Lewis and AB0 blood group-phenotypes in periodontitis, cardiovascular disease, obesity and stroke

Abstract The AB0 blood group has been linked to ischaemic heart disease, stroke, and periodontal disease, while the Lewis blood group has been linked to ischaemic heart disease and obesity, all of which have been associated with periodontitis. AB0 or Lewis blood group phenotype may therefore constitute common hereditary components predisposing to these disorders. In this study, we investigated if blood group phenotype associated with periodontitis in a subpopulation consisting of 702 participants from a Danish cross-sectional cohort and, secondarily, attempted to confirm their association with hypertension, ischaemic heart disease, stroke, and obesity. No significant association between blood group phenotype and periodontitis was detected, nor were previously reported associations between blood group phenotype and hypertension, ischaemic heart disease, stroke, and obesity confirmed. This may, at least partly, be attributed to differences in study type, outcome definitions, cohort sizes, and population attributable factors. However, our results suggested a strong association between self-reported stroke and the Lewis (a−b−) phenotype (P = 0.0002, OR: 22.28; CI 95: 4.72–131.63)

Microbacterium luticocti sp. nov., isolated from sewage sludge compost

Strain SC-087BT, isolated from sewage sludge compost during a study of bacterial diversity in composts, was characterized. The isolate was a Gram-positive, short rod that was motile, catalase- and oxidase-negative and able to grow at 27–45 6C, pH 5.5–9.7 and in up to 10% NaCl. The peptidoglycan was of the B2b type, containing the characteristic amino acids ornithine, homoserine and hydroxyglutamic acid. The muramic acid residues of the peptidoglycan were partially glycolylated. The major cell-wall sugar was mannose; traces of xylose were also detected. The predominant fatty acids, comprising more than 70% of the total, were anteiso-C17 : 0 and anteiso-C15 : 0, the major respiratory quinone was menaquinone-12 (MK-12) and the G+C content of the genomic DNA was 72 mol%. Based on analysis of the 16S rRNA gene sequence, the closest phylogenetic neighbours of strain SC-087BT were members of the family Microbacteriaceae, showing sequence similarity values of around 96% with members of the species Microbacterium barkeri (96.0 %), Microbacterium gubbeenense (95.6 %) and Microbacterium indicum (95.7 %). The chemotaxonomic and phenotypic traits analysed supported the inclusion of this strain within the genus Microbacterium and the proposal of a novel species. The name Microbacterium luticocti sp. nov. is proposed and the type strain is SC-087BT (5DSM 19459T5CCUG 54537T)

Rapid screening for glucose-6-phosphate dehydrogenase deficiency and haemoglobin polymorphisms in Africa by a simple high-throughput SSOP-ELISA method

BACKGROUND: Mutations in the haemoglobin beta-globin (HbB) and glucose-6-phosphate dehydrogenase (G6PD) genes cause widespread human genetic disorders such as sickle cell diseases and G6PD deficiency. In sub-Saharan Africa, a few predominant polymorphic variants of each gene account for a majority of these deficiencies. Examining at a larger scale the clinical importance of these independent genetic disorders, their possible association with malaria pathogenesis and innate resistance, and their relevance for antimalarial drug treatment, would be easier if an accurate screening method with limited costs was available. METHODS: A simple and rapid technique was developed to detect the most prominent single nucleotide polymorphisms (SNPs) in the HbB and G6PD genes. The method is able to detect the different haemoglobin polymorphisms A, S, C and E, as well as G6PD polymorphisms B, A and A- based on PCR-amplification followed by a hybridization step using sequence-specific oligonucleotide probes (SSOPs) specific for the SNP variants and quantified by ELISA. RESULTS: The SSOP-ELISA method was found to be specific, and compared well to the commonly used PCR-RFLP technique. Identical results were obtained in 98% (haemoglobin) and 95% (G6PD) of the tested 90 field samples from a high-transmission area in Tanzania, which were used to validate the new technique. CONCLUSION: The simplicity and accuracy of the new methodology makes it suitable for application in settings where resources are limited. It would serve as a valuable tool for research purposes by monitoring genotype frequencies in relation to disease epidemiology

Variation in NOD2 Augments Th2- and Th17 Responses to Myelin Basic Protein in Multiple Sclerosis

Variations in the gene for the nucleotide-binding oligomerisation domain (NOD) 2 have been associated with Crohn's disease but not multiple sclerosis (MS). Here we investigate the effect of three polymorphisms in the NOD2 gene (rs5743277, rs2066842 and rs5743291) on cytokine production and CD4+ T cell proliferation elicited by human myelin basic protein (MBP) in blood mononuclear cell (MNC) cultures from 29 patients with MS. No polymorphism was observed at rs5743277. No associations with the rs2066842 polymorphism were found. Concerning rs5743291, none were homozygous for the minor allele. Seven of 29 (24%) patients were heterozygous, and five of these (71%) exhibited increased MBP-induced CD4+ T cell proliferation versus four of 22 (18%), who were homozygous for the major allele (p<0.04). Interleukin (IL)-5 was induced by MBP in MNC from the same five carriers versus two (9%) homozygotes (p<0.004); four carriers (57%) versus three non-carriers (14%) exhibited IL-17 responses to MBP (p<0.04). By contrast, we found no association between the polymorphisms investigated and interferon-gamma-, tumor necrosis factor-alpha-, IL-2, -4- or IL-10 responses to MBP. These results indicate that the rs5743291 polymorphism influences T helper (Th) cell 2- and Th17 cell responses in MNC from MS patients

Accuracy of Malaria Rapid Diagnostic Tests in Community Studies and their Impact on Treatment of Malaria in an Area with Declining Malaria Burden in North-Eastern Tanzania.

Despite some problems related to accuracy and applicability of malaria rapid diagnostic tests (RDTs), they are currently the best option in areas with limited laboratory services for improving case management through parasitological diagnosis and reducing over-treatment. This study was conducted in areas with declining malaria burden to assess; 1) the accuracy of RDTs when used at different community settings, 2) the impact of using RDTs on anti-malarial dispensing by community-owned resource persons (CORPs) and 3) adherence of CORPs to treatment guidelines by providing treatment based on RDT results. Data were obtained from: 1) a longitudinal study of passive case detection of fevers using CORPs in six villages in Korogwe; and 2) cross-sectional surveys (CSS) in six villages of Korogwe and Muheza districts, north-eastern, Tanzania. Performance of RDTs was compared with microscopy as a gold standard, and factors affecting their accuracy were explored using a multivariate logistic regression model. Overall sensitivity and specificity of RDTs in the longitudinal study (of 23,793 febrile cases; 18,154 with microscopy and RDTs results) were 88.6% and 88.2%, respectively. In the CSS, the sensitivity was significantly lower (63.4%; χ2=367.7, p<0.001), while the specificity was significantly higher (94.3%; χ2=143.1, p<0.001) when compared to the longitudinal study. As determinants of sensitivity of RDTs in both studies, parasite density of<200 asexual parasites/μl was significantly associated with high risk of false negative RDTs (OR≥16.60, p<0.001), while the risk of false negative test was significantly lower among cases with fever (axillary temperature ≥37.5 °C) (OR≤0.63, p≤0.027). The risk of false positive RDT (as a determinant of specificity) was significantly higher in cases with fever compared to afebrile cases (OR≥2.40, p<0.001). Using RDTs reduced anti-malarials dispensing from 98.9% to 32.1% in cases aged ≥5 years. Although RDTs had low sensitivity and specificity, which varied widely depending on fever and parasite density, using RDTs reduced over-treatment with anti-malarials significantly. Thus, with declining malaria prevalence, RDTs will potentially identify majority of febrile cases with parasites and lead to improved management of malaria and non-malaria fevers

Important pharmacogenetic information for drugs prescribed during the SARS-CoV-2 infection (COVID-19)

In December 2019, the severe acute respiratory syndrome virus-2 pandemic began, causing the coronavirus disease 2019. A vast variety of drugs is being used off-label as potential therapies. Many of the repurposed drugs have clinical pharmacogenetic guidelines available with therapeutic recommendations when prescribed as indicated on the drug label. The aim of this review is to provide a comprehensive summary of pharmacogenetic biomarkers available for these drugs, which may help to prescribe them more safelyM.N.-G. is co-financed by the European Social Fund and the Youth European Initiative; grant number PEJ-2018-TL/BMD-1108

Rapid increase of Plasmodium falciparum dhfr/dhps resistant haplotypes, after the adoption of sulphadoxine-pyrimethamine as first line treatment in 2002, in southern Mozambique

<p>Abstract</p> <p>Background</p> <p>In late 2002, the health authorities of Mozambique implemented sulphadoxine-pyrimethamine (SP)/amodiaquine (AQ) as first-line treatment against uncomplicated falciparum malaria. In 2004, this has been altered to SP/artesunate in line with WHO recommendations of using Artemisinin Combination Therapies (ACTs), despite the fact that all the neighbouring countries have abandoned SP-drug combinations due to high levels of SP drug resistance. In the study area, one year prior to the change to SP/AQ, SP alone was used to treat uncomplicated malaria cases. The study described here investigated the immediate impact of the change to SP on the frequency of SP and CQ resistance-related haplotypes in the <it>Plasmodium falciparum </it>genes <it>Pfdhfr, Pfdhps </it>and <it>Pfcrt </it>before and a year after the introduction of SP.</p> <p>Methods</p> <p>Samples were collected during two cross sectional surveys in early 2002 and 2003 involving 796 and 692 children one year or older and adults randomly selected living in Maciana, an area located in Manhiça district, Southern Mozambique. Out of these, 171 and 173 <it>P. falciparum </it>positive samples were randomly selected to measure the frequency of resistance- related haplotypes in <it>Pfdhfr, Pfdhps </it>and <it>Pfcrt </it>based on results obtained by nested PCR followed by sequence-specific oligonucleotide probe (SSOP)-ELISA.</p> <p>Results</p> <p>The frequency of the SP-resistance associated <it>Pfdhps </it>double mutant (SGEAA) haplotype increased significantly from 14% to 35% (P < 0.001), while the triple mutant <it>Pfdhfr </it>haplotype (CIRNI) remained high and only changed marginally from 46% to 53% (P = 0.405) after one year with SP as first-line treatment in the study area. Conversely, the combined <it>Pfdhfr/Pfdhps </it>quintuple mutant haplotype increased from 8% to 26% (P = 0.005). The frequency of the chloroquine resistance associated <it>Pfcrt</it>-CVIET haplotype was above 90% in both years.</p> <p>Conclusion</p> <p>These retrospective findings add to the general concern on the lifespan of the combination of SP/artesunate in Mozambique. The high frequency of quintuple <it>Pfdhfr</it>/<it>Pfdhps </it>haplotypes found here as early as 2002 most likely cause ideal conditions for the development of artesunate tolerance in the <it>P. falciparum </it>populations and may even endanger the sensitivity to the second-line drug, Coartem^®.</p

Dried blood spots as a source of anti-malarial antibodies for epidemiological studies

BACKGROUND: Blood spots collected onto filter paper are an established and convenient source of antibodies for serological diagnosis and epidemiological surveys. Although recommendations for the storage and analysis of small molecule analytes in blood spots exist, there are no published systematic studies of the stability of antibodies under different storage conditions. METHODS: Blood spots, on filter paper or glass fibre mats and containing malaria-endemic plasma, were desiccated and stored at various temperatures for different times. Eluates of these spots were assayed for antibodies against two Plasmodium falciparum antigens, MSP-119 and MSP2, and calculated titres used to fit an exponential (first order kinetic) decay model. The first order rate constants (k) for each spot storage temperature were used to fit an Arrhenius equation, in order to estimate the thermal and temporal stability of antibodies in dried blood spots. The utility of blood spots for serological assays was confirmed by comparing antibodies eluted from blood spots with the equivalent plasma values in a series of samples from North Eastern Tanzania and by using blood spot-derived antibodies to estimate malaria transmission intensity in this site and for two localities in Uganda. RESULTS: Antibodies in spots on filter paper and glass fibre paper had similar stabilities but blood was more easily absorbed onto filter papers than glass fibre, spots were more regular and spot size was more closely correlated with blood volume for filter paper spots. Desiccated spots could be stored at or below 4 degrees C for extended periods, but were stable for only very limited periods at ambient temperature. When desiccated, recoveries of antibodies that are predominantly of IgG1 or IgG3 subclasses were similar. Recoveries of antibodies from paired samples of serum and of blood spots from Tanzania which had been suitably stored showed similar recoveries of antibodies, but spots which had been stored for extended periods at ambient humidity and temperature showed severe loss of recoveries. Estimates of malaria transmission intensity obtained from serum and from blood spots were similar, and values obtained using blood spots agreed well with entomologically determined values. CONCLUSION: This study has demonstrated the suitability of filter paper blood spots paper for collection of serum antibodies, and provided clear guidelines for the treatment and storage of filter papers which emphasize the importance of desiccation and minimisation of time spent at ambient temperatures. A recommended protocol for collecting, storing and assaying blood spots is provided

Potential impact of host immunity on malaria treatment outcome in Tanzanian children infected with Plasmodium falciparum

<p>Abstract</p> <p>Background</p> <p>In malaria endemic areas children may recover from malaria after chemotherapy in spite of harbouring genotypically drug-resistant <it>Plasmodium falciparum</it>. This phenomenon suggests that there is a synergy between drug treatment and acquired immunity. This hypothesis was examined in an area of moderately intense transmission of <it>P. falciparum </it>in Tanzania during a drug trail with sulphadoxine-pyrimethamine (SP) or amodiaquine (AQ).</p> <p>Methods</p> <p>One hundred children with uncomplicated malaria were treated with either SP or AQ and followed for 28 days. Mutations in parasite genes related to SP and AQ-resistance as well as human sickle cell trait and alpha-thalassaemia were determined using PCR and sequence-specific oligonucleotide probes and enzyme-linked immunosorbent assay (SSOP-ELISA), and IgG antibody responses to a panel of <it>P. falciparum </it>antigens were assessed and related to treatment outcome.</p> <p>Results</p> <p>Parasitological or clinical treatment failure (TF) was observed in 68% and 38% of children receiving SP or AQ, respectively. In those with adequate clinical and parasitological response (ACPR) compared to children with TF, and for both treatment regimens, prevalence and levels of anti-Glutamate-rich Protein (GLURP)-specific IgG antibodies were significantly higher (P < 0.001), while prevalence of parasite haplotypes associated with SP and AQ resistance was lower (P = 0.02 and P = 0.07, respectively). Interestingly, anti-GLURP-IgG antibodies were more strongly associated with treatment outcome than parasite resistant haplotypes, while the IgG responses to none of the other 11 malaria antigens were not significantly associated with ACPR.</p> <p>Conclusion</p> <p>These findings suggest that GLURP-specific IgG antibodies in this setting contribute to clearance of drug-resistant infections and support the hypothesis that acquired immunity enhances the clinical efficacy of drug therapy. The results should be confirmed in larger scale with greater sample size and with variation in transmission intensity.</p