MSSA IE isolates were significantly more likely to be CC30 and to possess a distinct repertoire of virulence genes than MSSA STI isolates from the same region. The genetic basis of this association requires further study.

Novel species of fungi described in this study include those from various countries as follows: Antarctica: Cadophora antarctica from soil. Australia: Alfaria dandenongensis on Cyperaceae, Amphosoma persooniae on Persoonia sp., Anungitea nullicana on Eucalyptus sp., Bagadiella eucalypti on Eucalyptus globulus, Castanediella eucalyptigena on Eucalyptus sp., Cercospora dianellicola on Dianella sp., Cladoriella kinglakensis on Eucalyptus regnans, Cladoriella xanthorrhoeae (incl. Cladoriellaceae fam. nov. and Cladoriellales ord. nov.) on Xanthorrhoea sp., Cochlearomyces eucalypti (incl. Cochlearomyces gen. nov. and Cochlearomycetaceae fam. nov.) on Eucalyptus obliqua, Codinaea lambertiae on Lambertia formosa, Diaporthe obtusifoliae on Acacia obtusifolia, Didymella acaciae on Acacia melanoxylon, Dothidea eucalypti on Eucalyptus dalrympleana, Fitzroyomyces cyperi (incl. Fitzroyomyces gen. nov.) on Cyperaceae, Murramarangomyces corymbiae (incl. Murramarangomyces gen. nov., Murramarangomycetaceae fam. nov. and Murramarangomycetales ord. nov.) on Corymbia maculata, Neoanungitea eucalypti (incl. Neoanungitea gen. nov.) on Eucalyptus obliqua, Neoconiothyrium persooniae (incl. Neoconiothyrium gen. nov.) on Persoonia laurina subsp. laurina, Neocrinula lambertiae (incl. Neocrinulaceae fam. nov.) on Lambertia sp., Ochroconis podocarpi on Podocarpus grayae, Paraphysalospora eucalypti (incl. Paraphysalospora gen. nov.) on Eucalyptus sieberi, Pararamichloridium livistonae (incl. Pararamichloridium gen. nov., Pararamichloridiaceae fam. nov. and Pararamichloridiales ord. nov.) on Livistona sp., Pestalotiopsis dianellae on Dianella sp., Phaeosphaeria gahniae on Gahnia aspera, Phlogicylindrium tereticornis on Eucalyptus tereticornis, Pleopassalora acaciae on Acacia obliquinervia, Pseudodactylaria xanthorrhoeae (incl. Pseudodactylaria gen. nov., Pseudodactylariaceae fam. nov. and Pseudodactylariales ord. nov.) on Xanthorrhoea sp., Pseudosporidesmium lambertiae (incl. Pseudosporidesmiaceae fam. nov.) on Lambertia formosa, Saccharata acaciae on Acacia sp., Saccharata epacridis on Epacris sp., Saccharata hakeigena on Hakea sericea, Seiridium persooniae on Persoonia sp., Semifissispora tooloomensis on Eucalyptus dunnii, Stagonospora lomandrae on Lomandra longifolia, Stagonospora victoriana on Poaceae, Subramaniomyces podocarpi on Podocarpus elatus, Sympoventuria melaleucae on Melaleuca sp., Sympoventuria regnans on Eucalyptus regnans, Trichomerium eucalypti on Eucalyptus tereticornis, Vermiculariopsiella eucalypticola on Eucalyptus dalrympleana, Verrucoconiothyrium acaciae on Acacia falciformis, Xenopassalora petrophiles (incl. Xenopassalora gen. nov.) on Petrophile sp., Zasmidium dasypogonis on Dasypogon sp., Zasmidium gahniicola on Gahnia sieberiana. Brazil: Achaetomium lippiae on Lippia gracilis, Cyathus isometricus on decaying wood, Geastrum caririense on soil, Lycoperdon demoulinii (incl. Lycoperdon subg. Arenicola) on soil, Megatomentella cristata (incl. Megatomentella gen. nov.) on unidentified plant, Mutinus verrucosus on soil, Par...

Over the last two decades the molecular phylogeny and classification of Metarhizium has been widely studied. Despite these efforts to understand this enigmatic genus, the basal lineages in Metarhizium are still poorly resolved. In this study, a phylogenetic framework is reconstructed for the Clavicipitaceae focusing on Metarhizium through increased taxon-sampling using five genomic loci (SSU, LSU, tef, rpb1, rpb 2) and the barcode marker ITS rDNA. Multi-gene phylogenetic analyses and morphological characterisation of green-spored entomopathogenic Metarhizium isolates from Thailand and soil isolates of M. carneum and M. marquandii reveal their ecological, genetic and species diversity. Nineteen new species are recognised in the Metarhizium clade with narrow host ranges: two new species are found in the M. anisopliae complex – M. clavatum on Coleoptera larvae and M. sulphureum on Lepidoptera larvae; four new species are found in the M. flavoviride complex – M. biotecense and M. fusoideum on brown plant hoppers ( Hemiptera ), M. culicidarum on mosquitoes, M. nornnoi on Lepidoptera larvae; three new species M. megapomponiae, M. cicadae, M. niveum occur on cicadas; five new species M. candelabrum, M. cercopidarum, M. ellipsoideum, M. huainamdangense M. ovoidosporum occur on planthoppers, leafhoppers and froghoppers ( Hemiptera ); one new species M. eburneum on Lepidoptera pupae; and four new species M. phuwiangense, M. purpureum, M. purpureonigrum, M. flavum on Coleoptera . Of these 19 new species, seven produce a sexual morph ( M. clavatum, M. eburneum, M. flavum, M. phuwiangense, M. purpureonigrum, M. purpureum, and M. sulphureum ) and asexual morphs are found in the remaining new species and also in M. sulphureum, M. purpureonigrum and M. purpureum. Metarhizium blattodeae, M. koreanum and M. viridulum are new records for Thailand. An alternative neotype for Metarhizium anisopliae is proposed based on multi-gene and 5′ tef analyses showing that CBS 130.71 from Ukraine is more suitable, being from a much closer geographical location to Metchnikoff’s Metarhizium anisopliae. This isolate is distinct from the neotype of Metarhizium anisopliae var. anisopl...

Medical implants, like cardiovascular devices, improve the quality of life for countless individuals but may become infected with bacteria like Staphylococcus aureus. Such infections take the form of a biofilm, a structured community of bacterial cells adherent to the surface of a solid substrate. Every biofilm begins with an attractive force or bond between bacterium and substratum. We used atomic force microscopy to probe experimentally forces between a fibronectin-coated surface (i.e., proxy for an implanted cardiac device) and fibronectin-binding receptors on the surface of individual living bacteria from each of 80 clinical isolates of S. aureus. These isolates originated from humans with infected cardiac devices (CDI; n = 26), uninfected cardiac devices (n = 20), and the anterior nares of asymptomatic subjects (n = 34). CDI isolates exhibited a distinct bindingforce signature and had specific single amino acid polymorphisms in fibronectin-binding protein A corresponding to E652D, H782Q, and K786N. In silico molecular dynamics simulations demonstrate that residues D652, Q782, and N786 in fibronectin-binding protein A form extra hydrogen bonds with fibronectin, complementing the higher binding force and energy measured by atomic force microscopy for the CDI isolates. This study is significant, because it links pathogenic bacteria biofilms from the length scale of bonds acting across a nanometer-scale space to the clinical presentation of disease at the human dimension.adhesion | binding strength | host-pathogen interaction | pacemaker | prosthesis

Although it has recently been shown that A/J mice are highly susceptible to Staphylococcus aureus sepsis as compared to C57BL/6J, the specific genes responsible for this differential phenotype are unknown. Using chromosome substitution strains (CSS), we found that loci on chromosomes 8, 11, and 18 influence susceptibility to S. aureus sepsis in A/J mice. We then used two candidate gene selection strategies to identify genes on these three chromosomes associated with S. aureus susceptibility, and targeted genes identified by both gene selection strategies. First, we used whole genome transcription profiling to identify 191 (56 on chr. 8, 100 on chr. 11, and 35 on chr. 18) genes on our three chromosomes of interest that are differentially expressed between S. aureus-infected A/J and C57BL/6J. Second, we identified two significant quantitative trait loci (QTL) for survival post-infection on chr. 18 using N2 backcross mice (F1 [C18A]×C57BL/6J). Ten genes on chr. 18 (March3, Cep120, Chmp1b, Dcp2, Dtwd2, Isoc1, Lman1, Spire1, Tnfaip8, and Seh1l) mapped to the two significant QTL regions and were also identified by the expression array selection strategy. Using real-time PCR, 6 of these 10 genes (Chmp1b, Dtwd2, Isoc1, Lman1, Tnfaip8, and Seh1l) showed significantly different expression levels between S. aureus-infected A/J and C57BL/6J. For two (Tnfaip8 and Seh1l) of these 6 genes, siRNA-mediated knockdown of gene expression in S. aureus–challenged RAW264.7 macrophages induced significant changes in the cytokine response (IL-1 β and GM-CSF) compared to negative controls. These cytokine response changes were consistent with those seen in S. aureus-challenged peritoneal macrophages from CSS 18 mice (which contain A/J chromosome 18 but are otherwise C57BL/6J), but not C57BL/6J mice. These findings suggest that two genes, Tnfaip8 and Seh1l, may contribute to susceptibility to S. aureus in A/J mice, and represent promising candidates for human genetic susceptibility studies.

Background: Cardiovascular implants can become infected with Staphylococcus aureus. Results: Receptor proteins on S. aureus form a multivalent cluster bond with fibronectin, a human protein that coats implants. Conclusion: A more resilient bond is associated with infections observed in vivo. Significance: Normal microbial flora could be screened prior to surgery to determine risk in patients receiving cardiovascular implants.

Staphylococcus aureus is a leading cause of catheter infections, and biofilm formation plays a key role in the pathogenesis. Metal ion chelators inhibit bacterial biofilm formation and viability, making them attractive candidates as components in catheter lock solutions. The goal of this study was to characterize further the effect of chelators on biofilm formation. The effect of the calcium chelators ethylene glycol tetraacetic acid (EGTA) and trisodium citrate (TSC) on biofilm formation by 30 S. aureus strains was tested. The response to subinhibitory doses of EGTA and TSC varied dramatically depending on strain variation. In some strains, the chelators prevented biofilm formation, in others they had no effect, and they actually enhanced biofilm formation in others. The molecular basis for this phenotypic variability was investigated using two related strains: Newman, in which biofilm formation was inhibited by chelators, and 10833, which formed strong biofilms in the presence of chelators. It was found that deletion of the gene encoding the surface adhesin clumping factor B (clfB) completely eliminated chelator-induced biofilm formation in strain 10833. The role of ClfB in biofilm formation activity in chelators was confirmed in additional strains. It was concluded that biofilm-forming ability varies strikingly depending on strain background, and that ClfB is involved in biofilm formation in the presence EGTA and citrate. These results suggest that subinhibitory doses of chelating agents in catheter lock solutions may actually augment biofilm formation in certain strains of S. aureus, and emphasize the importance of using these agents appropriately so that inhibitory doses are achieved consistently.

The incidence of infections caused by antimicrobial-resistant Enterobacteriaceae in Thailand is increasing and human intestinal flora is an important reservoir for these organisms. This study was carried out to determine the intestinal carriage of bla extended spectrum ß-lactamase-positive Enterobacteriaceae (ESBL + E) and AmpC-positive Enterobacteriaceae in a community setting in Northern Thailand, and to identify potential risk factors for carriage. A total of 307 fecal samples were collected from healthy volunteers in Phitsanulok province, and cefotaxime-resistant Enterobacteriaceae (CtxRE) were isolated using selective media. Polymerase chain reaction (PCR) was used to detect ESBL and AmpC genes. Risk factors were analyzed using multiple logistic regression. Genotyping was performed by multilocus sequence typing (MLST) analysis. Two hundred ninety-one CtxRE isolates were obtained and Escherichia coli was the predominant organism (66.3%). The intestinal carriage rates of bla ESBL + E and AmpC-positive Enterobacteriaceae were 52.1% and 6.2%, respectively. Comparative levels of bla and bla were found while bla was the predominant genotype among AmpC genes. Co-existence of two ß-lactamase genes in a single isolate was found in 6.5% of isolates. Consumption of undercooked meat was strongly associated with intestinal carriage of bla ESBL + E (p = 0.003, OR = 2.133, 95% CI = 1.289-3.530). Phylogenetic grouping and MLST analysis of E. coli isolates revealed the presence of E. coli B2-ST131 (n = 8). Of these, seven carried bla and 1 carried bla. Our results suggest that residents in Thailand are at high risk for developing endogenous infections caused by antibiotic-resistant Enterobacteriaceae.