Transgenerational phenotypic responses to herbicide stress are more rapid than to shade and simulated herbivory in Arabidopsis.

Weeds in agricultural settings continually adapt to stresses from ecological and anthropogenic sources, in some cases leading to resistant populations. However, consequences of repeated sub-lethal exposure of these stressors on fitness and stress "memory" over generations remain poorly understood. We measured plant performance over a transgenerational experiment with Arabidopsis thaliana where plants were exposed to sub-lethal stress induced by the herbicides glyphosate or trifloxysulfuron, stresses from clipping or shading in either one (G1) or four successive generations (G1-G4), and control plants that never received stress. We found that fourth-generation (G4) plants that had been subjected to three generations of glyphosate or trifloxysulfuron stress produced higher post-stress biomass, seed weight, and rosette area as compared to that produced by plants that experienced stress only in the first generation (G1). By the same measure, clipping and shade were more influential on floral development time (shade) and seed weight (clipping) but did not show responsive phenotypes for vegetative metrics after multiple generations. Overall, we found that plants exhibited more rapid transgenerational vegetative "stress memory" to herbicides while reproductive plasticity was stressor dependent and similar between clipping/shade and anthropogenic stressors. Our study suggests that maternal plant stress memory aids next-generation plants to respond and survive better under the same stressors.

Acute Respiratory Failure With a Rare, Rapidly Progressing Pediatric Desmoid Tumor Anterior Mediastinal Mass.

ABSTRACT: We present an unusual case of a 6-year-old boy who presented with the sudden presence of left neck mass and acute hypoxemic respiratory failure, whose subsequent imaging demonstrated a previously undiagnosed anterior mediastinal mass (AMM) extending into the left neck. Biopsy of the mass was consistent with a desmoid tumor, which is a rare cause of AMM in children. Desmoid tumors are locally aggressive, often invading and enveloping surrounding tissues, but overall slow growing. The sudden growth of the neck mass suggests a very aggressive desmoid tumor, causing an unexpected respiratory compromise. Anterior mediastinal masses may cause symptoms by compressing the heart, great vessels, and airways. However, the patient may adapt and develop compensatory mechanisms to counter the compressive effects. Emergency care of the patient with an AMM who presents with acute respiratory distress includes optimizing oxygenation through promoting a calm environment, oxygenating while minimizing positive end-expiratory pressure, maintaining the patient's compensatory mechanisms by minimizing sedation and muscle relaxation, positioning the patient to minimize compressive effects of the mass on the vital thorax structures, and early consultation with pediatric specialists to develop a shared-emergency treatment strategy and to secure an expedited disposition to the appropriate venue of care.

Suspension and expulsion in Colorado early care and education settings: Child, program, and community-level predictors.

Expulsion presents a significant risk in Early Care and Education (ECE) settings due to its association with early disadvantage and frequency of use. A statewide survey was conducted to characterize ECE suspension and expulsion (S/E) in Colorado. Child, program, and community-level factors were examined as predictors of S/E, alongside preventative intervention supports capable of reducing S/E. Six hundred and sixty three licensed child care programs participated in the survey, providing information on 19,848 enrolled children, 312 suspensions, and 74 expulsions. A series of multilevel hierarchical regressions were conducted, examining predictors for S/E. Children with IEPs/IFSPs were disproportionately suspended; 2-3-year-olds were disproportionately expelled; and boys, 5-6-year-olds, and children with disabilities were disproportionately suspended and expelled. Center-based programs, lower quality ratings, and "zero tolerance" policies predicted greater use of suspension. In contrast, school-district affiliation and knowledge of how to access infant and early childhood mental health consultation (IECMHC) decreased suspension. Lower levels of regional child poverty predicted higher use of expulsion. Affiliation with a school-district, IECMH consultant-led training, and use of quality coaches predicted decreased expulsion. This study identifies the need for ongoing protection for children with IEPs/ IFSPs and the preventative interventions that mitigate risk for S/E.

Introducción. La expulsión presenta un riesgo significativo en el marco del Temprano Cuidado y Educación (ECE) debido a su asociación con tempranas desventajas y la frecuencia de uso. Una encuesta a nivel estatal se llevó a cabo para caracterizar la suspensión y expulsión de ECE (S/E) en Colorado. Asuntos relacionados con el niño, el programa y de nivel comunitario se examinaron como factores de predicción de (S/E), junto con apoyos de intervención para prevenir, capaces de reducir S/E. Métodos. Participaron en la encuesta 663 programas de cuidado infantil autorizados, lo cual aportó información sobre 19,848 niños matriculados, 312 suspensiones y 74 expulsiones. Se llevó a cabo una serie de regresiones jerárquicas de niveles múltiples, examinando así los factores de predicción de S/E. Resultados. A los niños con participación en programas o planes IEP/IFSP se les suspendió de manera desproporcionada; niños entre los dos y tres años fueron desproporcionalmente expulsados; y varones de cinco a seis años, y niños con discapacidades fueron desproporcionalmente suspendidos y expulsados. Los programas con base en un centro, los más bajos puntajes de evaluación de la calidad y las políticas de 'tolerancia cero' predijeron el mayor uso de la suspensión. En contraste, la afiliación a un distrito escolar y el conocimiento de cómo tener acceso a la consulta de salud mental infantil y la temprana niñez (IECMHC) redujo las suspensiones. Los más bajos niveles de pobreza regional de niños predijeron el más alto uso de la expulsión. La afiliación a un distrito escolar, el entrenamiento de consultores de IECMH, así como el uso de entrenadores calificados predijeron una reducción de las expulsiones. Conclusiones. Este estudio identifica la necesidad de una continuada protección para niños en programas o planes IEP/IFSP y las intervenciones de prevención que mitigan el riesgo de S/E.

INTRODUCTION: L'expulsion présente un risque important pour les contextes de Soins Précoces et Education (en anglais Early Care and Education, abrégé ici ECE) du fait de son lien à un désavantage précoce et la fréquence de l'utilisation. Un sondage au niveau de l'état a été fait afin de caractériser la suspension ECE et l'expulsion (S/E) dans l'état du Colorado aux Etats-Unis. L'enfant, le programme et les facteurs aux niveau de la communauté ont été examinés en tant que facteurs de prédiction de la (S/E), en parallèle avec des soutiens d'une intervention préventive capable de réduire la S/E. Méthodes. 663 programmes de crèches accréditées ont participé au questionnaire, offrant des renseignements sur 19848 enfants inscrits, 312 suspensions et 74 expulsions. Une série de régressions hiérarchiques à niveaux multiples a été faite, examinant les facteurs de prédiction pour la S/E. Résultats. Les enfants avec des plans IEP/IFSP (Plan d'Enseignement Individualisé/Plan Individualisé de Service à la Famille) ont été suspendus de manière disproportionnée ; les enfants de deux à trois ans ont été expulsés de manière disproportionnée, et les enfants avec des handicaps ont été suspendus et expulsée de manière disproportionnée. Les programmes centres (centrés sur une condition), les cotes de qualité inférieure et les politiques de « zéro tolérance ¼ ont prédit une plus grande utilisation de la suspension. Par contre, l'affiliation à un district académique et des connaissances sur la manière d'accéder à la consultation de santé mentale du nourrisson et de la petite enfance (IECMHC) ont fait décroître le taux de suspension. Des niveaux plus bas de pauvreté de l'enfant régionale ont prédit une utilisation plus élevée de la suspension. L'affiliation à un district académique, la formation faite par un consultant IECMH et l'utilisation de formateurs de qualité ont prédit une expulsion moins élevée. Cette étude identifie le besoin de protection continue des enfants avec des plans IEP/IFSP et d'interventions préventives qui mitigent le risque de S/E.

Simultaneous isolation and label-free identification of bacteria using contactless dielectrophoresis and Raman spectroscopy.

The traditional bacterial identification method of growing colonies on agar plates can take several days to weeks to complete depending on the growth rate of the bacteria. Successfully decreasing this analysis time requires cell isolation followed by identification. One way to decrease analysis time is by combining dielectrophoresis (DEP), a common technique used for cell sorting and isolation, and Raman spectroscopy for cell identification. DEP-Raman devices have been used for bacterial analysis, however, these devices have a number of drawbacks including sample heating, cell-to-electrode proximity that limits throughput and separation efficiency, electrode fouling, or inability to address sample debris. Presented here is a contactless DEP-Raman device to simultaneously isolate and identify particles from a mixed sample while avoiding common drawbacks associated with other DEP designs. Using the device, a mixed sample of bacteria and 3 µm polystyrene spheres were isolated from each other and a Raman spectrum of the trapped bacteria was acquired, indicating the potential for cDEP-Raman devices to decrease the analysis time of bacteria.

Invasive plants negatively impact native, but not exotic, animals.

Despite our growing understanding of the impacts of invasive plants on ecosystem structure and function, important gaps remain, including whether native and exotic species respond differently to plant invasion. This would elucidate basic ecological interactions and inform management. We performed a meta-analytic review of the effects of invasive plants on native and exotic resident animals. We found that invasive plants reduced the abundance of native, but not exotic, animals. This varied by animal phyla, with invasive plants reducing the abundance of native annelids and chordates, but not mollusks or arthropods. We found dissimilar impacts among "wet" and "dry" ecosystems, but not among animal trophic levels. Additionally, the impact of invasive plants increased over time, but this did not vary with animal nativity. Our review found that no studies considered resident nativity differences, and most did not identify animals to species. We call for more rigorous studies of invaded community impacts across taxa, and most importantly, explicit consideration of resident biogeographic origin. We provide an important first insight into how native and exotic species respond differently to invasion, the consequences of which may facilitate cascading trophic disruptions further exacerbating global change consequences to ecosystem structure and function.

New pasture plants intensify invasive species risk.

Agricultural intensification is critical to meet global food demand, but intensification threatens native species and degrades ecosystems. Sustainable intensification (SI) is heralded as a new approach for enabling growth in agriculture while minimizing environmental impacts. However, the SI literature has overlooked a major environmental risk. Using data from eight countries on six continents, we show that few governments regulate conventionally bred pasture taxa to limit threats to natural areas, even though most agribusinesses promote taxa with substantial weed risk. New pasture taxa (including species, subspecies, varieties, cultivars, and plant-endophyte combinations) are bred with characteristics typical of invasive species and environmental weeds. By introducing novel genetic and endophyte variation, pasture taxa are imbued with additional capacity for invasion and environmental impact. New strategies to prevent future problems are urgently needed. We highlight opportunities for researchers, agribusiness, and consumers to reduce environmental risks associated with new pasture taxa. We also emphasize four main approaches that governments could consider as they build new policies to limit weed risks, including (i) national lists of taxa that are prohibited based on environmental risk; (ii) a weed risk assessment for all new taxa; (iii) a program to rapidly detect and control new taxa that invade natural areas; and (iv) the polluter-pays principle, so that if a taxon becomes an environmental weed, industry pays for its management. There is mounting pressure to increase livestock production. With foresight and planning, growth in agriculture can be achieved sustainably provided that the scope of SI expands to encompass environmental weed risks.

Elevated resting heart rate in heart transplant recipients: innocent bystander or adverse prognostic indicator?

BACKGROUND: The elevated baseline heart rate (HR) of a heart transplant recipient has previously been considered inconsequential. However, we hypothesized that a resting HR above 100 beats per minute (bpm) may be associated with morbidity and mortality. METHODS: The U.T.A.H. Cardiac Transplant Program studied patients who received a heart transplant between 2000 and 2011. Outpatient HR values for each patient were averaged during the first year post-transplant. The study cohort was divided into two groups: the tachycardic (TC) (HR > 100 bpm) and the non-TC group (HR ≤ 100 bpm) in which mortality, incidence of rejection, and cardiac allograft vasculopathy were compared. RESULTS: Three hundred and ten patients were included as follows: 73 in the TC and 237 in the non-TC group. The TC group had a higher risk of a 10-yr all-cause mortality (p = 0.004) and cardiovascular mortality (p = 0.044). After adjustment for donor and recipient characteristics in multivariable logistic regression analysis, the hazard ratio was 3.9, (p = 0.03, CI: 1.2-13.2) and 2.6 (p = 0.02, CI: 1.2-5.5) for cardiovascular mortality and all-cause mortality, respectively. CONCLUSION: Heart transplant recipients with elevated resting HR appear to have higher mortality than those with lower resting HR. Whether pharmacologically lowering the HR would result in better outcomes warrants further investigation.

Barbed versus standard sutures for closure in total knee arthroplasty: a multicenter prospective randomized trial.

Barbed suture has been associated with improved closure efficiency and safety in TKA in prior studies. We performed a multicenter randomized controlled trial to determine the efficiency and safety of this technology in TKA. We prospectively randomized 411 patients undergoing primary TKA to either barbed running (n=191) or knotted interrupted suture closure (n=203). Closure time was measured intra-operatively. Cost analysis was based on suture and OR time costs. Closure time was shorter with barbed suture (9.8 vs. 14.5 min, p<0.001). Total closure cost was less with barbed suture ($324 vs. $419, p<0.001). Early complications and outcomes were similar between groups. The use of barbed suture in TKA is associated with shorter closure time, lower cost and similar outcomes and complications when compared with standard sutures.

Implications of germination tolerances on invasion potential of Arthraxon hispidus.

Arthraxon hispidus is an introduced, rapidly spreading, and newly invasive grass in the eastern United States, yet little is known about the foundational biology of this aggressive invader. Germination responses to environmental factors including salinity, pH, osmotic potential, temperature, and burial depth were investigated to better understand its germination niche. Seeds from six populations in the Mid-Atlantic US germinated 95% with an average mean time to germination of 3.42 days of imbibition in the dark at 23°C. Germination occurred across a temperature range of 8-37°C and a pH range of 5-10 (≥83%), suggesting that neither pH nor temperature will limit germination in many environments. Arthraxon hispidus germination occurred in high salinity (342 mM NaCl) and osmotic potentials as low as -0.83MPa. The NaCl concentration required to reduce germination by 50% exceeded salinity concentrations found in soil and some brackish water saltmarsh systems. While drought adversely affects A. hispidus, 50% germination occurred at osmotic potentials ranging from -0.25 to -0.67 MPa. Given the climatic conditions of North America, drought stress is unlikely to restrict germination in large regions. Finally, emergence greatly decreased with burial depth. Emergence was reduced to 45% at 1-2 cm burial depths, and 0% at 8 cm. Emergence depths in concert with adequate moisture, germination across a range of temperatures, and rapid germination suggests A. hispidus' seed bank may be short-lived in moist environments, but further investigation is warranted. Given the broad abiotic tolerances of A. hispidus and a widespread native range, A. hispidus has the potential to germinate in novel territories beyond its currently observed invaded range.

Adaptive constraints at the range edge of a widespread and expanding invasive plant.

Identifying the factors that facilitate and limit invasive species' range expansion has both practical and theoretical importance, especially at the range edges. Here, we used reciprocal common garden experiments spanning the North/South and East/West range that include the North American core, intermediate and range edges of the globally invasive plant, Johnsongrass (Sorghum halepense) to investigate the interplay of climate, biotic interactions (i.e. competition) and patterns of adaptation. Our results suggest that the rapid range expansion of Johnsongrass into diverse environments across wide geographies occurred largely without local adaptation, but that further range expansion may be restricted by a fitness trade-off that limits population growth at the range edge. Interestingly, plant competition strongly dampened Johnsongrass growth but did not change the rank order performance of populations within a garden, though this varied among gardens (climates). Our findings highlight the importance of including the range edge when studying the range dynamics of invasive species, especially as we try to understand how invasive species will respond to accelerating global changes.

WHIPPET: a novel tool for prioritizing invasive plant populations for regional eradication.

Large geographic areas can have numerous incipient invasive plant populations that necessitate eradication. However, resources are often deficient to address every infestation. Within the United States, weed lists (either state-level or smaller unit) generally guide the prioritization of eradication of each listed species uniformly across the focus region. This strategy has several limitations that can compromise overall effectiveness, which include spending limited resources on 1) low impact populations, 2) difficult to access populations, or 3) missing high impact populations of low priority species. Therefore, we developed a novel science-based, transparent, analytical ranking tool to prioritize weed populations, instead of species, for eradication and tested it on a group of noxious weeds in California. For outreach purposes, we named the tool WHIPPET (Weed Heuristics: Invasive Population Prioritization for Eradication Tool). Using the Analytic Hierarchy Process that included expert opinion, we developed three major criteria, four sub-criteria, and four sub-sub-criteria, taking into account both species and population characteristics. Subject matter experts weighted and scored these criteria to assess the relative impact, potential spread, and feasibility of eradication (major criteria) for 100 total populations of 19 species. Species-wide population scores indicated that conspecific populations do not necessarily group together in the final ranked output. Thus, priority lists based solely on species-level characteristics are less effective compared to a blended prioritization based on both species attributes and individual population and site parameters. WHIPPET should facilitate a more efficacious decision-making process allocating limited resources to target invasive plant infestations with the greatest predicted impacts to the region under consideration.

Into the weeds: new insights in plant stress.

Weeds, plants that thrive in the face of disturbance, have eluded human's attempts at control for >12 000 years, positioning them as a unique group of extreme stress tolerators. The most successful weeds have a suite of traits that enable them to rapidly adapt to environments typified by stress, growing in hostile conditions or subject to massive destruction from agricultural practices. Through their ability to persist and adapt, weeds illuminate principles of evolution and provide insights into weed management and crop improvement. Here we highlight why the time is right to move beyond traditional model systems and leverage weeds to gain a deeper understanding of the mechanisms, adaptations, and genetic and physiological bases for stress tolerance.

Habitat Suitability and Establishment Limitations of a Problematic Liana.

The US native liana, poison ivy (Toxicodendron radicans), responsible for contact dermatitis in humans, is a competitive weed with great potential for expansion in disturbed habitats. To facilitate a better understanding of this threat, we sought to evaluate habitat suitability, population demography, and biotic interactions of poison ivy, using a series of complementary field studies in the two habitats where it most commonly occurs-forest interiors and edges. Of the 2500 seeds planted across both habitats, poison ivy initially colonized forest interiors (32% emergence) at a higher rate than edge habitats (16.5% emergence). However, forest interior seedlings were less likely to survive (interior n = 3; edge n = 15), which might be attributed to herbivore pressure when the seedlings were smaller in the less competitive forest interior. Once established, the poison ivy seedlings appeared to be more tolerant of herbivory, except that of large grazers such as deer. The early life stage of seedling emergence, survival, and establishment are critical in poison ivy success, with biotic pressure, especially from plant competition and deer, limiting recruitment. A suitable habitat of this expanding native liana would increase with increasing forest fragmentation, but might be buffered by the expanding deer population.

Horsenettle (Solanum carolinense) fruit bacterial communities are not variable across fine spatial scales.

Fruit house microbial communities that are unique from the rest of the plant. While symbiotic microbial communities complete important functions for their hosts, the fruit microbiome is often understudied compared to other plant organs. Fruits are reproductive tissues that house, protect, and facilitate the dispersal of seeds, and thus they are directly tied to plant fitness. Fruit microbial communities may, therefore, also impact plant fitness. In this study, we assessed how bacterial communities associated with fruit of Solanum carolinense, a native herbaceous perennial weed, vary at fine spatial scales (<0.5 km). A majority of the studies conducted on plant microbial communities have been done at large spatial scales and have observed microbial community variation across these large spatial scales. However, both the environment and pollinators play a role in shaping plant microbial communities and likely have impacts on the plant microbiome at fine scales. We collected fruit samples from eight sampling locations, ranging from 2 to 450 m apart, and assessed the fruit bacterial communities using 16S rRNA gene amplicon sequencing. Overall, we found no differences in observed richness or microbial community composition among sampling locations. Bacterial community structure of fruits collected near one another were not more different than those that were farther apart at the scales we examined. These fine spatial scales are important to obligate out-crossing plant species such as S. carolinense because they are ecologically relevant to pollinators. Thus, our results could imply that pollinators serve to homogenize fruit bacterial communities across these smaller scales.

Home climate and habitat drive ecotypic stress response differences in an invasive grass.

Invasive plants and agricultural weeds are a ubiquitous and ever-expanding threat to biosecurity, biodiversity and ecosystem services. Many of these species are known to succeed through rapid adaptation to biotic and abiotic stress regimes, often in highly disturbed systems. Given the current state of evidence for selection of weedy genotypes via primary physiological stresses like drought, flooding, heat, cold and nutrient deficiency, we posit that adaptation to land management regimes which comprise suites of these stresses can also be expected. To establish this link, we tested adaptation to water and nutrient stresses in five non-agricultural and five agricultural populations of the invader Johnsongrass (Sorghum halepense) sampled across a broad range of climates in the USA. We subjected seedlings from each population to factorial drought and nutrient stresses in a common garden greenhouse experiment. Agricultural and non-agricultural ecotypes did not respond differently to experimentally applied stresses. However, non-agricultural populations from more drought-prone and nutrient-poor locations outperformed their agricultural counterparts in shoot allocation and chlorophyll production, respectively. We also found evidence for root allocation adaptation to hotter climates, in line with other C4 grasses, while greater adaptation to drought treatment was associated with soil organic carbon (SOC)-rich habitats. These findings imply that adaptation to land-use types can interact with other macrohabitat parameters, which will be fluctuating in a changing climate and resource-needy world. We see that invasive plants are poised to take on novel habitats within their introduced ranges, leading to complications in the prevention and management of their spread.

Intraspecific, ecotypic and home climate variation in photosynthetic traits of the widespread invasive grass Johnsongrass.

Despite their near ubiquity across global ecosystems, the underlying mechanisms contributing to the success of invasive plants remain largely unknown. In particular, ecophysiological traits, which are fundamental to plants' performance and response to their environment, are poorly understood with respect to geographic and climate space. We evaluated photosynthetic trait variation among populations, ecotypes and home climates (i.e. the climates from the locations they were collected) of the widespread and expanding invader Johnsongrass (Sorghum halepense). We found that populations vary in the maximum net photosynthetic flux and the light-saturated net photosynthetic rate, and that agricultural and non-agricultural ecotypes vary in apparent quantum yield and water-use efficiency (WUE). We also found that populations from warmer home climates had lower dark respiration rates, light compensation points and WUEs. As Johnsongrass expands across the USA the abiotic and biotic environments are driving variation in its genetics, phenotypes and its underlying physiology. Our study demonstrates the importance of evaluating physiological traits in invasive plants, especially as they relate to home climates.

Silkworm Silk Fiber Bundles as Improved In Vitro Scaffolds for Skeletal Muscle.

To mimic skeletal muscle tissues in vitro, native and transgenic spider silk/silkworm silks were seeded with C2C12 myoblasts to observe if these three-dimensional substrates are preferable to a traditional two-dimensional polystyrene cell culture surface. Silks were wound around an acrylic chassis to produce a novel, three-dimensional cell culture device with suspended muscle fibers that genetically and morphologically resemble native skeletal muscle tissue. The transgenic spider silk/silkworm silk has never before been studied for this application. Genetic expression verified skeletal muscle lineage and differentiation, while fluorescent imaging verified contractile protein synthesis. Genetic analysis also revealed an increase in expression of the Myh2 contractile protein gene on silkworm silks, particularly on the transgenic silk. Mechanical properties and protein secondary structure content of the silks indicated correlation between substrate properties and Myh2 gene expression. This increase in contractile protein gene expression suggests that biologically derived silk substrates that are suspended may be a preferable substrate for in vitro muscle modeling because of the proteinaceous character and mechanical flexibility of the silk.

The Evolution of an Invasive Plant, Sorghum halepense L. ('Johnsongrass').

From noble beginnings as a prospective forage, polyploid Sorghum halepense ('Johnsongrass') is both an invasive species and one of the world's worst agricultural weeds. Formed by S. bicolor x S. propinquum hybridization, we show S. halepense to have S. bicolor-enriched allele composition and striking mutations in 5,957 genes that differentiate it from representatives of its progenitor species and an outgroup. The spread of S. halepense may have been facilitated by introgression from closely-related cultivated sorghum near genetic loci affecting rhizome development, seed size, and levels of lutein, a photochemical protectant and abscisic acid precursor. Rhizomes, subterranean stems that store carbohydrates and spawn clonal propagules, have growth correlated with reproductive rather than other vegetative tissues, and increase survival of both temperate cold seasons and tropical dry seasons. Rhizomes of S. halepense are more extensive than those of its rhizomatous progenitor S. propinquum, with gene expression including many alleles from its non-rhizomatous S. bicolor progenitor. The first surviving polyploid in its lineage in ∼96 million years, its post-Columbian spread across six continents carried rich genetic diversity that in the United States has facilitated transition from agricultural to non-agricultural niches. Projected to spread another 200-600 km northward in the coming century, despite its drawbacks S. halepense may offer novel alleles and traits of value to improvement of sorghum.

Effect of growth media and phase on Raman spectra and discrimination of mycobacteria.

When developing a Raman spectral library to identify bacteria, differences between laboratory and real world conditions must be considered. For example, culturing bacteria in laboratory settings is performed under conditions for ideal bacteria growth. In contrast, culture conditions in the human body may differ and may not support optimized bacterial growth. To address these differences, researchers have studied the effect of conditions such as growth media and phase on Raman spectra. However, the majority of these studies focused on Gram-positive or Gram-negative bacteria. This article focuses on the influence of growth media and phase on Raman spectra and discrimination of mycobacteria, an acid-fast genus. Results showed that spectral differences from growth phase and media can be distinguished by spectral observation and multivariate analysis. Results were comparable to those found for other types of bacteria, such as Gram-positive and Gram-negative. In addition, the influence of growth phase and media had a significant impact on machine learning models and their resulting classification accuracy. This study highlights the need for machine learning models and their associated spectral libraries to account for various growth parameters and stages to further the transition of Raman spectral analysis of bacteria from laboratory to clinical settings.