A Pseudoalteromonas Clade with Remarkable Biosynthetic Potential.

Pseudoalteromonas species produce a diverse range of biologically active compounds, including those biosynthesized by nonribosomal peptide synthetases (NRPSs) and polyketide synthases (PKSs). Here, we report the biochemical and genomic analysis of Pseudoalteromonas sp. strain HM-SA03, isolated from the blue-ringed octopus, Hapalochlaena sp. Genome mining for secondary metabolite pathways revealed seven putative NRPS/PKS biosynthesis gene clusters, including those for the biosynthesis of alterochromides, pseudoalterobactins, alteramides, and four novel compounds. Among these was a novel siderophore biosynthesis gene cluster with unprecedented architecture (NRPS-PKS-NRPS-PKS-NRPS-PKS-NRPS). Alterochromide production in HM-SA03 was also confirmed by liquid chromatography-mass spectrometry. An investigation of the biosynthetic potential of 42 publicly available Pseudoalteromonas genomes indicated that some of these gene clusters are distributed throughout the genus. Through the phylogenetic analysis, a particular subset of strains formed a clade with extraordinary biosynthetic potential, with an average density of 10 biosynthesis gene clusters per genome. In contrast, the majority of Pseudoalteromonas strains outside this clade contained an average of three clusters encoding complex biosynthesis. These results highlight the underexplored potential of Pseudoalteromonas as a source of new natural products.IMPORTANCE This study demonstrates that the Pseudoalteromonas strain HM-SA03, isolated from the venomous blue-ringed octopus, Hapalochalaena sp., is a biosynthetically talented organism, capable of producing alterochromides and potentially six other specialized metabolites. We identified a pseudoalterobactin biosynthesis gene cluster and proposed a pathway for the production of the associated siderophore. A novel siderophore biosynthesis gene cluster with unprecedented architecture was also identified in the HM-SA03 genome. Finally, we demonstrated that HM-SA03 belongs to a phylogenetic clade of strains with extraordinary biosynthetic potential. While our results do not support a role of HM-SA03 in Hapalochalaena sp. venom (tetrodotoxin) production, they emphasize the untapped potential of Pseudoalteromonas as a source of novel natural products.

Goals of care in the Wellington Emergency Department: a clinical audit.

AIMS: To determine how often goals of care (GOC) are being discussed with older patients in the emergency department (ED). METHODS: This clinical audit included 300 presentations of patients aged 80 years and over in the Wellington ED. The timeframe was from 1 July to 17 July 2021. Electronic records were interrogated for GOC discussions. RESULTS: Most older patients (62%) did not have a GOC discussion in the ED. Of patients over the age of 80 who had a GOC discussion in the emergency department, only 14% of those discussions were initiated by ED clinicians. CONCLUSIONS: There are no current standards for GOC within the ED and this should be established for further research. Protocols and education regarding facilitating GOC discussions in the ED could be established to improve the frequency of GOC discussions.

Genome mining of a fungal endophyte of Taxus yunnanensis (Chinese yew) leads to the discovery of a novel azaphilone polyketide, lijiquinone.

Genome mining of Ascomycete sp. F53 (F53), a fungal endophyte of the traditional Chinese medicinal plant Taxus yunnanensis (Chinese yew), revealed 35 putative specialized metabolite biosynthesis gene clusters, one of which encodes a rarely seen tandem polyketide synthase pathway with close homology to azaphilone biosynthesis pathways. A novel compound, lijiquinone 1, was subsequently isolated from F53 and structurally and functionally characterized. The m/z 385 [M + H+ ]+ compound, comprised of a cyclohexenone side group attached to a core bicyclic ring, displayed cytotoxicity against human myeloma cells (IC50  = 129 µM), as well as antifungal activity against Candida albicans (IC50  = 79 µM) and Cryptococcus albidus (IC50  = 141 µM). Our results suggest that enzymes encoded on the lij gene cluster are responsible for the synthesis of 1 and that the medicinal properties of T. yunnanensis could be partially mediated by this novel azaphilone. This study highlights the utility of combining traditional knowledge with contemporary genomic approaches for the discovery of new bioactive compounds.