Prosopidicola mexicana gen. et sp. nov., causing a new pod disease of Prosopis species

Species of Prosopis introduced into South Africa from the Americas for fuel wood, shade and fodder, have become naturalized and widespread in the dry northwestern areas of this country. Invasive Prosopis species have been the target of a biological control programme in South Africa since 1985. During a survey for potential fungal biological control agents in Mexico and Texas in 2001, a pod disease was recorded on Prosopis glandulosa in both countries. The disease is characterized by black/grey pycnidia, flattening of the pods, and seed decay. Morphological investigations of the causal organism showed it to be a Coniothyrium-like, coelomycete. However, based on conidiogenous cell morphology and proliferation, we concluded that the organism is not congeneric with Coniothyrium s. str. Phylogenetic analysis of the SSU gene placed this fungus in the Diaporthales. Parsimony analysis of the ITS region (ITS-1, 5.8S, ITS-2) revealed it to group closely to Cryphonectria and Endothia. Consequently, a new genus, Prosopidicola, with type species Prosopidicola mexicana, is proposed

Lesional Antibody Synthesis and Complement Deposition Associate With De Novo Antineuronal Antibody Synthesis After Spinal Cord Injury

BACKGROUND AND OBJECTIVES: Spinal cord injury (SCI) disrupts the fine-balanced interaction between the CNS and immune system and can cause maladaptive aberrant immune responses. The study examines emerging autoantibody synthesis after SCI with binding to conformational spinal cord epitopes and surface peptides located on the intact neuronal membrane. METHODS: This is a prospective longitudinal cohort study conducted in acute care and inpatient rehabilitation centers in conjunction with a neuropathologic case-control study in archival tissue samples ranging from acute injury (baseline) to several months thereafter (follow-up). In the cohort study, serum autoantibody binding was examined in a blinded manner using tissue-based assays (TBAs) and dorsal root ganglia (DRG) neuronal cultures. Groups with traumatic motor complete SCI vs motor incomplete SCI vs isolated vertebral fracture without SCI (controls) were compared. In the neuropathologic study, B cell infiltration and antibody synthesis at the spinal lesion site were examined by comparing SCI with neuropathologically unaltered cord tissue. In addition, the CSF in an individual patient was explored. RESULTS: Emerging autoantibody binding in both TBA and DRG assessments was restricted to an SCI patient subpopulation only (16%, 9/55 sera) while being absent in vertebral fracture controls (0%, 0/19 sera). Autoantibody binding to the spinal cord characteristically detected the substantia gelatinosa, a less-myelinated region of high synaptic density involved in sensory-motor integration and pain processing. Autoantibody binding was most frequent after motor complete SCI (grade American Spinal Injury Association impairment scale A/B, 22%, 8/37 sera) and was associated with neuropathic pain medication. In conjunction, the neuropathologic study demonstrated lesional spinal infiltration of B cells (CD20, CD79a) in 27% (6/22) of patients with SCI, the presence of plasma cells (CD138) in 9% (2/22). IgG and IgM antibody syntheses colocalized to areas of activated complement (C9neo) deposition. Longitudinal CSF analysis of an additional single patient demonstrated de novo (IgM) intrathecal antibody synthesis emerging with late reopening of the blood-spinal cord barrier. DISCUSSION: This study provides immunologic, neurobiological, and neuropathologic proof-of-principle for an antibody-mediated autoimmunity response emerging approximately 3 weeks after SCI in a patient subpopulation with a high demand of neuropathic pain medication. Emerging autoimmunity directed against specific spinal cord and neuronal epitopes suggests the existence of paratraumatic CNS autoimmune syndromes

Characterisation of <I>Alternaria </i>species-groups associated with core rot of apples in South Africa.

AgriwetenskappePlantpatologiePlease help us populate SUNScholar with the post print version of this article. It can be e-mailed to: [email protected]

Endophytic fungi associated with core rot of apples in South Africa, with specific reference to Alternaria species

Apple fruits were sampled at five stages of development for endophytic colonisation by fungi associated with core rot, a major post-harvest disease. In addition, isolations were made from diseased core tissues of apples after 8 months of cold storage. The cultivars Top Red (susceptible to core rot) and Granny Smith (resistant to core rot) were sampled in orchards during the 1995/6 growing season. Of the 40 different fungal taxa encountered, 19 had a relative importance (RI) value of more than 10%. In general, more fungal isolates were obtained from Top Red than from Granny Smith apples, but no tissue specificity was detected. As found in previous studies, the Alternaria complex was the most dominant, representing 57% of the total number of 1602 isolates. On the basis of sporulation patterns and spore morphology, this complex could be divided into two different groups in the Alternaria alternata, two in the Alternaria infectoria, and one in the Alternaria tenuissima complexes. A further group was identified which may represent an additional Alternaria species. This study has further shown that the Alternaria spp. are present as endophytes already at the bud development stage, which has serious implications for any programme using fungicides for disease control.Articl

Fungal associations in Asphondylia (Diptera: Cecidomyiidae) galls from Australia and South Africa: implications for biological control of invasive acacias

Gall-forming Asphondylia are well represented on Australian Acacia and have potential for biological control where Australian acacias cause ecological or economic harm, particularly South Africa. Asphondylia in Australia and South Africa are associated with communities of fungi in their galls. In Australia, Botryosphaeria dothidea (as its Dichomera synanamorph) is the most abundant and sometimes the only fungus present and is implicated as the primary species forming a mutualistic relationship with Asphondylia. In the combined analysis of ITS and elongation factor 1-α sequence data, isolates of B. dothidea from Australia and South Africa form distinct sub-clades. Female Asphondylia carry B. dothidea (as Dichomera conidia) in mycangia located posterior to sternite 7. While conidia are always present on field-collected specimens, laboratory-reared females rarely carry conidia. The mechanism and location of spore collection remains unresolved, but needs to be understood if Asphondylia species are to be utilised for biological control of invasive Australian acacias. As B. dothidea is a polyphagous plant pathogen capable of infecting crops of economic importance, including Acacia plantations, the introduction of novel strains of B. dothidea associated with biological control of acacia is undesirable, however endemic forms of the fungus could possibly be exploited by introduced Asphondylia