ABSTRACT
The SARS-CoV-2 is the virus responsible for the COVID-19 pandemic and is plaguing the world since the end of 2019. Different lineages have been discovered ever since and the Gamma lineage, which started the second wave of infections, was first described in Brazil, one of the most affected countries by pandemic. Describing the viral genome and how the virus behaves is essential to contain its propagation and to the development of medications and vaccines. Therefore, this study analyzed SARS-CoV-2 sequenced genomes from Esteio city in Rio Grande do Sul, Southern Brazil. We also comparatively analyzed genomes of the two first years of the pandemic from Rio Grande do Sul state for understanding their genomic and evolutionary patterns. The phylogenomic analysis showed monophyletic groups for Alpha, Gamma, Delta and Omicron, as well as for other circulating lineages in the state. Molecular evolutionary analysis identified several sites under adaptive selection in membrane and nucleocapsid proteins which could be related to a prevalent stabilizing effect on membrane protein structure, as well as majoritarily destabilizing effects on C-terminal nucleocapsid domain.
Subject(s)
COVID-19ABSTRACT
COVID-19 has assumed significant and lasting proportions worldwide. Following initial cases in the Western mesoregion, the State of Santa Catarina (SC), southern Brazil, was heavily affected as a whole by the pandemic in early 2021. This study aimed to evaluate the dynamics of the SARS-CoV-2 virus spreading patterns in the SC state through March 2020 to April 2021 using genomic surveillance. During this period, 23 distinct variants, including two VOCs (Beta and Gamma) were identified, among which, the Gamma and related lineages were predominant in the second pandemic wave within SC. However, a regionalization of P.1-like-II in the Western region was observed, concomitant to the increase in cases, mortality, and case fatality rate (CFR) index. This is the first evidence of the regionalization of the SARS-CoV-2 transmission in the and highlight the importance of tracking variants, dispersion and their impact of SARS-CoV-2 on the public health system in Brazilian states.
Subject(s)
COVID-19ABSTRACT
Background: The massive secretion of inflammatory cytokines is associated with the Coronavirus Disease 2019 (COVID-19) severity and poor prognosis, as well as, in long COVID, the pathophysiology seems to be related to immune deregulation. The patient's immune status can influence the response to Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) virus infection, and this immunity is affected by the intestinal microbiota condition (eubiotic or dysbiotic). This study aimed to evaluate the intestinal microbiota of patients infected with SARS-CoV-2 with different clinical manifestations and post-COVID-19 (post-COV) periods, and correlate with the use of antibiotics during the acute disease. Results: According to the beta diversity, we observed significant differences between microbial communities in stool samples from post-COV patients when compared with healthy controls. Additionally, we detected four different clusters when we grouped patients into asymptomatic, mild, moderate, and severe disease. Patients who took antibiotics during the COVID-19 course showed decreased richness of the gut microbiota, even months after the disease resolution. We detected some genera possibly associated with the persistent post-COV dysbiosis, including increased Prevotella, Dialister, Haemophillus, Barnesiella, Desulfovibrio, Bilophila, Alistipes, Parabacteroides and Bacteroides, suggesting the impact of the disease in the gut microbiota. Besides that, we found some genera associated with antibiotic-induced dysbiosis in post-COV patients, including decreased Akkermansia and Bifidobacterium species. Conclusions: Therefore, we hypothesized that persistent dysbiosis and indiscriminate use of antibiotics during the COVID-19 pandemic may be associated with long COVID syndromes, suggesting the involvement of the gut-lung axis. These data suggest that intestinal microbiota modulation may represent a therapeutic approach for long COVID.
Subject(s)
Dysbiosis , Coronavirus Infections , Reflex, Abnormal , COVID-19ABSTRACT
Coronavirus Disease of 2019 (COVID-19) created dire consequences globally and triggered an enormous scientific effort from different domains. Resulting publications formed a gigantic domain-specific collection of text in which finding studies on a biomolecule of interest is quite challenging for general purpose search engines due to terminology-rich characteristics of the publications. Here, we present Vapur, an online COVID-19 search engine specifically designed for finding related protein - chemical pairs. Vapur is empowered with a biochemically related entities-oriented inverted index in order to group studies relevant to a biomolecule with respect to its related entities. The inverted index of Vapur is automatically created with a BioNLP pipeline and integrated with an online user interface. The online interface is designed for the smooth traversal of the current literature and is publicly available at https://tabilab.cmpe.boun.edu.tr/vapur/.
Subject(s)
COVID-19ABSTRACT
Pool testing has been proposed as an alternative for large-scale SARS-CoV-2 screening. However, dilution factors proportional to the number of pooled samples have been a source of major concern regarding its diagnostic performance. Further, sample pooling can lead to increased laboratory workload and operational complexity. Therefore, pooling strategies that minimize sample dilution, loss of sensitivity, and laboratory overload are needed to allow reliable and large-scale screenings of SARS-CoV-2. Here, we describe a pooling procedure in which nasopharyngeal swabs are pooled together at the time of sample collection (swab pooling), decreasing laboratory manipulation and minimizing dilution of the viral RNA present in the samples. Paired analysis of pooled and individual samples from 613 patients revealed 94 positive individual tests. Having individual testing as a reference, no false-positives or false-negatives were observed for swab pooling. A Bayesian model estimated a sensitivity of 99% (Cr.I. 96.9% to 100%) and a specificity of 99.8% (Cr.I. 99.4% to 100%) for the swab pooling procedure. Data from additional 18,922 patients screened with swab pooling were included for further quantitative analysis. Mean Cq differences between individual and corresponding pool samples ranged from 0.1 Cq (Cr.I. -0.98 to 1.17) to 2.09 Cq (Cr.I. 1.24 to 2.94). Overall, 19,535 asymptomatic and presymptomatic patients were screened using 4,400 RT-qPCR assays, resulting in 246 positive patients (positivity rate 1.26%). This corresponds to an increase of 4.4 times in laboratory capacity and a reduction of 77% in required tests. Finally, these data demonstrate that swab pooling can significantly minimize sample dilution and sensitivity issues commonly seen in its traditional counterpart. Therefore, swab pooling represents a major alternative for reliable and large-scale screening of SARS-CoV-2 in low prevalence populations.
ABSTRACT
We analysed human sewage located in Florianopolis (Santa Catalina, Brazil) from late October until the Brazil lockdown on early March. We detected SARS-CoV-2 in two samples collected independently on 27th November 2019 (5.49{+/-}0.02 log genome copies/L). Subsequent samplings were positive until 4th March 2020 (coinciding with the first COVID-19 case reported in Santa Catalina), with a SARS-CoV-2 RNA increase of one log (6.68{+/-}0.02 log genome copies/L). Our results show that SARS-CoV-2 has been circulating in Brazil since late November 2019, much earlier than the first reported case in the Americas (21st January 2020, USA).