Patient genetics is linked to chronic wound microbiome composition and healing.

The clinical importance of microbiomes to the chronicity of wounds is widely appreciated, yet little is understood about patient-specific processes shaping wound microbiome composition. Here, a two-cohort microbiome-genome wide association study is presented through which patient genomic loci associated with chronic wound microbiome diversity were identified. Further investigation revealed that alternative TLN2 and ZNF521 genotypes explained significant inter-patient variation in relative abundance of two key pathogens, Pseudomonas aeruginosa and Staphylococcus epidermidis. Wound diversity was lowest in Pseudomonas aeruginosa infected wounds, and decreasing wound diversity had a significant negative linear relationship with healing rate. In addition to microbiome characteristics, age, diabetic status, and genetic ancestry all significantly influenced healing. Using structural equation modeling to identify common variance among SNPs, six loci were sufficient to explain 53% of variation in wound microbiome diversity, which was a 10% increase over traditional multiple regression. Focusing on TLN2, genotype at rs8031916 explained expression differences of alternative transcripts that differ in inclusion of important focal adhesion binding domains. Such differences are hypothesized to relate to wound microbiomes and healing through effects on bacterial exploitation of focal adhesions and/or cellular migration. Related, other associated loci were functionally enriched, often with roles in cytoskeletal dynamics. This study, being the first to identify patient genetic determinants for wound microbiomes and healing, implicates genetic variation determining cellular adhesion phenotypes as important drivers of infection type. The identification of predictive biomarkers for chronic wound microbiomes may serve as risk factors and guide treatment by informing patient-specific tendencies of infection.

Microorganism Profiles of Penile Prosthesis Removed for Infection, Erosion, and Mechanical Malfunction Based on Next-Generation Sequencing.

BACKGROUND: Next-generation sequencing (NGS) is an emerging technology that may allow for more sensitive and sophisticated microbial testing of the microbiota of penile prostheses (PP). AIM: To describe the microorganism profiles of PP explanted for infection, erosion, and mechanical malfunction using NGS. METHODS: All patients who underwent PP removal by two physicians at two institutions were identified. Differences in alpha diversity (ie, number of species detected, species diversity across samples) and microbiome compositional profiles (Bray-Curtis community dissimilarities) across samples were assessed using ANOVA and PERMANOVA, respectively. OUTCOMES: Number of species detected, species diversity across samples, and microbiome compositional profiles. RESULTS: A total of 83 patients who underwent device removal for infection (n = 8, 10%), erosion (n = 5, 6%), and mechanical malfunction (n = 70, 84%) were included. When considering all devices, 56% (n = 48) of NGS and 29% (n = 24) of standard cultures resulted positive for presence of microorganisms. Culture only detected the most abundant NGS species in 62.5% (n = 5) of infected devices. Species richness and microbiome compositional profiles varied by surgical indication, but not by age, race, diabetes status, or implant duration. Most frequent organisms by surgical indication were Pseudomonas aeruginosa (infection), Staphylococcus epidermidis (erosion), and Escherichia coli (mechanical malfunction). The highest relative abundance organisms were P aeruginosa (infection), Corynebacterium jeikeium (erosion), and E coli (mechanical malfunction). CLINICAL IMPLICATIONS: Identifying microbiome profiles of PP removed for infection, erosion, and mechanical malfunction may guide the selection of peri-operative antibiotics and PP antibiotic coatings or hydrophilic dip solutions for each individual scenario. STRENGTHS AND LIMITATIONS: While this is the first study to utilize next-generation sequencing to evaluate penile prosthesis biofilm, the clinical significance of these findings has yet to be determined. A prospective, randomized trial aimed at evaluating the clinical significance of NGS in patients with PP infection is currently underway. CONCLUSION: NGS testing identified distinct microbiome profiles of PP removed for infection, erosion, and mechanical malfunction. Chung PH, Leong JY, Phillips CD, Henry GD. Microorganism Profiles of Penile Prosthesis Removed for Infection, Erosion, and Mechanical Malfunction Based on Next-Generation Sequencing. J Sex Med 2022;19:356-363.

Molecular testing with next-generation sequencing appears to identify biofilm on penile prostheses better than traditional cultures: The new gold standard?

INTRODUCTION: Traditional culture is the current standard-of-care to determine therapeutic antibiotics for patients suffering from penile prostheses (PP) infections. However, approximately 50% of PPs removed for infection are culture negative. Next-generation sequencing (NGS) compares DNA sequences to reference sequences with known microbial taxonomies to identify isolates and report relative abundances. We aim to compare the ability for standard culture and NGS techniques to identify microorganisms and biofilm composition on PPs. MATERIALS AND METHODS: Ninety-one PPs explanted for mechanical malfunction were included in this study. Devices removed for infection or erosion were excluded. During revision surgery, two specimens were collected and sent for culture testing at institutional laboratory and for NGS testing (MicroGenDx, Lubbock, TX, USA). Species' relative abundances, sample diversity and richness, and compositional differences among samples were analyzed. RESULTS: NGS had a higher rate of microbial detection (n = 72, 79.1%) compared to culture results (n = 3, 3.3%). Some of the bacteria identified using both methods were known prosthetic infectious pathogens, with NGS producing more isolates (mean: 11) than culture (mean: 1). Escherichia coli was the most abundant and most frequently occurring bacteria detected on NGS. Coagulase-negative Staphylococci were the most common bacteria detected on traditional culture. CONCLUSIONS: NGS appears to be beneficial in its thorough analysis of PP biofilm composition when compared to culture methods. We hope that further research will be able to demonstrate a clinical benefit of NGS in characterizing distinct microbiomes and biofilms of infected PP, which can aid in tailoring antimicrobial therapy and improving patient outcomes.

Temporal dynamics of relative abundances and bacterial succession in chronic wound communities.

Polymicrobial bacterial infection is an important factor contributing to wound chronicity. Consequently, clinicians frequently adopt a biofilm-based wound care approach, in which wounds are treated utilizing DNA sequencing information about microbial communities. While more successful than treatment not using community information, there is little information about temporal dynamics of wound communities and optimal approaches over the course of treatment. To characterize these dynamics, temporal analysis over three sampling points was conducted for 167 chronic wounds. Across sampling intervals, wound communities from the same patients changed in composition, and most commonly shared less than 50% of observed species. There was a significant relationship between community similarity and time between sampling. Classifying wounds into state types, we found that communities frequently transitioned from Pseudomonas or Staphylococcus dominated, into a highly variable state type. Although low abundance microbial species are typically disregarded due to uncertainty of biological importance, we found that 80% of wound microbiomes included common or dominant species at subsequent time points that were in low abundance in earlier samples. Moreover, these species were often those known to frequently infect wounds. Results document compositional shifts through the course of treatment and suggest that routine consideration of low abundance species may improve biofilm-based wound care. Moreover, findings indicate that integrating ecological modeling to understand wound microbiome succession may lead to more informed therapy.

Analysis of the Duodenal Microbiome in Autistic Individuals: Association With Carbohydrate Digestion.

OBJECTIVES: There is evidence that symptoms of maldigestion or malabsorption in autistic individuals are related to changes in the indigenous microbiota. Analysis of colonic bacteria has revealed microbial dysbiosis in children with autism; however, characteristics of the duodenal microbiome are not well described. In the present study the microbiome of the duodenal mucosa of subjects with autism was evaluated for dysbiosis, bacteria overgrowth, and microbiota associated with carbohydrate digestion. The relationship between the duodenal microbiome and disaccharidase activity was analyzed in biopsies from 21 autistic subjects and 19 children without autism. METHODS: Microbiota composition was determined by 16S ribosomal RNA gene sequencing, and disaccharidase activity via biochemical assays. RESULTS: Although subjects with autism had a higher frequency of constipation (P < 0.005), there was no difference in disaccharidase activity between groups. In addition, no differences in microbiome diversity (species richness and evenness) were observed. Bacteria belonging to the genus Burkholderia were more abundant in subjects with autism, whereas members of the genus Neisseria were less abundant. At the species level, a relative decrease in abundance of 2 Bacteroides species and Escherichia coli was found in autistic individuals. There was a positive correlation between the abundance of Clostridium species, and disaccharidase activity, in autistic individuals. CONCLUSIONS: There are a variety of changes at the genus and species level in duodenal microbiota in children with autism that could be influenced by carbohydrate malabsorption. These observations could be affected by variations in individual diets, but also may represent a more pervasive dysbiosis that results in metabolites that affect the behavior of autistic children.

Analysis of the chronic wound microbiota of 2,963 patients by 16S rDNA pyrosequencing.

The extent to which microorganisms impair wound healing is an ongoing controversy in the management of chronic wounds. Because the high diversity and extreme variability of the microbiota between individual chronic wounds lead to inconsistent findings in small cohort studies, evaluation of a large number of chronic wounds using identical sequencing and bioinformatics methods is necessary for clinicians to be able to select appropriate empiric therapies. In this study, we utilized 16S rDNA pyrosequencing to analyze the composition of the bacterial communities present in samples obtained from patients with chronic diabetic foot ulcers (N = 910), venous leg ulcers (N = 916), decubitus ulcers (N = 767), and nonhealing surgical wounds (N = 370). The wound samples contained a high proportion of Staphylococcus and Pseudomonas species in 63 and 25% of all wounds, respectively; however, a high prevalence of anaerobic bacteria and bacteria traditionally considered commensalistic was also observed. Our results suggest that neither patient demographics nor wound type influenced the bacterial composition of the chronic wound microbiome. Collectively, these findings indicate that empiric antibiotic selection need not be based on nor altered for wound type. Furthermore, the results provide a much clearer understanding of chronic wound microbiota in general; clinical application of this new knowledge over time may help in its translation to improved wound healing outcomes.

Multilocus phylogeography of a widespread savanna-woodland-adapted rodent reveals the influence of Pleistocene geomorphology and climate change in Africa's Zambezi region.

Understanding historical influences of climate and physiographic barriers in shaping patterns of biodiversity remains limited for many regions of the world. For mammals of continental Africa, phylogeographic studies, particularly for West African lineages, implicate both geographic barriers and climate oscillations in shaping small mammal diversity. In contrast, studies for southern African species have revealed conflicting phylogenetic patterns for how mammalian lineages respond to both climate change and geologic events such as river formation, especially during the Pleistocene. However, these studies were often biased by limited geographic sampling or exclusively focused on large-bodied taxa. We exploited the broad southern African distribution of a savanna-woodland-adapted African rodent, Gerbilliscus leucogaster (bushveld gerbil) and generated mitochondrial, autosomal and sex chromosome data to quantify regional signatures of climatic and vicariant biogeographic phenomena. Results indicate the most recent common ancestor for all G. leucogaster lineages occurred during the early Pleistocene. We documented six divergent mitochondrial lineages that diverged ~0.270-0.100 mya, each of which was geographically isolated during periods characterized by alterations to the course of the Zambezi River and its tributaries as well as regional 'megadroughts'. Results demonstrate the presence of a widespread lineage exhibiting demographic expansion ~0.065-0.035 mya, a time that coincides with savanna-woodland expansion across southern Africa. A multilocus autosomal perspective revealed the influence of the Kafue River as a current barrier to gene flow and regions of secondary contact among divergent mitochondrial lineages. Our results demonstrate the importance of both climatic fluctuations and physiographic vicariance in shaping the distribution of southern African biodiversity.

Timeframes of speciation, reticulation, and hybridization in the bulldog bat explained through phylogenetic analyses of all genetic transmission elements.

Phylogenetic comparisons of the different mammalian genetic transmission elements (mtDNA, X-, Y-, and autosomal DNA) is a powerful approach for understanding the process of speciation in nature. Through such comparisons the unique inheritance pathways of each genetic element and gender-biased processes can link genomic structure to the evolutionary process, especially among lineages which have recently diversified, in which genetic isolation may be incomplete. Bulldog bats of the genus Noctilio are an exemplar lineage, being a young clade, widely distributed, and exhibiting unique feeding ecologies. In addition, currently recognized species are paraphyletic with respect to the mtDNA gene tree and contain morphologically identifiable clades that exhibit mtDNA divergences as great as among many species. To test taxonomic hypotheses and understand the contribution of hybridization to the extant distribution of genetic diversity in Noctilio, we used phylogenetic, coalescent stochastic modeling, and divergence time estimates using sequence data from cytochrome-b, cytochrome c oxidase-I, zinc finger Y, and zinc finger X, as well as evolutionary reconstructions based on amplified fragment length polymorphisms (AFLPs) data. No evidence of ongoing hybridization between the two currently recognized species was identified. However, signatures of an ancient mtDNA capture were recovered in which an mtDNA lineage of one species was captured early in the noctilionid radiation. Among subspecific mtDNA clades, which were generally coincident with morphology and statistically definable as species, signatures of ongoing hybridization were observed in sex chromosome sequences and AFLP. Divergence dating of genetic elements corroborates the diversification of extant Noctilio beginning about 3 Ma, with ongoing hybridization between mitochondrial lineages separated by 2.5 myr. The timeframe of species' divergence within Noctilio supports the hypothesis that shifts in the dietary strategies of gleaning insects (N. albiventris) or fish (N. leporinus) are among the most rapid instances of dietary evolution observed in mammals. This study illustrates the complex evolutionary dynamics shaping gene pools in nature, how comparisons of genetic elements can serve for understanding species boundaries, and the complex considerations for accurate taxonomic assignment.

A Metagenomics Pipeline to Characterize Self-Collected Vaginal Microbiome Samples.

Vaginitis is a widespread issue for women worldwide, yet current diagnostic tools are lacking. Bacterial vaginosis (BV) is the most prevalent type of vaginitis, found in 10-50% of reproductive-aged women. Current diagnostic methods for BV rely on clinical criteria, microscopy, or the detection of a few microbes by qPCR. However, many vaginal infections lack a single etiological agent and are characterized by changes in the vaginal microbiome community structure (e.g., BV is defined as a loss of protective lactobacilli resulting in an overgrowth of anaerobic bacteria). Shotgun metagenomic sequencing provides a comprehensive view of all the organisms present in the vaginal microbiome (VMB), allowing for a better understanding of all potential etiologies. Here, we describe a robust VMB metagenomics sequencing test with a sensitivity of 93.1%, a specificity of 90%, a negative predictive value of 93.4%, and a positive predictive value of 89.6% certified by Clinical Laboratory Improvement Amendments (CLIA), the College of American Pathologist (CAP), and the Clinical Laboratory Evaluation Program (CLEP). We sequenced over 7000 human vaginal samples with this pipeline and described general findings and comparisons to US census data.

The genome sequence of the endemic Mexican common mustached Bat, Pteronotus mexicanus. Miller, 1902 [Mormoopidae; Pteronotus].

We describe here the first characterization of the genome of the bat Pteronotus mexicanus, an endemic species of Mexico, as part of the Mexican Bat Genome Project which focuses on the characterization and assembly of the genomes of endemic bats in Mexico. The genome was assembled from a liver tissue sample of an adult male from Jalisco, Mexico provided by the Texas Tech University Museum tissue collection. The assembled genome size was 1.9 Gb. The assembly of the genome was fitted in a framework of 110,533 scaffolds and 1,659,535 contigs. The ecological importance of bats such as P. mexicanus, and their diverse ecological roles, underscores the value of having complete genomes in addressing information gaps and facing challenges regarding their function in ecosystems and their conservation.