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At least 19 recordsLinked to original sources

PubMed2026

Development of a Blockchain-Based Platform to Enable Indigenous Data Sovereignty and Shared Research Participation With Indigenous Communities: Technology Prototyping and Community Engagement Study.

BACKGROUND: Historic and ongoing problematic practices regarding the collection, storage, and use of Indigenous health data have led to the need to ensure principles of Indigenous Data Sovereignty (IDS) are followed in research practices and technology development. OBJECTIVE: This project, a partnership between UC San Diego and the Native BioData Consortium (NativeBio), sought to explore the practical application of blockchain technology and its potential to facilitate Indigenous-led research collaboration. METHODS: This project first undertook purposeful relationship building with NativeBio to form a Community Advisory Board (CAB) for identifying community and technology needs for a blockchain research collaboration platform with an initial focus on genomic data. Over a 2-year project period, a series of public meetings and presentations at Indigenous-led conferences introduced the concept of exploring compatibility between blockchain and IDS principles, followed by iterative prototyping and co-design of a blockchain platform with NativeBio, using Ethereum as the underlying protocol. RESULTS: Direct engagement with NativeBio and the CAB informed the initial design and development of a "b-IDS" proof-of-concept (POC) blockchain platform. The POC consists of three main components: (1) the web front-end layer, (2) the Ethereum network that executes the smart contract and blockchain storage aspects of the framework, and (3) the back-end database that stores off-chain interactions and data for future use with external genomic data repositories. After refinement of the POC, a community-based participatory research (CBPR) use case aligned with IDS principles was identified as a practical workflow and incorporated into the design of the POC for implementation. CONCLUSIONS: The findings from this project demonstrated the potential use of operationalizing IDS through blockchain technology with proactive and sustained engagement with Indigenous partners. Blockchain technology may have certain advantages over other data governance approaches and systems, facilitating timely oversight, shared decision-making and consent structures, and direct involvement of Indigenous communities in technology design, respecting the core principles of IDS and CBPR. Future development of the blockchain-IDS POC will need to incorporate other research practices and ethics frameworks to expand its use to other public health and biomedical research use cases.

Blockchain↗

PubMed2024

Tobacco, nicotine, and cannabis use and exposure in an Australian Indigenous population during pregnancy: A protocol to measure parental and foetal exposure and outcomes.

BACKGROUND: The Australian National Perinatal Data Collection collates all live and stillbirths from States and Territories in Australia. In that database, maternal cigarette smoking is noted twice (smoking <20 weeks gestation; smoking >20 weeks gestation). Cannabis use and other forms of nicotine use, for example vaping and nicotine replacement therapy, are nor reported. The 2021 report shows the rate of smoking for Australian Indigenous mothers was 42% compared with 11% for Australian non-Indigenous mothers. Evidence shows that Indigenous babies exposed to maternal smoking have a higher rate of adverse outcomes compared to non-Indigenous babies exposed to maternal smoking (S1 File). OBJECTIVES: The reasons for the differences in health outcome between Indigenous and non-Indigenous pregnancies exposed to tobacco and nicotine is unknown but will be explored in this project through a number of activities. Firstly, the patterns of parental and household tobacco, nicotine and cannabis use and exposure will be mapped during pregnancy. Secondly, a range of biological samples will be collected to enable the first determination of Australian Indigenous people's nicotine and cannabis metabolism during pregnancy; this assessment will be informed by pharmacogenomic analysis. Thirdly, the pharmacokinetic and pharmacogenomic findings will be considered against maternal, placental, foetal and neonatal outcomes. Lastly, an assessment of population health literacy and risk perception related to tobacco, nicotine and cannabis products peri-pregnancy will be undertaken. METHODS: This is a community-driven, co-designed, prospective, mixed-method observational study with regional Queensland parents expecting an Australian Indigenous baby and their close house-hold contacts during the peri-gestational period. The research utilises a multi-pronged and multi-disciplinary approach to explore interlinked objectives. RESULTS: A sample of 80 mothers expecting an Australian Indigenous baby will be recruited. This sample size will allow estimation of at least 90% sensitivity and specificity for the screening tool which maps the patterns of tobacco and nicotine use and exposure versus urinary cotinine with 95% CI within ±7% of the point estimate. The sample size required for other aspects of the research is less (pharmacokinetic and genomic n = 50, and the placental aspects n = 40), however from all 80 mothers, all samples will be collected. CONCLUSIONS: Results will be reported using the STROBE guidelines for observational studies. FORWARD: We acknowledge the Traditional Custodians, the Butchulla people, of the lands and waters upon which this research is conducted. We acknowledge their continuing connections to country and pay our respects to Elders past, present and emerging. Notation: In this document, the terms Aboriginal and Torres Strait Islander and Indigenous are used interchangeably for Australia's First Nations People. No disrespect is intended, and we acknowledge the rich cultural diversity of the groups of peoples that are the Traditional Custodians of the land with which they identify and with whom they share a connection and ancestry.

Adult↗

PubMed1979

Translocation of certain indigenous bacteria from the gastrointestinal tract to the mesenteric lymph nodes and other organs in a gnotobiotic mouse model.

Viable bacteria were not cultured from the mesenteric lymph nodes, spleens, or livers of specific-pathogen-free (SPF) mice. Viable enteric bacteria, primarily indigenous Escherichia coli and lactobacilli, were present in the mesenteric lymph nodes of gnotobiotic mice inoculated intragastrically with the whole cecal microflora from SPF mice but not in the nodes of control SPF mice similarly inoculated. These indigenous E. coli also were cultured from the mesenteric lymph nodes of 96% of gnotobiotic mice monoassociated with E. coli but from none of the mesenteric lymph nodes of SPF mice inoculated with the E. coli. Furthermore, viable E. coli were detected in the mesenteric lymph nodes of these monoassociated gnotobiotes for as long as 112 days after inoculation. Indigenous Lactobacillus acidophilus also translocated to the mesenteric lymph nodes of gnotobiotic mice monoassociated with L. acidophilus. Apparently, there are mechanisms active in SPF mice inhibiting translocation of indigenous bacteria from the gastrointestinal tract to the mesenteric lymph nodes, spleens, and livers, whereas these mechanisms are either absent or reduced in gnotobiotic mice. Indigenous E. coli maintained higher population levels in the gastrointestinal tracts of the gnotobiotes compared with their population levels in SPF mice, suggesting that high bacterial population levels might promote translocation of certain bacteria from the gastrointestinal lumen to the mesenteric lymph nodes. Gnotobiotic and SPF mice, therefore, provide experimental models for determining the nature of the mechanisms operating to confine indigenous bacteria to the gastrointestinal tract in normal, healthy animals.

Animals↗

PubMed2026

Pharmacogenomic diversity in Amazonian Indigenous populations: implications for Berlin-Frankfurt-Münster acute lymphoblastic leukemia therapy.

PURPOSE: This study aimed to characterize pharmacogenomic variation in genes involved in the metabolism and transport of drugs used in Berlin-Frankfurt-Münster-based therapy in Amazonian Indigenous individuals and to compare allele frequencies with major continental populations. METHODS/PATIENTS: Whole-exome sequencing data previously generated from 64 healthy Indigenous individuals from 12 Amazonian ethnic groups were analyzed. A total of 120 genes associated with drugs used in Berlin-Frankfurt-Münster protocols were selected. Variants were annotated and filtered using bioinformatic quality-control criteria, and allele frequencies were compared with African, Admixed American, East Asian, European, and South Asian populations from the 1000 Genomes Project. Multidimensional scaling was used to assess population-level genetic similarity. RESULTS: After quality control, 648 variants were identified. Twenty-eight variants were observed exclusively in the Indigenous study population, including four nonsynonymous coding variants with moderate predicted impact. Significant allele-frequency differences were observed for ADA rs11555566, CBR3 rs881711, and CYP2B6 rs3745274; rs881711 and rs3745274 differed from all five reference populations. Multidimensional scaling showed a distinct Indigenous pharmacogenomic profile, with greater similarity to the Admixed American population. CONCLUSIONS: Amazonian Indigenous populations exhibit substantial pharmacogenomic diversity in genes relevant to Berlin-Frankfurt-Münster-based therapy. These findings identify candidate variants for functional and clinical validation and reinforce the importance of including underrepresented populations in pharmacogenomic research.

Acute lymphoblastic leukemia↗

PubMed2026

Indigenous body image amid rapid social and economic change: A reflexive thematic analysis of Wayuu narratives.

The Wayuu, Colombia's largest Indigenous group, are experiencing rapid social, economic, and technological change, including expanding internet access, educational opportunities, and increasing exposure to globalised media. Though the harmful effects of appearance-idealised media imagery on body image are well documented, indigenous body image research remains unevenly distributed across global contexts, with Latin American Indigenous communities particularly underrepresented. This study explored how Wayuu people understand and experience appearance ideals and body image in the context of expanding digital media exposure and rapid sociocultural and economic change. Five focus groups of up to 9 participants were conducted with 29 Wayuu participants (18-68 years; 23 women, 6 men). Using reflexive thematic analysis, three overarching themes were identified: (1) Intersecting sources of appearance pressure: encompassing influences from social media, Wayuu family expectations, and discrimination from non-Indigenous peers; (2) Negotiating and resisting appearance ideals: from body dissatisfaction and restrictive eating to affirmation of cultural identity as protection; and (3) The changing role of appearance in today's Wayuu culture: participants linked globalised appearance ideals to expanding educational opportunities, migration, digital connectivity, and broader socioeconomic transformations occurring within Wayuu territories. While exposure to global ideals fostered comparison and dissatisfaction, cultural pride and collective belonging appeared to buffer against internalised colonial values. Culturally grounded media literacy and education initiatives co-developed with Wayuu communities could foster critical reflection while strengthening heritage. These results highlight the need for decolonial, community-based approaches to body image research and intervention in Indigenous contexts.

Adolescent↗

PubMed2026

Spatially resolved multi-omics analysis of indigenous Bacillus-fortified high-temperature Daqu.

Layer-dependent patterns associated with indigenous Bacillus fortification on high-temperature Daqu remain unclear. Here, six indigenous functional Bacillus strains were combined to fortify Daqu at three inoculation levels (QH4, QH5, QH6), with non-fortified as the control (CK). Upper, middle, and lower shelf-layer samples were profiled by physicochemical measurements, volatilomics, organic acid analysis, untargeted metabolomics, 16S/ITS amplicon sequencing, and metagenomics. PERMANOVA showed significant effects of treatment, spatial layer, and their interaction on physicochemical, volatile, bacterial, and fungal profiles (P = 0.001). Among the three inoculation levels, QH5 showed the most balanced performance: QH5_M exhibited the highest observed mean peak temperature (63.3 °C; +4.5 °C relative to CK_M), and its group-mean temperature remained ≥ 60 °C for seven consecutive days. Multi-omics analyses indicated coordinated, non-linear, and layer-dependent differences associated with indigenous Bacillus fortification, with QH5_M showing the most pronounced combined thermal, pyrazine, substrate, microbial, and predicted functional profile. These findings indicate that moderate indigenous Bacillus fortification was associated with distinct layer-dependent thermal and flavor profiles and coordinated microbial, metabolic, and predicted functional differences.

Bacillus↗

PubMed2026

Genomic insights into local adaptation of indigenous chickens.

Indigenous chickens are an essential part of biodiversity and a vital protein resource to humans, yet global warming and environmental changes pose serious threats to their survival and productivity. Therefore, assessing population adaptive capacity under shifting environments is crucial for breeding resilient animals, and guiding conservation strategies. Here, we integrated ecological and whole-genome resequencing data from 1 022 chickens from 44 Chinese indigenous populations to reveal genomic signatures of local adaptation. From 87 agroclimatic variables, we identified eight dominant environmental factors including solar radiation, precipitation, diurnal temperature range, and five landcover variables (cropland areas, water areas, trees coverage, bare ground and shrubs coverage) that shape ecological niches of indigenous chickens. Landscape and comparative genomics analyses revealed both known and novel candidate genes, such as UNC80, PTPRO, NCOR2, CSF2RB, NXT2 and PALLD for the solar radiation, precipitation, diurnal temperature range, cropland areas, trees coverage and bare ground, respectively. Particularly, adaptive non-coding variants harbored in these genes exhibited spatial allelic changes across populations and acted as regulatory elements via chromatin accessibility and DNA methylation, influencing adaptation in a tissue-specific manner. Our findings underscore the rich genetic diversity of Chinese indigenous chickens and provide new insights into genomic mechanisms of local adaptation, offering valuable references for domestic animal breeding, conservation, and climate resilience.

Animals↗

PubMed2025

Nutrigenomics: A tool to unlock genetic potential of Nigerian indigenous goat breeds.

Nigerian indigenous goats represent a valuable genetic resource for meat and milk production. However, their productivity often falls below their genetic potential because of sub-optimal nutrition. Nutrigenomics offers a revolutionary approach to bridge this gap by exploring the interactions between nutrients and goat genes. This study explores how nutrigenomic tools can be used to identify gene variants associated with feed efficiency, meat quality, and milk production. Various technologies are designed to ensure the realization of genetic potential. Nutrigenomics is aimed at exploiting the noncoding section of an individual's genome, which is disregarded in traditional animal nutrient requirement assessment. Nutrigenomic technology has the potential to unlock the genetic potential of animals and essentially help to confront nutritional challenges and sub-optimal use of available feed resources, particularly in Nigerian indigenous goats, of which there is a dearth of information on their nutritional needs and requirements. This review discusses the potential of nutrigenomics to unlock the genetic potential of Nigerian indigenous goats. In addition, the review discusses the challenges and future directions of nutrigenomic research in Nigerian goats. By implementing nutrigenomic strategies, Nigerian goat production can be revolutionized, leading to increased productivity, improved product quality, and enhanced farmer livelihoods. It is hoped that this review will provide vital information to aid research into the nutrigenomics potential of unlocking the genetic potentials and reproductive performance of Nigerian indigenous goats through nutrition.

Animals↗

PubMed2025

The cost and cost trajectory of genome sequencing and bioinformatics analysis for Indigenous children with suspected rare diseases.

PURPOSE: Indigenous peoples are underrepresented in reference genome libraries. Consequently, rare disease diagnosis may require bespoke bioinformatics analyses of genome sequences. Establishing diagnostic cost is crucial to support policy development for equitable diagnosis of rare diseases. We estimated the cost and cost trajectory of diagnostic genome sequencing and bioinformatics for Indigenous participants with suspected rare diseases. METHODS: We conducted a microcosting study of Indigenous children and their families receiving genome sequencing through Canada's Silent Genomes Project. Invoice data informed the costs of genome sequencing. We conducted a time-and-motion study for bioinformatics analyses, including labor, computing, and data storage costs. RESULTS: With standard bioinformatics, costs ranged from C$3645 (SD: 455) for singletons to C$7402 (SD: 566) for trios. With advanced, bespoke bioinformatics, costs ranged from C$5344 (SD: 634) for singletons to C$9760 (SD: 822) for trios. Genome sequencing was a primary cost driver; however, sequencing costs decreased by 61% over 4 years. Bioinformatics costs ranged from 21.3% to 58.3% of the total costs. The time required for bioinformatics ranged from 71 hours to 215 hours for standard and advanced analyses, respectively. CONCLUSION: Genome sequencing costs decreased over time. Bioinformatics is a significant cost driver, particularly for bespoke analyses arising from nonrepresentative reference libraries.

Humans↗

PubMed2025

Whole methylomes reveal high-altitude-associated methylation at hypoxia and pigmentation genes in South American Indigenous populations.

High-altitude adaptation in Andean populations has traditionally been studied through the lens of genetic variation, with limited exploration of epigenetic mechanisms such as DNA methylation. Here, we present the first whole-methylome data comparing Indigenous populations residing in high-altitude regions of the Ecuadorian Andes to those in low-altitude Peruvian Amazon regions bordering the Andes. By leveraging whole-methylome sequencing rather than methylation arrays, we achieved an unprecedented resolution of epigenetic variation, revealing novel insights into altitude-associated adaptations. We identified significant differentially methylated regions in genes involved in hypoxia response and skin pigmentation that differ from patterns previously observed in high-altitude Tibetan individuals [Lin et al. (Genome-wide DNA methylation landscape of four Chinese populations and epigenetic variation linked to Tibetan high-altitude adaptation. Science China Life Sciences 2023;66:2354-69. https://doi.org/10.1007/s11427-022-2284-8.)]. Our findings highlight the influence that altitude-specific environmental pressures, such as hypoxia and ultraviolet radiation, can have on the epigenetic landscapes observed between human populations. Importantly, we uncovered unique regulatory methylation signatures in the hypoxia response pathways of Andean populations, underscoring a distinct epigenetic trajectory compared to other high-altitude groups. This study represents a step forward in understanding Indigenous American genomic plasticity and demonstrates the value of whole-methylome data over methylation arrays in capturing the complex interplay between epigenetics and the environment. These results support a new approach to studying altitude plasticity and underscore the critical role of epigenetics in shaping population-specific cellular responses in Indigenous communities.

UV response↗

PubMed1978

HLA--D typing with homozygous cells identified in an American indigenous isolate. I. Population studies.

Lymphocytes from six individuals homozygous for their HLA--A, --B, --C and --D loci belonging to an American indigenous group, the Warao, have been used as typing cells to detect HLA--D determinants in 121 donors from the same indigenous isolate and in 71 donors of mixed ethnic origin living in Venezuela. Two determinants responsible for strong proliferation in mixed lymphocyte cultures have thus been identified. Four HLA--A2, B5 cells (r values between 0l72 and 0.57) identify a determinant provisionally called LD5a showing a gene frequency of 0.30 among the Warao and of 0.09 among the population of mixed ethnic origin. The nearest B locus antigen to this new specificity among the Warao is HLA--B5 (r value = 0.20). A second determinant identified by two HLA--A2, B15 sisters (r values of 0.71) shows a gene frequency of 0.15 among the Warao and of 0.03 among the mixed population. The latter is related to Dw8 as shown by results of the VI and VII Histocompatibility Workshops, and is weakly associated (r value of 0.28) to HLA--B15 among the American indigenous population tested.

Epitopes↗

PubMed1976

Influence of the indigenous gastrointestinal microbial flora on duodenal Mg2+ -dependent and (Na+ + K+) -stimulated adenosine triphosphatase activities in mice.

Mg-dependent and (Na+ + K+)-stimulated adenosine triphosphatase (ATP-ase) activities were assayed in butanol extracts of duodenal tissue from germ-free, specific-pathogen-free, and ex-germfree mice associated with an indigenous microflora from specific-pathogen-free mice. In the germfree mice the levels of both ATPase activities were significantly higher than the levels in specific-pathogen-free mice. By contrast, the ex-germfree animals colonized by an entire indigenous microflora, the values fell to levels close to those for specific-pathogen-free animals. (Na+ + K+)-stimulated ATPase was not inhibited by ouabain in extracts from any of the three kinds of mice. These findings show that the indigenous microbial flora influences the intestinal ATPase activity of mice and, because of the connection between (Na+ + K+-stimulate ATPase and active transpoort, undoubtedly affects the process of absorption in the intestinal tract.

Adenosine Triphosphatases↗

PubMed2026

Comparative Analysis of Volatile Compounds, Amino Acids, Fatty Acids, and Lipidomic Profiles in Thigh Muscles of Commercial Arbor Acres (AA) Broilers and Indigenous Chengkou and Langshan Chickens.

Flavor-related compounds and nutritional components of chicken meat vary among different breeds, but comprehensive comparisons of these characteristics between commercial and indigenous chickens remain insufficiently characterized. In this study, three chicken breeds (Arbor Acres, Chengkou, and Langshan) were slaughtered at their respective market ages, and the volatile flavor compounds, amino acids, fatty acids, and lipidomic profiles of thigh muscle were analyzed to investigate breed-associated differences in flavor-related and nutritional characteristics. Langshan chickens exhibited the highest total volatile compound content and also had the highest total amino acid levels, with significantly higher contents of umami and sweet amino acids. In addition, both indigenous breeds showed higher levels of arachidonic acid (C20:4n6) than Arbor Acres broilers, while Chengkou chickens had the highest content of docosahexaenoic acid (DHA, C22:6n3). Lipidomic analysis identified 787 lipids, with glycerophospholipids and sphingolipids as the predominant classes. Differential lipid analysis revealed that Langshan chickens had 38 upregulated lipids compared with Arbor Acres chickens, while Chengkou chickens exhibited 258 differential lipids relative to Arbor Acres chickens. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis indicated that these differential lipids were mainly associated with glycerolipid, sphingolipid, and glycerophospholipid metabolism. Correlation analysis further revealed significant associations between specific lipids and flavor-related compounds, amino acids, and fatty acids, suggesting their potential roles in breed-associated differences. Overall, this study demonstrates that indigenous chicken breeds possess distinct flavor-related and nutritional profiles compared with commercial Arbor Acres broilers and provides valuable insights into breed-associated differences in chicken meat characteristics.

amino acids↗

PubMed2026

Genetic Diversity and Population Structure of Zambian Indigenous Cattle.

A study was conducted to determine the genetic diversity of Zambian indigenous cattle using microsatellites. In Zambia, cattle provide draft power, food, manure and generate income. DNA extraction followed the Qiagen protocol, and Arlequin V3.0 was used for data analysis. 72 unrelated animals from three regions, Eastern (Angoni), Southern (Tonga) and Western (Barotse), were sampled. 315 alleles observed were higher in TGLA 263 (106 bp) with 0.861, 0.824 and 0.753, BMS650 (160 bp) with 0.710 and SPS 115 (248 bp) with 0.581, 0.710 and 0.794 for Angoni, Tonga and Barotse, respectively. Effective allele frequency was 4.521 ± 0.351, 4.246 ± 0.299 and 3.888 ± 0.289 for Angoni, Tonga and Barotse, respectively. Global deficit of heterozygotes across populations (Fit) amounted to 4.2%. Overall mean deficit of heterozygotes (Fis = 1%), genetic differentiation among breeds (Fst = 3.2%),, and genetic flow between populations (Nm = 11.3) ranged from RM 067 (40.564) to BLI (3.016). Analysis of molecular variance revealed 2.7% genetic variation among populations and 97.3% within the cattle population, with a mean genetic diversity of 0.753. Structure analysis (PCoA) demonstrated the presence of two subpopulations in which all three populations are represented and these two groups showed evidence of substructuring. In the Bayesian analysis, Tonga and Barotse populations were clustered together, while the Angoni were separated from the rest of the populations in K = 2. There was no evidence of panmixia and linkage equilibrium; the VD (9.153) value is greater than L (5.929), indicating that the population was in equilibrium. This study presents a comprehensive genetic characterisation of indigenous cattle in Zambia, which is important for further studies.

Animals↗

PubMed2026

Indigenous and local knowledge inclusion in forest fauna research: A systematic review in the tropics.

Indigenous and Local Knowledge (ILK) is an expression of biocultural diversity and is vital for inclusive and sustainable forest management and epistemic justice. We examine how researchers studying tropical forest fauna engage with ILK and the Indigenous Peoples and Local Communities (IPLC) who are holders of this knowledge. We conducted a systematic review of 62 articles that focus on tropical forest fauna and ILK. We used a category-based quantitative and qualitative content analysis on the types of forest fauna studied and how research engages with, defines and represents ILK. We also evaluated the varied forms of inclusion of IPLC in the research. We find that less than half of the reviewed studies (25) explicitly define ILK, and only four studies reported including IPLC in the decision-making processes. Our findings reveal that science has not fully acknowledged and understood the depth of ILK and we suggest ways to address this in future research.

Forests↗

PubMed2025

Multi-strain carriage and intrahost diversity of Staphylococcus aureus among Indigenous adults in the USA.

Staphylococcus aureus (SA) is an opportunistic pathogen and human commensal that is frequently present in the upper respiratory tract, gastrointestinal tract and skin. While SA can cause diseases ranging from minor skin infections to life-threatening bacteraemia, it can also be carried asymptomatically. Indigenous individuals in the Southwest USA experience high rates of invasive SA disease. As carriage is the most significant risk factor for disease, understanding the dynamics of SA carriage, and in particular co-carriage of multiple strains, is important to develop strategies to prevent transmission in vulnerable communities. Here, we investigated SA co-carriage and intrahost evolution by sampling several colonies from multiple anatomical sites and whole-genome sequencing (WGS) on 310 SA isolates collected from 60 Indigenous adults participating in a cross-sectional carriage study. We assessed the richness and diversity of SA isolates via differences in multilocus sequence type, core-genome SNPs and genome content. Using WGS data, we identified 95 distinct SA intra-subject lineages (ISLs) among 60 participants; co-carriage was detected in 42% (25/60). Notably, two participants each carried four distinct SA ISLs. Variation in antibiotic resistance determinants among carried strains was identified among 42% (25/60) of participants. Lastly, we found unequal distribution of clonal complex by body site, suggesting that certain lineages may be adapted to specific anatomical sites. Together, these findings suggest that co-carriage may occur more frequently than previously appreciated and further our understanding of SA intrahost diversity during carriage, which has implications for surveillance activities and epidemiological investigations.

Humans↗

PubMed1978

Intestinal enzyme activities in germfree, conventional, and gnotobiotic rats associated with indigenous microorganisms.

Various enzyme activities involved in the active transport system, glycolysis, and digestion were assayed in various parts of the gastrointestinal tracts of germfree, conventional, and gnotobiotic rats associated with indigenous bacteria. The activity levels of alkaline phosphatase, glucose 6-phosphatase, adenosine triphosphatase, and disaccharidases in the upper small intestine were highest in all parts of the gastrointestinal tracts of various kinds of gnotobiotic, conventional, and germfree rats. Alkaline phosphatase, glucose 6-phosphatase, and adenosine triphosphatase activities in the upper small intestine of germfree rats were, respectively, 2.3-, 2.9-, and 1.7-fold higher than those in conventional rats. Similar to the results of these enzymes, sucrase, maltase, trehalase, and lactase activities in the upper small intestine of germfree rats were, respectively, 1.6-, 1.5-, 2.3-, and 1.8-fold higher than those in conventional rats. In various gnotobiotic rats, enzyme activity levels were intermediate between those in germfree and conventional rats. These findings suggest that those enzymatic activities are strongly depressed by the association with the indigenous microorganisms in the epithelial mucosa of the upper small intestine of rats. The levels of pyruvate kinase, hexokinase, and lactate dehydrogenase activities were highest, respectively, in the stomach, cecum, and the upper small intestine and cecum in all parts of the gastrointestinal tracts in various kinds of gnotobiotic, conventional, and germfree rats. It was also shown that six kinds of gastrointestinal bacteria, including lactobacilli, significantly depressed the enzyme activity levels to levels between those of the germfree and conventional rats in the upper small intestine of gnotobiotic rats.

Adenosine Triphosphatases↗

PubMed1979

Models for study of the specificity by which indigenous lactobacilli adhere to murine gastric epithelia.

A Lactobacillus strain isolated from a mouse (indigenous) and another strain isolated from swine feces (nonindigenous) were compared in two model systems for their ability to adhere in vitro and in vivo to keratinizing squamous and columnar epithelia of mouse stomachs. In one model, stomachs dissected from specific-pathogen-free or germfree mice were injected with suspensions of lactobacilli labeled with [(3)H]thymidine and incubated at 37 degrees C. Thereafter, the non-secreting and secreting tissues were separated and washed vigorously. The radioactivity remaining with each tissue was counted by liquid scintillation spectrometry. When the radioactivity remaining with these tissues ranged between 500 and 100,000 cpm, the calculated radioactivity (disintegrations per minute) was related linearly to the number of lactobacilli adhering to the tissue. The estimate of the number of bacteria adherent to the tissue was not influenced significantly by artifacts in the techniques used. In this model, both Lactobacillus strains adhered in equally high numbers to both types of epithelial surfaces from stomachs from germfree mice. In contrast, in the second model, in which germfree mice were monoassociated with one or the other of the Lactobacillus strains, only the strain indigenous to the mouse formed dense layers on the epithelia of the nonsecreting portions of the stomachs, although both strains maintained high population levels throughout the gastrointestinal tracts of the animals. The capacity to adhere to the mucosal surface is undoubtedly necessary for lactobacilli to colonize gastric epithelia in mice. Our findings suggest, however, that nutritional or environmental conditions dictate whether particular Lactobacillus strains can colonize particular surfaces in the stomachs of living animals.

Animals↗