Fecal Shedding of SARS-CoV-2 and Its Potential Role in Person-To-Person Transmission and the Environment-Based Spread of COVID-19

The recent detection of SARS-CoV-2 RNA in feces has led to speculation that it can be transmitted via the fecal-oral/ocular route. This review aims to critically evaluate the incidence of gastrointestinal (GI) symptoms, the quantity and infectivity of SARS-CoV-2 in feces and urine, and whether these pose an infection risk in sanitary settings, sewage networks, wastewater treatment plants, and the wider environment (e.g. rivers, lakes and marine waters). Overall, severe GI dysfunction is only evident in a small number of COVID-19 cases, with 11 ± 2% exhibiting diarrhea and 12 ± 3% exhibiting vomiting and nausea. In addition to these cases, SARS-CoV-2 RNA can be detected in feces from some asymptomatic, mildly- and pre-symptomatic individuals. Fecal shedding of the virus peaks in the symptomatic period and can persist for several weeks, but with declining abundances in the post-symptomatic phase. SARS-CoV-2 RNA is occasionally detected in urine, but reports in fecal samples are more frequent. The abundance of the virus genetic material in both urine (ca. 102-105 gc/ml) and feces (ca. 102-107 gc/ml) is much lower than in nasopharyngeal fluids (ca. 105-1011 gc/ml). There is strong evidence of multiplication of SARS-CoV-2 in the GI tract and infectious virus has occasionally been recovered from both urine and stool samples. The level and infectious capability of SARS-CoV-2 in vomit remain unknown. In comparison to enteric viruses transmitted via the fecal-oral route (e.g. norovirus, adenovirus), the likelihood of SARS-CoV-2 being transmitted via feces or urine appears lower due to the lower relative amounts of virus present in feces/urine. The biggest risk of transmission will occur in clinical and care home settings where secondary handling of people and urine/fecal matter occurs. In addition, while SARS-CoV-2 RNA genetic material can be detected by in wastewater, this signal is greatly reduced by conventional treatment. Our analysis also suggests the likelihood of infection due to contact with sewage-contaminated water (e.g. swimming, surfing, angling) or food (e.g. salads, shellfish) is extremely low or negligible based on very low predicted abundances and limited environmental survival of SARS-CoV-2. These conclusions are corroborated by the fact that over eight million global cases of COVID-19 have occurred, but exposure to feces or wastewater has never been implicated as a transmission vector.

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An Animal Model to Study Klebsiella pneumoniae Gastro-Intestinal Colonization and Host-to-Host Transmission

10.1101/2020.02.04.934893 ◽

2020 ◽

Author(s):

Taylor M. Young ◽

Andrew S. Bray ◽

Ravinder K. Nagpal ◽

David L. Caudell ◽

Hariom Yadav ◽

...

Keyword(s):

Klebsiella Pneumoniae ◽

Close Contact ◽

Epidemiological Studies ◽

Transmission Efficiency ◽

Oral Route ◽

Human Infection ◽

Drug Resistant ◽

Gi Tract ◽

Fecal Shedding ◽

Immunocompetent Mice

AbstractAn important yet poorly understood facet in the life cycle of a successful pathogen is the host-to-host transmission. Hospital-acquired infections (HAI) resulting from the transmission of drug-resistant pathogens affect hundreds of millions of patients worldwide. Klebsiella pneumoniae (Kpn), a gram-negative bacterium, is notorious for causing HAI, with many of these infections difficult to treat as Kpn has become multi-drug resistant. Epidemiological studies suggest that Kpn host-to-host transmission requires close contact and generally occurs through the fecal-oral route. Herein, we describe a murine model that can be utilized to study mucosal (oropharynx and gastrointestinal [GI]) colonization, shedding within feces, and transmission of Kpn through the fecal-oral route. Using an oral route of inoculation, and fecal shedding as a marker for GI colonization, we show that Kpn can asymptomatically colonize the GI tract of immunocompetent mice, and modifies the host GI microbiota. Colonization density within the GI tract and levels of shedding in the feces differed among the clinical isolates tested. A hypervirulent Kpn isolate was able to translocate from the GI tract and cause hepatic infection that mimicked the route of human infection. Expression of the capsule was required for colonization and, in turn, robust shedding. Furthermore, Kpn carrier mice were able to transmit to uninfected cohabitating mice. Lastly, treatment with antibiotics led to changes in the host microbiota and development of a transient super-shedder phenotype, which enhanced transmission efficiency. Thus, this model can be used to determine the contribution of host and bacterial factors towards Kpn dissemination.

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The Spectre of SARS-CoV-2 in the Ambient Urban Natural Water in Ahmedabad and Guwahati: A Tale of Two Cities

10.1101/2021.06.12.21258829 ◽

2021 ◽

Author(s):

Manish Kumar ◽

Payal Mazumder ◽

Jyoti Prakash Deka ◽

Vaibhav Srivastava ◽

Chandan Mahanta ◽

...

Keyword(s):

Surface Water ◽

Natural Waters ◽

Genetic Material ◽

Oral Route ◽

N Gene ◽

Western India ◽

High Concentration ◽

Fecal Matter ◽

Middle Income ◽

S Gene

COVID-19 positive patients can egest live SARS-CoV-2 virus through fecal matter and urine, raising concerns about viral transmission through the fecal-oral route and/or contaminated aerosolized water. These worries are heightened in many low and middle-income nations, where raw sewage is often dumped into surface waterways and open defecation betide. In this manuscript we attempt to discern the presence of SARS-CoV-2 genetic material (ORF-1ab, N and S genes) in two urban cities of India viz., Ahmedabad, in western India with ~12 WWTPs and Guwahati, in the northeast of the country with no such plants. 100% and 20% of the surface water samples had detectable SARSCoV-2 RNA load in Ahmedabad and Gandhinagar, respectively. N-gene>S-gene>ORF-1ab-gene were readily detected in the surface water of Ahmedabad, whereas, no such significant trend was found in the case of Guwahati. The high concentration of gene (ORF-1ab 800 copies/L for Sabarmati river, Ahmedabad and S-gene 565 copies/L for Bharalu urban river, Guwahati) found in natural waters indicates low sanitation and have various health and ecological consequences that should be investigated further.

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SARS-CoV-2-associated gastrointestinal and liver diseases: what is known and what is needed to explore

Egyptian Liver Journal ◽

10.1186/s43066-021-00123-6 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Dina Sweed ◽

Eman Abdelsameea ◽

Esraa A. Khalifa ◽

Heba Abdallah ◽

Heba Moaz ◽

...

Keyword(s):

English Language ◽

Data Extraction ◽

Oral Route ◽

Main Body ◽

Disease Manifestation ◽

Gi Symptoms ◽

Septic Focus ◽

Pubmed Search ◽

Risk Patients ◽

Respiratory Droplets

Abstract Background The pandemic of COVID19 which is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was first described in China as an unexplained pneumonia transmitted by respiratory droplets. Gastrointestinal (GI) and liver injury associated with SARS-CoV-2 infection were reported as an early or sole disease manifestation, mainly outside China. The exact mechanism and incidence of GI and liver involvement are not well elucidated. Main body We conducted a PubMed search for all articles written in the English language about SARS-CoV-2 affecting the GI and liver. Following data extraction, 590 articles were selected. In addition to respiratory droplets, SARS-CoV-2 may reach the GI system through the fecal-oral route, saliva, and swallowing of nasopharyngeal fluids, while breastmilk and blood transmission were not implicated. Moreover, GI infection may act as a septic focus for viral persistence and transmission to the liver, appendix, and brain. In addition to the direct viral cytopathic effect, the mechanism of injury is multifactorial and is related to genetic and demographic variations. The most frequently reported GI symptoms are diarrhea, nausea, vomiting, abdominal pain, and bleeding. However, liver infection is generally discovered during laboratory testing or a post-mortem. Radiological imaging is the gold standard in diagnosing COVID-19 patients and contributes to understanding the mechanism of extra-thoracic involvement. Medications should be prescribed with caution, especially in chronic GI and liver patients. Conclusion GI manifestations are common in COVID-19 patients. Special care should be paid for high-risk patients, older males, and those with background liver disease.

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Carbohydrate Scaffolds for the Study of the Autism-associated Bacterium, Clostridium bolteae

Current Medicinal Chemistry ◽

10.2174/0929867326666190225164527 ◽

2019 ◽

Vol 26 (35) ◽

pp. 6341-6348 ◽

Cited By ~ 4

Author(s):

Brittany Pequegnat ◽

Mario A. Monteiro

Keyword(s):

Autism Spectrum ◽

Diagnostic Tools ◽

Gi Tract ◽

Autism Symptoms ◽

Number Of Children ◽

Stool Samples ◽

Brain Connection ◽

Surface Carbohydrates ◽

Clostridium Bolteae

A large number of children in the autism spectrum disorder suffer from gastrointestinal (GI) conditions, such as constipation and diarrhea. Clostridium bolteae is a part of a set of pathogens being regularly detected in the stool samples of hosts affected by GI and autism symptoms. Accompanying studies have pointed out the possibility that such microbes affect behaviour through the production of neurotoxic metabolites in a so-called, gut-brain connection. As an extension of our Clostridium difficile polysaccharide (PS)-based vaccine research, we engaged in the discovery of C. bolteae surface carbohydrates. So far, studies revealed that C. bolteae produces a specific immunogenic PS capsule comprised of disaccharide repeating blocks of mannose (Manp) and rhamnose (Rhap) units: α-D-Manp-(1→[-4)-β-D-Rhap- (1→3)-α-D-Manp-(1→]n. For vaccinology and further immunogenic experiments, a method to produce C. bolteae PS conjugates has been developed, along with the chemical syntheses of the PS non-reducing end linkage, with D-Rha or L-Rha, α-D-Manp-(1→4)-α-D-Rhap- (1→O(CH2)5NH2 and α-D-Manp-(1→4)-α-L-Rhap-(1→O(CH2)5NH2, equipped with an aminopentyl linker at the reducing end for conjugation purposes. The discovery of C. bolteae PS immunogen opens the door to the creation of non-evasive diagnostic tools to evaluate the frequency and role of this microbe in autistic subjects and to a vaccine to reduce colonization levels in the GI tract, thus impeding the concentration of neurotoxins.

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Comparison of Two DNA Extraction Methods and Two PCRs for Detection of Echinococcus multilocularis in the Stool Samples of Naturally Infected Red Foxes

Animals ◽

10.3390/ani10122381 ◽

2020 ◽

Vol 10 (12) ◽

pp. 2381

Author(s):

Katarzyna Skrzypek ◽

Jacek Karamon ◽

Małgorzata Samorek-Pieróg ◽

Joanna Dąbrowska ◽

Maciej Kochanowski ◽

...

Keyword(s):

Positive Result ◽

Multiplex Pcr ◽

Dna Extraction ◽

Echinococcus Multilocularis ◽

Nested Pcr ◽

Genetic Material ◽

Extraction Methods ◽

Red Foxes ◽

Stool Samples ◽

Positive Results

(1) Background: Due to the increasing distribution of Echinococcus multilocularis infections in final hosts, epidemiological investigations are important for recognizing the spreading pattern of this parasite and also to estimate risk infection for humans. (2) Methods: Investigations were conducted with two commercial kits dedicated for DNA extraction from feces: ZR Fecal DNA Mini Prep (Zymo Research, Freiburg, Germany) and QIAamp FAST DNA Stool Mini Kit (Qiagen, Hilden, Germany) (marked as Z and Q), together with two common PCR protocols (nested PCR and multiplex PCR). The goal was to compare their efficiency in detecting the genetic material of E. multilocularis in the samples of feces. Stool samples from red foxes were collected in a highly endemic area in Poland. Sedimentation and counting technique (SCT) was used as a reference method. (3) Results: From 48 samples, 35 were positive in SCT. Further investigations showed that 40.0% of samples (from those with SCT positive result) after Z-DNA extraction and 45.7% after Q-DNA extraction gave positive results in nested PCR. In multiplex PCR, positive results were obtained in 54.3% of samples after Z isolation and 48.6% of samples after Q. Additionally, one sample that resulted in being negative in SCT gave a positive result in PCR. The number of worms detected in the intestines had no influence on PCR results. (4) Conclusions: Both of the extraction methods showed similar efficiency in DNA isolation and dealing with inhibitors; however, they showed relatively low sensitivity. This was probably caused by degradation of genetic material in the field-collected samples.

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Antibiotic Residue in the Aquatic Environment: Status in Africa

Open Chemistry ◽

10.1515/chem-2018-0099 ◽

2018 ◽

Vol 16 (1) ◽

pp. 890-903 ◽

Cited By ~ 10

Author(s):

A.C. Faleye ◽

A.A. Adegoke ◽

K. Ramluckan ◽

Faizal Bux ◽

T. A. Stenström

Keyword(s):

Antibiotic Resistance ◽

Surface Water ◽

Aquatic Environment ◽

Human Population ◽

Potable Water ◽

Wastewater Treatment Plants ◽

Fecal Matter ◽

Sanitation Systems ◽

Poor Nutrition ◽

Antibiotic Residue

AbstractInformation on the presence of antibiotics is sparse for all types of water in Africa, including groundwater, surface water, effluent of wastewater treatment plants (WWTPs) and municipal potable water. With the relatively high sales of different antibiotics to treat infectious diseases in the human population of Africa, the residual of the antibiotics is bound to be released through excretion via urine or fecal matter in parallel to the high sales. This article reviews the published analysis on the occurrence of antibiotics in the environment particularly in the aquatic environment in some countries in Africa. In general, sulfamethoxazole was the most commonly detected in Africa surface water (with eight reports from four countries) at a concentration range of 0.00027 – 39 μgL-1. Wastewater analysis is believed to give an early warning for preventing epidemics. Thus, we discuss the associated level of antibiotic resistance to some prevalent diseases in Africa whose aetiological agents can develop antibiotic resistance due to exposure to antibiotic residue in water. This is important because of rising population of immuno-deficient African residents ravaged by HIV/AIDS, poor nutrition and less efficient sanitation systems.

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P851 Effects of conservation time on the diversity and relative abundance of intestinal microbiome in samples of faecal matters

Journal of Crohn s and Colitis ◽

10.1093/ecco-jcc/jjz203.979 ◽

2020 ◽

Vol 14 (Supplement_1) ◽

pp. S655-S655

Author(s):

M León F ◽

C A Nieto ◽

Z Corredor ◽

C Flórez-Sarmiento ◽

V Parra-Izquierdo ◽

...

Keyword(s):

Dna Extraction ◽

Relative Abundance ◽

High Reliability ◽

Genetic Material ◽

Variable Region ◽

Important Variable ◽

Intestinal Microbiome ◽

Three Samples ◽

Stool Samples ◽

Changes Over Time

Abstract Background Given the complexity and diversity of the intestinal microbiome, there is a technical challenge of finding the best way to study the factors that affect the quality of the sample to obtain results in a precise an complete way. Objective To establish the effect of storage time under constant cryopreservation conditions (−20°C) in stool samples for the study of the gastrointestinal microbiome Methods A sample of stool was distributed in 3 fractions (1, 2 and 3). Time 0 without cryopreservation and immediate DNA extraction (1). The samples of 15 (2) and 30 (3) days were cryopreserved at −20°C before the extraction of the genetic material. After ultracentrifugation at 4 degrees Celsius, the precipitate was subjected to enzymatic and mechanical lysis to obtain the total DNA. The DNA quality was evaluated techniques to ensure the quality and concentration of genetic material. Once the DNA of the three samples was obtained, they were subjected to the latest generation of a variable region of the 16S gene, using MiSeq technology (Illuminates). Data in relative abundances and frequencies were recorded. Project supported by the Administrative Department of Science, Technology and Innovation-Colciencias Health Call 2017, Code 130877757442 Results About 140 thousand readings were obtained for samples 1 (day 0) and 2 (day 15) and 160 thousand for sample 3 (day 30), with a reading quality Q20% between 97 and 98 and Q30% around 94, indicating a high-reliability value for each of the samples. Regarding the classification from the Operating Taxonomic Unit (OTU), 119, 99 and 106 were reported for samples 1, 2 and 3, respectively. The data obtained revealed changes over time at the level of the main edges reported for normal microbiome (Bacteroidetes, Firmicutes, Actinobacteria) between 1 and 2 vs. sample 3. For Firmicutes and Actinobacteria, decreases in abundance of 34% were observed (samples 1 and 2) at 20% for Firmicutes in sample 3 and from 4% (samples 1 and 2) to 0.8% (sample 3) for Actinobacteria. On the contrary, Bacteroidetes presented an increase in its abundance from 58% (Samples 1 and 2) to 76% (sample 3). The Proteobacterium edge did not show significant changes in its abundance Conclusion It was possible to demonstrate that the cryopreservation time before DNA extraction is an important variable that influences the percentage and integrity of the microbiota from faecal matter. Confirming that the maximum reliable shelf life at −20° in stool samples is up to 15 days, suggesting that for longer storage the temperature decrease up to −80° should be taken into account to maintain stability in the results of relative abundance and bacterial diversity

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Animal Model To Study Klebsiella pneumoniae Gastrointestinal Colonization and Host-to-Host Transmission

Infection and Immunity ◽

10.1128/iai.00071-20 ◽

2020 ◽

Vol 88 (11) ◽

Author(s):

Taylor M. Young ◽

Andrew S. Bray ◽

Ravinder K. Nagpal ◽

David L. Caudell ◽

Hariom Yadav ◽

...

Keyword(s):

Klebsiella Pneumoniae ◽

Close Contact ◽

Epidemiological Studies ◽

Multidrug Resistant ◽

Transmission Efficiency ◽

Oral Route ◽

Human Infection ◽

Gi Tract ◽

Content Type ◽

Immunocompetent Mice

ABSTRACT An important yet poorly understood facet of the life cycle of a successful pathogen is host-to-host transmission. Hospital-acquired infections (HAI) resulting from the transmission of drug-resistant pathogens affect hundreds of millions of patients worldwide. Klebsiella pneumoniae, a Gram-negative bacterium, is notorious for causing HAI, with many of these infections difficult to treat, as K. pneumoniae has become multidrug resistant. Epidemiological studies suggest that K. pneumoniae host-to-host transmission requires close contact and generally occurs through the fecal-oral route. Here, we describe a murine model that can be utilized to study mucosal (oropharynx and gastrointestinal [GI]) colonization, shedding within feces, and transmission of K. pneumoniae through the fecal-oral route. Using an oral route of inoculation, and fecal shedding as a marker for GI colonization, we showed that K. pneumoniae can asymptomatically colonize the GI tract in immunocompetent mice and modifies the host GI microbiota. Colonization density within the GI tract and levels of shedding in the feces differed among the clinical isolates tested. A hypervirulent K. pneumoniae isolate was able to translocate from the GI tract and cause hepatic infection that mimicked the route of human infection. Expression of the capsule was required for colonization and, in turn, robust shedding. Furthermore, K. pneumoniae carrier mice were able to transmit to uninfected cohabitating mice. Lastly, treatment with antibiotics led to changes in the host microbiota and development of a transient supershedder phenotype, which enhanced transmission efficiency. Thus, this model can be used to determine the contribution of host and bacterial factors toward K. pneumoniae dissemination.

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Gastrointestinal Involvement in Mantle Cell Lymphoma (MCL). A Prospective Clinical, Endoscopical, Pathological and Molecular Study.

Blood ◽

10.1182/blood.v106.11.4665.4665 ◽

2005 ◽

Vol 106 (11) ◽

pp. 4665-4665

Author(s):

Antonio Salar ◽

Nuria Juanpere ◽

Eva Gonzalez-Barca ◽

Beatriz Bellosillo ◽

Blanca Espinet ◽

...

Keyword(s):

Cyclin D1 ◽

Molecular Study ◽

Normal Mucosa ◽

Microscopic Level ◽

Gi Tract ◽

Upper Gi ◽

Multiple Biopsies ◽

Gi Symptoms ◽

Lower Endoscopy ◽

Almost All

Abstract Objective: to investigate the clinical, endoscopical, microscopical and molecular involvement of the GI tract in a prospective series of MCL. Methods: 13 patients with MCL have been prospectively and consecutively entered in a staging workup that included upper and lower endoscopy of the GI tract. Multiple biopsies of the stomach and colon were taken from pathologic mucosa and also from macroscopically normal mucosa. Specimens were assessed with immunohistochemistry (IHC), FISH and PCR. Results: Only 1 patient presented with GI symptoms at diagnosis. Endoscopy: Upper GI: abnormal mucosa in 5 cases (38%); Lower GI: abnormal mucosa in 6 cases (45%): mild colitis in 1, multiple micropolyps in 3, a large polyp and multiple micropolyps in 1 and three large polyps with normal mucosa in 1. As a whole, 9 patients (70%) had upper or lower endoscopic findings. Pathology: 10 cases (77%) had microscopic infiltration by MCL of the upper GI tract and 10 cases (77%) of the lower GI tract. As a whole, all but one patient (92%) were found to have microscopic infiltration of the GI tract. All positive cases for CD20 and CD5 were positive for cyclin D1. The PCR product showed a clear monoclonal peak in 12 out of 19 samples, giving a sensitivity of 63.5% compared with IHC. FISH was positive in 7 out of 11 samples (sensitivity of 64% compared with IHC). All but one case with endoscopic abnormalities had GI microscopic infiltration by MCL and 67% of cases with normal endoscopy were found to have GI tract infiltration by MCL. Conclusions: In our series, GI involvement by MCL was detected in almost all patients. All patients with endoscopic abnormalities had infiltration by MCL at the microscopic level. In 2/3 of the patients with normal endoscopy, GI tract involvement could be demonstrated at the microscopic level. IHC with cyclin D1 was more efficient than FISH and PCR as a diagnostic tool in this setting.

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INTERACTION OF THE SYMBIOTIC MICROBIOTA OF THE GASTRO-INTESTINAL TRACT WITH THE NERVOUS SYSTEM OF THE HOST ORGANISM

Physical and rehabilitation medicine, medical rehabilitation ◽

10.36425/2658-6843-19193 ◽

2019 ◽

Vol 1 (2) ◽

pp. 90-100

Author(s):

A V Oleskin

Keyword(s):

Nervous System ◽

Intestinal Tract ◽

Distal Part ◽

Human Organism ◽

Gi Tract ◽

Physical And Mental Health ◽

Gi Symptoms ◽

Gastro Intestinal Tract ◽

Symbiotic Microbiota

Symbiotic microorganisms inhabit a wide variety of niches in the human organism. Of paramount importance is the microbiota of the gastro-intestinal (GI) tract, especially of its distal part (the colon). Bidirectional signal exchange proceeds within the microbiota-host system, and diverse microbial metabolites modify the functions of the nervous system via metabolic, genetic, and neuroendocrine pathways. Increasing attention is currently given to the role of the GI microbiota in terms of the host's physical and mental health; therefore, it has been suggested to replace the widely used term gut-brain axis with the new term microbiota-gut-brain axis. The GI microbiota directly interacts with the enteric nervous system (ENS) that represents a partly autonomous subdivision of the nervous system. An important role is also played by the GI tract-innervating vagus nerve. In addition, the influence of the microbiota on the nervous system can be mediated by the immune system. The microbiota impact on the nervous system of the host results in significant alterations in the host's behavior, mood, and even taste. In the literature, there is evidence that neurological and psychological diseases are linked to microecological disorders (dysbioses) in the GI tract. In particular, dysbioses with manifest GI symptoms are often accompanied by serious brain problems.

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