Salmonella spp. in pet reptiles in Portugal : prevalence and chlorhexidine gluconate antimicrobial efficacy

Research Areas: Infectious Diseases ; Pharmacology & PharmacyABSTRACT - A fraction of human Salmonella infections is associated with direct contact with reptiles, yet the number of reptile-associated Salmonellosis cases are believed to be underestimated. Existing data on Salmonella spp. transmission by reptiles in Portugal is extremely scarce. The aim of the present work was to evaluate the prevalence of Salmonella spp. in pet reptiles (snakes, turtles, and lizards), as well as evaluate the isolates’ antimicrobial resistance and virulence profiles, including their ability to form biofilm in the air-liquid interface. Additionally, the antimicrobial effect of chlorhexidine gluconate on the isolates was tested. Salmonella was isolated in 41% of the animals sampled and isolates revealed low levels of antimicrobial resistance. Hemolytic and lypolytic phenotypes were detected in all isolates. The majority (90.63%) of the Salmonella isolates were positive for the formation of pellicle in the air-liquid interface. Results indicate chlorhexidine gluconate is an effective antimicrobial agent, against the isolates in both their planktonic and biofilm forms, demonstrating a bactericidal effect in 84.37% of the Salmonella isolates. This study highlights the possible role of pet reptiles in the transmission of non-typhoidal Salmonella to humans, a serious and increasingly relevant route of exposure in the Salmonella public health framework.info:eu-repo/semantics/publishedVersio

Biocide Use for the Control of Non-Typhoidal <em>Salmonella</em> in the Food-Producing Animal Scenario: A Primary Food Production to Fork Perspective

Biocides are a group of substances commonly used in food production settings to destroy or control a wide range of microorganisms, which can be present in food of animal origin, since contamination can occur in the several steps of the food production chains. In order to achieve the desired results, the users of biocides must first understand the diverse characteristics of such compounds, mainly the usage requirements, limitations, and the factors affecting the activity of biocides. Food-producing animals and their products, namely meat and eggs, represent a major source of non-typhoidal Salmonella for humans and are associated with foodborne outbreaks worldwide. The prevention of cross-contamination, which can occur in any step of the food production chain, is essential for the ultimate objective of producing safe food products. The correct use of biocides, along with good hygiene and manufacturing practices, is one of the pillars of Salmonella spp. control and should be implemented in all steps of the food production chain. The present chapter reviews the accumulated knowledge on the use of biocides to control non-typhoidal Salmonella, from a farm to fork standpoint, along with the possible impacts on human health arising from improper use

Resistance and virulence distribution in enterococci isolated from broilers reared in two farming systems

Research Areas: Veterinary SciencesBackground: The impact of enterococci in human health has been growing for the last decades, mainly due to their resistance to several antimicrobial agents. Human consumption of contaminated meat, especially poultry, has been identified as a possible route of transmission. The aim of the present study was to evaluate and compare the antimicrobial resistance profiles and virulence genes of enterococci isolated from Portuguese conventional and free-range broiler farms. Results: Antibiotic susceptibility testing showed high frequencies of resistance to tetracycline in both farming systems. Resistance to erythromycin and gentamicin were detected in about half of the isolates. Resistance to penicillin was the less frequently observed and no vancomycin resistant isolates were identified. The majority of the enterococcal isolates, from either farming systems, were resistant to more than one antibiotic, and no statistical associations were found, except for penicillin resistance which associated with the genetic clusters. No differences were found between farming systems regarding the prevalence of tet(M), erm(B), aac (6′)-Ie-aph (2″)-Ia and pbp5 genes, nevertheless pbp5 prevalence was associated with the different genetic clusters. Hemolytic activity was identified in 26.47% of all isolates and gelatinase activity in 50%. The gelE gene was identified in the majority of the isolates, whereas esp and agg genes were rarely detected. The cylA determinant was not detected in any of the isolates. Conclusions: Overall, results suggest that similar resistance patterns and virulence genes can be found in both farming systems, though enterococci in free-range conditions should be less prone to acquire further resistance genes.info:eu-repo/semantics/publishedVersio

Tratamentos para a Epilepsia: Uma Análise da Literatura Recente

The text provides a comprehensive analysis of the various therapeutic approaches to epilepsy, highlighting both significant advancements made and persistent challenges that remain in this area. While the identification of potential therapeutic targets through an understanding of epilepsy genetics has been a crucial breakthrough, current antiepileptic medications face significant limitations, such as limited long-term efficacy and adverse side effects. This underscores the urgent need for therapeutic innovation, addressing not only genetic aspects but also the pathophysiology of the disease. Diversified therapeutic alternatives, such as surgery, special diets, and neuromodulation therapies, offer hope for medication-resistant patients. Additionally, emerging approaches like chronopharmacology and the use of cannabidiol show promise, albeit requiring further research to validate their efficacy and safety. The growing understanding of the role of the intestinal microbiota in epilepsy also suggests new therapeutic possibilities, despite gaps in our understanding of underlying mechanisms. In summary, a personalized, multidisciplinary approach, coupled with collaborations between researchers, physicians, and the industry, is essential to translate scientific advancements into more effective and accessible therapies, offering hope for a better future for all epilepsy patients.O texto analisa de maneira abrangente as diferentes estratégias terapêuticas para o tratamento da epilepsia, destacando tanto os avanços significativos quanto os desafios persistentes nessa área. Apesar da identificação de potenciais alvos terapêuticos por meio da compreensão da genética da epilepsia, os medicamentos antiepilépticos atuais enfrentam limitações, como eficácia a longo prazo limitada e efeitos colaterais adversos. Isso ressalta a necessidade urgente de inovação terapêutica, considerando não apenas os aspectos genéticos, mas também a fisiopatologia da doença. Alternativas terapêuticas diversificadas, como cirurgia, dietas especiais e terapias de neuromodulação, oferecem esperança para pacientes resistentes a medicamentos. Além disso, abordagens emergentes, como a cronofarmacologia e o uso de canabidiol, mostram promessas, embora exijam mais pesquisas para validar sua eficácia e segurança. A crescente compreensão do papel da microbiota intestinal na epilepsia também sugere novas possibilidades terapêuticas, apesar de lacunas em nosso entendimento dos mecanismos subjacentes. Em suma, uma abordagem personalizada e multidisciplinar, aliada a colaborações entre pesquisadores, médicos e a indústria, é essencial para transformar avanços científicos em terapias mais eficazes e acessíveis, oferecendo esperança para um futuro melhor para todos os pacientes com epilepsia

Moderate reductions in dissolved oxygen may compromise performance in an ecologically-important estuarine invertebrate

Coastal ecosystems, including estuaries, are increasingly pressured by expanding hypoxic regions as a result of human activities such as increased release of nutrients and global warming. Hypoxia is often defined as oxygen concentrations below 2 mL O2 L−1. However, taxa vary markedly in their sensitivity to hypoxia and can be affected by a broad spectrum of low oxygen levels. To better understand how reduced oxygen availability impacts physiological and molecular processes in invertebrates, we investigated responses of an estuarine amphipod to an ecologically-relevant level of moderate hypoxia (~2.6 mL O2 L−1) or severe hypoxia (~1.3 mL O2 L−1). Moderate hypoxia elicited a reduction in aerobic scope, and widespread changes to gene expression, including upregulation of metabolic genes and stress proteins. Under severe hypoxia, a marked hyperventilatory response associated with maintenance of aerobic performance was accompanied by a muted transcriptional response. This included a return of metabolic genes to baseline levels of expression and downregulation of transcripts involved in protein synthesis, most of which indicate recourse to hypometabolism and/or physiological impairment. We conclude that adverse ecological effects may occur under moderate hypoxia through compromised individual performance and, therefore, even modest declines in future oxygen levels may pose a significant challenge to coastal ecosystems

Upregulated expression of interleukin-8, RANTES and chemokine receptors in human astrocytic cells infected with HIV-1

Human immunodeficiency virus (HIV) infection of the central nervous system (CNS) affects primarily microglial cells and astrocytes. Infection of these latter cells occurs independently of CD4 and is characterised by preferential accumulation of 2 Kb mRNA, encoding mostly Nef, and by low levels of 4.5 and 9 Kb RNAs. We have investigated the potential role of chronic HIV infection of human astrocytic cells on the expression of pro-inflammatory cytokines, chemokines and their receptors by comparing the infected TH4-7-5 with its parental uninfected 85HG66 cell lines. Upregulated levels of tumour necrosis factor-alpha (TNF-alpha) and of certain chemokines, namely interleukin-8 (IL-8) and regulated upon activation normal T cell expressed and secreted (RANTES), were observed in the infected versus uninfected cells, whereas monocyte chemotactic protein-1 (MCP-1) was comparably expressed in both cell lines. This pattern of expression was confirmed in primary foetal astrocytes transiently transfected with HIV. In addition, CXCR1, CXCR2 and CCR2b, receptors for IL-8 and MCP-1, respectively, were also found to be upregulated in TH4-7-5 versus 85HG66. CXCR4, the receptor of stromal cell derived factor-1 (SDF-1) and co-receptor for syncytium inducing HIVs, was comparably expressed in infected and uninfected astrocytic cells, whereas CCR5 was not detected in either cell line. Furthermore, treatment of TH4-7-5 cells with TNF-alpha or IL-1beta stimulated RNA and protein secretion of IL-8, MCP-1, and RANTES as well as HIV expression. Thus, our findings suggest that HIV infection of astrocytic cells can contribute to the establishment of a chronic inflammatory state in the CNS, eventually resulting in HIV encephalitis, by increasing the secretion of pro-inflammatory cytokines, such as TNF-alpha and several chemokines. Overexpression of chemokine receptors including CCR2b, CXCR1 and CXCR2 in infected astrocytic cells may contribute to HIV-induced damage of the CNS via autocrine/paracrine activation of astrocyte

Tumor necrosis factor-alpha drives HIV-1 replication in U937 cell clones and upregulates CXCR4

U937 cell clones in which efficient (plus) vs poor (minus) replication of HIV-1 occurs have been described. We evaluated the role of host factors in their differential ability to support HIV-1 replication. Plus clones constitutively produced TNF-alpha and viral replication was inhibited by neutralization of endogenous TNF-alpha. However, HIV-1 replication was strongly upregulated in minus clones by exogenous TNF-alpha, which also further accelerated the kinetics of infection in plus clones. We observed an increased accumulation of proviral DNA within one round of HIV-1 replication following TNF-a treatment of plus cells. This effect was associated with increased surface density of CXCR4 in both plus and minus clones. Our results identify TNF-alpha as one correlate that contributes to the higher ability of U937-plus clones to sustain HIV-1 replication. Furthermore, we suggest that TNF-alpha may affect steps of the viral life cycle that occur earlier than transcription and also enhance HIV-1 replication by increasing the surface density of CXCR