Context-dependent reduction in corticomuscular coupling for balance control in chronic stroke survivors.

Balance control is an important indicator of mobility and independence in activities of daily living. How the functional coupling between the cortex and the muscle for balance control is affected following stroke remains to be known. We investigated the changes in coupling between the cortex and leg muscles during a challenging balance task over multiple frequency bands in chronic stroke survivors. Fourteen participants with stroke and ten healthy controls performed a challenging balance task. They stood on a computerized support surface that was either fixed (low difficulty condition) or sway-referenced with varying gain (medium and high difficulty conditions). We computed corticomuscular coherence between electrodes placed over the sensorimotor area (electroencephalography) and leg muscles (electromyography) and assessed balance performance using clinical and laboratory-based tests. We found significantly lower delta frequency band coherence in stroke participants when compared with healthy controls under medium difficulty condition, but not during low and high difficulty conditions. These differences were found for most of the distal but not for proximal leg muscle groups. No differences were found at other frequency bands. Participants with stroke showed poor balance clinical scores when compared with healthy controls, but no differences were found for laboratory-based tests. The observation of effects at distal but not at proximal muscle groups suggests differences in the (re)organization of the descending connections across two muscle groups for balance control. We argue that the observed group difference in delta band coherence indicates balance context-dependent alteration in mechanisms for the detection of somatosensory modulation resulting from sway-referencing of the support surface for balance maintenance following stroke.

Progressive multifocal leukoencephalopathy and spectrum of predisposing conditions: a 20-year retrospective cohort study in a tertiary center in São Paulo, Brazil.

BACKGROUND: Epidemiological studies on predisposing conditions and outcomes of progressive multifocal leukoencephalopathy (PML) cases have been carried out exclusively in high-income countries. We aim to report and compare the main characteristics and outcomes of patients with PML and several underlying diseases in a referral center in a middle-income country. METHODS: We performed a retrospective cohort study of PML cases admitted to a tertiary care hospital in São Paulo, Brazil during 2000-2022. Demographic and PML-specific variables were recorded. One-year case-fatality rate and factors associated with death were identified using a multivariate Cox proportional hazards regression model. RESULTS: Ninety-nine patients with PML were included. HIV infection (84.8%) and malignancy (14.1%) were the most prevalent underlying conditions. Other predisposing diseases were autoimmune/inflammatory diseases (5.1%) and solid organ transplantation (1.0%). One (1.0%) patient had liver cirrhosis and another (1.0%) patient was previously healthy. Focal motor deficits (64.2%) and gait instability (55.1%) were the most common signs. The one-year case-fatality rate was 52.5% (95% CI 42.2-62.7). The one-year case-fatality rate (95% CI) in patients with or without malignancy (85.7%, 95% CI 57.2-98.2% and 47.1%, 95% CI 36.1-58.2%, respectively) were statistically different (P = 0.009). Crude and adjusted Cox regression models identified malignancy as independently associated with death (adjusted HR = 3.92, 95% CI 1.76-8.73, P = 0.001). CONCLUSIONS: HIV/AIDS was the predisposing condition in 84.8% of PML cases. The one-year case-fatality rate was 52.5% and having a malignancy was independently associated with death. This study reports emerging data on the epidemiology and outcome of PML in a middle-income country.

Association between neuroimaging and clinical outcomes in individuals with central nervous system cryptococcosis.

BACKGROUND: The radiological manifestations of central nervous system (CNS) cryptococcosis are diverse and often subtle. There is heterogeneity on how different neuroimaging patterns impact prognosis. This study aims to assess the association between the neuroimaging and clinical outcomes of CNS cryptococcosis. METHODS: All patients with CNS cryptococcosis between July 2017 and April 2023 who underwent brain magnetic resonance imaging (MRI) were included. The primary outcome was mortality during hospitalisation. Secondary outcomes were readmission, ventricular shunting, duration of hospitalisation and time to the first negative cerebrospinal fluid culture. We compared the outcomes for each of the five main radiological findings on the brain MRI scan. RESULTS: We included 46 proven CNS cryptococcosis cases. The two main comorbidity groups were HIV infection (20, 43%) and solid organ transplantation (10, 22%), respectively. Thirty-nine patients exhibited at least one radiological abnormality (85%), with the most common being meningeal enhancement (34, 74%). The mortality rates occurred at 11% (5/46) during hospitalisation. We found no significant disparities in mortality related to distinct radiological patterns. The presence of pseudocysts was significantly associated with the need for readmission (p = .027). The ventricular shunting was significantly associated with the presence of pseudocysts (p = .005) and hydrocephalus (p = .044). CONCLUSION: In this study, there is no association between brain MRI findings and mortality. Larger studies are needed to evaluate this important issue.

Effect of florfenicol on Piscirickettsia salmonis biofilm formed in materials used in salmonid nets, nylon and high-density polyethylene.

Piscirickettsiosis is the most prevalent bacterial disease affecting seawater salmon in Chilean salmon industry. Antibiotic therapy is the first alternative to counteract infections caused by Piscirickettsia salmonis. The presence of bacterial biofilms on materials commonly used in salmon farming may be critical for understanding the bacterial persistence in the environment. In the present study, the CDC Biofilm Reactor® was used to investigate the effect of sub- and over-MIC of florfenicol on both the pre-formed biofilm and the biofilm formation by P. salmonis under the antibiotic stimuli on Nylon and high-density polyethylene (HDPE) surfaces. This study demonstrated that FLO, at sub- and over-MIC doses, decreases biofilm-embedded live bacteria in the P. salmonis isolates evaluated. However, it was shown that in the P. salmonis Ps007 strain the presence of sub-MIC of FLO reduced its biofilm formation on HDPE surfaces; however, biofilm persists on Nylon surfaces. These results demonstrated that P. salmonis isolates behave differently against FLO and also, depending on the surface materials. Therefore, it remains a challenge to find an effective strategy to control the biofilm formation of P. salmonis, and certainly other marine pathogens that affect the sustainability of the Chilean salmon industry.

Brain-machine interface based on deep learning to control asynchronously a lower-limb robotic exoskeleton: a case-of-study.

BACKGROUND: This research focused on the development of a motor imagery (MI) based brain-machine interface (BMI) using deep learning algorithms to control a lower-limb robotic exoskeleton. The study aimed to overcome the limitations of traditional BMI approaches by leveraging the advantages of deep learning, such as automated feature extraction and transfer learning. The experimental protocol to evaluate the BMI was designed as asynchronous, allowing subjects to perform mental tasks at their own will. METHODS: A total of five healthy able-bodied subjects were enrolled in this study to participate in a series of experimental sessions. The brain signals from two of these sessions were used to develop a generic deep learning model through transfer learning. Subsequently, this model was fine-tuned during the remaining sessions and subjected to evaluation. Three distinct deep learning approaches were compared: one that did not undergo fine-tuning, another that fine-tuned all layers of the model, and a third one that fine-tuned only the last three layers. The evaluation phase involved the exclusive closed-loop control of the exoskeleton device by the participants' neural activity using the second deep learning approach for the decoding. RESULTS: The three deep learning approaches were assessed in comparison to an approach based on spatial features that was trained for each subject and experimental session, demonstrating their superior performance. Interestingly, the deep learning approach without fine-tuning achieved comparable performance to the features-based approach, indicating that a generic model trained on data from different individuals and previous sessions can yield similar efficacy. Among the three deep learning approaches compared, fine-tuning all layer weights demonstrated the highest performance. CONCLUSION: This research represents an initial stride toward future calibration-free methods. Despite the efforts to diminish calibration time by leveraging data from other subjects, complete elimination proved unattainable. The study's discoveries hold notable significance for advancing calibration-free approaches, offering the promise of minimizing the need for training trials. Furthermore, the experimental evaluation protocol employed in this study aimed to replicate real-life scenarios, granting participants a higher degree of autonomy in decision-making regarding actions such as walking or stopping gait.

Recurrent Chagas' disease meningomyelitis in an HIV-infected patient.

Chagas' disease reactivation leading to monophasic acute or subacute meningoencephalitis or space-occupying lesions is a well-described AIDS-defining condition in Latin America. We report a 59-year-old man native from the Northeast region of Brazil, with a second episode of subacute chagasic meningomyelitis. He had long-term multidrug-resistant HIV and had abandoned combined antiretroviral therapy (CD4+ lymphocyte count, 16 cells/mm³, and HIV viral load 169 403 copies/mL). He initially received benznidazole but switched to nifurtimox after developing myelotoxicity. He was discharged home having made a partial neurological improvement. Chagas' disease should be included in the differential diagnosis of meningomyelitis in people living with HIV/AIDS who are from endemic areas of this parasitic disease.

High prevalence of central nervous system cryptococcosis using a fingerprick whole-blood lateral flow assay in individuals with neurological symptoms and advanced HIV disease in a Brazilian emergency department.

Timely diagnosis is key in managing central nervous system (CNS) cryptococcosis in people living with HIV/AIDS (PLWHA). There are few data on implementing fingerprick whole-blood cryptococcal antigen (CrAg) lateral flow assay (LFA) as the first test for diagnosing CNS cryptococcosis. We evaluated the prevalence of CNS cryptococcosis and cryptococcal antigenemia using fingerprick whole-blood in a referral emergency department (ED) in São Paulo, Brazil. This was a prospective cohort study of consecutive adult PLWHA with advanced HIV disease and neurological symptoms. Fingerprick whole-blood CrAg LFA was performed at bedside. Seventy-four individuals were enrolled (median age = 40 years; males = 62%). Prevalence of CNS cryptococcosis was 17.6% (13/74); 95% confidence interval (CI), 9.4-30.0%, and prevalence of positive fingerprick whole-blood CrAg LFA was 25.7% (19/74); 95% CI, 15.5-40.1%. Among the six (8.1%) patients with positive fingerprick whole-blood CrAg LFA and negative CSF CrAg LFA, four (5.4%) had isolated asymptomatic cryptococcal antigenemia, one (1.3%) had symptomatic cryptococcal antigenemia, and one (1.3%) had cryptococcemia. Prevalence of CNS cryptococcosis and cryptococcal antigenemia using fingerprick whole-blood CrAg LFA was high. Point-of-care testing was important for diagnosing CNS cryptococcosis in an ED from a middle-income country.

Characteristics, mortality, associated variables with death, and therapeutic response among HIV-positive, solid organ transplant (SOT), and non-HIV-positive/non-transplant (NHNT) patients with cryptococcosis: First multicenter cohort study in Brazil.

Cryptococcosis is traditionally associated with immunocompromised patients but is increasingly being identified in those without the human immunodeficiency virus (HIV) or other immunocompetent individuals. We aim to describe the characteristics, mortality, and associated variables with death among hospitalized patients with cryptococcosis in Brazil. This is the first multicenter retrospective cohort study conducted in seven public tertiary Brazilian hospitals. A total of 384 patients were included; the median age was 39 years and 283 (73.7%) were men. In all, 304 HIV-positive were hosts (79.2%), 16 (4.2%) solid organ transplant (SOT), and 64 (16.7%) non-HIV-positive/non-transplant (NHNT). Central nervous system (CNS) cryptococcosis had a significantly higher number across disease categories, with 313 cases (81.5%). A total of 271 (70.6%) patients were discharged and 113 (29.4%) died during hospitalization. In-hospital mortality among HIV-positive, SOT, and NHNT was 30.3% (92/304), 12.5% (2/16), and 29.7% (19/64), respectively. Induction therapy with conventional amphotericin B (AMB) mainly in combination with fluconazole (234; 84.2%) was the most used. Only 80 (22.3%) patients received an AMB lipid formulation: liposomal (n = 35) and lipid complex (n = 45). Most patients who died belong to the CNS cryptococcosis category (83/113; 73.4%) when compared with the others (P = .017). Multivariate analysis showed that age and disseminated cryptococcosis had a higher risk of death (odds ratio [OR], 1.03; 95% confidence interval [CI], 1.01-1.05; P = .008 and OR, 1.84; 95% CI, 1.01-3.53; P = .048, respectively). Understanding the epidemiology of cryptococcosis in our settings will help to recognize the burden and causes of mortality and identify strategies to improve this scenario.

This multicenter cohort study included 384 hospitalized individuals with cryptococcosis in Brazil. Most individuals were men (74%), HIV-positive (79%), had central nervous system involvement (82%), and received conventional amphotericin plus fluconazole (84%). In-hospital mortality was high (29%).

Genomic features of Pseudomonas sp. RGM2144 correlates with increased survival of rainbow trout infected by Flavobacterium psychrophilum.

This study evaluated the probiotic potential of the biofilm formed by the strain Pseudomonas sp. RGM2144 on rainbow trout survival. When challenged with the fish pathogen Flavobacterium psychrophilum, Pseudomonas sp. RGM2144 increased rainbow trout survival to 92.7 ± 1.2% (control: 35.3 ± 9.5%, p < .0001). The draft genome of Pseudomonas sp. RGM2144 is 6.8 Mbp long, with a completeness 100% and a contamination of 0.4%. The genome contains 6122 protein-coding genes of which 3564 (~60%) have known functions. The genome and phylogeny indicate that Pseudomonas sp. RGM2144 is a new species in the Pseudomonas genus, with few virulence factors, plasmids, and genes associated with antimicrobial resistance, suggesting a non-pathogenic bacterium with protective potential. In addition, the genome encodes for 11 secondary metabolite biosynthetic gene clusters that could be involved in the inhibition of F. psychrophilum. We suggest that Pseudomonas sp. RGM2144 may be applied as a probiotic in salmonid fish farming.

Metrological Qualification of PD Analysers for Insulation Diagnosis of HVDC and HVAC Grids.

On-site partial discharge (PD) measurements have turned out to be a very efficient technique for determining the insulation condition in high-voltage electrical grids (AIS, cable systems, GIS, HVDC converters, etc.); however, there is not any standardised procedure for determining the performances of PD measuring systems. In on-line and on-site PD measurements, high-frequency current transformers (HFCTs) are commonly used as sensors as they allow for monitoring over long distances in high-voltage installations. To ensure the required performances, a metrological qualification of the PD analysers by applying an evaluation procedure is necessary. A novel evaluation procedure was established to specify the quantities to be measured (electrical charge and PD repetition rate) and to describe the evaluation tests considering the measured influence parameters: noise, charge amplitude, pulse width and time interval between consecutive pulses. This procedure was applied to different types of PD analysers used for off-line measurements, sporadic on-line measurements and continuous PD monitoring. The procedure was validated in a round-robin test involving two metrological institutes (RISE from Sweden and FFII from Spain) and three universities (TUDelft from the Netherlands, TAU from Finland and UPM from Spain). With this round-robin test, the effectiveness of the proposed qualification procedure for discriminating between efficient and inappropriate PD analysers was demonstrated. Furthermore, it was shown that the PD charge quantity can be properly determined for on-line measurements and continuous monitoring by integrating the pulse signals acquired with HFCT sensors. In this case, these sensors must have a flat frequency spectrum in the range between several tens of kHz and at least two tens of MHz, where the frequency pulse content is more significant. The proposed qualification procedure can be useful for improving the future versions of the technical specification TS IEC 62478 and the standard IEC 60270.

Design and Validation of a Low-Cost Mobile EEG-Based Brain-Computer Interface.

Objective: We designed and validated a wireless, low-cost, easy-to-use, mobile, dry-electrode headset for scalp electroencephalography (EEG) recordings for closed-loop brain-computer (BCI) interface and internet-of-things (IoT) applications. Approach: The EEG-based BCI headset was designed from commercial off-the-shelf (COTS) components using a multi-pronged approach that balanced interoperability, cost, portability, usability, form factor, reliability, and closed-loop operation. Main Results: The adjustable headset was designed to accommodate 90% of the population. A patent-pending self-positioning dry electrode bracket allowed for vertical self-positioning while parting the user's hair to ensure contact of the electrode with the scalp. In the current prototype, five EEG electrodes were incorporated in the electrode bracket spanning the sensorimotor cortices bilaterally, and three skin sensors were included to measure eye movement and blinks. An inertial measurement unit (IMU) provides monitoring of head movements. The EEG amplifier operates with 24-bit resolution up to 500 Hz sampling frequency and can communicate with other devices using 802.11 b/g/n WiFi. It has high signal-to-noise ratio (SNR) and common-mode rejection ratio (CMRR) (121 dB and 110 dB, respectively) and low input noise. In closed-loop BCI mode, the system can operate at 40 Hz, including real-time adaptive noise cancellation and 512 MB of processor memory. It supports LabVIEW as a backend coding language and JavaScript (JS), Cascading Style Sheets (CSS), and HyperText Markup Language (HTML) as front-end coding languages and includes training and optimization of support vector machine (SVM) neural classifiers. Extensive bench testing supports the technical specifications and human-subject pilot testing of a closed-loop BCI application to support upper-limb rehabilitation and provides proof-of-concept validation for the device's use at both the clinic and at home. Significance: The usability, interoperability, portability, reliability, and programmability of the proposed wireless closed-loop BCI system provides a low-cost solution for BCI and neurorehabilitation research and IoT applications.

Development and Implementation of an Aesthetic Surgery Fellowship After Residency: The Universidad La Salle/Hospital Angeles Experience.

BACKGROUND: Postgraduate training in plastic surgery is heterogeneous between countries, with exposure to aesthetic surgery being a reflection of this. Fellowships in Mexico have usually consisted of tutorial teaching, providing graduates with experience but a lack of formal structure. The aim of his work is to present a University-backed program focused on aesthetic surgery and propose the expansion of this kind of program. METHODS: A retrospective cross-sectional review of surgical cases was performed over a five-year period from 2015 to 2019. Data were obtained from the senior surgeon's practice charts. Information was recorded using a data sheet including patients' demographic characteristics, procedures performed and type of anesthesia applied. Descriptive analyses of patient demographic and clinical characteristics were performed. Continuous variables are expressed in central tendency measures, and categorical values are presented as percentages. RESULTS: 1282 procedures were performed on 885 patients, 797 females (90%) and 88 males (10%). Mean age was 44.6 ± 13.8 years. Case load consisted in 545 breast procedures (42.5%), 372 body contour surgeries (29.0%), 305 facial aesthetic procedures (23.8%) and 60 miscellaneous procedures (4%). The most common surgeries were breast augmentation (249, 19.4%), alloplastic breast reconstruction (165, 12.8%), blepharoplasty (163, 12.7%), liposuction (151, 11.7%), and abdominoplasty (107, 8.3%). CONCLUSIONS: A University backed program focused on aesthetic surgery is feasible and desirable in multiple national and international institutions. LEVEL OF EVIDENCE V: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Ivermectin for the Treatment of Coronavirus Disease 2019: A Systematic Review and Meta-analysis of Randomized Controlled Trials.

BACKGROUND: We systematically assessed benefits and harms of the use of ivermectin (IVM) in patients with coronavirus disease 2019 (COVID-19). METHODS: Published and preprint randomized controlled trials (RCTs) assessing the effects of IVM on adult patients with COVID-19 were searched until 22 March 2021 in 5 engines. Primary outcomes were all-cause mortality rate, length of hospital stay (LOS), and adverse events (AEs). Secondary outcomes included viral clearance and severe AEs (SAEs). The risk of bias (RoB) was evaluated using the Cochrane Risk of Bias 2.0 tool. Inverse variance random effect meta-analyses were performed, with quality of evidence (QoE) evaluated using GRADE methods. RESULTS: Ten RCTs (n = 1173) were included. The controls were the standard of care in 5 RCTs and placebo in 5. COVID-19 disease severity was mild in 8 RCTs, moderate in 1, and mild and moderate in 1. IVM did not reduce all-cause mortality rates compared with controls (relative risk [RR], 0.37 [95% confidence interval, .12-1.13]; very low QoE) or LOS compared with controls (mean difference, 0.72 days [95% confidence interval, -.86 to 2.29 days]; very low QoE). AEs, SAEs, and viral clearance were similar between IVM and control groups (low QoE for all outcomes). Subgroups by severity of COVID-19 or RoB were mostly consistent with main analyses; all-cause mortality rates in 3 RCTs at high RoB were reduced with IVM. CONCLUSIONS: Compared with the standard of care or placebo, IVM did not reduce all-cause mortality, LOS, or viral clearance in RCTs in patients with mostly mild COVID-19. IVM did not have an effect on AEs or SAEs and is not a viable option to treat patients with COVID-19.

Clinical outcomes of HIV-syphilis coinfection among patients with no neurological symptoms: a retrospective cohort study.

OBJECTIVE: Our objective was to describe and compare the occurrence of neurological outcomes and neurosyphilis in people living with HIV with incident syphilis and no neurological symptoms who underwent early screening for asymptomatic neurosyphilis (ANS) or regular clinical management without a lumbar puncture. METHODS: This was a retrospective cohort study in a single referral centre of Sao Paulo, Brazil. Patients with incident syphilis diagnosed between January 2000 and August 2016 and meeting the adapted criteria for ANS investigation suggested by Marra et al. (CD4+ T-cell counts ≤350 cells/mm³ and/or venereal disease research laboratory test results ≥1:16) were identified. Those with no neurological symptoms and immediately referred for lumbar puncture were categorized as group 1, and those not referred for cerebrospinal fluid collection were categorized as group 2. We compared the occurrence of neurological symptoms and neurosyphilis diagnoses between the groups using incidence rates and Kaplan-Meier curves. RESULTS: We included 425 participants with a median follow-up of 6 years. The incidence rate of neurological symptoms was 36.5/1000 person-years in group 1 and 40.6/1000 person-years in group 2 (incidence rate ratio [IRR] 0.90; 95% confidence interval [CI] 0.57-1.39; p = 0.62). The incidence rate of neurosyphilis was 15.0 cases/1000 person-years in group 1 and 6.7 cases/1000 person-years in group 2 (IRR 2.26; 95% CI 0.93-5.68; p = 0.05). CONCLUSIONS: We found no statistically significant differences between groups in the incidence rates of neurological symptoms and neurosyphilis. Our findings support the current guidelines, which suggest a less invasive approach regarding ANS investigation among people living with HIV with incident syphilis.

Targeting Several Biologically Reported Targets of Glioblastoma Multiforme by Assaying 2D and 3D Cultured Cells.

Glioblastoma multiforme (GBM) is account for 70% of all primary malignancies of the central nervous system. The median survival of human patients after treatment is around 15 months. There are several biological targets which have been reported that can be pursued using ligands with varied structures to treat this disease. In our group, we have developed several ligands that target a wide range of proteins involved in anticancer effects, such as histone deacetylase (HDACs), G protein-coupled estrogen receptor 1 (GPER), estrogen receptor-beta (ERß) and NADPH oxidase (NOX), that were screened on bidimensional (2D) and tridimensional (3D) GBM stem cells like (GSC). Our results show that some HDAC inhibitors show antiproliferative properties at 21-32 µM. These results suggest that in this 3D culture, HDACs could be the most relevant targets that are modulated to induce the antiproliferative effects that require in the future further experimental studies.

Early clinical and microbiological predictors of outcome in hospitalized patients with cryptococcal meningitis.

BACKGROUND: Cryptococcal meningitis causes high mortality in immunocompromised and immunocompetent patients. The objective of this study was to identify early predictors of clinical outcome, available at the first days of hospitalization, in patients with cryptococcal meningitis in a tertiary center in Brazil. METHODS: Ninety-six cases of cryptococcal meningitis with clinical, epidemiological and laboratory data, and identification and antifungal susceptibility of the strains were analyzed. Quantitative CSF yeast counts were performed by direct microscopic exam with a Fuchs-Rosenthal cell counting chamber using an institutional protocol. Univariable and multiple analyses using logistic regression were performed to identify predictors, available at the beginning of hospitalization, of in-hospital mortality. Moreover, we performed a secondary analysis for a composite outcome defined by hospital mortality and intensive care unit transfer. RESULTS: The species and the antifungal susceptibility were not associated with the outcomes evaluated. The variables significantly associated with the mortality were age (OR = 1.08, 95% CI 1.02-1.15), the cerebrospinal fluid (CSF) yeasts count (OR = 1.65, 95% CI 1.20-2.27), systemic arterial hypertension (OR = 22.63, 95% CI 1.64-312.91) and neurological impairment identified by computed tomography (OR = 41.73, 95% CI 3.10-561.65). At the secondary analysis, CSF yeast count was also associated with the composite outcome, in addition to the culture of Cryptococcus spp. from bloodstream and cerebral toxoplasmosis. The associations were consistent with survival models evaluated. CONCLUSIONS: Age and CSF yeast count were independently associated with in-hospital mortality of patients with cryptococcal meningitis but Cryptococcus species identification and antifungal susceptibility were not associated with the outcomes. Quantitative CSF yeast counts used in this study can be evaluated and implemented in other low and middle-income settings.

Piscirickettsia salmonis forms a biofilm on nylon surface using a CDC Biofilm Reactor.

Research into Piscirickettsia salmonis biofilms on materials commonly used in salmon farming is crucial for understanding its persistence and virulence. We used the CDC Biofilm Reactor to investigate P. salmonis (LF-89 and EM-90) biofilm formation on Nylon, Stainless steel (316L), Polycarbonate and High-Density Polyethylene (HDPE) surfaces. After 144 h of biofilm visualization by scanning confocal laser microscopy under batch growth conditions, Nylon coupons generated the greatest biofilm formation and coverage compared to Stainless steel (316L), Polycarbonate and HDPE. Additionally, P. salmonis biofilm formation on Nylon was significantly greater (p ≤ .01) than Stainless steel (316L), Polycarbonate and HDPE at 288 h. We used Nylon coupons to determine the kinetic parameters of the planktonic and biofilm phases of P. salmonis. The two strains had similar latencies in the planktonic phase; however, LF-89 maximum growth was 2.5 orders of magnitude higher (Log cell ml-1 ). Additionally, LF-89 had a specified growth rate (µmax) of 0.0177 ± 0.006 h-1 and a generation time of 39.2 h. This study contributes to a deeper understanding of the biofilm formation by P. salmonis and elucidates the impact of the biofilm on aquaculture systems.

Diagnostic accuracy of Xpert MTB/RIF for tuberculous meningitis: systematic review and meta-analysis.

OBJECTIVE: This systematic review evaluated the diagnostic accuracy of Xpert MTB/RIF to detect tuberculous meningitis (TBM). METHODS: PubMed and five other databases were systematically searched through March 2019. All studies evaluating diagnostic accuracy of Xpert MTB/RIF on cerebrospinal fluid (CSF) samples were included. Reference standards were definitive or definite plus probable TBM. The quality of studies was assessed by the QUADAS-2 tool. We performed bivariate random-effects meta-analysis and calculated summary diagnostic statistics. RESULTS: We identified 30 studies (n = 3972 participants), including 5 cohort studies and 25 cross-sectional studies. Reference standards were definite TB (n = 28 studies) or definite plus probable TBM (n = 6 studies). The pooled Xpert MTB/RIF sensitivity was 85% (95% CI, 70-93%), and specificity was 98% (95% CI, 97-99%) with a negative likelihood ratio of 0.15 (95% CI, 0.04-0.27) for definite TBM. For probable TBM cases, pooled sensitivity was 81% (95% CI, 66-90%), and specificity was 99% (95% CI, 97-99%). For both reference standard types, meta-analyses showed a C-statistic area under the curve of 0.98. The QUADAS-2 tool revealed low risk of bias as well as low concerns regarding applicability. Methodological heterogeneity was high among studies. CONCLUSIONS: Xpert MTB/RIF showed high accuracy for TBM diagnosis, but a negative Xpert MTB/RIF test does not rule out TBM. Repeat Xpert testing may be necessary. In clinical practice, Xpert MTB/RIF adds speed and sensitivity when compared to classic TBM diagnostic methods or previous commercial nucleic acid amplification techniques. More studies and better strategies for rapidly confirming a diagnosis of TBM in children are urgently needed.

OBJECTIF: Cette revue systématique a évalué la précision diagnostique de Xpert MTB/RIF pour détecter la méningite tuberculeuse (MTB). MÉTHODES: PubMed et cinq autres bases de données ont fait l'objet d'une recherche systématique jusqu'en mars 2019. Toutes les études évaluant la précision du diagnostic de Xpert MTB/RIF sur des échantillons de liquide céphalo-rachidien (LCR) ont été incluses. Les étalons de référence étaient des MTB définitives ou définitives et probables. La qualité des études a été évaluée par l'outil QUADAS-2. Nous avons effectué une méta-analyse des effets aléatoires bivariés et calculé des statistiques de résumés diagnostiques. RÉSULTATS: Nous avons identifié 30 études (n = 3.972 participants), dont 5 études de cohorte et 25 études transversales. Les étalons de référence étaient la TB définitive (n = 28 études) ou la MTB définitive et probable (n = 6 études). La sensibilité poolée Xpert MTB/RIF était de 85% (IC95%: 70-93%) et la spécificité était de 98% (IC95%: 97-99%) avec un rapport de vraisemblance négatif de 0,15 (IC95%: 0,04-0,27) pour la MTB définitive. Pour les cas probables de la MTB, la sensibilité poolée était de 81% (IC95%: 66-90%) et la spécificité était de 99% (IC95%: 97-99%). Pour les deux types d'étalons de référence, les méta-analyses ont montré une aire statistique C sous la courbe de 0,98. L'outil QUADAS-2 a révélé un faible risque de biais ainsi que de faibles préoccupations concernant l'applicabilité. L'hétérogénéité méthodologique était élevée parmi les études. CONCLUSIONS: Xpert MTB/RIF a montré une grande précision pour le diagnostic de la MTB, mais un test Xpert MTB/RIF négatif n'exclut pas la MTB. La répétition du tests Xpert peut être nécessaire. Dans la pratique clinique, Xpert MTB/RIF ajoute vitesse et sensibilité par rapport aux méthodes de diagnostic classiques de la MTB ou aux précédentes techniques d'amplification d'acide nucléique commerciales. Des études supplémentaires et de meilleures stratégies pour confirmer rapidement un diagnostic de MTB chez les enfants sont nécessaires d'urgence.

High prevalence of Cryptococcal antigenemia using a finger-prick lateral flow assay in individuals with advanced HIV disease in Santarém Municipality, Brazilian Amazon Basin.

There is scarce information about HIV-related cryptococcosis in the Brazilian Amazon basin where laboratory infrastructure is limited. The serum cryptococcal antigen (CrAg) lateral flow assay (LFA) has simplified diagnosis of cryptococcosis and is recommended for screening in advanced HIV disease. We evaluated the prevalence of cryptococcal antigenemia using finger-prick CrAg LFA in the Brazilian Amazon basin. We enrolled a prospective cohort of outpatients and hospitalized individuals with advanced HIV disease at two centers in Santarém Municipality, Northern Brazil. All individuals were > 18 years old with advanced HIV disease, regardless of antiretroviral therapy (ART) status and with no prior or current history of confirmed cryptococcal meningitis. We tested CrAg LFA on finger-prick whole blood using an exact volume transfer pipette. From August 2018 to October 2019, 104 individuals were enrolled (outpatients 62 [60%] and hospitalized 42 [40%]). Median age was 38 years (interquartile range [IQR] 30-46), and 84 (81%) were male. Sixty-five (63%) individuals were ART-naïve. Prevalence of finger-prick CrAg LFA-positive was 10.6%; 95% CI, 5.4 to 18.1%. Prevalence of finger-prick CrAg LFA-positive among individuals without neurological symptoms was 6.0%; 95% CI, 1.7-14.6%. The number needed to test to detect one CrAg-positive individual was 9.4 persons (95% CI, 5.5-18.5). Prevalence of cryptococcal antigenemia using finger-prick whole blood CrAg LFA was high. Point-of-care approach was important for the diagnosis and screening of cryptococcosis in resource-limited settings. Screening and preemptive therapy strategy should be urgently implemented in individuals with advanced HIV disease in the Brazilian Amazon basin.

This prospective cohort study was carried-out in the Brazilian Amazon basin. We used a cryptococcal rapid test in patients with AIDS. We included 104 participants, and 11 (10.6%) of them had positive results showing a high prevalence of cryptococcal antigenemia.

Combining urine antigen and blood polymerase chain reaction for the diagnosis of disseminated histoplasmosis in hospitalized patients with advanced HIV disease.

Disseminated histoplasmosis (DH) is endemic in Latin America and the Caribbean where diagnostic tools are restricted. We carried-out a 1-year prospective cohort study at a referral hospital in São Paulo, Brazil. Participants had > or =18 years old, were hospitalized due to any indication and had CD4+ < 200 cells/µl. A urine commercial monoclonal Histoplasma galactomannan enzyme-linked immunosorbent assay (IMMY, Norman, OK, USA) and 'in house' Histoplasma blood nested PCR were performed in all cases. Probable/proven DH cases were defined according to international guidelines. Conventional mycological methods were available in routine conditions to investigate suspected DH cases. Treatment of participants followed the institutional routine. One-hundred six participants were included. Median age (interquartile range [IQR]) was 39.5 years (30.0-47.3) and 80 individuals (75.5%) were males. Median (IQR) CD4 cell count was 26.5 (9.4-89.3) cells/mm3. DH was diagnosed in 8/106 patients (7.5%). Antigen assay and/or PCR were positive in 4.7% (5/106) of patients. The antigen assay and/or PCR identified 37.5% (3/8) of DH cases, which had not been diagnosed with conventional mycological methods, but had clinical manifestations compatible with HD. In conclusion, the use of Histoplasma urine antigen and Histoplasma blood PCR guided by CD4 status contributed to the diagnosis of DH in hospitalized individuals. These assays were complementary to conventional mycologic methods and are urgently needed in our setting. LAY SUMMARY: In this prospective cohort study carried-out in a referral center in São Paulo, Brazil, we found a high frequency of AIDS-related disseminated histoplasmosis (8/106, 7.5%). We used urine antigen test and blood PCR assay to improve the diagnosis of this opportunistic disease.