Production of Fusaric Acid by Fusarium spp. in Pure Culture and in Solid Medium Co-Cultures.

The ability of fungi isolated from nails of patients suffering from onychomycosis to induce de novo production of bioactive compounds in co-culture was examined. Comparison between the metabolite profiles produced by Sarocladium strictum, by Fusarium oxysporum, and by these two species in co-culture revealed de novo induction of fusaric acid based on HRMS. Structure confirmation of this toxin, using sensitive microflow NMR, required only three 9-cm Petri dishes of fungal culture. A targeted metabolomics study based on UHPLC-HRMS confirmed that the production of fusaric acid was strain-dependent. Furthermore, the detected toxin levels suggested that onychomycosis-associated fungal strains of the F. oxysporum and F. fujikuroi species complexes are much more frequently producing fusaric acid, and in higher amount, than strains of the F. solani species complex. Fusarium strains producing no significant amounts of this compound in pure culture, were shown to de novo produce that compound when grown in co-culture. The role of fusaric acid in fungal virulence and defense is discussed

Bradyrhizobium elkanii nod regulon: insights through genomic analysis

Abstract A successful symbiotic relationship between soybean [Glycine max (L.) Merr.] and Bradyrhizobium species requires expression of the bacterial structural nod genes that encode for the synthesis of lipochitooligosaccharide nodulation signal molecules, known as Nod factors (NFs). Bradyrhizobium diazoefficiens USDA 110 possesses a wide nodulation gene repertoire that allows NF assembly and modification, with transcription of the nodYABCSUIJnolMNOnodZ operon depending upon specific activators, i.e., products of regulatory nod genes that are responsive to signaling molecules such as flavonoid compounds exuded by host plant roots. Central to this regulatory circuit of nod gene expression are NodD proteins, members of the LysR-type regulator family. In this study, publicly available Bradyrhizobium elkanii sequenced genomes were compared with the closely related B. diazoefficiens USDA 110 reference genome to determine the similarities between those genomes, especially with regards to the nod operon and nod regulon. Bioinformatics analyses revealed a correlation between functional mechanisms and key elements that play an essential role in the regulation of nod gene expression. These analyses also revealed new genomic features that had not been clearly explored before, some of which were unique for some B. elkanii genomes

Phase Ib of Copanlisib in Combination with Ibrutinib in Recurrent/Refractory Primary CNS Lymphoma (PCNSL)

BACKGROUND: PCNSL is an aggressive primary brain tumor with median progression free survival (PFS) after upfront methotrexate-based chemotherapy of 2-3 years. Outcome and treatment options are poor for recurrent/refractory (r/r) disease. This trial combines the pan-PI3K inhibitor copanlisib with Ibrutinib in patients with r/r PCNSL. METHODS: Eligible patients had r/r PCNSL, age≥18, ECOG≤2, normal end-organ function, and an unrestricted number of CNS directed prior therapies. Ibrutinib was given orally daily; copanlisib intravenously on days 1, 8, and 15 of each 28-day cycle. RESULTS: Six patients have been enrolled so far and received copanlisib at 60 mg and ibrutinib at 560 mg. Median age was 68 (range 50-77); 3 were women. Median ECOG was 1 (0: 2, 1: 3, 2: 1). All had recurrent parenchymal disease. Three had additional cerebrospinal fluid (CSF) involvement. Two had received prior single-agent ibrutinib. Initially, no prophylactic antimicrobial treatment was required. PCP prophylaxis was made mandatory after one patient developed PCP pneumonia leading to a grade 5 lung infection. Four patients are still on trial and one withdrew due to personal choice. Two grade 4 adverse events were observed in 2 patients (LFT elevation, lymphopenia); four grade 3 events in 3 patients (rash, lymphopenia, LFT elevation). The most common toxicities at any grade were transient, infusion-related hyperglycemia and hypertension. No Aspergillus infections have been observed. Enrollment into the next dose level (copanlisib 60 mg, ibrutinib 840 mg) is ongoing. After a median follow-up of 180 days (range 46-249), all patients were evaluated for response with an overall response rate of 67% with 1 CR, 3 PR, 1 SD and 1 PD as best response. CONCLUSION: Treatment with copanlisib and ibrutinib in patients with PCNSL has manageable adverse events after initiation of mandatory PCP prophylaxis. Clinical response was seen in 67% of patients. Disclosures Grommes: Squipps: Speakers Bureau; Kite: Consultancy; BTG: Consultancy. OffLabel Disclosure: The combination of the BTK inhibitor ibrutinib and the pan PI3K inhibitor copanlisib in recurrent PCNSL will be discussed </jats:sec