Corneal reshaping: an experiment with a type I collagen-based vitrigel for remodeling porcine corneas / Remodelamento corneano: relato de um experimento com um vitrigel a base de colágeno tipo I para remodelamento de córneas porcinas

ABSTRACT Purpose: This study aimed to report an experiment designed to determine anatomical changes in porcine corneas following placement of a novel polymer implant into the cornea. Methods: An ex vivo porcine eye model was used. A novel type I collagen-based vitrigel implant (6 mm in diameter) was shaped with an excimer laser on the posterior surface to create three planoconcave shapes. Implants were inserted into a manually dissected stromal pocket at a depth of approximately 200 μm. Three treatment groups were defined: group A (n=3), maximal ablation depth 70 μm; Group B (n=3), maximal ablation depth 64 μm; and group C (n=3), maximal ablation depth 104 μm, with a central hole. A control group (D, n=3) was included, in which a stromal pocket was created but biomaterial was not inserted. Eyes were evaluated by optical coherence tomography (OCT) and corneal tomography. Results: Corneal tomography showed a trend for a decreased mean keratometry in all four groups. Optical coherence tomography showed corneas with implants placed within the anterior stroma and visible flattening, whereas the corneas in the control group did not qualitatively change shape. Conclusions: The novel planoconcave biomaterial implant described herein could reshape the cornea in an ex vivo model, resulting in the flattening of the cornea. Further studies are needed using in vivo animal models to confirm such findings.

RESUMO Objetivo: Relatar um experimento projetado para determinar alterações anatômicas em córneas porcinas após a colocação de um novo implante de polímero na córnea. Métodos: Foi utilizado olho de porco ex vivo. Um novo agente modelador biocompatível, de colágeno tipo 1, com 6mm de diâmetro foi moldado com excimer laser em sua face posterior, para criar três formatos planocôncavos. Os implantes foram inseridos dentro de um bolsão, dissecado manualmente, a 200 micrômetros (μm). Foram definidos três grupos de tratamento: grupo A (n=3), teve a profundidade máxima de ablação de 70 μm; o grupo B (n=3), profundidade máxima de ablação de 64 μm; e o grupo C (n=3), profundidade máxima de ablação de 104 μm, com buraco central. O grupo controle, D (n=3), foi incluído, com a criação do bolsão estromal, porém sem inserir o material. A avaliação desses olhos foi realizada por tomografia de coerência óptica (OCT) e por tomografia corneana. Resultados: A tomografia corneana mostrou uma tendência para diminuição da ceratometria média em todos os 4 grupos. A tomografia de coerência óptica mostrou córneas com implantes localizados no estroma anterior e aplanamento visível, enquanto as córneas não mudaram qualitativamente o formato no grupo controle. Conclusões: O novo implante de biomaterial planocôncavo descrito aqui foi capaz de remodelar a córnea em modelo de animal ex vivo, resultando no aplanamento corneano. Novos estudos são necessários usando modelos animais in vivo para confirmar tais achados.

Can Saccharomyces cerevisiae supplementation improve piglets' performance and intestinal health after weaning? / A suplementação com Saccharomyces cerevisiae pode melhorar o desempenho e saúde intestinal de leitões após o desmame?

This study aimed to assess the impact of two commercial Saccharomyces cerevisiae strains (CHY1 and CHY2) on the intestinal health and performance of weaned piglets challenged with enterotoxigenic Escherichia coli during the nursery phase. One hundred ninety-two piglets with an average weight of 6.70 ± 0.92 kilograms were allocated in a randomized block design to one of four treatments: a negative control (C) without E. coli challenge and no yeast supplementation; a positive control (CH) with E. coli challenge and no yeast supplementation; and two treatment groups receiving an E. colichallenge with a CHY1 and CHY2 yeast strain supplementation. The challenge involved inoculating piglets with two dosages of E. coli F4 (106 CFU/ml and 109 CFU/ml) and a saline solution for the C group. Samples of intestinal tissue, blood, and cecal content were collected on the trial's 11th, 28th, and 42nd days. All variables were subjected to analysis of variance, and upon detecting significant differences via the F-test (p < 0.05), Tukey's test was applied to compare treatment means. For the analysis of diarrhea occurrence, the Kruskal-Wallis test was applied. When variables were rejected at a 5% probability level, a Dunn's test was conducted as a post-hoc analysis for paired multiple comparisons (p < 0.05), with statistical significance set at this level. Weaned piglets supplemented with CHY1 exhibited superior performance metrics, including higher average daily gain (15.3% increase), body weight (3.4% increase), feed-to-gain ratio (9.5% increase), and average daily feed intake (12.3% increase) at 28 days compared to the CH group across two different nutritional phases. No discernible effects were observed on measuring blood parameters, intestinal morphology, or cecal short-chain fatty acids. Both yeast-treated groups displayed improved performance during the most challenging periods. However, the CHY1 yeast strain contributed to enhanced piglet performance in the initial 28 days without inducing changes in intestinal morphology.(AU)

O presente estudo teve como objetivo avaliar duas cepas comerciais de Saccharomyces cerevisiae (designadas como CHY1 e CHY2) sob a saúde intestinal e desempenho de leitões desmamados desafiados com Escherichia coli enterotoxigênica durante a fase de creche. Um total de 192 leitões com peso médio 6,70 ± 0.92 quilogramas foram distribuídos em um delineamento em blocos casualizados com quatro tratamentos: um controle negativo (C) sem desafio de E. coli e sem suplementação da levedura; um controle positivo (CH) com desafio de E. coli e sem a suplementação da levedura; e dois grupos com a suplementação das dietas com as cepas comerciais das leveduras intituladas CHY1 e CHY2, juntamente ao desafio de E. coli. O desafio envolveu a inoculação de duas doses de E. coli F4 (106 UFC/ml e 109 UFC/ml) nos leitões e uma inoculação de solução salina para o grupo C. Amostras de tecido intestinal, sangue e conteúdo cecal foram coletadas nos 11º, 28º e 42º dias do experimento. Todas as variáveis foram submetidas a análise de variância e quando detectada diferença significativa pelo teste de F (p<0,05), o teste de Tukey foi aplicado para comparar as médias. Para a avalição da ocorrência de diarreia, o teste de Kruskal-Wallis foi aplicado e quando as variáveis foram rejeitadas ao nível de 5% de probabilidade, o teste de Dunn foi conduzido como uma análise post-hoc para comparações múltiplas (p<0,05) com significância estatística nesse nível. Leitões desmamados suplementados com CHY1 apresentaram métricas de desempenho superiores, incluindo maior ganho de peso diário (aumento de 15.3%), peso vivo (aumento de 3.4%), consumo de ração diário (aumento de 9.5%) e melhor eficiência alimentar (aumento de 12.3%) até os 28 dias de experimento em comparação com o grupo CH. Não foram observados efeitos dos tratamentos sobre os parâmetros sanguíneos mensurados, morfologia intestinal ou ácidos graxos de cadeia curta presentes no conteúdo cecal. Ambos os grupos tratados com leveduras apresentaram melhor desempenho durante os períodos mais desafiadores. No entanto, a cepa de levedura CHY1, especificamente, contribuiu para um melhor desempenho dos leitões nos primeiros 28 dias, sem induzir alterações na morfologia intestinal.(AU)

Acute and chronic changes in porcine rete mirabile after embolization with the Menox system: angiographic and histopathological analyses / Alterações angiográficas e histopatológicas agudas e crônicas da rete mirabile no modelo suíno com sistema embólico líquido Menox

Abstract Objective: To evaluate acute and chronic changes seen on angiographic and histopathological studies of porcine rete mirabile, comparing those treated with the Menox liquid embolic system (LES) and those treated with the Onyx LES. Materials and Methods: Five pigs, each weighing approximately 35 kg, were submitted to rete mirabile embolization under general anesthesia and fluoroscopic guidance, with the Menox LES or Onyx LES. Four animals were treated with the Menox LES and underwent cerebral angiography, followed by euthanasia, at 1, 30, 60, and 90 days after embolization. One animal was treated with the Onyx LES underwent the same procedures at 30 days after embolization. In a subsequent histopathological analysis, we compared the Menox LES and Onyx LES in terms of the acute and chronic changes observed. Results: We observed no significant changes in blood pressure, heart rate, or electrocardiographic parameters that could be attributed to the super-selective infusion of dimethyl sulfoxide or the Menox embolic agent. Fluoroscopy showed adequate material opacity, appropriate progression to the center of the rete mirabile and complete unilateral embolization. Microcatheters were uneventfully detached from the embolized nidus. We observed mild to moderate intravascular and extravascular inflammatory responses, without histological evidence of necrotizing arteritis. There were no adverse neurovascular events. Conclusion: The Menox LES appears to be safe and effective, as well as being apparently equivalent to the Onyx LES in terms of the postprocedure angiographic and histopathological findings.

Resumo Objetivo: Avaliar as alterações angiográficas e histopatológicas agudas e crônicas em rete mirabile suína tratadas com o Menox liquid embolic system (LES) e comparar essas alterações com a embolização com Onyx LES. Materiais e Métodos: A embolização da rete mirabile com Menox LES e Onyx LES foi realizada em cinco suínos pesando cerca de 35 kg sob anestesia geral e orientação fluoroscópica. Quatro animais tratados com Menox LES foram submetidos a angiografia cerebral seguida de eutanásia após 1, 30, 60 e 90 dias e um animal tratado com Onix LES foi submetido ao mesmo procedimento após 30 dias. A análise histopatológica subsequente para alterações agudas e crônicas avaliou o desempenho do Menox LES comparado ao Onyx LES. Resultados: Não foram observadas alterações significativas atribuíveis à infusão superseletiva de dimetilsulfóxido ou Menox nos parâmetros de pressão arterial, frequência cardíaca ou eletrocardiograma. A fluoroscopia mostrou opacidade adequada do material, progressão adequada para o centro da rete mirabile e embolização unilateral completa. Os microcateteres foram retirados do nidus embolizado sem complicações. Observou-se resposta inflamatória intravascular e extravascular leve a moderada, sem indício histológico de arterite necrosante. Nenhum dos casos apresentou eventos neurovasculares adversos. Conclusão: A injeção de Menox LES mostrou-se segura e eficaz, além de ser equivalente ao Onyx LES em relação aos achados angiográficos e histopatológicos pós-procedimento.

Condenações de carcaça suínas devido a doenças respiratórias revisão bibliográfica / Pork carcass condemnation due to respiratory diseases bibliographic review / Condena de canales de cerdo por enfermedades respiratorias revisión bibliográfica

As doenças respiratórias são um problema significativo na produção suína e podem levar à condenação de carcaças no abate. Entre os agentes causadores dessas doenças destacam-se o Actinobacillus pleuropneumoniae, Mycoplasma hyopneumoniae e a Pasteurella multocida. O Actinobacillus pleuropneumoniae é um patógeno altamente contagioso, que ocasiona hemorragia, pleuropneumonia purulenta e fibrosa. A Pleuropneumonia é amplamente distribuída e gera graves prejuízos para a suinocultura. O Mycoplasma hyopneumoniae ocasionador da pneumonia por micoplasma, doença respiratória crônica. As infecções originadas podem regular negativamente o sistema imunológico do hospedeiro e aumentar a infecção e assim a replicação de outros patógenos. A Pasteurella multocida é o agente causador de uma ampla gama de infecções levando a alto impacto econômico. Patógeno comensal e oportunista da boca, nasofaringe e trato respiratório superior. A identificação precoce e o manejo adequado desses agentes causadores de doenças respiratórias são fundamentais para minimizar a incidência de carcaças suínas. A adoção de medidas preventivas, como a vacinação e práticas de manejo adequadas, pode ajudar a prevenir a propagação dessas doenças e garantir a produção de carne suína segura e de alta qualidade para o consumo humano.(AU)

Respiratory diseases are a significant problem in pork production and can lead to condemnation of carcasses at slaughter. Among the causative agents of these diseases are Actinobacillus pleuropneumoniae, Mycoplasma hyopneumoniae and Pasteurella multocida. Actinobacillus pleuropneumoniae is a highly contagious pathogen that causes hemorrhage, purulent and fibrous pleuropneumonia. Pleuropneumonia is widely distributed and causes serious damage to pig farming. Mycoplasma hyopneumoniae causes mycoplasma pneumonia, a chronic respiratory disease. Originating infections can down-regulate the host's immune system and increase infection and thus replication of other pathogens. Pasteurella multocida is the causative agent of a wide range of infections leading to high economic impact. Commensal and opportunistic pathogen of the mouth, nasopharynx and upper respiratory tract. Early identification and proper management of these agents that cause respiratory diseases are essential to minimize the incidence of swine carcasses. Adopting preventive measures, such as vaccination and proper management practices, can help prevent the spread of these diseases and ensure the production of safe, high-quality pork for human consumption.(AU)

Las enfermedades respiratorias son un problema importante en la producción porcina y pueden provocar el decomiso de las canales en el matadero. Entre los agentes causantes de estas enfermedades se encuentran Actinobacillus pleuropneumoniae, Mycoplasma hyopneumoniae y Pasteurella multocida. Actinobacillus pleuropneumoniae es un patógeno altamente contagioso que causa hemorragia, pleuroneumonía purulenta y fibrosa. La pleuroneumonía está ampliamente distribuida y causa graves daños a la cría de cerdos. Mycoplasma hyopneumoniae causa neumonía por micoplasma, una enfermedad respiratoria crónica. Las infecciones que se originan pueden regular a la baja el sistema inmunitario del huésped y aumentar la infección y, por lo tanto, la replicación de otros patógenos. Pasteurella multocida es el agente causal de una amplia gama de infecciones que tienen un alto impacto económico. Patógeno comensal y oportunista de la boca, nasofaringe y tracto respiratorio superior. La identificación temprana y el manejo adecuado de estos agentes causantes de enfermedades respiratorias son fundamentales para minimizar la incidencia de las canales porcinas. La adopción de medidas preventivas, como la vacunación y prácticas de manejo adecuadas, puede ayudar a prevenir la propagación de estas enfermedades y garantizar la producción de carne de cerdo segura y de alta calidad para el consumo humano.(AU)

Impactos relacionados à qualidade da água na suinocultura: revisão de literatura / Impacts related to water quality in swine farming: literature review / Impactos relacionados con la calidad del agua en la cría porcina: revisión de la literatura

O emprego de água na suinocultura global é o principal insumo e, conse- quentemente, elevado. Mas, para que o produtor obtenha resultados positivos técnicos e econômicos, precisa controlar que a água tenha a qualidade correta e seja ministrada na quantidade certa, seguindo as indicações da Instrução Normativa nº 113/2020 do Minis- tério da Agricultura, Pecuária e Abastecimento-MAPA, acerca da qualidade exigida deste elemento líquido, bem como a Instrução Normativa nº 357/2005 do CONAMA, relacio- nada ao uso e controle da água potável destinada ao consumo de humanos e animais. Uma forma de manter a qualidade da água potável na suinocultura é utilizando o dióxido de cloro (ClO2), eficaz numa ampla faixa de pH (4-10) na eliminação de vírus, bactérias e algas. Neste trabalho, objetiva-se apresentar índices zootécnicos da suinocultura parana- ense relacionados com a qualidade da água potável ­ pH, alcalinidade, dureza e cloração - e o reflexo dela na sanidade do animal evitando a poluição dos efluentes. O procedi- mento metodológico adotado é qualitativo com abordagem indutiva e técnica de pesquisa exploratória baseada em uma revisão de literatura. Da pesquisa bibliográfico-documental em sites de revistas científicas como a UNIPAR, a SCIELO, a Biblioteca Digital de Teses e Dissertações (BDTD), e sites do MAPA obteve-se um vasto material de consulta e apoio acerca do tema apresentado. Conclui-se que a qualidade da água na suinocultura deve ser monitorada por um profissional para que a produção seja lucrativa, zelando pelo bem- estar do rebanho, oferecendo-lhes água potável devidamente tratada, evitando a cloração indevida, dureza e alcalinidade fora do padrão exigido por lei.(AU)

The use of water in world pig farming is the main input and, consequently, high. In order for the producer to obtain positive technical and economic results, he will need to control that the water has the correct quality and that it is administered in the appropriate quantity, following the indications of Regulatory Instruction No. 113/2020 of the Ministry of Agriculture, Livestock and Supply-MAPA, on the required quality of this liquid element, as well as CONAMA Normative Instruction No. 357/2005, relating to the use and control of drinking water for human and animal consumption. One way to maintain the quality of drinking water in pig farming is by using chlorine dioxide (ClO2), effective in a wide range of pH (4-10) to eliminate viruses, bacteria and algae. In this work, the objective is to present zootechnical indices of swine production in Paraná related to the quality of drinking water - pH, alkalinity, hardness and chlorination - and its reflection on animal health, avoiding effluent contamination. The methodological procedure adopted is qualitative with an inductive approach and an exploratory research technique based on a literature review. From the bibliographical-documentary research on websites of scientific journals such as UNIPAR, SCIELO, the Digital Library of Theses and Dissertations (BDTD) and MAPA websites, a large amount of reference and support material on the topic presented was obtained. It is concluded that the quality of water in pig farming must be monitored by a professional so that production is profitable, ensuring the well-being of the herd, offering them duly treated drinking water, avoiding undue chlorination, hardness and alkalinity of the appropriate standard required by law.(AU)

El uso de agua en la porcicultura mundial es el principal insumo y, en consecuencia, elevado. Para que el productor obtenga resultados técnicos y económicos positivos, necesitará controlar que el agua tenga la calidad correcta y se administre en la cantidad adecuada, siguiendo las indicaciones de la Instrucción Normativa nº 113/2020 del Ministerio de Agricultura, Pecuaria y Suministro-MAPA, sobre la calidad exigida de este elemento líquido, así como la Instrucción Normativa del CONAMA n° 357/2005, relativa al uso y control del agua potable destinada al consumo humano y animal. Una forma de mantener la calidad del agua potable en la porcicultura es utilizando el dióxido de cloro (ClO2), eficaz en una amplia faja de pH (4-10) para eliminar virus, bacterias y algas. En este trabajo, el objetivo es presentar índices zootécnicos de la producción porcina en Paraná relacionados con la calidad del agua de bebida - pH, alcalinidad, dureza y cloración - y su reflejo en la salud del animal, evitando la contaminación de los efluentes. El procedimiento metodológico adoptado es cualitativo con un enfoque inductivo y una técnica de investigación exploratoria basada en una revisión de la literatura. De la investigación bibliográfico-documental en sitios web de revistas científicas como UNIPAR, SCIELO, la Biblioteca Digital de Tesis y Disertaciones (BDTD) y sitios web del MAPA, se obtuvo una gran cantidad de material de consulta y apoyo sobre el tema presentado. Se concluye que la calidad del agua en la porcicultura debe ser monitoreada por un profesional para que la producción sea rentable, velando por el bienestar del hato, ofreciéndoles agua potable debidamente tratada, evitando cloraciones indebidas, durezas y alcalinidades del padrón adecuado exigido por ley.(AU)

Efficacy and safety evaluation of a novel domestic extracorporeal membrane oxygenation mainframe / 中华急诊医学杂志

Objective:To evaluate the safety and efficacy of a novel domestic extracorporeal membrane oxygenation (ECMO) mainframe in a porcine model, and to provide the basis for further clinical application.Methods:Five domestic healthy male white pigs, weighing (51±4) kg, were selected. The ECMO system was established by using a novel ECMO mainframe with imported membrane oxygenator and pipeline, and continued to run for 72 hours. ECMO parameters are as follows: veno-arterial ECMO, centrifugal pump speed 3 000-3 500 r/min, continuous infusion of heparin anticoagulation to maintain the activate clotting time (ACT) of 140-200 s. Real-time monitoring of speed, flow, pressure before pump, pressure after pump, pressure after membrane and other equipment parameters, and the equipment performance was scored. The changes of hemodynamics, blood lactic acid and blood routine were monitored dynamically. Repeated measures analysis of variance was used to compare different time points within the group. At the end of the experiment, the thrombosis in the pump head and oxygenator was observed. The animals were sacrificed to obtain the tissue samples of the main organs for gross observation and pathological injury evaluation.Results:All animals successfully ran the ECMO system for 72 hours. (1) The centrifugal pump speed should be maintained at 3 029-3 483 r/min, the flow rate was maintained at 2.24-2.60 L/min, The pressure before the pump between minus 107.57 and minus 31.86 mmHg, the pressure after the pump was 197.50-282.43 mmHg, and the pressure after the membrane was 178.71-261.5 mmHg, all were in the normal range, and there was no significant difference between different time points (all P>0.05). The performance scores of the mainframe were all 4 points or above, indicating that the use requirements were met. (2) The heart rate of the animals was 50-80 beats /min, the mean arterial pressure was 85-115 mmHg, and the lactic acid was 0.996-2.25 mmol/L, all within the normal range, and there was no significant difference between different time points (all P>0.05). The free hemoglobin was 8.98-16.39 mg/L, and the hemoglobin was 6.58-7.52 g/L, both within a reasonable range, and there was no significant difference between different time points (all P>0.05). The platelet count was 69.6-231.6×10 9/L, and showed a continuous downward trend ( P<0.05). ACT was maintained at 135-169 s, which was within the target range, and there was no significant difference between different time points ( P<0.05). (3) At the end of the experiment, there was no obvious thrombosis in the pump head and oxygenator, no obvious thrombosis or infarction in the heart, brain, liver, lung and kidney, and no obvious hemorrhage or necrosis under the microscope. Conclusions:The ECMO established by the novel domestic ECMO mainframe combined with imported membrane oxygenator and pipeline ran smoothly for 72 hours, achieving the target of effect and safety.

Micro flow imaging for diagnosing closed liver trauma in pigs / 中国医学影像技术

Objective To observe the value of micro flow imaging(MFI)for diagnosing closed liver trauma in pigs.Methods A self-made impactor was used to impact the liver of 15 healthy pigs under general anesthesia and establish pig models of closed liver trauma.Conventional ultrasound,MFI and contrast-enhanced ultrasound(CEUS)were used to observe the location,extent and degree of liver trauma.Afterwards,the pigs were executed and the livers were removed,and the liver lesions were observed.According gross pathological findings,the diagnostic efficacy of MFI was analyzed.Results Gross pathology showed a total of 29 liver traumas in 15 pigs.The accuracy rate of conventional ultrasound,MFI and CEUS for diagnosing liver trauma in pigs was 37.93％(11/29),82.76％(24/29)and 96.55％(28/29),respectively.Significant difference was found between conventional ultrasound and MFI,also between conventional ultrasound and CEUS(both P＜0.05),but not between MFI and CEUS(P＞0.05).MFI showed no obvious blood flow signal in more than half pig liver trauma sites,while showed"spring like"in 1 pig and scattered blood flow signals in 5 pigs.On CEUS,liver trauma sites in pigs present as low or no perfusion,while"jet like"contrast agent overflow from the liver was noticed in 1 pig and"spring like"contrast agent overflow in 5 pigs,forming liquid dark areas around the liver or in abdominal cavity.Conclusion MFI had certain value for diagnosing closed liver trauma in pigs,hence being comparable to CEUS.

The hemostatic effects of pelvic band with inflatable balloon in a swine model of hemodynamically unstable pelvic fracture / 中华创伤骨科杂志

Objective:To evaluate the hemostatic effects of our self-designed pelvic band with inflatable balloon in a swine model of hemodynamically unstable pelvic fracture.Methods:"Open-book like" fractures were created with the external iliac blood vessels exposed in 24 12-month-old female Bama miniature pigs which were randomly divided into 4 groups ( n=6). Group C (the control group) was subjected to no treatment other than exposure of the external iliac blood vessels, group D to no treatment following destruction of the external iliac blood vessels, group T1 to fixation with simple pelvic band after destruction of the external iliac blood vessels, and group T2 to fixation with our self-designed pelvic band with inflatable balloon after destruction of the external iliac blood vessels. The 4 groups were compared in terms of 40-min survival rate, bladder pressure, peak lactate value, total blood loss, bleeding rate, infusion rate, and angiographic images. Results:There was no significant difference in the baseline indexes among the 4 groups before experiment, showing comparability ( P>0.05). The 40-min survival rate in group T2 was 83.3% (5/6), significantly higher than that in groups D and T1 [0% (0/6) and 0% (0/6)] ( P<0.05). There were no significant differences among groups C, D, T1 and T2 in bladder pressure [(6.67±1.03) mmHg, (5.83±1.94) mmHg, (6.00±1.55) mmHg, and (6.00±1.10) mmHg] or in total blood loss among groups D, T1 and T2[(1,198.0±182.9) mL, (1,252.0±148.4) mL, and (1,150.0±125.7) mL] (all P>0.05). The peak lactate value in group T2 [(2.26±0.24) mmol/L] was significantly lower than that in group D [(5.00±0.60) mmol/L] and group T1 [(3.86±0.57) mmol/L], and the bleeding rate and infusion rate in group T2 [(25.83±5.49) mL/min and (26.00±4.69) mL/min] were also significantly lower than those in group D [(83.50±19.85) mL/min and (71.50±29.11) mL/min] and group T1 [(54.17±15.59) mL/min and (54.17±8.98) mL/min] (all P<0.05). Angiography showed contrast agent extravasation in group T2, especially from the artery, but the extravasation speed in group T2 was significantly slower than that in group D. Conclusion:In a swine model of hemodynamically unstable pelvic fracture, our self-designed pelvic band with inflatable balloon has a definite hemostatic effect on vascular injury which is better than that of a simple pelvic band.

Hemostatic effects of preperitoneal balloon tamponade with different volumes on hemodynamically unstable pelvic fracture-associated arterial and venous hemorrhage in a swine model / 中华创伤骨科杂志

Objective:To determine the effects of preperitoneal balloon (PPB) tamponade with different volumes of fluid on hemodynamically unstable pelvic fracture-associated arterial and venous hemorrhage in a swine model.Methods:A model of open-book pelvic fracture with injuries to external iliac vessels was established in 18 female 12-month old Bama miniature pigs. After the successful establishment of hemodynamically unstable pelvic fracture with vascular injury was confirmed by contrast agent imaging, the animals were randomized into 3 even groups ( n=6): a control group (group C) subjected to PPB tamponade with 0 mL fluid injected, group T1 subjected to PPB tamponade with 500-mL fluid injected, and group T2 subjected to PPB tamponade with 1,000-mL fluid injected. The 3 groups were compared in terms of 60-min survival rate, balloon pressure, peritoneal pressure, bladder pressure, 70-min survival rate, blood loss, and infusion volume. Results:There was no statistically significant difference in the basic hemodynamic or other experimental indicators among the 3 groups before experiment, indicating comparability ( P>0.05). The 60-min survival rate in group T2 was 100.0% (6/6), significantly higher than those in group C and group T1 [0.0% (0/6), 0.0% (0/6)] ( P<0.05). After fluid injection, the balloon pressure and preperitoneal pressure in group T2 were respectively (127.2±4.7) mmHg and (34.5±3.6) mmHg, significantly higher than those in group T1 [(78.7±3.8) mmHg and (13.7±2.8) mmHg] and in group C [0 mmHg and (9.0±1.4) mmHg], and the 2 indicators in group T1 were significantly higher than those in group C (all P<0.05). After fluid injection, there was no statistically significant difference among groups C, T1, and T2 in bladder pressure [(6.7±1.0) mmHg, (5.8±1.9) mmHg, and (6.0±1.1) mmHg] or in bleeding volume [(1,163.0±191.3) mL, (1,212.0±148.4) mL, and (975.0±133.2) mL] (all P≥ 0.05). The infusion volume in group T1 [(1,250.0±225.8) mL] was significantly larger than that in group C [(951.7±177.8) mL] ( P<0.05). No colorectal or bladder injuries were found by the anatomy of the experimental animals in 3 groups. Conclusions:PPB tamponade with 1,000-mL fluid injected in a swine model can efficiently control pelvic fracture-associated arterial and venous hemorrhage, and increase the 60-min survival rate with no colorectal or bladder injuries.

Study on the damage of primary branches of the Glisson system in the hepatic portal by argon plasma coagulation with different spraying time / 中华肝胆外科杂志

Objective:To investigate the effect of different spray-coagulation time of argon plasma coagulation (APC) injury on the Glisson system primary branche(G1) in the hepatic portal of pigs.Methods:Fifty clean healthy domestic pigs (27 females and 23 males, aged 7 to 14 months) were selected, with the body weighted (100.0±9.5) kg. They were randomly divided into five groups (A, B, C, D, and E), with 10 pigs in each group. G1 models were made and sprayed by APC for 1, 2, 3, 4, and 5 seconds. The damage, maximum damage area, maximum damage depth, and damage of the three branches of the Glisson system (the first branches of the portal vein, intrahepatic bile duct, and hepatic artery) were compared among the groups. The pigs were divided into two groups based on whether the three branches were damaged or not: the three-branch damage group ( n=23) and the control group ( n=27). The maximum damage area and maximum damage depth were compared between the two groups. Results:After the APC spraying, circular or elliptical damage appeared on the surface of the G1, with changes such as yellow-brown color, brown color, charred appearance, and defects. Under the microscope, G1 capsule was found to be deficient, the fibrous tissue beneath the capsule was ruptured, and the structures of small blood vessels and small bile ducts were incomplete. " Burn marks" and damage to the three branches of the Glisson system in G1 were also observed, and the damage was more severe at the center of the spray-coagulation. As the spray-coagulation time increased, the maximum damage area of the G1 model also increased, and the two were positively correlated ( r=0.90, P<0.001). The maximum damage depth was also positively correlated with spray-coagulation time ( r=0.97, P<0.001). The numbers of pigs with damage to the three branches of the Glisson system in Groups A-E were 0, 2, 5, 6, and 10, respectively, and the number of pigs with damage increased with the spray-coagulation time. In the three-branch damage group, the spray-coagulation time, maximum damage area, and maximum damage depth were all higher than those in the control group (without three-branch damage), and the differences were statistically significant (all P<0.05). Conclusion:The degree of damage to G1 caused by APC is positively correlated with the spray-coagulation time, and damage to the three branches of the Glisson system in G1 is related to the maximum damage area, maximum damage depth, and APC spray-coagulation time.

Ischemic stroke model in large animals / 国际脑血管病杂志

Due to the failure of multiple translational researches, Stroke Therapy Academic Industry Roundtable (STAIR) recommends the use of large animal models of focal cerebral ischemia for preclinical researches. Especially, stroke treatment has currently entered a new era of vascular recanalization. Large animals commonly used in acute ischemic stroke models include dogs, swine, sheep, and non-human primates, which can be used to simulate various aspects of cerebral ischemia and reperfusion (vascular recanalization) in patients. Although large animals have significant advantages due to their proximity to humans in anatomy and physiology, there are also issues with anatomical and physiological specificity and ethical limitations. This article summarizes the large animal ischemic stroke models prepared by craniotomy and endovascular intervention, hoping to help researchers select the most appropriate large animal ischemic stroke model, and then promote the development of stroke translational research.

Role and mechanism of tubastatin A in alleviating brain injury after cardiopulmonary resuscitation by inhibiting endoplasmic reticulum stress-mediated cell apoptosis in swine / 中华急诊医学杂志

Objective:To explore the role and mechanism of tubastatin A (TubA) in alleviating brain injury after cardiac arrest and cardiopulmonary resuscitation (CA-CPR) by inhibiting endoplasmic reticulum stress-mediated cell apoptosis in swine.Methods:Twenty-three conventional male white swine, weighing 33-40 kg, aged 4 to 6 months, were divided into 3 groups by random number table method: sham group ( n=6), CA-CPR group ( n=9), and TubA group ( n=8). The CA-CPR swine model was established by 9 min of electrically induced CA through pacing catheter in the right ventricle and then 6 min of CPR in the CA-CPR group. The CA-CPR swine model was established by the same method, and then a dose of 4.5 mg/kg of TubA at 5 min after resuscitation was intravenously infused in the TubA group. The serum concentrations of neuron specific enolase (NSE) and S100β protein (S100β) were measured using ELISA before modeling and at 1, 2, 4 and 24 h after resuscitation. Neurological deficit score (NDS) was evaluated at 24 h after resuscitation. Thereafter, the animals were euthanized, and brain cortex tissues were harvested, and the expression levels of caspase-12 and caspase-3 were measured using immunohistochemistry. Cell apoptosis index was detected by TUNEL assay. The variables among the three groups were compared with one-way analysis of variance and the Bonferroni hoc test using SPSS software. Results:Twenty-four h after resuscitation, the serum concentrations of NSE and S100β were significantly increased, and NDS was markedly elevated in the CA-CPR and TubA groups compared with the sham group (all P<0.05). Compared with the CA-CPR group, serum concentration of NSE starting 2 h after resuscitation and serum concentration of S100β starting 1 h after resuscitation were significantly decreased in the TubA group [NSE (ng/mL): (23.1±2.0) vs. (20.2±2.0) at 2 h, (28.4±2.3) vs. (23.7±1.9) at 4 h, (32.1±2.7) vs. (26.6±2.0) at 24 h; S100β (pg/mL): (2239±193) vs. (1923±101) at 1 h, (2817±157) vs. (2360±141) at 2 h, (3384±250) vs. (2691±210) at 4 h, (3965±303) vs. (3119±260) at 24 h, all P<0.05], and NDS was markedly reduced (240±30 vs. 63±44, P<0.05). At 24 h after resuscitation, brain cortex tissue detection showed that the expression levels of caspase-12 and caspase-3 were significantly increased, and cell apoptosis index was markedly elevated in the CA-CPR and TubA groups compared with the sham group (all P<0.05). However, the expression levels of caspase-12 and caspase-3 were significantly decreased [caspase-12:(7.1±0.7) vs. (4.2±0.4); caspase-3: (13.3±1.6) vs. (7.7±0.8), all P<0.05], and cell apoptosis index was markedly reduced in the TubA group compared to the CA-CPR group [(31.1±8.6) vs. (17.3±2.2), P<0.05]. Conclusions:TubA alleviates brain injury and neurological dysfunction after CA-CPR in swine, which may be related to the inhibition of cell apoptosis mediated by endoplasmic reticulum stress.

Screening and safety evaluation of heat-resistant protective agents for live classic swine fever vaccine / 中国生物制品学杂志

@#Objective To screen the formulation of heat-resistant protective agent for live classic swine fever(CSF) vaccine in order to prolong the preservation time of vaccine under harsh conditions.Methods The heat-resistant protective agent prepared based on the formula containing gelatin,D-sorbitol,trehalose,D casein hydrolysate of different contents was mixed with the live virus antigen of CSF and then lyophilized.The finished products with qualified appearance were screened for routine detection and aging resistance test,and the over-dose(10 and 30 portions) of the products qualified in the aging resistance test were used to immunize piglets via subauricular neck,5 for each to evaluate the safety of the vaccines.Results Among the 6 batches of lyophilized live CSF vaccine,3 batches(20200301,20200302 and 20200303) met the requirements of the current Chinese Veterinary Pharmacopoeia.The lyophilized loss was within 0.04～0.33 titers,and the moisture contents were all less than 2%;20200301 and 20200302 batches of finished products passed the aging resistance test.No adverse clinical symptoms were observed in all piglets 30 min after vaccination;The body temperatures of piglets vaccinated with 10 and 30 doses of vaccine were normal for 14 d after vaccination.Conclusion The two formulations of heatresistant protective agent selected might be used for freeze-dried preparations of live CSF vaccine with good effect of aging resistance and safety to piglets.

The I226R protein of African swine fever virus inhibits the cGAS-STING-mediated innate immune response / 生物工程学报

This study aimed to explore the mechanism of how African swine fever virus (ASFV) I226R protein inhibits the cGAS-STING signaling pathway. We observed that I226R protein (pI226R) significantly inhibited the cGAS-STING-mediated type Ⅰ interferons and the interferon-stimulated genes production by dual-luciferase reporter assay system and real-time quantitative PCR. The results of co-immunoprecipitation assay and confocal microscopy showed that pI226R interacted with cGAS. Furthermore, pI226R promoted cGAS degradation through autophagy-lysosome pathway. Moreover, we found that pI226R decreased the binding of cGAS to E3 ligase tripartite motif protein 56 (TRIM56), resulting in the weakened monoubiquitination of cGAS, thus inhibiting the activation of cGAS and cGAS-STING signaling. In conclusion, ASFV pI226R suppresses the antiviral innate immune response by antagonizing cGAS, which contributes to an in-depth understanding of the immune escape mechanism of ASFV and provides a theoretical basis for the development of vaccines.

Effect of SAM junctional tourniquet on respiration when applied in the axilla: A swine model / 中华创伤杂志(英文版)

PURPOSE@#SAM junctional tourniquet (SJT) has been applied to control junctional hemorrhage. However, there is limited information about its safety and efficacy when applied in the axilla. This study aims to investigate the effect of SJT on respiration when used in the axilla in a swine model.@*METHODS@#Eighteen male Yorkshire swines, aged 6-month-old and weighing 55 - 72 kg, were randomized into 3 groups, with 6 in each. An axillary hemorrhage model was established by cutting a 2 mm transverse incision in the axillary artery. Hemorrhagic shock was induced by exsanguinating through the left carotid artery to achieve a controlled volume reduction of 30% of total blood volume. Vascular blocking bands were used to temporarily control axillary hemorrhage before SJT was applied. In Group I, the swine spontaneously breathed, while SJT was applied for 2 h with a pressure of 210 mmHg. In Group II, the swine were mechanically ventilated, and SJT was applied for the same duration and pressure as Group I. In Group III, the swine spontaneously breathed, but the axillary hemorrhage was controlled using vascular blocking bands without SJT compression. The amount of free blood loss was calculated in the axillary wound during the 2 h of hemostasis by SJT application or vascular blocking bands. After then, a temporary vascular shunt was performed in the 3 groups to achieve resuscitation. Pathophysiologic state of each swine was monitored for 1 h with an infusion of 400 mL of autologous whole blood and 500 mL of lactated ringer solution. Tb and T0 represent the time points before and immediate after the 30% volume-controlled hemorrhagic shock, respectively. T30, T60, T90 and T120, denote 30, 60, 90, and 120 min after T0 (hemostasis period), while T150, and T180 denote 150 and 180 min after T0 (resuscitation period). The mean arterial pressure and heart rate were monitored through the right carotid artery catheter. Blood samples were collected at each time point for the analysis of blood gas, complete cell count, serum chemistry, standard coagulation tests, etc., and thromboelastography was conducted subsequently. Movement of the left hemidiaphragm was measured by ultrasonography at Tb and T0 to assess respiration. Data were presented as mean ± standard deviation and analyzed using repeated measures of two-way analysis of variance with pairwise comparisons adjusted using the Bonferroni method. All statistical analyses were processed using GraphPad Prism software.@*RESULTS@#Compared to Tb, a statistically significant increase in the left hemidiaphragm movement at T0 was observed in Groups I and II (both p < 0.001). In Group III, the left hemidiaphragm movement remained unchanged (p = 0.660). Compared to Group I, mechanical ventilation in Group II significantly alleviated the effect of SJT application on the left hemidiaphragm movement (p < 0.001). Blood pressure and heart rate rapidly increased at T0 in all three groups. Respiratory arrest suddenly occurred in Group I after T120, which required immediate manual respiratory assistance. PaO2 in Group I decreased significantly at T120, accompanied by an increase in PaCO2 (both p < 0.001 vs. Groups II and III). Other biochemical metabolic changes were similar among groups. However, in all 3 groups, lactate and potassium increased immediately after 1 min of resuscitation concurrent with a drop in pH. The swine in Group I exhibited the most severe hyperkalemia and metabolic acidosis. The coagulation function test did not show statistically significant differences among three groups at any time point. However, D-dimer levels showed a more than 16-fold increase from T120 to T180 in all groups.@*CONCLUSION@#In the swine model, SJT is effective in controlling axillary hemorrhage during both spontaneous breathing and mechanical ventilation. Mechanical ventilation is found to alleviate the restrictive effect of SJT on thoracic movement without affecting hemostatic efficiency. Therefore, mechanical ventilation could be necessary before SJT removal.

Use of organic acids to reduce Salmonella Typhimurium excretion in swine / Uso de ácidos orgânicos para reduzir a excreção de Salmonella Typhimurium em suínos

The use of antimicrobials as growth promoters and disease prevention is being constantly reduced in several animal production systems, including in the swine industry. Therefore, this study aimed to evaluate the effectiveness of using acidifiers to control Salmonella Typhimurium in 65-day-old pigs by detecting the pathogen in organs at euthanasia. For this, 24 piglets were divided into two experimental groups consisting of 12 piglets each. An untreated control group (G1) and a treatment group (G2) received a liquid organic acidifier in the drinking water for 10 days (D-5 to D5). Five days after the start of treatment (D0), all piglets were challenged with 106 CFU of Salmonella Typhimurium and assessed for 12 days (D12). Every three days (D3, D6, D9, and D12), three animals from each experimental group were euthanized and then submitted for necropsy. Samples from the intestines (ileum, cecum, mesenteric lymph nodes, and ileocolic lymph nodes), liver, spleen, and lungs were collected to isolate Salmonella. The results show that, numerically, Salmonella isolation in the organs of G2 was lower than in G1 and that the number of positive cecum samples in G1 (66.7%; 8/12) was statistically different from the number of positive models in G2 (16.7%; 2/12), with a reduction of 28.6% of the total cecum positive samples in the treated group compared to the control. Therefore, it was observed that the liquid organic acidifier product could reduce the colonization of organs by Salmonella Typhimurium. (AU)

Toxoplasma gondii infection in pig intended for human consumption: seroprevalence, risk factors and influence of biosecurity measures / Infecção por Toxoplasma gondii em suínos destinados ao consumo humano: soroprevalência, fatores de risco e influência de medidas de biosseguridade

Abstract A serologic and epidemiologic study was carried out in order to determinate herd and animal seroprevalence and associated factors for Toxoplasma gondii in commercial pigs from Espírito Santo state, Brazil. Blood samples were collected from 416 pigs from 55 producer farms in 27 municipalities. An indirect immunofluorescent assay (IFA) was performed to estimate the seroprevalence of T. gondii and identify the associated risk factors using a questionnaire. The T. gondii antibody prevalence rate in commercial swine herds was 15.4% (64/416) using a cutoff of 1:64. The seropositivity for T. gondii was related to the presence of cats, water origin and age of swine in the increase of seroprevalence, and the existence of internal isolation fences and use of composting chambers as protective factors. To the best of our knowledge, this is the first study to report anti- T. gondii antibodies in the serum of pigs in the state of Espírito Santo, Brazil. This finding is important to public health because seropositive pigs can harbor tissue cysts in their meat, thereby representing a zoonotic risk for consumers of raw or undercooked porcine meat or its products.

Resumo Um estudo sorológico e epidemiológico foi realizado com o objetivo de determinar a soroprevalência nas granjas e animais e também em fatores associados para Toxoplasma gondii em suínos comerciais do estado do Espírito Santo, Brasil. Foram coletadas amostras de sangue de 416 suínos de 55 granjas produtoras de 27 municípios. A reação de imunofluorescência indireta (RIFI) foi realizada com o uso de questionário, para estimar a soroprevalência do T. gondii e identificar os fatores de risco associados. A taxa de prevalência de anticorpos contra T. gondii, nos rebanhos comerciais de suínos, foi de 15,4% (64/416) com ponto de corte de 1:64. A soropositividade para T. gondii foi relacionada à presença de gatos, origem da água, a idade dos suínos no aumento da soroprevalência, a existência de cercas de isolamento interno e uso de câmaras de compostagem como fatores de proteção. De acordo com este estudo, ele é o primeiro a relatar anticorpos anti-T. gondii no soro de suínos no estado do Espírito Santo, Brasil. Este achado é importante para a saúde pública, pois suínos soropositivos podem abrigar cistos teciduais em suas carnes, representando um risco zoonótico para os consumidores de carne suína crua ou mal cozida ou seus produtos.

Sildenafil in endotoxin-induced pulmonary hypertension: an experimental study

Abstract Background Sepsis and septic shock still represent great challenges in critical care medicine. Sildenafil has been largely used in the treatment of pulmonary arterial hypertension, but its effects in sepsis are unknown. The aim of this study was to investigate the hypothesis that sildenafil can attenuate endotoxin-induced pulmonary hypertension in a porcine model of endotoxemia. Methods Twenty pigs were randomly assigned to Control group (n = 10), which received saline solution; or to Sildenafil group (n = 10), which received sildenafil orally (100 mg). After 30 minutes, both groups were submitted to endotoxemia with intravenous bacterial lipopolysaccharide endotoxin (LPS) infusion (4 µg.kg-1.h-1) for 180 minutes. We evaluated hemodynamic and oxygenation functions, and also lung histology and plasma cytokine (TNFα, IL-1β, IL6, and IL10) and troponin I response. Results Significant hemodynamic alterations were observed after 30 minutes of LPS continuous infusion, mainly in pulmonary arterial pressure (from Baseline 19 ± 2 mmHg to LPS30 52 ± 4 mmHg, p< 0.05). There was also a significant decrease in PaO2/FiO2 (from Baseline 411 ± 29 to LPS180 334 ± 49, p< 0.05). Pulmonary arterial pressure was significantly lower in the Sildenafil group (35 ± 4 mmHg at LPS30, p< 0.05). The Sildenafil group also presented lower values of systemic arterial pressure. Sildenafil maintained oxygenation with higher PaO2/FiO2 and lower oxygen extraction rate than Control group but had no effect on intrapulmonary shunt. All cytokines and troponin increased after LPS infusion in both groups similarly. Conclusion Sildenafil attenuated endotoxin-induced pulmonary hypertension preserving the correct heart function without improving lung lesions or inflammation.

Multidrug-resistant Salmonella spp. in fecal samples of pigs with suspected salmonellosis in Antioquia, Colombia, 2019-2021 / Salmonella spp. multirresistentes en muestras fecales de cerdos con presunta salmonelosis en Antioquia, Colombia, 2019-2021 / Salmonella spp. multirresistente em amostras fecais de suínos com suspeita de salmonelose em Antioquia, Colômbia, 2019-2021

ABSTRACT Objectives. To determine the proportion of Salmonella enterica in fecal samples of live pigs with suspected salmonellosis analyzed at the diagnostic unit of the University of Antioquia, Colombia between 2019 and 2021, and examine the serotypes and antimicrobial resistance patterns. Methods. This was a laboratory-based cross-sectional study of routine data on fecal samples received from pig farms in all nine subregions of Antioquia state, Colombia. Salmonella spp. detection at the university is done using enrichment, selective culture, and polymerase chain reaction. Serotypes were identified using the Kauffmann-White scheme and isolates were tested for antimicrobial susceptibility using broth microdilution. Results. Of 653 samples tested, 149 (23%) were positive for S. enterica. Nine serotypes were identified. The most common were Salmonella Typhimurium (56%) and its monophasic variant (35%). Resistance to ampicillin (70%) was most frequently observed, followed by ciprofloxacin (55%), and sulfamethoxazole-trimethoprim (52%). No isolates were resistant to amikacin and gentamicin. Multidrug resistance (resistance to ≥ 3 classes of antibiotics) was observed in 61 (44%) isolates. Multidrug resistance was highest in S. Typhimurium (57%) compared with the other serotypes. Serotype was associated with multidrug resistance (p = 0.01), but age of the pig and sub-region were not. Conclusions. The proportion of Salmonella spp. and the associated high levels of multidrug resistance are of concern and may indicate irrational use of antimicrobials and poor management practices in pig production systems in the region. Strengthened surveillance is needed to monitor and improve farm management practices and the use of antimicrobials in farms in Colombia.

RESUMEN Objetivos. Determinar la proporción de Salmonella enterica en muestras fecales de cerdos vivos con presunta salmonelosis analizadas en la unidad de diagnóstico de la Universidad de Antioquia (Colombia) entre el 2019 y el 2021, así como examinar los serotipos y los patrones de resistencia a los antimicrobianos. Métodos. Se trata de un estudio transversal de laboratorio sobre datos ordinarios de muestras fecales provenientes de granjas porcinas de las nueve subregiones del departamento de Antioquia (Colombia). La detección de Salmonella spp. en la universidad se realiza mediante el enriquecimiento, el cultivo selectivo y la reacción en cadena de la polimerasa. Se identificaron los serotipos con el esquema de Kauffmann-White y se examinaron las cepas aisladas para determinar la susceptibilidad antimicrobiana mediante microdilución en caldo. Resultados. De las 653 muestras analizadas, 149 (23%) dieron un resultado positivo para S. enterica. Se identificaron nueve serotipos. Los más comunes fueron Salmonella typhimurium (56%) y su variante monofásica (35%). La resistencia a la ampicilina fue la observada con mayor frecuencia (70%), seguida de la resistencia al ciprofloxacino (55%) y al sulfametoxazol-trimetoprima (52%). Ninguna cepa aislada fue resistente a la amikacina y la gentamicina. Se observó resistencia a múltiples fármacos (resistencia a tres o más clases de antibióticos) en 61 cepas (44%). La resistencia a múltiples fármacos fue más elevada en el caso de S. typhimurium (57%) en comparación con los otros serotipos. Se asoció el serotipo con la resistencia a múltiples fármacos (p = 0,01), a diferencia de la edad del cerdo y la subregión. Conclusiones. La proporción de Salmonella spp. y los elevados niveles asociados de resistencia a múltiples fármacos son preocupantes y pueden ser un indicativo de uso irracional de antimicrobianos y malas prácticas de gestión en los sistemas de producción porcina de la región. Es necesario reforzar la vigilancia para dar seguimiento y mejorar las prácticas de gestión agropecuaria y el uso de antimicrobianos en las granjas en Colombia.

RESUMO Objetivos. Determinar a proporção de Salmonella enterica em amostras de fezes de suínos vivos com suspeita de salmonelose analisadas na unidade de diagnóstico da Universidade de Antioquia, Colômbia, entre 2019 e 2021, e examinar seus sorotipos e padrões de resistência a antimicrobianos. Métodos. Estudo transversal, de base laboratorial, utilizando dados de rotina de amostras de fezes recebidas de suinocultores em todas as nove sub-regiões do estado de Antioquia, Colômbia. A detecção de Salmonella spp. na Universidade é feita por enriquecimento, cultura seletiva e reação em cadeia da polimerase. Os sorotipos foram identificados usando o esquema de Kauffmann-White, e os isolados foram testados quanto à suscetibilidade aos antimicrobianos pelo método de microdiluição em caldo. Resultados. Das 653 amostras testadas, 149 (23%) foram positivas para S. enterica. Foram identificados nove sorotipos. Os mais comuns foram Salmonella Typhimurium (56%) e sua variante monofásica (35%). A resistência à ampicilina (70%) foi observada com maior frequência, seguida pela resistência ao ciprofloxacino (55%) e ao sulfametoxazol/trimetoprima (52%). Nenhum isolado apresentou resistência à amicacina ou gentamicina. Multirresistência (resistência a ≥ 3 classes de antibióticos) foi observada em 61 isolados (44%). A multirresistência foi mais comum em S. Typhimurium (57%), em comparação aos outros sorotipos. Foi constatada associação da multirresistência com sorotipos (p = 0,01), mas não com idade do suíno ou sub-região. Conclusões. A proporção de Salmonella spp. e os níveis elevados associados de multirresistência a antimicrobianos aqui constatados são preocupantes, e podem indicar uso irracional de antimicrobianos e práticas inadequadas de manejo nos sistemas de suinocultura da região. É preciso fortalecer a vigilância para monitorar e melhorar as práticas de manejo agrícola e o uso de antimicrobianos em fazendas na Colômbia.

Use of organic acids to reduce Salmonella Typhimurium excretion in swine / Uso de ácidos orgânicos para reduzir a excreção de Salmonella Typhimurium em suínos

The use of antimicrobials as growth promoters and disease prevention is being constantly reduced in several animal production systems, including in the swine industry. Therefore, this study aimed to evaluate the effectiveness of using acidifiers to control Salmonella Typhimurium in 65-day-old pigs by detecting the pathogen in organs at euthanasia. For this, 24 piglets were divided into two experimental groups consisting of 12 piglets each. An untreated control group (G1) and a treatment group (G2) received a liquid organic acidifier in the drinking water for 10 days (D-5 to D5). Five days after the start of treatment (D0), all piglets were challenged with 106 CFU of Salmonella Typhimurium and assessed for 12 days (D12). Every three days (D3, D6, D9, and D12), three animals from each experimental group were euthanized and then submitted for necropsy. Samples from the intestines (ileum, cecum, mesenteric lymph nodes, and ileocolic lymph nodes), liver, spleen, and lungs were collected to isolate Salmonella. The results show that, numerically, Salmonellaisolation in the organs of G2 was lower than in G1 and that the number of positive cecum samples in G1 (66.7%; 8/12) was statistically different from the number of positive models in G2 (16.7%; 2/12), with a reduction of 28.6% of the total cecum positive samples in the treated group compared to the control. Therefore, it was observed that the liquid organic acidifier product could reduce the colonization of organs by Salmonella Typhimurium.(AU)

O uso de antimicrobianos como promotores de crescimento e prevenção de doenças vem sendo constantemente reduzido em diversos sistemas de produção animal, inclusive na suinocultura. Portanto, o objetivo do presente estudo foi avaliar a eficácia do uso de acidificantes no controle de Salmonella Typhimurium em suínos de 65 dias de idade, detectando o patógeno em órgãos após a eutanásia. Para isso, 24 leitões foram divididos em dois grupos experimentais constituídos por 12 leitões cada. Um grupo controle não tratado (G1) e um grupo de tratamento (G2) que recebeu um acidificante orgânico líquido na água de beber por 10 dias (D-5 a D5). Cinco dias após o início do tratamento (D0), todos os animais foram inoculados oralmente com 106 UFC de Salmonella Typhimurium e avaliados por 12 dias (D12). A cada três dias (D3, D6, D9 e D12), três leitões de cada grupo experimental foram eutanasiados e posteriormente submetidos à necropsia. Amostras de intestino (íleo, ceco, linfonodos mesentéricos e linfonodos ileocólicos), fígado, baço e pulmões foram coletadas para o isolamento de Salmonella. Os resultados mostram que, numericamente, o isolamento de Salmonella nos órgãos do G2 foi inferior ao G1, e que o número de amostras positivas de ceco no G1 (66,7%; 8/12) foi estatisticamente diferente do número de amostras positivas no G2 (16,7%; 2/12), com redução de 28,6% do total de amostras positivas de ceco no grupo tratado em relação ao controle. Portanto, observou-se que o ácido orgânico líquido foi capaz de reduzir a colonização de órgãos por Salmonella Typhimurium.(AU)