Complete genome sequence of Brucella abortus isolated from a human blood culture sample in Tanzania.

Brucella abortus causes infections in humans and livestock. Bacterial isolates are challenging to obtain, and very little is known about the genomic epidemiology of this species in Africa. Here, we report the complete genome sequence of a Brucella abortus isolate cultured from a febrile human in northern Tanzania.

Genetic and nongenetic drivers of platelet reactivity in healthy Tanzanian individuals.

BACKGROUND: Platelets play a key role in hemostasis, inflammation, and cardiovascular diseases. Platelet reactivity is highly variable between individuals. The drivers of this variability in populations from Sub-Saharan Africa remain largely unknown. OBJECTIVES: We aimed to investigate the nongenetic and genetic determinants of platelet reactivity in healthy adults living in a rapidly urbanizing area in Northern Tanzania. METHODS: Platelet activation and reactivity were measured by platelet P-selectin expression and the binding of fibrinogen in unstimulated blood and after ex vivo stimulation with adenosine diphosphate and PAR-1 and PAR-4 ligands. We then analyzed the associations of platelet parameters with host genetic and nongenetic factors, environmental factors, plasma inflammatory markers, and plasma metabolites. RESULTS: Only a few associations were found between platelet reactivity parameters and plasma inflammatory markers and nongenetic host and environmental factors. In contrast, untargeted plasma metabolomics revealed a large number of associations with food-derived metabolites, including phytochemicals that were previously reported to inhibit platelet reactivity. Genome-wide single-nucleotide polymorphism genotyping identified 2 novel single-nucleotide polymorphisms (rs903650 and rs4789332) that were associated with platelet reactivity at the genome-wide level (P < 5 × 10-8) as well as a number of variants in the PAR4 gene (F2RL3) that were associated with PAR4-induced reactivity. CONCLUSION: Our study uncovered factors that determine variation in platelet reactivity in a population in East Africa that is rapidly transitioning to an urban lifestyle, including the importance of genetic ancestry and the gradual abandoning of the traditional East African diet.

Nanopore sequencing technology for clinical diagnosis of infectious diseases where laboratory capacity is meager: A case report.

In resource-limited settings, patients are often first presented to clinical settings when seriously ill and access to proper clinical microbial diagnostics is often very limited or non-existing. On February 16th, 2022 we were on a field trip to test a completely field-deployable metagenomics sequencing set-up, that includes DNA purification, sequencing, and bioinformatics analyses using bioinformatics tools installed on a laptop for water samples, just outside Moshi, Tanzania. On our way to the test site, we were contacted by the nearby Machame hospital regarding a child seriously ill with diarrhea and not responding to treatment. Within the same day, we conducted an onsite metagenomics examination of a fecal sample from the child, and Campylobacter jejuni was identified as the causative agent. The treatment was subsequently changed, with almost immediate improvement, and the child was discharged on February 21st.

Ultrasensitive qPCR-Based Detection of Plasmodium falciparum in Pregnant Women Using Dried Blood or Whole Blood Pellet Samples Processed through Different DNA Extraction Methods.

Highly sensitive molecular techniques for the detection of low-level Plasmodium falciparum parasitemia are highly useful for various clinical and epidemiological studies. However, differences in how blood samples are preserved, the quantity of blood stored, as well as genomic DNA extraction methods used may compromise the potential usefulness of these methodologies. This study compared diagnostic sensitivity based on microscopy and malaria rapid diagnostic tests (mRDTs), with quantitative polymerase chain reaction (qPCR) P. falciparum positivity of dried blood spots (DBS) or whole blood pellets (WBP) from pregnant women using different DNA extraction protocols (Chelex-saponin or a commercial kit). Samples from 129 pregnant women were analyzed, of which 13 were P. falciparum positive by mRDT and 5 by microscopy. By using extraction kit on WBP and on DBS, qPCR positivity was 27 (20.9%) and 16 (12.4%), respectively, whereas Chelex extraction on DBS only resulted in 4 (3.1%) P. falciparum positive samples. Thus, extraction using commercial kits greatly improve the likelihood of detecting P. falciparum infections.