Time-dependent impact of a high-fat diet on the intestinal barrier of male mice.

BACKGROUND: Excessive saturated fat intake compromises the integrity of the intestinal mucosa, leading to low-grade inflammation, impaired mucosal integrity, and increased intestinal permeability, resulting in the migration of lipopolysaccharide (LPS) to other tissues. AIM: To evaluate the chronic effects (at 10 and 16 wk) of a high-fat diet (HFD) (with 50% energy as fat) on the phylogenetic gut microbiota distribution and intestinal barrier structure and protection in C57BL/6 mice. METHODS: Forty adult male mice were divided into four nutritional groups, where the letters refer to the type of diet (control and HFD or HF) and the numbers refer to the period (in weeks) of diet administration: Control diet for 10 wk, HFD for 10 wk, control diet for 16 wk, and HFD for 16 wk. After sacrifice, biochemical, molecular, and stereological analyses were performed. RESULTS: The HF groups were overweight, had gut dysbiosis, had a progressive decrease in occludin immunostaining, and had increased LPS concentrations. Dietary progression reduced the number of goblet cells per large intestine area and Mucin2 expression in the HF16 group, consistent with a completely disarranged intestinal ultrastructure after 16 wk of HFD intake. CONCLUSION: Chronic HFD intake causes overweight, gut dysbiosis, and morphological and functional alterations of the intestinal barrier after 10 or 16 wk. Time-dependent reductions in goblet cell numerical density and mucus production have emerged as targets for countering obesity-driven intestinal damage.

Social sham chewing in sows?

In this short communication, we describe chewing behaviour in sows with no apparent edible substrate in their mouth as a potential social behaviour. Chewing in sows during interaction with unfamiliar sows was unexpectedly observed in a study assessing social abilities and damaging behaviours in group-housed dry sows. Such chewing was observed frequently and performed by almost all sows. To our knowledge, this behaviour has not been described previously in a social context in pigs, but rather as an oral stereotypic behaviour related to chronic hunger. We describe the behaviour in its social context and speculate on reasons for its occurrence in that context.

Pyrohydrolysis as a sample preparation method for the subsequent halogen determination: A review.

The use of pyrohydrolysis as a sample preparation method for further halogen determination is extensively discussed in this review, covering studies published in the last 30 years. This method is compatible with both organic (such as cellulose, fossil fuels, carbon nanotubes, and graphite) and inorganic (such as rocks, silicates, alumina, and nuclear fuels) matrices. It has also been used for samples with different organic matter content, such as coal, mineral supplements, and soil. Sample masses vary greatly and are dependent on organic matter content in the samples, ranging from 50 mg to up to 500 mg for organic samples, and up to 4 g to inorganic samples. Different additives, such as V2O5 and cellulose, or flame retardants, such as silica, could also be used to improve analyte recovery using pyrohydrolysis. Dilute alkaline solutions or even water have been used as absorbing solutions, with mainly NaOH, NH4OH, and mixtures of NaHCO3 and Na2CO3 being applied. Furthermore, pyrohydrolysis is compatible with detection techniques such as ion chromatography, inductively coupled plasma mass spectrometry, ion selective electrode, inductively coupled plasma optical emission spectrometry, energy-dispersive X-ray fluorescence spectrometry, spectrophotometry, and isotope ratio mass spectrometry. Other advantages usually related to this method are the low residual carbon concentration of digests and the low residue generation. A critical comparison with alkaline extraction, alkaline fusion, Schöniger oxygen flask combustion, combustion bomb and microwave-induced combustion is also provided.

Length of stay in the clinical wards in a hospital after introducing a multiprofessional discharge team: An effectiveness improvement report.

INTRODUCTION: Emergency overcrowding is a problem in hospitals worldwide. The expansion of wards has limitations. Hospital administrative leaders are constantly looking for opportunities to improve the efficiency of resource use. METHODS: This is a care improvement study with a quasi-experimental design. We created a hospital discharge team (HDT) to solve the issues of prolonged hospital stays. The main interventions were active search and resolution of prolongation of stay and multi-disciplinary huddles. We developed strategies with different hospital units to expedite the processing of patients near discharge. Length of stay (LOS), morning hospital discharges, readmission rates, and bed usage were compared before (2018) and after (2019) HDT implementation. RESULTS: There was a reduction in the mean LOS of 1.8 days (95% confidence interval [CI] -0.9 to -2.6; p < .001). The rate of hospital discharges before noon increased by 7.0% (95% CI 4%-11%; p < .001). The readmission rate was similar between 2018 and 2019 (+0.7%; 95% CI -0.1% to 1.9%; p = .358). We observed higher bed turnover, with 0.5 more hospitalizations per bed per month (95% CI 0.1-0.7; p = .01; mean of 3.7 ± 0.3 in 2018 and 4.1 ± 0.3 in 2019). CONCLUSION: HDT brought benefits to our hospital, reducing the length of stay and increasing bed turnover. However, there is a need for a team focused on the project and support from managers to overcome resistance and integrate units until they are fully operational.

PPARα/γ synergism activates UCP1-dependent and -independent thermogenesis and improves mitochondrial dynamics in the beige adipocytes of high-fat fed mice.

OBJECTIVE: The aim of this study was to investigate the role of peroxisome proliferator-activated receptor (PPAR) activation (single PPARα or PPARγ, and dual PPARα/γ) on UCP1-dependent and -independent thermogenic pathways and mitochondrial metabolism in the subcutaneous white adipose tissue of mice fed a high-fat diet. METHODS: Male C57BL/6 mice received either a control diet (10% lipids) or a high-fat diet (HF; 50% lipids) for 12 wk. The HF group was divided to receive the treatments for 4 wk: HFγ (pioglitazone, 10 mg/kg), HFα (WY-14643, 3.5 mg/kg), and HFα/γ (tesaglitazar, 4 mg/kg). RESULTS: The HF group was overweight, insulin resistant, and had subcutaneous white adipocyte dysfunction. Treatment with PPARα and PPARα/γ reduced body mass, mitigated insulin resistance, and induced browning with increased UCP1-dependent and -independent thermogenesis activation and improved mitochondrial metabolism to support the beige adipocyte phenotype. CONCLUSION: PPARα and dual PPARα/γ activation recruited UCP1+ beige adipocytes and favored UCP1-independent thermogenesis, yielding body mass and insulin sensitivity normalization. Preserved mitochondrial metabolism emerges as a potential target for obesity treatment using PPAR agonists, with possible clinical applications.

Dynamics of chikungunya virus transmission in the first year after its introduction in Brazil: A cohort study in an urban community.

BACKGROUND: The first chikungunya virus (CHIKV) outbreaks during the modern scientific era were identified in the Americas in 2013, reaching high attack rates in Caribbean countries. However, few cohort studies have been performed to characterize the initial dynamics of CHIKV transmission in the New World. METHODOLOGY/PRINCIPAL FINDINGS: To describe the dynamics of CHIKV transmission shortly after its introduction in Brazil, we performed semi-annual serosurveys in a long-term community-based cohort of 652 participants aged ≥5 years in Salvador, Brazil, between Feb-Apr/2014 and Nov/2016-Feb/2017. CHIKV infections were detected using an IgG ELISA. Cumulative seroprevalence and seroincidence were estimated and spatial aggregation of cases was investigated. The first CHIKV infections were identified between Feb-Apr/2015 and Aug-Nov/2015 (incidence: 10.7%) and continued to be detected at low incidence in subsequent surveys (1.7% from Aug-Nov/2015 to Mar-May/2016 and 1.2% from Mar-May/2016 to Nov/206-Feb/2017). The cumulative seroprevalence in the last survey reached 13.3%. It was higher among those aged 30-44 and 45-59 years (16.1% and 15.6%, respectively), compared to younger (12.4% and 11.7% in <15 and 15-29 years, respectively) or older (10.3% in ≥60 years) age groups, but the differences were not statistically significant. The cumulative seroprevalence was similar between men (14.7%) and women (12.5%). Yet, among those aged 15-29 years, men were more often infected than women (18.1% vs. 7.4%, respectively, P = 0.01), while for those aged 30-44, a non-significant opposite trend was observed (9.3% vs. 19.0%, respectively, P = 0.12). Three spatial clusters of cases were detected in the study site and an increased likelihood of CHIKV infection was detected among participants who resided with someone with CHIKV IgG antibodies. CONCLUSIONS/SIGNIFICANCE: Unlike observations in other settings, the initial spread of CHIKV in this large urban center was limited and focal in certain areas, leaving a high proportion of the population susceptible to further outbreaks. Additional investigations are needed to elucidate the factors driving CHIKV spread dynamics, including understanding differences with respect to dengue and Zika viruses, in order to guide prevention and control strategies for coping with future outbreaks.

Bartonella in Norway rats (Rattus norvegicus) from the urban slum environment in Brazil.

Bartonella are rodent-borne bacteria that cause varied human etiologies. Studies on synanthropic rodents are rare, causing gaps in epidemiological knowledge. We tested bloodclot samples from 79 rats from an urban slum in Salvador, Brazil through PCR targeting gltA gene. Nine samples (11.4%) were positive: six had 100% identity with Bartonella sp. isolate JF429580 and 99.5% with B. queenslandensis strain AUST/NH8; three were 100% identical to isolate JF429532 and 99.7% to B. tribocorum. This is the second report on urban rat Bartonella indicating bacterial circulation at detectable rates. Its presence in rats from vulnerable human settlements demands public health attention.

Novel Lactone-Based Insecticides and Drosophila suzukii Management: Synthesis, Potential Action Mechanisms and Selectivity for Non-Target Parasitoids.

Drosophila suzukii, an invasive insect pest, poses a significant threat to various fruit crops. The use of broad-spectrum insecticides to control this pest can reduce the effectiveness of biological control agents, such as the parasitoid Trichopria anastrephae. Here, we evaluated the toxicity of newly synthesized lactone derivatives on D. suzukii and their selectivity towards T. anastrephae. We used in silico approaches to identify potential targets from the most promising molecules in the D. suzukii nervous system and to understand potential differences in susceptibilities between D. suzukii and its parasitoid. Of the nine molecules tested, (rac)-8 and compound 4 demonstrated efficacy against the fly. Exposure to the estimated LC90 of (rac)-8 and compound 4 resulted in a mortality rate of less than 20% for T. anastrephae without impairing the parasitoid's functional parasitism. The in silico predictions suggest that (rac)-8 and compound 4 target gamma amino butyric acid (GABA) receptors and transient receptor potential (TRP) channels of D. suzukii. However, only the reduced interaction with TRP channels in T. anastrephae demonstrated a potential reason for the selectivity of these compounds on the parasitoid. Our findings suggest the potential for integrating (rac)-8 and compound 4 into D. suzukii management practices.

Prevalence of human leptospirosis in the Americas: a systematic review and meta-analysis.

Objective: To describe the prevalence of leptospirosis in the Americas. Methods: A systematic review and meta-analysis, in the period 1930 to 2017, performed on a search of six platforms: PubMed, Web of Science, Scopus, Lilacs, Embase, and Cochrane. Results: The search found 77 publications of which 53 (68%) were from the period 2000-2017. Of the 77, 62 studies were included in the analysis, from North America (11, 17%), Central America (9, 14%), and South America (42, 67%), and 22 studies were from urban areas. Leptospirosis prevalence in the 62 studies analyzed corresponded to 28% (95% CI [23, 32]). Countries with higher prevalence were United States of America (41%), Colombia (29%), and Brazil (21%). The most frequent serovars found were Icterohaemorrhagiae (43 of 77 publications, 55%), Canicola (35, 45%), Pomona (28, 36%), and Grippotyphosa (26, 33%). Conclusions: There is variability of Leptospira species and serovars with heterogenous distribution throughout the Americas, with high prevalence in some countries, highlighting the need for action to control the disease.

Prevalence of human leptospirosis in the Americas: a systematic review and meta-analysis

[ABSTRACT]. Objective. To describe the prevalence of leptospirosis in the Americas. Methods. A systematic review and meta-analysis, in the period 1930 to 2017, performed on a search of six platforms: PubMed, Web of Science, Scopus, Lilacs, Embase, and Cochrane. Results. The search found 77 publications of which 53 (68%) were from the period 2000–2017. Of the 77, 62 studies were included in the analysis, from North America (11, 17%), Central America (9, 14%), and South America (42, 67%), and 22 studies were from urban areas. Leptospirosis prevalence in the 62 studies ana- lyzed corresponded to 28% (95% CI [23, 32]). Countries with higher prevalence were United States of America (41%), Colombia (29%), and Brazil (21%). The most frequent serovars found were Icterohaemorrhagiae (43 of 77 publications, 55%), Canicola (35, 45%), Pomona (28, 36%), and Grippotyphosa (26, 33%). Conclusions. There is variability of Leptospira species and serovars with heterogenous distribution through- out the Americas, with high prevalence in some countries, highlighting the need for action to control the disease.

[RESUMEN]. Objetivo. Describir la prevalencia de la leptospirosis en las Américas. Métodos. Revisión sistemática y metanálisis correspondientes al período 1930-2017, mediante una búsqueda en seis plataformas: PubMed, Web of Science, Scopus, Lilacs, Embase y Cochrane. Resultados. En la búsqueda se encontraron 77 publicaciones, de las que 53 (68%) eran del periodo 2000- 2017. En el análisis se incluyeron 62 de los 77 estudios, correspondientes a América del Norte (11, 17%), Centroamérica (9, 14%) y América del Sur (42, 67%), y 22 estudios correspondientes a zonas urbanas. La prevalencia de la leptospirosis en los 62 estudios analizados fue del 28% (IC del 95% [23, 32]). Los países con mayor prevalencia fueron Estados Unidos de América (41%), Colombia (29%) y Brasil (21%). Las sero- variedades más frecuentes fueron icterohaemorrhagiae (43 de 77 publicaciones, 55%), canicola (35, 45%), pomona (28, 36%) y grippotyphosa (26, 33%). Conclusiones. Se observa variabilidad de especies y serovariedades de Leptospira, con una distribución heterogénea en las Américas y una elevada prevalencia en algunos países, lo que pone de manifiesto la necesidad de adoptar medidas para controlar la enfermedad.

[RESUMO]. Objetivo. Descrever a prevalência da leptospirose nas Américas. Métodos. Uma revisão sistemática e metanálise referente ao período de 1930 a 2017, realizada por meio de busca em seis plataformas: PubMed, Web of Science, Scopus, Lilacs, Embase e Cochrane. Resultados. A pesquisa encontrou 77 publicações, das quais 53 (68%) eram do período de 2000 a 2017. Dos 77 estudos, 62 foram incluídos na análise, da América do Norte (11, equivalente a 17%), América Central (9, equivalente a 14%) e América do Sul (42, equivalente a 67%), e 22 estudos foram realizados em áreas urbanas. A prevalência da leptospirose nos 62 estudos analisados correspondeu a 28% (IC 95% [23, 32]). Os países com maior prevalência foram os Estados Unidos da América (41%), a Colômbia (29%) e o Brasil (21%). Os sorovares mais frequentes encontrados foram Icterohaemorrhagiae (43 de 77 publicações, equivalente a 55%), Canicola (35, equivalente a 45%), Pomona (28, equivalente a 36%) e Grippotyphosa (26, equivalente a 33%). Conclusões. Há variabilidade nas espécies e sorovares de Leptospira, que têm distribuição heterogênea nas Américas e alta prevalência em alguns países, o que destaca a necessidade de ações para controlar a doença.

Exercise prevents obesity by reducing gut-derived inflammatory signals to brown adipocytes in mice.

Gut dysbiosis impairs nonshivering thermogenesis (NST) in obesity. The antiobesogenic effects of exercise training might involve the modulation of gut microbiota and its inflammatory signals to the brown adipose tissue (BAT). This study evaluated whether high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) prevent overweight through reduced gut-derived inflammatory signals to BAT in high-fat-fed mice. Sixty male C57BL/6 mice (3 months old) comprised six experimental groups: control (C) diet group, C diet + HIIT (C-HIIT) group, C diet + MICT (C-MICT) group, high-fat (HF) diet group, HF diet + HIIT (HF-HIIT) group, and HF diet + MICT (HF-MICT) group. The protocols lasted for 10 weeks. HIIT and MICT restored body mass, mitigated glucose intolerance, and prevented hyperinsulinemia in HF-trained groups. A chronic HF diet caused dysbiosis, but HIIT and MICT prevented gut dysbiosis and preserved tight junction (TJ) gene expression. HF-HIIT and HF-MICT groups exhibited a similar pattern of goblet cell distribution, agreeing with the decreased plasma lipopolysaccharide concentrations and interscapular BAT (iBAT) Lbp-Cd14-Tlr4 expression. The lowered Nlrp3 and Il1ß in the HF-HITT and HF-MICT groups complied with iBAT thermogenic capacity maintenance. This study shows reliable evidence that HIIT and MICT prevented overweight by restoring the diversity of the gut microbiota phyla and TJ gene expression, thereby reducing inflammatory signals to brown adipocytes with preserved thermogenic capacity. Both exercise modalities prevented overweight, but HIIT rescued Zo-1 and Jam-a gene expression, exerting more potent anti-inflammatory effects than MICT (reduced LPS concentrations), providing a sustained increase in thermogenesis with 78% less distance traveled.

Peroxisome proliferator-activated receptors as targets to treat metabolic diseases: Focus on the adipose tissue, liver, and pancreas.

The world is experiencing reflections of the intersection of two pandemics: Obesity and coronavirus disease 2019. The prevalence of obesity has tripled since 1975 worldwide, representing substantial public health costs due to its comorbidities. The adipose tissue is the initial site of obesity impairments. During excessive energy intake, it undergoes hyperplasia and hypertrophy until overt inflammation and insulin resistance turn adipocytes into dysfunctional cells that send lipotoxic signals to other organs. The pancreas is one of the organs most affected by obesity. Once lipotoxicity becomes chronic, there is an increase in insulin secretion by pancreatic beta cells, a surrogate for type 2 diabetes mellitus (T2DM). These alterations threaten the survival of the pancreatic islets, which tend to become dysfunctional, reaching exhaustion in the long term. As for the liver, lipotoxicity favors lipogenesis and impairs beta-oxidation, resulting in hepatic steatosis. This silent disease affects around 30% of the worldwide population and can evolve into end-stage liver disease. Although therapy for hepatic steatosis remains to be defined, peroxisome proliferator-activated receptors (PPARs) activation copes with T2DM management. Peroxisome PPARs are transcription factors found at the intersection of several metabolic pathways, leading to insulin resistance relief, improved thermogenesis, and expressive hepatic steatosis mitigation by increasing mitochondrial beta-oxidation. This review aimed to update the potential of PPAR agonists as targets to treat metabolic diseases, focusing on adipose tissue plasticity and hepatic and pancreatic remodeling.

Simplified sewerage to prevent urban leptospirosis transmission: a cluster non-randomised controlled trial protocol in disadvantaged urban communities of Salvador, Brazil.

INTRODUCTION: Leptospirosis is a globally distributed zoonotic and environmentally mediated disease that has emerged as a major health problem in urban slums in developing countries. Its aetiological agent is bacteria of the genus Leptospira, which are mainly spread in the urine of infected rodents, especially in an environment where adequate sanitation facilities are lacking, and it is known that open sewers are key transmission sources of the disease. Therefore, we aim to evaluate the effectiveness of a simplified sewerage intervention in reducing the risk of exposure to contaminated environments and Leptospira infection and to characterise the transmission mechanisms involved. METHODS AND ANALYSIS: This matched quasi-experimental study design using non-randomised intervention and control clusters was designed to assess the effectiveness of an urban simplified sewerage intervention in the low-income communities of Salvador, Brazil. The intervention consists of household-level piped sewerage connections and community engagement and public involvement activities. A cohort of 1400 adult participants will be recruited and grouped into eight clusters consisting of four matched intervention-control pairs with approximately 175 individuals in each cluster in baseline. The primary outcome is the seroincidence of Leptospira infection assessed through five serological measurements: one preintervention (baseline) and four postintervention. As a secondary outcome, we will assess Leptospira load in soil, before and after the intervention. We will also assess Leptospira exposures before and after the intervention, through transmission modelling, accounting for residents' movement, contact with flooding, contaminated soil and water, and rat infestation, to examine whether and how routes of exposure for Leptospira change following the introduction of sanitation. ETHICS AND DISSEMINATION: This study protocol has been reviewed and approved by the ethics boards at the Federal University of Bahia and the Brazilian National Research Ethics Committee. Results will be disseminated through peer-reviewed publications and presentations to implementers, researchers and participating communities. TRIAL REGISTRATION NUMBER: Brazilian Clinical Trials Registry (RBR-8cjjpgm).

Environmental Biofilms from an Urban Community in Salvador, Brazil, Shelter Previously Uncharacterized Saprophytic Leptospira.

Biofilms are complex microecosystems with valuable ecological roles that can shelter a variety of microorganisms. Spirochetes from the genus Leptospira have been observed to form biofilms in vitro, in rural environments, and in the kidneys of reservoir rats. The genus Leptospira is composed of pathogenic and non-pathogenic species, and the description of new species is ongoing due to the advent of whole genome sequencing. Leptospires have increasingly been isolated from water and soil samples. To investigate the presence of Leptospira in environmental biofilms, we collected three distinct samples of biofilms formed in an urban setting with poor sanitation: Pau da Lima, in Salvador, Bahia, Brazil. All biofilm samples were negative for the presence of pathogenic leptospires via conventional PCR, but cultures containing saprophytic Leptospira were identified. Whole genomes were generated and analyzed for twenty isolates obtained from these biofilms. For species identification, we used digital DNA-DNA hybridization (dDDH) and average nucleotide identity (ANI) analysis. The obtained isolates were classified into seven presumptive species from the saprophytic S1 clade. ANI and dDDH analysis suggest that three of those seven species were new. Classical phenotypic tests confirmed the novel isolated bacteria as saprophytic Leptospira. The isolates presented typical morphology and ultrastructure according to scanning electron microscopy and formed biofilms under in vitro conditions. Our data indicate that a diversity of saprophytic Leptospira species survive in the Brazilian poorly sanitized urban environment, in a biofilm lifestyle. We believe our results contribute to a better understanding of Leptospira biology and ecology, considering biofilms as natural environmental reservoirs for leptospires.

Factors associated with differential seropositivity to Leptospira interrogans and Leptospira kirschneri in a high transmission urban setting for leptospirosis in Brazil.

Background: Leptospirosis is a zoonosis caused by pathogenic species of bacteria belonging to the genus Leptospira. Most studies infer the epidemiological patterns of a single serogroup or aggregate all serogroups to estimate overall seropositivity, thus not exploring the risks of exposure to distinct serogroups. The present study aims to delineate the demographic, socioeconomic and environmental factors associated with seropositivity of Leptospira serogroup Icterohaemorraghiae and serogroup Cynopteri in an urban high transmission setting for leptospirosis in Brazil. Methods/Principal Findings: We performed a cross-sectional serological study in five urban informal communities in the city of Salvador, Brazil. During the years 2018, 2020 2021, we recruited 2.808 residents and collected blood samples for serological analysis using microagglutination assays. We used a mixed-effect multinomial logistic regression model to identify risk factors associated with seropositivity for each serogroup. Seropositivity to Cynopteri increased with age in years (OR 1.03; 95% CI 1.01-1.06) and was higher in those living in houses with unplaster walls (exposed brick) (OR 1.68; 95% CI 1.09-2.59) and where cats were present near the household (OR 2.00; 95% CI 1.03-3.88). Seropositivity to Icterohaemorrhagiae also increased with age in years (OR 1.02; 95% CI 1.01-1.03) but was higher in males (OR 1.51; 95% CI 1.09-2.10), in those with work-related exposures (OR 1.71; 95% CI 1.10-2.66) or who had contact with sewage (OR 1.42; 95% CI 1.00-2.03). Spatial analysis showed differences in distribution of seropositivity to serogroups Icterohaemorrhagiae and Cynopteri within the five districts where study communities were situated. Conclusions/Significance: Our data suggests distinct epidemiological patterns associated with serogroups Icterohaemorrhagiae and Cynopteri within the high-risk urban environment for leptospirosis and with differences of spatial niches. Future studies must identify the different pathogenic serogroups circulating in low-income areas, and further evaluate the potential role of cats in the transmission of the serogroup Cynopteri in urban settings.

Chronic Excessive Fructose Intake Maximizes Brown Adipocyte Whitening but Causes Similar White Adipocyte Hypertrophy Than a High-Fat Diet in C57BL/6 Mice.

Objective: This study aimed to evaluate the differential role of a high-fat diet (HF) or high-fructose diet (HFRU) on white adipose tissue and brown adipose tissue remodeling in C57BL/6 mice.Methods: The animals were randomly assigned to receive HF (50% of energy as lipids), HFRU (50% of energy as fructose), or a control diet (C, 10% of energy as lipids) for 12 weeks. Results: The HF group became overweight from the 7th week onwards, but both HF and HFRU groups showed hyperinsulinemia, oral glucose intolerance, and adverse adipose tissue remodeling. HF and HFRU groups showed interscapular brown adipose tissue whitening, tough the reduced QA [nuclei] suggested maximized brown adipocyte dysfunction due to the HFRU diet. In contrast, HF and HFRU diets exerted similar effects upon subcutaneous white adipocytes, with a similar average cross-sectional area. Immunohistochemistry confirmed the whitening enhancement with reduced UCP1 immunodensity in the HFRU group. Conclusion: In conclusion, HF and HFRU diets had indistinguishable effects upon white adipocyte morphology, but the HFRU diet provoked a more pronounced whitening than the HF diet after a 12-week protocol. These results point to the silent and harmful impact that excessive fructose has upon the metabolism of lean mice.

Prevalence of human leptospirosis in the Americas: a systematic review and meta-analysis / Prevalencia de la leptospirosis humana en las Américas: revisión sistemática y metanálisis / Prevalência da leptospirose humana nas Américas: revisão sistemática e metanálise

ABSTRACT Objective. To describe the prevalence of leptospirosis in the Americas. Methods. A systematic review and meta-analysis, in the period 1930 to 2017, performed on a search of six platforms: PubMed, Web of Science, Scopus, Lilacs, Embase, and Cochrane. Results. The search found 77 publications of which 53 (68%) were from the period 2000-2017. Of the 77, 62 studies were included in the analysis, from North America (11, 17%), Central America (9, 14%), and South America (42, 67%), and 22 studies were from urban areas. Leptospirosis prevalence in the 62 studies analyzed corresponded to 28% (95% CI [23, 32]). Countries with higher prevalence were United States of America (41%), Colombia (29%), and Brazil (21%). The most frequent serovars found were Icterohaemorrhagiae (43 of 77 publications, 55%), Canicola (35, 45%), Pomona (28, 36%), and Grippotyphosa (26, 33%). Conclusions. There is variability of Leptospira species and serovars with heterogenous distribution throughout the Americas, with high prevalence in some countries, highlighting the need for action to control the disease.

RESUMEN Objetivo. Describir la prevalencia de la leptospirosis en las Américas. Métodos. Revisión sistemática y metanálisis correspondientes al período 1930-2017, mediante una búsqueda en seis plataformas: PubMed, Web of Science, Scopus, Lilacs, Embase y Cochrane. Resultados. En la búsqueda se encontraron 77 publicaciones, de las que 53 (68%) eran del periodo 2000-2017. En el análisis se incluyeron 62 de los 77 estudios, correspondientes a América del Norte (11, 17%), Centroamérica (9, 14%) y América del Sur (42, 67%), y 22 estudios correspondientes a zonas urbanas. La prevalencia de la leptospirosis en los 62 estudios analizados fue del 28% (IC del 95% [23, 32]). Los países con mayor prevalencia fueron Estados Unidos de América (41%), Colombia (29%) y Brasil (21%). Las serovariedades más frecuentes fueron icterohaemorrhagiae (43 de 77 publicaciones, 55%), canicola (35, 45%), pomona (28, 36%) y grippotyphosa (26, 33%). Conclusiones. Se observa variabilidad de especies y serovariedades de Leptospira, con una distribución heterogénea en las Américas y una elevada prevalencia en algunos países, lo que pone de manifiesto la necesidad de adoptar medidas para controlar la enfermedad.

RESUMO Objetivo. Descrever a prevalência da leptospirose nas Américas. Métodos. Uma revisão sistemática e metanálise referente ao período de 1930 a 2017, realizada por meio de busca em seis plataformas: PubMed, Web of Science, Scopus, Lilacs, Embase e Cochrane. Resultados. A pesquisa encontrou 77 publicações, das quais 53 (68%) eram do período de 2000 a 2017. Dos 77 estudos, 62 foram incluídos na análise, da América do Norte (11, equivalente a 17%), América Central (9, equivalente a 14%) e América do Sul (42, equivalente a 67%), e 22 estudos foram realizados em áreas urbanas. A prevalência da leptospirose nos 62 estudos analisados correspondeu a 28% (IC 95% [23, 32]). Os países com maior prevalência foram os Estados Unidos da América (41%), a Colômbia (29%) e o Brasil (21%). Os sorovares mais frequentes encontrados foram Icterohaemorrhagiae (43 de 77 publicações, equivalente a 55%), Canicola (35, equivalente a 45%), Pomona (28, equivalente a 36%) e Grippotyphosa (26, equivalente a 33%). Conclusões. Há variabilidade nas espécies e sorovares de Leptospira, que têm distribuição heterogênea nas Américas e alta prevalência em alguns países, o que destaca a necessidade de ações para controlar a doença.

Essential Oils as a Source of Ecofriendly Insecticides for Drosophila suzukii (Diptera: Drosophilidae) and Their Potential Non-Target Effects.

The spotted wing drosophila (Drosophila suzukii) is one of the main invasive pests of small fruits in the world. Thus, 19 essential oils (EOs) were selected to analyze the effects through toxicity and repellency on oviposition and D. suzukii adults. In addition, their lethal and sublethal effects on the pupal endoparasitoid Trichopria anastrephae were evaluated. The EOs of C. flexuosus and Mentha spp. had the highest toxicity observed in the topical application bioassay for D. suzukii. In contrast, the EOs of C. verum, C. citratus QT citratus, and C. winterianus showed the highest toxicity in the ingestion bioassay for D. suzukii. The dry residues of C. verum and C. citratus QT citratus reduced the oviposition of D. suzukii. In the repellency bioassays, the 19 EOs analyzed repelled ≅ 90% of the D. suzukii females. All EOs evaluated using the LC90 values of the products provided mortality of less than 20% of T. anastrephae adults and did not cause a reduction in the parasitism of surviving T. anastrephae females. We conclude that the EOs evaluated have the potential to be used in the management of D. suzukii. They can also serve as selective active ingredients for the formulation and synthesis of new biopesticides.

Structural factors associated with SARS-CoV-2 infection risk in an urban slum setting in Salvador, Brazil: A cross-sectional survey.

BACKGROUND: The structural environment of urban slums, including physical, demographic, and socioeconomic attributes, renders inhabitants more vulnerable to Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection. Yet, little is known about the specific determinants that contribute to high transmission within these communities. We therefore aimed to investigate SARS-CoV-2 seroprevalence in an urban slum in Brazil. METHODS AND FINDINGS: We performed a cross-sectional serosurvey of an established cohort of 2,041 urban slum residents from the city of Salvador, Brazil between November 2020 and February 2021, following the first Coronavirus Disease 2019 (COVID-19) pandemic wave in the country and during the onset of the second wave. The median age in this population was 29 years (interquartile range [IQR] 16 to 44); most participants reported their ethnicity as Black (51.5%) or Brown (41.7%), and 58.5% were female. The median size of participating households was 3 (IQR 2 to 4), with a median daily per capita income of 2.32 (IQR 0.33-5.15) US Dollars. The main outcome measure was presence of IgG against the SARS-CoV-2 spike protein. We implemented multilevel models with random intercepts for each household to estimate seroprevalence and associated risk factors, adjusting for the sensitivity and specificity of the assay, and the age and gender distribution of our study population. We identified high seroprevalence (47.9%, 95% confidence interval [CI] 44.2% to 52.1%), particularly among female residents (50.3% [95% CI 46.3% to 54.8%] versus 44.6% [95% CI 40.1% to 49.4%] among male residents, p < 0.01) and among children (54.4% [95% CI 49.6% to 59.3%] versus 45.4% [95% CI 41.5% to 49.7%] among adults, p < 0.01). Adults residing in households with children were more likely to be seropositive (48.6% [95% CI 44.8% to 52.3%] versus 40.7% [95% CI 37.2% to 44.3%], p < 0.01). Women who were unemployed and living below the poverty threshold (daily per capita household income <$1.25) were more likely to be seropositive compared to men with the same employment and income status (53.9% [95% CI 47.0% to 60.6%] versus 32.9% [95% CI 23.2% to 44.3%], p < 0.01). Participation in the study was voluntary, which may limit the generalizability of our findings. CONCLUSIONS: Prior to the peak of the second wave of the COVID-19 pandemic, cumulative incidence as assessed by serology approached 50% in a Brazilian urban slum population. In contrast to observations from industrialized countries, SARS-CoV-2 incidence was highest among children, as well as women living in extreme poverty. These findings emphasize the need for targeted interventions that provide safe environments for children and mitigate the structural risks posed by crowding and poverty for the most vulnerable residents of urban slum communities.

Linking rattiness, geography and environmental degradation to spillover Leptospira infections in marginalised urban settings: An eco-epidemiological community-based cohort study in Brazil.

Background: Zoonotic spillover from animal reservoirs is responsible for a significant global public health burden, but the processes that promote spillover events are poorly understood in complex urban settings. Endemic transmission of Leptospira, the agent of leptospirosis, in marginalised urban communities occurs through human exposure to an environment contaminated by bacteria shed in the urine of the rat reservoir. However, it is unclear to what extent transmission is driven by variation in the distribution of rats or by the dispersal of bacteria in rainwater runoff and overflow from open sewer systems. Methods: We conducted an eco-epidemiological study in a high-risk community in Salvador, Brazil, by prospectively following a cohort of 1401 residents to ascertain serological evidence for leptospiral infections. A concurrent rat ecology study was used to collect information on the fine-scale spatial distribution of 'rattiness', our proxy for rat abundance and exposure of interest. We developed and applied a novel geostatistical framework for joint spatial modelling of multiple indices of disease reservoir abundance and human infection risk. Results: The estimated infection rate was 51.4 (95%CI 40.4, 64.2) infections per 1000 follow-up events. Infection risk increased with age until 30 years of age and was associated with male gender. Rattiness was positively associated with infection risk for residents across the entire study area, but this effect was stronger in higher elevation areas (OR 3.27 95% CI 1.68, 19.07) than in lower elevation areas (OR 1.14 95% CI 1.05, 1.53). Conclusions: These findings suggest that, while frequent flooding events may disperse bacteria in regions of low elevation, environmental risk in higher elevation areas is more localised and directly driven by the distribution of local rat populations. The modelling framework developed may have broad applications in delineating complex animal-environment-human interactions during zoonotic spillover and identifying opportunities for public health intervention. Funding: This work was supported by the Oswaldo Cruz Foundation and Secretariat of Health Surveillance, Brazilian Ministry of Health, the National Institutes of Health of the United States (grant numbers F31 AI114245, R01 AI052473, U01 AI088752, R01 TW009504 and R25 TW009338); the Wellcome Trust (102330/Z/13/Z), and by the Fundação de Amparo à Pesquisa do Estado da Bahia (FAPESB/JCB0020/2016). MTE was supported by a Medical Research UK doctorate studentship. FBS participated in this study under a FAPESB doctorate scholarship.