Diagnóstico microbiológico de la infección por SARS-CoV-2 durante la pandemia en Navarra / Microbiological diagnosis of SARS-CoV-2 infection during the pandemic in Navarra

El diagnóstico microbiológico es esencial en el conocimiento y manejo de las enfermedadesinfecciosas, tanto en los procesos habituales de la práctica clínica como en la aparición denuevos microorganismos, como en los próximos que puedan aparecer con el cambio climáticoy la nueva situación de los vectores que transmiten enfermedades en nuestro medio. El 11 de marzo 2020 la Organización Mundial de la Salud declaró la alerta por pandemiamundial por SARS-CoV-2 que se descubrió y se aisló por primera vez en Wuhan, China, en unbrote de neumonía de etiología desconocida vinculada a un mercado. Es una infección quetiene un origen zoonótico, se transmitió de un huésped animal a uno humano. Actualmente nose conoce de forma clara de dónde proviene el SARS-CoV-2. A principios de enero de 2020, científicos chinos anunciaron que habían aislado y secuenciadocompletamente el virus y lo publicaron; esto permitió disponer de técnicas de PCR para realizar eldiagnóstico de la infección por SARS Cov2 en todo el mundo. El objetivo de este trabajo es revisarel papel llevado a cabo desde el Servicio de Microbiología Clínica del Hospital Universitario deNavarra en la pandemia de COVID-19 y, en concreto, en nuestra comunidad, Navarra. Más de dos años después y, sin dejar de lado el profundo impacto sanitario, familiar y socialque ha tenido, debemos quedarnos con lo positivo del aprendizaje profesional y personaladquirido para aplicarlo en nuestro día a día, así como para las futuras pandemias que vengan.(AU)

Estudios de cribado en brotes poblacionales y situaciones especiales / Screening studies in population outbreaks and special situations

La pandemia SARS-CoV-19 se convirtió en un reto global para los sistemas sanitarios mundia-les. Una de las líneas estratégicas para el control de la trasmisión de esta enfermedad fue ladetección precoz de los casos de infección por COVID-19, a través de cribados poblacionales.En la Comunidad Foral de Navarra, a través de un engranaje de varios servicios, se realizaroncribados de detección precoz en diferentes ámbitos: penitenciario, laboral, sociosanitario,escolar, poblaciones con altas incidencias de casos y cualquier otra situación especial queimplicase un riesgo para la Salud Pública. La organización de los cribados en diferentes escenarios fue compleja y requirió una continuaadaptación de recursos materiales y personales.Los continuos cambios, debido a los picos de incidencia de la enfermedad, al aumento de lademanda asistencial y los cambios de protocolos dependiendo de la situación pandémica encada momento, dieron lugar a la incorporación de nuevos profesionales con diferentes perfilesy a la implantación de tareas que no existían. Podemos concluir, tras nuestra experiencia en estos años de pandemia, la importancia demantener un equipo especializado en organización y actuaciones en brotes epidémicos, quefacilitaría una gestión y actuación más eficaz para futuras situaciones, vistas las dificultadesque ha conllevado la escalada de medidas de control de los brotes epidémicos.(AU)

Staphylococcus aureus bacteremia in patients with SARS-CoV-2 infection / Bacteriemia por Staphylococcus aureus en pacientes con infección por SARS-CoV-2

Objectives The aim was to compare the incidence of Staphylococcus aureus bacteremia in COVID-19 and non-COVID-19 adult patients during the pandemic period versus the previous two years. Also, we described the characteristics of both cohorts of patients in pandemic period to find differences. Material and methods Retrospective study in our tertiary-care centre reviewing S. aureus bacteremia episodes in COVID-19 and non-COVID-19 patients through clinical records and the Microbiology Department database. Results In 2018 and 2019, the incidence of S. aureus bacteremia episodes was 1.95 and 1.63 per 1000 admissions respectively. In the pandemic period, global incidence was 1.96 episodes per 1000 non-COVID-19 admissions and 10.59 episodes per 1000 COVID-19 admissions. A total of 241 bacteremia was registered during this pandemic period in 74 COVID-19 patients and in 167 non-COVID-19 patients. Methicillin resistance was detected in 32.4% and 13.8% of isolates from COVID-19 and non-COVID-19 patients respectively. In COVID-19 patients, mortality rates were significantly higher. Conclusions We showed a significantly high rates of S. aureus bacteremia incidence in COVID-19 patients and higher methicillin resistance and 15-day mortality rates than in non-COVID-19 patients (AU)

Objetivos Comparar la incidencia de bacteriemias por Staphylococcus aureus en pacientes adultos COVID-19 y no-COVID-19 durante la pandemia frente a los 2 años previos. Además, describimos las características de ambas cohortes en periodo pandémico para encontrar diferencias. Material y métodos Estudio retrospectivo en nuestro centro de tercer nivel a través de historias clínicas y la base de datos del Servicio de Microbiología Resultados En 2018 y 2019, la incidencia de bacteriemias fue de 1.95 y 1,63 casos por cada 1.000 ingresos respectivamente. En pandemia, la incidencia global fue de 1,96 casos por cada 1.000 ingresos no-COVID-19 y de 10,59 casos por cada 1.000 ingresos COVID-19. Durante la pandemia se registraron 241 bacteriemias en 74 pacientes COVID-19 y en 167 pacientes no-COVID-19. La resistencia a meticilina se detectó en el 32,4 y 13,8% de los aislados de pacientes COVID-19 y no-COVID-19 respectivamente. En pacientes COVID-19 la mortalidad fue significativamente mayor. Conclusiones Mostramos una incidencia significativamente alta de bacteriemias por S. aureus en pacientes COVID-19, así como mayores tasas de resistencia a meticilina y mortalidad a los 15 días que en pacientes no-COVID-19 (AU)

COVID-19 en Pediatría: descripción clínica y microbiológica de los pacientes ingresados en un hospital terciario / COVID-19 in pediatrics: clinical and microbiological description of patients admitted to a tertiary hospital

Introducción: desde el inicio de la pandemia por el virus SARS-CoV-2 una de las grandes cuestiones que se ha formulado es qué papel desempeñan los niños en el control y manejo de la pandemia y cómo esta les ha afectado. Hay mucha bibliografía acerca de los síntomas y complicaciones que puede presentar esta población, pero poca de cómo ha sido el curso clínico de la infección en los niños ingresados en hospitales de tercer nivel y su impacto asistencial. Material y métodos: se han analizado descriptivamente las historias clínicas de los niños ingresados en el Hospital General Doctor Balmis de Alicante (España) desde enero de 2020 hasta julio de 2022. Se han analizado paralelamente los datos microbiológicos del SARS-CoV-2, variantes y linajes, desde agosto de 2021 hasta agosto de 2022. Resultados: se analizaron un total de 114 niños ingresados con diagnóstico de infección por SARS-CoV-2, de los cuales la mayoría tenían menos de 12 meses y eran de procedencia española. Los ingresos se distribuyeron de forma cronológica siguiendo un modelo de “olas”, siendo el motivo más frecuente la constatación del virus SARS-CoV-2 en las pruebas realizadas. El tratamiento que más frecuentemente recibieron durante el ingreso fueron los antibióticos orales. La mayor parte de los niños no tenían comorbilidades y no desarrollaron complicaciones. La variante mayoritaria fue ómicron y el linaje el BA.1. Discusión: los lactantes parecen ser más vulnerables a la infección por SARS-CoV-2 y las manifestaciones clínicas en este grupo de edad conllevan mayor probabilidad de ingreso. El desarrollo de complicaciones, necesidad de oxigenoterapia, ventilación mecánica e ingreso en UCI es mínimo en población pediátrica. El manejo de la infección difiere sustancialmente con el de los adultos, lo que se corresponde con tratamientos menos agresivos (AU)

Introduction: since the beginning of the SARS-CoV-2 pandemic, one of the main questions that has been asked is what role children play in the control and management of the pandemic and how it has affected them. There is much literature on the symptoms and complications that this population may have, but little on the clinical course of the infection in children admitted to tertiary hospitals and its impact on health care.Material and methods: the clinical histories of children admitted to the Hospital General Doctor Balmis (Alicante, Spain) from January 2020 to July 2022 were analyzed descriptively. At the same time, microbiological data on SARS-CoV-2, variants and lineages were analyzed from August 2021 to August 2022.Results: a total of 114 children admitted were analyzed, most of whom were younger than 12 months and from Spain. Admissions were distributed chronologically following a 'wave' pattern, the most frequent reason being the finding of SARS-CoV-2 virus in the tests performed. The most common treatment received during admission was oral antibiotics. Most of the children had no comorbidities and did not develop complications.Discussion: infants seem to be more vulnerable to SARS-CoV-2 infection, and clinical manifestations in this age group are more likely to lead to admission. The development of complications, need for oxygen therapy, mechanical ventilation and admission to the ICU is minimal in the pediatric population. The management of infection differs substantially from that of adults, which corresponds to less aggressive treatment. (AU)

Pathogenicity, infective dose and altered gut microbiota in piglets infected with porcine deltacoronavirus.

Porcine deltacoronavirus (PDCoV) is an emerging swine enteropathogenic coronavirus that cause severe diarrhea, resulting in high mortality in neonatal piglets. Little is known regarding the pathogenicity of PDCoV in different infective dose and the dynamic changes in the composition of the gut microbiota in PDCoV-induced diarrhea piglets. In this study, 5-day-old piglets were experimentally infected with different dose of PDCoV. The challenged piglets developed typical symptoms, characterized by acute and severe watery diarrhea from 1 to 8 days post-inoculation (DPI), and viral shedding was detected in rectal swab until 11 DPI. Tissues of small intestines displayed significant macroscopic and microscopic lesions with clear viral antigen expression. However, no significant differences among groups were found in challenged piglets. Then alteration in gut microbiota in the jejunum and colon of PDCoV infected-piglets were analyzed using 16S rRNA sequencing. PDCoV infection reduced bacterial diversity and richness, and significantly altered the structure and abundance of the microbiota from the phylum to genus. Fusobacterium, and Proteobacteria was significantly increased (P < 0.05), while the abundance of Bacteroidota was markedly decreased in the infected-piglets. Furthermore, microbial function prediction indicated that the changes in intestinal bacterial also affected the immune system, excretory system, circulatory system, neurodegenerative disease, cardiovascular disease, xenobiotics biodegradation and metabolism, etc. These findings suggest that regulating gut microbiota community may be an effective approach for preventing PDCoV infection.

Immune Responses and B Complex Associated Resistance to Infectious Bronchitis Virus in Chickens.

Infectious bronchitis (IB) continues to be a global threat to poultry producers. The chicken major histocompatibility complex (MHC) or chicken B complex is compact, restricted to a single chromosome, and approximately 20-fold smaller than the mammalian MHC. Abundant evidence indicates that the B complex is strongly associated with resistance to various infectious agents in chickens. While an association between different B haplotypes and resistance against several bacterial and viral diseases has been established, additional work needs to be performed on the association between the B complex and resistance to IB viruses (IBV). Here, some of the available knowledge on genetic resistance to viral poultry diseases conferred by the chicken B locus is reviewed. IBV immune responses and resistance associated with differing B haplotype chicken lines are reviewed and discussed herein.

Estudio recapitulativo- Respuestas inmunitarias y resistencia asociada al complejo B contra el virus de la bronquitis infecciosa en pollos. La bronquitis infecciosa sigue siendo una amenaza mundial para los productores avícolas. El complejo mayor de histocompatibilidad (MHC) o complejo B del pollo es compacto, restringido a un solo cromosoma y aproximadamente 20 veces más pequeño que el complejo mayor de histocompatibilidad de mamíferos. Existe abundante evidencia que indica que el complejo B está fuertemente asociado con la resistencia a varios agentes infecciosos en pollos. Si bien se ha establecido una asociación entre diferentes haplotipos B y la resistencia contra varias enfermedades bacterianas y virales, es necesario realizar un trabajo adicional sobre la asociación entre el complejo B y la resistencia a los virus de bronquitis infecciosa. A continuación, se revisan algunos de los conocimientos disponibles sobre la resistencia genética a las enfermedades virales en avicultura conferidos por el locus B del pollo. Las respuestas inmunes contra el virus de la bronquitis infecciosa y la resistencia asociadas con diferentes líneas de pollo de diferentes haplotipos B se revisan y se discuten en este artículo.

Severity of Respiratory Infections With Seasonal Coronavirus Is Associated With Viral and Bacterial Coinfections.

The clinical presentation of human coronavirus (HCoV) infections in children varies strongly. We show that children with an HCoV-associated lower respiratory tract infection more frequently had respiratory syncytial virus codetected and higher abundance of Haemophilus influenzae/haemolyticus than asymptomatic HCoV carriers as well as children with a non-HCoV-associated lower respiratory tract infection. Viral and bacterial cooccurrence may drive symptomatology of HCoV-associated infections including coronavirus disease 2019.

A propósito del nuevo coronavirus: microbioturismo / About the new coronavirus: Microbiotourism

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COVID-19: Is there a role for immunonutrition in obese patient?

On December 12, 2019 a new coronavirus (SARS-CoV-2) emerged in Wuhan, China, triggering a pandemic of severe acute respiratory syndrome in humans (COVID-19). Today, the scientific community is investing all the resources available to find any therapy and prevention strategies to defeat COVID-19. In this context, immunonutrition can play a pivotal role in improving immune responses against viral infections. Immunonutrition has been based on the concept that malnutrition impairs immune function. Therefore, immunonutrition involves feeding enriched with various pharmaconutrients (Omega 3 Fatty Acids, Vitamin C, Arginine, Glutamine, Selenium, Zinc, Vitamin, E and Vitamin D) to modulate inflammatory responses, acquired immune response and to improve patient outcomes. In literature, significant evidences indicate that obesity, a malnutrition state, negatively impacts on immune system functionality and on host defense, impairing protection from infections. Immunonutrients can promote patient recovery by inhibiting inflammatory responses and regulating immune function. Immune system dysfunction is considered to increase the risk of viral infections, such as SARS-CoV-2, and was observed in different pathological situations. Obese patients develop severe COVID-19 sequelae, due to the high concentrations of TNF-α, MCP-1 and IL-6 produced in the meantime by visceral and subcutaneous adipose tissue and by innate immunity. Moreover, leptin, released by adipose tissue, helps to increase inflammatory milieu with a dysregulation of the immune response. Additionally, gut microbiota plays a crucial role in the maturation, development and functions of both innate and adaptive immune system, as well as contributing to develop obese phenotype. The gut microbiota has been shown to affect lung health through a vital crosstalk between gut microbiota and lungs, called the "gut-lung axis". This axis communicates through a bi-directional pathway in which endotoxins, or microbial metabolites, may affect the lung through the blood and when inflammation occurs in the lung, this in turn can affect the gut microbiota. Therefore, the modulation of gut microbiota in obese COVID-19 patients can play a key role in immunonutrition therapeutic strategy. This umbrella review seeks to answer the question of whether a nutritional approach can be used to enhance the immune system's response to obesity in obese patients affected by COVID-19.

COVID-19 - gastrointestinal and gut microbiota-related aspects.

OBJECTIVE: The aim of this review paper was to discuss the gut microbiota-related aspects of COVID-19 patients. We presented the faecal-oral transmission of SARS-CoV-2, gut microbiota imbalance, and fecal microbiota transplantation as a hidden source of this virus. MATERIALS AND METHODS: We analyzed the available literature (PubMed, Embase, Google Scholar databases) regarding COVID-19 and gut microbiota related aspects. RESULTS: The gastrointestinal symptoms, such as nausea, vomiting, diarrhea, abdominal discomfort/pain, may occur in these patients. Notably, these symptoms may contribute to the severity of COVID-19. Recent several studies have revealed a new SARS-CoV-2 transmission possibility, opening a fresh view on COVID-19. It is observed the possibility of SARS-CoV-2 transmission via faecal-oral route. Fecal microbiota transplantation may be a hidden source of SARS-CoV-2. Additionally, the pharmacological treatment of COVID-19 and other factors may significantly alter the composition of gut microbiota. Among others, loss of bacterial diversity, the decrease of commensal microbes as well as the increase of opportunistic pathogens are observed. CONCLUSIONS: The alterations of gut microbiota in COVID-19 patients consequently may lead to the development of gut dysbiosis-related diseases even after recovery from COVID-19. Therefore, it is recommended to screen stool samples taken from recovered patients at least 35 days after clearance of virus from respiratory tract. Before 35 days period, SARS-CoV-2 may still be detected in feces. It is also recommended to screen the composition as well as the activity of gut microbiota to assess its balance. In the case of gut dysbiosis, there should be introduced an appropriate method of its modulation. Additionally, all the fecal samples which are prepared for fecal microbiota transplantation should be tested for SARS-CoV-2 to provide protection for its recipients.

Probiotics in Medicine: A Long Debate.

During the last years probiotics gained the attention of clinicians for their use in the prevention and treatment of multiple diseases. Probiotics main mechanisms of action include enhanced mucosal barrier function, direct antagonism with pathogens, inhibition of bacterial adherence and invasion capacity in the intestinal epithelium, boosting of the immune system and regulation of the central nervous system. It is accepted that there is a mutual communication between the gut microbiota and the liver, the so-called "microbiota-gut-liver axis" as well as a reciprocal communication between the intestinal microbiota and the central nervous system through the "microbiota-gut-brain axis." Moreover, recently the "gut-lung axis" in bacterial and viral infections is considerably discussed for bacterial and viral infections, as the intestinal microbiota amplifies the alveolar macrophage activity having a protective role in the host defense against pneumonia. The importance of the normal human intestinal microbiota is recognized in the preservation of health. Disease states such as, infections, autoimmune conditions, allergy and other may occur when the intestinal balance is disturbed. Probiotics seem to be a promising approach to prevent and even reduce the symptoms of such clinical states as an adjuvant therapy by preserving the balance of the normal intestinal microbiota and improving the immune system. The present review states globally all different disorders in which probiotics can be given. To date, Stronger data in favor of their clinical use are provided in the prevention of gastrointestinal disorders, antibiotic-associated diarrhea, allergy and respiratory infections. We hereby discuss the role of probiotics in the reduction of the respiratory infection symptoms and we focus on the possibility to use them as an adjuvant to the therapeutic approach of the pandemic COVID-19. Nevertheless, it is accepted by the scientific community that more clinical studies should be undertaken in large samples of diseased populations so that the assessment of their therapeutic potential provide us with strong evidence for their efficacy and safety in clinical use.

Impact of Microbiota: A Paradigm for Evolving Herd Immunity against Viral Diseases.

Herd immunity is the most critical and essential prophylactic intervention that delivers protection against infectious diseases at both the individual and community level. This process of natural vaccination is immensely pertinent to the current context of a pandemic caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection around the globe. The conventional idea of herd immunity is based on efficient transmission of pathogens and developing natural immunity within a population. This is entirely encouraging while fighting against any disease in pandemic circumstances. A spatial community is occupied by people having variable resistance capacity against a pathogen. Protection efficacy against once very common diseases like smallpox, poliovirus or measles has been possible only because of either natural vaccination through contagious infections or expanded immunization programs among communities. This has led to achieving herd immunity in some cohorts. The microbiome plays an essential role in developing the body's immune cells for the emerging competent vaccination process, ensuring herd immunity. Frequency of interaction among microbiota, metabolic nutrients and individual immunity preserve the degree of vaccine effectiveness against several pathogens. Microbiome symbiosis regulates pathogen transmissibility and the success of vaccination among different age groups. Imbalance of nutrients perturbs microbiota and abrogates immunity. Thus, a particular population can become vulnerable to the infection. Intestinal dysbiosis leads to environmental enteropathy (EE). As a consequence, the generation of herd immunity can either be delayed or not start in a particular cohort. Moreover, disparities of the protective response of many vaccines in developing countries outside of developed countries are due to inconsistencies of healthy microbiota among the individuals. We suggested that pan-India poliovirus vaccination program, capable of inducing herd immunity among communities for the last 30 years, may also influence the inception of natural course of heterologous immunity against SARS-CoV-2 infection. Nonetheless, this anamnestic recall is somewhat counterintuitive, as antibody generation against original antigens of SARS-CoV-2 will be subdued due to original antigenic sin.

Post lockdown COVID-19 seroprevalence and circulation at the time of delivery, France.

BACKGROUND: To fight the COVID-19 pandemic, lockdown has been decreed in many countries worldwide. The impact of pregnancy as a severity risk factor is still debated, but strict lockdown measures have been recommended for pregnant women. OBJECTIVES: To evaluate the impact of the COVID-19 pandemic and lockdown on the seroprevalence and circulation of SARS-CoV-2 in a maternity ward in an area that has been significantly affected by the virus. STUDY DESIGN: Prospective study at the Antoine Béclère Hospital maternity ward (Paris area, France) from May 4 (one week before the end of lockdown) to May 31, 2020 (three weeks after the end of lockdown). All patients admitted to the delivery room during this period were offered a SARS-CoV-2 serology test as well concomitant SARS-CoV-2 RT-PCR on one nasopharyngeal sample. RESULTS: A total of 249 women were included. Seroprevalence of SARS-CoV-2 was 8%. The RT-PCR positive rate was 0.5%. 47.4% of the SARS-CoV-2-IgG-positive pregnant women never experienced any symptoms. A history of symptoms during the epidemic, such as fever (15.8%), myalgia (36.8%) and anosmia (31.6%), was suggestive of previous infection. CONCLUSIONS: Three weeks after the end of French lockdown, SARS-CoV-2 infections were scarce in our region. A very high proportion of SARS-CoV-2-IgG-negative pregnant women, which is comparable to that of the general population, must be taken into consideration in the event of a resurgence of the pandemic. The traces of a past active circulation of the virus in this fragile population during the spring wave should encourage public health authorities to take specific measures for this independent at-risk group, in order to reduce viral circulation in pregnant patients.

Probiotics in Treatment of Viral Respiratory Infections and Neuroinflammatory Disorders.

Inflammation is a biological response to the activation of the immune system by various infectious or non-infectious agents, which may lead to tissue damage and various diseases. Gut commensal bacteria maintain a symbiotic relationship with the host and display a critical function in the homeostasis of the host immune system. Disturbance to the gut microbiota leads to immune dysfunction both locally and at distant sites, which causes inflammatory conditions not only in the intestine but also in the other organs such as lungs and brain, and may induce a disease state. Probiotics are well known to reinforce immunity and counteract inflammation by restoring symbiosis within the gut microbiota. As a result, probiotics protect against various diseases, including respiratory infections and neuroinflammatory disorders. A growing body of research supports the beneficial role of probiotics in lung and mental health through modulating the gut-lung and gut-brain axes. In the current paper, we discuss the potential role of probiotics in the treatment of viral respiratory infections, including the COVID-19 disease, as major public health crisis in 2020, and influenza virus infection, as well as treatment of neurological disorders like multiple sclerosis and other mental illnesses.

SARS-CoV-2-related pneumonia cases in pneumonia picture in Russia in March-May 2020: Secondary bacterial pneumonia and viral co-infections.

BACKGROUND: We are communicating the results of investigating statistics on SARS-CoV-2-related pneumonias in Russia: percentage, mortality, cases with other viral agents, cases accompanied by secondary bacterial pneumonias, age breakdown, clinical course and outcome. METHODS: We studied two sampling sets (Set 1 and Set 2). Set 1 consisted of results of testing 3382 assays of out-patients and hospital patients (5-88 years old) with community-acquired and hospital-acquired pneumonia of yet undetermined aetiology. Set 2 contained results of 1204 assays of hospital patients (12-94 years old) with pneumonia and COVID-19 already diagnosed by molecular biological techniques in test laboratories. The results were collected in twelve Russian cities/provinces in time range 2 March - 5 May 2020. Assays were analysed for 10 bacterial, 15 viral, 2 fungal and 2 parasitic aetiological agents. RESULTS: In Set 1, 4.35% of total pneumonia cases were related to SARS-CoV-2, with substantially larger proportion (18.75%) of deaths of pneumonia with COVID-19 diagnosed. However, studying Set 2, we revealed that 52.82% patients in it were also positive for different typical and atypical aetiological agents usually causing pneumonia. 433 COVID-19 patients (35.96%) were tested positive for various bacterial aetiological agents, with Streptococcus pneumoniae, Staphylococcus aureus and Haemophilus influenzae infections accounting for the majority of secondary pneumonia cases. CONCLUSIONS: SARS-CoV-2, a low-pathogenic virus itself, becomes exceptionally dangerous if secondary bacterial pneumonia attacks a COVID-19 patient as a complication. An essential part of the severest complications and mortality associated with COVID-19 in Russia in March-May 2020, may be attributed to secondary bacterial pneumonia and to a much less extent viral co-infections. The problem of hospital-acquired bacterial infection is exceptionally urgent in treating SARS-CoV-2 patients. The risk of secondary bacterial pneumonia and its further complications, should be given very serious attention in combating SARS-CoV-2.

The probiotic Bifidobacterium in the management of Coronavirus: A theoretical basis.

COVID-19 is a viral pandemic that primarily manifests with respiratory distress but may also lead to symptoms and signs associated with the gastrointestinal tract. It is characteristically associated with a hyper-immune response, also referred to as a 'cytokine storm'. Probiotics are living microorganisms that have been shown to have positive effects on immune response in man with some bacteria; some strains of Bifidobacteria, for example, possess especially potent immune modulating effects. These bacteria have the potential to ameliorate the 'cytokine storm' through a differential effect on pro- and anti-inflammatory cytokines. In the management of COVID-19 and other coronovirus-mediated illnesses, probiotic bacteria also have the potential to enhance vaccine efficacy.

Probiotics for treating novel coronavirus with diarrhea: A protocol for systematic review and meta analysis.

BACKGROUND: The study aims to evaluate the efficacy and safety of probiotic therapy for coronavirus disease 2019 with diarrhea. METHODS: The following electronic bibliographic databases will be searched to identify relevant studies from December 2019 to December 2020: MEDLINE, PubMed, Embase, the Cochrane Central Register of Controlled Trials, China National Knowledge Infrastructure, Chinese Technical Periodicals, Wan-fang data, Chinese Biological Medicine Database, and other databases. The search results will not be restricted by language, all included articles were randomized controlled trial. Two independent researchers will conduct article retrieval, de-duplication, filtering, quality assessment, and data analysis through the Review Manager (V.5.3). Meta-analysis, subgroup analysis and/or descriptive analysis were performed on the included data. RESULTS: High-quality synthesis and/or descriptive analysis of current evidence will be provided from outcomes. CONCLUSION: This study will provide the evidence of whether probiotics is an effective and safe intervention for coronavirus disease 2019 with diarrhea.PROSPERO registration number: CRD42020192657.

Engineering of a Dual-Recognition Ratiometric Fluorescent Nanosensor with a Remarkably Large Stokes Shift for Accurate Tracking of Pathogenic Bacteria at the Single-Cell Level.

Rapid, accurate, reliable, and risk-free tracking of pathogenic microorganisms at the single-cell level is critical to achieve efficient source control and prevent outbreaks of microbial infectious diseases. For the first time, we report a promising approach for integrating the concepts of a remarkably large Stokes shift and dual-recognition into a single matrix to develop a pathogenic microorganism stimuli-responsive ratiometric fluorescent nanoprobe with speed, cost efficiency, stability, ultrahigh specificity, and sensitivity. As a proof-of-concept, we selected the Gram-positive bacterium Staphylococcus aureus (S. aureus) as the target analyte model, which easily bound to its recognition aptamer and the broad-spectrum glycopeptide antibiotic vancomycin (Van). To improve the specificity and short sample-to-answer time, we employed classic noncovalent π-π stacking interactions as a driving force to trigger the binding of Van and aptamer dual-functionalized near-infrared (NIR) fluorescent Apt-Van-QDs to the surface of an unreported blue fluorescent π-rich electronic carbon nanoparticles (CNPs), achieving S. aureus stimuli-responsive ratiometric nanoprobe Apt-Van-QDs@CNPs. In the assembly of Apt-Van-QDs@CNPs, the blue CNPs (energy donor) and NIR Apt-Van-QDs (energy acceptor) became close to allow the fluorescence resonance energy transfer (FRET) process, leading to a remarkable blue fluorescence quenching for the CNPs at ∼465 nm and a clear NIR fluorescence enhancement for Apt-Van-QDs at ∼725 nm. In the presence of S. aureus, the FRET process from CNPs to Apt-Van-QDs was disrupted, causing the nanoprobe Apt-Van-QDs@CNPs to display a ratiometric fluorescent response to S. aureus, which exhibited a large Stokes shift of ∼260 nm and rapid sample-to-answer detection time (∼30.0 min). As expected, the nanoprobe Apt-Van-QDs@CNPs showed an ultrahigh specificity for ratiometric fluorescence detection of S. aureus with a good detection limit of 1.0 CFU/mL, allowing the assay at single-cell level. Moreover, we also carried out the precise analysis of S. aureus in actual samples with acceptable results. We believe that this work offers new insight into the rational design of efficient ratiometric nanoprobes for rapid on-site accurate screening of pathogenic microorganisms at the single-cell level in the early stages, especially during the worldwide spread of COVID-19 today.

Obesity and diabetes as comorbidities for COVID-19: Underlying mechanisms and the role of viral-bacterial interactions.

Obesity and diabetes are established comorbidities for COVID-19. Adipose tissue demonstrates high expression of ACE2 which SARS- CoV-2 exploits to enter host cells. This makes adipose tissue a reservoir for SARS-CoV-2 viruses and thus increases the integral viral load. Acute viral infection results in ACE2 downregulation. This relative deficiency can lead to disturbances in other systems controlled by ACE2, including the renin-angiotensin system. This will be further increased in the case of pre-conditions with already compromised functioning of these systems, such as in patients with obesity and diabetes. Here, we propose that interactions of virally-induced ACE2 deficiency with obesity and/or diabetes leads to a synergistic further impairment of endothelial and gut barrier function. The appearance of bacteria and/or their products in the lungs of obese and diabetic patients promotes interactions between viral and bacterial pathogens, resulting in a more severe lung injury in COVID-19.