Unleashing the full power of LHCb to probe stealth new physics

In this paper, we describe the potential of the LHCb experiment to detect stealth physics. This refers to dynamics beyond the standard model that would elude searches that focus on energetic objects or precision measurements of known processes. Stealth signatures include long-lived particles and light resonances that are produced very rarely or together with overwhelming backgrounds. We will discuss why LHCb is equipped to discover this kind of physics at the Large Hadron Collider and provide examples of well-motivated theoretical models that can be probed with great detail at the experiment.

Mycobacterium abscessus subspecies abscessus infection associated with cosmetic surgical procedures: Cases series

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Mycobacterium abscessus is a drug-resistant nontuberculous mycobacterium (NTM).

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Cutaneous & subcutaneous NTM infections post-cosmetic surgery are poorly diagnosed.

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Initial surgical evaluation facilitates early suspicion of M. abscessus infection.

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Rapidly evolving infection & negative culture/antibiotic response are indicators.

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Amikacin, imipenem, & clarithromycin combination may treat M. abscessus infection.

Background

Mycobacterium abscessus is one of the most pathogenic and drug-resistant opportunistic microorganisms among the nontuberculous mycobacteria (NTM) involved in skin and soft tissue infections (SSTI) associated with cosmetic surgical procedures. However, NTM infection is often wrongly diagnosed initially causing prolonged suffering. Here is described the author’s experience working with patients who developed M. abscessus SSTI after cosmetic procedures.

Methods

Patients who developed NTM infection after undergoing cosmetic procedures, and who presented at the Hospital Metropolitano and Hospital Vozandes (Quito, Ecuador) between 2013–2016. A review of patient medical records was performed.

Results

Five patients with culture proven M. abscessus subspecies abscessus SSTI after cosmetic surgeries were identified. All patients were treated with aggressive surgical debridement and antibiotics.

Conclusions

A rapidly spreading wound infection presenting two or more weeks after a cosmetic procedure that fails to respond to standard antimicrobial therapy should raise suspicion for NTM infection. Samples for acid-fast bacilli smear, cultures, and PCR from infected tissue should be taken. Surgical drainage and debridement are recommended along with a long course of antibiotics. In the absence of clinical trials, a combination of amikacin, imipenem, and clarithromycin may be an adequate initial treatment for M. abscessus subspecies abscessus SSTI in immunocompetent patients.

Segniliparus rugosus from the sputum of a child with cystic fibrosis in Ecuador: challenges in bacterial identification

Using sequencing analyses of the 16S rRNA gene, we identified Segniliparus rugosus in an 8-year-old child with cystic fibrosis. We describe the difficulties we encountered in identifying this bacterium. To the best of our knowledge, this is the first reported case of S. rugosus in Ecuador.

Genetic diversity and drug resistance of Mycobacterium tuberculosis in Ecuador

BACKGROUND

The genetic diversity of Mycobacterium tuberculosis in Quito, Ecuador is not well known.

OBJECTIVE

To investigate mutations related to drug resistance and bacterial genotypes in M. tuberculosis strains in Ecuador.

DESIGN

This was a retrospective study of M. tuberculosis isolates from 104 patients. Isolates were phenotypically resistant to rifampicin (RMP) and/or isoniazid (INH). The genotype was determined using 24-locus mycobacterial interspersed repetitive units-variable-number tandem repeats (MIRU-VNTR).

RESULTS

Isolates showed mutations in the rpoB and katG genes, and the inhA promoter. In rpoB, we found 13 genetic alterations at codons 511, 513, 514, 515, 516, 526 and 531. Forty-six (44.2%) RMP-resistant isolates belonged to codon 531. In katG, there were nine genetic alterations at codons 296, 312, 314, 315, 322, 324 and 351. Fifty-three (51%) INH-resistant isolates belonged to codon 315. Five mutations not previously described were identified in katG: Thr324Ser, Thr314Ala, Ala312Pro, Trp351Stop and deleted G at 296 codon. The Latin American Mediterranean (LAM) (33.7%) and Ghana (30.8%) lineages presented most of the main mutations observed.

CONCLUSION

This is the first report from Ecuador; it describes five new mutations in katG and indicates that LAM is the most prevalent lineage.

Ready-to-eat street food: a potential source for dissemination of multidrug-resistant Escherichia coli epidemic clones in Quito, Ecuador

Ready-to-eat food contamination with ESBL-producing Escherichia coli is a growing health concern. Some of these strains also are epidemic clones and can cause community-associated infections that are difficult to treat. In this study, the occurrence of ESBL-producing E. coli contaminated ready-to-eat street food in Quito, Ecuador was evaluated. In total, 150 samples were collected randomly in the most crowded sites of the city. In all, 34 samples (34/150; 22·6%) were positive for total thermotolerant (44·5°C) coliforms resistant to cefotaxime. MALDI-TOF analysis identified that the E. coli was found in 20 food samples (20/34; 59%). ESBL gene bla_CTX-M-55 was identified in nine isolates, bla_CTX-M-15 in six isolates, bla_CTX-M-14 in two isolates, and one isolate each harboured bla_CTX-M-24 , bla_CTX-M-65 , bla_CTX-M-55 and bla_CTX-M-8 . Phylogenetic groups like A and B1 were the most common, followed by groups D and B2. MLST analysis identified 12 different sequence types (STs), the most common was ST162. Recognized epidemic clonal groups ST410, ST131 and ST744 were encountered. Ready-to-eat street food is a potential way of spreading ESBL-producing E. coli epidemic clones in Quito, Ecuador. SIGNIFICANCE AND IMPACT OF THE STUDY: This study identified ESBL-producing Escherichia coli epidemic clones: ST131, ST410 and ST744 in ready-to-eat street food samples. Street food is a possible way to spread harm multidrug-resistant (MDR) E. coli strains in the community. Studies to identify the contamination sources of this kind of food are needed to tackle MDR E. coli dissemination.

Long-lived particles at the energy frontier: the MATHUSLA physics case

We examine the theoretical motivations for long-lived particle (LLP) signals at the LHC in a comprehensive survey of standard model (SM) extensions. LLPs are a common prediction of a wide range of theories that address unsolved fundamental mysteries such as naturalness, dark matter, baryogenesis and neutrino masses, and represent a natural and generic possibility for physics beyond the SM (BSM). In most cases the LLP lifetime can be treated as a free parameter from the [Formula: see text]m scale up to the Big Bang Nucleosynthesis limit of [Formula: see text] m. Neutral LLPs with lifetimes above [Formula: see text]100 m are particularly difficult to probe, as the sensitivity of the LHC main detectors is limited by challenging backgrounds, triggers, and small acceptances. MATHUSLA is a proposal for a minimally instrumented, large-volume surface detector near ATLAS or CMS. It would search for neutral LLPs produced in HL-LHC collisions by reconstructing displaced vertices (DVs) in a low-background environment, extending the sensitivity of the main detectors by orders of magnitude in the long-lifetime regime. We study the LLP physics opportunities afforded by a MATHUSLA-like detector at the HL-LHC, assuming backgrounds can be rejected as expected. We develop a model-independent approach to describe the sensitivity of MATHUSLA to BSM LLP signals, and compare it to DV and missing energy searches at ATLAS or CMS. We then explore the BSM motivations for LLPs in considerable detail, presenting a large number of new sensitivity studies. While our discussion is especially oriented towards the long-lifetime regime at MATHUSLA, this survey underlines the importance of a varied LLP search program at the LHC in general. By synthesizing these results into a general discussion of the top-down and bottom-up motivations for LLP searches, it is our aim to demonstrate the exceptional strength and breadth of the physics case for the construction of the MATHUSLA detector.

EARLY-ESLI study: Long-term experience with eslicarbazepine acetate after first monotherapy failure

PURPOSE

Evaluate real-life experience with eslicarbazepine acetate (ESL) after first monotherapy failure in a large series of patients with focal epilepsy.

METHOD

Multicentre, retrospective, 1-year, observational study in patients older than 18 years, with focal epilepsy, who had failed first antiepileptic drug monotherapy and who received ESL. Data from clinical records were analysed at baseline, 3, 6 and 12 months to assess effectiveness and tolerability.

RESULTS

Eslicarbazepine acetate was initiated in 253 patients. The 1-year retention rate was 92.9%, and the final median dose of ESL was 800 mg. At 12 months, 62.3% of patients had been seizure free for 6 months; 37.3% had been seizure free for 1 year. During follow-up, 31.6% of the patients reported ESL-related adverse events (AEs), most commonly somnolence (8.7%) and dizziness (5.1%), and 3.6% discontinued due to AEs. Hyponatraemia was observed in seven patients (2.8%). After starting ESL, 137 patients (54.2%) withdrew the prior monotherapy and converted to ESL monotherapy; 75.9% were seizure free, 87.6% were responders, 4.4% worsened, and 23.4% reported ESL-related AEs.

CONCLUSION

Use of ESL after first monotherapy failure was associated with an optimal seizure control and tolerability profile. Over half of patients were converted to ESL monotherapy during follow-up.

Serious fungal infections in Ecuador

There is a dearth of data from Ecuador on the burden of life-threatening fungal disease entities; therefore, we estimated the burden of serious fungal infections in Ecuador based on the populations at risk and available epidemiological databases and publications. A full literature search was done to identify all epidemiology papers reporting fungal infection rates. WHO, ONU-AIDS, Index Mundi, Global Asthma Report, Globocan, and national data [Instituto Nacional de Estadística y Censos (INEC), Ministerio de Salud Pública (MSP), Sociedad de Lucha Contra el Cáncer (SOLCA), Instituto Nacional de Donación y Trasplante de Órganos, Tejidos y Células (INDOT)] were reviewed. When no data existed, risk populations were used to estimate frequencies of fungal infections, using previously described methodology by LIFE. Ecuador has a variety of climates from the cold of the Andes through temperate to humid hot weather at the coast and in the Amazon basin. Ecuador has a population of 15,223,680 people and an average life expectancy of 76 years. The median estimate of the human immunodeficiency virus (HIV)/acquired immune deficiency syndrome (AIDS) population at risk for fungal disease (<200 CD4 cell counts) is ∼10,000, with a rate of 11.1% (1100) of histoplasma, 7% (700) of cryptococcal meningitis, and 11% (1070) of Pneumocystis pneumonia. The burden of candidemia is 1037. Recurrent Candida vaginitis (≥4 episodes per year) affects 307,593 women aged 15-50 years. Chronic pulmonary aspergillosis probably affects ∼476 patients following tuberculosis (TB). Invasive aspergillosis is estimated to affect 748 patients (∼5.5/100,000). In addition, allergic bronchopulmonary aspergillosis (ABPA) in asthma and severe asthma with fungal sensitization (SAFS) were estimated to affect 26,642 and 45,013 people, respectively. Our estimates indicate that 433,856 (3%) of the population in Ecuador is affected by serious fungal infection.

Panniculitis caused by Mycobacterium monacense mimicking erythema induratum: a case in Ecuador

We report the first case of recently characterized species M. monacense associated with chronic nodular vasculitis, infecting a young woman. This case represents the first isolation of M. monacense from Ecuador. The isolate was identified by conventional and molecular techniques.

Automatized Patient-Specific Methodology for Numerical Determination of Biomechanical Corneal Response

This work presents a novel methodology for building a three-dimensional patient-specific eyeball model suitable for performing a fully automatic finite element (FE) analysis of the corneal biomechanics. The reconstruction algorithm fits and smooths the patient's corneal surfaces obtained in clinic with corneal topographers and creates an FE mesh for the simulation. The patient's corneal elevation and pachymetry data is kept where available, to account for all corneal geometric features (central corneal thickness-CCT and curvature). Subsequently, an iterative free-stress algorithm including a fiber's pull-back is applied to incorporate the pre-stress field to the model. A convergence analysis of the mesh and a sensitivity analysis of the parameters involved in the numerical response is also addressed to determine the most influential features of the FE model. As a final step, the methodology is applied on the simulation of a general non-commercial non-contact tonometry diagnostic test over a large set of 130 patients-53 healthy, 63 keratoconic (KTC) and 14 post-LASIK surgery eyes. Results show the influence of the CCT, intraocular pressure (IOP) and fibers (87%) on the numerical corneal displacement (U(Num)) the good agreement of the U(Num) with clinical results, and the importance of considering the corneal pre-stress in the FE analysis. The potential and flexibility of the methodology can help improve understanding of the eye biomechanics, to help to plan surgeries, or to interpret the results of new diagnosis tools (i.e., non-contact tonometers).

Characterization of the first report of Mycobacterium timonense infecting an HIV patient in an Ecuadorian hospital

Mycobacterium timonense is a non-tuberculous mycobacteria (NTM) described in southern France in 2009, and to our knowledge, not reported again as a human pathogen in indexed literature. The aim of this work was to characterize the first clinical isolate of M. timonense in Ecuador. Time of growth, biochemical tests, thin layer growth test, PCR-RFLP analysis of the hsp65 gene and MALDI-TOF spectra analysis were not able to identify the species. The species identification was achieved through sequencing of rrs, hsp65 and rpoB genes. The results highlight the necessity to set up a sequencing method to identify emerging NTM in Ecuadorian clinical facilities.

Toxic effects produced by microcystins from a natural cyanobacterial bloom and a Microcystis aeruginosa isolated strain on the fish cell lines RTG-2 and PLHC-1

Toxic cyanobacterial blooms are a worldwide problem, causing serious water pollution and public health hazard to humans and livestock. The intact cells as well as the toxins released after cellular lysis can be responsible for toxic effects in both animals and humans and are actually associated with fish kills. Two fish cell lines-PLHC-1 derived from a hepatocellular carcinoma of the topminnow Poeciliopsis lucida and RTG-2 fibroblast-like cells derived from the gonads of rainbow trout Oncorhynchus mykiss were exposed to several concentrations of extracts from a natural cyanobacterial bloom and a Microcystis aeruginosa-isolated strain. After 24 hours, morphologic and biochemical changes (total protein content, lactate dehydrogenase leakage, neutral red uptake, methathiazole tetrazolium salt metabolization, lysosomal function, and succinate dehydrogenase [SDH] activity) were investigated. The most sensitive end point for both cyanobacterial extracts in PLHC-1 cells was SDH activity, with similar EC(50) values (6 microM for the cyanobacterial bloom and 7 microM for the isolated strain). RTG-2 cells were less susceptible according to SDH activity, with their most sensitive end point lysosomal function with an EC(50) of 4 microM for the M. aeruginosa-isolated strain and 72 microM for the cyanobacterial bloom. The lysosomal function was stimulated at low concentrations, although SDH activity increased at high doses, indicating lysosomal and energetic alterations. Increased secretion vesicles, rounding effects, decreased cell numbers and size, hydropic degeneration, esteatosis, and apoptosis were observed in the morphologic study. Similar sensitivity to the M. aeruginosa-isolated strain was observed in both cell lines, whereas the cyanobacterial bloom was more toxic to the PLHC-1 cell line.

Evaluation of a rapid culture method for tuberculosis diagnosis: a Latin American multi-center study

SETTINGS

Tuberculosis (TB) diagnostic laboratories in Latin America.

OBJECTIVES

Evaluation of thin-layer agar (TLA) compared to Löwenstein-Jensen (LJ) culture for the diagnosis of TB.

DESIGN

Phase II prospective study in six laboratories. Samples included sputum and extra-pulmonary specimens from patients with a clinical diagnosis of TB. Respiratory samples were decontaminated using NaOH/ NALC; all samples were centrifuged, stained with Ziehl-Neelsen for acid-fast bacilli (AFB), cultured on LJ and TLA and identified according to recommended procedures. Sensitivity and likelihood ratios (LR), growth detection time and contamination rate were calculated for both media.

RESULTS

A total of 1118 clinical specimens were studied. Cultures detected Mycobacterium tuberculosis in all AFB-positive samples, whereas for AFB-negative specimens LJ detected 3.2% and TLA 4.4%. Sensitivity was 92.6% (95%CI 87.9-95.9) and 84.7% (95%CI 78.8-89.0) for TLA and LJ, respectively. Positive and negative LRs were similar. Contamination was 5.1% for TLA and 3.0% for LJ. Median time to detection of a positive culture was 11.5 days (95%CI 9.3-15.0) for TLA and 30.5 days (95%CI 26.9-39.0) for LJ (P < 0.0001).

CONCLUSION

Difference in the characteristics of the participating laboratories, the disease prevalence and the number and type of specimens processed did not affect the overall performance of TLA as compared to LJ, supporting the robustness of the method and its feasibility in different laboratory settings.

Adherence of dermatophyte microconidia and arthroconidia to human keratinocytes in vitro

The early interaction, adherence, between dermatophyte conidia and human keratinocytes has been studied in vitro. Two spore forms were used: microconidia and arthroconidia produced in vitro. The adherence of spores from three dermatophyte species, Trichophyton rubrum, T interdigitale, and T quinckeanum, was investigated using keratinocyte suspensions from different skin sites. Time-dependent adherence was demonstrated for all fungi studied with maximum adherence occurring between 3 and 4 h. There were no significant differences in adherence rates between the organisms studied. An order of affinity was established between keratinocytes from different sites and significant differences were demonstrated in adherence of microconidia to skin cells derived from sole versus knee. No differences in adherence rates were demonstrated in atopics versus patients with chronic dermatophytosis and normals. Adherence was inhibited, but not abolished, by subinhibitory concentrations of ketoconazole, itraconazole, and griseofulvin. The interaction between microconidia, arthroconidia, and keratinocytes was verified with scanning and transmission electron microscopy.