RESUMO
Yersinia phage YerA41 is morphologically similar to jumbo bacteriophages. The isolated genomic material of YerA41 could not be digested by restriction enzymes, and used as a template by conventional DNA polymerases. Nucleoside analysis of the YerA41 genomic material, carried out to find out whether this was due to modified nucleotides, revealed the presence of a ca 1 kDa substitution of thymidine with apparent oligosaccharide character. We identified and purified the phage DNA polymerase (DNAP) that could replicate the YerA41 genomic DNA even without added primers. Cryo-electron microscopy (EM) was used to characterize structural details of the phage particle. The storage capacity of the 131 nm diameter head was calculated to accommodate a significantly longer genome than that of the 145 577 bp genomic DNA of YerA41 determined here. Indeed, cryo-EM revealed, in contrast to the 25 Å in other phages, spacings of 33-36 Å between shells of the genomic material inside YerA41 heads suggesting that the heavily substituted thymidine increases significantly the spacing of the DNA packaged inside the capsid. In conclusion, YerA41 appears to be an unconventional phage that packages thymidine-modified genomic DNA into its capsids along with its own DNAP that has the ability to replicate the genome.
Assuntos
Bacteriófagos , Bacteriófagos/química , Bacteriófagos/genética , Capsídeo , Microscopia Crioeletrônica , DNA Viral/genética , DNA Polimerase Dirigida por DNA/genética , Genoma Viral/genética , TimidinaRESUMO
Changes in the gut microbiota may underpin many human diseases, but the mechanisms that are responsible for altering microbial communities remain poorly understood. Antibiotic usage elevates the risk of contracting gastroenteritis caused by Salmonella enterica serovars, increases the duration for which patients shed the pathogen in their faeces, and may on occasion produce a bacteriologic and symptomatic relapse. These antibiotic-induced changes in the gut microbiota can be studied in mice, in which the disruption of a balanced microbial community by treatment with the antibiotic streptomycin leads to an expansion of S. enterica serovars in the large bowel. However, the mechanisms by which streptomycin treatment drives an expansion of S. enterica serovars are not fully resolved. Here we show that host-mediated oxidation of galactose and glucose promotes post-antibiotic expansion of S. enterica serovar Typhimurium (S. Typhimurium). By elevating expression of the gene encoding inducible nitric oxide synthase (iNOS) in the caecal mucosa, streptomycin treatment increased post-antibiotic availability of the oxidation products galactarate and glucarate in the murine caecum. S. Typhimurium used galactarate and glucarate within the gut lumen of streptomycin pre-treated mice, and genetic ablation of the respective catabolic pathways reduced S. Typhimurium competitiveness. Our results identify host-mediated oxidation of carbohydrates in the gut as a mechanism for post-antibiotic pathogen expansion.
Assuntos
Antibacterianos/farmacologia , Metabolismo dos Carboidratos , Interações Hospedeiro-Patógeno/efeitos dos fármacos , Mucosa Intestinal/efeitos dos fármacos , Salmonella typhimurium/efeitos dos fármacos , Salmonella typhimurium/crescimento & desenvolvimento , Estreptomicina/farmacologia , Animais , Metabolismo dos Carboidratos/efeitos dos fármacos , Metabolismo dos Carboidratos/genética , Ceco/efeitos dos fármacos , Ceco/enzimologia , Ceco/microbiologia , Feminino , Galactose/metabolismo , Gastroenterite/microbiologia , Ácido Glucárico/metabolismo , Glucose/metabolismo , Mucosa Intestinal/enzimologia , Mucosa Intestinal/metabolismo , Mucosa Intestinal/microbiologia , Masculino , Camundongos , Óxido Nítrico Sintase Tipo II/genética , Óxido Nítrico Sintase Tipo II/metabolismo , Óperon/genética , Oxirredução/efeitos dos fármacos , Espécies Reativas de Nitrogênio/metabolismo , Salmonella typhimurium/metabolismo , Salmonella typhimurium/patogenicidade , Açúcares Ácidos/metabolismoRESUMO
Endoplasmic reticulum (ER) stress is a major contributor to inflammatory diseases, such as Crohn disease and type 2 diabetes. ER stress induces the unfolded protein response, which involves activation of three transmembrane receptors, ATF6, PERK and IRE1α. Once activated, IRE1α recruits TRAF2 to the ER membrane to initiate inflammatory responses via the NF-κB pathway. Inflammation is commonly triggered when pattern recognition receptors (PRRs), such as Toll-like receptors or nucleotide-binding oligomerization domain (NOD)-like receptors, detect tissue damage or microbial infection. However, it is not clear which PRRs have a major role in inducing inflammation during ER stress. Here we show that NOD1 and NOD2, two members of the NOD-like receptor family of PRRs, are important mediators of ER-stress-induced inflammation in mouse and human cells. The ER stress inducers thapsigargin and dithiothreitol trigger production of the pro-inflammatory cytokine IL-6 in a NOD1/2-dependent fashion. Inflammation and IL-6 production triggered by infection with Brucella abortus, which induces ER stress by injecting the type IV secretion system effector protein VceC into host cells, is TRAF2, NOD1/2 and RIP2-dependent and can be reduced by treatment with the ER stress inhibitor tauroursodeoxycholate or an IRE1α kinase inhibitor. The association of NOD1 and NOD2 with pro-inflammatory responses induced by the IRE1α/TRAF2 signalling pathway provides a novel link between innate immunity and ER-stress-induced inflammation.
Assuntos
Estresse do Retículo Endoplasmático , Inflamação/metabolismo , Proteína Adaptadora de Sinalização NOD1/metabolismo , Proteína Adaptadora de Sinalização NOD2/metabolismo , Transdução de Sinais , Animais , Proteínas da Membrana Bacteriana Externa/metabolismo , Brucella abortus/imunologia , Brucella abortus/patogenicidade , Linhagem Celular , Ditiotreitol/farmacologia , Retículo Endoplasmático/efeitos dos fármacos , Retículo Endoplasmático/patologia , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Endorribonucleases/antagonistas & inibidores , Feminino , Humanos , Imunidade Inata , Inflamação/induzido quimicamente , Interleucina-6/biossíntese , Masculino , Camundongos , Camundongos Endogâmicos C57BL , NF-kappa B/metabolismo , Proteína Adaptadora de Sinalização NOD1/imunologia , Proteína Adaptadora de Sinalização NOD2/imunologia , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Receptores de Reconhecimento de Padrão/metabolismo , Transdução de Sinais/efeitos dos fármacos , Fator 2 Associado a Receptor de TNF/metabolismo , Ácido Tauroquenodesoxicólico/farmacologia , Tapsigargina/farmacologia , Resposta a Proteínas não Dobradas/efeitos dos fármacosRESUMO
BACKGROUND: Infectious diseases continue to play an important role for disease perception, health-economic considerations and public health in Germany. In recent years, infectious diseases have been linked to the development of non-communicable diseases. Analyses of the German National Cohort (GNC) may provide deeper insights into this issue and pave the way for new targeted approaches in disease prevention. OBJECTIVES: The aim was to describe the tools used to assess infectious diseases and to present initial data on infectious disease frequencies, as well as to relate the GNC assessment tools to data collection methods in other studies in Germany. METHODS: As part of the baseline examination, questions regarding infectious diseases were administered using both an interview and a self-administered touchscreen questionnaire. Data from the initial 101,787 GNC participants were analysed. RESULTS: In the interview, 0.2% (HIV/AIDS) to 8.6% (shingles) of respondents reported ever having a medical diagnosis of shingles, postherpetic neuralgia (in cases where shingles was reported), hepatitis B/C, HIV/AIDS, tuberculosis or sepsis if treated in hospital. In the questionnaire, 12% (cystitis) to 81% (upper respiratory tract infections) of respondents reported having experienced at least one occurrence of upper or lower respiratory tract infections, gastrointestinal infections, cystitis or fever within the past 12 months. OUTLOOK: The cross-sectional analyses of data and tools presented here - for example on determinants of susceptibility to self-reported infections - can be anticipated from the year 2021 onward. Beyond that, more extensive research into infectious disease epidemiology will follow, particularly once analyses of GNC biological materials have been performed.
Assuntos
Doenças Transmissíveis/epidemiologia , Estudos de Coortes , Estudos Transversais , Alemanha/epidemiologia , Humanos , Autorrelato , Inquéritos e QuestionáriosRESUMO
Germline-encoded receptors recognizing common pathogen-associated molecular patterns are a central element of the innate immune system and play an important role in shaping the host response to infection. Many of the innate immune molecules central to these signaling pathways are evolutionarily conserved. LysMD3 is a novel molecule containing a putative peptidoglycan-binding domain that has orthologs in humans, mice, zebrafish, flies, and worms. We found that the lysin motif (LysM) of LysMD3 is likely related to a previously described peptidoglycan-binding LysM found in bacteria. Mouse LysMD3 is a type II integral membrane protein that co-localizes with GM130+ structures, consistent with localization to the Golgi apparatus. We describe here two lines of mLysMD3-deficient mice for in vivo characterization of mLysMD3 function. We found that mLysMD3-deficient mice were born at Mendelian ratios and had no obvious pathological abnormalities. They also exhibited no obvious immune response deficiencies in a number of models of infection and inflammation. mLysMD3-deficient mice exhibited no signs of intestinal dysbiosis by 16S analysis or alterations in intestinal gene expression by RNA sequencing. We conclude that mLysMD3 contains a LysM with cytoplasmic orientation, but we were unable to define a physiological role for the molecule in vivo.
Assuntos
Deleção de Genes , Animais , Autoantígenos/análise , Infecções Bacterianas/genética , Infecções Bacterianas/imunologia , Sistemas CRISPR-Cas , Feminino , Imunidade Inata , Inflamação/genética , Inflamação/imunologia , Masculino , Proteínas de Membrana/análise , Camundongos , Micoses/genética , Micoses/imunologia , Filogenia , Viroses/genética , Viroses/imunologiaRESUMO
Th1 cells can be activated by TCR-independent stimuli, but the importance of this pathway in vivo and the precise mechanisms involved require further investigation. Here, we used a simple model of non-cognate Th1 cell stimulation in Salmonella-infected mice to examine these issues. CD4 Th1 cell expression of both IL-18R and DR3 was required for optimal IFN-γ induction in response to non-cognate stimulation, while IL-15R expression was dispensable. Interestingly, effector Th1 cells generated by immunization rather than live infection had lower non-cognate activity despite comparable IL-18R and DR3 expression. Mice lacking T cell intrinsic expression of MyD88, an important adapter molecule in non-cognate T cell stimulation, exhibited higher bacterial burdens upon infection with Salmonella, Chlamydia or Brucella, suggesting that non-cognate Th1 stimulation is a critical element of efficient bacterial clearance. Thus, IL-18R and DR3 are critical players in non-cognate stimulation of Th1 cells and this response plays an important role in protection against intracellular bacteria.
Assuntos
Infecções Bacterianas/imunologia , Ativação Linfocitária/imunologia , Receptores de Interleucina-18/biossíntese , Membro 25 de Receptores de Fatores de Necrose Tumoral/biossíntese , Células Th1/imunologia , Animais , Modelos Animais de Doenças , Ensaio de Imunoadsorção Enzimática , Citometria de Fluxo , Interleucina-18/metabolismo , Camundongos , Análise de Sequência com Séries de Oligonucleotídeos , Receptores de Interleucina-18/imunologia , Membro 25 de Receptores de Fatores de Necrose Tumoral/imunologia , Células Th1/metabolismoRESUMO
Treatment of intracellular bacterial pathogens with antibiotic therapy often requires a long course of multiple drugs. A barrier to developing strategies that enhance antibiotic efficacy against these pathogens is our poor understanding of the intracellular nutritional environment that maintains bacterial persistence. The intracellular pathogen Brucella abortus survives and replicates preferentially in alternatively activated macrophages (AAMs); however, knowledge of the metabolic adaptations promoting exploitation of this niche is limited. Here we show that one mechanism promoting enhanced survival in AAMs is a shift in macrophage arginine utilization from production of nitric oxide (NO) to biosynthesis of polyamines, induced by interleukin 4 (IL-4)/IL-13 treatment. Production of polyamines by infected AAMs promoted both intracellular survival of B. abortus and chronic infection in mice, as inhibition of macrophage polyamine synthesis or inactivation of the putative putrescine transporter encoded by potIHGF reduced both intracellular survival in AAMs and persistence in mice. These results demonstrate that increased intracellular availability of polyamines induced by arginase-1 expression in IL-4/IL-13-induced AAMs promotes chronic persistence of B. abortus within this niche and suggest that targeting of this pathway may aid in eradicating chronic infection.
Assuntos
Brucella abortus/fisiologia , Brucelose/microbiologia , Macrófagos/fisiologia , Poliaminas/metabolismo , Animais , Antígeno CD11b/genética , Antígeno CD11b/metabolismo , Feminino , Camundongos , Camundongos Endogâmicos BALB C , Baço/citologiaRESUMO
A subset of bacterial pathogens, including the zoonotic Brucella species, are highly resistant against polymyxin antibiotics. Bacterial polymyxin resistance has been attributed primarily to the modification of lipopolysaccharide; however, it is unknown what additional mechanisms mediate high-level resistance against this class of drugs. This work identified a role for the Brucella melitensis gene bveA (BMEII0681), encoding a predicted esterase, in the resistance of B. melitensis to polymyxin B. Characterization of the enzymatic activity of BveA demonstrated that it is a phospholipase A1 with specificity for phosphatidylethanolamine (PE). Further, lipidomic analysis of B. melitensis revealed an excess of PE lipids in the bacterial membranes isolated from the bveA mutant. These results suggest that by lowering the PE content of the cell envelope, BveA increases the resistance of B. melitensis to polymyxin B. BveA was required for survival and replication of B. melitensis in macrophages and for persistent infection in mice. BveA family esterases are encoded in the genomes of the alphaproteobacterial species that coexist with the polymyxin-producing bacteria in the rhizosphere, suggesting that maintenance of a low PE content in the bacterial cell envelope may be a shared persistence strategy for association with plant and mammalian hosts.
Assuntos
Antibacterianos/farmacologia , Brucella melitensis/efeitos dos fármacos , Brucella melitensis/enzimologia , Fosfolipases A1/metabolismo , Fosfolipídeos/metabolismo , Polimixinas/farmacologia , Brucella melitensis/metabolismo , Farmacorresistência Bacteriana , Fosfatidiletanolaminas/metabolismo , Fosfolipases A1/genéticaRESUMO
The majority of Hepatitis E Virus (HEV)-related studies are carried out in adults whereas information about HEV seroprevalence, clinical disease manifestation, molecular epidemiology, and transmission patterns in children is limited. To estimate HEV seroprevalence among scholar children living in an urban setting and to analyze risk factors for an infection, we invited children aged 5-18 years from Bogotá (Colombia) for a cross-sectional survey. We collected self-reported data on demographics, social, clinical, and exposure variables in a structured interview. Venous blood samples were analyzed with two commercially available ELISAs for HEV-specific IgG antibodies. Among the 263 participants, we found three HEV IgG-reactive samples (1.1%) using both assays. We additionally characterized the samples for HEV IgM using a commercially available IgM ELISA and for HEV RNA. Here, we found one IgM-reactive sample, which was also reactive for IgG. In contrast, none of the IgM- and IgG-reactive sera samples showed detectable RNA levels indicating HEV exposure had not been recently. All participants reported access to drinking water and sanitary systems in their households and frequent hand washing routines (76-88%). Eighty percent of children reported no direct contact with pigs, but occasional pork consumption was common (90%). In contrast to the majority of studies performed in Colombian adults, we found a low unadjusted HEV seroprevalence of 1.1% (95% CI: 0.3-3.6%) for both HEV IgG ELISAs in our study population. While the majority of participants reported pork consumption, we speculate in the absence of viral RNA for genotyping in the affected individuals, that existing access to drinking water and sanitary systems within our study group contribute to the low HEV seroprevalence.
Assuntos
Água Potável , Vírus da Hepatite E , Hepatite E , Humanos , Criança , Animais , Suínos , Estudos Transversais , Hepatite E/epidemiologia , Estudos Soroepidemiológicos , Colômbia , Anticorpos Anti-Hepatite , RNA Viral , Imunoglobulina G , Imunoglobulina MRESUMO
Lyme borreliosis (LB) is caused by the transmission of Borrelia burgdorferi s.l. from ticks to humans. Climate affects tick abundance, and climate change is projected to promote shifts in abundance in Europe, potentially increasing human exposure. We analyzed serum samples collected between the years 2014-2019 from German National Cohort (NAKO) participants at four study sites (Augsburg, Berlin, Hanover, Münster) for immunoglobulin G (IgG) and immunoglobulin M (IgM) antibodies using an enzyme-linked immunosorbent assay (ELISA) and line blot immunoassay as confirmatory test for positive and equivocal ELISA samples. We reported crude and weighted seropositivity proportions for local estimates. We used mixed model analysis to investigate associated factors, such as age, sex, migration background, or animal contacts. We determined the serostatus of 14,207 participants. The weighted seropositivity proportions were 3.4% (IgG) and 0.4% (IgM) in Augsburg, 4.1% (IgG) and 0.6% (IgM) in northern Berlin, 3.0% (IgG) and 0.9% (IgM) in Hanover, and 2.7% (IgG) and 0.6% (IgM) in Münster. We found higher odds for IgG seropositivity with advancing age (p < 0.001), among males compared to females (p < 0.001) and reduced odds among participants with migration background compared to those without (p = 0.001). We did not find evidence for an association between serostatus and depression, children within the household, or animal contact, respectively. We found low seropositivity proportions and indications of differences across the study locations, although between-group comparisons did not yield significant results. Comparisons to earlier research are subject to important limitations; however, our results indicate no major increases in seropositivity over time. Nevertheless, monitoring of seropositivity remains critical in light of potential climate-related Borrelia exposure.
Assuntos
Borrelia burgdorferi , Doença de Lyme , Carrapatos , Masculino , Criança , Feminino , Animais , Humanos , Anticorpos Antibacterianos , Doença de Lyme/epidemiologia , Ensaio de Imunoadsorção Enzimática/métodos , Alemanha/epidemiologia , Imunoglobulina G , Imunoglobulina MRESUMO
While flagella-independent motility has long been described in representatives of the genus Acinetobacter, the mechanism of motility remains ambiguous. Acinetobacter baumannii, a nosocomial pathogen appearing increasingly multidrug-resistant, may profit from motility during infection or while persisting in the hospital environment. However, data on the frequency of motility skills among clinical A. baumannii isolates is scarce. We have screened a collection of 83 clinical A. baumannii isolates of different origin and found that, with the exception of one isolate, all were motile on wet surfaces albeit to varying degrees and exhibiting differing morphologies. Screening a collection of transposon mutants of strain ATCC 17978 for motility defects, we identified 2 akinetic mutants carrying transposon insertions in the dat and ddc gene, respectively. These neighbouring genes contribute to synthesis of 1,3-diaminopropane (DAP), a polyamine ubiquitously produced in Acinetobacter. Supplementing semi-solid media with DAP cured the motility defect of both mutants. HPLC analyses confirmed that DAP synthesis was abolished in ddc and dat mutants of different A. baumannii isolates and was re-established after genetic complementation. Both, the dat and ddc mutant of ATCC 17978 were attenuated in the Galleria mellonella caterpillar infection model. Taken together, surface-associated motility is a common trait of clinical A. baumannii isolates that requires DAP and may play a role in its virulence.
Assuntos
Acinetobacter baumannii/fisiologia , Diaminas/metabolismo , Locomoção , Infecções por Acinetobacter/microbiologia , Acinetobacter baumannii/genética , Acinetobacter baumannii/isolamento & purificação , Animais , Cromatografia Líquida de Alta Pressão , Elementos de DNA Transponíveis , Técnicas de Inativação de Genes , Teste de Complementação Genética , Humanos , Lepidópteros , Redes e Vias Metabólicas/genética , Mutagênese Insercional , Virulência , Fatores de Virulência/metabolismoRESUMO
Lyme borreliosis is the leading tick-related illness in Europe, caused by Borrelia Burgdorferi s.l. Lower Saxony, Germany, including its capital, Hanover, has a higher proportion of infected ticks than central European countries, justifying a research focus on the potential human consequences. The current knowledge gap on human incident infections, particularly in Western Germany, demands serological insights, especially regarding a potentially changing climate-related tick abundance and activity. We determined the immunoglobulin G (IgG) and immunoglobulin M (IgM) serostatuses for 8009 German National Cohort (NAKO) participants from Hanover, examined in 2014-2018. We used an enzyme-linked immunosorbent assay (ELISA) as the screening and a line immunoblot as confirmation for the Borrelia Burgdorferi s.l. antibodies. We weighted the seropositivity proportions to estimate general population seropositivity and estimated the force of infection (FOI). Using logistic regression, we investigated risk factors for seropositivity. Seropositivity was 3.0% (IgG) and 2.1% (IgM). The FOI varied with age, sharply increasing in participants aged ≥40 years. We confirmed advancing age and male sex as risk factors. We reported reduced odds for seropositivity with increasing body mass index and depressive symptomatology, respectively, pointing to an impact of lifestyle-related behaviors. The local proportion of seropositive individuals is comparable to previous estimates for northern Germany, indicating a steady seroprevalence.
RESUMO
BACKGROUND: Lyme borreliosis is the most prevalent vector-borne disease in Europe, and numbers might increase due to climate change. However, borreliosis is not notifiable in North Rhine-Westphalia (NRW), Germany. Hence, little is known about the current human seroprevalence in NRW. However, the proportion of Borrelia burgdorferi sensu lato-infected ticks has increased in a NRW nature reserve. The literature suggests increasing age and male sex as risk factors for seropositivity, whereas the influence of socioeconomic status is controversial. Thus, we aimed to determine regional seropositivity for Borrelia burgdorferi sensu lato (B. burgdorferi s.l.) and its risk factors in the Rhineland Study population in Bonn, NRW, and to compare it with previous surveys to evaluate potential effects of climate change. METHODS: We assessed seropositivity in 2865 Rhineland Study participants by determining immunoglobulin G (IgG) and immunoglobulin M (IgM) antibodies for B. burgdorferi s.l. using a two-step algorithm combining enzyme-linked immunosorbent assay tests and line immunoblots. We calculated the odds of being classified as IgG or IgM positive as a function of age, sex, and educational level using binomial logistic regression models. We applied varying seropositivity classifications and weights considering age, sex and education to compensate for differences between the sample and regional population characteristics. RESULTS: IgG antibodies for B. burgdorferi s.l. were present in 2.4% and IgM antibodies in 0.6% of the participants (weighted: 2.2% [IgG], 0.6% [IgM]). The likelihood of IgG seropositivity increased by 3.0% (95% confidence interval [CI] 1.5-5.2%) per 1 year increase in age. Men had 1.65 times the odds for IgG seropositivity as women (95% CI 1.01-2.73), and highly educated participants had 1.83 times the odds (95% CI 1.10-3.14) as participants with an intermediate level of education. We found no statistically significant link between age, sex, or education and IgM seropositivity. Our weighted and age-standardized IgG seroprevalence was comparable to the preceding serosurvey German Health Interview and Examination Survey for Adults (DEGS) for NRW. CONCLUSIONS: We confirmed that increasing age and male sex are associated with increased odds for IgG seropositivity and provide evidence for increased seropositivity in the highly educated group. B. burgdorferi s.l. seropositivity remained constant over the past decade in this regional German population.
Assuntos
Borrelia burgdorferi , Adulto , Feminino , Alemanha/epidemiologia , Humanos , Imunoglobulina G , Imunoglobulina M , Masculino , Estudos SoroepidemiológicosRESUMO
Recent increases in SARS-CoV-2 infections have led to questions about duration and quality of vaccine-induced immune protection. While numerous studies have been published on immune responses triggered by vaccination, these often focus on studying the impact of one or two immunisation schemes within subpopulations such as immunocompromised individuals or healthcare workers. To provide information on the duration and quality of vaccine-induced immune responses against SARS-CoV-2, we analyzed antibody titres against various SARS-CoV-2 antigens and ACE2 binding inhibition against SARS-CoV-2 wild-type and variants of concern in samples from a large German population-based seroprevalence study (MuSPAD) who had received all currently available immunisation schemes. We found that homologous mRNA-based or heterologous prime-boost vaccination produced significantly higher antibody responses than vector-based homologous vaccination. Ad26.CoV2S.2 performance was particularly concerning with reduced titres and 91.7% of samples classified as non-responsive for ACE2 binding inhibition, suggesting that recipients require a booster mRNA vaccination. While mRNA vaccination induced a higher ratio of RBD- and S1-targeting antibodies, vector-based vaccines resulted in an increased proportion of S2-targeting antibodies. Given the role of RBD- and S1-specific antibodies in neutralizing SARS-CoV-2, their relative over-representation after mRNA vaccination may explain why these vaccines have increased efficacy compared to vector-based formulations. Previously infected individuals had a robust immune response once vaccinated, regardless of which vaccine they received, which could aid future dose allocation should shortages arise for certain manufacturers. Overall, both titres and ACE2 binding inhibition peaked approximately 28 days post-second vaccination and then decreased.
Assuntos
Ad26COVS1/imunologia , COVID-19/imunologia , Imunidade Humoral/imunologia , SARS-CoV-2/crescimento & desenvolvimento , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Formação de Anticorpos/imunologia , Estudos Transversais , Alemanha , Humanos , Estudos Soroepidemiológicos , Glicoproteína da Espícula de Coronavírus/imunologia , Vacinação/métodosRESUMO
BACKGROUND: Until now, information on the spread of SARS-CoV-2 infections in Germany has been based mainly on data from the public health offices. It may be assumed that these data do not include many cases of asymptomatic and mild infection. METHODS: We determined seroprevalence over the course of the pandemic in a sequential, multilocal seroprevalence study (MuSPAD). Study participants were recruited at random in seven administrative districts (Kreise) in Germany from July 2020 onward; each participant was tested at two different times 3-5 months apart. Test findings on blood samples were used to determine the missed-case rate of reported infections, the infection fatality rate (IFR), and the association between seropositivity and demographic, socio-economic, and health-related factors, as well as to evaluate the self-reported results of PCR and antigenic tests. The registration number of this study is DRKS00022335. RESULTS: Among non-vaccinated persons, the seroprevalence from July to December 2020 was 1.3-2.8% and rose between February and May 2021 to 4.1-13.1%. In July 2021, 35% of tested persons in Chemnitz were not vaccinated, and the seroprevalence among these persons was 32.4% (07/2021). The surveillance detection ratio (SDR), i.e., the ratio between the true number of infections estimated from seroprevalence and the actual number or reported infections, varied among the districts included in the study from 2.2 to 5.1 up to December 2020 and from 1.3 to 2.9 up to June 2021, and subsequently declined. The IFR was in the range of 0.8% to 2.4% in all regions except Magdeburg, where a value of 0.3% was calculated for November 2020. A lower educational level was associated with a higher seropositivity rate, smoking with a lower seropositivity rate. On average, 1 person was infected for every 8.5 persons in quarantine. CONCLUSION: Seroprevalence was low after the first wave of the pandemic but rose markedly during the second and third waves. The missed-case rate trended downward over the course of the pandemic.
Assuntos
COVID-19 , SARS-CoV-2 , Alemanha/epidemiologia , Humanos , Pandemias , Estudos SoroepidemiológicosRESUMO
The humoral immune response to SARS-CoV-2 is a benchmark for immunity and detailed analysis is required to understand the manifestation and progression of COVID-19, monitor seroconversion within the general population, and support vaccine development. The majority of currently available commercial serological assays only quantify the SARS-CoV-2 antibody response against individual antigens, limiting our understanding of the immune response. To overcome this, we have developed a multiplex immunoassay (MultiCoV-Ab) including spike and nucleocapsid proteins of SARS-CoV-2 and the endemic human coronaviruses. Compared to three broadly used commercial in vitro diagnostic tests, our MultiCoV-Ab achieves a higher sensitivity and specificity when analyzing a well-characterized sample set of SARS-CoV-2 infected and uninfected individuals. We find a high response against endemic coronaviruses in our sample set, but no consistent cross-reactive IgG response patterns against SARS-CoV-2. Here we show a robust, high-content-enabled, antigen-saving multiplex assay suited to both monitoring vaccination studies and facilitating epidemiologic screenings for humoral immunity towards pandemic and endemic coronaviruses.
Assuntos
Anticorpos Antivirais/imunologia , Teste Sorológico para COVID-19/métodos , COVID-19/imunologia , Reações Cruzadas , Imunidade Humoral , COVID-19/diagnóstico , Proteínas do Nucleocapsídeo de Coronavírus/imunologia , Humanos , Imunoensaio , Imunoglobulina G/imunologia , Fosfoproteínas/imunologia , SARS-CoV-2/imunologia , Sensibilidade e Especificidade , Glicoproteína da Espícula de Coronavírus/imunologiaRESUMO
A novel gammaproteobacterium, strain CN3(T), was isolated from the faeces of wild boar. Strain CN3(T) was facultatively anaerobic and appeared coccoid or rod-shaped. The partial 16S rRNA gene sequence determined for strain CN3(T) suggested a distant relationship with members of the orders 'Enterobacteriales' and Pasteurellales. The gene sequence showed highest similarity (90.3â%) with Obesumbacterium proteus DSM 2777(T), a member of the family Enterobacteriaceae. The closest relatives outside the order 'Enterobacteriales' according to 16S rRNA gene sequence analysis were members of the order Pasteurellales with 88.7â% similarity (Mannheimia haemolytica NCTC 9380(T) and Actinobacillus lignieresii NCTC 4189(T)). In contrast to most members of the order 'Enterobacteriales', strain CN3(T) was oxidase-positive. The pattern of fatty acids, in particular the high relative abundance of C(18â:â1)ω7c (38.5â%), was clearly distinct from the conserved pattern found for members of the order Pasteurellales. EcoRI ribotyping of strain CN3(T) yielded no significant similarity to existing database entries. The major ubiquinone of strain CN3(T) was Q-8. The DNA G+C content was 36.4 mol%. Strain CN3(T) hosted a phage and secreted considerable amounts of three proteins into the culture supernatant. A spontaneous mutant of strain CN3(T) was isolated which formed long filaments. Microscopic studies revealed the presence of a capsule that the mutant strain was unable to partition after cell division. Strain CN3(T) thus represents a novel species within a new genus, for which the name Orbus hercynius gen. nov., sp. nov. is proposed. The type strain of the type species is CN3(T) (=DSM 22228(T)=CCUG 57622(T)). Classification of the novel species to the family and order level will require further investigations.
Assuntos
Fezes/microbiologia , Gammaproteobacteria/classificação , Gammaproteobacteria/isolamento & purificação , Sus scrofa/microbiologia , Animais , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/metabolismo , Gammaproteobacteria/genética , Gammaproteobacteria/metabolismo , Dados de Sequência Molecular , Filogenia , RNA Ribossômico 16S/genéticaRESUMO
Preservation of blood plasma in the dried state would facilitate long-term storage and transport at ambient temperatures, without the need of to use liquid nitrogen tanks or freezers. The aim of this study was to investigate the feasibility of dry preservation of human plasma, using sugars as lyoprotectants, and evaluate macromolecular stability of plasma components during storage. Blood plasma from healthy donors was freeze dried using 0-10% glucose, sucrose, or trehalose, and stored at various temperatures. Differential scanning calorimetry was used to measure the glass transition temperatures of freeze-dried samples. Protein aggregation, the overall protein secondary structure, and oxidative damage were studied under different storage conditions. Differential scanning calorimetry measurements showed that plasma freeze-dried with glucose, sucrose and trehalose have glass transition temperatures of respectively 72±3.4°C, 46±11°C, 15±2.4°C. It was found that sugars diminish freeze-drying induced protein aggregation in a dose-dependent manner, and that a 10% (w/v) sugar concentration almost entirely prevents protein aggregation. Protein aggregation after rehydration coincided with relatively high contents of ß-sheet structures in the dried state. Trehalose reduced the rate of protein aggregation during storage at elevated temperatures, and plasma that is freeze- dried plasma with trehalose showed a reduced accumulation of reactive oxygen species and protein oxidation products during storage. In conclusion, freeze-drying plasma with trehalose provides an attractive alternative to traditional cryogenic preservation.
Assuntos
Proteínas Sanguíneas/metabolismo , Plasma/química , Preservação Biológica/métodos , Conservantes Farmacêuticos/química , Trealose/química , Proteínas Sanguíneas/química , Estabilidade de Medicamentos , Armazenamento de Medicamentos , Liofilização , Humanos , Agregados Proteicos , Conformação Proteica em Folha beta , Estabilidade Proteica , Temperatura de Transição , VitrificaçãoRESUMO
Immunostimulation by chronic infection has been linked to an increased risk for different non-communicable diseases, which in turn are leading causes of death in high- and middle-income countries. Thus, we investigated if a positive serostatus for pathogens responsible for common chronic infections is individually or synergistically related to reduced overall survival in community dwelling elderly. We used data of 365 individuals from the German MEMO (Memory and Morbidity in Augsburg Elderly) cohort study with a median age of 73 years at baseline and a median follow-up of 14 years. We examined the effect of a positive serostatus at baseline for selected pathogens associated with chronic infections (Helicobacter pylori, Borrelia burgdorferi sensu lato, Toxoplasma gondii, cytomegalovirus, Epstein-Barr virus, herpes simplex virus 1/2, and human herpesvirus 6) on all-cause mortality with multivariable parametric survival models. We found a reduced survival time in individuals with a positive serostatus for Helicobacter pylori (accelerated failure time (AFT) - 15.92, 95% CI - 29.96; - 1.88), cytomegalovirus (AFT - 22.81, 95% CI - 36.41; - 9.22) and Borrelia burgdorferi sensu lato (AFT - 25.25, 95% CI - 43.40; - 7.10), after adjusting for potential confounders. The number of infectious agents an individual was seropositive for had a linear effect on all-cause mortality (AFT per additional infection - 12.42 95% CI - 18.55; - 6.30). Our results suggest an effect of seropositivity for Helicobacter pylori, cytomegalovirus, and Borrelia burgdorferi sensu lato on all-cause mortality in older community dwelling individuals. Further research with larger cohorts and additional biomarkers is required, to assess mediators and molecular pathways of this effect.
Assuntos
Infecções por Vírus Epstein-Barr , Idoso , Estudos de Coortes , Infecções por Vírus Epstein-Barr/complicações , Infecções por Vírus Epstein-Barr/epidemiologia , Herpesvirus Humano 4 , Humanos , Morbidade , Fatores de RiscoRESUMO
The virulence-associated effector protein AvrA of Salmonella enterica is an ubiquitin-like acetyltransferase/cysteine protease, which interferes with the first line of immune response of the target organism. In contrast to translation of the AvrA protein in S. enterica strains, which takes place either constitutively (class 1 strains), or after acid induction (class 2 strains), or not at all (class 3 strains); the constitutive transcription of the respective avrA genes occurs regardless of these defined expression classes. When the number of avrA genes and mRNA molecules is raised experimentally using plasmids carrying the respective cloned avrA genes together with their promoter regions, the translation of avrA mRNA takes place very strongly in all respective AvrA expression classes. This kind of copy-dependent, post-transcriptional control of AvrA was shown to be dependent on the regulatory action of the CsrA/CsrB system since the deletion of both genes completely abolished the translation in the tested S. enterica strains, whereas the transcription remained unaffected. Moreover, AvrA production in strains carrying the cloned avrA genes on plasmids remained dependent on the presence of CsrA but unaffected in csrB mutant strains. On the other hand, overproduction of the regulatory molecules CsrA and CsrB in S. enterica strains carrying cloned csrA and csrB genes on plasmids ceased the expression of AvrA again. Therefore, the expression of avrA is suggested to be regulated in a post-transcriptional manner by critical and effective concentrations of CsrA (see-saw regulation), which is achieved through the sequestering activity of CsrB.