Ratiometric pre-rRNA analysis (RPA) detects the replenishment of rRNA precursors that occurs rapidly upon nutritional stimulation of bacterial cells. In contrast to DNA detection by PCR, RPA distinguishes viable from inactivated bacteria. It exhibits promise as a molecular viability test for pathogens in water and other environmental samples.As a tool for detecting bacteria in environmental samples, the PCR is limited in part by the false-positive detection of nonviable bacteria and free DNA. One solution to this problem involves treating bacteria with DNA intercalators that penetrate inactivated cells and inhibit PCR amplification (15). These methods require careful titration, and performance varies with sample and disinfection conditions (8,16). An alternative is to detect microbial RNA, which is less stable than DNA in the environment (10-12, 14, 17-19, 23). However, mRNA can be difficult to detect, while mature rRNA is stable within inactivated cells.Microbial rRNA precursors (pre-rRNA) comprise an alternative RNA target (2-4, 11, 17, 23). Pre-rRNAs have leader and tail sequences that are enzymatically removed during rRNA maturation. Pre-rRNA sequences are phylogenetically specific, which facilitates their detection in complex samples. In growing bacterial cells, pre-rRNAs constitute a significant fraction of the total rRNA and are much easier to detect than mRNA. Upon cessation of growth, pre-rRNA synthesis ceases but maturation continues, draining pre-rRNA pools. PrerRNA has been used as a steady-state indicator of bacterial physiology (2, 11); however, this strategy is compromised by the complex interplay of pre-rRNA synthesis and processing (2).The present study exploited the replenishment of pre-rRNA that occurs immediately upon the nutritional stimulation of nutrient-limited bacterial cells. Species-specific pre-rRNA was measured in samples after brief exposure to culture medium. Values that exceeded those seen in nonstimulated control samples indicated the presence of viable cells. This ratiometric pre-rRNA analysis (RPA) approach was tested on the rapidly growing opportunistic pathogen Aeromonas hydrophila (generation time [g] ϭ 1 h) and the slowly growing actinomycete Mycobacterium avium (g ϭ 20 h).For both organisms, real-time quantitative PCRs (RTqPCRs) targeted the 5Ј pre-rRNA leader region. Primers were designed to straddle the 5Ј mature rRNA terminus. Primers for cDNA synthesis and reverse PCR primers recognized semiconserved sequences within the mature rRNA. Forward primers recognized predicted species-specific sequences within the 5Ј leader. Therefore, amplification required intact specific prerRNA as templates (see Table S1 in the supplemental material).Primers targeted to the M. avium complex (MAC) consistently yielded the expected amplification products when applied to 19 genotypically diverse isolates of M. avium subsp. hominissuis and M. intracellulare (1, 9), the two most significant human pathogens within the MAC. Nucleic acids from M. terrae, M. gastri, M. smegmatis, M. nonchromogenic...

Background: Traditional ecological knowledge (TEK) is a conceptual framework that highlights Indigenous knowledge (IK) systems. Although scientific literature has noted the relevance of TEK for environmental research since the 1980s, little attention has been given to how Native American (NA) scholars engage with it to shape tribal-based research on health, nor how non-Native scholars can coordinate their approaches with TEK. This coordination is of particular importance for environmental health sciences (EHS) research exploring interdisciplinary approaches and the integration of environmental and human health. Objective: Our perspective on TEK arose from a series of Health and Culture Research Group (HCRG) workshops that identified gaps in existing EHS methodologies that are based on a reliance on Euro-American concepts for assessing environmental exposures in tribal communities. These prior methods neither take into account cultural behavior nor community responses to these. Our objective is to consider NA perspectives on TEK when analyzing relationships between health and the environment and to look at how these may be applied to address this gap. Discussion: The authors—the majority of whom are NA scholars—highlight two research areas that consider health from a TEK perspective: food systems and knowledge of medicinal plants. This research has yielded data, methods, and knowledge that have helped Indigenous communities better define and reduce health risks and protect local natural food resources, and this TEK approach may prove of value to EHS research. Conclusion: NA perspectives on TEK resulting from the HCRG workshops provide an opportunity for developing more accurate Indigenous health indicators (IHI) reflecting the conceptualizations of health maintained in these communities. This approach has the potential to bridge the scientific study of exposure with methods addressing a tribal perspective on the sociocultural determinants of health, identifying potential new areas of inquiry in EHS that afford nuanced evaluations of exposures and outcomes in tribal communities. https://doi.org/10.1289/EHP1944

Tribal Institutional Review Boards (TIRBs) in the United States assert their rights within sovereign nations by developing ethical research processes that align with tribal values to protect indigenous knowledge systems and their community from cultural appropriation, exploitation, misuse, and harm. We reviewed six TIRB applications and processes to gain a better understanding about their requirements and research ethics. We located 48 activated and deactivated TIRBs in a database, mapped them in relation to tribal reservation lands, and then conducted in-depth content analysis. Our analysis demonstrates the importance of building relationships, becoming fully acquainted with the TIRB’s operating environment before seeking research approval, and issues related to tribal data management practices.

Community driven co-design models can help collaborators to respectfully engage in projects that provide much-needed resources and services to underserved communities. For example, partnerships between tribal, academic, and non-profit collaborators have the potential to generate positive outcomes for communities when individual efforts by those same groups may be less successful. However, cultural and spiritual differences between collaborators (particularly tribal and non-tribal) can lead to misunderstandings and negative project outcomes, despite good intentions and an honest effort by collaborators to achieve a common goal. Here, we provide a case study of a community-driven co-design project involving tribal, academic, and private collaborators to design and build a rainwater harvesting system with the Akiak Native Community (ANC), and their tribal council in Alaska, USA. A novel collaborative co-design process honoring the tribal sovereignty of the ANC is emphasized in this case study; a design model that is poorly represented in the literature with real-world examples. Logistics associated with designing and constructing the community-use rainwater harvesting system on Alaskan tribal lands is reviewed but the focus of this work is on the collaborative design process more so than the construction of the water harvesting system end product. More explicitly, the use of multiple approaches to promote collaborator involvement along with an emphasis on developing community driven project goals are highlighted as essential steps in our co-design process.

BACKGROUND: Tribal communities in the United States (U.S.) have a long history of subjection to unethical and exploitive medical and research practices. Today, many Tribal nations are establishing procedures in order to protect themselves from further harm and to advance culturally informed research practices. These procedures are also meant to ensure that their communities benefit from research conducted within their communities. Informed consent is a key element in protecting human subjects, but it may not be sufficient in the tribal context, as its conception is rooted in Western understandings of protection. Specifically, the informed consent emphasizes the individual, rather than the community as a whole, which is just as important in the context of conducting research with Native communities.METHODS: We conduct a systematic literature review to answer two related questions: How is informed consent being conceived of by U.S. tribes? And how is informed consent being required by U.S. tribes? Our inclusion criteria include articles focusing on informed consent within the U.S. tribal context, written in English in 2010-2020. Articles that did not fit our inclusion criteria were excluded. Two reviewers independently reviewed and coded 30 peer-reviewed articles by using content analysis and, in an iterative process, agreed on emerging codes and themes. RESULTS: A number of themes arise in the selected literature, including the conception of informed consent as a process, its operation at various levels (individual, collective, and government-to-government), possible alternatives to informed consent, and the need for specificity about ownership of samples and data, benefits and/or risks, and the methods and procedures that researchers use in the course of study.CONCLUSIONS: Our key results point to a need for clear and transparent information for prospective research participants and for consent forms and processes to include the collective, as well as the individual. This will better align with the cultural values and political standing of sovereign tribes in the U.S.