17 research outputs found
Detection of drug resistant Mycobacterium tuberculosis by high-throughput sequencing of DNA isolated from acid fast bacilli smears
BACKGROUND: Drug susceptibility testing for Mycobacterium tuberculosis (MTB) is difficult to perform in resource-limited settings where Acid Fast Bacilli (AFB) smears are commonly used for disease diagnosis and monitoring. We developed a simple method for extraction of MTB DNA from AFB smears for sequencing-based detection of mutations associated with resistance to all first and several second-line anti-tuberculosis drugs. METHODS: We isolated MTB DNA by boiling smear content in a Chelex solution, followed by column purification. We sequenced PCR-amplified segments of the rpoB, katG, embB, gyrA, gyrB, rpsL, and rrs genes, the inhA, eis, and pncA promoters and the entire pncA gene. RESULTS: We tested our assay on 1,208 clinically obtained AFB smears from Ghana (n = 379), Kenya (n = 517), Uganda (n = 262), and Zambia (n = 50). Coverage depth varied by target and slide smear grade, ranging from 300X to 12000X on average. Coverage of â„20X was obtained for all targets in 870 (72%) slides overall. Mono-resistance (5.9%), multi-drug resistance (1.8%), and poly-resistance (2.4%) mutation profiles were detected in 10% of slides overall, and in over 32% of retreatment and follow-up cases. CONCLUSION: This rapid AFB smear DNA-based method for determining drug resistance may be useful for the diagnosis and surveillance of drug-resistant tuberculosis
The bacterial skin microbiome in psoriatic arthritis, an unexplored link in pathogenesis: challenges and opportunities offered by recent technological advances.
The resident microbial community, harboured by humans in sites such as the skin and gastrointestinal tract, is enormous, representing a candidate environmental factor affecting susceptibility to complex diseases, where both genetic and environmental risk factors are important. The potential of microorganisms to influence the human immune system is considerable, given their ubiquity. The impact of the host-gene-microbe interaction on the maintenance of health and the development of disease has not yet been assessed robustly in chronic inflammatory conditions. PsA represents a model inflammatory disease to explore the role of the microbiome because skin involvement and overlap with IBD implicates both the skin and gastrointestinal tract as sources of microbial triggers for PsA. In parallel with genetic studies, characterization of the host microbiota may benefit our understanding of the microbial contribution to disease pathogenesis-knowledge that may eventually inform the development of novel therapeutics
Inflammatory arthritis in HIV positive patients: A practical guide
Background: Musculoskeletal manifestations of the human immunodeficiency virus (HIV) have been described since the outset of the global HIV epidemic. Articular syndromes that have been described in association with HIV include HIV-associated arthropathy, seronegative spondyloarthropathies (SPA) (reactive arthritis, psoriatic arthritis (PsA) and undifferentiated SPA), rheumatoid arthritis (RA) and painful articular syndrome.
Methods: We carried out a computer-assisted search of PubMed for the medical literature from January 1981 to January 2015 using the keywords HIV, acquired immune-deficiency syndrome, rheumatic manifestations, arthritis, spondyloarthropathy, anti-TNF and disease modifying antirheumatic drugs. Only English language literature was included and only studies involving adult human subjects were assessed.
Results: There are challenges in the management of inflammatory arthritis in patients who are HIV-positive, including difficulties in the assessment of disease activity and limited information on the safety of immunosuppressive drugs in these individuals.
Conclusions: This review focuses on the clinical characteristics of the inflammatory articular syndromes that have been described in association with HIV infection and discusses the therapeutic options for these patients
Pain amongst ethnic minority groups of South Asian origin in the United Kingdom: a review
Pain amongst ethnic minority groups of South Asian origin in the United Kingdom: a review
Nitazoxanide for persistent diarrhoea in Zambian acquired immune deficiency syndrome patients: a randomized-controlled trial
Background: Adults with acquired immune deficiency syndrome and persistent diarrhoea in Zambia have intestinal infection, predominantly protozoa.
Aim: To search for treatment which can be offered with minimal investigation, we carried out a doubleâblind, randomizedâcontrolled trial of nitazoxanide (a drug with a range of activity against parasites and bacteria).
Methods: Patients with diarrhoea of 1âmonth duration or longer were randomized to receive nitazoxanide (1000âmg twice daily) or placebo for 2âweeks. Endâpoints were clinical response, parasitological clearance and mortality.
Results: Two hundred and seven adults were randomized; 42 died during the study. The primary assessment of efficacy was made after 17âdays. Clinical response was observed in 56 (75%) of 75 patients receiving nitazoxanide and 45 (58%) of 77 patients receiving placebo (Pâ=â0.03). The rate of improvement was markedly higher in patients with CD4 counts under 50âcells/ÎŒL receiving nitazoxanide (Pâ=â0.007). The benefit was largely restricted to the period when the drug was being administered. No difference was seen in parasitological clearance between the two groups. Mortality was 19% by 4âweeks of followâup and did not differ with treatment allocation.
Conclusions: Nitazoxanide given orally for 14âdays was associated with clinical improvement in Zambian acquired immune deficiency syndrome patients with diarrhoea, especially those with very low CD4 counts
Genetic analysis of circulating and sequestered populations of Plasmodium falciparum in fatal pediatric malaria
Falciparum malaria is characterized by cytoadherence of host erythrocytes containing mature asexual-stage parasites and the consequent sequestration of these forms in tissue microvasculature. A postmortem study of pediatric malaria provided us with the opportunity to compare the genetic complexity of circulating and sequestered Plasmodium falciparum populations, in patients with fatal cerebral malaria ( CM) versus control subjects with incidental P. falciparum parasitemia who died of causes other than malaria. Parasite genotypes identified in peripheral blood collected at the time of admission to the hospital constituted a subset of those detected in the tissues at death. Despite a higher tissue burden of parasitized erythrocytes in patients with CM than in parasitemic control subjects, parasite populations in tissues from patients with CM were less genetically complex, and the genotypes were more homogeneously distributed throughout the body, than in patients with incidental infection. Our findings support the notion that CM is associated with the emergence of a small number of dominant genotypes in an infected individual