Apparent virus contamination in biopharmaceutical product at centocor.

Out-of-specification (OOS) results were reported by a contract lab in the in vitro adventitious agent assay (AVA) for two products manufactured using mouse myeloma cells in perfusion bioreactors. Cytopathic effect observed for test article-inoculated MRC-5 monolayers resembled foci seen in tissue culture cells infected with transforming viruses. All reasonable known technologies, including highly sensitive, state-of-the-art methodologies and multiple, redundant, and orthogonal methods, were deployed to screen broadly for potential viral and microbial contaminants.

Assessment of differences in ascomycete communities in the rhizosphere of field-grown wheat and potato.

To assess effects of plant crop species on rhizosphere ascomycete communities in the field, we compared a wheat monoculture and an alternating crop rotation of wheat and potato. Rhizosphere soil samples were taken at different time points during the growing season in four consecutive years (1999-2002). An ascomycete-specific primer pair (ITS5-ITS4A) was used to amplify internal transcribed spacer (ITS) sequences from total DNA extracts from rhizosphere soil.

Ascomycete communities in the rhizosphere of field-grown wheat are not affected by introductions of genetically modified Pseudomonas putida WCS358r.

A long-term field experiment (1999-2002) was conducted to monitor effects on the indigenous microflora of Pseudomonas putida WCS358r and two transgenic derivatives constitutively producing phenazine-1-carboxylic acid (PCA) or 2,4-diacetylphloroglucinol (DAPG). The strains were introduced as seed coating on wheat into the same field plots each year. Rhizosphere populations of ascomycetes were analysed using denaturing gradient gel electrophoresis (DGGE).

Effects of Pseudomonas putida modified to produce phenazine-1-carboxylic acid and 2,4-diacetylphloroglucinol on the microflora of field grown wheat.

Pseudomonas putida WCS358r, genetically modified to have improved activity against soil-borne pathogens, was released into the rhizosphere of wheat. Two genetically modified derivatives carried the phz or the phl biosynthetic gene loci and constitutively produced either the antifungal compound phenazine-1-carboxylic acid (PCA) or the antifungal and antibacterial compound 2,4-diacetylphloroglucinol (DAPG). In 1997 and 1998, effects of single introductions of PCA producing derivatives on the indigenous microflora were studied.