and gamma (Atp3p) subunits of mitochondrial ATP synthase, but not the stator stalk subunits b (Atp4p) and OSCP (Atp5p). ATP1-111 and other similarly suppressing mutations in ATP1 and ATP3 increase the growth rate of wild-type strains lacking mitochondrial DNA. These suppressing mutations decrease the growth rate of yeast containing an intact mitochondrial chromosome on media requiring oxidative phosphorylation, but not when grown on fermentable media. Measurement of chronological aging of yeast in culture reveals that ATP1 and ATP3 suppressor alleles in strains that contain mitochondrial DNA are longer lived than the isogenic wild-type strain. In contrast, the chronological life span of yeast cells lacking mitochondrial DNA and containing these mutations is shorter than that of the isogenic wild-type strain. Spore viability of strains bearing ATP1-111 is reduced compared to wild type, although ATP1-111 enhances the survival of spores that lacked mitochondrial DNA.

  8. Comparison of the Tastes of L-Alanine and Monosodium Glutamate in C57BL/6J Wild Type and T1r3 Knockout Mice.

    Science.gov (United States)

    Eddy, Meghan C; Eschle, Benjamin K; Delay, Eugene R

    2017-09-01

    Previous research showed that L-alanine and monosodium L-glutamate elicit similar taste sensations in rats. This study reports the results of behavioral experiments designed to compare the taste capacity of C57BL/6J wild type and T1r3- mice for these 2 amino acids. In conditioned taste aversion (CTA) experiments, wild-type mice exhibited greater sensitivity than knockout mice for both L-amino acids, although knockout mice were clearly able to detect both amino acids at 50 mM and higher concentrations. Generalization of CTA between L-alanine and L-glutamate was bidirectionally equivalent for both mouse genotypes, indicating that both substances elicited similar tastes in both genotypes. This was verified by the discrimination experiments in which both mouse genotypes performed at or near chance levels at 75 and 150 mM. Above 150 mM, discrimination performance improved, suggesting the taste qualities of the 2 L-amino acids are not identical. No differences between knockout and wild-type mice in discrimination ability were detected. These results indicate that while the T1r3 receptor is important for tasting L-alanine and L-glutamate, other receptors are also important for tasting these amino acids. © The Author 2017. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  9. Molecular analysis and MIRU-VNTR typing of Mycobacterium avium subsp. avium, 'hominissuis' and silvaticum strains of veterinary origin.

    Science.gov (United States)

    Rónai, Zsuzsanna; Csivincsik, Ágnes; Dán, Ádám; Gyuranecz, Miklós

    2016-06-01

    Besides Mycobacterium avium subsp. paratuberculosis (MAP), M. avium subsp. avium (MAA), M. avium subsp. silvaticum (MAS), and 'M. avium subsp. hominissuis' (MAH) are equally important members of M. avium complex, with worldwide distribution and zoonotic potential. Genotypic discrimination is a prerequisite to epidemiological studies which can facilitate disease prevention through revealing infection sources and transmission routes. The primary aim of this study was to identify the genetic diversity within 135 MAA, 62 MAS, and 84 MAH strains isolated from wild and domestic mammals, reptiles and birds. Strains were tested for the presence of large sequence polymorphism LSP(A)17 and were submitted to Mycobacterial interspersed repetitive units-variable-number tandem repeat (MIRU-VNTR) analysis at 8 loci, including MIRU1, 2, 3, and 4, VNTR25, 32, and 259, and MATR9. In 12 strains hsp65 sequence code type was also determined. LSP(A)17 was present only in 19.9% of the strains. All LSP(A)17 positive strains belonged to subspecies MAH. The discriminatory power of the MIRU-VNTR loci set used reached 0.9228. Altogether 54 different genotypes were detected. Within MAH, MAA, and MAS strains 33, 16, and 5 different genotypes were observed. The described genotypes were not restricted to geographic regions or host species, but proved to be subspecies specific. Our knowledge about MAS is limited due to isolation and identification difficulties. This is the first study including a large number of MAS field strains. Our results demonstrate the high diversity of MAH and MAA strains and the relative uniformity of MAS strains. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Strain- and Substrate-Dependent Redox Mediator and Electricity Production by Pseudomonas aeruginosa.

    Science.gov (United States)

    Bosire, Erick M; Blank, Lars M; Rosenbaum, Miriam A

    2016-08-15

    Pseudomonas aeruginosa is an important, thriving member of microbial communities of microbial bioelectrochemical systems (BES) through the production of versatile phenazine redox mediators. Pure culture experiments with a model strain revealed synergistic interactions of P. aeruginosa with fermenting microorganisms whereby the synergism was mediated through the shared fermentation product 2,3-butanediol. Our work here shows that the behavior and efficiency of P. aeruginosa in mediated current production is strongly dependent on the strain of P. aeruginosa We compared levels of phenazine production by the previously investigated model strain P. aeruginosa PA14, the alternative model strain P. aeruginosa PAO1, and the BES isolate Pseudomonas sp. strain KRP1 with glucose and the fermentation products 2,3-butanediol and ethanol as carbon substrates. We found significant differences in substrate-dependent phenazine production and resulting anodic current generation for the three strains, with the BES isolate KRP1 being overall the best current producer and showing the highest electrochemical activity with glucose as a substrate (19 μA cm(-2) with ∼150 μg ml(-1) phenazine carboxylic acid as a redox mediator). Surprisingly, P. aeruginosa PAO1 showed very low phenazine production and electrochemical activity under all tested conditions. Microbial fuel cells and other microbial bioelectrochemical systems hold great promise for environmental technologies such as wastewater treatment and bioremediation. While there is much emphasis on the development of materials and devices to realize such systems, the investigation and a deeper understanding of the underlying microbiology and ecology are lagging behind. Physiological investigations focus on microorganisms exhibiting direct electron transfer in pure culture systems. Meanwhile, mediated electron transfer with natural redox compounds produced by, for example, Pseudomonas aeruginosa might enable an entire microbial

  11. Genetic interaction between the ero1-1 and leu2 mutations in Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    López-Mirabal, H Reynaldo; Winther, Jakob R; Kielland-Brandt, Morten C

    2007-01-01

    of the ero1-1 mutation were carried out in a leu2 mutant. The ero1-1 leu2 strain does not grow in standard synthetic complete medium at 30 degrees C, a defect that can be remedied by increasing the L-leucine concentration in the medium or by transforming the ero1-1 leu2 strain with the LEU2 wild-type allele...

  12. Increased bactericidal activity of colistin on Pseudomonas aeruginosa biofilms in anaerobic conditions

    DEFF Research Database (Denmark)

    Kolpen, Mette; Appeldorff, Cecilie F.; Brandt, Sarah

    2016-01-01

    that production of OH˙may not contribute significantly to the bactericidal activity of colistin on P. aeruginosa biofilm. Thus, we investigated the effect of colistin treatment on biofilm of wild-type PAO1, a catalase-deficient mutant (katA) and a colistin-resistant CF isolate cultured in microtiter plates...

  13. Vaccination with an Attenuated Mutant of Ehrlichia chaffeensis Induces Pathogen-Specific CD4+ T Cell Immunity and Protection from Tick-Transmitted Wild-Type Challenge in the Canine Host.

    Directory of Open Access Journals (Sweden)

    Jodi L McGill

    Full Text Available Ehrlichia chaffeensis is a tick-borne rickettsial pathogen and the causative agent of human monocytic ehrlichiosis. Transmitted by the Amblyomma americanum tick, E. chaffeensis also causes disease in several other vertebrate species including white-tailed deer and dogs. We have recently described the generation of an attenuated mutant strain of E. chaffeensis, with a mutation in the Ech_0660 gene, which is able to confer protection from secondary, intravenous-administered, wild-type E. chaffeensis infection in dogs. Here, we extend our previous results, demonstrating that vaccination with the Ech_0660 mutant protects dogs from physiologic, tick-transmitted, secondary challenge with wild-type E. chaffeensis; and describing, for the first time, the cellular and humoral immune responses induced by Ech_0660 mutant vaccination and wild-type E. chaffeensis infection in the canine host. Both vaccination and infection induced a rise in E. chaffeensis-specific antibody titers and a significant Th1 response in peripheral blood as measured by E. chaffeensis antigen-dependent CD4+ T cell proliferation and IFNγ production. Further, we describe for the first time significant IL-17 production by peripheral blood leukocytes from both Ech_0660 mutant vaccinated animals and control animals infected with wild-type E. chaffeensis, suggesting a previously unrecognized role for IL-17 and Th17 cells in the immune response to rickettsial pathogens. Our results are a critical first step towards defining the role of the immune system in vaccine-induced protection from E. chaffeensis infection in an incidental host; and confirm the potential of the attenuated mutant clone, Ech_0660, to be used as a vaccine candidate for protection against tick-transmitted E. chaffeensis infection.

  14. Characterization of the Pseudomonas aeruginosa recA analog and its protein product: rec-102 is a mutant allele of the P. aeruginosa PAO recA gene

    Energy Technology Data Exchange (ETDEWEB)

    Kokjohn, T.A.; Miller, R.V.

    1987-04-01

    We cloned a 2.3-kilobase-pair fragment of the Pseudomonas aeruginosa PAO chromosome which is capable of complementing recA mutations of Escherichia coli. The recA-complementing activity was further localized to a 1.5-kilobase-pair PvuII-HindIII fragment. Southern blot analysis under conditions of high stringency indicated that DNA sequence homology is shared by the E. coli recA gene and the P. aeruginosa recA analog. The cloned recA analog was shown to restore resistance to methyl methanesulfonate, nitrofurantoin, and UV irradiation to E. coli recA mutants. Upon introduction of the cloned P. aeruginosa gene, these mutants regained recombination proficiency in HfrH-mediated conjugation and the ability to induce lambda prophages and SOS functions (din gene transcription) after exposure to DNA-damaging agents. Lambda prophage carrying a cI ind mutation was not inducible, suggesting that the mechanism of induction of these SOS functions by the P. aeruginosa RecA analog is similar to that by the activated E. coli RecA protein. The product of the recA analog was identified in minicells as a protein of approximately 47,000 daltons. Western blot analysis using anti-E. coli RecA antibody demonstrated that this protein is antigenically cross-reactive with the E. coli recA protein. The recA-containing fragment was cloned into the broad-host-range vector pCP13 and introduced into Rec- strains of P. aeruginosa containing the rec-102 allele. The plasmid was shown to restore recombination proficiency in FP5-mediated conjugations and to restore resistance to UV irradiation and methyl methanesulfonate to these Rec- mutants. It was shown that a wild-type allele of rec-102 is necessary for UV-mediated induction of D3 and F116 prophages. The cloned recA analog restored the UV inducibility of these prophages in rec-102 mutants.

  15. Characterization of the Pseudomonas aeruginosa recA analog and its protein product: rec-102 is a mutant allele of the P. aeruginosa PAO recA gene

    International Nuclear Information System (INIS)

    Kokjohn, T.A.; Miller, R.V.

    1987-01-01

    We cloned a 2.3-kilobase-pair fragment of the Pseudomonas aeruginosa PAO chromosome which is capable of complementing recA mutations of Escherichia coli. The recA-complementing activity was further localized to a 1.5-kilobase-pair PvuII-HindIII fragment. Southern blot analysis under conditions of high stringency indicated that DNA sequence homology is shared by the E. coli recA gene and the P. aeruginosa recA analog. The cloned recA analog was shown to restore resistance to methyl methanesulfonate, nitrofurantoin, and UV irradiation to E. coli recA mutants. Upon introduction of the cloned P. aeruginosa gene, these mutants regained recombination proficiency in HfrH-mediated conjugation and the ability to induce lambda prophages and SOS functions (din gene transcription) after exposure to DNA-damaging agents. Lambda prophage carrying a cI ind mutation was not inducible, suggesting that the mechanism of induction of these SOS functions by the P. aeruginosa RecA analog is similar to that by the activated E. coli RecA protein. The product of the recA analog was identified in minicells as a protein of approximately 47,000 daltons. Western blot analysis using anti-E. coli RecA antibody demonstrated that this protein is antigenically cross-reactive with the E. coli recA protein. The recA-containing fragment was cloned into the broad-host-range vector pCP13 and introduced into Rec- strains of P. aeruginosa containing the rec-102 allele. The plasmid was shown to restore recombination proficiency in FP5-mediated conjugations and to restore resistance to UV irradiation and methyl methanesulfonate to these Rec- mutants. It was shown that a wild-type allele of rec-102 is necessary for UV-mediated induction of D3 and F116 prophages. The cloned recA analog restored the UV inducibility of these prophages in rec-102 mutants

  16. Oral carcinogenesis is not achieved in different carcinogen-treated PAI-1 transgenic and wild-type mouse models.

    Science.gov (United States)

    Avgoustidis, Dimitris; Nisyrios, Themistoklis; Nkenke, Emeka; Lijnen, Roger; Ragos, Vassilis; Perrea, Despina; Donta, Ismini; Vaena, Apostolia; Yapijakis, Christos; Vairaktaris, Eleftherios

    2012-01-01

    In an effort to assess the role of plasminogen activator inhibitor-1 (PAI-1) in oral squamous cancer development and progression, two different carcinogen treatment protocols were conducted. Protocol I included mice from a PAI-1 transgenic (Tg) breed (n=56) and their wild-type (WT) counterparts (n=56), divided into one control group and two main experimental groups, treated with 7,12-dimethylbenz[a]anthracene (DMBA) for 8 and 16 weeks, respectively. Protocol II included the same number and types of animals and groups, which were similarly treated with 4-Nitroquinoline 1-oxide (4-NQO) in drinking water. Two drugs that affect plasma PAI-1 levels, enalapril and pravastatin, were administered to certain subgroups of animals in both protocols. None of the animals developed macroscopically-visible oral cancer lesions. Eleven animals under Protocol I and 52 animals under Protocol II died. Skin lesions were noted only in DMBA-treated animals (n=9). Almost all animals administered with 4-NQO developed alopecia and lost weight, while two of them developed stomach tumours, and one female mouse developed a large ovarian cyst. Transgenic mice may respond differently when used in well-established carcinogen models and oral carcinogenesis is hard to achieve in these rodents.

  17. Discriminatory Indices of Typing Methods for Epidemiologic Analysis of Contemporary Staphylococcus aureus Strains.

    Science.gov (United States)

    Rodriguez, Marcela; Hogan, Patrick G; Satola, Sarah W; Crispell, Emily; Wylie, Todd; Gao, Hongyu; Sodergren, Erica; Weinstock, George M; Burnham, Carey-Ann D; Fritz, Stephanie A

    2015-09-01

    Historically, a number of typing methods have been evaluated for Staphylococcus aureus strain characterization. The emergence of contemporary strains of community-associated S. aureus, and the ensuing epidemic with a predominant strain type (USA300), necessitates re-evaluation of the discriminatory power of these typing methods for discerning molecular epidemiology and transmission dynamics, essential to investigations of hospital and community outbreaks. We compared the discriminatory index of 5 typing methods for contemporary S. aureus strain characterization. Children presenting to St. Louis Children's Hospital and community pediatric practices in St. Louis, Missouri (MO), with community-associated S. aureus infections were enrolled. Repetitive sequence-based PCR (repPCR), pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST), staphylococcal protein A (spa), and staphylococcal cassette chromosome (SCC) mec typing were performed on 200 S. aureus isolates. The discriminatory index of each method was calculated using the standard formula for this metric, where a value of 1 is highly discriminatory and a value of 0 is not discriminatory. Overall, we identified 26 distinct strain types by repPCR, 17 strain types by PFGE, 30 strain types by MLST, 68 strain types by spa typing, and 5 strain types by SCCmec typing. RepPCR had the highest discriminatory index (D) of all methods (D = 0.88), followed by spa typing (D = 0.87), MLST (D = 0.84), PFGE (D = 0.76), and SCCmec typing (D = 0.60). The method with the highest D among MRSA isolates was repPCR (D = 0.64) followed by spa typing (D = 0.45) and MLST (D = 0.44). The method with the highest D among MSSA isolates was spa typing (D = 0.98), followed by MLST (D = 0.93), repPCR (D = 0.92), and PFGE (D = 0.89). Among isolates designated USA300 by PFGE, repPCR was most discriminatory, with 10 distinct strain types identified (D = 0.63). We identified 45

  18. Vaccine and Wild-Type Strains of Yellow Fever Virus Engage Distinct Entry Mechanisms and Differentially Stimulate Antiviral Immune Responses.

    Science.gov (United States)

    Fernandez-Garcia, Maria Dolores; Meertens, Laurent; Chazal, Maxime; Hafirassou, Mohamed Lamine; Dejarnac, Ophélie; Zamborlini, Alessia; Despres, Philippe; Sauvonnet, Nathalie; Arenzana-Seisdedos, Fernando; Jouvenet, Nolwenn; Amara, Ali

    2016-02-09

    The live attenuated yellow fever virus (YFV) vaccine 17D stands as a "gold standard" for a successful vaccine. 17D was developed empirically by passaging the wild-type Asibi strain in mouse and chicken embryo tissues. Despite its immense success, the molecular determinants for virulence attenuation and immunogenicity of the 17D vaccine are poorly understood. 17D evolved several mutations in its genome, most of which lie within the envelope (E) protein. Given the major role played by the YFV E protein during virus entry, it has been hypothesized that the residues that diverge between the Asibi and 17D E proteins may be key determinants of attenuation. In this study, we define the process of YFV entry into target cells and investigate its implication in the activation of the antiviral cytokine response. We found that Asibi infects host cells exclusively via the classical clathrin-mediated endocytosis, while 17D exploits a clathrin-independent pathway for infectious entry. We demonstrate that the mutations in the 17D E protein acquired during the attenuation process are sufficient to explain the differential entry of Asibi versus 17D. Interestingly, we show that 17D binds to and infects host cells more efficiently than Asibi, which culminates in increased delivery of viral RNA into the cytosol and robust activation of the cytokine-mediated antiviral response. Overall, our study reveals that 17D vaccine and Asibi enter target cells through distinct mechanisms and highlights a link between 17D attenuation, virus entry, and immune activation. The yellow fever virus (YFV) vaccine 17D is one of the safest and most effective live virus vaccines ever developed. The molecular determinants for virulence attenuation and immunogenicity of 17D are poorly understood. 17D was generated by serially passaging the virulent Asibi strain in vertebrate tissues. Here we examined the entry mechanisms engaged by YFV Asibi and the 17D vaccine. We found the two viruses use different entry

  19. Piper betle leaf extract affects the quorum sensing and hence virulence of Pseudomonas aeruginosa PAO1.

    Science.gov (United States)

    Datta, Siraj; Jana, Debanjan; Maity, Tilak Raj; Samanta, Aveek; Banerjee, Rajarshi

    2016-06-01

    Quorum sensing (QS) plays an important role in virulence of Pseudomonas aeruginosa, blocking of QS ability are viewed as viable antimicrobial chemotherapy and which may prove to be a safe anti-virulent drug. Bioactive components from Piper betle have been reported to possess antimicrobial ability. This study envisages on the anti-QS properties of ethanolic extract of P. betle leaf (PbLE) using P. aeruginosa PAO1 as a model organism. A marked reduction in swarming, swimming, and twitching ability of the bacteria is demonstrated in presence of PbLE. The biofilm and pyocyanin production also shows a marked reduction in presence of PbLE, though it does not affect the bacterial growth. Thus, the studies hint on the possible effect of the bioactive components of PbLE on reducing the virulent ability of the bacteria; identification of bioactive compounds should be investigated further.

  20. Construction of a recombinant Bacillus velezensis strain as an integrated control agent against plant diseases and insect pests.

    Science.gov (United States)

    Roh, Jong Yul; Liu, Qin; Choi, Jae Young; Wang, Yong; Shim, Hee Jin; Xu, Hong Guang; Choi, Gyung Ja; Kim, Jin-Cheol; Je, Yeon Ho

    2009-10-01

    To construct a new recombinant strain of Bacillus velezensis that has antifungal and insecticidal activity via the expression of the insecticidal Bacillus thuringiensis crystal protein, a B. thuringiensis expression vector (pHT1K-1Ac) was generated that contained the B. thuringiensis cry1Ac gene under the control of its endogenous promoter in a minimal E. coli-B. thuringiensis shuttle vector (pHT1K). This vector was introduced into a B. velezensis isolate that showed high antifungal activities against several plant diseases, including rice blast (Magnaporthe grisea), rice sheath blight (Rhizotonia solani), tomato gray mold (Botrytis cinerea), tomato late blight (Phytophthora infestans), and wheat leaf rust (Puccinia recondita), by electroporation. The recombinant B. velezensis strain was confirmed by PCR using cry1Ac-specific primers. Additionally, the recombinant strain produced a protein approximately 130 kDa in size and parasporal inclusion bodies similar to B. thuringiensis. The in vivo antifungal activity assay demonstrated that the activity of the recombinant B. velezensis strain was maintained at the same level as that of wild-type B. velezensis. Furthermore, it exhibited high insecticidal activity against a lepidopteran pest, Plutella xylostella, although its activity was lower than that of a recombinant B. thuringiensis strain, whereas wild-type B. velezensis strain did not show any insecticidal activity. These results suggest that this recombinant B. velezensis strain can be used to control harmful insect pests and fungal diseases simultaneously in one crop.

  1. Glucocorticoid-regulated and constitutive trafficking of proteolytically processed cell surface-associated glycoproteins in wild type and variant rat hepatoma cells

    International Nuclear Information System (INIS)

    Amacher, S.L.; Goodman, L.J.; Bravo, D.A.; Wong, K.Y.; Goldfine, I.D.; Hawley, D.M.; Firestone, G.L.

    1989-01-01

    Glucocorticoids regulate the trafficking of mouse mammary tumor virus (MMTV) glycoproteins to the cell surface in the rat hepatoma cell line M1.54, but not in the immunoselected sorting variant CR4. To compare the localization of MMTV glycoproteins to another proteolytically processed glycoprotein, both wild type M1.54 cells and variant CR4 cells were transfected with a human insulin receptor (hIR) expression vector, pRSVhIR. The production of cell surface hIR was monitored in dexamethasone-treated and -untreated wild type M1.54 and variant CR4 cells by indirect immunofluorescence, direct plasma membrane immunoprecipitation, and by [125I] insulin binding. In both wild type and variant rat hepatoma cells, hIR were localized at the cell surface in the presence or in the absence of 1 microM dexamethasone. In contrast, the glucocorticoid-regulated trafficking of cell surface MMTV glycoproteins occurred only in wild type M1.54 cells. We conclude that the hIR, which undergoes posttranslational processing reactions similar to MMTV glycoproteins, does not require glucocorticoids to be transported to the plasma membrane and is representative of a subset of cell surface glycoproteins whose trafficking is constitutive in rat hepatoma cells. Thus, MMTV glycoproteins and hIR provide specific cell surface markers to characterize the glucocorticoid-regulated and constitutive sorting pathways

  2. Brunenders: a partially attenuated historic poliovirus type I vaccine strain.

    Science.gov (United States)

    Sanders, Barbara P; Liu, Ying; Brandjes, Alies; van Hoek, Vladimir; de Los Rios Oakes, Isabel; Lewis, John; Wimmer, Eckard; Custers, Jerome H H V; Schuitemaker, Hanneke; Cello, Jeronimo; Edo-Matas, Diana

    2015-09-01

    Brunenders, a type I poliovirus (PV) strain, was developed in 1952 by J. F. Enders and colleagues through serial in vitro passaging of the parental Brunhilde strain, and was reported to display partial neuroattenuation in monkeys. This phenotype of attenuation encouraged two vaccine manufacturers to adopt Brunenders as the type I component for their inactivated poliovirus vaccines (IPVs) in the 1950s, although today no licensed IPV vaccine contains Brunenders. Here we confirmed, in a transgenic mouse model, the report of Enders on the reduced neurovirulence of Brunenders. Although dramatically neuroattenuated relative to WT PV strains, Brunenders remains more virulent than the attenuated oral vaccine strain, Sabin 1. Importantly, the neuroattenuation of Brunenders does not affect in vitro growth kinetics and in vitro antigenicity, which were similar to those of Mahoney, the conventional type I IPV vaccine strain. We showed, by full nucleotide sequencing, that Brunhilde and Brunenders differ at 31 nucleotides, eight of which lead to amino acid changes, all located in the capsid. Upon exchanging the Brunenders capsid sequence with that of the Mahoney capsid, WT neurovirulence was regained in vivo, suggesting a role for the capsid mutations in Brunenders attenuation. To date, as polio eradication draws closer, the switch to using attenuated strains for IPV is actively being pursued. Brunenders preceded this novel strategy as a partially attenuated IPV strain, accompanied by decades of successful use in the field. Providing data on the attenuation of Brunenders may be of value in the further construction of attenuated PV strains to support the grand pursuit of the global eradication of poliomyelitis.

  3. Chemical composition of essential oil from ripe fruit of Schinus terebinthifolius Raddi and evaluation of its activity against wild strains of hospital origin.

    Science.gov (United States)

    Cole, E R; dos Santos, R B; Lacerda Júnior, V; Martins, J D L; Greco, S J; Cunha Neto, A

    2014-01-01

    The essential oil (EO) composition of ripe fruit of S. terebinthifolius Raddi was analyzed by GC-MS. The oil extraction yielded 6.54 ± 1.06% (w/w). Seventeen compounds were identified, accounting for 91.15% of the total oil, where monoterpenes constituted the main chemical class (85.81%), followed by sesquiterpenes (5.34%). The major monoterpene identified was δ-3-carene (30.37%), followed by limonene (17.44%), α-phellandrene (12.60%) and α-pinene (12.59%). Trans-caryophyllene (1.77%) was the major sesquiterpene identified. The antibacterial activity of the essential oil was evaluated against wild strains of hospital origin (Escherichia coli, Pseudomonas sp., Klebsiella oxytoca, Corynebacterium sp., Staphylococcus aureus, Enterobacter sp., Enterobacter agglomerans, Bacillus sp., Nocardia sp. and Streptococcus group D). The essential oil of the ripe fruit of S. terebinthifolius Raddi has shown to be active against all tested wild strains, with minimum inhibitory concentration ranging from 3.55 μg/mL to 56.86 μg/mL. However, it has revealed some differences in susceptibility: the general, Gram-positive species showed greater sensitivity to the action of EO, which is probably due to the lower structural complexity of their cell walls.

  4. Changes in fatty acid content and composition between wild type and CsHMA3 overexpressing Camelina sativa under heavy-metal stress.

    Science.gov (United States)

    Park, Won; Feng, Yufeng; Kim, Hyojin; Suh, Mi Chung; Ahn, Sung-Ju

    2015-09-01

    Under heavy-metal stress, CsHMA3 overexpressing transgenic Camelina plants displayed not only a better quality, but also a higher quantity of unsaturated fatty acids in their seeds compared with wild type. Camelina sativa L. belongs to the Brassicaceae family and is frequently used as a natural vegetable oil source, as its seeds contain a high content of fatty acids. In this study, we observed that, when subjected to heavy metals (Cd, Co, Zn and Pb), the seeds of CsHMA3 (Heavy-Metal P1B-ATPase 3) transgenic lines retained their original golden yellow color and smooth outline, unlike wild-type seeds. Furthermore, we investigated the fatty acids content and composition of wild type and CsHMA3 transgenic lines after heavy metal treatments compared to the control. The results showed higher total fatty acid amounts in seeds of CsHMA3 transgenic lines compared with those in wild-type seeds under heavy-metal stresses. In addition, the compositions of unsaturated fatty acids-especially 18:1 (oleic acid), 18:2 (linoleic acid; only in case of Co treatment), 18:3 (linolenic acid) and 20:1 (eicosenoic acid)-in CsHMA3 overexpressing transgenic lines treated with heavy metals were higher than those of wild-type seeds under the same conditions. Furthermore, reactive oxygen species (ROS) contents in wild-type leaves and roots when treated with heavy metal were higher than in CsHMA3 overexpressing transgenic lines. These results indicate that overexpression of CsHMA3 affects fatty acid composition and content-factors that are responsible for the fuel properties of biodiesel-and can alleviate ROS accumulation caused by heavy-metal stresses in Camelina. Due to these factors, we propose that CsHMA3 transgenic Camelina can be used for phytoremediation of metal-contaminated soil as well as for oil production.

  5. Hepcidin regulation in wild-type and Hfe knockout mice in response to alcohol consumption: evidence for an alcohol-induced hypoxic response.

    Science.gov (United States)

    Heritage, Mandy L; Murphy, Therese L; Bridle, Kim R; Anderson, Gregory J; Crawford, Darrell H G; Fletcher, Linda M

    2009-08-01

    Expression of Hamp1, the gene encoding the iron regulatory peptide hepcidin, is inappropriately low in HFE-associated hereditary hemochromatosis and Hfe knockout mice (Hfe(-/-)). Since chronic alcohol consumption is also associated with disturbances in iron metabolism, we investigated the effects of alcohol consumption on hepcidin mRNA expression in Hfe(-/-) mice. Hfe(-/-) and C57BL/6 (wild-type) mice were pair-fed either an alcohol liquid diet or control diet for up to 8 weeks. The mRNA levels of hepcidin and ferroportin were measured at the mRNA level by RT-PCR and protein expression of hypoxia inducible factor-1 alpha (HIF-1alpha) was measured by western blot. Hamp1 mRNA expression was significantly decreased and duodenal ferroportin expression was increased in alcohol-fed wild-type mice at 8 weeks. Time course experiments showed that the decrease in hepcidin mRNA was not immediate, but was significant by 4 weeks. Consistent with the genetic defect, Hamp1 mRNA was decreased and duodenal ferroportin mRNA expression was increased in Hfe(-/-) mice fed on the control diet compared with wild-type animals and alcohol further exacerbated these effects. HIF-1alpha protein levels were elevated in alcohol-fed wild-type animals compared with controls. Alcohol may decrease Hamp1 gene expression independently of the HFE pathway possibly via alcohol-induced hypoxia.

  6. A novel wild-type Saccharomyces cerevisiae strain TSH1 in scaling-up of solid-state fermentation of ethanol from sweet sorghum stalks.

    Science.gov (United States)

    Du, Ran; Yan, Jianbin; Feng, Quanzhou; Li, Peipei; Zhang, Lei; Chang, Sandra; Li, Shizhong

    2014-01-01

    The rising demand for bioethanol, the most common alternative to petroleum-derived fuel used worldwide, has encouraged a feedstock shift to non-food crops to reduce the competition for resources between food and energy production. Sweet sorghum has become one of the most promising non-food energy crops because of its high output and strong adaptive ability. However, the means by which sweet sorghum stalks can be cost-effectively utilized for ethanol fermentation in large-scale industrial production and commercialization remains unclear. In this study, we identified a novel Saccharomyces cerevisiae strain, TSH1, from the soil in which sweet sorghum stalks were stored. This strain exhibited excellent ethanol fermentative capacity and ability to withstand stressful solid-state fermentation conditions. Furthermore, we gradually scaled up from a 500-mL flask to a 127-m3 rotary-drum fermenter and eventually constructed a 550-m3 rotary-drum fermentation system to establish an efficient industrial fermentation platform based on TSH1. The batch fermentations were completed in less than 20 hours, with up to 96 tons of crushed sweet sorghum stalks in the 550-m3 fermenter reaching 88% of relative theoretical ethanol yield (RTEY). These results collectively demonstrate that ethanol solid-state fermentation technology can be a highly efficient and low-cost solution for utilizing sweet sorghum, providing a feasible and economical means of developing non-food bioethanol.

  7. Trypanosoma cruzi strains isolated from human, vector, and animal reservoir in the same endemic region in Mexico and typed as T. cruzi I, discrete typing unit 1 exhibit considerable biological diversity

    Directory of Open Access Journals (Sweden)

    María del Carmen Sánchez-Guillén

    2006-09-01

    Full Text Available In this study, three strains of Trypanosoma cruzi were isolated at the same time and in the same endemic region in Mexico from a human patient with chronic chagasic cardiomyopathy (RyC-H; vector (Triatoma barberi (RyC-V; and rodent reservoir (Peromyscus peromyscus (RyC-R. The three strains were characterized by multilocus enzyme electrophoresis, random amplified polymorphic DNA, and by pathological profiles in experimental animals (biodemes. Based on the analysis of genetic markers the three parasite strains were typed as belonging to T. cruzi I major group, discrete typing unit 1. The pathological profile of RyC-H and RyC-V strains indicated medium virulence and low mortality and, accordingly, the strains should be considered as belonging to biodeme Type III. On the other hand, the parasites from RyC-R strain induced more severe inflammatory processes and high mortality (> 40% and were considered as belonging to biodeme Type II. The relationship between genotypes and biological characteristics in T. cruzi strains is still debated and not clearly understood. An expert committee recommended in 1999 that Biodeme Type III would correspond to T. cruzi I group, whereas Biodeme Type II, to T. cruzi II group. Our findings suggest that, at least for Mexican isolates, this correlation does not stand and that biological characteristics such as pathogenicity and virulence could be determined by factors different from those identified in the genotypic characterization

  8. Occurrence of Carbapenemase-Producing Enterobacteriaceae Isolates in the Wildlife: First Report of OXA-48 in Wild Boars in Algeria.

    Science.gov (United States)

    Bachiri, Taous; Bakour, Sofiane; Lalaoui, Rym; Belkebla, Nadia; Allouache, Meriem; Rolain, Jean Marc; Touati, Abdelaziz

    2018-04-01

    The aim of the present study was to screen for the presence of carbapenemase-producing Enterobacteriaceae (CPE) isolates from wild boars and Barbary macaques in Algeria. Fecal samples were collected from wild boars (n = 168) and Barbary macaques (n = 212), in Bejaia, Algeria, between September 2014 and April 2016. The isolates were identified and antimicrobial susceptibility was determined. Carbapenem resistance determinants were studied using PCR and sequencing, while clonal relatedness was performed using multilocus sequence typing (MLST). PCR was used to investigate certain virulence genes. Three CPE isolates from three different samples (1.8%) recovered from wild boars were identified as Escherichia coli (two isolates) and Klebsiella pneumoniae (one isolate). These isolates were resistant to amoxicillin, amoxicillin-clavulanate, tobramycin, ertapenem, and meropenem. The results of PCR and sequencing analysis showed that all three isolates produced the OXA-48 enzyme. The MLST showed that the two E. coli isolates were assigned to the same sequence type, ST635, and belonged to phylogroup A, whereas K. pneumoniae strain belonged to ST13. The K. pneumoniae strain was positive for multiple virulence factors, whereas no virulence determinants were found in E. coli isolates. This is the first report of OXA-48-producing Enterobacteriaceae in wild animals from Algeria and Africa.

  9. Dose selenomethionine have radio-protective effect on cell lines with wild type p53?

    International Nuclear Information System (INIS)

    Tsuji, K.; Hagihira, T.; Ohnishi, K.; Ohnishi, T.; Matsumoto, H.

    2003-01-01

    Full text: Selenium compounds are known to have cancer preventive effects. It is reported recently that selenium in the form of selenomethionine (SeMet) can protect cells with wild type p53 from UV-induced cell killing by activating the DNA repair mechanism of p53 tumor suppressor protein via redox factor Ref1 by reducing p53 cysteine residue 275 and 277. In contrast, SeMet has no protective effect on UV-induced cell killing in p53-null cells. If SeMet also has protective effect in cells with wild type p53 on cell killing by photon irradiation, SeMet can be used as normal tissue radio-protector. We examined the effect of SeMet on cell killing by X-ray irradiation in several cell lines with different p53 status at exponentially growing phase. Cell lines used in this experiment were as follows: H1299/neo; human lung cancer cell line of p53 null type tranfected with control vector with no p53, H1299/wp53; wild type p53 transfected counterpart. A172/neo; human glioblastoma cell line with wild type p53, A172/mp53-248; mp53-248 (248-mutant, ARG >TRP) transfected counterpart. SAS/neo; human tongue cancer cell line with wild type p53, and SAS/mp53-248; mp53-248 transfected counterpart. Cells were subcultured at monolayer in D-MEM containing 10% FBS. Survivals of the cells were determined by colony forming ability. Ten-MV linac X-ray was used to irradiate the cells. Exponentially growing cells were incubated with 20μM of SeMet for 15 hours before irradiation. After 24 hours exposure of SeMet, cells were incubated up to two weeks in growth medium for colony formation. Twenty-four hours exposure of 20μM of SeMet had no cytotoxicity on these cell lines. SeMet had no modification effect on cell killing by photon irradiation in H1299/neo, H1299/wp53, SAS/neo, SAS/mp53-248, and A172/mp53-248. On the other hand, SeMet sensitized A172/neo in radiation cell killing. The effects of p53 on interaction of SeMet and photon irradiation differ according to cell lines

  10. Improvement of selected strains through gamma irradiation for enhanced lipolytic potential

    International Nuclear Information System (INIS)

    Iftikhar, T.; Mubashir, N.; Hussain, Y.; Abbas, S.Q.; Ashraf, I.

    2010-01-01

    The purpose of the present investigation was to enhance the production of industrially important enzyme lipase by subjecting the wild lipase producing fungal strains i.e. Aspergillus niger, Rhizopus microsporus and Penicillium atrovenetum to various doses of gamma irradiation (20, 40, 60, 80, 100, 120, 140 and 160 Gy). The isolation and lipolytic activity of selected mutant derived strains is described in this paper. Among all the mutants tested, MBL-5 obtained at 140Gy of Aspergillus niger strain showed highest extracellular lipase activity (13.75 +- 0.15 U mL/sup -1/) while MBL-1 Rhizopus microsporus at the rate 20Gy showed the lowest activity i.e., 1.06 +- 0.11 U mL/sup -1/. A range of pH 3, 5, 7, 9 and 11 was used to check the lipolytic potential of various mutants along with their wild type. It was observed that MBL-5 (Aspergillus niger) and MBL-2 (Rhizopus microsporus) showed enhanced extracellular lipase activity at pH 11 while MBL-3 (Penicillium atrovenetum) showed the highest extracellular lipase activity 22.53 +- 0.21 U mL/sup -1/ at pH 9. It indicates a possible role for the MBL-2, MBL-3 and MBL-5 mutant strains in the detergent industry for the development of eco-friendly technologies. (author)

  11. Assessing the in vitro fitness of an oseltamivir-resistant seasonal A/H1N1 influenza strain using a mathematical model.

    Directory of Open Access Journals (Sweden)

    Benjamin P Holder

    2011-03-01

    Full Text Available In 2007, the A/Brisbane/59/2007 (H1N1 seasonal influenza virus strain acquired the oseltamivir-resistance mutation H275Y in its neuraminidase (NA gene. Although previous studies had demonstrated that this mutation impaired the replication capacity of the influenza virus in vitro and in vivo, the A/Brisbane/59/2007 H275Y oseltamivir-resistant mutant completely out-competed the wild-type (WT strain and was, in the 2008-2009 influenza season, the primary A/H1N1 circulating strain. Using a combination of plaque and viral yield assays, and a simple mathematical model, approximate values were extracted for two basic viral kinetics parameters of the in vitro infection. In the ST6GalI-MDCK cell line, the latent infection period (i.e., the time for a newly infected cell to start releasing virions was found to be 1-3 h for the WT strain and more than 7 h for the H275Y mutant. The infecting time (i.e., the time for a single infectious cell to cause the infection of another one was between 30 and 80 min for the WT, and less than 5 min for the H275Y mutant. Single-cycle viral yield experiments have provided qualitative confirmation of these findings. These results, though preliminary, suggest that the increased fitness success of the A/Brisbane/59/2007 H275Y mutant may be due to increased infectivity compensating for an impaired or delayed viral release, and are consistent with recent evidence for the mechanistic origins of fitness reduction and recovery in NA expression. The method applied here can reconcile seemingly contradictory results from the plaque and yield assays as two complementary views of replication kinetics, with both required to fully capture a strain's fitness.

  12. A novel wild-type Saccharomyces cerevisiae strain TSH1 in scaling-up of solid-state fermentation of ethanol from sweet sorghum stalks.

    Directory of Open Access Journals (Sweden)

    Ran Du

    Full Text Available The rising demand for bioethanol, the most common alternative to petroleum-derived fuel used worldwide, has encouraged a feedstock shift to non-food crops to reduce the competition for resources between food and energy production. Sweet sorghum has become one of the most promising non-food energy crops because of its high output and strong adaptive ability. However, the means by which sweet sorghum stalks can be cost-effectively utilized for ethanol fermentation in large-scale industrial production and commercialization remains unclear. In this study, we identified a novel Saccharomyces cerevisiae strain, TSH1, from the soil in which sweet sorghum stalks were stored. This strain exhibited excellent ethanol fermentative capacity and ability to withstand stressful solid-state fermentation conditions. Furthermore, we gradually scaled up from a 500-mL flask to a 127-m3 rotary-drum fermenter and eventually constructed a 550-m3 rotary-drum fermentation system to establish an efficient industrial fermentation platform based on TSH1. The batch fermentations were completed in less than 20 hours, with up to 96 tons of crushed sweet sorghum stalks in the 550-m3 fermenter reaching 88% of relative theoretical ethanol yield (RTEY. These results collectively demonstrate that ethanol solid-state fermentation technology can be a highly efficient and low-cost solution for utilizing sweet sorghum, providing a feasible and economical means of developing non-food bioethanol.

  13. Quantitative analysis of fatty-acid-based biofuels produced by wild-type and genetically engineered cyanobacteria by gas chromatography-mass spectrometry.

    Science.gov (United States)

    Guan, Wenna; Zhao, Hui; Lu, Xuefeng; Wang, Cong; Yang, Menglong; Bai, Fali

    2011-11-11

    Simple and rapid quantitative determination of fatty-acid-based biofuels is greatly important for the study of genetic engineering progress for biofuels production by microalgae. Ideal biofuels produced from biological systems should be chemically similar to petroleum, like fatty-acid-based molecules including free fatty acids, fatty acid methyl esters, fatty acid ethyl esters, fatty alcohols and fatty alkanes. This study founded a gas chromatography-mass spectrometry (GC-MS) method for simultaneous quantification of seven free fatty acids, nine fatty acid methyl esters, five fatty acid ethyl esters, five fatty alcohols and three fatty alkanes produced by wild-type Synechocystis PCC 6803 and its genetically engineered strain. Data obtained from GC-MS analyses were quantified using internal standard peak area comparisons. The linearity, limit of detection (LOD) and precision (RSD) of the method were evaluated. The results demonstrated that fatty-acid-based biofuels can be directly determined by GC-MS without derivation. Therefore, rapid and reliable quantitative analysis of fatty-acid-based biofuels produced by wild-type and genetically engineered cyanobacteria can be achieved using the GC-MS method founded in this work. Copyright © 2011 Elsevier B.V. All rights reserved.

  14. Segregating YKU80 and TLC1 alleles underlying natural variation in telomere properties in wild yeast.

    Directory of Open Access Journals (Sweden)

    Gianni Liti

    2009-09-01

    Full Text Available In yeast, as in humans, telomere length varies among individuals and is controlled by multiple loci. In a quest to define the extent of variation in telomere length, we screened 112 wild-type Saccharomyces sensu stricto isolates. We found extensive telomere length variation in S. paradoxus isolates. This phenotype correlated with their geographic origin: European strains were observed to have extremely short telomeres (400 bp. Insertions of a URA3 gene near telomeres allowed accurate analysis of individual telomere lengths and telomere position effect (TPE. Crossing the American and European strains resulted in F1 spores with a continuum of telomere lengths consistent with what would be predicted if many quantitative trait loci (QTLs were involved in length maintenance. Variation in TPE is similarly quantitative but only weakly correlated with telomere length. Genotyping F1 segregants indicated several QTLs associated with telomere length and silencing variation. These QTLs include likely candidate genes but also map to regions where there are no known genes involved in telomeric properties. We detected transgressive segregation for both phenotypes. We validated by reciprocal hemizygosity that YKU80 and TLC1 are telomere-length QTLs in the two S. paradoxus subpopulations. Furthermore, we propose that sequence divergence within the Ku heterodimer generates negative epistasis within one of the allelic combinations (American-YKU70 and European-YKU80 resulting in very short telomeres.

  15. Segregating YKU80 and TLC1 alleles underlying natural variation in telomere properties in wild yeast.

    Science.gov (United States)

    Liti, Gianni; Haricharan, Svasti; Cubillos, Francisco A; Tierney, Anna L; Sharp, Sarah; Bertuch, Alison A; Parts, Leopold; Bailes, Elizabeth; Louis, Edward J

    2009-09-01

    In yeast, as in humans, telomere length varies among individuals and is controlled by multiple loci. In a quest to define the extent of variation in telomere length, we screened 112 wild-type Saccharomyces sensu stricto isolates. We found extensive telomere length variation in S. paradoxus isolates. This phenotype correlated with their geographic origin: European strains were observed to have extremely short telomeres (400 bp). Insertions of a URA3 gene near telomeres allowed accurate analysis of individual telomere lengths and telomere position effect (TPE). Crossing the American and European strains resulted in F1 spores with a continuum of telomere lengths consistent with what would be predicted if many quantitative trait loci (QTLs) were involved in length maintenance. Variation in TPE is similarly quantitative but only weakly correlated with telomere length. Genotyping F1 segregants indicated several QTLs associated with telomere length and silencing variation. These QTLs include likely candidate genes but also map to regions where there are no known genes involved in telomeric properties. We detected transgressive segregation for both phenotypes. We validated by reciprocal hemizygosity that YKU80 and TLC1 are telomere-length QTLs in the two S. paradoxus subpopulations. Furthermore, we propose that sequence divergence within the Ku heterodimer generates negative epistasis within one of the allelic combinations (American-YKU70 and European-YKU80) resulting in very short telomeres.

  16. Wild-type male offspring of fmr-1+/- mothers exhibit characteristics of the fragile X phenotype.

    Science.gov (United States)

    Zupan, Bojana; Toth, Miklos

    2008-10-01

    Fragile X syndrome is an X-linked disorder caused by the inactivation of the FMR-1 gene with symptoms ranging from impaired cognitive functions to seizures, anxiety, sensory abnormalities, and hyperactivity. Males are more severely affected than heterozygote (H) females, who, as carriers, have a 50% chance of transmitting the mutated allele in each pregnancy. fmr-1 knockout (KO) mice reproduce fragile X symptoms, including hyperactivity, seizures, and abnormal sensory processing. In contrast to the expectation that wild-type (WT) males born to H (fmr-1(+/-)) mothers (H>WT) are behaviorally normal and indistinguishable from WT males born to WT mothers (WT>WT); here, we show that H>WT offspring are more active than WT>WT offspring and that their hyperactivity is similar to male KO mice born to H or KO (fmr-1(-/-)) mothers (H>KO/KO>KO). H>WT mice, however, do not exhibit seizures or abnormal sensory processing. Consistent with their hyperactivity, the effect of the D2 agonist quinpirole is reduced in H>WT as well as in H>KO and KO>KO mice compared to WT>WT offspring, suggesting a diminished feedback inhibition of dopamine release. Our data indicate that some aspects of hyperactivity and associated dopaminergic changes in 'fragile X' mice are a maternal fmr-1 genotype rather than an offspring fmr-1 genotype effect.

  17. Comparison of Tc-99m HM-PAO SPECT brain scan and x-ray CT in the detection of brain metastases

    International Nuclear Information System (INIS)

    Abdel-Dayem, H.M.; Sadek, S.; Sahwell, A.; Kubasek, H.; El-Sayed, M.; Ziada, G.; Mobarak, L.; Al-Huda, F.; Omar, Y.T.

    1986-01-01

    Tc-99m HM-PAO imaging was compared with x-ray CT in 14 patients with known or suspected brain metastases. Both studies were done within 3 days of each other. Static and single photon emission CT (SPECT) images were acquired after intravenous injection of 13 mCi of Tc-99m HM-PAO. All 14 patients underwent static and SPECT Tc-99m HM-PAO imaging and x-ray CT. Studies were positive in 7, 12, and 10 patients, respectively, by static, SPECT, and x-ray CT imaging, and negative in 7, 2, and 2. The number of lesions identified was 0 (static imaging), 32 (SPECT), and 26(x-ray CT). There were no ''suspicious'' studies by any modality. This study indicates that Tc-99m HM-PAO SPECT cerebral blood flow imaging is more sensitive than x-ray CT for detecting brain metastases, that biplane imaging is not sensitive and SPECT is essential, and that for Tc-99m HM-PAO SPECT brain imaging to regain its importance with respect to x-ray CT, acquisition time must be 10 minutes or less and determination of percentage brain uptake of the injected dose, and of regional distribution, is necessary

  18. Wt-ko_trxB1_Filtered bkg correc transf-norm

    OpenAIRE

    Serrano, L.M.; Molenaar, Douwe; Teusink, Bas; Vos, de, Willem; Smid, Eddy

    2007-01-01

    In this experiment we analyzed the impact of the disruption of trxB1in Lactobacillus plantarum at the transcriptome level. Furthermore we studied the effect of 3.5 mM peroxide effect on both Lactobacillus plantarum wild type (strain WCFS1) and a trxB1 mutant (strain NZ7608).

  19. Mid-aged and aged wild-type and progestin receptor knockout (PRKO) mice demonstrate rapid progesterone and 3alpha,5alpha-THP-facilitated lordosis.

    Science.gov (United States)

    Frye, C A; Sumida, K; Lydon, J P; O'Malley, B W; Pfaff, D W

    2006-05-01

    Progesterone (P) and its 5alpha-reduced metabolite, 3alpha-hydroxy-5alpha-pregnan-20-one (3alpha,5alpha-THP), facilitate sexual behavior of rodents via agonist-like actions at intracellular progestin receptors (PRs) and membrane GABA(A)/benzodiazepine receptor complexes (GBRs), respectively. Given that ovarian secretion of progestins declines with aging, whether or not senescent mice are responsive to progestins was of interest. Homozygous PR knockout (PRKO) or wild-type mice that were between 10-12 (mid-aged) or 20-24 (aged) months of age were administered P or 3alpha,5alpha-THP, and the effect on lordosis were examined. Effects of a progestin-priming regimen that enhances PR-mediated (experiment 1) or more rapid, PR-independent effects of progestins (experiments 2 and 3) on sexual behavior were examined. Levels of P, 3alpha,5alpha-THP, and muscimol binding were examined in tissues from aged mice (experiment 4). Wild-type, but not PRKO, mice were responsive when primed with 17beta-estradiol (E(2); 0.5 microg) and administered P (500 microg, subcutaneously). Mid-aged wild-type mice demonstrated greater increases in lordosis 6 h later compared to their pre-P, baseline test than did aged wild-type mice (experiment 1). Lordosis of younger and older wild-type, but not PRKO, mice was significantly increased within 5 min of intravenous (IV) administration of P (100 ng), compared with E(2)-priming alone (experiment 2). However, wild-type and PRKO mice demonstrated significant increases in lordosis 5 min after IV administration of 3alpha,5alpha-THP, an effect which was more pronounced in mid-aged than in aged animals (100 ng-experiment 3). In tissues from aged wild-type and PRKO mice, levels of P, 3alpha,5alpha-THP, and muscimol binding were increased by P administration (experiment 4). PR binding was lower in the cortex of PRKO than that of wild-type mice. Mid-aged and aged PRKO and wild-type mice demonstrated rapid P or 3alpha,5alpha-THP-facilitated lordosis that may be

  20. Typing of lymphogranuloma venereum Chlamydia trachomatis strains

    NARCIS (Netherlands)

    Christerson, Linus; de Vries, Henry J. C.; de Barbeyrac, Bertille; Gaydos, Charlotte A.; Henrich, Birgit; Hoffmann, Steen; Schachter, Julius; Thorvaldsen, Johannes; Vall-Mayans, Martí; Klint, Markus; Herrmann, Björn; Morré, Servaas A.

    2010-01-01

    We analyzed by multilocus sequence typing 77 lymphogranuloma venereum Chlamydia trachomatis strains from men who have sex with men in Europe and the United States. Specimens from an outbreak in 2003 in Europe were monoclonal. In contrast, several strains were in the United States in the 1980s,

  1. Strain-based HLA association analysis identified HLA-DRB1*09:01 associated with modern strain tuberculosis.

    Science.gov (United States)

    Toyo-Oka, L; Mahasirimongkol, S; Yanai, H; Mushiroda, T; Wattanapokayakit, S; Wichukchinda, N; Yamada, N; Smittipat, N; Juthayothin, T; Palittapongarnpim, P; Nedsuwan, S; Kantipong, P; Takahashi, A; Kubo, M; Sawanpanyalert, P; Tokunaga, K

    2017-09-01

    Tuberculosis (TB) occurs as a result of complex interactions between the host immune system and pathogen virulence factors. Human leukocyte antigen (HLA) class II molecules play an important role in the host immune system. However, no study has assessed the association between HLA class II genes and susceptibility to TB caused by specific strains. This study investigated the possible association of HLA class II genes with TB caused by modern and ancient Mycobacterium tuberculosis (MTB). The study included 682 patients with TB and 836 control subjects who were typed for HLA-DRB1 and HLA-DQB1 alleles. MTB strains were classified using a large sequence polymorphism typing method. Association analysis was performed using common HLA alleles and haplotypes in different MTB strains. HLA association analysis of patients infected with modern MTB strains showed significant association for HLA-DRB1*09:01 (odds ratio [OR] = 1.82; P-value = 9.88 × 10 -4 ) and HLA-DQB1*03:03 alleles (OR = 1.76; P-value = 1.31 × 10 -3 ) with susceptibility to TB. Haplotype analysis confirmed that these alleles were in strong linkage disequilibrium and did not exert an interactive effect. Thus, the results of this study showed an association between HLA class II genes and susceptibility to TB caused by modern MTB strains, suggesting the importance of strain-specific analysis to determine susceptibility genes associated with TB. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  2. Phosphorus-31 nuclear magnetic resonance studies of wild-type and glycolytic pathway mutants of Saccharomyces cerevisiae.

    Science.gov (United States)

    Navon, G; Shulman, R G; Yamane, T; Eccleshall, T R; Lam, K B; Baronofsky, J J; Marmur, J

    1979-10-16

    High-resolution phosphorus-31 nuclear magnetic resonance (31P NMR) spectra of wild-type and mutant strains of Saccharomyces cerevisiae were observed at a frequency of 145.7 MHz. Levels of various phosphorus metabolites were investigated upon addition of glucose under both aerobic and anaerobic conditions. Three mutant strains were isolated and their biochemical defects characterized: pfk lacked phosphofructokinase activity; pgi lacked phosphoglucose isomerase activity; and cif had no glucose catabolite repression of the fructose bisphosphatase activity. Each mutant strain was found to accumulate characteristic sugar phosphates when glucose was added to the cell suspension. In the case of the phosphofructokinase deficient mutant, the appearance of a pentose shunt metabolite was observed. 31P NMR peak assignments were made by a pH titration of the acid extract of the cells. Separate signals for terminal, penultimate, and central phosphorus atoms in intracellular polyphosphates allowed the estimation of their average molecular weight. Signals for glycero(3)phosphochline, glycero(3)phosphoserine, and glycero(3) phosphoethanolamine as well as three types of nucleotide diphosphate sugars could be observed. The intracellular pH in resting and anaerobic cells was in the range 6.5--6.8 and the level of adenosine 5'-triphosphate (ATP) low. Upon introduction of oxygen, the ATP level increased considerably and the intracellular pH reached a value of pH 7.2--7.3, irrespective of the external medium pH, indicating active proton transport in these cells. A new peak representing the inorganic phosphate of one of the cellular organelles, whose pH differed from the cytoplasmic pH, could be detected under appropriate conditions.

  3. Rearing in seawater mesocosms improves the spawning performance of growth hormone transgenic and wild-type coho salmon.

    Directory of Open Access Journals (Sweden)

    Rosalind A Leggatt

    Full Text Available Growth hormone (GH transgenes can significantly accelerate growth rates in fish and cause associated alterations to their physiology and behaviour. Concern exists regarding potential environmental risks of GH transgenic fish, should they enter natural ecosystems. In particular, whether they can reproduce and generate viable offspring under natural conditions is poorly understood. In previous studies, GH transgenic salmon grown under contained culture conditions had lower spawning behaviour and reproductive success relative to wild-type fish reared in nature. However, wild-type salmon cultured in equal conditions also had limited reproductive success. As such, whether decreased reproductive success of GH transgenic salmon is due to the action of the transgene or to secondary effects of culture (or a combination has not been fully ascertained. Hence, salmon were reared in large (350,000 L, semi-natural, seawater tanks (termed mesocosms designed to minimize effects of standard laboratory culture conditions, and the reproductive success of wild-type and GH transgenic coho salmon from mesocosms were compared with that of wild-type fish from nature. Mesocosm rearing partially restored spawning behaviour and success of wild-type fish relative to culture rearing, but remained lower overall than those reared in nature. GH transgenic salmon reared in the mesocosm had similar spawning behaviour and success as wild-type fish reared in the mesocosm when in full competition and without competition, but had lower success in male-only competition experiments. There was evidence of genotype×environmental interactions on spawning success, so that spawning success of transgenic fish, should they escape to natural systems in early life, cannot be predicted with low uncertainty. Under the present conditions, we found no evidence to support enhanced mating capabilities of GH transgenic coho salmon compared to wild-type salmon. However, it is clear that GH transgenic

  4. EXTRACTION AND PURIFICATION OF EXTRACELLULAR LACCASE FROM WILD, MUTANTS AND HYBRID STRAINS OF TWO WHITE-ROT FUNGUS AND ITS APPLICATIONS IN DECOLOURIZATION AND LIGNINOLYSIS

    Directory of Open Access Journals (Sweden)

    Olusola Majolagbe

    2012-12-01

    Full Text Available Extracellular laccases were extracted from a 5-day old submerge cultures of the wild, mutants and hybrid of Lentinus subnudus. Mutants were generated by exposure of the wild strain of L. subnudus to ultraviolet radiation (ג = 280 nm at specific time intervals while the hybrid was produced by cross-breeding L. subnudus with L. edodes. The crude enzyme was fractionated with 80% ammonium sulphate and further purified on DEAE column. The laccase has a molecular weight of about 45 KDa. Purification yield on DEAE column gave the highest purification yield of 23.25% in SWT and least in SHT (5.29%. Its potentials in decolourization of 2, 6-dichlorophenol-indophenol dye at different pH conditions were investigated. Five out of the six fungal strains tested gave significant (P<0.05 percentage decolourization (≥43.94% at pH 8. The fungus was further studied for their ability in degrading wheat and paddy straws. The solid substrate fermentation was inoculated with two pieces (0.6cm diameter mycelial agar blocks of each of the fungal strains, supplemented with 30mg/100g sucrose, 24mg/100g KNO3 and 60mg/100g CaCO3. The periodic reduction in weight of the solid substrate medium and enzymatic activity of laccase for each of the fungal strains was assessed. Therefore, the ability of the wild, mutants and hybrid of L subnudus strains to produce laccase enzyme shows their significant potential in textile industry, especially in decolourization of dye and bioconversion of lignocellulosic wastes.

  5. Effects of feedstock and co-culture of Lactobacillus fermentum and wild Saccharomyces cerevisiae strain during fuel ethanol fermentation by the industrial yeast strain PE-2.

    Science.gov (United States)

    Reis, Vanda R; Bassi, Ana Paula G; Cerri, Bianca C; Almeida, Amanda R; Carvalho, Isis G B; Bastos, Reinaldo G; Ceccato-Antonini, Sandra R

    2018-02-16

    Even though contamination by bacteria and wild yeasts are frequently observed during fuel ethanol fermentation, our knowledge regarding the effects of both contaminants together is very limited, especially considering that the must composition can vary from exclusively sugarcane juice to a mixture of molasses and juice, affecting the microbial development. Here we studied the effects of the feedstock (sugarcane juice and molasses) and the co-culture of Lactobacillus fermentum and a wild Saccharomyces cerevisiae strain (rough colony and pseudohyphae) in single and multiple-batch fermentation trials with an industrial strain of S. cerevisiae (PE-2) as starter yeast. The results indicate that in multiple-cycle batch system, the feedstock had a minor impact on the fermentation than in single-cycle batch system, however the rough yeast contamination was more harmful than the bacterial contamination in multiple-cycle batch fermentation. The inoculation of both contaminants did not potentiate the detrimental effect in any substrate. The residual sugar concentration in the fermented broth had a higher concentration of fructose than glucose for all fermentations, but in the presence of the rough yeast, the discrepancy between fructose and glucose concentrations were markedly higher, especially in molasses. The biggest problem associated with incomplete fermentation seemed to be the lower consumption rate of sugar and the reduced fructose preference of the rough yeast rather than the lower invertase activity. Lower ethanol production, acetate production and higher residual sugar concentration are characteristics strongly associated with the rough yeast strain and they were not potentiated with the inoculation of L. fermentum.

  6. Complete genome sequence of Mahella australiensis type strain (50-1 BONT)

    Energy Technology Data Exchange (ETDEWEB)

    Sikorski, Johannes [DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany; Teshima, Hazuki [Los Alamos National Laboratory (LANL); Nolan, Matt [U.S. Department of Energy, Joint Genome Institute; Lucas, Susan [U.S. Department of Energy, Joint Genome Institute; Hammon, Nancy [U.S. Department of Energy, Joint Genome Institute; Deshpande, Shweta [U.S. Department of Energy, Joint Genome Institute; Cheng, Jan-Fang [U.S. Department of Energy, Joint Genome Institute; Pitluck, Sam [U.S. Department of Energy, Joint Genome Institute; Liolios, Konstantinos [U.S. Department of Energy, Joint Genome Institute; Pagani, Ioanna [U.S. Department of Energy, Joint Genome Institute; Ivanova, N [U.S. Department of Energy, Joint Genome Institute; Huntemann, Marcel [U.S. Department of Energy, Joint Genome Institute; Mavromatis, K [U.S. Department of Energy, Joint Genome Institute; Ovchinnikova, Galina [U.S. Department of Energy, Joint Genome Institute; Pati, Amrita [U.S. Department of Energy, Joint Genome Institute; Tapia, Roxanne [Los Alamos National Laboratory (LANL); Han, Cliff [Los Alamos National Laboratory (LANL); Goodwin, Lynne A. [Los Alamos National Laboratory (LANL); Chen, Amy [U.S. Department of Energy, Joint Genome Institute; Palaniappan, Krishna [U.S. Department of Energy, Joint Genome Institute; Land, Miriam L [ORNL; Hauser, Loren John [ORNL; Ngatchou, Olivier Duplex [HZI - Helmholtz Centre for Infection Research, Braunschweig, Germany; Rohde, Manfred [HZI - Helmholtz Centre for Infection Research, Braunschweig, Germany; Pukall, Rudiger [DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany; Spring, Stefan [DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany; Abt, Birte [DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany; Goker, Markus [DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany; Detter, J. Chris [U.S. Department of Energy, Joint Genome Institute; Woyke, Tanja [U.S. Department of Energy, Joint Genome Institute; Bristow, James [U.S. Department of Energy, Joint Genome Institute; Markowitz, Victor [U.S. Department of Energy, Joint Genome Institute; Hugenholtz, Philip [U.S. Department of Energy, Joint Genome Institute; Eisen, Jonathan [U.S. Department of Energy, Joint Genome Institute; Kyrpides, Nikos C [U.S. Department of Energy, Joint Genome Institute; Klenk, Hans-Peter [DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany; Lapidus, Alla L. [U.S. Department of Energy, Joint Genome Institute

    2011-01-01

    Mahella australiensis Bonilla Salinas et al. 2004 is the type species of the genus Mahella, which belongs to the family Thermoanaerobacteraceae. The species is of interest because it differs from other known anaerobic spore-forming bacteria in its G+C content, and in certain phenotypic traits, such as carbon source utilization and relationship to temperature. Moreo- ver, it has been discussed that this species might be an indigenous member of petroleum and oil reservoirs. This is the first completed genome sequence of a member of the genus Mahella and the ninth completed type strain genome sequence from the family Thermoanaerobacte- raceae. The 3,135,972 bp long genome with its 2,974 protein-coding and 59 RNA genes is a part of the Genomic Encyclopedia of Bacteria and Archaea project.

  7. Engineering and preclinical evaluation of attenuated nontyphoidal Salmonella strains serving as live oral vaccines and as reagent strains.

    Science.gov (United States)

    Tennant, Sharon M; Wang, Jin-Yuan; Galen, James E; Simon, Raphael; Pasetti, Marcela F; Gat, Orit; Levine, Myron M

    2011-10-01

    While nontyphoidal Salmonella (NTS) has long been recognized as a cause of self-limited gastroenteritis, it is becoming increasingly evident that multiple-antibiotic-resistant strains are also emerging as important causes of invasive bacteremia and focal infections, resulting in hospitalizations and deaths. We have constructed attenuated Salmonella enterica serovar Typhimurium and Salmonella enterica serovar Enteritidis strains that can serve as live oral vaccines and as "reagent strains" for subunit vaccine production in a safe and economical manner. Prototype attenuated vaccine strains CVD 1921 and CVD 1941, derived from the invasive wild-type strains S. Typhimurium I77 and S. Enteritidis R11, respectively, were constructed by deleting guaBA, encoding guanine biosynthesis, and clpP, encoding a master protease regulator. The clpP mutation resulted in a hyperflagellation phenotype. An additional deletion in fliD yielded reagent strains CVD 1923 and CVD 1943, respectively, which export flagellin monomers. Oral 50% lethal dose (LD₅₀) analyses showed that the NTS vaccine strains were all highly attenuated in mice. Oral immunization with CVD 1921 or CVD 1923 protected mice against lethal challenge with wild-type S. Typhimurium I77. Immunization with CVD 1941 but not CVD 1943 protected mice against lethal infection with S. Enteritidis R11. Immune responses induced by these strains included high levels of serum IgG anti-lipopolysaccharide (LPS) and anti-flagellum antibodies, with titers increasing progressively during the immunization schedule. Since S. Typhimurium and S. Enteritidis are the most common NTS serovars associated with invasive disease, these findings can pave the way for development of a highly effective, broad-spectrum vaccine against invasive NTS.

  8. A Herpes Simplex Virus Type 1 Mutant Expressing a Baculovirus Inhibitor of Apoptosis Gene in Place of Latency-Associated Transcript Has a Wild-Type Reactivation Phenotype in the Mouse

    Science.gov (United States)

    Jin, Ling; Perng, Guey-Chuen; Mott, Kevin R.; Osorio, Nelson; Naito, Julia; Brick, David J.; Carpenter, Dale; Jones, Clinton; Wechsler, Steven L.

    2005-01-01

    The latency-associated transcript (LAT) is essential for the wild-type herpes simplex virus type 1 (HSV-1) high-reactivation phenotype since LAT− mutants have a low-reactivation phenotype. We previously reported that LAT can decrease apoptosis and proposed that this activity is involved in LAT's ability to enhance the HSV-1 reactivation phenotype. The first 20% of the primary 8.3-kb LAT transcript is sufficient for enhancing the reactivation phenotype and for decreasing apoptosis, supporting this proposal. For this study, we constructed an HSV-1 LAT− mutant that expresses the baculovirus antiapoptosis gene product cpIAP under control of the LAT promoter and in place of the LAT region mentioned above. Mice were ocularly infected with this mutant, designated dLAT-cpIAP, and the reactivation phenotype was determined using the trigeminal ganglion explant model. dLAT-cpIAP had a reactivation phenotype similar to that of wild-type virus and significantly higher than that of (i) the LAT− mutant dLAT2903; (ii) dLAT1.5, a control virus containing the same LAT deletion as dLAT-cpIAP, but with no insertion of foreign DNA, thereby controlling for potential readthrough transcription past the cpIAP insert; and (iii) dLAT-EGFP, a control virus identical to dLAT-cpIAP except that it contained the enhanced green fluorescent protein open reading frame (ORF) in place of the cpIAP ORF, thereby controlling for expression of a random foreign gene instead of the cpIAP gene. These results show that an antiapoptosis gene with no sequence similarity to LAT can efficiently substitute for the LAT function involved in enhancing the in vitro-induced HSV-1 reactivation phenotype in the mouse. PMID:16160155

  9. Characterization of a Wild, Novel Nisin A-Producing Lactococcus Strain with an L. lactis subsp. cremoris Genotype and an L. lactis subsp. lactis Phenotype, Isolated from Greek Raw Milk

    Science.gov (United States)

    Parapouli, Maria; Delbès-Paus, Céline; Kakouri, Athanasia; Koukkou, Anna-Irini; Montel, Marie-Christine

    2013-01-01

    Several molecular taxonomic studies have revealed that many natural (wild) Lactococcus lactis strains of dairy origin which are phenotypically representative of the L. lactis subspecies lactis cluster genotypically within subspecies cremoris and vice versa. Recently, we isolated two wild nisin-producing (Nis+) L. lactis strains, M78 and M104, of the lactis phenotype from Greek raw milk (J. Samelis, A. Lianou, A. Kakouri, C. Delbès, I. Rogelj, B. B. Matijašic, and M. C. Montel, J. Food Prot. 72:783–790, 2009); strain M78 possess a novel nisin A sequence (GenBank accession number HM219853). In this study, the actual subspecies identity of M78 and M104 isolates was elucidated, using 16S rRNA and acmA (encoding lactococcal N-acetylmuramidase) gene and histidine biosynthesis operon polymorphisms and 16S rRNA and ldh (encoding lactate dehydrogenase) gene phylogenies. Except the acmA gene analysis, molecular tools revealed that isolates M78 and M104 clustered with strains of the cremoris genotype, including the LMG 6897T strain, while they were distant from strains of the lactis genotype, including the LMG 6890T strain. The two wild isolates had identical repetitive sequence-based PCR (rep-PCR), randomly amplified polymorphic DNA (RAPD), plasmid, and whole-cell protein profiles and shared high 16S rRNA (99.9%) and ldh (100%) gene sequence homologies. In contrast, they exhibited identical sugar fermentation and enzymatic patterns which were similar to those of the subspecies lactis LMG 6890T strain. To our knowledge, this is the first complete identification report on a wild L. lactis subsp. cremoris genotype of the lactis phenotype which is capable of nisin A production and, thus, has strong potential for use as a novel dairy starter and/or protective culture. PMID:23542625

  10. Chemical composition of essential oil from ripe fruit of Schinus terebinthifolius Raddi and evaluation of its activity against wild strains of hospital origin

    Directory of Open Access Journals (Sweden)

    E.R. Cole

    2014-09-01

    Full Text Available The essential oil (EO composition of ripe fruit of S. terebinthifolius Raddi was analyzed by GC-MS. The oil extraction yielded 6.54 ± 1.06% (w/w. Seventeen compounds were identified, accounting for 91.15% of the total oil, where monoterpenes constituted the main chemical class (85.81%, followed by sesquiterpenes (5.34%. The major monoterpene identified was δ-3-carene (30.37%, followed by limonene (17.44%, α-phellandrene (12.60% and α-pinene (12.59%. Trans-caryophyllene (1.77% was the major sesquiterpene identified. The antibacterial activity of the essential oil was evaluated against wild strains of hospital origin (Escherichia coli, Pseudomonas sp., Klebsiella oxytoca, Corynebacterium sp., Staphylococcus aureus, Enterobacter sp., Enterobacter agglomerans, Bacillus sp., Nocardia sp. and Streptococcus group D. The essential oil of the ripe fruit of S. terebinthifolius Raddi has shown to be active against all tested wild strains, with minimum inhibitory concentration ranging from 3.55 μg/mL to 56.86 μg/mL. However, it has revealed some differences in susceptibility: the general, Gram-positive species showed greater sensitivity to the action of EO, which is probably due to the lower structural complexity of their cell walls.

  11. Oxygen effect and influence of the anoxic radiosensitizing agent TAN on the induction of λ-prophage in polA and wild type E.coli strains after gamma irradiation

    International Nuclear Information System (INIS)

    Bonev, M.N.; Sivriev, I.K.; Kolev, S.D.

    1998-01-01

    The modification effect of both oxygen and radiosensitizing agent TAN on the λ-prophage induction in polA mutant and wild type E.coli cells after γ-irradiation was studied. The oxygen and TAN enhancement ratio concerning the cell sensitivity is more significant in polA mutant cells as compared to that in the wild type ones. The same behaviour has been observed for the oxygen and TAN enhancement ratio for the λ-prophage induction. The TAN effect on the survival and on the λ-induction was smaller than the oxygen effect. The bigger efficiency of oxygen and DNA-radicals are more difficult to repair than those created by an interaction of TAN and DNA-radicals

  12. Transcriptional regulatory program in wild-type and retinoblastoma gene-deficient mouse embryonic fibroblasts during adipocyte differentiation

    DEFF Research Database (Denmark)

    Hakim-Weber, Robab; Krogsdam, Anne-M; Jørgensen, Claus

    2011-01-01

    Although many molecular regulators of adipogenesis have been identified a comprehensive catalogue of components is still missing. Recent studies showed that the retinoblastoma protein (pRb) was expressed in the cell cycle and late cellular differentiation phase during adipogenesis. To investigate...... this dual role of pRb in the early and late stages of adipogenesis we used microarrays to perform a comprehensive systems-level analysis of the common transcriptional program of the classic 3T3-L1 preadipocyte cell line, wild-type mouse embryonic fibroblasts (MEFs), and retinoblastoma gene-deficient MEFs...... of experimental data and computational analyses pinpointed a feedback-loop between Pparg and Foxo1.To analyze the effects of the retinoblastoma protein at the transcriptional level we chose a perturbated system (Rb-/- MEFs) for comparison to the transcriptional program of wild-type MEFs. Gene ontology analysis...

  13. GABA metabolism pathway genes, UGA1 and GAD1, regulate replicative lifespan in Saccharomycescerevisiae

    Energy Technology Data Exchange (ETDEWEB)

    Kamei, Yuka; Tamura, Takayuki [Department of Bioscience, Faculty of Bioscience, Nagahama Institute of Bio-Science and Technology, 1266 Tamura, Nagahama, Shiga 526-0829 (Japan); Yoshida, Ryo [Department of Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871 (Japan); Ohta, Shinji [Department of Bioscience, Faculty of Bioscience, Nagahama Institute of Bio-Science and Technology, 1266 Tamura, Nagahama, Shiga 526-0829 (Japan); Fukusaki, Eiichiro [Department of Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871 (Japan); Mukai, Yukio, E-mail: y_mukai@nagahama-i-bio.ac.jp [Department of Bioscience, Faculty of Bioscience, Nagahama Institute of Bio-Science and Technology, 1266 Tamura, Nagahama, Shiga 526-0829 (Japan)

    2011-04-01

    Highlights: {yields}We demonstrate that two genes in the yeast GABA metabolism pathway affect aging. {yields} Deletion of the UGA1 or GAD1 genes extends replicative lifespan. {yields} Addition of GABA to wild-type cultures has no effect on lifespan. {yields} Intracellular GABA levels do not differ in longevity mutants and wild-type cells. {yields} Levels of tricarboxylic acid cycle intermediates positively correlate with lifespan. -- Abstract: Many of the genes involved in aging have been identified in organisms ranging from yeast to human. Our previous study showed that deletion of the UGA3 gene-which encodes a zinc-finger transcription factor necessary for {gamma}-aminobutyric acid (GABA)-dependent induction of the UGA1 (GABA aminotransferase), UGA2 (succinate semialdehyde dehydrogenase), and UGA4 (GABA permease) genes-extends replicative lifespan in the budding yeast Saccharomycescerevisiae. Here, we found that deletion of UGA1 lengthened the lifespan, as did deletion of UGA3; in contrast, strains with UGA2 or UGA4 deletions exhibited no lifespan extension. The {Delta}uga1 strain cannot deaminate GABA to succinate semialdehyde. Deletion of GAD1, which encodes the glutamate decarboxylase that converts glutamate into GABA, also increased lifespan. Therefore, two genes in the GABA metabolism pathway, UGA1 and GAD1, were identified as aging genes. Unexpectedly, intracellular GABA levels in mutant cells (except for {Delta}uga2 cells) did not differ from those in wild-type cells. Addition of GABA to culture media, which induces transcription of the UGA structural genes, had no effect on replicative lifespan of wild-type cells. Multivariate analysis of {sup 1}H nuclear magnetic resonance spectra for the whole-cell metabolite levels demonstrated a separation between long-lived and normal-lived strains. Gas chromatography-mass spectrometry analysis of identified metabolites showed that levels of tricarboxylic acid cycle intermediates positively correlated with lifespan

  14. GABA metabolism pathway genes, UGA1 and GAD1, regulate replicative lifespan in Saccharomycescerevisiae

    International Nuclear Information System (INIS)

    Kamei, Yuka; Tamura, Takayuki; Yoshida, Ryo; Ohta, Shinji; Fukusaki, Eiichiro; Mukai, Yukio

    2011-01-01

    Highlights: →We demonstrate that two genes in the yeast GABA metabolism pathway affect aging. → Deletion of the UGA1 or GAD1 genes extends replicative lifespan. → Addition of GABA to wild-type cultures has no effect on lifespan. → Intracellular GABA levels do not differ in longevity mutants and wild-type cells. → Levels of tricarboxylic acid cycle intermediates positively correlate with lifespan. -- Abstract: Many of the genes involved in aging have been identified in organisms ranging from yeast to human. Our previous study showed that deletion of the UGA3 gene-which encodes a zinc-finger transcription factor necessary for γ-aminobutyric acid (GABA)-dependent induction of the UGA1 (GABA aminotransferase), UGA2 (succinate semialdehyde dehydrogenase), and UGA4 (GABA permease) genes-extends replicative lifespan in the budding yeast Saccharomycescerevisiae. Here, we found that deletion of UGA1 lengthened the lifespan, as did deletion of UGA3; in contrast, strains with UGA2 or UGA4 deletions exhibited no lifespan extension. The Δuga1 strain cannot deaminate GABA to succinate semialdehyde. Deletion of GAD1, which encodes the glutamate decarboxylase that converts glutamate into GABA, also increased lifespan. Therefore, two genes in the GABA metabolism pathway, UGA1 and GAD1, were identified as aging genes. Unexpectedly, intracellular GABA levels in mutant cells (except for Δuga2 cells) did not differ from those in wild-type cells. Addition of GABA to culture media, which induces transcription of the UGA structural genes, had no effect on replicative lifespan of wild-type cells. Multivariate analysis of 1 H nuclear magnetic resonance spectra for the whole-cell metabolite levels demonstrated a separation between long-lived and normal-lived strains. Gas chromatography-mass spectrometry analysis of identified metabolites showed that levels of tricarboxylic acid cycle intermediates positively correlated with lifespan extension. These results strongly suggest

  15. Parallel screening of wild-type and drug-resistant targets for anti-resistance neuraminidase inhibitors.

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    Kai-Cheng Hsu

    Full Text Available Infection with influenza virus is a major public health problem, causing serious illness and death each year. Emergence of drug-resistant influenza virus strains limits the effectiveness of drug treatment. Importantly, a dual H275Y/I223R mutation detected in the pandemic influenza A 2009 virus strain results in multidrug resistance to current neuraminidase (NA drugs. Therefore, discovery of new agents for treating multiple drug-resistant (MDR influenza virus infections is important. Here, we propose a parallel screening strategy that simultaneously screens wild-type (WT and MDR NAs, and identifies inhibitors matching the subsite characteristics of both NA-binding sites. These may maintain their potency when drug-resistant mutations arise. Initially, we analyzed the subsite of the dual H275Y/I223R NA mutant. Analysis of the site-moiety maps of NA protein structures show that the mutant subsite has a relatively small volume and is highly polar compared with the WT subsite. Moreover, the mutant subsite has a high preference for forming hydrogen-bonding interactions with polar moieties. These changes may drive multidrug resistance. Using this strategy, we identified a new inhibitor, Remazol Brilliant Blue R (RB19, an anthraquinone dye, which inhibited WT NA and MDR NA with IC(50 values of 3.4 and 4.5 µM, respectively. RB19 comprises a rigid core scaffold and a flexible chain with a large polar moiety. The former interacts with highly conserved residues, decreasing the probability of resistance. The latter forms van der Waals contacts with the WT subsite and yields hydrogen bonds with the mutant subsite by switching the orientation of its flexible side chain. Both scaffolds of RB19 are good starting points for lead optimization. The results reveal a parallel screening strategy for identifying resistance mechanisms and discovering anti-resistance neuraminidase inhibitors. We believe that this strategy may be applied to other diseases with high

  16. Clinical applications of brain perfusion imaging with 99mTc-HM-PAO

    International Nuclear Information System (INIS)

    Lin Xiangtong

    1989-01-01

    200 patients with central nervous system diseases were studied with 99m Tc-HM-PAO and SPECT, including Parkinson's disease (PD) 47, Vascular headache 69, CVD 34, Epilepsy 26, Head truma 10, Brain tumor 5 and other 9 cases. Part of them have been compared with the results of MRI, X-CT and EEG. The positivity of SPECT in PD is 61.7% with decrease perfusion in local area of cerebram and basal ganglia and only 4 cases had lower perfusion in cerebellum; in headache is 46.4%, showing variable perfusion patterns; in CVD is 79.4% with decrease perfusion, luxury perfusion and the phenomenon of 'diaschsis'. In epilepsy, the abnormal foci mostly localize in temporal lobe and have close relation to the results of EEG. In brain tumor it also denotes decreased uptake of tracer. The clinicl singnificance of brain perfusion imaging with 99m Tc-HM-PAO was discussed

  17. Rapid identification of drug-type strains in Cannabis sativa using loop-mediated isothermal amplification assay.

    Science.gov (United States)

    Kitamura, Masashi; Aragane, Masako; Nakamura, Kou; Watanabe, Kazuhito; Sasaki, Yohei

    2017-01-01

    In Cannabis sativa L., tetrahydrocannabinol (THC) is the primary psychoactive compound and exists as the carboxylated form, tetrahydrocannabinolic acid (THCA). C. sativa is divided into two strains based on THCA content-THCA-rich (drug-type) strains and THCA-poor (fiber-type) strains. Both strains are prohibited by law in many countries including Japan, whereas the drug-type strains are regulated in Canada and some European countries. As the two strains cannot be discriminated by morphological analysis, a simple method for identifying the drug-type strains is required for quality control in legal cultivation and forensic investigation. We have developed a novel loop-mediated isothermal amplification (LAMP) assay for identifying the drug-type strains of C. sativa. We designed two selective LAMP primer sets for on-site or laboratory use, which target the drug-type THCA synthase gene. The LAMP assay was accomplished within approximately 40 min. The assay showed high specificity for the drug-type strains and its sensitivity was the same as or higher than that of conventional polymerase chain reaction. We also showed the effectiveness of melting curve analysis that was conducted after the LAMP assay. The melting temperature values of the drug-type strains corresponded to those of the cloned drug-type THCA synthase gene, and were clearly different from those of the cloned fiber-type THCA synthase gene. Moreover, the LAMP assay with simple sample preparation could be accomplished within 1 h from sample treatment to identification without the need for special devices or techniques. Our rapid, sensitive, specific, and simple assay is expected to be applicable to laboratory and on-site detection.

  18. Biological characterization of bovine herpesvirus 1 recombinants possessing the vaccine glycoprotein E negative phenotype.

    Science.gov (United States)

    Muylkens, Benoît; Meurens, François; Schynts, Frédéric; de Fays, Katalin; Pourchet, Aldo; Thiry, Julien; Vanderplasschen, Alain; Antoine, Nadine; Thiry, Etienne

    2006-03-31

    Intramolecular recombination is a frequent event during the replication cycle of bovine herpesvirus 1 (BoHV-1). Recombinant viruses frequently arise and survive in cattle after concomitant nasal infections with two BoHV-1 mutants. The consequences of this process, related to herpesvirus evolution, have to be assessed in the context of large use of live marker vaccines based on glycoprotein E (gE) gene deletion. In natural conditions, double nasal infections by vaccine and wild-type strains are likely to occur. This situation might generate virulent recombinant viruses inducing a serological response indistinguishable from the vaccine one. This question was addressed by generating in vitro BoHV-1 recombinants deleted in the gE gene from seven wild-type BoHV-1 strains and one mutant strain deleted in the genes encoding gC and gE. In vitro growth properties were assessed by virus production, one step growth kinetics and plaque size assay. Heterogeneity in the biological properties was shown among the investigated recombinant viruses. The results demonstrated that some recombinants, in spite of their gE minus phenotype, have biological characteristics close to wild-type BoHV-1.

  19. STUDY DATA OF KRAS- AND RAS-UNMUTATED (WILD TYPE OF COLORECTAL CANCER

    Directory of Open Access Journals (Sweden)

    V. A. Gorbunova

    2015-01-01

    Full Text Available  Analysis of latest trials, comparing treatment schemes including chemotherapy with anti-EGFR monoclonal antibodies or bevacizumab is presented in this article. The data in these trials is inconsistent, but detailed analysis of FIRE-3 trial allows to distinguish a wild-type RAS patient group that benefits most from chemotherapy with cetuximab or panitumumab as 1st line metastatic colorectal cancer treatment. A final analysis of this patient group in CALGB/SWOG 80 405 trial is pending. The RAS analysis is pivotal for choice of 1st line chemotherapy.

  20. Fusarium spp. Associated with Field-Grown Grain of Near-Isogenic Low Lignin and Wild-Type Sorghum

    Science.gov (United States)

    Fusarium spp. associated with field-grown grain of near-isogenic low lignin and wild-type sorghum. Deanna Funnell-Harris and Jeff Pedersen, USDA-ARS, Lincoln, NE Previous studies indicated that low lignin brown midrib (bmr) sorghum may be more resistant to Fusarium spp. than wild-type and that phen...

  1. Transplacental and oral transmission of wild-type bluetongue virus serotype 8 in cattle after experimental infection

    NARCIS (Netherlands)

    Backx, A.; Heutink, C.G.; Rooij, van E.M.A.; Rijn, van P.A.

    2009-01-01

    Potential vertical transmission of wild-type bluetongue virus serotype 8 (BTV-8) in cattle was explored in this experiment. We demonstrated transplacental transmission of wild-type BTV-8 in one calf and oral infection with BTV-8 in another calf. Following the experimental BTV-8 infection of seven

  2. Neutropenia restores virulence to an attenuated Cu,Zn superoxide dismutase-deficient Haemophilus ducreyi strain in the swine model of chancroid.

    Science.gov (United States)

    San Mateo, L R; Toffer, K L; Orndorff, P E; Kawula, T H

    1999-10-01

    Haemophilus ducreyi causes chancroid, a sexually transmitted cutaneous genital ulcer disease associated with increased heterosexual transmission of human immunodeficiency virus. H. ducreyi expresses a periplasmic copper-zinc superoxide dismutase (Cu, Zn SOD) that protects the bacterium from killing by exogenous superoxide in vitro. We hypothesized that the Cu,Zn SOD would protect H. ducreyi from immune cell killing, enhance survival, and affect ulcer development in vivo. In order to test this hypothesis and study the role of the Cu,Zn SOD in H. ducreyi pathogenesis, we compared a Cu,Zn SOD-deficient H. ducreyi strain to its isogenic wild-type parent with respect to survival and ulcer development in immunocompetent and immunosuppressed pigs. The Cu,Zn SOD-deficient strain was recovered from significantly fewer inoculated sites and in significantly lower numbers than the wild-type parent strain or a merodiploid (sodC+ sodC) strain after infection of immunocompetent pigs. In contrast, survival of the wild-type and Cu,Zn SOD-deficient strains was not significantly different in pigs that were rendered neutropenic by treatment with cyclophosphamide. Ulcer severity in pigs was not significantly different between sites inoculated with wild type and sites inoculated with Cu,Zn SOD-deficient H. ducreyi. Our data suggest that the periplasmic Cu,Zn SOD is an important virulence determinant in H. ducreyi, protecting the bacterium from host immune cell killing and contributing to survival and persistence in the host.

  3. SPET with sup 99m Tc-HM PAO in the study of classic migraine. La SPET con sup 99m Tc-HM PAO nello studio dell'emicrania classica

    Energy Technology Data Exchange (ETDEWEB)

    Stiglich, F; Bonomo, F; Barbonetti, C; Di Lorenzo, I; Bottinelli, G [Ospedale Civile, Sondrio (Italy). Div. di Medicina Nucleare e Radioterapia; Tomaiolo, S [Ospedale Civile, Sondrio (Italy). Div. di Neurologia; Campani, R; Bottinelli, O [Pavia Univ. (Italy). Ist. di Radiologia

    1991-01-01

    Five patients presenting with migraine attacks underwent Electroencephalography (EEC), Computed Tomography (CT) and Single Photon Emission Tomography (SPET) with {sup 99m}Tc-HM PAO. EEG qand SPET were subsequently repeated in the intercritical period. We observed that two patients only showed non-specific abnormalities in EEG; scans were in all patients; all subjects exhibited diffuse cortical hypoperfusion. A strong correlation was always found between clinical presentation and hemispheric impairment. One patient exhibited asymmetrical perfusion between cerebellum hemispheres; intercritical SPET showed homogeneous distrubution of the radio-tracer in 4 patients. In the last one minimal residual hypoperfusion was observed, although less marked than in the acute phase. Therefore SPET with {sup 99m}Tc-HM PAO can be reasonably employed as the examination of choice when a migrain attack is clinically suspected, because of its reproducibility and reliability. It can be easily performed in every nuclear medical center supplied with modern tomographic cameras.

  4. Divergent strains of human T-lymphotropic virus type 1 (HTLV-1) within the Cosmopolitan subtype in Argentina.

    Science.gov (United States)

    Eirin, Maria E; Dilernia, Dario A; Berini, Carolina A; Jones, Leandro R; Pando, Maria A; Biglione, Mirna M

    2008-10-01

    HTLV-1 Cosmopolitan subtype Transcontinental subgroup A has been described among aboriginal communities from the northwest endemic area of Argentina. Moreover, Transcontinental subgroup A and the Japanese subgroup B were reported among blood donors from the nonendemic central region of the country. We carried out the first HTLV-1 phylogenetic study in individuals residing in Buenos Aires capital city. Phylogenetic analysis performed on the LTR region showed that all 44 new strains clustered within the Cosmopolitan subtype, with 42 (95.4%) belonging to Transcontinental subgroup A. Of them, 20 (45.5%) strains grouped in the large Latin American cluster and 4 (9.1%) in the small Latin American cluster. The majority of them belonged to individuals of nonblack origin, grouped with Amerindian strains. Three (6.8%) were closely related to South African references and two monophyletic clusters including only HIV/HTLV-1 coinfected individuals were observed. Interestingly, two (4.5%) new sequences (divergent strains) branched off from all five known Cosmopolitan subgroups in a well-supported clade. In summary, these findings show that HTLV-1 Cosmopolitan subtype Transcontinental subgroup A is infecting residents of Buenos Aires, a nonendemic area of Argentina, and confirm the introduction of divergent strains in the country.

  5. Functional analysis of a novel hydrogen peroxide resistance gene in Lactobacillus casei strain Shirota.

    Science.gov (United States)

    Serata, Masaki; Kiwaki, Mayumi; Iino, Tohru

    2016-11-01

    Lactic acid bacteria have a variety of mechanisms for tolerance to oxygen and reactive oxygen species, and these mechanisms differ among species. Lactobacillus casei strain Shirota grows well under aerobic conditions, indicating that the various systems involved in oxidative stress resistance function in this strain. To elucidate the mechanism of oxidative stress resistance in L. casei strain Shirota, we examined the transcriptome response to oxygen or hydrogen peroxide exposure. We then focused on an uncharacterized gene that was found to be up-regulated by both oxygen and hydrogen peroxide stress; we named the gene hprA1 (hydrogen peroxide resistance gene). This gene is widely distributed among lactobacilli. We investigated the involvement of this gene in oxidative stress resistance, as well as the mechanism of tolerance to hydrogen peroxide. Growth of L. casei MS105, an hprA1-disrupted mutant, was not affected by oxygen stress, whereas the survival rate of MS105 after hydrogen peroxide treatment was markedly reduced compared to that of the wild-type. However, the activity of MS105 in eliminating hydrogen peroxide was similar to that of the wild-type. We cloned hprA1 from L. caseiShirota and purified recombinant HprA1 protein from Escherichia coli. We demonstrated that the recombinant HprA1 protein bound to iron and prevented the formation of a hydroxyl radical in vitro. Thus, HprA1 protein probably contributes to hydrogen peroxide tolerance in L. casei strain Shirota by binding to iron in the cells and preventing the formation of a hydroxyl radical.

  6. Effects of age and liquid holding on the UV-radiation sensitivities of wild-type and mutant Caenorhabditis elegans dauer larvae

    Energy Technology Data Exchange (ETDEWEB)

    Hartman, P S

    1984-01-01

    The dauer larva is a facultative developmental stage in the life cycle of the nematode Caenorhabditis elegans. Dauer larvae, which can survive under starvation for over 60 days, resume normal development when feeding is resumed. Wild-type (N2) and 4 radiation-sensitive (rad) mutant dauer larvae were tested for their abilities to develop into adults after UV-irradiation. The rad-3 mutant was over 30 times as sensitive as N2; rad-1, rad-2 and rad-7 mutants were not hypersensitive. Irradiation also delayed development in survivors. Wild-type dauer larvae did not differ in radiation sensitivity from 0 through 50 days of age. There was no liquid holding recovery (LHR); that is, survival did not increase when wild-type dauer larvae were held in buffer after irradiation. (orig.). 28 refs.; 4 figs.

  7. Lactobacillus rodentium sp. nov., from the digestive tract of wild rodents.

    Science.gov (United States)

    Killer, J; Havlík, J; Vlková, E; Rada, V; Pechar, R; Benada, O; Kopečný, J; Kofroňová, O; Sechovcová, H

    2014-05-01

    Three strains of regular, long, Gram-stain-positive bacterial rods were isolated using TPY, M.R.S. and Rogosa agar under anaerobic conditions from the digestive tract of wild mice (Mus musculus). All 16S rRNA gene sequences of these isolates were most similar to sequences of Lactobacillus gasseri ATCC 33323T and Lactobacillus johnsonii ATCC 33200T (97.3% and 97.2% sequence similarities, respectively). The novel strains shared 99.2-99.6% 16S rRNA gene sequence similarities. Type strains of L. gasseri and L. johnsonii were also most related to the newly isolated strains according to rpoA (83.9-84.0% similarities), pheS (84.6-87.8%), atpA (86.2-87.7%), hsp60 (89.4-90.4%) and tuf (92.7-93.6%) gene sequence similarities. Phylogenetic studies based on 16S rRNA, hsp60, rpoA, atpA and pheS gene sequences, other genotypic and many phenotypic characteristics (results of API 50 CHL, Rapid ID 32A and API ZYM biochemical tests; cellular fatty acid profiles; cellular polar lipid profiles; end products of glucose fermentation) showed that these bacterial strains represent a novel species within the genus Lactobacillus. The name Lactobacillus rodentium sp. nov. is proposed to accommodate this group of new isolates. The type strain is MYMRS/TLU1T (=DSM 24759T=CCM 7945T).

  8. Typing of Lymphogranuloma Venereum Chlamydia trachomatis Strains

    Science.gov (United States)

    Christerson, Linus; de Vries, Henry J.C.; de Barbeyrac, Bertille; Gaydos, Charlotte A.; Henrich, Birgit; Hoffmann, Steen; Schachter, Julius; Thorvaldsen, Johannes; Vall-Mayans, Martí; Klint, Markus; Morré, Servaas A.

    2010-01-01

    We analyzed by multilocus sequence typing 77 lymphogranuloma venereum Chlamydia trachomatis strains from men who have sex with men in Europe and the United States. Specimens from an outbreak in 2003 in Europe were monoclonal. In contrast, several strains were in the United States in the 1980s, including a variant from Europe. PMID:21029543

  9. Construction and characterization of a glycoprotein E deletion mutant of bovine herpesvirus type 1.2 strain isolated in Brazil

    NARCIS (Netherlands)

    Franco, A.C.; Rijsewijk, F.A.M.; Flores, E.F.; Weiblen, R.; Roehe, P.M.

    2002-01-01

    This paper describes the construction and characterization of a Brazilian strain of bovine herpesvirus type 1.2a (BoHV-1.2a) with a deletion of the glycoprotein E (gE) gene. The deletion was introduced by co-transfection of a deletion fragment containing the 5´and 3´gE flanking regions and genomic

  10. Crystallization and preliminary X-ray crystallographic study of the wild type and two mutants of the CP1 hydrolytic domain from Aquifex aeolicus leucyl-tRNA synthetase

    Energy Technology Data Exchange (ETDEWEB)

    Cura, Vincent; Olieric, Natacha; Guichard, Alexandre [Département de Biologie et Génomique Structurales, UMR 7104, Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS/INSERM/ULP Strasbourg, 1 Rue Laurent Fries, 67404 Illkirch (France); Wang, En-Duo [State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, The Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai 200031 (China); Moras, Dino [Département de Biologie et Génomique Structurales, UMR 7104, Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS/INSERM/ULP Strasbourg, 1 Rue Laurent Fries, 67404 Illkirch (France); Eriani, Gilbert [Architecture et Réactivité de l’ARN, UPR 9002, Institut de Biologie Moléculaire et Cellulaire du CNRS, 15 Rue René Descartes, 67084 Strasbourg (France); Cavarelli, Jean, E-mail: cava@igbmc.u-strasbg.fr [Département de Biologie et Génomique Structurales, UMR 7104, Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS/INSERM/ULP Strasbourg, 1 Rue Laurent Fries, 67404 Illkirch (France)

    2005-10-01

    The wild-type editing CP1 domain of A. aeolicus leucyl-tRNA synthetase and two mutant CP1 domains have been overexpressed, purified and crystallized. X-ray diffraction data have been collected to 1.8 Å, which has enabled determination of the structures by molecular replacement. The editing or hydrolytic CP1 domain of leucyl-tRNA synthetase (LeuRS) hydrolyses several misactivated amino acids. The CP1 domain of Aquifex aeolicus LeuRS was expressed, purified and crystallized by the hanging-drop vapour-diffusion method using ammonium sulfate as precipitant. Crystals belong to space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 38.8, b = 98.4, c = 116.7 Å. Crystals diffract to beyond 1.8 Å resolution and contain two monomers in the asymmetric unit. Two CP1 mutants in which a conserved threonine residue essential for the fidelity of the hydrolytic pathway is mutated to alanine or glutamic acid have also been expressed and crystallized. Crystals of the two CP1 mutants are isomorphs of the wild type and diffract to beyond 1.9 Å resolution. All structures were solved by molecular-replacement techniques.

  11. Crystallization and preliminary X-ray crystallographic study of the wild type and two mutants of the CP1 hydrolytic domain from Aquifex aeolicus leucyl-tRNA synthetase

    International Nuclear Information System (INIS)

    Cura, Vincent; Olieric, Natacha; Guichard, Alexandre; Wang, En-Duo; Moras, Dino; Eriani, Gilbert; Cavarelli, Jean

    2005-01-01

    The wild-type editing CP1 domain of A. aeolicus leucyl-tRNA synthetase and two mutant CP1 domains have been overexpressed, purified and crystallized. X-ray diffraction data have been collected to 1.8 Å, which has enabled determination of the structures by molecular replacement. The editing or hydrolytic CP1 domain of leucyl-tRNA synthetase (LeuRS) hydrolyses several misactivated amino acids. The CP1 domain of Aquifex aeolicus LeuRS was expressed, purified and crystallized by the hanging-drop vapour-diffusion method using ammonium sulfate as precipitant. Crystals belong to space group P2 1 2 1 2 1 , with unit-cell parameters a = 38.8, b = 98.4, c = 116.7 Å. Crystals diffract to beyond 1.8 Å resolution and contain two monomers in the asymmetric unit. Two CP1 mutants in which a conserved threonine residue essential for the fidelity of the hydrolytic pathway is mutated to alanine or glutamic acid have also been expressed and crystallized. Crystals of the two CP1 mutants are isomorphs of the wild type and diffract to beyond 1.9 Å resolution. All structures were solved by molecular-replacement techniques

  12. Peptide-derivatized SB105-A10 dendrimer inhibits the infectivity of R5 and X4 HIV-1 strains in primary PBMCs and cervicovaginal histocultures.

    Directory of Open Access Journals (Sweden)

    Isabella Bon

    Full Text Available Peptide dendrimers are a class of molecules that exhibit a large array of biological effects including antiviral activity. In this report, we analyzed the antiviral activity of the peptide-derivatized SB105-A10 dendrimer, which is a tetra-branched dendrimer synthetized on a lysine core, in activated peripheral blood mononuclear cells (PBMCs that were challenged with reference and wild-type human immunodeficiency virus type 1 (HIV-1 strains. SB105-A10 inhibited infections by HIV-1 X4 and R5 strains, interfering with the early phases of the viral replication cycle. SB105-A10 targets heparan sulfate proteoglycans (HSPGs and, importantly, the surface plasmon resonance (SPR assay revealed that SB105-A10 strongly binds gp41 and gp120, most likely preventing HIV-1 attachment/entry through multiple mechanisms. Interestingly, the antiviral activity of SB105-A10 was also detectable in an organ-like structure of human cervicovaginal tissue, in which SB105-A10 inhibited the HIV-1ada R5 strain infection without altering the tissue viability. These results demonstrated the strong antiviral activity of SB105-A10 and suggest a potential microbicide use of this dendrimer to prevent the heterosexual transmission of HIV-1.

  13. Positron Emission Tomographic Imaging of the Cannabinoid Type 1 Receptor System with [11C]OMAR ([11C]JHU75528: Improvements in Image Quantification Using Wild-Type and Knockout Mice

    Directory of Open Access Journals (Sweden)

    Raúl Herance

    2011-11-01

    Full Text Available In this study, we assessed the feasibility of using positron emission tomography (PET and the tracer [11C]OMAR ([11C]JHU75528, an analogue of rimonabant, to study the brain cannabinoid type 1 (CB1 receptor system. Wild-type (WT andCB1 knockout (KO animals were imaged at baseline and after pretreatment with blocking doses of rimonabant. Brain uptake in WT animals was higher (50% than in KO animals in baseline conditions. After pretreatment with rimonabant, WT uptake lowered to the level of KO animals. The results of this study support the feasibility of using PET with the radiotracer [11C]JHU75528 to image the brain CB1 receptor system in mice. In addition, this methodology can be used to assess the effect of new drugs in preclinical studies using genetically manipulated animals.

  14. Phosphorylated EGFR expression may predict outcome of EGFR-TKIs therapy for the advanced NSCLC patients with wild-type EGFR

    Directory of Open Access Journals (Sweden)

    Wang Fen

    2012-08-01

    Full Text Available Abstract Background EGFR mutation is a strong predictive factor of EGFR-TKIs therapy. However, at least 10% of patients with EGFR wild-type are responsive to TKIs, suggesting that other determinants of outcome besides EGFR mutation might exist. We hypothesized that activation of phosphorylated EGFR could be a potential predictive biomarker to EGFR-TKIs treatment among patients in wild-type EGFR. Method Total of 205 stage IIIb and IV NSCLC patients, tissue samples of whom were available for molecular analysis, were enrolled in this study. The phosphorylation of EGFR at tyrosine 1068 (pTyr1068 and 1173 (pTyr1173 were assessed by immunohistochemistry, and EGFR mutations were detected by denaturing high performance liquid chromatograph (DHPLC. Results Among 205 patients assessable for EGFR mutation and phosphorylation analysis, 92 (44.9% were EGFR mutant and 165 patients (57.6% had pTyr1173 expression. Superior progression-free survival (PFS was seen after EGFR-TKIs therapy in patients with pTyr1068 expression compared to pTyr1068 negative ones (median PFS 7.0 months vs. 1.2 months, P P = 0.016. In subgroup of patients with wild-type EGFR, pTyr1068 expression positive ones had a significantly prolonged PFS (4.2 months vs.1.2 months P  Conclusion pTyr1068 may be a predictive biomarker for screening the population for clinical response to EGFR-TKIs treatment; especially for patients with wild-type EGFR.

  15. Partially dissecting the steady-state electron fluxes in Photosystem I in wild-type and pgr5 and ndh mutants of Arabidopsis

    Directory of Open Access Journals (Sweden)

    Jiancun eKou

    2015-09-01

    Full Text Available Cyclic electron flux (CEF around Photosystem I (PS I is difficult to quantify. We obtained the linear electron flux (LEFO2 through both photosystems and the total electron flux through PS I (ETR1 in Arabidopsis in CO2-enriched air. DeltaFlux = ETR1 – LEFO2 is an upper estimate of CEF, which consists of two components, an antimycin A-sensitive, PGR5 (proton gradient regulation 5 protein-dependent component and an insensitive component facilitated by a chloroplastic nicotinamide adenine dinucleotide dehydrogenase-like complex (NDH. Using wild type as well as pgr5 and ndh mutants, we observed that (1 40% of the absorbed light was partitioned to PS I; (2 at high irradiance a substantial antimycin A-sensitive CEF occurred in the wild type and the ndh mutant; (3 at low irradiance a sizable antimycin A-sensitive CEF occurred in the wild type but not in the ndh mutant, suggesting an enhancing effect of NDH in low light; and (4 in the pgr5 mutant, and the wild type and ndh mutant treated with antimycin A, a residual DeltaFlux existed at high irradiance, attributable to charge recombination and/or pseudo-cyclic electron flow. Therefore, in low-light-acclimated plants exposed to high light, DeltaFlux has contributions from various paths of electron flow through PS I.

  16. Sexual performance of mass reared and wild Mediterranean fruit flies (Diptera: Tephritidae) from various origins of the Madeira Islands

    International Nuclear Information System (INIS)

    Pereira, R.; Silva, N.; Quintal, C.; Abreu, R.; Andrade, J.; Dantas, L.

    2007-01-01

    The success of Mediterranean fruit fly (medfly) Ceratitis capitata (Wiedemann) control programs integrating the sterile insect technique (SIT) is based on the capacity of released the sterile males to compete in the field for mates. The Islands of Madeira are composed of 2 populated islands (Madeira and Porto Santo) where the medfly is present. To evaluate the compatibility and sexual performance of sterile flies we conducted a series of field cage tests. At same time, the process of laboratory domestication was evaluated. 3 wild populations, one semi-wild strain, and 1 mass reared strain were evaluated: the wild populations of (1) Madeira Island (north coast), (2) Madeira Island (south coast), and (3) Porto Santo Island; (4) the semi-wild population after 7 to 10 generations of domestication in the laboratory (respectively, for first and second experiment); and (5) the genetic sexing strain in use at Madeira medfly facility (VIENNA 7mix2000). Field cage experiments showed that populations of all origins are mostly compatible. There were no significant differences among wild populations in sexual competitiveness. Semi-wild and mass-reared males performed significantly poorer in both experiments than wild males in achieving matings with wild females. The study indicates that there is no significant isolation among strains tested, although mating performance is reduced in mass-reared and semi-wild flies after 7 to 10 generations in the laboratory. (author) [es

  17. Metabolic Engineering of Mannitol Production in Lactococcus lactis: Influence of Overexpression of Mannitol 1-Phosphate Dehydrogenase in Different Genetic Backgrounds

    NARCIS (Netherlands)

    Wisselink, H.W.; Mars, A.E.; Meer, van der P.; Eggink, G.; Hugenholtz, J.

    2004-01-01

    To obtain a mannitol-producing Lactococcus lactis strain, the mannitol 1-phosphate dehydrogenase gene (mtlD) from Lactobacillus plantarum was overexpressed in a wild-type strain, a lactate dehydrogenase(LDH)-deficient strain, and a strain with reduced phosphofructokinase activity. High-performance

  18. The effect of UVB on flavonoid biosynthesis in wild type and mutant petunia and arabidopsis

    International Nuclear Information System (INIS)

    Ryan, K.G.; Swinny, E.E.; Markham, K.R.; Winefield, C.

    2000-01-01

    Full text: Flavonoids may protect plants against damage by UVB radiation. Flavonoid composition and mRNA expression were determined following growth of plants under natural light, and under natural light with low UVB and with enhanced UVB. In wild-type Arabidopsis and Petunia, UVB induced an increase in total levels of flavonols and this was due to an up-regulation of, several genes coding for key enzymes in the phenylpropanoid pathway. In addition, UVB induced a higher rate of production of the di-hydroxylated si flavonol, quercetin glycoside than of the mono-hydroxylated equivalent, of kaempferol glycoside. Thus the ratio of quercetin to kaempferol increased with UVB treatment in wild type plants, and this suggests that the flavonoid r 3'hydroxylase (F3'H) enzyme, which converts dihydrokaempferol to dihydroquercetin, may play a key role in plant protection from UVB. Mutant plants of both species lacking this F3'H gene were grown under similar UV conditions. Leaves of the mutant Arabidopsis plant (tt7) did not contain quercetin, even under the enhanced UVB treatment. Under the low UVB treatment the total amount of flavonol was similar to the wild-type (Ler), but with increasing UVB, total flavonol (i.e. kaempferol) levels were significantly higher than in similarly treated wild type plants. In the Petunia F3'H mutant, low levels of quercetin were found even in the low UVB treatment, which indicates this variety may be producing some quercetin via an alternative pathway. Under UVB radiation, total flavonoids increased to levels significantly higher than in similarly treated wild type plants, and most of this material was kaempferol. These observations suggest that quercetin is the preferred protective flavonol in wild type plants, due perhaps to enhanced antioxidant or free radical scavenging activity. In mutant plants lacking the F3'H enzyme, the response is to produce a larger amount of a less effective photoprotectant

  19. Deduced sequences of the membrane fusion and attachment proteins of canine distemper viruses isolated from dogs and wild animals in Korea.

    Science.gov (United States)

    Bae, Chae-Wun; Lee, Joong-Bok; Park, Seung-Yong; Song, Chang-Seon; Lee, Nak-Hyung; Seo, Kun-Ho; Kang, Young-Sun; Park, Choi-Kyu; Choi, In-Soo

    2013-08-01

    Canine distemper virus (CDV) causes highly contagious respiratory, gastrointestinal, and neurological diseases in wild and domestic animal species. Despite a broad vaccination campaign, the disease is still a serious problem worldwide. In this study, six field CDV strains were isolated from three dogs, two raccoon dogs, and one badger in Korea. The full sequence of the genes encoding fusion (F) and hemagglutinin (H) proteins were compared with those of other CDVs including field and vaccine strains. The phylogenetic analysis for the F and H genes indicated that the two CDV strains isolated from dogs were most closely related to Chinese strains in the Asia-1 genotype. Another four strains were closely related to Japanese strains in the Asia-2 genotype. The six currently isolated strains shared 90.2-92.1% and 88.2-91.8% identities with eight commercial vaccine strains in their nucleotide and amino acid sequences of the F protein, respectively. They also showed 90.1-91.4% and 87.8-90.7% identities with the same vaccine strains in their nucleotide and deduced amino acid sequences of the H protein, respectively. Different N-linked glycosylation sites were identified in the F and H genes of the six isolates from the prototype vaccine strain Onderstepoort. Collectively, these results demonstrate that at least two different CDV genotypes currently exist in Korea. The considerable genetic differences between the vaccine strains and wild-type isolates would be a major factor of the incomplete protection of dogs from CDV infections.

  20. Special applications of [sup 99m]Tc-HM-PAO SPECT in the evaluation of cerebral hemodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Kobayashi, Shigeki; Kageyama, Yuhsuke (Chiba Emergency Medical Center (Japan)); Namba, Hiroki (and others)

    1991-12-01

    [sup 99m]Tc-HM-PAO has been widely used as a brain-perfusion tracer. It is known that this lipophilic tracer crosses the blood-brain barrier with a high-pass extraction fraction, is deposited in the brain proportional to the cerebral blood flow, and shows a nearly constant maintenance of the regional distribution over several hours. Taking advantage of these characteristics of the tracer, we evaluated changes in the cerebral blood flow before and after recanalization therapy in the acute stage of stroke. Recent advances in catheterization technique have made it possible to introduce a catheter superselectively into smaller cerebral vessels, such as anterior, middle, and posterior cerebral arteries and external carotid artery branches. We ourselves evaluated the areas and concentrations of anti-cancer agents by injecting HM-PAO through the microcatheter used for superselective intra-arterial chemotherapy. We also visualized the areas supplied by the grafted vessels after bypass surgery for ischemic cerebrovascular diseases by the superselective infusion of HM-PAO. We found these techniques to be useful in clinical neurosurgery. (author).

  1. Strain improvement of Gluconacetobacter xylinus NCIM 2526 for ...

    African Journals Online (AJOL)

    The present investigation demonstrates the effectiveness of ultraviolet (UV) radiation and ethyl methanesulfonate (EMS) in strain improvement for enhanced cellulose production by Gluconacetobacter xylinus NCIM 2526. The mutants were compared with wild type for cellulose production. UV mutants GHUV3, GHUV4, and ...

  2. Susceptibility of the wild-derived inbred CAST/Ei mouse to infection by orthopoxviruses analyzed by live bioluminescence imaging

    International Nuclear Information System (INIS)

    Americo, Jeffrey L.; Sood, Cindy L.; Cotter, Catherine A.; Vogel, Jodi L.; Kristie, Thomas M.; Moss, Bernard; Earl, Patricia L.

    2014-01-01

    Classical inbred mice are extensively used for virus research. However, we recently found that some wild-derived inbred mouse strains are more susceptible than classical strains to monkeypox virus. Experiments described here indicated that the 50% lethal dose of vaccinia virus (VACV) and cowpox virus (CPXV) were two logs lower in wild-derived inbred CAST/Ei mice than classical inbred BALB/c mice, whereas there was little difference in the susceptibility of the mouse strains to herpes simplex virus. Live bioluminescence imaging was used to follow spread of pathogenic and attenuated VACV strains and CPXV virus from nasal passages to organs in the chest and abdomen of CAST/Ei mice. Luminescence increased first in the head and then simultaneously in the chest and abdomen in a dose-dependent manner. The spreading kinetics was more rapid with VACV than CPXV although the peak photon flux was similar. These data suggest advantages of CAST/Ei mice for orthopoxvirus studies. - Highlights: • Wild-derived inbred CAST/Ei mice are susceptible to vaccinia virus and cowpox virus. • Morbidity and mortality from orthopoxviruses are greater in CAST/Ei than BALB/c mice. • Morbidity and mortality from herpes simplex virus type 1 are similar in both mice. • Imaging shows virus spread from nose to lungs, abdominal organs and brain. • Vaccinia virus spreads more rapidly than cowpox virus

  3. Susceptibility of the wild-derived inbred CAST/Ei mouse to infection by orthopoxviruses analyzed by live bioluminescence imaging

    Energy Technology Data Exchange (ETDEWEB)

    Americo, Jeffrey L.; Sood, Cindy L.; Cotter, Catherine A.; Vogel, Jodi L.; Kristie, Thomas M.; Moss, Bernard, E-mail: bmoss@nih.gov; Earl, Patricia L., E-mail: pearl@nih.gov

    2014-01-20

    Classical inbred mice are extensively used for virus research. However, we recently found that some wild-derived inbred mouse strains are more susceptible than classical strains to monkeypox virus. Experiments described here indicated that the 50% lethal dose of vaccinia virus (VACV) and cowpox virus (CPXV) were two logs lower in wild-derived inbred CAST/Ei mice than classical inbred BALB/c mice, whereas there was little difference in the susceptibility of the mouse strains to herpes simplex virus. Live bioluminescence imaging was used to follow spread of pathogenic and attenuated VACV strains and CPXV virus from nasal passages to organs in the chest and abdomen of CAST/Ei mice. Luminescence increased first in the head and then simultaneously in the chest and abdomen in a dose-dependent manner. The spreading kinetics was more rapid with VACV than CPXV although the peak photon flux was similar. These data suggest advantages of CAST/Ei mice for orthopoxvirus studies. - Highlights: • Wild-derived inbred CAST/Ei mice are susceptible to vaccinia virus and cowpox virus. • Morbidity and mortality from orthopoxviruses are greater in CAST/Ei than BALB/c mice. • Morbidity and mortality from herpes simplex virus type 1 are similar in both mice. • Imaging shows virus spread from nose to lungs, abdominal organs and brain. • Vaccinia virus spreads more rapidly than cowpox virus.

  4. Burkholderia type VI secretion systems have distinct roles in eukaryotic and bacterial cell interactions

    DEFF Research Database (Denmark)

    Schwarz, Sandra; West, T Eoin; Boyer, Frédéric

    2010-01-01

    . From a group of 31 diverse bacteria, we identified several organisms that competed less effectively against wild-type B. thai than a strain lacking T6SS-1 function. Inactivation of T6SS-1 renders B. thai greatly more susceptible to cell contact-induced stasis by Pseudomonas putida, Pseudomonas...... fluorescens and Serratia proteamaculans-leaving it 100- to 1000-fold less fit than the wild-type in competition experiments with these organisms. Flow cell biofilm assays showed that T6S-dependent interbacterial interactions are likely relevant in the environment. B. thai cells lacking T6SS-1 were rapidly...

  5. Metabolic Engineering of Light and Dark Biochemical Pathways in Wild-Type and Mutant Strains of Synechocystis PCC 6803 for Maximal, 24-Hour Production of Hydrogen Gas

    Energy Technology Data Exchange (ETDEWEB)

    Ely, Roger L.; Chaplen, Frank W.R.

    2014-03-11

    This project used the cyanobacterial species Synechocystis PCC 6803 to pursue two lines of inquiry, with each line addressing one of the two main factors affecting hydrogen (H2) production in Synechocystis PCC 6803: NADPH availability and O2 sensitivity. H2 production in Synechocystis PCC 6803 requires a very high NADPH:NADP+ ratio, that is, the NADP pool must be highly reduced, which can be problematic because several metabolic pathways potentially can act to raise or lower NADPH levels. Also, though the [NiFe]-hydrogenase in PCC 6803 is constitutively expressed, it is reversibly inactivated at very low O2 concentrations. Largely because of this O2 sensitivity and the requirement for high NADPH levels, a major portion of overall H2 production occurs under anoxic conditions in the dark, supported by breakdown of glycogen or other organic substrates accumulated during photosynthesis. Also, other factors, such as N or S limitation, pH changes, presence of other substances, or deletion of particular respiratory components, can affect light or dark H2 production. Therefore, in the first line of inquiry, under a number of culture conditions with wild type (WT) Synechocystis PCC 6803 cells and a mutant with impaired type I NADPH-dehydrogenase (NDH-1) function, we used H2 production profiling and metabolic flux analysis, with and without specific inhibitors, to examine systematically the pathways involved in light and dark H2 production. Results from this work provided rational bases for metabolic engineering to maximize photobiological H2 production on a 24-hour basis. In the second line of inquiry, we used site-directed mutagenesis to create mutants with hydrogenase enzymes exhibiting greater O2 tolerance. The research addressed the following four tasks: 1. Evaluate the effects of various culture conditions (N, S, or P limitation; light/dark; pH; exogenous organic carbon) on H2 production profiles of WT cells and an NDH-1 mutant; 2. Conduct metabolic flux analyses for

  6. Effects of respiratory rate, plateau pressure, and positive end-expiratory pressure on PaO2 oscillations after saline lavage.

    Science.gov (United States)

    Baumgardner, James E; Markstaller, Klaus; Pfeiffer, Birgit; Doebrich, Marcus; Otto, Cynthia M

    2002-12-15

    One of the proposed mechanisms of ventilator-associated lung injury is cyclic recruitment of atelectasis. Collapse of dependent lung regions with every breath should lead to large oscillations in PaO2 as shunt varies throughout the respiratory cycle. We placed a fluorescence-quenching PO2 probe in the brachiocephalic artery of six anesthetized rabbits after saline lavage. Using pressure-controlled ventilation with oxygen, ventilator settings were varied in random order over three levels of positive end-expiratory pressure (PEEP), respiratory rate (RR), and plateau pressure minus PEEP (Delta). Dependence of the amplitude of PaO2 oscillations on PEEP, RR, and Delta was modeled by multiple linear regression. Before lavage, arterial PO2 oscillations varied from 3 to 22 mm Hg. After lavage, arterial PO2 oscillations varied from 5 to 439 mm Hg. Response surfaces showed markedly nonlinear dependence of amplitude on PEEP, RR, and Delta. The large PaO2 oscillations observed provide evidence for cyclic recruitment in this model of lung injury. The important effect of RR on the magnitude of PaO2 oscillations suggests that the static behavior of atelectasis cannot be accurately extrapolated to predict dynamic behavior at realistic breathing frequencies.

  7. Proteomics of Arabidopsis Seed Germination : a Comparative Study of Wild-Type and Gibberellin-Deficient Seeds

    NARCIS (Netherlands)

    Gallardo, K.; Job, C.; Groot, S.P.C.; Puype, M.; Vandekerckhove, J.; Job, D.

    2002-01-01

    We examined the role of gibberellins (GAs) in germination of Arabidopsis seeds by a proteomic approach. For that purpose, we used two systems. The first system consisted of seeds of the GA-deficient ga1 mutant, and the second corresponded to wild-type seeds incubated in paclobutrazol, a specific GA

  8. Structural Data on the Periplasmic Aldehyde Oxidoreductase PaoABC from Escherichia coli: SAXS and Preliminary X-ray Crystallography Analysis

    Directory of Open Access Journals (Sweden)

    Ana Rita Otrelo-Cardoso

    2014-01-01

    Full Text Available The periplasmic aldehyde oxidoreductase PaoABC from Escherichia coli is a molybdenum enzyme involved in detoxification of aldehydes in the cell. It is an example of an αβγ heterotrimeric enzyme of the xanthine oxidase family of enzymes which does not dimerize via its molybdenum cofactor binding domain. In order to structurally characterize PaoABC, X-ray crystallography and small angle X-ray scattering (SAXS have been carried out. The protein crystallizes in the presence of 20% (w/v polyethylene glycol 3350 using the hanging-drop vapour diffusion method. Although crystals were initially twinned, several experiments were done to overcome twinning and lowering the crystallization temperature (293 K to 277 K was the solution to the problem. The non-twinned crystals used to solve the structure diffract X-rays to beyond 1.80 Å and belong to the C2 space group, with cell parameters a = 109.42 Å, b = 78.08 Å, c = 151.77 Å, β = 99.77°, and one molecule in the asymmetric unit. A molecular replacement solution was found for each subunit separately, using several proteins as search models. SAXS data of PaoABC were also collected showing that, in solution, the protein is also an αβγ heterotrimer.

  9. Effects of regionally applied heating on the respiration of wild type ...

    African Journals Online (AJOL)

    Nocturnal dark respiration (Rn) in wild type and transgenic soybean plants ... Illinois, USA under ambient and elevated CO2 conditions was examined in this study. ... Experimental plants were transferred to a controlled growth chamber at V4 ...

  10. Molecular typing of uropathogenic E. coli strains by the ERIC-PCR method.

    Science.gov (United States)

    Ardakani, Maryam Afkhami; Ranjbar, Reza

    2016-04-01

    Escherichia coli (E. coli) is the most common cause of urinary infections in hospitals. The aim of this study was to evaluate the ERIC-PCR method for molecular typing of uropathogenic E. coli strains isolated from hospitalized patients. In a cross sectional study, 98 E. coli samples were collected from urine samples taken from patients admitted to Baqiyatallah Hospital from June 2014 to January 2015. The disk agar diffusion method was used to determine antibiotic sensitivity. DNA proliferation based on repetitive intergenic consensus was used to classify the E. coli strains. The products of proliferation were electrophoresed on 1.5% agarose gel, and their dendrograms were drawn. The data were analyzed by online Insillico software. The method used in this research proliferated numerous bands (4-17 bands), ranging from 100 to 3000 base pairs. The detected strains were classified into six clusters (E1-E6) with 70% similarity between them. In this study, uropathogenic E. coli strains belonged to different genotypic clusters. It was found that ERIC-PCR had good differentiation power for molecular typing of uropathogenic E. coli strains isolated from the patients in the study.

  11. Ectopic expression of MdSPDS1 in sweet orange (Citrus sinensis Osbeck) reduces canker susceptibility: involvement of H₂O₂ production and transcriptional alteration.

    Science.gov (United States)

    Fu, Xing-Zheng; Chen, Chuan-Wu; Wang, Yin; Liu, Ji-Hong; Moriguchi, Takaya

    2011-03-28

    Enormous work has shown that polyamines are involved in a variety of physiological processes, but information is scarce on the potential of modifying disease response through genetic transformation of a polyamine biosynthetic gene. In the present work, an apple spermidine synthase gene (MdSPDS1) was introduced into sweet orange (Citrus sinensis Osbeck 'Anliucheng') via Agrobacterium-mediated transformation of embryogenic calluses. Two transgenic lines (TG4 and TG9) varied in the transgene expression and cellular endogenous polyamine contents. Pinprick inoculation demonstrated that the transgenic lines were less susceptible to Xanthomonas axonopodis pv. citri (Xac), the causal agent of citrus canker, than the wild type plants (WT). In addition, our data showed that upon Xac attack TG9 had significantly higher free spermine (Spm) and polyamine oxidase (PAO) activity when compared with the WT, concurrent with an apparent hypersensitive response and the accumulation of more H₂O₂. Pretreatment of TG9 leaves with guazatine acetate, an inhibitor of PAO, repressed PAO activity and reduced H₂O₂ accumulation, leading to more conspicuous disease symptoms than the controls when both were challenged with Xac. Moreover, mRNA levels of most of the defense-related genes involved in synthesis of pathogenesis-related protein and jasmonic acid were upregulated in TG9 than in the WT regardless of Xac infection. Our results demonstrated that overexpression of the MdSPDS1 gene prominently lowered the sensitivity of the transgenic plants to canker. This may be, at least partially, correlated with the generation of more H₂O₂ due to increased production of polyamines and enhanced PAO-mediated catabolism, triggering hypersensitive response or activation of defense-related genes.

  12. Evolutionary remodeling of global regulatory networks during long-term bacterial adaptation to human hosts

    DEFF Research Database (Denmark)

    Pedersen, Søren Damkiær; Yang, Lei; Molin, Søren

    2013-01-01

    of these genetic changes, we moved the specific mutations, alone and in combination, to the genome of the reference strain PAO1. The phenotypes of the engineered PAO1 derivatives showed striking similarities with phenotypes observed among the DK2 isolates. The phenotypes observed in the DK2 isolates and PAO1...

  13. Comparative analysis of the protein compositions between wild type and body color mutant of helicoverpa armigera adult

    International Nuclear Information System (INIS)

    He Lihua; Chen Jin'e; Liu Yan; Wang Yongqiang; Liu Peigang; Meng Zhiqi

    2012-01-01

    To gain an in-depth understanding of the fineness and regulation mechanism of body color mutant of Helicoverpa armigera Hbner, the protein composition differences between adult of dominant mutant, recessive mutant and wild type were studied using the SDS-PAGE combined with MALDI-TOF-TOF/MS and bioinformatics analysis. The results indicated that the protein composition of the dominant mutant and wild type had little difference. However, there were obvious differences between the recessive mutant and wild-type. Three specific stripe were chosen for mass spectrometry and bioinformatics analysis, and two types of proteins related to energy metabolism and cytoskeleton were identified. These findings suggested that the two types of proteins may be associated with occurrence and regulation of body color mutant traits of H. armigera. (authors)

  14. Dispersal and longevity of wild and mass-reared Anastrepha Ludens and Anastrepha Obliqua (Diptera: Tephritidae)

    International Nuclear Information System (INIS)

    Hernandez, E.; Orozco, D.; Flores Breceda, S.; Dominguez, J.

    2007-01-01

    The rates of dispersal and survival of sterile mass-reared laboratory flies and sterile wild flies of Anastrepha ludens (Loew) and Anastrepha obliqua (Macquart) were estimated and compared with a regular rectangular array of 64 food-baited traps spaced 60 m between traps around the release point in Tapachula Chiapas, Mexico. The traps were scored every day during the first week, and then every 3 d over a 30-d period. For A. obliqua, the number of males recaptured was higher than that of females, while for A. ludens, females were recaptured more frequently than males. The recapture rate for the wild strains ranged from 0.6-24.8% for A. ludens and 1.3-16.2% for A. obliqua and the corresponding ranges for the mass-reared strains were 0.5-7.1% and 0.5-3.0% respectively. The life expectancy was 4.7 d for wild and 4.3 d for mass-reared A. obliqua males but 3 and 2 d, respectively, for wild and mass-reared A. ludens males. The net displacement of A. ludens and A. obliqua ranged approximately from 100-250 m and took place mostly on the first day. Wild A. ludens moved to the northwest from the release point while the mass-reared strain moved to the west. The A. obliqua wild flies moved to the west, while the mass-reared strain shifted to the southwest. We discuss the implications of our findings as to the spacing and frequency of sterile fly releases for the suppression of wild populations. (author) [es

  15. POTENTIAL PRODUCTION OF CYCLOPIAZONIC ACID BY PENICILLIUM CAMEMBERTI STRAINS ISOLATED FROM CAMEMBERT TYPE CHEESE

    Directory of Open Access Journals (Sweden)

    Miroslava Císarová

    2012-10-01

    Full Text Available The aim of this study was to isolate the strains of fungi from Camembert type cheese, identify them and to test isolated strains of Penicillium camemberti for their ability to produce cyclopiazonic acid. The description of micro- and macromorphological features was used for identification of Penicillium camemberti strains. Strains were subsequently in vitro tested on their potential ability to produce mycotoxin cyclopiazonic acid (CPA. All of the 14 strains of Penicillium camemberti, which were obtained from 20 samples of Camembert type cheese, were cultivated 7, 14, 21, 27 and 30 days on CYA medium at 10±1°C, 15±1°C and 25±1°C in the dark. For determination of CPA production ability by P. camemberti isolates in vitro was TLC used. After 7 days of cultivation cyclopiazonic acid was produced only by 5 from 14 strains cultivated at all cultivation temperatures. After 14 and 21 days of cultivation was CPA produced by 6 strains at all of cultivation temperatures. After 27 and 30 days of cultivation was CPA identified in 7 strains cultivated at all temperatures of cultivation. The other strains also produced mycotoxin, however, not at each temperature. The most productive at all temperatures and after all days were 5 out of 14 tested strains (S9, S10, S13, S18 and S19. Strains S6 and S16 did not produce CPA at any temperature. The lowest production after all days of cultivation was found at 10±1 °C (44% and the highest at 25±1 °C (85%.

  16. Abscisic Acid–Responsive Guard Cell Metabolomes of Arabidopsis Wild-Type and gpa1 G-Protein Mutants[C][W

    Science.gov (United States)

    Jin, Xiaofen; Wang, Rui-Sheng; Zhu, Mengmeng; Jeon, Byeong Wook; Albert, Reka; Chen, Sixue; Assmann, Sarah M.

    2013-01-01

    Individual metabolites have been implicated in abscisic acid (ABA) signaling in guard cells, but a metabolite profile of this specialized cell type is lacking. We used liquid chromatography–multiple reaction monitoring mass spectrometry for targeted analysis of 85 signaling-related metabolites in Arabidopsis thaliana guard cell protoplasts over a time course of ABA treatment. The analysis utilized ∼350 million guard cell protoplasts from ∼30,000 plants of the Arabidopsis Columbia accession (Col) wild type and the heterotrimeric G-protein α subunit mutant, gpa1, which has ABA-hyposensitive stomata. These metabolomes revealed coordinated regulation of signaling metabolites in unrelated biochemical pathways. Metabolites clustered into different temporal modules in Col versus gpa1, with fewer metabolites showing ABA-altered profiles in gpa1. Ca2+-mobilizing agents sphingosine-1-phosphate and cyclic adenosine diphosphate ribose exhibited weaker ABA-stimulated increases in gpa1. Hormone metabolites were responsive to ABA, with generally greater responsiveness in Col than in gpa1. Most hormones also showed different ABA responses in guard cell versus mesophyll cell metabolomes. These findings suggest that ABA functions upstream to regulate other hormones, and are also consistent with G proteins modulating multiple hormonal signaling pathways. In particular, indole-3-acetic acid levels declined after ABA treatment in Col but not gpa1 guard cells. Consistent with this observation, the auxin antagonist α-(phenyl ethyl-2-one)-indole-3-acetic acid enhanced ABA-regulated stomatal movement and restored partial ABA sensitivity to gpa1. PMID:24368793

  17. Efficient Reassignment of a Frequent Serine Codon in Wild-Type Escherichia coli.

    Science.gov (United States)

    Ho, Joanne M; Reynolds, Noah M; Rivera, Keith; Connolly, Morgan; Guo, Li-Tao; Ling, Jiqiang; Pappin, Darryl J; Church, George M; Söll, Dieter

    2016-02-19

    Expansion of the genetic code through engineering the translation machinery has greatly increased the chemical repertoire of the proteome. This has been accomplished mainly by read-through of UAG or UGA stop codons by the noncanonical aminoacyl-tRNA of choice. While stop codon read-through involves competition with the translation release factors, sense codon reassignment entails competition with a large pool of endogenous tRNAs. We used an engineered pyrrolysyl-tRNA synthetase to incorporate 3-iodo-l-phenylalanine (3-I-Phe) at a number of different serine and leucine codons in wild-type Escherichia coli. Quantitative LC-MS/MS measurements of amino acid incorporation yields carried out in a selected reaction monitoring experiment revealed that the 3-I-Phe abundance at the Ser208AGU codon in superfolder GFP was 65 ± 17%. This method also allowed quantification of other amino acids (serine, 33 ± 17%; phenylalanine, 1 ± 1%; threonine, 1 ± 1%) that compete with 3-I-Phe at both the aminoacylation and decoding steps of translation for incorporation at the same codon position. Reassignments of different serine (AGU, AGC, UCG) and leucine (CUG) codons with the matching tRNA(Pyl) anticodon variants were met with varying success, and our findings provide a guideline for the choice of sense codons to be reassigned. Our results indicate that the 3-iodo-l-phenylalanyl-tRNA synthetase (IFRS)/tRNA(Pyl) pair can efficiently outcompete the cellular machinery to reassign select sense codons in wild-type E. coli.

  18. Phylogenetic analysis of the haemagglutinin gene of canine distemper virus strains detected from giant panda and raccoon dogs in China

    Science.gov (United States)

    2013-01-01

    Background Canine distemper virus (CDV) infects a variety of carnivores, including wild and domestic Canidae. In this study, we sequenced and phylogenetic analyses of the hemagglutinin (H) genes from eight canine distemper virus (CDV) isolates obtained from seven raccoon dogs (Nyctereutes procyonoides) and a giant panda (Ailuropoda melanoleuca) in China. Results Phylogenetic analysis of the partial hemagglutinin gene sequences showed close clustering for geographic lineages, clearly distinct from vaccine strains and other wild-type foreign CDV strains, all the CDV strains were characterized as Asia-1 genotype and were highly similar to each other (91.5-99.8% nt and 94.4-99.8% aa). The giant panda and raccoon dogs all were 549Y on the HA protein in this study, irrespective of the host species. Conclusions These findings enhance our knowledge of the genetic characteristics of Chinese CDV isolates, and may facilitate the development of effective strategies for monitoring and controlling CDV for wild canids and non-cainds in China. PMID:23566727

  19. [Standard algorithm of molecular typing of Yersinia pestis strains].

    Science.gov (United States)

    Eroshenko, G A; Odinokov, G N; Kukleva, L M; Pavlova, A I; Krasnov, Ia M; Shavina, N Iu; Guseva, N P; Vinogradova, N A; Kutyrev, V V

    2012-01-01

    Development of the standard algorithm of molecular typing of Yersinia pestis that ensures establishing of subspecies, biovar and focus membership of the studied isolate. Determination of the characteristic strain genotypes of plague infectious agent of main and nonmain subspecies from various natural foci of plague of the Russian Federation and the near abroad. Genotyping of 192 natural Y. pestis strains of main and nonmain subspecies was performed by using PCR methods, multilocus sequencing and multilocus analysis of variable tandem repeat number. A standard algorithm of molecular typing of plague infectious agent including several stages of Yersinia pestis differentiation by membership: in main and nonmain subspecies, various biovars of the main subspecies, specific subspecies; natural foci and geographic territories was developed. The algorithm is based on 3 typing methods--PCR, multilocus sequence typing and multilocus analysis of variable tandem repeat number using standard DNA targets--life support genes (terC, ilvN, inv, glpD, napA, rhaS and araC) and 7 loci of variable tandem repeats (ms01, ms04, ms06, ms07, ms46, ms62, ms70). The effectiveness of the developed algorithm is shown on the large number of natural Y. pestis strains. Characteristic sequence types of Y. pestis strains of various subspecies and biovars as well as MLVA7 genotypes of strains from natural foci of plague of the Russian Federation and the near abroad were established. The application of the developed algorithm will increase t