Effect of amoxicillin on the gut microbiome of children with severe acute malnutrition in Madarounfa, Niger: a retrospective metagenomic analysis of a placebo-controlled trial

BACKGROUND

Children with severe acute malnutrition are treated with antibiotics as outpatients. We aimed to determine the effect of 7 days of amoxicillin on acute and long-term changes to the gut microbiome and antibiotic resistome in children treated for severe acute malnutrition.

METHODS

We conducted a secondary analysis of a randomised, double-blinded, placebo-controlled trial (NCT01613547) of amoxicillin in children (aged 6-59 months) with severe acute malnutrition treated as outpatients in Madarounfa, Niger. We randomly selected 161 children from the overall cohort (n=2399) for initial 12-week follow-up from Sept 23, 2013 to Feb 3, 2014. We selected a convenience sample of those 161 children, on the basis of anthropometric measures, for follow-up 2 years later (Sept 28 to Oct 27, 2015). Children provided faecal samples at baseline, week 1, week 4, week 8, week 12, and, for those in the 2-year follow-up cohort, week 104. We conducted metagenomic sequencing followed by microbiome and resistome profiling of faecal samples. 38 children without severe acute malnutrition and six children with severe acute malnutrition matching the baseline ages of the original cohort were used as reference controls.

FINDINGS

In the 12-week follow-up group, amoxicillin led to an immediate decrease in gut microbiome richness from 37·6 species (95% CI 32·6-42·7) and Shannon diversity index (SDI) 2·18 (95% CI 1·97-2·39) at baseline to 27·7 species (95% CI 22·9-32·6) species and SDI 1·55 (95% CI 1·35-1·75) at week 1. Amoxicillin increased gut antibiotic resistance gene abundance to 6044 reads per kilobase million (95% CI 4704-7384) at week 1, up from 4800 (3391-6208) at baseline, which returned to baseline 3 weeks later. 35 children were included in the 2-year follow-up; the amoxicillin-treated children (n=22) had increased number of species in the gut microbiome compared with placebo-treated children (n=13; 60·7 [95% CI 54·7-66·6] vs 36·9 [29·4-44·3]). Amoxicillin-treated children had increased Prevotella spp and decreased Bifidobacterium spp relative to age-matched placebo-treated children, indicating a more mature, adult-like microbiome.

INTERPRETATION

Amoxicillin treatment led to acute but not sustained increases in antimicrobial resistance genes and improved gut microbiome maturation 2 years after severe acute malnutrition treatment.

FUNDING

Bill & Melinda Gates Foundation; Médecins sans Frontières Operational Center Paris; National Institute of Allergy and Infectious Diseases; National Institute of General Medical Sciences; Eunice Kennedy Shriver National Institute of Child Health and Human Development; Edward Mallinckrodt Jr Foundation; Doris Duke Foundation.

Poor health-related quality of life in postural orthostatic tachycardia syndrome in comparison with a sex- and age-matched normative population

PURPOSE

The effect of postural orthostatic tachycardia syndrome (POTS) on health-related quality of life (HrQoL) remains poorly studied. Here, we sought to compare the HrQoL in individuals with POTS to a normative age-/sex-matched population.

METHODS

Participants enrolled in the Australian POTS registry between 5 August 2021 and 30 June 2022 were compared with propensity-matched local normative population data from the South Australian Health Omnibus Survey. The EQ-5D-5L instrument was used to assess HrQoL across the five domains (mobility, self-care, usual activities, pain/discomfort, and anxiety/depression) with global health rating assessed with a visual analog scale (EQ-VAS). A population-based scoring algorithm was applied to the EQ-5D-5L data to calculate utility scores. Hierarchical multiple regression analyses were undertaken to explore predictors of low utility scores.

RESULTS

A total of 404 participants (n = 202 POTS; n = 202 normative population; median age 28 years, 90.6% females) were included. Compared with the normative population, the POTS cohort demonstrated significantly higher burden of impairment across all EQ-5D-5L domains (all P < 0.001), lower median EQ-VAS (p < 0.001), and lower utility scores (p < .001). The lower EQ-VAS and utility scores in the POTS cohort were universal in all age groups. Severity of orthostatic intolerance symptoms, female sex, fatigue scores, and comorbid diagnosis of myalgic encephalomyelitis/chronic fatigue syndrome were independent predictors of reduced HrQoL in POTS. The disutility in those with POTS was lower than many chronic health conditions.

CONCLUSIONS

This is the first study to demonstrate significant impairment across all subdomains of EQ-5D-5L HrQoL in the POTS cohort as compared with a normative population.

TRIAL REGISTRATION

ACTRN12621001034820.

High incidence of autonomic dysfunction and postural orthostatic tachycardia syndrome in patients with long-COVID: Implications for management and healthcare planning

BACKGROUND

Autonomic dysfunction including postural orthostatic tachycardia syndrome (POTS) has been reported in individuals with post-acute sequelae of Covid-19 (PASC). However, the degree of dysautonomia in PASC has not been compared to those with POTS and healthy controls.

METHODS

All participants were prospectively enrolled between 5^th August 2021 and 31^st October 2022. Autonomic testing included beat-to-beat hemodynamic monitoring to assess respiratory sinus arrhythmia, Valsalva ratio and orthostatic changes during a 10-minute active standing test as well as Sudomotor assessment. The Composite Autonomic Symptom Score (COMPASS-31) was used to assess symptoms and the Euroquol 5-Dimension survey (EQ-5D-5L) was used to assess health-related quality of life (HrQoL) measures.

RESULTS

A total of 99 participants (n=33 PASC, n=33 POTS and n=33 healthy controls; median age 32 [18], 85.9% females) were included. Compared to healthy controls, the PASC and POTS cohorts demonstrated significantly reduced respiratory sinus arrhythmia (p<0.001), greater heart rate increase during 10-minute active standing test (p<0.001), greater burden of autonomic dysfunction evidenced by higher COMPASS-31 scores across all subdomains (all p<0.001) and poor HrQoL across all EQ-5D-5L domains (all p<0.001), lower median EQ-VAS (p<0.001) and lower utility scores (p<0.001). The majority (79%) of those with PASC met the internationally established criteria for POTS.

CONCLUSION

The prevalence of autonomic symptomology or POTS was high in those with PASC, leading to poor HrQoL and high health disutility. Autonomic testing should be routinely undertaken in those with PASC to aid diagnosis and direct appropriate management to improve health outcomes.

TRIAL REGISTRATION

ANZCTR 12621000476831.

Microbiota restoration reduces antibiotic-resistant bacteria gut colonization in patients with recurrent Clostridioides difficile infection from the open-label PUNCH CD study

BACKGROUND

Once antibiotic-resistant bacteria become established within the gut microbiota, they can cause infections in the host and be transmitted to other people and the environment. Currently, there are no effective modalities for decreasing or preventing colonization by antibiotic-resistant bacteria. Intestinal microbiota restoration can prevent Clostridioides difficile infection (CDI) recurrences. Another potential application of microbiota restoration is suppression of non-C. difficile multidrug-resistant bacteria and overall decrease in the abundance of antibiotic resistance genes (the resistome) within the gut microbiota. This study characterizes the effects of RBX2660, a microbiota-based investigational therapeutic, on the composition and abundance of the gut microbiota and resistome, as well as multidrug-resistant organism carriage, after delivery to patients suffering from recurrent CDI.

METHODS

An open-label, multi-center clinical trial in 11 centers in the USA for the safety and efficacy of RBX2660 on recurrent CDI was conducted. Fecal specimens from 29 of these subjects with recurrent CDI who received either one (N = 16) or two doses of RBX2660 (N = 13) were analyzed secondarily. Stool samples were collected prior to and at intervals up to 6 months post-therapy and analyzed in three ways: (1) 16S rRNA gene sequencing for microbiota taxonomic composition, (2) whole metagenome shotgun sequencing for functional pathways and antibiotic resistome content, and (3) selective and differential bacterial culturing followed by isolate genome sequencing to longitudinally track multidrug-resistant organisms.

RESULTS

Successful prevention of CDI recurrence with RBX2660 correlated with taxonomic convergence of patient microbiota to the donor microbiota as measured by weighted UniFrac distance. RBX2660 dramatically reduced the abundance of antibiotic-resistant Enterobacteriaceae in the 2 months after administration. Fecal antibiotic resistance gene carriage decreased in direct relationship to the degree to which donor microbiota engrafted.

CONCLUSIONS

Microbiota-based therapeutics reduce resistance gene abundance and resistant organisms in the recipient gut microbiome. This approach could potentially reduce the risk of infections caused by resistant organisms within the patient and the transfer of resistance genes or pathogens to others.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT01925417 ; registered on August 19, 2013.

Awake tracheal intubation in a suspected COVID-19 patient with critical airway obstruction

We report the airway management of a patient with suspected COVID-19 with impending airway obstruction requiring urgent surgical tracheostomy. To our knowledge, this is the first reported case of an awake tracheal intubation in a suspected COVID-19-positive patient. Various modifications were put in place during the awake tracheal intubation and surgical tracheostomy procedures to minimise aerosol generation from the patient, such as avoiding high-flow nasal oxygen, establishing conscious sedation with remifentanil before commencing airway topicalisation and avoiding transtracheal local anaesthetic infiltration. A multidisciplinary team discussion before performing the case highlighted aspects of both the airway management and the surgical procedure where particular care and modifications are required. There is a lack of national and international guidance for awake tracheal intubation and tracheostomy in COVID-19 cases. This report nevertheless addresses the key procedural modifications required.

The effects of antibiotics on the microbiome throughout development and alternative approaches for therapeutic modulation

The widespread use of antibiotics in the past 80 years has saved millions of human lives, facilitated technological progress and killed incalculable numbers of microbes, both pathogenic and commensal. Human-associated microbes perform an array of important functions, and we are now just beginning to understand the ways in which antibiotics have reshaped their ecology and the functional consequences of these changes. Mounting evidence shows that antibiotics influence the function of the immune system, our ability to resist infection, and our capacity for processing food. Therefore, it is now more important than ever to revisit how we use antibiotics. This review summarizes current research on the short-term and long-term consequences of antibiotic use on the human microbiome, from early life to adulthood, and its effect on diseases such as malnutrition, obesity, diabetes, and Clostridium difficile infection. Motivated by the consequences of inappropriate antibiotic use, we explore recent progress in the development of antivirulence approaches for resisting infection while minimizing resistance to therapy. We close the article by discussing probiotics and fecal microbiota transplants, which promise to restore the microbiota after damage of the microbiome. Together, the results of studies in this field emphasize the importance of developing a mechanistic understanding of gut ecology to enable the development of new therapeutic strategies and to rationally limit the use of antibiotic compounds.

Integrated water cycle planning for towns in New South Wales, Australia

Integration means different things to different people and as a consequence appears to only partially deliver on promised outcomes. For effective integrated water cycle management these outcomes should include improved water use efficiency, less waste, environmental sustainability, and provide secure and reliable supply to meet social and economic needs. The objective of integration is the management and combination of all these outcomes as part of a whole, so as to provide better outcomes than would be expected by managing the parts independently. Integration is also a consequence of the Water Reforms embarked on by the NSW State Government in 1995. The key goals of the reforms are clean and healthy rivers and groundwaters, and the establishment of more secure water entitlements for users. They are also essential for meeting the Council of Australian Government (COAG) water management strategies. The policies and guidelines that formed the NSW Water Reforms were the basis of the Water Management Act 2000 (NSW) (WMA) which is the legislative framework for water management in NSW. The NSW Department of Land and Water Conservation has developed an approach to integrated water cycle management for rural centres in NSW based on a catchment and policy context. This approach includes consideration of catchment wide needs and issues, environmental sustainability, government policy and community objectives in the development of an integrated water cycle plan. The approach provides for a transparent assessment of priorities and how to deal with them, and while specific to urban centres, could easily be expanded for use in the management of the whole of the catchment water cycle. Integration of the water cycle is expected to offer benefits to the local environment, community and economy. For instance, any unused proportion of an urban centre's water entitlement, or an offset against this entitlement created through returned flows (such as via good quality sewage effluent discharge to a river), can provide a surplus which is available to be traded on an annual basis. Further, improved demand management within an urban centre can be expected to result in a reduction in abstraction against the licence entitlement. This may result in the increased availability of in-stream water for environmental or other purposes and is expected to increase the economic value of returned water. Improved water use efficiencies are also expected to result in reduced capital works (and their associated costs) as the efficiency of service delivery and resource use improves. In this paper an example of the application of this process is provided and the outcomes discussed.

Antimicrobial use in a small rural hospital

An audit was done to determine the pattern of antimicrobial use in a small rural Canadian hospital. Over a three-month period, 85 (33.7%) of 252 hospitalized patients received systemic antimicrobials. The group comprised 19 children and 66 adults. Respiratory infections were most common in both children and adults, and ampicillin/amoxicillin was the most frequently used agent. Treatment was judged to be appropriate in all the children, but was inappropriate in 15% of the adults. Adults who had superficial skin infections, and urinary tract infections with catheters in place, were most often inappropriately treated with systemic antimicrobials. The causes of inappropriate antimicrobial use and how to prevent it are discussed.

Solitary diverticulitis of the right colon

Inflammation of a solitary diverticulum of the right colon is uncommon; approximately 500 cases have been reported. A 72-year-old woman underwent laparotomy for possible appendicitis. Unexpectedly, a mass was found in the ascending colon close to the ileocecal junction. Carcinoma was suspected and right hemicolectomy was done. The pathological diagnosis was acute suppurative solitary diverticulitis with perforation and pericolic abscess. From his case and a review of the literature the author concludes that inflammation in a solitary diverticulum of the cecum is a distinct entity. Its etiology is uncertain, but a congenital origin is widely accepted. Clinically it mimics appendicitis; at operation it is often indistinguishable from carcinoma. Roentgenogram after a barium enema is diagnostic. The condition is treated by diverticulectomy, wedge resection or colectomy. Abscesses are drained.