Effect of Probiotic Lacticaseibacillus rhamnosus LB1.5 on Anxiety-like Behavior, Neuroprotection and Neuroinflammation Markers of Male Mice Fed a High-Fat Diet.

Probiotic supplementation has been identified as a potential target to reduce inflammatory mediators associated with obesity. Therefore, this study assessed the effect of probiotic Lacticaseibacillus rhamnosus LB1.5 on anxiety-like behavior, gene expression in the prefrontal cortex, and neuroinflammation in the cerebral cortex and hippocampus of male mice fed a high-fat diet. Mice aged 21 days were divided into four groups: control (CONT), control plus probiotic (CONT + PROB), high-fat diet (HFD), and high-fat diet plus probiotic (HFD + PROB), and fed for 13 weeks. The probiotic Lact. rhamnosus 1.5 (3.1 × 108 CFU/mL, derived from raw buffalo milk) was administered by gavage three times a week. Probiotic supplementation provided an anxiolytic effect in CONT and HFD. The IL-6 showed lower levels after probiotic supplementation in the HFD. Regarding immunoreactivity for GFAP in the cerebral cortex, we demonstrated that animals HFD-fed had a reduction in cells number compared to CONT. In the hippocampus, we found an interaction between diet and supplementation, as well as an effect of probiotic supplementation. A higher number of Th positive cells was observed in the cerebral cortex in mice fed HFD. Lact. rhamnosus LB1.5 supplementation decreased serum IL-6 levels in HFD-fed mice and promoted a reduction in anxiety-like behavior.

Análise da influência de determinantes meteorológicos na periodicidade de epidemias de dengue em Porto Alegre / Analysis of the influence of meteorological determinants on the periodicity of dengue epidemics in Porto Alegre

A incidência da dengue, doença viral transmitida pelo mosquito Aedes aegypti, vem crescendo em Porto Alegre ao longo dos anos, com recorde de casos registrados em 2022. Epidemias da doença parecem ocorrer de forma cíclica no município, com registros a cada três anos. Dada a influência de fatores climáticos no ciclo de vida do vetor, este trabalho buscou analisar a influência de determinantes meteorológicos na periodicidade de epidemias de dengue na capital gaúcha entre 2010 e 2022. Análises descritivas foram realizadas para averiguar o padrão dos indicadores climáticos e dos casos de dengue ao longo dos anos, ao passo que análises estatísticas foram feitas para avaliar a correlação entre os fatores climáticos e os casos autóctones registrados entre 2016 e 2022. Os resultados obtidos não apontaram padrões meteorológicos que se repetem a cada três anos e que poderiam explicar a ciclicidade observada. Ainda, não foram constatadas correlações entre temperatura, umidade e pluviosidade com casos autóctones de dengue no município, ao menos em nível quadrimestral. Para além destas análises, constatou-se expressivo aumento de casos em 2022, apesar dos esforços de controle desempenhados pelo poder público, o que aponta a necessidade de maior investimento em educação em saúde para a população. (AU)

The incidence of dengue, a viral disease transmitted by the Aedes aegypti mosquito, has been increasing in Porto Alegre over the years, with a record number of cases reported in 2022. Epidemics of the disease seem to occur cyclically in the city, with reports every three years. Given the influence of climatic factors on the vector's life cycle, this study aimed to analyze the influence of meteorological determinants on the periodicity of dengue epidemics in Porto Alegre between 2010 and 2022. Descriptive analyses were used to investigate the pattern of climatic indicators and dengue cases over the years, while statistical analyses were performed to evaluate the correlation between climatic factors and autochthonous cases registered between 2016 and 2022. The results did not point out meteorological patterns that repeat every three years and could explain the observed cyclicity. Furthermore, no correlations were found between temperature, humidity and rainfall and autochthonous dengue cases in the city, at least on a four-monthly basis. Beyond these analyses, a significant increase in dengue cases was observed in 2022, despite the efforts of the public authorities to control the disease, which highlights the need for greater investment in health education for the population. (AU)

Triclosan-loaded chitosan as antibacterial agent for adhesive resin.

OBJECTIVES: The aim of this study was to formulate and to evaluate the immediate and long-term physical, chemical and antibacterial properties of an experimental adhesive resin with chitosan or triclosan-loaded chitosan. MATERIALS AND METHODS: Chitosan, triclosan and triclosan-loaded chitosan were evaluated for scanning electron microscopy (SEM) and micro-Raman spectroscopy. An experimental adhesive resin was formulated with methacrylate monomers and photoinitiators. Chitosan or triclosan-loaded chitosan were added at 2 (GQ2% and GQT2%) or 5 (GQ5% and GQT5%) wt.% in the base resin. The base resin was used as control (GCTRL). The adhesives were evaluated for degree of conversion (DC), Knoop hardness (KHN), softening in solvent (ΔKHN), immediate and long-term microtensile bond-strength (µ-TBS) and antibacterial activity. RESULTS: SEM indicated triclosan sticks and chitosan porosity. Triclosan-loaded chitosan presented structures on chitosan. Micro-Raman indicated no chemical interaction between chitosan and triclosan. There was no difference among groups for DC (p > 0.05). Initial KHN ranged from 17.36 (±1.56) to 20.38 (±1.72), with higher value for GQT5% compared to GCTRL (p < 0.05). GCTRL presented the lowest ΔKHN% (p < 0.05). There were no differences in the immediate or long-term µ-TBS (p > 0.05). GCTRL and GQ2% decreased the µ-TBS after storage (p < 0.05). Chitosan groups showed higher biofilm formation (p < 0.05). Triclosan-loaded chitosan groups presented lower biofilm formation (p < 0.05). There was no activity against planktonic bacteria regardless the time of evaluation (p > 0.05). CONCLUSION: Triclosan-loaded chitosan at 5 wt.% addition in an experimental adhesive resin showed reliable properties, with the highest antibacterial activity immediately and after six months, and induced dentin/adhesive interface stability over time. CLINICAL SIGNIFICANCE: Triclosan-loaded chitosan groups showed antibacterial activity immediately and over time and induced dentin/adhesive interface stability, may positively affecting long-lasting marginal sealing.

Detecção de genes de enterotoxinas em staphylococcus aureus isolados de leite cru de búfala / Detection of enterotoxin genes in staphylococcus aureus isolated from raw buffalo milk

Atualmente, a principal causa de intoxicação alimentar está associada ao consumo de alimentos contendo enterotoxinas produzidas, principalmente, pela espécie Staphylococcus aureus. Vários estudos descrevem a prevalência de S. aureus e suas enterotoxinas no leite bovino. Entretanto, essas informações em leite bubalino ainda são escassas. O crescente consumo de derivados de leite bubalino alerta para a questão de saúde pública, visto que essas enterotoxinas são resistentes aos processos térmicos pelos quais é submetida a sua matéria-prima. O objetivo deste estudo foi analisar a presença de genes que codificam enterotoxinas estafilocócicas em isolados de S. aureus obtidos de leite cru de búfala. (AU)

Activity of the antimicrobial peptide P34 against bovine alphaherpesvirus type 1 / Atividade do peptídeo antimicrobiano P34 contra o alfaherpesvírus bovino tipo 1

ABSTRACT: Previous studies have demonstrated the antimicrobial activity of the peptide P34. In this study, the antiviral potential of P34 and the in vitro mechanism of action were investigated against bovine alphaherpesvirus type 1 (BoHV1). P34 exhibited low toxicity, a high selectivity index (22.9) and a percentage of inhibition of up to 100% in MDBK cells. Results from antiviral assays indicated that P34 did not interact with cell receptors, but it was able to inhibit the viral penetration immediately after pre-adsorption. In addition, BoHV1 growth curve in MDBK cells in the presence of P34 revealed a significant reduction in virus titer only 8h post-infection, also suggesting an important role at late stages of the replicative cycle. Virucidal effect was observed only in cytotoxic concentrations of the peptide. These findings showed that the antimicrobial peptide P34 may be considered as a potential novel inhibitor of in vitro herpesviruses and must encourage further investigation of its antiherpetic activity in animal models as well as against a wide spectrum of viruses.

RESUMO: A atividade antimicrobiana do peptídeo P34 já foi previamente demonstrada. Neste estudo, o potencial antiviral do P34 e o mecanismo de ação in vitro contra o alfaherpesvírus bovino tipo 1 (BoHV1) foram investigados. O P34 exibiu baixa toxicidade, alto índice de seletividade (22.9) e percentagem de inibição viral de até 100% em células MDBK. Os resultados dos ensaios antivirais indicaram que não interage com receptores celulares, mas é capaz de inibir a penetração viral, imediatamente após a pré-adsorção. Além disso, a curva de crescimento do BoHV1 em células MDBK na presença do P34 revelou uma significativa redução no título somente após 8h de infecção, sugerindo também uma importante atividade do peptídeo nas fases finais do ciclo replicativo. Efeito virucida frente / BoHV1 foi observado apenas em concentrações citotóxicas do peptídeo. Os dados obtidos indicam que o peptídeo antimicrobiano P34 pode ser considerado um potencial composto inibidor de herpesvírus, in vitro, e estimulam posteriores investigações sobre sua atividade anti-herpética em modelos animais, bem como contra outros vírus.

Antiviral activity of a Bacillus sp: P34 peptide against pathogenic viruses of domestic animals

P34 is an antimicrobial peptide produced by a Bacillus sp. strain isolated from the intestinal contents of a fish in the Brazilian Amazon basin with reported antibacterial activity. The aim of this work was to evaluate the peptide P34 for its in vitro antiviral properties against canine adenovirus type 2 (CAV-2), canine coronavirus (CCoV), canine distemper virus (CDV), canine parvovirus type 2 (CPV-2), equine arteritis virus (EAV), equine influenza virus (EIV), feline calicivirus (FCV) and feline herpesvirus type 1 (FHV-1). The results showed that the peptide P34 exhibited antiviral activity against EAV and FHV-1. The peptide P34 inhibited the replication of EAV by 99.9% and FHV-1 by 94.4%. Virucidal activity was detected only against EAV. When P34 and EAV were incubated for 6 h at 37 °C the viral titer reduced from 10(4.5) TCID50 to 10(2.75) TCID50, showing a percent of inhibition of 98.6%. In conclusion, our results demonstrated that P34 inhibited EAV and FHV-1 replication in infected cell cultures and it showed virucidal activity against EAV. Since there is documented resistance to the current drugs used against herpesviruses and there is no treatment for equine viral arteritis, it is advisable to search for new antiviral compounds to overcome these infections.

Mode of action of antimicrobial peptide P45 on Listeria monocytogenes.

The mode of action of an antimicrobial peptide produced by Bacillus sp. P45 isolated from the intestine of the Amazonian basin fish Piaractus mesopotamicus was investigated. The antimicrobial peptide was purified from culture supernatants by precipitation with ammonium sulfate and gel filtration chromatography. The peptide has an EC(50) of 300 AU (activity units) ml(-1) and kills all viable cells of Listeria monocytogenes with a concentration of 800 AU ml(-1). A decrease in OD was observed when L. monocytogenes cultures were treated with the peptide, suggesting that cells were lysed. Transmission electron microscopy showed damage of the cell envelope and loss of protoplasmic material. The peptide P45 was bactericidal and bacteriolytic to L. monocytogenes. There is evidence that the mode of action is interfering at cell membranes and the cell wall. The knowledge of the mode of action of antimicrobial peptides is an essential step to consider their utilization in food or clinic.