6 research outputs found
A molecular phylogenetic reappraisal of the Hysteriaceae, Mytilinidiaceae and Gloniaceae (Pleosporomycetidae, Dothideomycetes) with keys to world species
A reappraisal of the phylogenetic integrity of bitunicate ascomycete fungi
belonging to or previously affiliated with the Hysteriaceae,
Mytilinidiaceae, Gloniaceae and Patellariaceae is
presented, based on an analysis of 121 isolates and four nuclear genes, the
ribosomal large and small subunits, transcription elongation factor 1 and the
second largest RNA polymerase II subunit. A geographically diverse and high
density taxon sampling strategy was employed, including multiple
isolates/species from the following genera: Anteaglonium (6/4),
Encephalographa (1/1), Farlowiella (3/1),
Gloniopsis (8/4), Glonium (4/2), Hysterium (12/5),
Hysterobrevium (14/3), Hysterographium (2/1),
Hysteropatella (2/2), Lophium (4/2), Mytilinidion
(13/10), Oedohysterium (5/3), Ostreichnion (2/2),
Patellaria (1/1), Psiloglonium (11/3), Quasiconcha
(1/1), Rhytidhysteron (8/3), and 24 outgroup taxa. Sequence data
indicate that although the Hysteriales are closely related to the
Pleosporales, sufficient branch support exists for their separation
into separate orders within the Pleosporomycetidae. The
Mytilinidiales are more distantly related within the subclass and
show a close association with the Gloniaceae. Although there are
examples of concordance between morphological and molecular data, these are
few. Molecular data instead support the premise of a large number of
convergent evolutionary lineages, which do not correspond to previously held
assumptions of synapomorphy relating to spore morphology. Thus, within the
Hysteriaceae, the genera Gloniopsis, Glonium,
Hysterium and Hysterographium are highly polyphyletic. This
necessitated the transfer of two species of Hysterium to
Oedohysterium gen. nov. (Od. insidens comb.
nov. and Od. sinense comb. nov.), the description of a new
species, Hysterium barrianum sp. nov., and the transfer of
two species of Gloniopsis to Hysterobrevium gen.
nov. (Hb. smilacis comb. nov. and Hb.
constrictum comb. nov.). While Hysterographium, with
the type Hg. fraxini, is removed from the Hysteriaceae, some
of its species remain within the family, transferred here to
Oedohysterium (Od. pulchrum comb. nov.),
Hysterobrevium (Hb. mori comb. nov.) and
Gloniopsis (Gp. subrugosa comb. nov.); the latter
genus, in addition to the type, Gp. praelonga, with two new species,
Gp. arciformis sp. nov. and Gp. kenyensis sp. nov.
The genus Glonium is now divided into Anteaglonium
(Pleosporales), Glonium (Gloniaceae), and
Psiloglonium (Hysteriaceae). The hysterothecium has evolved
convergently no less than five times within the Pleosporomycetidae
(e.g., Anteaglonium, Farlowiella, Glonium,
Hysterographium and the Hysteriaceae). Similarly,
thin-walled mytilinidioid (e.g., Ostreichnion) and patellarioid
(e.g., Rhytidhysteron) genera, previously in the
Mytilinidiaceae and Patellariaceae, respectively,
transferred here to the Hysteriaceae, have also evolved at least
twice within the subclass. As such, character states traditionally considered
to represent synapomorphies among these fungi, whether they relate to spore
septation or the ascomata, in fact, represent symplesiomorphies, and most
likely have arisen multiple times through convergent evolutionary processes in
response to common selective pressures
Molecular phylogenetics of Pleosporales: Melanommataceae and Lophiostomataceae re-circumscribed (Pleosporomycetidae, Dothideomycetes, Ascomycota)
The classification of Pleosporales has posed major challenges due
to the lack of clear understanding of the importance of the morphological
characters used to distinguish between different groups in the order. This has
resulted in varied taxonomic treatments of many families in the group
including Melanommataceae and Lophiostomataceae. In this
study we employ two nuclear DNA gene markers, nuclear ribosomal large subunit
DNA and translation elongation factor 1-alpha in order to examine the
molecular phylogenetics of Pleosporales with strong emphasis on the
families Melanommataceae and Lophiostomataceae. Phylogenetic
analyses recovered Melanommataceae, Lophiostomataceae,
Hypsostromataceae, and a few others as strongly supported clades
within the Pleosporales. Melanommataceae as currently
circumscribed was found to be polyphyletic. The genera Byssosphaeria,
Melanomma, and Pseudotrichia were recovered within the family,
while others such as Ostropella and Xenolophium nested
outside in a weakly supported group along with Platystomum compressum
and Pseudotrichia guatopoensis that may correspond to the family
Platystomaceae. The genus Byssosphaeria was recovered as a
strongly supported group within the Melanommataceae while
Melanomma was weakly supported with unclear relationships among the
species. The genera Herpotrichia and Bertiella were also
found to belong in the Melanommataceae. Lophiostomataceae
occurs as a strongly supported group but its concept is here expanded to
include a new genus Misturatosphaeria that bears morphology
traditionally not known to occur in the family. The strongly supported clade
of Misturatosphaeria contains nine species that have gregarious,
papillate ascomata with lighter coloured apices and plugged ostioles and that
vary in ascospore morphology from 1- to 3-septate to muriform. Along with a
strongly supported Lophiostoma clade, also within the family are
Thyridaria macrostomoides based on new sequences from Kenyan
collections and Massariosphaeria triseptata, M. grandispora, Westerdykella
cylindrica and Preussia terricola based on GenBank sequences.
The family Hypsostromataceae was recovered as a strongly supported
monophyletic group nested within the Pleosporales
A class-wide phylogenetic assessment of Dothideomycetes
We present a comprehensive phylogeny derived from 5 genes, nucSSU, nucLSU
rDNA, TEF1, RPB1 and RPB2, for 356 isolates and 41
families (six newly described in this volume) in Dothideomycetes. All
currently accepted orders in the class are represented for the first time in
addition to numerous previously unplaced lineages. Subclass
Pleosporomycetidae is expanded to include the aquatic order
Jahnulales. An ancestral reconstruction of basic nutritional modes
supports numerous transitions from saprobic life histories to plant associated
and lichenised modes and a transition from terrestrial to aquatic habitats are
confirmed. Finally, a genomic comparison of 6 dothideomycete genomes with
other fungi finds a high level of unique protein associated with the class,
supporting its delineation as a separate taxon
A class-wide phylogenetic assessment of Dothideomycetes
We present a comprehensive phylogeny derived from 5 genes, nucSSU, nucLSU rDNA, TEF1, RPB1 and RPB2, for 356 isolates and 41 families (six newly described in this volume) in Dothideomycetes. All currently accepted orders in the class are represented for the first time in addition to numerous previously unplaced lineages. Subclass Pleosporomycetidae is expanded to include the aquatic order Jahnulales. An ancestral reconstruction of basic nutritional modes supports numerous transitions from saprobic life histories to plant associated and lichenised modes and a transition from terrestrial to aquatic habitats are confirmed. Finally, a genomic comparison of 6 dothideomycete genomes with other fungi finds a high level of unique protein associated with the class, supporting its delineation as a separate taxon
The ASOS Surgical Risk Calculator: development and validation of a tool for identifying African surgical patients at risk of severe postoperative complications
Background:
The African Surgical Outcomes Study (ASOS) showed that surgical patients in Africa have a mortality twice the global average. Existing risk assessment tools are not valid for use in this population because the pattern of risk for poor outcomes differs from high-income countries. The objective of this study was to derive and validate a simple, preoperative risk stratification tool to identify African surgical patients at risk for in-hospital postoperative mortality and severe complications.
Methods:
ASOS was a 7-day prospective cohort study of adult patients undergoing surgery in Africa. The ASOS Surgical Risk Calculator was constructed with a multivariable logistic regression model for the outcome of in-hospital mortality and severe postoperative complications. The following preoperative risk factors were entered into the model; age, sex, smoking status, ASA physical status, preoperative chronic comorbid conditions, indication for surgery, urgency, severity, and type of surgery.
Results:
The model was derived from 8799 patients from 168 African hospitals. The composite outcome of severe postoperative complications and death occurred in 423/8799 (4.8%) patients. The ASOS Surgical Risk Calculator includes the following risk factors: age, ASA physical status, indication for surgery, urgency, severity, and type of surgery. The model showed good discrimination with an area under the receiver operating characteristic curve of 0.805 and good calibration with c-statistic corrected for optimism of 0.784.
Conclusions:
This simple preoperative risk calculator could be used to identify high-risk surgical patients in African hospitals and facilitate increased postoperative surveillance.
© 2018 British Journal of Anaesthesia. Published by Elsevier Ltd. All rights reserved.Medical Research Council of South Africa gran