Resolving a clinical tuberculosis outbreak using palaeogenomic genome reconstruction methodologies.

This study describes the analysis of DNA from heat-killed (boilate) isolates of Mycobacterium tuberculosis from two UK outbreaks where DNA was of sub-optimal quality for the standard methodologies routinely used in microbial genomics. An Illumina library construction method developed for sequencing ancient DNA was successfully used to obtain whole genome sequences, allowing analysis of the outbreak by gene-by-gene MLST, SNP mapping and phylogenetic analysis. All cases were spoligotyped to the same Haarlem H1 sub-lineage. This is the first described application of ancient DNA library construction protocols to allow whole genome sequencing of a clinical tuberculosis outbreak. Using this method it is possible to obtain epidemiologically meaningful data even when DNA is of insufficient quality for standard methods.

Emergence and spread of a human-transmissible multidrug-resistant nontuberculous mycobacterium.

Lung infections with Mycobacterium abscessus, a species of multidrug-resistant nontuberculous mycobacteria, are emerging as an important global threat to individuals with cystic fibrosis (CF), in whom M. abscessus accelerates inflammatory lung damage, leading to increased morbidity and mortality. Previously, M. abscessus was thought to be independently acquired by susceptible individuals from the environment. However, using whole-genome analysis of a global collection of clinical isolates, we show that the majority of M. abscessus infections are acquired through transmission, potentially via fomites and aerosols, of recently emerged dominant circulating clones that have spread globally. We demonstrate that these clones are associated with worse clinical outcomes, show increased virulence in cell-based and mouse infection models, and thus represent an urgent international infection challenge.

Potential for use of the Seegene Anyplex MTB/NTM real-time detection assay in a regional reference laboratory.

Requests for direct molecular diagnosis of mycobacterial disease are increasingly warranted. The Anyplex MTB/NTM assay demonstrates sensitivities, specificities, and positive and negative predictive values of 1.00, 0.96, 0.93, and 1.00 for Mycobacterium tuberculosis complex (MTBC) and 1.00, 0.97, 0.75, and 1.00 for nontuberculous mycobacteria (NTM) detection, respectively, making it a suitable screening test for mycobacterial detection.

Investigating transmission of Mycobacterium bovis in the United Kingdom in 2005 to 2008.

Due to an increase in bovine tuberculosis in cattle in the United Kingdom, we investigated the characteristics of Mycobacterium bovis infection in humans and assessed whether extensive transmission of M. bovis between humans has occurred. A cross-sectional study linking demographic, clinical, and DNA fingerprinting (using 15-locus mycobacterial interspersed repetitive-unit-variable-number tandem-repeat [MIRU-VNTR] typing) data on cases reported between 2005 and 2008 was undertaken. A total of 129 cases of M. bovis infection in humans were reported over the period, with a decrease in annual incidence from 0.065 to 0.047 cases per 100,000 persons. Most patients were born pre-1960, before widespread pasteurization was introduced (73%), were of white ethnicity (83%), and were born in the United Kingdom (76%). A total of 102 patients (79%) had MIRU-VNTR typing data. A total of 31 of 69 complete MIRU-VNTR profiles formed eight distinct clusters. The overall clustering proportion determined using the n - 1 method was 33%. The largest cluster, comprising 12 cases, was indistinguishable from a previously reported West Midlands outbreak strain cluster and included those cases. This cluster was heterogeneous, having characteristics supporting recent zoonotic and human-to-human transmission as well as reactivation of latent disease. Seven other, smaller clusters identified had demographics supporting recrudescence rather than recent infection. A total of 33 patients had incomplete MIRU-VNTR profiles, of which 11 may have yielded 2 to 6 further small clusters if typed to completion. The incidence of M. bovis in humans in the United Kingdom remains low, and the epidemiology is predominantly that of reactivated disease.

Unmet needs in managing hypertension: potential role of direct renin inhibition.

Hypertension is the most prevalent and important risk factor for cardiovascular and renal disease worldwide. Despite the large armamentarium of available blood pressure-lowering agents, the need remains for safer and more effective antihypertensive treatment. Based on current target levels of < 140/90 mm Hg, only one-third of hypertensive Americans have achieved goal blood pressure. Several strategies can help address these challenges, including increasing public awareness, and improving physician awareness of evidence-based therapeutic guidelines. There also remains a need for new therapeutic options. This review examines new developments among those agents having inhibitory activity on the renin-angiotensin-aldosterone system (RAAS). All currently available RAAS blockers cause a reactive increase in plasma renin concentration. However, the direct renin inhibitors are the only class that diminishes plasma renin activity, an effect that may provide additional cardiovascular and/or renoprotective benefit. Aliskiren is the first clinically available direct renin inhibitor that has been shown to be effective and well tolerated both as monotherapy and in combination with other established agents in hypertensive patients. Randomized clinical trials are underway to explore the extent to which direct renin inhibition provides additive protection against cardiovascular and renal disease events.

Antimicrobial prescribing patterns for respiratory diseases including tuberculosis in Russia: a possible role in drug resistance?

BACKGROUND: Inappropriate antibiotic prescribing exposes patients to the risk of side effects and encourages the development of drug resistance across antimicrobial groups used for respiratory infections including tuberculosis (TB). AIM: Determine among Russian general practitioners and specialists: (1) sources of antimicrobial prescribing information; (2) patterns of antimicrobial prescribing for common respiratory diseases and differences between primary and specialist physicians; (3) whether drug resistance in TB might be linked to over-prescribing of anti-TB drugs for respiratory conditions. METHODS: Point-prevalence cross-sectional survey involving all 28 primary care, general medicine and TB treatment institutions in Samara City, Russian Federation. In this two-stage study, a questionnaire was used to examine doctors' antimicrobial (including TB drugs) prescribing habits, sources of prescribing information, management of respiratory infections and a case scenario ('common cold'). This was followed by a case note review of actual prescribing for consecutive patients with respiratory diseases at three institutions. RESULTS: Initial questionnaires were completed by 81.3% (425/523) of physicians with 78.4% working in primary care. Most doctors used standard textbooks to guide their antimicrobial practice but 80% made extensive use of pharmaceutical company information. A minority of 1.7% would have inappropriately prescribed antibiotics for the case and 0.8-1.8% of respondents would have definitely prescribed TB drugs for non-TB conditions. Of the 495 respiratory cases, 25% of doctors prescribed an antibiotic for a simple upper respiratory tract infection and of 8 patients with a clinical diagnosis of TB, 4 received rifampicin monotherapy alone. Ciprofloxacin was widely but inappropriately used. CONCLUSION: Doctors rely on information provided by pharmaceutical companies; there was inappropriate antibiotic prescribing.

Rifampin- and multidrug-resistant tuberculosis in Russian civilians and prison inmates: dominance of the beijing strain family.

Consecutive patient cultures (140) of Mycobacteriium tuberculosis were collected from five Russian civilian and prison tuberculosis laboratories and analyzed for rifampin (rpoB) and isoniazid resistance (inhA, katG, ahpC); transmission of Beijing family isolates; and the importance of prison and previous therapy in drug resistance. Rifampin, isoniazid, and multidrug resistance occurred in 58.2%, 51.6%, and 44.7% of cultures, respectively; 80% of prison cultures were rifampin resistant. Spoligotyping and variable number tandem repeat (VNTR) fingerprinting divided the isolates into 43 groups. Spoligotyping demonstrated that a high proportion (68.1%) of patients were infected with Beijing family strains and that most (69.1%) were rifampin resistant; the highest proportion (81.6%) occurred in prison. One VNTR subgroup (42435) comprised 68 (72.3%) of the Beijing isolates with a small number of IS6110 types; 50 (73.5%) were rifampin resistant. Rifampin-resistant Beijing isolates are dominant within the patient population, especially among prisoners, and threaten treatment programs.

Effects of omapatrilat on the renin-angiotensin system in salt-sensitive hypertension.

The contribution of angiotensin-(1-7) [Ang-(1-7)] to the antihypertensive actions of omapatrilat, a novel vasopeptidase inhibitor, was evaluated in 22 salt-sensitive, low renin, hypertensive subjects as a substudy of a multicenter randomized, double-blind, parallel study of 4 weeks duration. A total of 25 other subjects received lisinopril as the active control. Omapatrilat (40 mg) produced sustained control of blood pressure (BP) (as assessed by 24-h ambulatory BP measurements) that was significantly greater than that produced by 20 mg daily of lisinopril. The antihypertensive response to either drug was accompanied by similar sustained inhibition of angiotensin converting enzyme activity. Plasma levels of angiotensin I (Ang I), angiotensin II (Ang II) and Ang-(1-7) were not altered by treatment with either omapatrilat or lisinopril, even though both regimens produced a modest rise in plasma renin activity. In contrast, urinary excretion rates of Ang I and Ang-(1-7) but not Ang II increased significantly throughout the dosing period of subjects who were given omapatrilat, whereas the smaller antihypertensive response produced by lisinopril had a smaller and transient effect on increasing urinary excretion rates of Ang-(1-7). Omapatrilat, being a single molecule inhibiting neutral endopeptidase and converting enzyme simultaneously, controlled salt-sensitive hypertension by a mechanism that was associated with sustained increases in urinary Ang-(1-7) excretion. We suggest that Ang-(1-7) may be a component of the mechanisms by which omapatrilat induces an antihypertensive response in salt sensitive hypertension.