115 research outputs found
Dinâmica ovariana e taxa de gestação em vacas inseminadas artificialmente em tempo fixo sob diferentes metodologias.
Ovarian dynamics and pregnancy rate in cows inseminated artificially fixed in time under different methodologies
Novel phages of healthy skin metaviromes from South Africa
Recent skin metagenomic studies have investigated the harbored viral diversity and its possible
influence on healthy skin microbial populations, and tried to establish global patterns of skin-phage
evolution. However, the detail associated with the phages that potentially play a role in skin health
has not been investigated. While skin metagenome and -metavirome studies have indicated that the
skin virome is highly site specific and shows marked interpersonal variation, they have not assessed
the presence/absence of individual phages. Here, we took a semi-culture independent approach
(metaviromic) to better understand the composition of phage communities on skin from South African
study participants. Our data set adds over 130 new phage species of the skin to existing databases.
We demonstrated that identical phages were present on different individuals and in different body
sites, and we conducted a detailed analysis of the structural organization of these phages. We further
found that a bacteriophage related to the Staphylococcus capitis phage Stb20 may be a common skin
commensal virus potentially regulating its host and its activities on the ski
Pickering emulsions stabilized with curcumin-based solid dispersion particles as mayonnaise-like food sauce alternatives
Pickering emulsions, which are emulsions stabilized by colloidal particles, are being
increasingly positioned as novel strategies to develop innovative food product solutions. In this
context, the present work aims to develop Pickering emulsions stabilized by natural-based curcuminloaded
particles produced by the solid dispersion technique as promising mayonnaise-like food
sauce alternatives. Two particle formulations (KC1 and KC2) were produced using k-carrageenan
as the matrix material and different curcumin contents, then employed in the preparation of three
Pickering emulsion formulations comprising different oil fractions (') and particle concentrations
(KC1 ' 0.4 (4.7%), KC2 ' 0.4 (4.7%) and KC2 ' 0.6 (4.0%)). The creaming index tests accompanied
by the optical microscopy analysis evidenced the good stability of the developed products for the
tested period of 28 days. The final products were tested concerning color attributes, pH, oxidative
stability, textural, and nutritional composition, and compared with two commercial mayonnaises
(traditional and light products). Overall, the produced emulsions were characterized by a bright
yellow color (an appealing attribute for consumers), an acidic pH (similar to mayonnaise), and a
considerably improved oxidative stability, implying a foreseeable longer shelf life. The sauce KC1 '
0.4 (4.7%) showed a similar texture to the light commercial mayonnaise, being a promising alternative
to conventional sauces, holding a low-fat content and potentially added benefits due to the curcumin
and virgin olive oil intrinsic properties.The authors are grateful to the Foundation for Science and Technology (FCT, Portugal)
and FEDER under Programme PT2020 for financial support to CIMO (UIDB/00690/2020) and
LSRE-LCM (UIDB/50020/2020). Promove program of the “la Caixa” Foundation and BPI. National
funding by FCT, P.I., through the institutional scientific employment program-contract for Arantzazu
Santamaria-Echart, Nuno Rodrigues, Márcio Carocho, and Lillian Barros. FCT for the Research grant
SFRH/BD/147326/2019 of Stephany C. de Rezende.info:eu-repo/semantics/publishedVersio
Analysis of meiotic recombination in 22q11.2, a region that frequently undergoes deletions and duplications
BACKGROUND: The 22q11.2 deletion syndrome is the most frequent genomic disorder with an estimated frequency of 1/4000 live births. The majority of patients (90%) have the same deletion of 3 Mb (Typically Deleted Region, TDR) that results from aberrant recombination at meiosis between region specific low-copy repeats (LCRs). METHODS: As a first step towards the characterization of recombination rates and breakpoints within the 22q11.2 region we have constructed a high resolution recombination breakpoint map based on pedigree analysis and a population-based historical recombination map based on LD analysis. RESULTS: Our pedigree map allows the location of recombination breakpoints with a high resolution (potential recombination hotspots), and this approach has led to the identification of 5 breakpoint segments of 50 kb or less (8.6 kb the smallest), that coincide with historical hotspots. It has been suggested that aberrant recombination leading to deletion (and duplication) is caused by low rates of Allelic Homologous Recombination (AHR) within the affected region. However, recombination rate estimates for 22q11.2 region show that neither average recombination rates in the 22q11.2 region or within LCR22-2 (the LCR implicated in most deletions and duplications), are significantly below chromosome 22 averages. Furthermore, LCR22-2, the repeat most frequently implicated in rearrangements, is also the LCR22 with the highest levels of AHR. In addition, we find recombination events in the 22q11.2 region to cluster within families. Within this context, the same chromosome recombines twice in one family; first by AHR and in the next generation by NAHR resulting in an individual affected with the del22q11.2 syndrome. CONCLUSION: We show in the context of a first high resolution pedigree map of the 22q11.2 region that NAHR within LCR22 leading to duplications and deletions cannot be explained exclusively under a hypothesis of low AHR rates. In addition, we find that AHR recombination events cluster within families. If normal and aberrant recombination are mechanistically related, the fact that LCR22s undergo frequent AHR and that we find familial differences in recombination rates within the 22q11.2 region would have obvious health-related implications
Neisseria gonorrhoeae sequence typing for antimicrobial resistance, a novel antimicrobial resistance multilocus typing scheme for tracking global dissemination of N. Gonorrhoeae strains
A curated Web-based user-friendly sequence typing tool based on antimicrobial resistance determinants in Neisseria gonorrhoeae was developed and is publicly accessible (https://ngstar.Canada.ca). The N. gonorrhoeae Sequence Typing for Antimicrobial Resistance (NG-STAR) molecular typing scheme uses the DNA sequences of 7 genes (penA, mtrR, porB, ponA, gyrA, parC, and 23S rRNA) associated with resistance to β-lactam antimicrobials, macrolides, or fluoroquinolones. NG-STAR uses the entire penA sequence, combining the historical nomenclature for penA types I to XXXVIII with novel nucleotide sequence designations; the full mtrR sequence and a portion of its promoter region; portions of ponA, porB, gyrA, and parC; and 23S rRNA sequences. NG-STAR grouped 768 isolates into 139 sequence types (STs) (n = 660) consisting of 29 clonal complexes (CCs) having a maximum of a single-locus variation, and 76 NG-STAR STs (n = 109) were identified as unrelated singletons. NG-STAR had a high Simpson's diversity index value of 96.5% (95% confidence interval [CI] = 0.959 to 0.969). The most common STs were NG-STAR ST-90 (n = 100; 13.0%), ST-42 and ST-91 (n = 45; 5.9%), ST-64 (n = 44; 5.72%), and ST-139 (n = 42; 5.5%). Decreased susceptibility to azithromycin was associated with NGSTAR ST-58, ST-61, ST-64, ST-79, ST-91, and ST-139 (n = 156; 92.3%); decreased susceptibility to cephalosporins was associated with NG-STAR ST-90, ST-91, and ST-97 (n = 162; 94.2%); and ciprofloxacin resistance was associated with NG-STAR ST-26, ST-90, ST-91, ST-97, ST-150, and ST-158 (n = 196; 98.0%). All isolates of NG-STAR ST- 42, ST-43, ST-63, ST-81, and ST-160 (n = 106) were susceptible to all four antimicrobials. The standardization of nomenclature associated with antimicrobial resistance determinants through an internationally available database will facilitate the monitoring of the global dissemination of antimicrobial-resistant N. gonorrhoeae strains
Prophage exotoxins enhance colonization fitness in epidemic scarlet fever-causing Streptococcus pyogenes
Abstract: The re-emergence of scarlet fever poses a new global public health threat. The capacity of North-East Asian serotype M12 (emm12) Streptococcus pyogenes (group A Streptococcus, GAS) to cause scarlet fever has been linked epidemiologically to the presence of novel prophages, including prophage ΦHKU.vir encoding the secreted superantigens SSA and SpeC and the DNase Spd1. Here, we report the molecular characterization of ΦHKU.vir-encoded exotoxins. We demonstrate that streptolysin O (SLO)-induced glutathione efflux from host cellular stores is a previously unappreciated GAS virulence mechanism that promotes SSA release and activity, representing the first description of a thiol-activated bacterial superantigen. Spd1 is required for resistance to neutrophil killing. Investigating single, double and triple isogenic knockout mutants of the ΦHKU.vir-encoded exotoxins, we find that SpeC and Spd1 act synergistically to facilitate nasopharyngeal colonization in a mouse model. These results offer insight into the pathogenesis of scarlet fever-causing GAS mediated by prophage ΦHKU.vir exotoxins
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Trends in invasive bacterial diseases during the first 2 years of the COVID-19 pandemic: analyses of prospective surveillance data from 30 countries and territories in the IRIS Consortium.
BACKGROUND: The Invasive Respiratory Infection Surveillance (IRIS) Consortium was established to assess the impact of the COVID-19 pandemic on invasive diseases caused by Streptococcus pneumoniae, Haemophilus influenzae, Neisseria meningitidis, and Streptococcus agalactiae. We aimed to analyse the incidence and distribution of these diseases during the first 2 years of the COVID-19 pandemic compared to the 2 years preceding the pandemic. METHODS: For this prospective analysis, laboratories in 30 countries and territories representing five continents submitted surveillance data from Jan 1, 2018, to Jan 2, 2022, to private projects within databases in PubMLST. The impact of COVID-19 containment measures on the overall number of cases was analysed, and changes in disease distributions by patient age and serotype or group were examined. Interrupted time-series analyses were done to quantify the impact of pandemic response measures and their relaxation on disease rates, and autoregressive integrated moving average models were used to estimate effect sizes and forecast counterfactual trends by hemisphere. FINDINGS: Overall, 116 841 cases were analysed: 76 481 in 2018-19, before the pandemic, and 40 360 in 2020-21, during the pandemic. During the pandemic there was a significant reduction in the risk of disease caused by S pneumoniae (risk ratio 0·47; 95% CI 0·40-0·55), H influenzae (0·51; 0·40-0·66) and N meningitidis (0·26; 0·21-0·31), while no significant changes were observed for S agalactiae (1·02; 0·75-1·40), which is not transmitted via the respiratory route. No major changes in the distribution of cases were observed when stratified by patient age or serotype or group. An estimated 36 289 (95% prediction interval 17 145-55 434) cases of invasive bacterial disease were averted during the first 2 years of the pandemic among IRIS-participating countries and territories. INTERPRETATION: COVID-19 containment measures were associated with a sustained decrease in the incidence of invasive disease caused by S pneumoniae, H influenzae, and N meningitidis during the first 2 years of the pandemic, but cases began to increase in some countries towards the end of 2021 as pandemic restrictions were lifted. These IRIS data provide a better understanding of microbial transmission, will inform vaccine development and implementation, and can contribute to health-care service planning and provision of policies. FUNDING: Wellcome Trust, NIHR Oxford Biomedical Research Centre, Spanish Ministry of Science and Innovation, Korea Disease Control and Prevention Agency, Torsten Söderberg Foundation, Stockholm County Council, Swedish Research Council, German Federal Ministry of Health, Robert Koch Institute, Pfizer, Merck, and the Greek National Public Health Organization
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