Detection of SARS-CoV-2 from patient fecal samples by whole genome sequencing

Improvements in Gut Microbiome Composition and Clinical Symptoms Following Familial Fecal Microbiota Transplantation in a Nineteen-Year-Old Adolescent With Severe Autism

This case report describes a novel therapy for patients with severe autism spectrum disorder (ASD) that is worth further investigation. A 19-year-old male adolescent with ASD, who was not responding to standard treatment received fecal microbiota transplant (FMT) using donor material from his typically developing female sibling. The patient's ASD symptoms were assessed by assessors who were blind to the patient's past ASD symptomatology. Assessors used the Childhood Autism Rating Scale (CARS), an observation-based rating scale to assess developmental delay in children with autism (range of CARS scores is 15 - 60; a score > 28 is indicative of autism; higher score is positively correlated with degree of severity), at baseline and again at six timepoints post-FMT. The patient experienced marked improvements in microbiome diversity and composition over the year and a half period that followed the FMT procedure. Additionally, the patient who was previously nonverbal said his first two words and experienced a reduction in aggression 1-month post-FMT. To the authors' knowledge, this is the first report to demonstrate the use of familial FMT in an adolescent patient with ASD. Given that ASD symptom improvements post-FMT tend to occur in younger patients, the authors hypothesize that the use of a familial donor may be an important factor that contributed to the improved outcomes experienced by this older child.

Targeted Sequencing Approach and Its Clinical Applications for the Molecular Diagnosis of Human Diseases

The outbreak of COVID-19 has positively impacted the NGS market recently. Targeted sequencing (TS) has become an important routine technique in both clinical and research settings, with advantages including high confidence and accuracy, a reasonable turnaround time, relatively low cost, and fewer data burdens with the level of bioinformatics or computational demand. Since there are no clear consensus guidelines on the wide range of next-generation sequencing (NGS) platforms and techniques, there is a vital need for researchers and clinicians to develop efficient approaches, especially for the molecular diagnosis of diseases in the emergency of the disease and the global pandemic outbreak of COVID-19. In this review, we aim to summarize different methods of TS, demonstrate parameters for TS assay designs, illustrate different TS panels, discuss their limitations, and present the challenges of TS concerning their clinical application for the molecular diagnosis of human diseases.

Vitamin C improves gut Bifidobacteria in humans

Aims: Numerous beneficial effects of vitamin C (ascorbic acid) supplementation have been reported in the literature. However, data on its effects toward the gut microbiome are limited. We assessed the effect of vitamin C supplementation on the abundance of beneficial bacterial species in the gut microbiome. Materials and methods: Stool samples were analyzed for relative abundance of gut microbiome bacteria using next-generation sequencing-based profiling and metagenomic shotgun analysis. Results: Supplementation with vitamin C increased the abundance of bacteria of the genus Bifidobacterium (p = 0.0001) and affected various species. Conclusion: The beneficial effects of vitamin C supplementation may be attributed to modulation of the gut microbiome and the consequent health benefits thereof.

Herbal medicine in the treatment of COVID-19 based on the gut-lung axis

Respiratory symptoms are most commonly experienced by patients in the early stages of novel coronavirus disease 2019 (COVID-19). However, with a better understanding of COVID-19, gastrointestinal symptoms such as diarrhea, nausea, and vomiting have attracted increasing attention. The gastrointestinal tract may be a target organ of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. The intestinal microecological balance is a crucial factor for homeostasis, including immunity and inflammation, which are closely related to COVID-19. Herbal medicine can restore intestinal function and regulate the gut flora structure. Herbal medicine has a long history of treating lung diseases from the perspective of the intestine, which is called the gut-lung axis. The physiological activities of guts and lungs influence each other through intestinal flora, microflora metabolites, and mucosal immunity. Microecological modulators are included in the diagnosis and treatment protocols for COVID-19. In this review, we demonstrate the relationship between COVID-19 and the gut, gut-lung axis, and the role of herbal medicine in treating respiratory diseases originating from the intestinal tract. It is expected that the significance of herbal medicine in treating respiratory diseases from the perspective of the intestinal tract could lead to new ideas and methods for treatment.

Graphical abstract

http://links.lww.com/AHM/A33.

Comparison of SARS-CoV-2 spike RNA sequences in feces and nasopharynx indicates intestinal replication

Background

Little is known of possible selection and replication of SARS-CoV-2 in the intestines and if viral load in feces is associated with severity of disease. Therefore, sequence variations of the spike region in strains collected from feces and nasopharynx (NPH) from the same patients were compared. It was also investigated whether viral load in feces related to severity of COVID-19 in hospitalized patients.

Results

SARS-CoV-2 RNA was found in 88 (79%) fecal samples from 112 patients. The complete spike region could be sequenced in 15 fecal and 14 NPH samples. Fourteen Alpha-variants and one Beta-variant of SARS-CoV-2 were identified. The majority of the viral genetic variants (viral populations) in two fecal samples, but none in NPH, had a reversion of the H69/V70 amino acid deletion normally seen in the Alpha variants. Nine fecal samples contained up to nine minority variants, each which may constitute a separate viral population. Five NPH samples had one genetic variant each, and one NPH sample contained nine minority populations of SARS-CoV-2 spike genes.

Conclusions

The higher genomic diversity of SARS-CoV-2 in feces compared to NPH, and the reversion of the H69/V70 deletion in Alpha variants from feces indicate a selection of viral strains and replication of SARS-CoV-2 in the gastrointestinal tract.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13099-022-00509-w.

A Methodological Approach to Water Concentration to Investigate the Presence of SARS-CoV-2 RNA in Surface Freshwaters

During the COVID-19 public health emergency, an increasing number of studies reported the occurrence of SARS-CoV-2 in wastewaters worldwide, but little is known about the presence of the virus in surface freshwaters. The aim of the current study was to develop and validate an appropriate and scalable methodological approach for the concentration and detection of SARS-CoV-2 from surface freshwater samples, collected within the Milan rural network subjected to flood spillways activity. Overall, both surface water and distilled water samples spiked with inactivated SARS-CoV-2 were used to validate the concentration method for pathogens determination. Two pre-filtration systems, filter paper and Sartolab® P20 (Sartorius, Germany) and two concentration methods, two-phase (PEG-dextran method) separation and tangential flow ultrafiltration (UF), were compared. The effects of pre-filtration and concentration on viral nucleic acid recovery were assessed through real time RT-PCR targeting SARS-CoV-2 and the internal viral control PMMoV (Pepper Mild Mottle Virus). Our results showed that UF is more sensitive than the PEG-dextran method in viral acid nucleic recovery from surface water samples. Better results were obtained pre-filtering samples with Sartolab® P20 and extracting the nucleic acids with undiluted silica, rather than diluted as required by the standard protocol. The proposed method will be used for the monitoring of surface waters in the Milan area.

Possible intraindividual evolution of SARS-CoV-2 in nasopharyngeal and anal swab in an octogenarian: a case report

Introduction

COVID-19 is an emerging infectious disease that remains to be further investigated.

Case report

Here, we describe a case of COVID-19 in an octogenarian woman with comorbidities who slowly recovered during hospitalization, but died due to sudden cardiac death after 2 weeks of hospitalization. Her nasopharyngeal and anal swabs returned positive for SARS-CoV-2 by RT-PCR on day 7 of hospitalization. The NGS showed possible intraindividual evolution of virus. The sample from the nasopharyngeal swab yielded a B.1470 variant classified as clade GH. This variant showed mutation in the spike gene D614G; N gene; NS3 gene; NSP2 gene and NSP12 gene. The sample from the anal swab showed similar mutation but with additional point mutation in spike gene S12F and was classified as B.1.465 variant.

Conclusions

The possibility of the gastrointestinal tract that served as reservoir for virus mutation accumulation should also be considered and the potential impact of viral fecal transmission in the environment should be further investigated.

Monitoring COVID-19 spread in Prague local neighborhoods based on the presence of SARS-CoV-2 RNA in wastewater collected throughout the sewer network

Many reports have documented that the presence of SARS-CoV-2 RNA in the influents of municipal wastewater treatment plants (WWTP) correlates with the actual epidemic situation in a given city. However, few data have been reported thus far on measurements upstream of WWTPs, i.e. throughout the sewer network. In this study, the monitoring of the presence of SARS-CoV-2 RNA in Prague wastewater was carried out at selected locations of the Prague sewer network from August 2020 through May 2021. Various locations such as residential areas of various sizes, hospitals, city center areas, student dormitories, transportation hubs (airport, bus terminal), and commercial areas were monitored together with four of the main Prague sewers. The presence of SARS-CoV-2 RNA was determined by reverse transcription - multiplex quantitative polymerase chain reaction (RT-mqPCR) after the precipitation of nucleic acids with PEG 8,000 and RNA isolation with TRIzol™ Reagent. The number of copies of the gene encoding SARS-CoV-2 nucleocapsid (N1) per liter of wastewater was compared with the number of officially registered COVID-19 cases in Prague. Although the data obtained by sampling wastewater from the major Prague sewers were more consistent than those obtained from the small sewers, the correlation between wastewater-based and clinical-testing data was also good for the residential areas with more than 7,000 registered inhabitants. It was shown that monitoring SARS-CoV-2 RNA in wastewater sampled from small sewers could identify isolated occurrences of COVID-19-positive cases in local neighborhoods. This can be very valuable while tracking COVID-19 hotspots within large cities.

Monitoring COVID-19 spread in Prague local neighborhoods based on the presence of SARS-CoV-2 RNA in wastewater collected throughout the sewer network

Many reports have documented that the presence of SARS-CoV-2 RNA in the influents of municipal wastewater treatment plants (WWTP) correlates with the actual epidemic situation in a given city. However, few data have been reported thus far on measurements upstream of WWTPs, i.e. throughout the sewer network. In this study, the monitoring of the presence of SARS-CoV-2 RNA in Prague wastewater was carried out at selected locations of the Prague sewer network from August 2020 through May 2021. Various locations such as residential areas of various sizes, hospitals, city center areas, student dormitories, transportation hubs (airport, bus terminal), and commercial areas were monitored together with four of the main Prague sewers. The presence of SARS-CoV-2 RNA was determined by reverse transcription - multiplex quantitative polymerase chain reaction (RT-mqPCR) after the precipitation of nucleic acids with PEG 8,000 and RNA isolation with TRIzol™ Reagent. The number of copies of the gene encoding SARS-CoV-2 nucleocapsid (N1) per liter of wastewater was compared with the number of officially registered COVID-19 cases in Prague. Although the data obtained by sampling wastewater from the major Prague sewers were more consistent than those obtained from the small sewers, the correlation between wastewater-based and clinical-testing data was also good for the residential areas with more than 7,000 registered inhabitants. It was shown that monitoring SARS-CoV-2 RNA in wastewater sampled from small sewers could identify isolated occurrences of COVID-19-positive cases in local neighborhoods. This can be very valuable while tracking COVID-19 hotspots within large cities.

Successful Bacterial Engraftment Identified by Next-Generation Sequencing Predicts Success of Fecal Microbiota Transplant for Clostridioides difficile

Background

The effectiveness of fecal microbiota transplantation (FMT), a treatment for Clostridioides difficile infection (CDI), is dependent on successful engraftment (incorporation) of donor stool. We present a method for evaluating engraftment success based on next-generation sequencing (NGS)-based profiling of bacterial strains present in donor and recipient stool, and we suggest its potential to guide treatment decisions.

Methods

Bacterial strains in stool samples from three patients from the clinic and one donor were analyzed via NGS and metagenomic sequencing, before and 1 month after FMT for CDI. The similarity of strains present was assessed via relative abundance, principal component analysis, Shannon and Simpson diversity indexes, and Bray-Curtis dissimilarity matrix. A positive outcome was successful engraftment, where the post-FMT sample closely resembled that of the donor and CDI was cured.

Results

Patients (Pts.) 1 and 2, but not Pt. 3’s stool samples closely resembled the donor specimen post-FMT. Noteworthy, Pt. 3 pre-FMT sample was less similar to the donor than that of Pts. 1 and 2. All methods of assessing similarity and dissimilarity used yielded virtually identical conclusions. Pts. 1 and 2 which closely resembled donor specimen, eradicated CDI giving a surrogate objective measure of engraftment.

Conclusions

Success of engraftment in FMT can be assessed using NGS and metagenomic analysis and parallels success in curing CDI of the microbiome. The statistical methods we present here are reliable and consistent for such purposes. The dissimilarity of Pt. 3 to the donor combined with the failure of engraftment and failure to cure CDI in Pt. 3 suggests that FMT success may be predictable by comparing pre-FMT samples to donor. There is no clinical trial registry listing this study.

Gastrointestinal symptoms in COVID-19 could be associated with severe lung involvement and increased readmission rates

Introduction

SARS-CoV-2 virus manifests itself with primary lung damage but also has intestinal involvement. In this study, we aimed to investigate the frequency of gastrointestinal symptoms (GIS) and the relationship of GIS with readmission to the hospital within 30 days in SARS-CoV-2 infected patients who were hospitalized in a specified pandemic hospital.

Materials and Methods

Symptomatic patients diagnosed with rapid antibody positivity with real-time polymerase chain reaction and typical thorax computed tomography findings were included in this retrospective cohort observational study. Demographic and clinical data were obtained from electronic medical records. Hospital-associated GIS were considered as experiencing at least one of the GIS such as gas, bloating, diarrhea, and constipation developing within72 h after hospital admission.

Results

The mean age of the patients was 58 ± 14.4 years and 60.7% were men. 82% of hospitalizations were a moderate and severe disease. 71.4% of patients without GIS had at least one of the GIS after hospitalization. As the severity of the disease increased, the frequency of the severity of gastrointestinal symptom increased. GIS bowel disorders were more prominent in patients with moderate and severe disease. Antibiotic and specific treatment (anti-Il-1, anti-Il-6) contributed to the occurrence of gastrointestinal symptom in SARS-CoV-2 inpatients.

Conclusion

According to our observations of the second wave of the pandemic, the presence, frequency, and severity of gastrointestinal symptom in inpatient is associated with severity of lung disease and increased readmission rate after discharge.

Role of gastrointestinal system on transmission and pathogenesis of SARS-CoV-2

Coronavirus disease 2019 (COVID-19) continues to pose a significant threat to global health. Primary prevention remains as a major strategy against the pandemic. Current evidence proves that aerosol and droplet-based routes are the main means of transmission of COVID-19 but other ways should be sought in order to prevent possible collateral transmission. The gastrointestinal system may be one such route. Angiotensin converting enzyme 2 is the target entry receptor for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that is abundantly expressed in the gastrointestinal tract. SARS-CoV-2 is able to infect human enterocytes similar to severe acute respiratory syndrome and Middle Eastern respiratory syndrome. Herein this review, we discuss the current knowledge regarding the role of gastrointestinal transmission in transmission and pathophysiology of COVID-19.

Minimally Invasive Autopsy Practice in COVID-19 Cases: Biosafety and Findings

Postmortem studies are crucial for providing insight into emergent diseases. However, a complete autopsy is frequently not feasible in highly transmissible diseases due to biohazard challenges. Minimally invasive autopsy (MIA) is a needle-based approach aimed at collecting samples of key organs without opening the body, which may be a valid alternative in these cases. We aimed to: (a) provide biosafety guidelines for conducting MIAs in COVID-19 cases, (b) compare the performance of MIA versus complete autopsy, and (c) evaluate the safety of the procedure. Between October and December 2020, MIAs were conducted in six deceased patients with PCR-confirmed COVID-19, in a basic autopsy room, with reinforced personal protective equipment. Samples from the lungs and key organs were successfully obtained in all cases. A complete autopsy was performed on the same body immediately after the MIA. The diagnoses of the MIA matched those of the complete autopsy. In four patients, COVID-19 was the main cause of death, being responsible for the different stages of diffuse alveolar damage. No COVID-19 infection was detected in the personnel performing the MIAs or complete autopsies. In conclusion, MIA might be a feasible, adequate and safe alternative for cause of death investigation in COVID-19 cases.