TEDE Coleção: Mestrado em Ciência Animal

Influência da variabilidade geográfica sobre o potencial neurotóxico e reatividade cruzada com antiveneno comercial de venenos de subespécies de Crotalus durissus (Viperidae: Crotalinae) distribuídas no Brasil

Mon, 23 Feb 2026 00:00:00 GMT

Título: Influência da variabilidade geográfica sobre o potencial neurotóxico e reatividade cruzada com antiveneno comercial de venenos de subespécies de Crotalus durissus (Viperidae: Crotalinae) distribuídas no Brasil Autor: Demico, Poliana de Jesus Primeiro orientador: Floriano, Rafael Stuani Abstract: Envenomation by Crotalus snakes are known for causing significant neurotoxic and myotoxic effects, primarily attributed to crotoxin, a phospholipase A2 (PLA2) toxin that constitutes 70–90% of these venoms. Recent studies have demonstrated that geographic variability affects the PLA2 compositional profile of C. d. terrificus and C. d. collilineatus venoms, revealing a greater complexity of isoforms in specimens from the central-west and southeastern regions of Brazil. In this study, we assessed how geographic variability affects the neuromuscular activity of venoms from Crotalus durissus cascavella (CDV), C. d. collilineatus (CDC), C. d. ruruima (CDR), and C. d. terrificus (CDT), including the cross-reactivity of these venoms with commercial anti-Crotalus antivenom (AV) and PLA2 inhibition by varespladib (VPL). PLA2 activity was measured through spectrophotometry using 3-octanoyloxy benzoic acid as an artificial substrate. The mouse phrenic nerve-diaphragm preparation was set up in an Ugo Basile SRL myographic system under a tension of 1 g. Twitches were induced through supramaximal stimuli (0.1 Hz, 0.2 ms, ~6 V) and recorded with a DY1 force displacement transducer connected to a DataCapsule-Evo and LabScribe4 software. Results are expressed as mean ± SD (n=3–4). The CDR venom exhibited the highest PLA2 activity (75.5±2 ΔA425nm/min, n=3), while the CDV venom demonstrated greater sensitivity to VPL (0.3 mM), resulting in a ~97% inhibition of its PLA2 activity (p<0.05 compared to venom alone, n=3). CDC venom (10–100 μg/ml) induced significant neuromuscular facilitation, followed by a complete blockade within a 120 min incubation period. In contrast, CDV venom (10–100 μg/ml) exhibited greater potency at the neuromuscular junction, fully blocking twitch responses at all concentrations within 80–110 min. CDR venom resulted in a complete blockade only at the highest concentration of 100 μg/ml, which occurred within approximately 110 minutes. AV (antivenom:venom ratio 1:1.5 v/w) demonstrated partial efficacy against the venoms of both CDT and CDV (30 g/ml), avoiding the occurrence of 90% blockade for each. However, it exhibited limited cross-reactivity when tested against CDC and CDR (30 g/ml) venoms. In contrast, VPL at a concentration of 0.3 mM effectively inhibited the 90% blockade induced by both CDT and CDV (30 µg/ml) venoms, as well as avoiding the 50% blockade for CDC (30 µg/ml). The immunoreactivity with antivenom revealed the major enzymatic groups in these venoms, with C. d. cascavella and C. d. ruruima venoms being positive for crotamina. In conclusion, the venoms of these subspecies exhibit significant variability in their neuromuscular effects observed. Inhibition of PLA2 activity by VPL resulted in a marked reduction of the neuromuscular blockade induced by these venoms. Furthermore, VPL demonstrated greater efficacy than AV in mitigating the neuromuscular actions associated with CDC, CDT, and CDV venoms. Instituição: Universidade do Oeste Paulista Tipo do documento: Dissertação

Avaliação microbiológica e molecular de Escherichia coli isoladas em carne moída bovina no interior de São Paulo

Fri, 10 Oct 2025 00:00:00 GMT

Título: Avaliação microbiológica e molecular de Escherichia coli isoladas em carne moída bovina no interior de São Paulo Autor: Alves, Maria do Socorro Primeiro orientador: Eller, Lizziane Kretli Winkelströter Abstract: Escherichia coli (E. coli) is a Gram-negative bacterium of the Enterobacteriaceae family with high genetic plasticity. Pathogenic strains produce toxins, adhesins, capsules, biofilms, and β-lactamases, which confer antimicrobial resistance. This study aimed to assess the presence of E. coli in ground beef sold in Presidente Prudente, São Paulo, and to characterize the virulence and resistance genes at the molecular level. A total of 51 samples of ground beef from butcher shops registered with the Health Surveillance Agency were analyzed. Bacterial identification was performed using microbiological, biochemical, and polymerase chain reaction methods. These methods included the detection of the papC, fimH, kpsMTII, fliC, blaTEM, blaSHV, blaCTX-M, and blaOXA genes, as well as phylogenetic classification (groups A, B1, B2, and D). Fifty-five isolates confirmed as E. coli were obtained, predominantly from group B2 (54.5%). The fimH (100%), papC (83.6%), and fliC (80%) genes were the most prevalent. All isolates showed biofilm formation with a weak adherence pattern. Resistance was low, with tetracycline resistance being the most prevalent (12.7%). Most isolates presented multiple resistance genes (mean of 2.27). It is concluded that ground meat can carry virulent and resistant strains of E. coli, highlighting the importance of hygiene measures and continuous microbiological surveillance. Instituição: Universidade do Oeste Paulista Tipo do documento: Dissertação

Qualidade microbiológica, composição nutricional e estabilidade oxidativa de filés de tilápia congelados disponíveis no varejo

Tue, 24 Mar 2026 00:00:00 GMT

Título: Qualidade microbiológica, composição nutricional e estabilidade oxidativa de filés de tilápia congelados disponíveis no varejo Autor: Leite, Quézia Hadassa Machado Primeiro orientador: Zundt, Marilice Abstract: Global tilapia consumption reached approximately 7.1 million tons in 2024, with an annual growth rate of 5.7%, consolidating the species as one of the main global protein sources. However, the precariousness in food safety represents a massive economic barrier, with annual health costs exceeding US$ 14.1 billion and losses from recall events exceeding US$ 100 million for the industry. Given this scenario, the present study evaluated the physicochemical, microbiological, and oxidative quality of frozen tilapia fillets commercialized in retail markets over storage time (D0, D3, D7, and D14).The experimental design was completely randomized in a factorial scheme (brand × storage time), with data subjected to analysis of variance (ANOVA) and means compared using Tukey’s test (p < 0.05). A significant brand effect was observed on proximate composition, with variations in crude protein and extract contents, while moisture and ash showed no significant variations among brands and storage times. Although the glazing percentage predominantly met current legislation, microbiological analyses revealed critical non-conformities in part of the samples, regardless of storage time, indicating serious deficiencies in hygienic-sanitary control at the retail level. Oxidative stability, assessed by TBARS, showed progressive deterioration, with a significant increase in values at D7 and D14 and a significant brand × time interaction (p < 0.05). More than simple qualitative heterogeneity, the presence of pathogens and the observed oxidative instability expose vulnerabilities that directly compromise public health and the economic sustainability of the sector. The results reinforce that compliance with microbiological standards is not merely a legal requirement but a vital commercial survival strategy, demanding the immediate standardization of best practice protocols and the intensification of sanitary surveillance in the retail cold chain. Instituição: Universidade do Oeste Paulista Tipo do documento: Dissertação

Influência do treinamento aeróbico e resistido na síndrome metabólica, desempenho físico, estresse oxidativo e componentes da matriz extracelular muscular: estudo pré clínico

Fri, 16 Oct 2026 00:00:00 GMT

Título: Influência do treinamento aeróbico e resistido na síndrome metabólica, desempenho físico, estresse oxidativo e componentes da matriz extracelular muscular: estudo pré clínico Autor: Ferreira, Isabelle Tiburcio Pecin Primeiro orientador: Pacagnelli, Francis Lopes Abstract: Introduction: Metabolic syndrome (MS), characterized by obesity, insulin resistance, hypertension, and dyslipidemia, can cause muscle changes, oxidative stress (OS), and extracellular matrix (ECM) disorganization, with functional impairments. Physical exercise is indicated as a treatment; however, the most effective modality remains to be defined. Objective: To investigate the impact of two exercise modalities on the components of MS and their influence on skeletal muscle, evaluating OS biomarkers and ECM components. Methods: Wistar rats (n = 40) were distributed into two groups: control diet (C) or high-fat diet (MS) for 20 weeks. After characterization of MS, the animals were redistributed into four groups (n = 10): control (C), sedentary MS (MS), MS + resistance exercise (MS + RE) and MS + aerobic exercise (MS + AE), with an 8-week intervention, 5 days a week. RE: 50/75/90/100%, 4 climbs. AE: 80%8min+20%2min, 30–60 min. Food intake, weight gain, biochemical profile, functional capacity, OS markers: carbonylation, malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), and gene expression of ECM components (collagens and metalloproteinases) in the soleus and EDL muscles were evaluated. Statistical analysis used parametric tests: Student's t, ANOVA/Tukey, MANOVA/Bonferroni or nonparametric: Kruskal-Wallis/Dunn, (p<0.05). Results: MS was confirmed because it presented higher weight, blood glucose, blood pressure and triglycerides (p<0.05). MS reduced functional capacity and both exercise modalities improved physical performance between the pre- and post-training moments. The groups undergoing both types of training reduced weight, blood glucose, and blood pressure, while only aerobic exercise reduced % adiposity and triglycerides. The protocols reduced MDA and showed no change in carbonylation for both muscles evaluated. SOD levels increased in both exercise modalities in the soleus muscle, with no change in the EDL, and both muscles increased CAT only during resistance exercise. There were no changes in muscle gene expression. Conclusion: Both exercise modalities attenuated the effects of MS on muscles; aerobic exercise promoted greater benefits in functional capacity, and resistance exercise in redox balance for both muscles. Instituição: Universidade do Oeste Paulista Tipo do documento: Dissertação