Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

Mpox Illness Narratives: Stigmatising Care and Recovery During and After an Emergency Outbreak

In May 2022, a global outbreak of mpox (formerly monkeypox virus) affected thousands of mainly gay and bisexual men. Mpox is usually a time-limited illness that can involve fever, pain, and skin lesions, but may require hospitalisation. There is scant research into the firsthand experiences of people affected by mpox, including experiences of symptoms, healthcare, and recovery. This study considers the different illness narratives of people who experienced mpox in Australia in 2022. In-depth interviews and 6-month follow-up interviews were conducted with 16 people, including 13 people diagnosed with mpox and three close contacts. All participants were cisgender gay or bisexual men living in Australia. Participants’ accounts described minor to severe periods of sickness, negative and stigmatising experiences engaging with healthcare, and some participants experienced long-term effects on their sexual well-being and complications from mpox. The emergency outbreak context meant that mpox was highly distressing, making it difficult to manage and producing varying forms of disruption to everyday life. Mpox was narrated as disruptive in different ways: as a minor interruption to holiday plans, a prolonged period of poor health, or a biographically disruptive event prompting a re-evaluation of sexual values and health. This analysis demonstrates that an unfamiliar emergent disease outbreak related to sexual practices and sociality can reconfigure personal life and sexual well-being, suggesting a need to focus on providing quality patient care in outbreaks of mpox and other infectious diseases