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Graphium species form a well-supported monophyletic lineage within the Microascales (Ascomycota). Members of this genus can be found in association with bark beetles, as well as on tree wounds and in soils. During surveys of bark and ambrosia beetle-associated fungi and cavities made by woodpeckers on hardwood trees in Poland, many isolates with an affinity to Graphium were recovered. They were identified based on their morphological characters and sequence data for the internal transcribed spacer (ITS), 28S rDNA, β-tubulin ( TUB2 ), and translation elongation factor 1-α ( TEF1 ) gene regions. The results revealed five new species, described here as G. brachiatum, G. longistipitatum, G. polonicum, G. radicatum , and G. trypophloei .

During surveys of insect-associated mycobiomes in Norway, Poland, and Russia, isolates with affinity to Graphilbum (Ophiostomatales, Ascomycota) were recovered. In this study, eight known Graphilbum species as well as the newly collected isolates were compared based on morphology and DNA sequence data for four gene regions. The results revealed seven new species, described here as G. acuminatum, G. carpaticum, G. curvidentis, G. furuicola, G. gorcense, G. interstitiale , and G. sexdentatum . In addition to these species, G. crescericum and G. sparsum were commonly found in Norway. All new species were recovered from conifers in association with bark beetles, cerambycid beetles, and weevils and were morphologically similar, predominantly with pesotum-like asexual morphs. Where sexual morphs were present, these were small ascomata with short necks and rod-shaped ascospores having hyaline sheaths. The results suggest that Graphilbum species are common members of the Ophiostomatales in conifer ecosystems.

Armillaria possesses several intriguing characteristics that have inspired wide interest in understanding phylogenetic relationships within and among species of this genus. Nuclear ribosomal DNA sequence-based analyses of Armillaria provide only limited information for phylogenetic studies among widely divergent taxa. More recent studies have shown that translation elongation factor 1-α (tef1) sequences are highly informative for phylogenetic analysis of Armillaria species within diverse global regions. This study used Neighbor-net and coalescence-based Bayesian analyses to examine phylogenetic relationships of newly determined and existing tef1 sequences derived from diverse Armillaria species from across the Northern Hemisphere, with Southern Hemisphere Armillaria species included for reference. Based on the Bayesian analysis of tef1 sequences, Armillaria species from the Northern Hemisphere are generally contained within the following four superclades, which are named according to the specific epithet of the most frequently cited species within the superclade: (i) Socialis/Tabescens (exannulate) superclade including Eurasian A. ectypa, North American A. socialis (A. tabescens), and Eurasian A. socialis (A. tabescens) clades; (ii) Mellea superclade including undescribed annulate North American Armillaria sp. (Mexico) and four separate clades of A. mellea (Europe and Iran, eastern Asia, and two groups from North America); (iii) Gallica superclade including Armillaria Nag E (Japan), multiple clades of A. gallica (Asia and Europe), A. calvescens (eastern North America), A. cepistipes (North America), A. altimontana (western USA), A. nabsnona (North America and Japan), and at least two A. gallica clades (North America); and (iv) Solidipes/Ostoyae superclade including two A. solidipes/ostoyae clades (North America), A. gemina (eastern USA), A. solidipes/ostoyae (Eurasia), A. cepistipes (Europe and Japan), A. sinapina (North America and Japan), and A. borealis (Eurasia) clade 2. Of note is that A. borealis (Eurasia) clade 1 appears basal to the Solidipes/Ostoyae and Gallica superclades. The Neighbor-net analysis showed similar phylogenetic relationships. This study further demonstrates the utility of tef1 for global phylogenetic studies of Armillaria species and provides critical insights into multiple taxonomic issues that warrant further study.

Extrinsic discoloration of teeth is an unwanted side-effect in connection with the use of the chemical plaque-preventive agent chlorhexidine. Individual differences in discoloration tendency have, however, been observed. In order to study the nature of these extrinsic discolorations a selection of 3 typical "stainers" and 3 "non-stainers" was made based on the individual tendency to develop extrinsic discolorations of teeth after a ten days rinsing with 0.2% chlorhexidine twice a day. The individual discoloration tendency was maintained through various plaque-preventive regimens. Interference with the retention of chlorhexidine by a cation demonstrated a close correlation between antiplaque activity and the discoloration tendency. A commercial oxidizing agent based on peroxy monosulfate showed the most promising properties in reducing this extrinsic discoloration without interfering with plaque-prevention.

Individual differences in tooth discoloration have been observed after using chlorhexidine mouth rinses. To study the correlation between retention of chlorhexidine and the discoloration tendency, two groups, 'stainers' and 'non-stainers', were selected. The following parameters were tested: initial retention of chlorhexidine in vivo, retention of chlorhexidine to saliva-coated hydroxyapatite in vitro, and prolonged release of chlorhexidine in vivo. The initial oral retention of chlorhexidine was identical for the two groups, whereas in vitro retention of hydroxyapatite and prolonged release of chlorhexidine in vivo were higher among 'stainers'.

Extrinsic discoloration of teeth has frequently been observed in connection with the use of chemical plaque-preventive agents. Preliminary investigations have indicated that oxidizing peroxymonosulfate may effectively reduce this discoloration without interfering with the plaque-preventive capacity of chlorhexidine. In the present experiment a 0.2% chlorhexidine and a 1% peroxymonosulfate solution were used for oral rinsing in a group of 50 military recruits. A double-blind experimental design was followed. The plaque-preventive capacity of chlorhexidine was maintained, and a marked reduction in extrinsic tooth discoloration could be observed.