Identification and characterization of a small-molecule metallophore involved in lanthanide metabolism.

Many bacteria secrete metallophores, low-molecular-weight organic compounds that bind ions with high selectivity and affinity, in order to access essential metals from the environment. Previous work has elucidated the structures and biosynthetic machinery of metallophores specific for iron, zinc, nickel, molybdenum, and copper. No physiologically relevant lanthanide-binding metallophore has been discovered despite the knowledge that lanthanide metals (Ln) have been revealed to be essential cofactors for certain alcohol dehydrogenases across a diverse range of phyla. Here, we report the biosynthetic machinery, the structure, and the physiological relevance of a lanthanophore, methylolanthanin. The structure of methylolanthanin exhibits a unique 4-hydroxybenzoate moiety which has not previously been described in other metallophores. We find that production of methylolanthanin is required for normal levels of Ln accumulation in the methylotrophic bacterium Methylobacterium extorquens AM1, while overexpression of the molecule greatly increases bioaccumulation and adsorption. Our results provide a clearer understanding of how Ln-utilizing bacteria sense, scavenge, and store Ln; essential processes in the environment where Ln are poorly bioavailable. More broadly, the identification of this lanthanophore opens doors for study of how biosynthetic gene clusters are repurposed for additional functions and the complex relationship between metal homeostasis and fitness.

Engineering Terpene Production Pathways in Methylobacterium extorquens AM1.

Terpenes are diverse specialized metabolites naturally found within plants and have important roles in inter-species communication, adaptation and interaction with the environment. Their industrial applications span a broad range, including fragrances, flavors, cosmetics, natural colorants to agrochemicals and therapeutics, yet formal chemical synthesis is economically challenging due to structural complexities. Engineering terpene biosynthesis could represent an alternative in microbial biotechnological workhorses, such as Saccharomyces cerevisiae or Escherichi coli, utilizing sugars or complex media as feedstocks. Host species that metabolize renewable and affordable carbon sources may offer unique sustainable biotechnological alternatives. Methylotrophs are bacteria with the capacity to utilize one-carbon feedstocks, such as methanol or formate. They colonize the phyllosphere (above-ground area) of plants, and many accumulate abundant carotenoid pigments. Methylotrophs have the capacity to take up and use a subset of the rare earth elements known as lanthanides. These metals can enhance one-carbon (methylotrophic) metabolism. Here, we investigated whether manipulating the metabolism enables and enhances terpene production. A carotenoid-deficient mutant potentially liberates carbon, which may contribute to bioproduct accumulation. To test this hypothesis, terpene-producing bacterial strains regulated by two distinct promoters were generated. Wildtype Methylobacterium extorquens, ∆Meta1_3665, a methylotrophic mutant lacking the carotenoid pathway, and an E. coli strain were transformed with an exogenous terpene pathway and grown both in the presence and absence of lanthanides. The extraction, and the comparison of analytical profiles, provided evidence that engineered cultured M. extorquens under control of a native, inducible methylotrophic promoter can yield the sesquiterpene patchoulol when supplemented with lanthanide. In contrast, using a moderate-strength constitutive promoter failed to give production. We demonstrated colonization of the phyllosphere with the engineered strains, supporting the future engineering of selected species of the plant microbiome and with promising implications for the synthetic biology of small molecules.

Scalable and Consolidated Microbial Platform for Rare Earth Element Leaching and Recovery from Waste Sources.

Chemical methods for the extraction and refinement of technologically critical rare earth elements (REEs) are energy-intensive, hazardous, and environmentally destructive. Current biobased extraction systems rely on extremophilic organisms and generate many of the same detrimental effects as chemical methodologies. The mesophilic methylotrophic bacterium Methylobacterium extorquens AM1 was previously shown to grow using electronic waste by naturally acquiring REEs to power methanol metabolism. Here we show that growth using electronic waste as a sole REE source is scalable up to 10 L with consistent metal yields without the use of harsh acids or high temperatures. The addition of organic acids increases REE leaching in a nonspecific manner. REE-specific bioleaching can be engineered through the overproduction of REE-binding ligands (called lanthanophores) and pyrroloquinoline quinone. REE bioaccumulation increases with the leachate concentration and is highly specific. REEs are stored intracellularly in polyphosphate granules, and genetic engineering to eliminate exopolyphosphatase activity increases metal accumulation, confirming the link between phosphate metabolism and biological REE use. Finally, we report the innate ability of M. extorquens to grow using other complex REE sources, including pulverized smartphones, demonstrating the flexibility and potential for use as a recovery platform for these critical metals.

Carbohydrate nutrition associated with health of overwintering honey bees.

In temperate climates, honey bees rely on stored carbohydrates to sustain them throughout the winter. In nature, honey serves as the bees' source of carbohydrates, but when managed, beekeepers often harvest honey and replace it with cheaper, artificial feed. The effects of alternative carbohydrate sources on colony survival, strength, and individual bee metabolic health are poorly understood. We assessed the impacts of carbohydrate diets (honey, sucrose syrup, high-fructose corn syrup, and invert syrup) on colony winter survival, population size, and worker bee nutritional state (i.e., fat content and gene expression of overwintered bees and emerging callow bees). We observed a nonsignificant trend for greater survival and larger adult population size among colonies overwintered on honey compared to the artificial feeds, with colonies fed high-fructose corn syrup performing particularly poorly. These trends were mirrored in individual bee physiology, with bees from colonies fed honey having significantly larger fat bodies than those from colonies fed high-fructose corn syrup. For bees fed honey or sucrose, we also observed gene expression profiles consistent with a higher nutritional state, associated with physiologically younger individuals. That is, there was significantly higher expression of vitellogenin and insulin-like peptide 2 and lower expression of insulin-like peptide 1 and juvenile hormone acid methyltransferase in the brains of bees that consumed honey or sucrose syrup relative to those that consumed invert syrup or high-fructose corn syrup. These findings further our understanding of the physiological implications of carbohydrate nutrition in honey bees and have applied implications for colony management.

Combating the Nursing Shortage: Recruitment and Retention of Nephrology Nurses.

Nurses are a critical part of the health care system. Yet the nursing profession continually faces shortages in all specialties. Several causes and issues of concern related to the nursing shortage in nephrology are discussed, including the prevalence of kidney disease and its increasing number of associated comorbidities, which has also heightened the urgent need for nephrology nurses. Data have shown that the lack of nephrology nurses caring for patients with kidney disease impacts patient outcomes and nephrology nurse burnout. Strategies must be implemented to manage these growing needs that affect both patient outcomes and nurse staffing. This article aims to identify methods to combat the nursing shortage, promote recruitment and retention strategies for nephrology nurses, and discuss leadership issues related to the topic.

Enfermedades asintomáticas o diagnósticos incipientes / Asymptomatic diseases or early diagnoses

RESUMEN Introducción: Constituye hecho relevante en el ejercicio de la medicina, individual o poblacional, conocer precozmente la instauración de las enfermedades, y por ello se tratan de realizar los diagnósticos clínicos precozmente. Sin embargo, un grupo de enfermedades, infecciosas o no infecciosas, agudas o crónicas, se caracterizan por escasas manifestaciones clínicas, por lo que el conocimiento de su existencia es de vital importancia, por ejemplo, la hipertensión arterial o la diabetes mellitus, cuyas expresiones sintomáticas pueden aparecer tardíamente. En igual medida, la actual pandemia por SARS-CoV-2, ha proliferado rápidamente debido al gran número de personas infectadas que no expresan síntomas. Objetivo: Caracterizar aspectos clínicos relevantes sobre las enfermedades asintomáticas y la importancia de los diagnósticos clínicos o biotecnológicos incipientes, individuales y poblacionales. Métodos: Se realizaron búsquedas bibliográficas de los últimos cinco años en libros clásicos de Medicina Interna, se analizaron artículos publicados en revistas nacionales e internacionales, específicamente en revistas de alto impacto como Lancet y The New England Journal of Medicine. Se consideraron bases de datos de la Organización Mundial de la Salud, así como lo expuesto en Infomed; además se utilizó Google Académico, con los descriptores de interés al respecto. Conclusiones: Por el momento siempre serán parciales, pues se enfatiza en las recomendaciones de la Organización Mundial de la Salud sobre la actual pandemia, para la identificación y control del SARS-CoV-2; se acentúa en la importancia de los métodos clínicos y epidemiológicos, así como en el desarrollo de la biotecnología para el conocimiento de las enfermedades.

ABSTRACT Introduction: early detection of the onset of diseases constitutes a relevant fact in the practice of individual or population medicine that is why early clinical diagnoses are tried to be made. However, a group of infectious or non-infectious, acute or chronic clinical diseases are characterized by few clinical manifestations, for which knowledge of their existence is of vital importance, for example, arterial hypertension or diabetes mellitus, whose symptomatic expressions may appear late. To the same extent, the current SARS-CoV-2 pandemic has proliferated rapidly due to the large number of infected people who do not express symptoms. Objective: to characterize relevant clinical aspects of asymptomatic diseases and the importance of incipient, individual and population clinical or biotechnological diagnoses. Methods: bibliographic searches of the last five years were carried out in classic books on Internal Medicine, articles published in national and international journals were analyzed, specifically in high-impact journals such as the Lancet and The New England Journal of Medicine. Databases of the World Health Organization were considered, as well as what was exposed in Infomed; in addition, Google Scholar was used, with the descriptors of interest in this regard. Conclusions: conclusions will always be partial for the moment, since the recommendations of the World Health Organization for the identification and control of SARS-CoV-2 are emphasized; the importance of clinical and epidemiological methods is highlighted, as well as the development of biotechnology for the knowledge of diseases.

Nephrology Nursing Scope and Standards of Practice: Take Pride in Practice.

The Nephrology Nursing Scope and Standards of Practice, 9th Edition, published by the American Nephrology Nurses Association, defines the scope of nephrology nursing and provides standards of practice, standards of professional performance, and competencies for registered nurses and graduate-level prepared registered nurses (e.g., advanced practice registered nurses, clinical nurse specialists) in an approach consistent with the American Nurses Association's Nursing Scope and Standards of Practice, published in 2021. Discussions addressing respect, equity, inclusion, and social justice have been included in the 9th edition. A new section related to altered/crisis standards has been added to assist nephrology nurses in developing strategies for implementing those standards. The section on how to use the standards has been updated with forms that organizations can download and individualize. This article provides an overview of the scope, standards, competencies, and strategies for implementing them in clinical practice.

Employing methylotrophs for a green economy: one-carbon to fuel them all and through metabolism redesign them.

Microbial platforms are currently being optimized to revolutionize industrial energy production while mitigating shortages of global resources and food supplies. Here, we address recent advances to develop bacterial methylotrophic platforms as promising platforms enabling the reuse of products and materials (at their highest value) while reducing waste and pollution.

Aprendiendo de La Vida (Learning from Life): Development of a Radionovela to Promote Preventive Health Care Utilization among Indigenous Farmworkers from Mexico Living in California.

Mixtecs and Zapotecs, originating from the Oaxaca area in Mexico, are among the largest indigenous groups of workers in California. Many adults in this community only access the health care system when sick and as a last resort. This article describes the development of a radionovela to inform the community about the importance of preventive health care. It was developed following the Sabido Method. The methodology to develop a radionovela may be of interest to other public health practitioners who want to develop educational materials in an engaging format, especially for communities that rely on oral, not written information.

Use of a gentamicin-citrate lock leads to lower catheter-related bloodstream infection rates and reduced cost of care in hemodialysis patients.

INTRODUCTION: Central venous catheters (CVC) are a major contributor to infections in hemodialysis (HD) patients, leading to high morbidity and mortality. Gentamicin-citrate (GC) lock is used as standard of care at centers belonging to a mid-size dialysis organization. Four outpatient HD centers acquired by the organization continued to use heparin for catheter locks for a period of time before converting to the provider's standard of using GC lock. METHODS: In this retrospective observational study, we included patients receiving HD by CVC at these four centers. We report rates of CVC-related bloodstream infections (CVC-BSI) during the heparin lock and the GC lock periods; crude rate ratios and adjusted rate ratios using Cox survival analyses adjusting for potential confounders; microbiology patterns; safety signals (gentamicin resistance, hospitalizations and deaths); and financial impact on payer. FINDINGS: A total of 220 and 281 patients used tunneled CVCs, accounting for 25,245 and 44,550 catheter days in the heparin and the GC lock periods, respectively. CVC-BSI event rates were 66% lower in the GC lock period (CVC-BSI event rate: 0.20 per 1000 catheter-days) than the heparin lock period (rate: 0.59 per 1000 catheter days); rate ratio 0.34 (95% confidence interval (CI) 0.15-0.78, P = 0.01). In the fully adjusted multivariable Cox model, use of GC lock was associated with 70% reduction in CVC-BSI events (HR 0.30, 95% CI 0.12-0.72, P = 0.01). No increased risk of gentamicin resistance, hospitalizations, or death associated with use of GC lock were observed. Use of GC lock was associated with an estimated saving of $1533 (95% CI: $259-$4882) per patient per year. DISCUSSION: Use of GC lock led to significant reductions in CVC-BSIs with no signal for harm, and is associated with significant cost savings in dialysis care.

Gene products and processes contributing to lanthanide homeostasis and methanol metabolism in Methylorubrum extorquens AM1.

Lanthanide elements have been recently recognized as "new life metals" yet much remains unknown regarding lanthanide acquisition and homeostasis. In Methylorubrum extorquens AM1, the periplasmic lanthanide-dependent methanol dehydrogenase XoxF1 produces formaldehyde, which is lethal if allowed to accumulate. This property enabled a transposon mutagenesis study and growth studies to confirm novel gene products required for XoxF1 function. The identified genes encode an MxaD homolog, an ABC-type transporter, an aminopeptidase, a putative homospermidine synthase, and two genes of unknown function annotated as orf6 and orf7. Lanthanide transport and trafficking genes were also identified. Growth and lanthanide uptake were measured using strains lacking individual lanthanide transport cluster genes, and transmission electron microscopy was used to visualize lanthanide localization. We corroborated previous reports that a TonB-ABC transport system is required for lanthanide incorporation to the cytoplasm. However, cells were able to acclimate over time and bypass the requirement for the TonB outer membrane transporter to allow expression of xoxF1 and growth. Transcriptional reporter fusions show that excess lanthanides repress the gene encoding the TonB-receptor. Using growth studies along with energy dispersive X-ray spectroscopy and transmission electron microscopy, we demonstrate that lanthanides are stored as cytoplasmic inclusions that resemble polyphosphate granules.

Lanthanides in Methylotrophy.

Lanthanides were previously thought to be biologically inert owing to their low solubility; however, they have recently been shown to strongly impact the metabolism of methylotrophic bacteria. Leading efforts in this emergent field have demonstrated far-reaching impacts of lanthanide metabolism in biology; from the identification of novel roles of enzymes and pathways dependent on lanthanide-chemistry to the control of transcriptional regulatory networks to the modification of microbial community interactions. Even further, the recent discovery of lanthanide-dependent enzymes associated with multi-carbon metabolism in both methylotrophs and non-methylotrophs alike suggests that lanthanide biochemistry may be more widespread than initially thought. Current efforts aim to understand how lanthanide chemistry and lanthanide-dependent enzymes affect numerous ecosystems and metabolic functions. These efforts will likely have a profound impact on biotechnological processes involving methylotrophic communities and the biologically mediated recovery of these critical metals from a variety of waste streams while redefining our understanding of a fundamental set of metals in biology.

Providing Health Education to Mixtec Farmworkers in California via Workshops and Radio: A Feasibility Study.

Originating from one of the poorest areas in Mexico, Mixtecs are one of the largest indigenous groups of workers in California. Providing health education to this group is challenging because many do not speak English or Spanish, and indigenous languages are mainly oral, not written. We explored the feasibility of conveying health information through the radio and in promotora-led workshops. The study included an evaluation of the workshops through surveys before the workshop and 4 to 6 months later in a subsample of 96 indigenous women. The number of radio listeners averaged more than 2,000 per month, and 500 community members attended a workshop. Among women who completed pre- and postworkshop assessments (N = 75), there was a statistically significant increase in knowledge of how to get a wellness visit, where to get a free mammogram, and mammography screening guidelines. Women who ever had a mammogram or wellness visit at baseline were significantly more likely to report receipt of this service during the follow-up period than women who never had this service. Educational workshops and radio are promising and culturally appropriate strategies to provide health information in this community. However, many women need additional assistance to navigate access to health care.

Nephrology Nursing Scope and Standards of Practice: Integration into Clinical Practice.

The eighth edition of the Nephrology Nursing Scope and Standards of Practice, published by the American Nephrology Nurses Association (Gomez, 2017), defines the scope of nephrology nursing practice, and provides standards of practice and professional performance in an approach similar to the American Nurses Association (ANA) 2016 standards. ANNA's eighth edition of the Nephrology Nursing Scope and Standards of Practice incorporates competencies for graduate level-prepared nurses in addition to the registered nurse (RN) and advanced practice registered nurse (APRN). The section on how to use the standards in practice has been updated with user-friendly forms. This article provides an overview of the scope of practice, standards, competencies, and situations that require intervention by the nephrology nurse.

Lanthanide Chemistry: From Coordination in Chemical Complexes Shaping Our Technology to Coordination in Enzymes Shaping Bacterial Metabolism.

Lanthanide chemistry has only been extensively studied for the last 2 decades, when it was recognized that these elements have unusual chemical characteristics including fluorescent and potent magnetic properties because of their unique 4f electrons.1,2 Chemists are rapidly and efficiently integrating lanthanides into numerous compounds and materials for sophisticated applications. In fact, lanthanides are often referred to as "the seeds of technology" because they are essential for many technological devices including smartphones, computers, solar cells, batteries, wind turbines, lasers, and optical glasses.3-6 However, the effect of lanthanides on biological systems has been understudied. Although displacement of Ca2+ by lanthanides in tissues and enzymes has long been observed,7 only a few recent studies suggest a biological role for lanthanides based on their stimulatory properties toward some plants and bacteria.8,9 Also, it was not until 2011 that the first biochemical evidence for lanthanides as inherent metals in bacterial enzymes was published.10 This forum provides an overview of the classical and current aspects of lanthanide coordination chemistry employed in the development of technology along with the biological role of lanthanides in alcohol oxidation. The construction of lanthanide-organic frameworks will be described. Examples of how the luminescence field is rapidly evolving as more information about lanthanide-metal emissions is obtained will be highlighted, including biological imaging and telecommunications.11 Recent breakthroughs and observations from different exciting areas linked to the coordination chemistry of lanthanides that will be mentioned in this forum include the synthesis of (i) macrocyclic ligands, (ii) antenna molecules, (iii) coordination polymers, particularly nanoparticles, (iv) hybrid materials, and (v) lanthanide fuel cells. Further, the role of lanthanides in bacterial metabolism will be discussed, highlighting the discovery that lanthanides are cofactors in biology, particularly in the enzymatic oxidation of alcohols. Finally, new and developing chemical and biological lanthanide mining and recycling extraction processes will be introduced.

Large-Effect Beneficial Synonymous Mutations Mediate Rapid and Parallel Adaptation in a Bacterium.

Contrary to previous understanding, recent evidence indicates that synonymous codon changes may sometimes face strong selection. However, it remains difficult to generalize the nature, strength, and mechanism(s) of such selection. Previously, we showed that synonymous variants of a key enzyme-coding gene (fae) of Methylobacterium extorquens AM1 decreased enzyme production and reduced fitness dramatically. We now show that during laboratory evolution, these variants rapidly regained fitness via parallel yet variant-specific, highly beneficial point mutations in the N-terminal region of fae These mutations (including four synonymous mutations) had weak but consistently positive impacts on transcript levels, enzyme production, or enzyme activity. However, none of the proposed mechanisms (including internal ribosome pause sites or mRNA structure) predicted the fitness impact of evolved or additional, engineered point mutations. This study shows that synonymous mutations can be fixed through strong positive selection, but the mechanism for their benefit varies depending on the local sequence context.

Challenges facing nephrology nursing.

The health care system is in the midst of great change and nephrology nurses continually face challenges in their work environments. Nephrology nurses are well poised to meet these challenges by virtue of their numbers, scientific knowledge, and adaptive capacity, and providers would benefit from taking advantage of the contributions nurses can make.