Assessment of plasmids for relating the 2020 Salmonella enterica serovar Newport onion outbreak to farms implicated by the outbreak investigation.

BACKGROUND: The Salmonella enterica serovar Newport red onion outbreak of 2020 was the largest foodborne outbreak of Salmonella in over a decade. The epidemiological investigation suggested two farms as the likely source of contamination. However, single nucleotide polymorphism (SNP) analysis of the whole genome sequencing data showed that none of the Salmonella isolates collected from the farm regions were linked to the clinical isolates-preventing the use of phylogenetics in source identification. Here, we explored an alternative method for analyzing the whole genome sequencing data driven by the hypothesis that if the outbreak strain had come from the farm regions, then the clinical isolates would disproportionately contain plasmids found in isolates from the farm regions due to horizontal transfer. RESULTS: SNP analysis confirmed that the clinical isolates formed a single, nearly-clonal clade with evidence for ancestry in California going back a decade. The clinical clade had a large core genome (4,399 genes) and a large and sparsely distributed accessory genome (2,577 genes, at least 64% on plasmids). At least 20 plasmid types occurred in the clinical clade, more than were found in the literature for Salmonella Newport. A small number of plasmids, 14 from 13 clinical isolates and 17 from 8 farm isolates, were found to be highly similar (> 95% identical)-indicating they might be related by horizontal transfer. Phylogenetic analysis was unable to determine the geographic origin, isolation source, or time of transfer of the plasmids, likely due to their promiscuous and transient nature. However, our resampling analysis suggested that observing a similar number and combination of highly similar plasmids in random samples of environmental Salmonella enterica within the NCBI Pathogen Detection database was unlikely, supporting a connection between the outbreak strain and the farms implicated by the epidemiological investigation. CONCLUSION: Horizontally transferred plasmids provided evidence for a connection between clinical isolates and the farms implicated as the source of the outbreak. Our case study suggests that such analyses might add a new dimension to source tracking investigations, but highlights the need for detailed and accurate metadata, more extensive environmental sampling, and a better understanding of plasmid molecular evolution.

Trabajar en salud durante la pandemia: Experiencias de vinculación con la comunidad relativas a la producción social del cuidado en Mar del Plata, Argentina / Work in health during the pandemic: Experiences of linking with the community related to the social production of care in Mar del Plata, Argentina

Resumen En este artículo proponemos visibilizar las estrategias de vinculación comunitaria de trabajadores/as de salud pública relativas a la producción del cuidado en el contexto crítico de la pandemia de la covid-19, signado por la profundización de la pobreza, la restricción de los servicios de salud y las tensiones del sistema sanitario en Argentina. Con un diseño metodológico cualitativo y enfoque etnográfico, entrevistamos a trabajadoras/es de distintas disciplinas, ocupaciones y géneros que se desempeñan en centros de salud y hospitales públicos en Mar del Plata y zonas rurales circundantes, entre los meses de marzo y diciembre de 2021. A partir de sus narrativas, analizamos las dimensiones de acceso a la alimentación, medicación y terapias holísticas, las dificultades encontradas y su contribución a la producción social del cuidado en salud. Concluimos que las estrategias generadas conllevan el potencial instituyente para la reorientación de los servicios públicos de salud de acuerdo con los desafíos del derecho a la salud desde la perspectiva de género y derechos en el tránsito a la postpandemia.

Abstract In this article we propose to make visible the strategies of community engagement of public health workers related to the production of care in the critical context of the covid-19 pandemic, marked by the deepening of poverty, the restriction of health services and the tensions of the health system in Argentina. With a qualitative methodological design and ethnographic approach, we interviewed workers from different disciplines, occupations and genders, who work in health centers and public hospitals in Mar del Plata and surrounding rural areas, between the months of March and December 2021. Based on their narratives, we analyze the dimensions of access to food, medication and holistic therapies, the difficulties encountered and their contribution to the social production of health care. We conclude that the strategies generated carry the instituting potential for the reorientation of public health services in accordance with the challenges of the right to health from the perspective of gender and rights in the transition to the post-pandemic.