Effects of Bacillus subtilis on in vitro ruminal fermentation and methane production.

The objective of this study was to evaluate the effect of a proprietary strain of a Bacillus subtilis on in vitro ruminal fermentation and methane production in batch culture serum bottles. One hundred forty-nine batch culture bottles were used in a complete randomized block design. The arrangement of treatments was a 3 × 3 × 4 factorial to evaluate the effects of inoculum, time, diet, and their respective interactions. There were three experimental runs total, where the run was used as block. Inoculum treatments were 1.85 mg/mL of microcrystalline cellulose (CON); 10 billion B. subtilis plus microcrystalline cellulose (A1); and 60 billion B. subtilis plus microcrystalline cellulose (A2). Diet treatments were 0.50 g of early lactation diet (E, 30% starch), mid-lactation diet (M, 25% starch), or dry cow diet (D, 18% starch). The combination resulted in total of nine treatments. Each treatment had five replicates, two of which were used to determine nutrient degradability at 24 and 48 h after inoculation, and three were used to determine pH, ammonia nitrogen (NH3-N), volatile fatty acids, lactate, total gas, and methane production at 3, 6, 24, and 48 h after inoculation. Fixed effects of inoculum, diet, and their interaction were tested using the GLIMMIX procedure of SAS. Significance was declared at P ≤ 0.05. We observed that, compared to control, the supplementation of B. subtilis, decreased the production of acetate and propionate, while increasing the production of butyrate, iso-butyrate, valerate, iso-valerate, and caproate within each respective diet. Additionally, the total methane production exhibited mixed responses depending on the diet type. Overall, the inclusion of B. subtilis under in vitro conditions shows the potential to reduce ruminal methane production when supplemented with a mid-lactation diet, constituting a possible methane mitigation additive for dairy cattle diets.

Describing the Lived Experience and Resource Needs of Individuals With Long COVID.

Individuals with long COVID report diverse symptoms lasting weeks or months after initial infection, causing significant psychosocial distress. Navigating health care interactions are often difficult for these individuals due to the diffuse nature of their symptoms, a lack of effective treatment options, and skepticism from some providers. To better understand these challenges, this study sought to further describe the lived experience of individuals with long COVID. A survey was conducted with individuals evaluated for long COVID at a specialty clinic (n = 200), which included questions about prior conditions, symptoms, use of medical and support services, and information and resource needs. Participants reported a mean of 10.75 persistent symptoms, the most common being fatigue and difficulty concentrating, with broad effects on daily functioning. Participants saw a mean of 5.92 providers for treatment of their symptoms, and 88.5% identified health care providers as a trusted source of information. Interest in research findings (60.5%) and opportunities for participation (47.5%) were moderate and varied by COVID vaccination status. Unvaccinated individuals (n = 27) also reported less trust in government sources of information, less college education, lower household income, and greater likelihood of having public insurance. Our findings suggest that individuals with long COVID experience many ongoing and complex symptoms with diverse effects on daily living; that health care providers are an important source for public health messaging about long COVID; and that unvaccinated individuals are likely to have differing needs and receptiveness to information than vaccinated individuals with long COVID.

An Exploratory Qualitative Analysis of Explanations for COVID-19-Related Racial Disparities Among St. Louis Residents: "I Don't Really Pay Attention to the Racial Stuff Very Much".

Introduction: Public health explanations for the disproportionate share of COVID-19-related illness and death among the Black population often differ from lay explanations, which can affect the public's support for policies that address these disparities. This qualitative exploratory study examined the explanatory frameworks for COVID-19-related racial disparities in St. Louis among 54 St. Louis residents. Methods: From August 16, 2021, through May 20, 2022, we conducted semistructured interviews among a convenience sample of 54 St. Louis residents about their experiences during the COVID-19 pandemic. Directed content analysis identified participants' explanatory frameworks for racial disparities in COVID-19-related illness and death. We disaggregated coded excerpts by race, age, education, and income to examine emerging themes. Results: Lay explanatory frameworks for racial disparities in COVID-19 included vaccine mistrust, lack of personal responsibility, low perceived susceptibility to COVID-19, pre-existing conditions or genetic predisposition, institutional racism, barriers to care, low socioeconomic status, insufficient information on COVID-19, and the inability to work remotely. Black interview participants addressed issues of systemic racism, inequitable allocation of COVID-19 vaccines, and institutional mistrust, whereas White participants did not directly acknowledge the role of racism. Both Black and White participants identified lack of personal responsibility among young Black people as a source of these disparities. Conclusion: This work identifies a need for improved health communication about racial disparities in COVID-19-related illness and death. Messaging that highlights racism may be less effective among the White population than the Black population in the US, whereas narratives that include the theme of individual choice may appeal broadly. Further research is needed on the use of communication strategies based on lay individuals' explanatory frameworks for COVID-19-related racial disparities to enhance support for equitable public policy.

In vitro evaluation of microencapsulated organic acids and pure botanicals as a supplement in lactating dairy cows diet on in vitro ruminal fermentation.

The utilization of microencapsulated organic acids and pure botanicals (mOAPB) is widely used in the monogastric livestock industry as an alternative to antibiotics; in addition, it can have gut immunomodulatory functions. More recently, an interest in applying those compounds in the ruminant industry has increased; thus, we evaluated the effects of mOAPB on ruminal fermentation kinetics and metabolite production in an in vitro dual-flow continuous-culture system. For this study, two ruminal cannulated lactating dairy Holstein cows were used as ruminal content donors, and the inoculum was incubated in eight fermenters arranged in a 4 × 4 Latin square design. The basal diet was formulated to meet the nutritional requirements of a 680-kg Holstein dairy cow producing 45 kg/d of milk and supplemented with increasing levels of mOAPB (0; 0.12; 0.24; or 0.36% of dry matter [DM]), which contained 55.6% hydrogenated and refined palm oil, 25% citric acid, 16.7% sorbic acid, 1.7% thymol, and 1% vanillin. Diet had 16.1 CP, 30.9 neutral detergent fiber (NDF), and 32.0 starch, % of DM basis, and fermenters were fed 106 g/d split into two feedings. After a 7 d adaptation, samples were collected for 3 d in each period. Samples of the ruminal content from the fermenters were collected at 0, 1, 2, 4, 6, and 8 h postmorning feeding for evaluation of the ruminal fermentation kinetics. For the evaluation of the daily production of total metabolites and for the evaluation of nutrient degradability, samples from the effluent containers were collected daily at days 8 to 10. The statistical analysis was conducted using MIXED procedure of SAS and treatment, time, and its interactions were considered as fixed effects and day, Latin square, and fermenter as random effects. To depict the treatment effects, orthogonal contrasts were used (linear and quadratic). The supplementation of mOAPB had no major effects on the ruminal fermentation, metabolite production, and degradability of nutrients. The lack of statistical differences between control and supplemented fermenters indicates effective ruminal protection and minor ruminal effects of the active compounds. This could be attributed to the range of daily variation of pH, which ranged from 5.98 to 6.45. The pH can play a major role in the solubilization of lipid coat. It can be concluded that mOAPB did not affect the ruminal fermentation, metabolite production, and degradability of dietary nutrients using an in vitro rumen simulator.

A histological analysis of coloration in the Peruvian mimic poison frog (Ranitomeya imitator).

Aposematism continues to be a phenomenon of central interest in evolutionary biology. The life history of the mimic poison frog, Ranitomeya imitator, relies heavily on aposematism. In order for aposematic signals to be effective, predators must be able to learn to avoid the associated phenotype. However, in R. imitator, aposematism is associated with four different color phenotypes that mimic a complex of congeneric species occurring across the mimic frog's geographic range. Investigations of the underlying mechanics of color production in these frogs can provide insights into how and why these different morphs evolved. We used histological samples to examine divergence in the color production mechanisms used by R. imitator to produce effective aposematic signals across its geographic range. We measured the coverage of melanophores and xanthophores (the area covered by chromatophores divided by total area of the skin section) in each color morph. We find that morphs that produce orange skin exhibit a higher coverage of xanthophores and lower coverage of melanophores than those that produce yellow skin. In turn, morphs that produce yellow skin exhibit a higher coverage of xanthophores and lower coverage of melanophores than those that produce green skin. Generally, across the morphs, a high ratio of xanthophores to melanophores is associated with colors of brighter spectral reflectance. Together, our results contribute to the understanding of color production in amphibians and document divergence in the histology of a species that is subject to divergent selection associated with aposematism.

Can dietary magnesium sources and buffer change the ruminal microbiota composition and fermentation of lactating dairy cows?

Magnesium oxide (MgO) is one of the most used Mg supplements in livestock. However, to avoid relying upon only one Mg source, it is important to have alternative Mg sources. Therefore, the objective of this study was to evaluate the effects of the interaction of two Mg sources with buffer use on the ruminal microbiota composition, ruminal fermentation, and nutrient digestibility in lactating dairy cows. Twenty lactating Holstein cows were blocked by parity and days in milk into five blocks with four cows each, in a 2 × 2 factorial design. Within blocks, cows were assigned to one of four treatments: 1) MgO; 2) MgO + Na sesquicarbonate (MgO+); 3) calcium-magnesium hydroxide (CaMgOH); 4) CaMgOH + Na sesquicarbonate (CaMgOH+). For 60 d, cows were individually fed a corn silage-based diet, and treatments were top-dressed. Ruminal fluid was collected via an orogastric tube, for analyses of the microbiota composition, volatile fatty acids (VFA), lactate, and ammonia nitrogen (NH3-N). The microbiota composition was analyzed using V4/16S rRNA gene sequencing, and taxonomy was assigned using the Silva database. Statistical analysis was carried out following the procedures of block design analysis, where block and cow were considered random variables. Effects of Mg source, buffer, and the interaction between Mg Source × Buffer were analyzed through orthogonal contrasts. There was no interaction effect of the two factors evaluated. There was a greater concentration of NH3-N, lactate, and butyrate in the ruminal fluid of cows fed with CaMg(OH)2, regardless of the buffer use. The increase in these fermentation intermediates/ end-products can be explained by an increase in abundance of micro-organisms of the genus Prevotella, Lactobacillus, and Butyrivibrio, which are micro-organisms mainly responsible for proteolysis, lactate-production, and butyrate-production in the rumen, respectively. Also, dietary buffer use did not affect the ruminal fermentation metabolites and pH; however, an improvement of the apparent total tract digestibility of dry matter (DM), organic matter (OM), neutral fiber detergent (NDF), and acid fiber detergent (ADF) were found for animals fed with dietary buffer. In summary, there was no interaction effect of buffer use and Mg source, whereas buffer improved total tract apparent digestibility of DM and OM through an increase in NDF and ADF digestibility and CaMg(OH)2 increased ruminal concentration of butyrate and abundance of butyrate-producing bacteria.

Magnesium oxide (MgO) is extensively used as a dietary magnesium (Mg) source in dairy cow diets. However, dairy operations can benefit from other Mg sources. Thus, we evaluated the replacement of dietary MgO with calcium­magnesium hydroxide (CaMg(OH)2) in diets with and without ruminal buffer and their effects on the ruminal microbiota composition, ruminal fermentation, and nutrient digestibility in lactating dairy cows. The study used 20 lactating Holstein cows that were blocked in groups of four and randomly assigned to one of the four treatments. The ruminal content, feed, feces, and urine were collected for analysis of the microbiota composition, ruminal fermentation, nitrogen metabolism, and apparent nutrient digestibility. There was no interaction effect of dietary buffer use and Mg source, while buffer improved total tract apparent digestibility of the dry matter and fiber components; CaMg(OH)2 increased the ruminal concentration of butyrate and the abundance of butyrate-producing bacteria. In summary, we conclude that using CaMg(OH)2 can improve ruminal fermentation regardless of buffer use, which indicates that we can take advantage of the mineral formulation in the diet to modulate the ruminal microbiota composition.

Challenges in Treating Mycobacterium chelonae/abscessus Prosthetic Joint Infection.

Prosthetic joint infections (PJIs) remain a major complication of arthroplasty, most of which are caused by Staphylococcus aureus and gram-negative bacteria. Unfortunately, cultures are false negative in upward of 7 percent of patients with suspected PJIs, and commonly in infections caused by rare rapidly growing mycobacterium (RGM) species. Guidelines recommend 6 months of antimycobacterial therapy for bone diseases caused by RGM, with empiric therapy consists of an oral macrolide (clarithromycin or azithromycin) plus tobramycin and imipenem-cilastatin. Definitive treatment of PJI due to RGM should be guided by antimicrobial susceptibility, however, most microbiology laboratories are unable to differentiate between M. chelonae and M. abscessus. Furthermore, treatment of M. chelonae PJI is challenging due to multidrug resistance and the dearth of oral antibiotics for therapy. This case report investigates a patient with PJI caused by M. chelonae and M. abscessus. The initial treatment with imipenem-cilastatin was complicated by drug induced seizures, further limiting therapy options.

Real-world impact of switching from tenofovir disoproxil fumarate to tenofovir alafenamide.

Although tenofovir disoproxil fumarate (TDF) and tenofovir alafenamide (TAF) have been evaluated in various clinical trials, limited safety and efficacy data exist in real-world settings. The goal of this retrospective analysis is to assess changes in virological suppression, immunological status, renal function, weight and body mass index (BMI) amongst people living with HIV who switched from a TDF-based to a TAF-based regimen. Of 130 patients included in the final analysis, 53 patients experienced an increase in their viral load upon switching from TDF to TAF therapy whilst 62 patients remained undetectable. For those who experienced a viral blip, 33 (62%) resuppressed by the time of last follow-up, 15 (28%) patients did not have additional labs beyond the last follow-up and concern for failure occurred in 5 (9%) patients. No differences in immunological function, renal function, weight or BMI were observed from before switching to the last follow-up. Although a loss of virological suppression was found upon switching to TAF at subsequent follow-up visits, resuppression ultimately occurred in most patients.

The race to a COVID-19 vaccine: opportunities and challenges in development and distribution.

The unprecedented toll of severe acute respiratory syndrome coronavirus 2, the virus responsible for coronavirus 2019 disease (COVID-19), jumpstarted the race towards the development and distribution of effective treatment and prevention options. With an urgent need to slow viral transmission, lessen disease severity, and reduce mortality, biopharmaceutical companies rapidly began investigating potential COVID-19 vaccinations. While typical vaccine development can take upwards of 10-15 years, COVID-19 vaccines were developed in less than a year after the identification of COVID-19. To accomplish this feat, clinical development, manufacturing scale-up and distribution are occurring in parallel for the four COVID-19 vaccine front-runners. This remarkable opportunity will forever change the drug development process and would not be possible without tremendous dedication from the public and private sectors, researchers, and clinical trial volunteers. However, many challenges still lie ahead. Comprehensive plans for equitable vaccine education, distribution, administration and post-marketing surveillance must be implemented successfully to overcome vaccine hesitancy, supply-chain obstacles and healthcare provider shortages in an already overburdened healthcare system. We are moving forward at a remarkable pace but worldwide immunity through vaccination will take time to achieve. Thus, current prevention efforts of masking, hand hygiene and social distancing must remain in effect for the foreseeable future. We must remain diligent and not fatigue in our efforts. Ending the COVID-19 pandemic cannot rest on the promise of vaccination alone - it will require a continued, robust and multi-faceted approach to disease treatment and prevention.