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The Clinical and Laboratory Standards Institute has published epidemiological cut-off values for susceptibility data generated at 22°°C and read after 44-48 h for florfenicol, oxolinic acid and oxytetracycline against Aeromonas salmonicida. The cut-off values for the minimum inhibitory concentration (MIC) and disc diffusion were derived from data obtained by 1 laboratory and 2 laboratories respectively. The present work reports the generation of susceptibility data from additional laboratories and the calculation of provisional cut-off values from aggregations of these data with previously published data. With respect to MIC data, the provisional cut-off values, derived from aggregations of the data from 4 laboratories, were ≤4 µg ml-1 for florfenicol, ≤0.0625 µg ml-1 for oxolinic acid and ≤1 µg ml-1 for oxytetracycline. For disc diffusion data, the provisional cut-off values derived from aggregations of the data from 5 laboratories were ≥30 mm for florfenicol, ≥32 mm for oxolinic acid and ≥25 mm for oxytetracycline. In addition, a cut-off value of ≥29 mm for ampicillin was derived from the aggregation of data from 4 laboratories.

N-methylated tryptamines, such as the hallucinogenic natural products, psilocybin and N,N-dimethyltryptamine (DMT), are gaining interest from the medical community due to their potential as next generation treatments for mental health disorders. The clinical relevance of these compounds has driven scientists to develop biosynthetic production routes to a number of tryptamine drug candidates, and efforts are ongoing to expand and further develop these biosynthetic capabilities. To that end, we have further characterized the substrate preferences of two enzymes involved in tryptamine biosynthesis: TrpM, a tryptophan N-methyltransferase from Psilocybe serbica, and PsiD, the gateway decarboxylase of the psilocybin biosynthesis pathway. Here, we show that TrpM can N-methylate the non-native amino acid substrate, 4-hydroxytryptophan, a key intermediate in the Escherichia coli-based recombinant psilocybin biosynthesis pathway. However, the ability to incorporate TrpM into a functional psilocybin biosynthesis pathway was thwarted by PsiD's inability to use N,N-dimethyl-4-hydroxytryptophan as substrate, under the culturing conditions tested, despite demonstrating activity on N-methylated and 4-hydroxylated tryptophan derivatives individually. Taken together, this work expands upon the known substrates for TrpM and PsiD, further increasing the diversity of tryptamine biosynthetic products., (© 2024 The Author(s). Biotechnology Progress published by Wiley Periodicals LLC on behalf of American Institute of Chemical Engineers.)

Purpose: Native Americans and Latinos have higher COVID-19 infection and mortality rates and may have limited access to diagnostic testing. Home-based testing may improve access to care in rural and underserved populations. This study tests the effect of community health worker (CHW) support on accessibility, feasibility, and completion of COVID-19 home testing among Native American and Latino adults living on the Flathead Reservation in Montana and in Yakima Valley, Washington., Methods: A two-arm, multisite, pragmatic randomized controlled trial was conducted using block randomization stratified by site and participant age. Active arm participants received CHW assistance with online COVID-19 test kit registration and virtual swabbing support. The passive arm participants received standard-of-care support from the kit vendor. Logistic regression modeled the association between study arm and test completion (primary outcome) and between study arm and test completion with return of valid test results (secondary outcome). Responses to posttest surveys and interviews were summarized using deductive thematic analysis., Findings: Overall, 63% of participants (n = 268) completed COVID-19 tests, and 50% completed tests yielding a valid result. Active arm participants had higher odds of test completion (odds ratio: 1.66, 95% confidence interval [1.01, 2.75]). Differences were most pronounced among adults ≥60 years. Participants cited ease of use and not having to leave home as positive aspects, and transportation and mailing issues as negative aspects of home-based testing., Conclusions: CHW support led to higher COVID-19 test completion rates, particularly among older adults. Significant testing barriers included language, educational level, rurality, and test kit issues., (© 2024 The Authors. The Journal of Rural Health published by Wiley Periodicals LLC on behalf of National Rural Health Association.)

Fibre-optic based time-resolved fluorescence spectroscopy (TRFS) is an advanced spectroscopy technique that generates sample-specific spectral-temporal signature, characterising variations in fluorescence in real-time. As such, it can be used to interrogate tissue autofluorescence. Recent advancements in TRFS technology, including the development of devices that simultaneously measure high-resolution spectral and temporal fluorescence, paired with novel analysis methods extracting information from these multidimensional measurements effectively, provide additional insight into the underlying autofluorescence features of a sample. This study demonstrates, using both simulated data and endogenous fluorophores measured bench-side, that the shape of the spectral fluorescence lifetime , or fluorescence lifetimes estimated over high-resolution spectral channels across a broad range, is influenced by the relative abundance of underlying fluorophores in mixed systems and their respective environment. This study, furthermore, explores the properties of the spectral fluorescence lifetime in paired lung tissue deemed either abnormal or normal by pathologists. We observe that, on average, the shape of the spectral fluorescence lifetime at multiple locations sampled on 14 abnormal lung tissue, compared to multiple locations sampled on the respective paired normal lung tissue, shows more variability; and, while not statistically significant, the average spectral fluorescence lifetime in abnormal tissue is consistently lower over every wavelength than the normal tissue., Competing Interests: The authors declare no conflicts of interest., (© 2024 The Author(s).)