scholarly journals Increase of SARS-CoV-2 RNA load in faecal samples prompts for rethinking of SARS-CoV-2 biology and COVID-19 epidemiology

F1000Research ◽  
2021 ◽  
Vol 10 ◽  
pp. 370
Author(s):  
Mauro Petrillo ◽  
Carlo Brogna ◽  
Simone Cristoni ◽  
Maddalena Querci ◽  
Ornella Piazza ◽  
...  

Background Scientific evidence for the involvement of human microbiota in the development of COVID-19 disease has been reported recently. SARS-CoV-2 RNA presence in human faecal samples and SARS-CoV-2 activity in faeces from COVID-19 patients have been observed. Methods Starting from these observations, an experimental design was developed to cultivate in vitro faecal microbiota from infected individuals, to monitor the presence of SARS-CoV-2, and to collect data on the relationship between faecal bacteria and the virus. Results Our results indicate that SARS-CoV-2 replicates in vitro in bacterial growth medium, that the viral replication follows bacterial growth and it is influenced by the administration of specific antibiotics. SARS-CoV-2-related peptides have been detected in 30-day bacterial cultures and characterised. Discussion Our observations are compatible with a ‘bacteriophage-like’ behaviour of SARS-CoV-2, which, to our knowledge has not been observed or described before. These results are unexpected and hint towards a novel hypothesis on the biology of SARS-CoV-2 and on the COVID-19 epidemiology. The discovery of possible new modes of action of SARS-CoV-2 has far-reaching implications for the prevention and the treatment of the disease.

F1000Research ◽  
2021 ◽  
Vol 10 ◽  
pp. 370
Author(s):  
Mauro Petrillo ◽  
Carlo Brogna ◽  
Simone Cristoni ◽  
Maddalena Querci ◽  
Ornella Piazza ◽  
...  

Background Scientific evidence for the involvement of human microbiota in the development of COVID-19 disease has been reported recently. SARS-CoV-2 RNA presence in human faecal samples and SARS-CoV-2 activity in faeces from COVID-19 patients have been observed. Methods Starting from these observations, an experimental design was developed to cultivate in vitro faecal microbiota from infected individuals, to monitor the presence of SARS-CoV-2, and to collect data on the relationship between faecal bacteria and the virus. Results Our results indicate that SARS-CoV-2 replicates in vitro in bacterial growth medium, that the viral replication follows bacterial growth and it is influenced by the administration of specific antibiotics. SARS-CoV-2-related peptides have been detected in 30-day bacterial cultures and characterised. Discussion Our observations are compatible with a ‘bacteriophage-like’ behaviour of SARS-CoV-2, which, to our knowledge has not been observed or described before. These results are unexpected and hint towards a novel hypothesis on the biology of SARS-CoV-2 and on the COVID-19 epidemiology. The discovery of possible new modes of action of SARS-CoV-2 has far-reaching implications for the prevention and the treatment of the disease.


F1000Research ◽  
2021 ◽  
Vol 10 ◽  
pp. 370
Author(s):  
Mauro Petrillo ◽  
Carlo Brogna ◽  
Simone Cristoni ◽  
Maddalena Querci ◽  
Ornella Piazza ◽  
...  

Background Scientific evidence for the involvement of human microbiota in the development of COVID-19 disease has been reported recently. SARS-CoV-2 RNA presence in human faecal samples and SARS-CoV-2 activity in faeces from COVID-19 patients have been observed. Methods Starting from these observations, an experimental design was developed to cultivate in vitro faecal microbiota from infected individuals, to monitor the presence of SARS-CoV-2, and to collect data on the relationship between faecal bacteria and the virus. Results Our results indicate that SARS-CoV-2 replicates in vitro in bacterial growth medium, that the viral replication follows bacterial growth and it is influenced by the administration of specific antibiotics. SARS-CoV-2-related peptides have been detected in 30-day bacterial cultures and characterised. Discussion Our observations are compatible with a ‘bacteriophage-like’ behaviour of SARS-CoV-2, which, to our knowledge has not been observed or described before. These results are unexpected and hint towards a novel hypothesis on the biology of SARS-CoV-2 and on the COVID-19 epidemiology. The discovery of possible new modes of action of SARS-CoV-2 has far-reaching implications for the prevention and the treatment of the disease.


2018 ◽  
Vol 9 (1) ◽  
pp. 21-34 ◽  
Author(s):  
K. Adamberg ◽  
K. Kolk ◽  
M. Jaagura ◽  
R. Vilu ◽  
S. Adamberg

The metabolic activity of colon microbiota is specifically affected by fibres with various monomer compositions, degree of polymerisation and branching. The supply of a variety of dietary fibres assures the diversity of gut microbial communities considered important for the well-being of the host. The aim of this study was to compare the impact of different oligo- and polysaccharides (galacto- and fructooligosaccharides, resistant starch, levan, inulin, arabinogalactan, xylan, pectin and chitin), and a glycoprotein mucin on the growth and metabolism of faecal microbiota in vitro by using isothermal microcalorimetry (IMC). Faecal samples from healthy donors were incubated in a phosphate-buffered defined medium with or without supplementation of a single substrate. The generation of heat was followed on-line, microbiota composition (V3-V4 region of the 16S rRNA using Illumina MiSeq v2) and concentrations of metabolites (HPLC) were determined at the end of growth. The multiauxic power-time curves obtained were substrate-specific. More than 70% of all substrates except chitin were fermented by faecal microbiota with total heat generation of up to 8 J/ml. The final metabolite patterns were in accordance with the microbiota changes. For arabinogalactan, xylan and levan, the fibre-affected distribution of bacterial taxa showed clear similarities (e.g. increase of Bacteroides ovatus and decrease of Bifidobacterium adolescentis). The formation of propionic acid, an important colon metabolite, was enhanced by arabinogalactan, xylan and mucin but not by galacto- and fructooligosaccharides or inulin. Mucin fermentation resulted in acetate, propionate and butyrate production in ratios previously observed for faecal samples, indicating that mucins may serve as major substrates for colon microbial population. IMC combined with analytical methods was shown to be an effective method for screening the impact of specific dietary fibres on functional changes in faecal microbiota.


2011 ◽  
Vol 107 (10) ◽  
pp. 1466-1475 ◽  
Author(s):  
Gemma E. Walton ◽  
Ellen G. H. M. van den Heuvel ◽  
Marit H. W. Kosters ◽  
Robert A. Rastall ◽  
Kieran M. Tuohy ◽  
...  

Faecal microbial changes associated with ageing include reduced bifidobacteria numbers. These changes coincide with an increased risk of disease development. Prebiotics have been observed to increase bifidobacteria numbers within humans. The present study aimed to determine if prebiotic galacto-oligosaccharides (GOS) could benefit a population of men and women of 50 years and above, through modulation of faecal microbiota, fermentation characteristics and faecal water genotoxicity. A total of thirty-seven volunteers completed this randomised, double-blind, placebo-controlled crossover trial. The treatments – juice containing 4 g GOS and placebo – were consumed twice daily for 3 weeks, preceded by 3-week washout periods. To study the effect of GOS on different large bowel regions, three-stage continuous culture systems were conducted in parallel using faecal inocula from three volunteers. Faecal samples were microbially enumerated by quantitative PCR.In vivo, following GOS intervention, bifidobacteria were significantly more compared to post-placebo (P = 0·02). Accordingly, GOS supplementation had a bifidogenic effect in allin vitrosystem vessels. Furthermore, in vessel 1 (similar to the proximal colon), GOS fermentation led to more lactobacilli and increased butyrate. No changes in faecal water genotoxicity were observed. To conclude, GOS supplementation significantly increased bifidobacteria numbersin vivoandin vitro. Increased butyrate production and elevated bifidobacteria numbers may constitute beneficial modulation of the gut microbiota in a maturing population.


2009 ◽  
Vol 103 (3) ◽  
pp. 335-338 ◽  
Author(s):  
Ramadass Balamurugan ◽  
Gemlyn George ◽  
Jayakanthan Kabeerdoss ◽  
Jancy Hepsiba ◽  
Aarthy M. S. Chandragunasekaran ◽  
...  

Gut bacteria contribute to energy conservation in man through their ability to ferment unabsorbed carbohydrate. The present study examined the composition of predominant faecal microbiota in obese and non-obese children. The participants (n 28) aged 11–14 years provided fresh faecal samples and completed a dietary survey consisting of 24 h diet recall and a FFQ of commonly used foods taken over the previous 3 months. Faecal bacteria were quantitated by real-time PCR using primers targeted at 16S rDNA. Of the participants, fifteen (seven female) were obese, with median BMI-for-age at the 99th percentile (range 97 to>99) while thirteen participants (seven female) were normal weight, with median BMI-for age being at the 50th percentile (range 1–85). Consumption of energy, carbohydrates, fat and protein was not significantly different between the obese and non-obese participants. There was no significant difference between the two groups in faecal levels of Bacteroides–Prevotella, Bifidobacterium species, Lactobacillus acidophilus group or Eubacterium rectale. Levels of Faecalibacterium prausnitzii were significantly higher in obese children than in non-obese participants (P = 0·0253). We concluded that the finding of increased numbers of F. prausnitzii in the faeces of obese children in south India adds to the growing information on alterations in faecal microbiota in obesity.


Author(s):  
Tania Aguiar Passeti ◽  
Leandro Ribeiro Bissoli ◽  
Registila Libania Beltrame E Fernando Fonsceca

Background: Methicillin-resistant Staphylococcus aureus (MRSA) causes nosocomial infections, and it has been considered as a worldwide epidemic. The medical system seeks new strategies to fight against MRSA that do not generate resistant strains to antibiotics. Homeopathy has been explored as one of these new strategies, which may play a pivotal role. In this context, we conducted studies on the action of homeopathy on growth of MRSA bacteria in vitro. The results showed a decrease in growth of bacterial strains with homeopathic dilutions of Belladonna and the S. aureus nosode. Now we have proposed to evaluate the minimum inhibitory concentration (MIC) of the antibiotic methicillin or oxacillin on S. aureus MRSA, previously incubated with the homeopathic dilutions of Belladonna or S. aureus nosode. Methods: The Clinical and Laboratory Standards Institute (CLSI 2014) standards were followed according to the determination of the minimum inhibitory concentration (MIC). In 5 mL of cation adjusted Mueller Hinton (CAMH) broth, it was added 420 µl of 30% alcohol or Belladonna and S. aureus’ nosode in the dilutions 6cH, 12cH and 30cH. Then a 20µl of bacterial suspension of MRSA was added to 0.5 McFarland range and diluted to 1/10. The tubes were incubated in an oven at 37⁰C for three hours. The plates were previously prepared with 50µl per well of serial dilutions of the antibiotic oxacillin in concentrations of 128 µg/mL to 0.5 µg/mL in CAMH broth. Then it was added 50 µl per well of bacterial cultures. The plate was incubated in an oven at 37⁰C for 24 hours and the bacterial growth measured in a spectrophotometer 600nm. The point of the MIC of oxacillin for S. aureus is 4 µg/mL, according to CLSI 2014 criteria. Results: We did not observe the total inhibition of bacterial growth when incubated with the homeopathic medicine and oxacillin. In evaluation of the spectrophotometer culture, we observed significant changes in the growth, compared to the control (30% alcohol). Cultures treated with Belladonna 6cH and the antibiotic in the dilution 4 µg/mL showed a decrease of 40% of the growth, while in the 30cH the drop was of 75%. Cultures treated with the S. aureus nosode 30cH and the antibiotic at 4 µg/mL dilution, showed a decrease of 60% in bacterial growth in vitro. Conclusion: The results suggest that bacterial cultures the S. aureus (MRSA) incubated with the homeopathic medicines would be more susceptible to oxacillin’s antimicrobial action.


2008 ◽  
Vol 101 (7) ◽  
pp. 967-971 ◽  
Author(s):  
M. Carmen Marín-Manzano ◽  
Raquel Ruiz ◽  
Elisabeth Jiménez ◽  
Luis A. Rubio ◽  
Alfonso Clemente

Bowman–Birk inhibitor (BBI) from soyabeans is a naturally occurring protease inhibitor with potential anti-inflammatory and chemopreventive properties within the gastrointestinal tract (GIT). In a previous paper, we reported that significant amounts of BBI-related proteins reach the terminal ileum functionally and biologically active. We have now investigated: (a) if soyabean BBI is biotransformed by faecal microbiota which would reduce its potential colorectal chemopreventive properties and (b) the potential influence of this protease inhibitor on the modulation of faecal microbiota. In vitro incubation studies of native soyabean BBI at a physiological level (93 μm) with mixed faecal samples of pigs for 24 h at 37°C demonstrated that BBI remains active and its intrinsic trypsin and chymotrypsin inhibitory activities were not significantly influenced by the enzymic or metabolic activity of faecal microbiota. Soyabean BBI did not affect the growth of the different bacterial groups studied (lactobacilli, bifidobacteria, bacteroides, coliforms, enterobacteria, clostridia and total anaerobes). It was concluded that protease inhibitory activities, intrinsically linked to the chemopreventive properties of soyabean BBI, were largely unaffected by faecal microbiota in vitro. BBI retains significance, therefore, as a bioactive compound in the human GIT.


Molecules ◽  
2019 ◽  
Vol 24 (6) ◽  
pp. 1155 ◽  
Author(s):  
Veronika Jarosova ◽  
Ondrej Vesely ◽  
Petr Marsik ◽  
Jose Jaimes ◽  
Karel Smejkal ◽  
...  

Stilbenoids are dietary phenolics with notable biological effects on humans. Epidemiological, clinical, and nutritional studies from recent years have confirmed the significant biological effects of stilbenoids, such as oxidative stress protection and the prevention of degenerative diseases, including cancer, cardiovascular diseases, and neurodegenerative diseases. Stilbenoids are intensively metabolically transformed by colon microbiota, and their corresponding metabolites might show different or stronger biological activity than their parent molecules. The aim of the present study was to determine the metabolism of six stilbenoids (resveratrol, oxyresveratrol, piceatannol, thunalbene, batatasin III, and pinostilbene), mediated by colon microbiota. Stilbenoids were fermented in an in vitro faecal fermentation system using fresh faeces from five different donors as an inoculum. The samples of metabolized stilbenoids were collected at 0, 2, 4, 8, 24, and 48 h. Significant differences in the microbial transformation among stilbene derivatives were observed by liquid chromatography mass spectrometry (LC/MS). Four stilbenoids (resveratrol, oxyresveratrol, piceatannol and thunalbene) were metabolically transformed by double bond reduction, dihydroxylation, and demethylation, while batatasin III and pinostilbene were stable under conditions simulating the colon environment. Strong inter-individual differences in speed, intensity, and pathways of metabolism were observed among the faecal samples obtained from the donors.


Separations ◽  
2021 ◽  
Vol 8 (9) ◽  
pp. 141
Author(s):  
Khalid Iqbal ◽  
Aliki Milioudi ◽  
Elena Haro Martínez ◽  
Sebastian Georg Wicha

Pharmacokinetic/pharmacodynamic (PKPD) studies of anti-infectives are frequently performed in in vitro infection models where accurate quantification of antibiotic concentrations in bacterial growth media is crucial to establish PK/PD relationships. Here, a sensitive and rapid high-performance liquid chromatography (HPLC) method was developed to quantify tedizolid (TDZ) in the bacterial growth medium Mueller-Hinton broth (MHB). Matrix components were separated by direct protein precipitation with methanol (1:1). The chromatographic separation was carried out in a Dionex Ultimate 3000 HPLC system using an Accucore® C-18 RPMS HPLC column (2.6 µm, 100 × 2.1 mm) using isocratic elution with 25% acetonitrile and 75% of 0.1% formic acid. The lower limit of quantification was 0.03 mg/L when measured at 300 nm. Following relevant European Medicine Agency guidelines, the method was successfully validated for linearity, selectivity, recovery, inter- and intra-day precision, and accuracy and stability. When applied to in vitro PKPD studies, the method successfully quantified a range of TDZ concentration (Cmin, 0.09-Cmax, 0.65 mg/L) in MHB. The analyzed concentrations were in line with the planned PK profiles. The application of the developed method to quantify TDZ in MHB in in vitro PKPD studies is warranted.


2021 ◽  
Vol 9 (3) ◽  
pp. 26
Author(s):  
Yun Xuan Yang ◽  
Vicky Wu ◽  
Hadi Malak ◽  
Aliya Peer Ahamed ◽  
Aaron Lo ◽  
...  

Background and Aim: The aim of this study was to evaluate the effect of varying concentrations of a turmeric solution on the growth rates of oral bacteria sampled from dental students. Methods: Bacterial cultures were grown overnight in aerobic conditions from plaque samples obtained from five test subjects. With the exception of the control, samples were exposed to different treatments; including chlorhexidine gluconate 2 mg/mL, prepared turmeric solution (TS) mouthwash: TS 0.25 mL (7.375 mg/mL), TS 0.5 mL (14.75 mg/mL), and TS 1 mL (29.50 mg/mL). Growth rate of the bacterial cultures were assessed by monitoring changes in optical density readings at 600 nm at hourly intervals for a six-hour period. The data were plotted and the exponential trend was used to calculate individual rates of growth. Data was analyzed using a one-way ANOVA with the significance confirmed using the Tukey-HSD test. Results: Growth observed in the bacteria exposed to the turmeric solution, was significantly greater (p < 0.05) when compared with the bacteria exposed to the medium alone. There was a significant difference found between the bacterial growth rate of the 1 mL turmeric solution against the growth rate of the bacteria in the 0.25 and 0.5 mL turmeric solutions. Conclusion: Comparison of growth rates of oral bacteria suggested that turmeric solutions of concentrations between 7.357 and 29.5 mg/mL (0.25–1 mL) were unlikely to exhibit bacteriostatic or bactericidal properties, and, conversely, increased bacterial growth. Considering this result, it is unlikely that turmeric mouthwash made from store-bought turmeric would have any antibacterial effects against oral bacteria, and may even promote bacterial growth.


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