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1.
Microbiome ; 9(1): 180, 2021 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-34470652

RESUMO

BACKGROUND: Probiotics have been used to regulate the gut microbiota and physiology in various contexts, but their precise mechanisms of action remain unclear. RESULTS: By population genomic analysis of 418 Bifidobacterium longum strains, including 143 newly sequenced in this study, three geographically distinct gene pools/populations, BLAsia1, BLAsia2, and BLothers, were identified. Genes involved in cell wall biosynthesis, particularly peptidoglycan biosynthesis, varied considerably among the core genomes of the different populations, but accessory genes that contributed to the carbohydrate metabolism were significantly distinct. Although active transmission was observed inter-host, inter-country, inter-city, intra-community, and intra-family, a single B. longum clone seemed to reside within each individual. A significant negative association was observed between host age and relative abundance of B. longum, while there was a strong positive association between host age and strain genotype [e.g., single nucleotide polymorphisms in the arginine biosynthesis pathway]. Further animal experiments performed with the B. longum isolates via using a D-galactose-induced aging mouse model supported these associations, in which B. longum strains with different genotypes in arginine biosynthesis pathway showed divergent abilities on protecting against host aging possibly via their different abilities to modify the metabolism of gut microbes. CONCLUSIONS: This is the first known example of research on the evolutionary history and transmission of this probiotic species. Our results propose a new mechanistic insight for promoting host longevity via the informed use of specific probiotics or molecules. Video abstract.


Assuntos
Bifidobacterium longum , Microbioma Gastrointestinal , Probióticos , Sulfaleno , Envelhecimento , Animais , Galactose , Microbioma Gastrointestinal/genética , Humanos , Camundongos
2.
Proc Natl Acad Sci U S A ; 118(36)2021 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-34465619

RESUMO

The second plague pandemic started in Europe with the Black Death in 1346 and lasted until the 19th century. Based on ancient DNA studies, there is a scientific disagreement over whether the bacterium, Yersinia pestis, came into Europe once (Hypothesis 1) or repeatedly over the following four centuries (Hypothesis 2). Here, we synthesize the most updated phylogeny together with historical, archeological, evolutionary, and ecological information. On the basis of this holistic view, we conclude that Hypothesis 2 is the most plausible. We also suggest that Y. pestis lineages might have developed attenuated virulence during transmission, which can explain the convergent evolutionary signals, including pla decay, that appeared at the end of the pandemics.

3.
Front Public Health ; 9: 694705, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34409008

RESUMO

The COVID-19 pandemic, caused by the novel coronavirus SARS-CoV-2, has been characterized by unprecedented rates of spatio-temporal spread. Here, we summarize the main events in the pandemic's timeline and evaluate what has been learnt by the public health community. We also discuss the implications for future public health policy and, specifically, the practice of epidemic control. We critically analyze this ongoing pandemic's timeline and contrast it with the 2002-2003 SARS outbreak. We identify specific areas (e.g., pathogen identification and initial reporting) wherein the international community learnt valuable lessons from the SARS outbreak. However, we also identify the key areas where international public health policy failed leading to the exponential spread of the pandemic. We outline a clear agenda for improved pandemic control in the future.


Assuntos
COVID-19 , Pandemias , Surtos de Doenças/prevenção & controle , Humanos , Pandemias/prevenção & controle , Saúde Pública , SARS-CoV-2
4.
J Glob Antimicrob Resist ; 26: 194-198, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34146740

RESUMO

OBJECTIVES: The aims of this study were to infer the phylogenetic relationship of OXA-232-producing Klebsiella pneumoniae (OXA232Kp) strains collected from a Chinese hospital and to determine the composition and genetic background of antimicrobial resistance genes (ARGs) among these strains. METHODS: Three non-duplicate OXA232Kp strains were collected from a Chinese hospital. Whole-genome sequencing was used to determine their genome sequences and then a genomic comparison of ARG-carrying genetic elements from the three strains with related sequences was performed. Phylogenetic analysis was conducted by constructing a maximum-likelihood phylogenetic tree. RESULTS: Compared with other Chinese sequence type 15 (ST15)-OXA232Kp strains, the three ST15-OXA232Kp strains in this study could be divided into a single subgroup in phylogenetic relationship. The composition and genetic background of ARGs were identical in the three strains. Three ARG-carrying genetic elements or multidrug resistance (MDR) regions were determined, including a truncated Tn2013-like IS-based transposition unit, a unit transposition Tn6867b and a 40.9-kb MDR region. CONCLUSION: This study reported clonal dissemination of ST15-OXA232Kp strains carrying multiple ARGs in a Chinese hospital. A comprehensive evolutionary and genomics analysis provided a deeper understanding of OXA232Kp. Further surveillance and study should be advocated to prevent the dissemination of OXA232Kp strains in China.

5.
Gut Microbes ; 13(1): 1-15, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34006193

RESUMO

The gut microbiota in the hepatitis B virus related acute-on-chronic liver failure (HBV-ACLF) is poorly defined. We aim to uncover the characteristics of the gut microbiota in HBV-ACLF and in other HBV associated pathologies. We analyzed the gut microbiome in patients with HBV-ACLF or other HBV associated pathologies and healthy individuals by 16S rRNA sequencing and metagenomic sequencing of fecal samples. 212 patients with HBV-ACLF, 252 with chronic hepatitis B (CHB), 162 with HBV-associated cirrhosis (HBV-LC) and 877 healthy individuals were recruited for the study. CHB and HBV-LC patients are grouped as HBV-Other. We discovered striking differences in the microbiome diversity between the HBV-ACLF, HBV-Other and healthy groups using 16S rRNA sequencing. The ratio of cocci to bacilli was significantly elevated in the HBV-ACLF group compared with healthy group. Further analysis within the HBV-ACLF group identified 52 genera showing distinct richness within the group where Enterococcus was enriched in the progression group whilst Faecalibacterium was enriched in the regression group. Metagenomic sequencing validated these findings and further uncovered an enrichment of Lactobacillus casei paracasei in progression group, while Alistipes senegalensis, Faecalibacterium prausnitzii and Parabacteroides merdae dominated the regression group. Importantly, our analysis revealed that there was a rapid increase of Enterococcus faecium during the progression of HBV-ACLF. The gut microbiota displayed distinct composition at different phases of HBV-ACLF. High abundance of Enterococcus is associated with progression while that of Faecalibacterium is associated with regression of HBV-ACLF. Therefore, the microbiota features hold promising potential as prognostic markers for HBV-ACLF.

6.
Mol Cell Proteomics ; 20: 100066, 2021 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-33631294

RESUMO

Plague is a zoonotic disease that primarily infects rodents via fleabite. Transmission from flea to host niches requires rapid adaption of Yersinia pestis to the outer environments to establish infection. Here, quantitative proteome and secretome analyses of Y. pestis grown under conditions mimicking the two typical niches, i.e., the mammalian host (Mh) and the flea vector (Fv), were performed to understand the adaption strategies of this deadly pathogen. A secretome of Y. pestis containing 308 proteins has been identified using TMT-labeling mass spectrometry analysis. Although some proteins are known to be secreted, such as the type III secretion substrates, PsaA and F1 antigen, most of them were found to be secretory proteins for the first time. Comparative proteomic analysis showed that membrane proteins, chaperonins and stress response proteins are significantly upregulated under the Mh condition, among which the previously uncharacterized proteins YP_3416∼YP_3418 are remarkable because they cannot only be secreted but also translocated into HeLa cells by Y. pestis. We further demonstrated that the purified YP_3416 and YP_3418 exhibited E3 ubiquitin ligase activity in in vitro ubiquitination assay and yp_3416∼3418 deletion mutant of Y. pestis showed significant virulence attenuation in mice. Taken together, our results represent the first Y. pestis secretome, which will promote the better understanding of Y. pestis pathogenesis, as well as the development of new strategies for treatment and prevention of plague.

7.
Biosens Bioelectron ; 179: 113057, 2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-33578111

RESUMO

The rapid and early detection of foodborne pathogens in contaminated food is important for ensuring food safety and quality. In this study, a highly sensitive fluorescent immunosensor was developed to detect Escherichia coli O157:H7 in milk, by using microspheres labeled with carbon dots (CDs). The CDs-microspheres were prepared with Staphylococcus aureus cells as the carrier to incorporate CDs particles. Characterization of the microsphere revealed strong intensity, good stability and high uniformity in fluorescence. With Staphylococcal Protein A (SPA) on the surface of S. aureus cells, the microsphere could be easily coupled with various antibodies (e.g., immunoglobulin G). In combination with the immunomagnetic beads technique, a CDs-microsphere immunosensor was established for the specific detection of E. coli O157:H7 in milk. The limit of detection for E. coli O157:H7 is 2.4 × 102 colony-forming unit (CFU)/mL, comparable to that of real-time PCR methods. Milk samples spiked with E. coli O157:H7 at concentrations from 2.4 × 102 to 2.4 × 107 CFU/mL could be detected within 30 min. The coefficients of variation of the intra-assay tests were less than 10%, indicating a good repeatability. Moreover, the method was able to detect trace amounts of E. coli O157:H7 (<10 CFU) in real milk samples, with a 100% (10/10) accuracy after bacterial enrichment. This CDs-microsphere immunosensor shows considerable potential as a rapid and sensitive tool to detect pathogens in milk and other foods.


Assuntos
Técnicas Biossensoriais , Escherichia coli O157 , Animais , Carbono , Microbiologia de Alimentos , Imunoensaio , Microesferas , Leite , Staphylococcus aureus
8.
J Cell Physiol ; 236(8): 5495-5511, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-33452716

RESUMO

Programmed cell death protein-1/programmed cell death-ligand 1 and cytotoxic T-lymphocyte antigen-4 are two immune checkpoint inhibitors (ICIs), exhibiting significant antitumor effects on multiple types of cancers in clinical practice. However, only some patients respond to ICI agents, which limits their widespread application. Recent findings revealed that the gut microbiota is relevant to host health through the modulation of host physical and immune functions. Therefore, the modulation of gut microbiota to achieve the desired taxa may be a potential strategy to improve the efficacy of immunotherapies. In this review, we classified the relative microbes according to their taxonomic information and aimed to clarify their modulatory functions and potent effects on ICI immunotherapy by focusing on recent trials investigating the relationships between the gut microbiota and ICIs.

9.
Life Sci ; 264: 118450, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33131749

RESUMO

AIMS: Hydroxychloroquine (HCQ), a widely used antimalarial drug, is proposed to treat coronavirus disease 2019 (COVID-19). However, no report is currently available regarding the direct effects of HCQ on gut microbiota, which is associated with the outcomes of elderly patients with COVID-19. Here, we first investigated the effects of HCQ on intestinal microecology in mice. MAIN METHODS: Fifteen female C57BL/6J mice were randomly divided into two groups: HCQ group (n = 10) and control group (n = 5). Mice in the HCQ group were administered with HCQ at dose of 100 mg/kg by gavage daily for 14 days. The feces of mice were collected before and on the 7th and 14th days after HCQ challenge, and then analyzed by 16S rRNA amplicon sequencing. At the end of the experiment, the hematology, serum biochemistry and cytokines were determined, respectively. The mRNA expression of tight junction proteins in colonic tissues were also studied by RT-PCR. KEY FINDINGS: HCQ challenge had no effects on the counts of white blood cells, the levels of serum cytokines, and the gene expression of tight junction proteins in colon. HCQ also did not increase the content of serum d-lactate in mice. Notably, HCQ significantly decreased the diversity of gut microbiota, increased the relative abundance of phylum Bacteroidetes whereas decreased that of Firmicutes. SIGNIFICANCE: Short-term high dose HCQ challenge changes gut microbiota but not the intestinal integrity and immunological responses in mice. Special attention should be paid to the effects of HCQ on intestinal microecology in future clinical use.


Assuntos
Colo/efeitos dos fármacos , Colo/imunologia , Microbioma Gastrointestinal/efeitos dos fármacos , Microbioma Gastrointestinal/imunologia , Hidroxicloroquina/administração & dosagem , Hidroxicloroquina/efeitos adversos , Administração Oral , Animais , Colo/metabolismo , Citocinas/sangue , Citocinas/imunologia , Fezes/microbiologia , Feminino , Ácido Láctico/sangue , Camundongos , RNA Ribossômico 16S/genética , Proteínas de Junções Íntimas/biossíntese
10.
Eur J Clin Microbiol Infect Dis ; 40(5): 921-928, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33184753

RESUMO

Serological test is a valuable diagnostic tool for coronavirus disease 2019 (COVID-19). However, considerable improvements to these tests are needed, especially in the detection sensitivity. In this study, six recombinant nucleocapsid and spike proteins of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) were prepared and evaluated, including three prokaryotic expression nucleocapsid proteins (rN, rN1, rN2) and three eukaryotic expression spike proteins (rS1, rS-RBD, rS-RBD-mFc). The recombinant proteins with the highest ELISA titers (rS1 and rS-RBD-mFc) were selected to develop a double-antigen sandwich colloidal gold immunochromatography assay (GICA) to detect total antibodies against SARS-CoV-2. The clinical evaluation results showed that the sensitivity and specificity of GICA were 92.09% (419/455) and 99.44% (706/710), respectively. Moreover, a significant number (65.63%, 21/32) of COVID-19 patients with undetectable viral RNA were correctly diagnosed by the GICA method. In conclusion, the eukaryotic expression spike proteins (rS1 and rS-RBD-mFc) are more suitable than the prokaryotic expression nucleocapsid proteins for serological diagnosis of SARS-CoV-2. The proposed GICA for detection of total antibodies could be a powerful complement to the current RNA tests for COVID-19.


Assuntos
Teste Sorológico para COVID-19/métodos , COVID-19/diagnóstico , SARS-CoV-2/isolamento & purificação , Glicoproteína da Espícula de Coronavírus/imunologia , Anticorpos Antivirais/sangue , COVID-19/sangue , Teste de Ácido Nucleico para COVID-19 , Proteínas do Nucleocapsídeo de Coronavírus/genética , Proteínas do Nucleocapsídeo de Coronavírus/imunologia , Humanos , Imunoensaio , Fosfoproteínas/genética , Fosfoproteínas/imunologia , RNA Viral/genética , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , SARS-CoV-2/genética , SARS-CoV-2/imunologia , Sensibilidade e Especificidade , Glicoproteína da Espícula de Coronavírus/genética
11.
Emerg Microbes Infect ; 9(1): 2368-2378, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33151135

RESUMO

Managing recovered COVID-19 patients with recurrent-positive SARS-CoV-2 RNA test results is challenging. We performed a population-based observational study to characterize the viral RNA level and serum antibody responses in recurrent-positive patients and evaluate their viral transmission risk. Of 479 recovered COVID-19 patients, 93 (19%) recurrent-positive patients were identified, characterized by younger age, with a median discharge-to-recurrent-positive length of 8 days. After readmission, recurrent-positive patients exhibited mild (28%) or absent (72%) symptoms, with no disease progression. The viral RNA level in recurrent-positive patients ranged from 1.8 to 5.7 log10 copies/mL (median: 3.2), which was significantly lower than the corresponding values at disease onset. There are generally no significant differences in antibody levels between recurrent-positive and non-recurrent-positive patients, or in recurrent-positive patients over time (before, during, or after recurrent-positive detection). Virus isolation of nine representative specimens returned negative results. Whole genome sequencing of six specimens yielded only genomic fragments. 96 close contacts and 1,200 candidate contacts of 23 recurrent-positive patients showed no clinical symptoms; their viral RNA (1,296/1,296) and antibody (20/20) tests were negative. After full recovery (no longer/never recurrent-positive), 60% (98/162) patients had neutralizing antibody titers of ≥1:32. Our findings suggested that an intermittent, non-stable excretion of low-level viral RNA may result in recurrent-positive occurrence, rather than re-infection. Recurrent-positive patients pose a low transmission risk, a relatively relaxed management of recovered COVID-19 patients is recommended.


Assuntos
Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Betacoronavirus/isolamento & purificação , Técnicas de Laboratório Clínico/métodos , Infecções por Coronavirus/diagnóstico , Pneumonia Viral/diagnóstico , RNA Viral/análise , Adulto , Betacoronavirus/genética , Betacoronavirus/imunologia , COVID-19 , Teste para COVID-19 , Infecções por Coronavirus/terapia , Infecções por Coronavirus/transmissão , Feminino , Genoma Viral/genética , Humanos , Masculino , Pessoa de Meia-Idade , Pandemias , Pneumonia Viral/terapia , Pneumonia Viral/transmissão , Recidiva , SARS-CoV-2 , Sequenciamento Completo do Genoma , Adulto Jovem
12.
Future Microbiol ; 15: 1207-1215, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-33026884

RESUMO

Aim: The aim of this study was to access the effect of HmsA, a 65-nt small regulatory RNA encoded by the pPCP1 plasmid, on Yersinia pestis virulence. Materials & methods: Survival and the competition index were determined in mice infected with wild-type Y. pestis and an hmsA deletion mutant. RNA-seq was used to identify HmsA-regulated genes. Results: HmsA deletion enhanced Y. pestis virulence. However, there was no overlap between 18 upregulated genes associated with pathogenicity and potential direct HmsA targets, based on gene expression screening after HmsA-pulse overexpression. Conclusion: HmsA inhibits Y. pestis virulence, but this effect may be mediated by indirect effects on pathogenesis, iron homeostasis and/or other cellular processes.

13.
Infect Immun ; 89(1)2020 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-33106294

RESUMO

External environmental factors can cause an imbalance in intestinal flora. For people living in the extremes of a plateau climate, lack of oxygen is a primary health challenge that leads to a series of reactions. We wondered how intestinal microorganisms might change in a simulated plateau environment and what changes might occur in the host organism and intestinal microorganisms in the absence of hypoxia-related factors. In this study, mice carrying a knockout of hypoxia-inducible factor 1ß (Hif-1ß) in myeloid cells and wild-type mice were raised in a composite hypoxic chamber to simulate a plateau environment at 5,000 m of elevation for 14 days. The mice carrying the myeloid Hif-1ß deletion displayed aggravated hypoxic phenotypes in comparison to and significantly greater weight loss and significantly higher cardiac index values than the wild-type group. The levels of some cytokines increased in the hypoxic environment. Analysis of 16S rRNA sequencing results showed that hypoxia had a significant effect on the gut microbiota in both wild-type and Hif-1ß-deficient mice, especially on the first day. The levels of members of the Bacteroidaceae family increased continuously from day 1 to day 14 in Hif-1ß deletion mice, and they represented an obviously different group of bacteria at day 14 compared with the wild-type mice. Butyrate-producing bacteria, such as Butyricicoccus, were found in wild-type mice only after 14 days in the hypoxic environment. In conclusion, hypoxia caused heart enlargement, greater weight loss, and obvious microbial imbalance in myeloid Hif-1ß-deficient mice. This study revealed genetic and microecological pathways for research on mechanisms of hypoxia.


Assuntos
Translocador Nuclear Receptor Aril Hidrocarboneto/deficiência , Microbioma Gastrointestinal , Deleção de Genes , Hipóxia/genética , Células Mieloides/metabolismo , Animais , Biodiversidade , Feminino , Hipóxia/metabolismo , Camundongos , Camundongos Knockout , Células Mieloides/imunologia , Fenótipo
14.
BMC Microbiol ; 20(1): 251, 2020 08 12.
Artigo em Inglês | MEDLINE | ID: mdl-32787788

RESUMO

BACKGROUND: Coxiella burnetii is an obligate intracellular Gram-negative bacterium that causes a zoonotic disease commonly called Q fever globally. In this study, an up-converting phosphor technology-based lateral flow (UPT-LF) assay was established for the rapid and specific detection of phase I strains of C. burnetii. RESULTS: Specific monoclonal antibodies (10B5 and 10G7) against C. burnetii phase I strains were prepared and selected for use in the UPT-LF assay by the double-antibody-sandwich method. The detection sensitivity of the Coxiella-UPT-LF was 5 × 104 GE/ml for a purified C. burnetii phase I strain and 10 ng/ml for LPS of C. burnetii Nine Mile phase I (NMI). Good linearity was observed for C. burnetii phase I and NMI LPS quantification (R2 ≥ 0.989). The UPT-LF assay also exhibited a high specificity to C. burnetii, without false-positive results even at 108 GE/ml of non-specific bacteria, and good inclusivity for detecting different phase I strains of C. burnetii. Moreover, the performance of the Coxiella-UPT-LF assay was further confirmed using experimentally and naturally infected samples. CONCLUSIONS: Our results indicate that Coxiella-UPT-LF is a sensitive and reliable method for rapid screening of C. burnetii, suitable for on-site detection in the field.

15.
Front Microbiol ; 11: 1474, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32714309

RESUMO

Several studies based on 16SrDNA analysis have revealed certain unique characteristics of gut microbiome in centenarians. We established a prospective cohort of fecal microbiota and conducted the first metagenomics-based study among centenarians. The objective was to explore the dynamic changes of gut microbiota in healthy centenarians and centenarians approaching end of life and to unravel the characteristics of aging-associated microbiome. Seventy-five healthy centenarians residing in three regions of Hainan participated in follow-up surveys and collection of fecal samples at intervals of 3 months. Data pertaining to dietary status, health status scores, cause of disease and death, and fecal specimens were collected for 15 months. Twenty participants died within 20 months during the follow-up period. The median survival time was 8-9 months (range, 1-17) and the mortality rate was 14.7% per year. The health status scores before death were significantly lower than those at 3 months before the end of the follow-up period [median score: 3 (range, 1-5), P < 0.05]. At this time, the participants mainly exhibited symptoms of anorexia and reduced dietary intake and physical activity. Metagenomics sequencing and analysis were carried out to characterize the gut microbiota changes in the centenarians during their transition from healthy status to death. Anosim analysis showed a significant change in gut microbiota from 7 months prior to death (R = 0.10, P = 0.02). All participants were grouped with 7 months before death as cut-off; no significant difference in α diversity was found between the two groups (P = 0.45). Semi-supervised monitoring and log rank sum analysis revealed significant changes in the abundance of ten bacterial species before death; of these, eight species were significantly reduced (Akkermansia muciniphila, Alistipes finegoldii, Alistipes shahii, Bacteroides faecis, Bacteroides intestinalis, Butyrivibrio crossotus, Bacteroides stercoris, and Prevotella stercorea) while two were significantly increased before death (Bifidobacterium longum and Ruminococcus bromii). Compared to centenarians in northern Italy, Hainan centenarians exhibited unique characteristics of gut microbiome. The abundance of ten bacterial species showed significant changes starting from 7 months before death. We speculate that these changes might occur before the clinical symptoms of deterioration in health status.

16.
Artigo em Inglês | MEDLINE | ID: mdl-32391285

RESUMO

Yersinia pestis, Brucella spp., and Bacillus anthracis are pathogens that can cause infectious zoonotic diseases with high mortality rates. An upconverting phosphor-based quantitative immunochromatographic (UPT-LF) assay, a point-of-care testing method suitable for resource-limited areas, was calibrated to quantitatively detect pathogenic bacteria. The bacterial purity or activity were ensured via staining methods and growth curves, respectively. Growth assays showed that the classic plate-counting method underestimated bacterial numbers compared with the bacterial counting method recommended by the reference material of the National Institutes for Food and Drug Control, China. The detection results of the UPT-LF assay differed significantly between the bacterial cultures in liquid and solid media and between different strains. Accelerated stability assessments and freeze-thaw experiments showed that the stability of the corresponding antigens played an important role in calibrating the UPT-LF assay. In this study, a new calibration system was developed for quantitative immunochromatography for detecting pathogenic bacteria. The results demonstrated the necessity of calibration for standardizing point-of-care testing methods.


Assuntos
Bacillus anthracis , Brucella , Yersinia pestis , Calibragem , China , Imunoensaio , Sensibilidade e Especificidade , Esporos
17.
Science ; 368(6491): 638-642, 2020 05 08.
Artigo em Inglês | MEDLINE | ID: mdl-32234804

RESUMO

Responding to an outbreak of a novel coronavirus [agent of coronavirus disease 2019 (COVID-19)] in December 2019, China banned travel to and from Wuhan city on 23 January 2020 and implemented a national emergency response. We investigated the spread and control of COVID-19 using a data set that included case reports, human movement, and public health interventions. The Wuhan shutdown was associated with the delayed arrival of COVID-19 in other cities by 2.91 days. Cities that implemented control measures preemptively reported fewer cases on average (13.0) in the first week of their outbreaks compared with cities that started control later (20.6). Suspending intracity public transport, closing entertainment venues, and banning public gatherings were associated with reductions in case incidence. The national emergency response appears to have delayed the growth and limited the size of the COVID-19 epidemic in China, averting hundreds of thousands of cases by 19 February (day 50).


Assuntos
Betacoronavirus , Infecções por Coronavirus/prevenção & controle , Infecções por Coronavirus/transmissão , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Pneumonia Viral/transmissão , Viagem , COVID-19 , China/epidemiologia , Controle de Doenças Transmissíveis , Infecções por Coronavirus/epidemiologia , Epidemias , Humanos , Incidência , Modelos Estatísticos , Pneumonia Viral/epidemiologia , Prática de Saúde Pública , Análise de Regressão , SARS-CoV-2
19.
Elife ; 92020 03 20.
Artigo em Inglês | MEDLINE | ID: mdl-32195663

RESUMO

Investigating fitness interactions in natural populations remains a considerable challenge. We take advantage of the unique population structure of Vibrio parahaemolyticus, a bacterial pathogen of humans and shrimp, to perform a genome-wide screen for coadapted genetic elements. We identified 90 interaction groups (IGs) involving 1,560 coding genes. 82 IGs are between accessory genes, many of which have functions related to carbohydrate transport and metabolism. Only 8 involve both core and accessory genomes. The largest includes 1,540 SNPs in 82 genes and 338 accessory genome elements, many involved in lateral flagella and cell wall biogenesis. The interactions have a complex hierarchical structure encoding at least four distinct ecological strategies. One strategy involves a divergent profile in multiple genome regions, while the others involve fewer genes and are more plastic. Our results imply that most genetic alliances are ephemeral but that increasingly complex strategies can evolve and eventually cause speciation.


Assuntos
Adaptação Fisiológica/genética , Regulação Bacteriana da Expressão Gênica/fisiologia , Vibrio parahaemolyticus/genética , Especiação Genética , Genoma Bacteriano , Estudo de Associação Genômica Ampla
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