Background: This paper is based on a theological symposium presented at the International Xenotransplantation Association's 14th Congress held in Baltimore, MD, September, 2017.
Methods: The information explores the Jewish, Christian and Muslim theological perceptions and perspectives about cross-species (ie pig-to-human) organ transplantation, the genetic alterations required in the organ-source pig, and their potential to influence individual acceptance of the procedure.
Results/conclusions: This work should not be considered as the ultimate word about individual theological views, but rather as part of an ongoing conversation that will hopefully lead to wider consideration and exploration of these issues as xenotransplantation science advances towards clinical trials.
Members of the genus Pseudomonas (sensu stricto) are important phytopathogens and agents of human infections, while other strains and species have beneficial bioremediation and biocontrol activities. Traditionally, these important species have been difficult to differentiate phenotypically; thus, rRNA lineage analyses have often been invoked. In this report, a newly developed approach is described to rapidly detect and distinguish fluorescent Pseudomonas isolates: PCR amplification of a Pseudomonas-specific 990-bp ribosomal RNA gene (rDNA) fragment [Appl.
View Article and Find Full Text PDFTo study individual and combined impacts of two important atmospheric trace gases, CO2 and O3, on C and N cycling in forest ecosystems; a multi-year experiment using a small-scale ponderosa pine (Pinus ponderosa Laws.) seedling/soil/litter system was initiated in April 1998. The experiment was conducted in outdoor, sun-lit chambers where aboveground and belowground ecological processes could be studied in detail.
View Article and Find Full Text PDFDecomposition of plant litter is a primary mechanism of nutrient recycling and redistribution in most terrestrial ecosystems. Previously we demonstrated by a nested PCR protocol that 20 distinctive nifH (the gene encoding nitrogenase reductase) HaeIII restriction fragment length polymorphism (RFLP) patterns were derived from bulk DNA associated with samples of plant litter and soil collected at one Douglas Fir (DF) forest [33]. Five of the nifH DNA patterns (II-VI) were dominant types in DF litter with characteristic fragments of 237-303 bp length, whereas samples from soil contained primarily seven other patterns 131-188 bp length (IX-XV).
View Article and Find Full Text PDFPCR-based genomic fingerprinting by use of enterobacterial repetitive intergenic consensus primers (ERIC-PCR) was evaluated for its use in fingerprinting DNA of mixed Gram-negative bacterial strains and BIOLOG Gram-negative (GN) microplate substrate communities. ERIC-PCR fingerprints of six different pure bacterial strains and a combined mixture of the strains were compared with fingerprints obtained by two more established methods: amplified ribosomal DNA restriction analysis (ARDRA) and random amplified polymorphic DNA analysis (RAPD-PCR). The ERIC-PCR fingerprint of the mixed strains was highly reproducible and was more species-specific and representative of the individual strain fingerprints than the ARDRA and RAPD-PCR fingerprints, respectively.
View Article and Find Full Text PDF> Abstract Rhizosphere bacterial communities of parental and two transgenic alfalfa (Medicago sativa L.) of isogenic background were compared based on metabolic fingerprinting using Biolog GN microplates and DNA fingerprinting of bacterial communities present in Biolog GN substrate wells by enterobacterial repetitive intergenic consensus sequence-PCR (ERIC-PCR). The two transgenic alfalfa expressed either bacterial (Bacillus licheniformis) genes for alpha-amylase or fungal (Phanerochaete chrysosporium) genes for Mn-dependent lignin peroxidase (Austin S, Bingham ET, Matthews DE, Shahan MN, Will J, Burgess RR, Euphytica 85:381-393).
View Article and Find Full Text PDFNitrogen-fixing microbial populations in a Douglas fir forest on the western slope of the Oregon Cascade Mountain Range were analyzed. The complexity of the nifH gene pool (nifH is the marker gene which encodes nitrogenase reductase) was assessed by performing nested PCR with bulk DNA extracted from plant litter and soil. The restriction fragment length polymorphisms (RFLPs) of PCR products obtained from litter were reproducibly different than the RFLPs of PCR products obtained from the underlying soil.
View Article and Find Full Text PDFPseudomonas species are plant, animal, and human pathogens; exhibit plant pathogen-suppressing properties useful in biological control; or express metabolic versatilities valued in biotechnology and bioremediation. Specific detection of Pseudomonas species in the environment may help us gain a more complete understanding of the ecological significance of these microorganisms. The objective of this study was to develop a PCR protocol for selective detection of Pseudomonas (sensu stricto) in environmental samples.
View Article and Find Full Text PDFA xylE-iceC transcriptional fusion was created by ligatinga DNA fragment harboring the cloned xylE structural gene from the TOL plasmid of Pseudomonas putida mt-2 into the cloned iceC gene of Pseudomonas syringae Cit7. This fusion construct was integrated into the chromosome of Pseudomonas syringae Cit7 by homologous recombination. Both cis-merodiploid strain Cit7m17 and marker exchange strain Cit7h69 produced the XylE gene product, catechol2,3-dioxygenase.
View Article and Find Full Text PDFA rapid direct-extraction method was used to obtain DNA from environmental soil samples. Heat, enzymes, and guanidine isothiocyanate were utilized to lyse cells. The DNA was purified by agarose gel electrophoresis, amplified with 16S rRNA-based primers by use of the polymerase chain reaction, and then digested with the restriction endonuclease PalI.
View Article and Find Full Text PDFThe efficacy of using genetically engineered microbes (GEMs) to degrade recalcitrant environmental toxicants was demonstrated by the application of Pseudomonas putida PP0301(pR0103) to an Oregon agricultural soil amended with 500 micrograms/g of a model xenobiotic, phenoxyacetic acid (PAA). P. putida PP0301(pR0103) is a constitutive degrader of 2,4-dichlorophenoxyacetate (2,4-D) and is also active on the non-inducing substrate, PAA.
View Article and Find Full Text PDFThis report summarizes and evaluates research from several laboratories that deals with the detection of ecological effects induced through exposure of microbes or plants to genetically engineered microorganisms (GEMs) and microbial pest control agents (MPCAs). Some 27 potential endpoints for measuring effects have been studied. Perturbations induced by GEMs have been detected in about one-half of these endpoints.
View Article and Find Full Text PDFPseudomonas putida PPO301 (pRO103), genetically engineered to degrade 2,4-dichlorophenoxyacetate, affected microbial populations and processes in a nonsterile xeric soil. In soil amended with 2,4-dichlorophenoxyacetate (500 micrograms/g soil) and inoculated with PPO301 (pRO103), the rate of evolution of carbon dioxide was retarded for approximately 35 days; there was a transient increase in dehydrogenase activity; and the number of fungal propagules decreased below detection after 18 days. In unamended soil inoculated with PPO301(pRO103), the rate of evolution of carbon dioxide and the dehydrogenase activity were unaffected, and the numbers of fungal propagules were reduced by about two orders of magnitude.
View Article and Find Full Text PDFAn assay system was developed for the enumeration of genetically engineered microorganisms expressing a deregulated 2,4-dichlorophenoxyacetate (TFD) monooxygenase, which converts phenoxyacetate (PAA) to phenol. In PAA-amended cultures of Pseudomonas aeruginosa PAO1C(pRO103) and Pseudomonas putida PPO301(pRO103), strains which express a deregulated TFD monooxygenase, phenol production was proportional to cell number. Phenol was reacted, under specific conditions, with a 4-aminoantipyrine dye to form an intensely colored dye-phenol complex (AAPPC), which when measured spectrophotometrically could detect as few as 10(3) cells per ml.
View Article and Find Full Text PDFA genetically engineered microorganism, Pseudomonas putida PPO301(pRO103), and the plasmidless parent strain, PPO301, were added at approximately 10 CFU/g of soil amended with 500 ppm of 2,4-dichlorophenoxyacetate (2,4-D) (500 mug/g). The degradation of 2,4-D and the accumulation of a single metabolite, identified by gas chromatography-mass spectrophotometry as 2,4-dichlorophenol (2,4-DCP), occurred only in soil inoculated with PPO301(pRO103), wherein 2,4-DCP accumulated to >70 ppm for 5 weeks and the concentration of 2,4-D was reduced to <100 ppm. Coincident with the accumulation of 2,4-DCP was a >400-fold decline in the numbers of fungal propagules and a marked reduction in the rate of CO(2) evolution, whereas 2,4-D did not depress either fungal propagules or respiration of the soil microbiota.
View Article and Find Full Text PDFOne form of commercial application of microorganisms, including genetically engineered microorganisms is as an aerosol. To study the effect of aerosol-induced stress on bacterial survival, nonrecombinant spontaneous antibiotic-resistant mutants of four organisms, Enterobacter cloacae, Erwinia herbicola, Klebsiella planticola, and Pseudomonas syringae, were sprayed in separate experiments in a greenhouse. Samples were collected over a distance of 15 m from the spray site for enumeration.
View Article and Find Full Text PDFPlasmid pJP4 enables Alcaligenes eutrophus JMP134 to degrade 3-chlorobenzoate and 2,4-dichlorophenoxyacetic acid (TFD). Plasmid pRO101 is a derivative of pJP4 obtained by insertion of Tn1721 into a nonessential region of pJP4. Plasmid pRO101 was transferred by conjugation to several Pseudomonas strains and to A.
View Article and Find Full Text PDFProspective experimental field evaluation of genetically engineered microorganisms, such as microbial pest control agents, raises issues of how to properly ascertain their fate and survival in the environment. Field trials with recombinant organisms must reflect requirements for sampling and monitoring. Field trials were conducted at Tulelake, Calif.
View Article and Find Full Text PDFAppl Environ Microbiol
February 1988
A computer simulation model was used to predict the dynamics of survival and conjugation of Pseudomonas cepacia (carrying the transmissible recombinant plasmid R388:Tn1721) with a nonrecombinant recipient strain in simple rhizosphere and phyllosphere microcosms. Plasmid transfer rates were derived for a mass action model, and donor and recipient survival were modeled as exponential growth and decay processes or both. Rate parameters were derived from laboratory studies in which donor and recipient strains were incubated in test tubes with a peat-vermiculite solution or on excised radish or bean leaves in petri dishes.
View Article and Find Full Text PDFAppl Environ Microbiol
January 1987
Four commonly used conjugation techniques, colony cross streak (CCS), broth mating (BM), combined spread plate (CSP), and membrane filtration (MF), were compared with each other regarding reliability, sensitivity, and complexity in evaluating the transfer of conjugative plasmids. Five plasmids representing several incompatibility groups plus a variety of laboratory and environmental isolates were used as mating pairs. The suitability of each method was evaluated for use in a routine assessment of the genetic stability of genetically engineered microorganisms.
View Article and Find Full Text PDFAppl Environ Microbiol
February 1986
Water, sediment, and shellfish from three Oregon estuaries were cultured for pathogenic Vibrio species. Non-O1 serovars of V. cholerae were the most common pathogenic Vibrio species recovered.
View Article and Find Full Text PDFNucleic acid composition of 17 cultures representing the type or neotype strains of 15 named Lactobacillus species was studied. Nucleic acid characterization of these isolates was accompanied by a comparative study of conventional phenotypic reactions. The overall guanine plus cytosine mean deoxyribonucleic acid base composition ranged from 33 to 50% and genome sizes varied between 700 and 1500 X 10(6) daltons.
View Article and Find Full Text PDFWater samples from rivers, streams, ponds, and activated sewage were tested for the presence of bacteria which utilize 2,4-dichlorophenoxyacetic acid (2,4-D) as a sole source of carbon. Seventy percent of the attempted enrichments yielded pure cultures of 2,4-D-metabolizing bacteria. All but 1 of the 30 isolates were gram-negative rods, all but 2 were motile, and all were nonfermentative and oxidase and catalase positive.
View Article and Find Full Text PDFOuchterlony immunodiffusion of sonicated Vibrio vulnificus cells illustrated a single major precipitation line with antiserum prepared from whole cells of the same species. Antigenic analysis by two-dimensional immunoelectrophoresis verified the presence of a single dominant precipitation line. Tandem two-dimensional immunoelectrophoretic analyses of V.
View Article and Find Full Text PDFAn antigen common to Vibrio vulnificus strains, designated VVA, was purified by ammonium sulfate precipitation, gel filtration, ion-exchange column chromatography, and preparative gel electrophoresis. The molecular weight of VVA was 64,000 when estimated by gel filtration and 40,000 when measured by denaturing polyacrylamide gel electrophoresis. Antiserum prepared against purified VVA (anti-VVA serum) did not agglutinate whole cells of V.
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