David E Tribe

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A multilocus sequence typing (MLST) scheme has been developed for Enterococcus faecium. Internal fragments from seven housekeeping genes of 123 epidemiologically unlinked isolates from humans and livestock and 16 human-derived isolates from several outbreaks in the United States, the United Kingdom, Australia, and The Netherlands were analyzed. A total of(More)
In the USA, vancomycin-resistant Enterococcus faecium (VREF) is endemic in hospitals, despite lack of carriage among healthy individuals. In Europe, however, hospital outbreaks are rare, but VREF carriage among healthy individuals and livestock is common. We used amplified fragment-length polymorphism analysis to genotype 120 VREF isolates associated with(More)
Two major clades, designated Groups I and II, of nucleopolyhedroviruses (NPVs) from lepidopteran hosts have been previously identified. To reveal more detailed relationships, a series of DNA polymerase nucleotide sequences from the taxa MbMNPV, SeMNPV, HzSNPV, HearNPV, SpltNPV, BusuNPV, and OranNPV have been determined using a polymerase chain reaction(More)
The polyhedrin gene (polh) of Helicoverpa zea single nucleocapsid nuclear polyhedrosis virus (HzSNPV) was identified and shown by sequence analysis of the EcoRI I genomic fragment to encode a 246 amino acid polypeptide that has greater than 80% sequence identity to known polyhedrins. It is preceded by an AT-rich region containing the conserved late promoter(More)
Rapid accumulation of few polyhedra (FP) mutants was detected during serial passaging of Helicoverpa armigera nucleopolyhedrovirus (HaSNPV) in cell culture. 100% FP infected cells were observed by passage 6. The specific yield decreased from 178 polyhedra per cell at passage 2 to two polyhedra per cell at passage 6. The polyhedra at passage 6 were not(More)
Nucleotide sequence analysis of the Helicoverpa zea S-type nucleopolyhedrovirus (HzSNPV) genomic interval between the polh and iel genes has revealed an open reading frame (HOAR ORF) that contains a complex A 1-T rich triplet repeat region (RAT-repeats). HOAR ORF is predicted to encode an acidic, arginine residue rich. 712 aa protein, with a C3HC4(More)
Studies on the growth ofZ.mobilis revealed that high concentrations of glucose (10-25%) can be efficiently and rapidly converted to ethanol in batch culture. By comparison withS. carlsbergensis,Z.mobilis had specific glucose uptake rates and specific ethanol productivies several times greater than the yeast.Z.mobilis also had ethanol yields of up to 97% of(More)
Cell recycle studies have been carried out with a strain of Zymomonas mobilis selected for its improved ethanol tolerance and faster rates of glucose uptake and ethanol production. As part of the investigation a capilliary cross-flow microfiltration unit with polyamide membranes has been evaluated in view of its potential advantages (low cost and ability to(More)
Conversion of glucose and ammonium salts into tryptophan by mutants of Escherichia coli was examined as part of a feasibility study on the manufacture of tryptophan. This involved construction, largely by transduction, or a variety of multiple-mutation strains with defined genotypes. By comparing the properties of these strains, we were able to define in(More)