Viscospora peruviscosa, a new fungus in the Glomeraceae from a plantation of Theobroma cacao in Peru

A new fungus, Viscospora peruviscosa, was detected in a Theobroma cacao plantation in the Huallaga province of San Martín State in Peru.The fungus was propagated in the greenhouse on Sorghum vulgare and Brachiaria brizantha. The fungus is similar to V. viscosa as it has two spore wall layers and also a viscose outer spore surface, but its spores are smaller ((30-) 44-56 (-65) × (25-) 44-54 μm) and the subtending hyphae generally are more pronounced funnel-shaped. Also, the walls of the spores and subtending hyphae are thinner than in V. viscosa. Phylogenetically, both species form two well separated sister clades in the genus Viscospora. Based on the partial nrDNA gene, the two species have 90-91% maximum identity (MI). So far, the fungus is only known from the cacao plantation in Huallaga. No environmental sequences in the public data bases suggest that the fungus has already been found elsewhere in the neotropics or worldwide. This is the second species in the genus Viscospora (Glomeraceae) described, hence Viscospora is no longer monospecific

Partially Assembled K99 Fimbriae Are Required for Protection

Antibodies to K99 fimbriae afford protection to F5(+) bovine enterotoxigenic Escherichia coli (ETEC). Previous studies show that murine dams immunized with Salmonella vaccine vectors stably expressing K99 fimbriae confer protection to ETEC-challenged neonatal pups. To begin to address adaptation of the K99 scaffold to display heterologous B- and T-cell epitopes, studies were conducted to determine how much of the assembled K99 fimbria is required to maintain protective immunity. Sequential deletions in the K99 gene clusters were made, resulting in diminished localization of the K99 fimbrial subunit in the outer membrane. As placement of the K99 fimbrial subunit became progressively contained within the vaccine vector, diminished immunoglobulin A (IgA) and IgG1 antibody titers, as well as diminished Th2-type cytokine responses, were observed in orally immunized mice. Deletion of fanGH, which greatly reduced the export of the fimbrial subunit to the outer membrane, showed only partial reduction in protective immunity. By contrast, deletion of fanDEFGH, which also reduced the export of the fimbrial subunit to the outer membrane but retained more subunit in the cytoplasm, resulted in protective immunity being dramatically reduced. Thus, these studies showed that retention of K99 fimbrial subunit as native fimbriae or with the deletion of fanGH is sufficient to confer protection