To address the question whether ExoU, a Pseudomonas aeruginosa cytotoxin with phospholipase A₂ activity, can induce hemostatic abnormalities during the course of pneumosepsis, mice were instilled i.t. with the ExoU-producing PA103 P. aeruginosa or with a mutant obtained by deletion of the exoU gene. Control animals were instilled with sterile vehicle. To assess the role of ExoU in animal survival, mice were evaluated for 72 h. In all the other experiments, animals were studied at 24 h after infection. PA103-infected mice showed significantly higher mortality rate, lower blood leukocyte concentration, and higher platelet concentration and hematocrit than animals infected with the bacterial mutant, as well as evidences of increased vascular permeability and plasma leakage, which were confirmed by our finding of higher protein concentration in bronchoalveolar lavage fluids and by the Evans blue dye assay. Platelets from PA103-infected mice demonstrated features of activation, assessed by the flow cytometric detection of higher percentage of P-selectin expression and of platelet-derived microparticles as well as by the enzyme immunoassay detection of increased thromboxane A₂ concentration in animal plasma. Histopathology of lung and kidney sections from PA103-infected mice exhibited evidences of thrombus formation that were not detected in sections of animals from the other groups. Our results demonstrate the ability of ExoU to induce vascular hyperpermeability, platelet activation, and thrombus formation during P. aeruginosa pneumosepsis, and we speculate that this ability may contribute to the reported poor outcome of patients with severe infection by ExoU-producing P. aeruginosa.

This study examined the incorporation of cricket (Acheta domesticus) flour (CF) (0, control; 5.0%, CF5.0; 7.5%, CF7.5; and 10.0%, CF10.0) as a lean meat replacer in beef patties and its impact on composition, microbiological, sensory, and technological properties, as well as its influence on the cooking process. The inclusion of CF led to beef patties with significantly higher protein levels than the control group. Additionally, an elevation in total viable (TVC) and lactic acid bacteria (LAB) counts was observed. However, Enterobacteriaceae counts remained at safe levels. CF5.0 demonstrated similar sensory scores and purchase intention to the control treatment. CF7.5 and CF10.0 showed comparable sensory scores to the control except for texture attributes. The inclusion of CF significantly reduced cooking loss and diameter reduction values. Beef patties with CF were notably firmer and had a browner color than the control. In general, the cooking process impacted the technological properties similarly in both the control and beef patties with CF. In all cooked samples, no significant differences in pH, redness (a*), or texture were observed. This study demonstrated that incorporating up to 5.0% CF into beef patties is optimal in terms of composition, technological, sensorial, and cooking properties.

General cheese manufacturing involves high temperatures, fermentation and ripening steps that function as hurdles to microbial growth. On the other hand, the application of several different formulations and manufacturing techniques may create a bacterial protective environment. In cheese, the persistent behavior of Shiga toxin-producing Escherichia coli (STEC) relies on complex mechanisms that enable bacteria to respond to stressful conditions found in cheese matrix. In this review, we discuss how STEC manages to survive to high and low temperatures, hyperosmotic conditions, exposure to weak organic acids, and pH decreasing related to cheese manufacturing, the cheese matrix itself and storage. Moreover, we discuss how these stress responses interact with each other by enhancing adaptation and consequently, the persistence of STEC in cheese. Further, we show how virulence genes eae and tir are affected by stress response mechanisms, increasing either cell adherence or virulence factors production, which leads to a selection of more resistant and virulent pathogens in the cheese industry, leading to a public health issue.

Resumo A piometra é uma enfermidade endotelial que acomete com mais frequência as fêmeas adultas e ativas reprodutivamente. Caracteriza-se por inflamação e acúmulo de exsudato na cavidade uterina que geralmente está associada a infecções bacterianas. O presente estudo objetivou avaliar o perfil de resistência de isolados de Escherichia coli a partir do conteúdo uterino de 42 fêmeas caninas, atendidas no Setor de Cirurgia de Pequenos Animais do Hospital de Medicina Veterinária da Universidade Federal da Bahia, com diagnóstico de piometra. Para a realização da análise bacteriológica, uma amostra do conteúdo uterino foi obtida imediatamente após o ato cirúrgico de ovariosalpingohisterectomia terapêutica (OSH) e encaminhada para o laboratório. Após análise microbiológica observou-se uma predominância da bactéria Escherichia coli em 40,5% (15/37). As cepas de Escherichia coli isoladas apresentaram os maiores índices de resistência aos antimicrobianos eritromicina (93,3%), azitromicina (80%), ampicilina, amoxacilina e cefalotina (40% cada). Tal estudo reforça a necessidade da realização do exame microbiológico com finalidade epidemiológica e correta aplicação terapêutica, evitando, com isso, a utilização indiscriminada de antimicrobianos e potencial surgimento de estirpes multirresistentes.