236 research outputs found
The Genome Sequence of 'Mycobacterium massiliense' Strain CIP 108297 Suggests the Independent Taxonomic Status of the Mycobacterium abscessus Complex at the Subspecies Level
Members of the Mycabacterium abscessus complex are rapidly growing mycobacteria that are emerging as human pathogens. The M. abscassus complex was previously composed of three species, namely M. abscessus sensu strict, 'M. massiliense', and M. bolletii', In 2011, 'M. massiliense' and 'M. bolletre' were united and reclassified as a single subspecies within M. abscessus: M. abscessus subsp. bolletii. However, the placement of 'M. massiliense' Within the boundary of M. abscessus subsp. balletii remains highly controversial with regard to clinical aspects. In this study, we revisited the taxonomic status of members of the M. abscessus complex based on comparative analysis of he whole-genome sequences of 53 strains, The genome sequence of the previous type strain of 'Mycobacterium massiliense' (CIP 108297) was determined using next-generation sequencing. The genome tree based on average nucleotide identity (AN I) values supported the differentiation of M. bolletii' and M. massiliense' at the subspecies level. The genome tree also clearly illustrated that 'M. bolletil' and 'M. massiliense' form a distinct phylogenetic clade within the radiation of the M. abscessus complex. The genomic distances observed in this study suggest that the current M. abscessus subsp. bolletii taxon should be divided into two subspecies, M. abscessus subsp. massiliense subsp. nov. and M. abscessus subsp. bolletii, to correspondingly accommodate the previously known 'M. assiliense' and 'M. bolletii' strains.
Pharmacokinetics and Dosing of Levofloxacin in Children Treated for Active or Latent Multidrug-resistant Tuberculosis, Federated States of Micronesia and Republic of the Marshall Islands
In the Federated States of Micronesia (FSM) and then the Republic of the Marshall Islands (RMI), levofloxacin pharmacokinetics (PK) were studied in children receiving directly observed once-daily regimens (10 mg/kg, age >5 years; 15–20 mg/kg, age ≤5 years) for either multidrug-resistant tuberculosis (MDR TB) disease or latent infection after MDR TB exposure, to inform future dosing strategies
Bovine Mammary Gland Biopsy Techniques
Bovine mammary gland biopsies allow researchers to collect tissue samples to study cell biology including gene expression, histological analysis, signaling pathways, and protein translation. This article describes two techniques for biopsy of the bovine mammary gland (MG). Three healthy Holstein dairy cows were the subjects. Before biopsies, cows were milked and subsequently restrained in a cattle chute. An analgesic (flunixin meglumine, 1.1 to 2.2 mg/kg of body weight) was administered via jugular intravenous [IV] injection 15-20 min prior to biopsy. For standing sedation, xylazine hydrochloride (0.01-0.05 mg/kg of body weight) was injected via the coccygeal vessels 5-10 min before the procedure. Once adequately sedated, the biopsy site was aseptically prepared and locally anaesthetized with 6 mL of 2% lidocaine hydrochloride via subcutaneous injection. Using aseptic technique, a 2 to 3 cm vertical incision was made using a number 10 scalpel. Core and needle biopsy tools were used. The core biopsy tool was attached to a cordless drill and inserted into the MG tissue through the incision using a clock-wise drill action. The needle biopsy tool was manually inserted into the incision site. Immediately after the procedure, an assistant applied pressure on the incision site for 20 to 25 min using a sterile towel to achieve hemostasis. Stainless steel surgical staples were used to oppose the skin incision. The staples were removed 10 days post-procedure. The main advantages of core and needle biopsies is that both approaches are minimally invasive procedures that can be safely performed in healthy cows. Milk yield following the biopsy was unaffected. These procedures require a short recovery time and result in fewer risks of complications. Specific limitations may include bleeding after the biopsy and infection on the biopsy site. Applications of these techniques include tissue collection for clinical diagnosis and research purposes, such as primary cell culture
US Cystic Fibrosis Foundation and European Cystic Fibrosis Society consensus recommendations for the management of non-tuberculous mycobacteria in individuals with cystic fibrosis
Non-tuberculous mycobacteria (NTM) are ubiquitous environmental organisms that can cause chronic pulmonary infection, particularly in individuals with preexisting inflammatory lung disease such as cystic fibrosis(CF). Pulmonary disease caused by NTM has emerged as a major threat to the health of individuals with CF but remains difficult to diagnose and problematic to treat. In response to this challenge, the US Cystic Fibrosis Foundation (CFF) and the European Cystic Fibrosis Society (ECFS) convened an expert panel of specialists to develop consensus recommendations for the screening, investigation, diagnosis and management of NTM pulmonary disease in individuals with CF. Nineteen experts were invited to participate in the recommendation development process. Population, Intervention, Comparison, Outcome (PICO) methodology and systematic literature reviews were employed to inform draft recommendations. An anonymous voting process was used by the committee to reach consensus. All committee members were asked to rate each statement on a scale of: 0, completely disagree, to 9, completely agree; with 80% or more of scores between 7 and 9 being considered ‘good’ agreement. Additionally, the committee solicited feedback from the CF communities in the USA and Europe and considered the feedback in the development of the final recommendation statements. Three rounds of voting were conducted to achieve 80% consensus for each recommendation statement. Through this process, we have generated a series of pragmatic, evidence-based recommendations for the screening, investigation, diagnosis and treatment of NTM infection in individuals with CF as an initial step in optimising management for this challenging condition
Multiple Cytokines Are Released When Blood from Patients with Tuberculosis Is Stimulated with Mycobacterium tuberculosis Antigens
Mycobacterium tuberculosis (Mtb) infection may cause overt disease or remain latent. Interferon gamma release assays (IGRAs) detect Mtb infection, both latent infection and infection manifesting as overt disease, by measuring whole-blood interferon gamma (IFN-γ) responses to Mtb antigens such as early secreted antigenic target-6 (ESAT-6), culture filtrate protein 10 (CFP-10), and TB7.7. Due to a lack of adequate diagnostic standards for confirming latent Mtb infection, IGRA sensitivity for detecting Mtb infection has been estimated using patients with culture-confirmed tuberculosis (CCTB) for whom recovery of Mtb confirms the infection. In this study, cytokines in addition to IFN-γ were assessed for potential to provide robust measures of Mtb infection.Cytokine responses to ESAT-6, CFP-10, TB7.7, or combinations of these Mtb antigens, for patients with CCTB were compared with responses for subjects at low risk for Mtb infection (controls). Three different multiplexed immunoassays were used to measure concentrations of 9 to 20 different cytokines. Responses were calculated by subtracting background cytokine concentrations from cytokine concentrations in plasma from blood stimulated with Mtb antigens.Two assays demonstrated that ESAT-6, CFP-10, ESAT-6+CFP-10, and ESAT-6+CFP-10+TB7.7 stimulated the release of significantly greater amounts of IFN-γ, IL-2, IL-8, MCP-1 and MIP-1β for CCTB patients than for controls. Responses to combination antigens were, or tended to be, greater than responses to individual antigens. A third assay, using whole blood stimulation with ESAT-6+CFP-10+TB7.7, revealed significantly greater IFN-γ, IL-2, IL-6, IL-8, IP-10, MCP-1, MIP-1β, and TNF-α responses among patients compared with controls. One CCTB patient with a falsely negative IFN-γ response had elevated responses with other cytokines.Multiple cytokines are released when whole blood from patients with CCTB is stimulated with Mtb antigens. Measurement of multiple cytokine responses may improve diagnostic sensitivity for Mtb infection compared with assessment of IFN-γ alone
Development of Drugs for Nontuberculous Mycobacterial Disease:Clinicians’ Interpretation of a US Food and Drug Administration Workshop
The US Food and Drug Administration convened a workshop to discuss clinical trial design challenges and considerations related to the treatment of nontuberculous mycobacterial pulmonary disease, to include topics such as clinical trial end points, duration, and populations. The clinicians participating in the meeting provide here their interpretation of the discussion, which included US Food and Drug Administration and industry representatives. The treatment of nontuberculous mycobacterial pulmonary disease typically includes multiple antibiotics for a prolonged period and can be difficult to tolerate; there is a great need for new treatment options. Most individuals have a microbiologic response to therapy, but data correlating decreasing bacillary load with patient-reported outcomes or measured functional improvement are lacking. Accordingly, trial designs for new therapeutic agents should incorporate both microbiologic and clinical outcome measures and select appropriate study candidates with capacity for measurable change of such outcome measures. The need for shorter study designs, early primary end points, and placebo control arms was highlighted during the workshop
Factors associated with mortality in patients with drug-susceptible pulmonary tuberculosis
<p>Abstract</p> <p>Background</p> <p>Tuberculosis is a leading cause of death worldwide, yet the determinants of death are not well understood. We sought to determine risk factors for mortality during treatment of drug-susceptible pulmonary tuberculosis under program settings.</p> <p>Methods</p> <p>Retrospective chart review of patients with drug-susceptible tuberculosis reported to the San Francisco Tuberculosis Control Program from 1990-2001.</p> <p>Results</p> <p>Of 565 patients meeting eligibility criteria, 37 (6.6%) died during the study period. Of 37 deaths, 12 (32.4%) had tuberculosis listed as a contributing factor. In multivariate analysis controlling for follow-up time, four characteristics were independently associated with mortality: HIV co-infection (HR = 2.57, p = 0.02), older age at tuberculosis diagnosis (HR = 1.52 per 10 years, p = 0.001); initial sputum smear positive for acid fast bacilli (HR = 3.07, p = 0.004); and experiencing an interruption in tuberculosis therapy (HR = 3.15, p = 0.002). The association between treatment interruption and risk of death was due to non-adherence during the intensive phase of treatment (HR = 3.20, p = 0.001). The median duration of treatment interruption did not differ significantly in either intensive or continuation phases between those who died and survived (23 versus 18 days, and 37 versus 29 days, respectively). No deaths were directly attributed to adverse drug reactions.</p> <p>Conclusions</p> <p>In addition to advanced age, HIV and characteristics of advanced tuberculosis, experiencing an interruption in anti-tuberculosis therapy, primarily due to non-adherence, was also independently associated with increased risk of death. Improving adherence early during treatment for tuberculosis may both improve tuberculosis outcomes as well as decrease mortality.</p
Treatment outcome definitions in nontuberculous mycobacterial pulmonary disease: an NTM-NET consensus statement
Nontuberculous mycobacterial pulmonary diseases (NTM-PD) are increasingly recognised as opportunistic infections of humans. These chronic pulmonary infections have two main presentations. The first is a fibro-cavitary disease, that occurs in patients with pre-existing pulmonary diseases, such as chronic obstructive pulmonary disease, bronchiectasis, previous tuberculosis or other structural lung disease. The second presentation is a nodular- bronchiectatic disease of primarily the lingula and middle lobe that tends to affect a middle- aged and elderly female population [1]. Treatment of NTM-PD requires long-term administration of complex multidrug therapies that are species-specific. Currently recommended regimens are supported by a very limited evidence base [2, 3]. The increasing incidence of NTM-PD has sparked increased interest in performing prospective randomised clinical trials [4]. One of the drawbacks of the existing case series and clinical trials is that they have applied different outcome measures [5]. This hampers meta-analyses, which are important in these still understudied infectious diseases. To enhance the quality and interpretability of the results of future trials and retrospective cohort studies, we aimed to formulate clear and broadly acceptable outcome definitions for NTM-PD treatment
Potential Public Health Impact of New Tuberculosis Vaccines
Widely deployed and highly effective pre- or postexposure vaccines would reduce the number of TB cases by only one third
Inflammatory monocytes damage the hippocampus during acute picornavirus infection of the brain
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