Modelling severe Staphylococcus aureus sepsis in conscious pigs: are implications for animal welfare justified?

Background: A porcine model of haematogenous Staphylococcus aureus sepsis has previously been established in our research group. In these studies, pigs developed severe sepsis including liver dysfunction during a 48 h study period. As pigs were awake during the study, animal welfare was challenged by the severity of induced disease, which in some cases necessitated humane euthanasia.

Enteral but not parenteral antibiotics enhance gut function and prevent necrotizing enterocolitis in formula-fed newborn preterm pigs.

Preterm infants are susceptible to infection and necrotizing enterocolitis (NEC) and are often treated with antibiotics. Simultaneous administration of enteral and parenteral antibiotics during the first days after preterm birth prevents formula-induced NEC lesions in pigs, but it is unknown which administration route is most effective. We hypothesized that only enteral antibiotics suppress gut bacterial colonization and NEC progression in formula-fed preterm pigs.

Oral antibiotics increase blood neutrophil maturation and reduce bacteremia and necrotizing enterocolitis in the immediate postnatal period of preterm pigs.

Immature immunity may predispose preterm neonates to infections and necrotizing enterocolitis (NEC). Intravenous antibiotics are frequently given to prevent and treat sepsis, while oral antibiotics are seldom used. We hypothesized that oral antibiotics promote maturation of systemic immunity and delay gut bacterial colonization and thereby protect preterm neonates against both NEC and bacteremia in the immediate postnatal period.

Diet-induced dyslipidemia leads to nonalcoholic fatty liver disease and oxidative stress in guinea pigs.

Chronic dyslipidemia imposed by a high-fat and high-caloric dietary regime leads to debilitating disorders such as obesity, nonalcoholic fatty liver disease (NAFLD), and insulin resistance. As disease rates surge, so does the need for high validity animal models to effectively study the causal relationship between diet and disease progression. The dyslipidemic guinea pig displays a high similarity with the human lipoprotein profile and may in this aspect be superior to other rodent models.

Maternal vitamin C deficiency during pregnancy results in transient fetal and placental growth retardation in guinea pigs.

Purpose: Recently, we reported that preferential maternal-fetal vitamin C (vitC) transport across the placenta is likely to be impaired by prolonged maternal vitC deficiency. Maintenance of a basal maternal vitC supply at the expense of the fetus may impair fetal development; however, the knowledge of vitC's impact on intrauterine development is sparse. The aim of this study was to explore the effect of maternal vitC status on fetal and placental development in guinea pigs.

Non-terminal blood sampling techniques in guinea pigs.

Guinea pigs possess several biological similarities to humans and are validated experimental animal models(1-3). However, the use of guinea pigs currently represents a relatively narrow area of research and descriptive data on specific methodology is correspondingly scarce. The anatomical features of guinea pigs are slightly different from other rodent models, hence modulation of sampling techniques to accommodate for species-specific differences, e.

High fat, low carbohydrate diet limit fear and aggression in Göttingen minipigs.

High fat, low carbohydrate diets have become popular, as short-term studies show that such diets are effective for reducing body weight, and lowering the risk of diabetes and cardiovascular disease. There is growing evidence from both humans and other animals that diet affects behaviour and intake of fat has been linked, positively and negatively, with traits such as exploration, social interaction, anxiety and fear. Animal models with high translational value can help provide relevant and important information in elucidating potential effects of high fat, low carbohydrate diets on human behaviour.

Functional network analysis of obese and lean Göttingen minipigs elucidates changes in oxidative and inflammatory networks in obese pigs.

The Göttingen minipig model of obesity is used in pre-clinical research to predict clinical outcome of new treatments for metabolic diseases. However, treatment effects often remain unnoticed when using single parameter statistical comparisons due to the small numbers of animals giving rise to large variation and insufficient statistical power. The purpose of this study was to perform a correlation matrix analysis of multiple multi-scale parameters describing co-segregation of traits in order to identify differences between lean and obese minipigs.

Laparoscopic Roux-en-Y gastric bypass in super obese Göttingen minipigs.

Background: The specific mechanisms behind weight loss and comorbidity improvements in obese patients after Roux-en-Y gastric bypass (RYGBP) are still poorly understood. The aim of this study was to establish and evaluate the feasibility of a long-term survival RYGBP model in super obese Göttingen minipigs in order to improve the translational potential relative to current animal models.

Methods: Eleven Göttingen minipigs with diet-induced obesity underwent laparoscopic RYGBP and were followed up to 9 months after surgery.

Endothelial cell death and intimal foam cell accumulation in the coronary artery of infected hypercholesterolemic minipigs.

Apoptosis of endothelial cells (ECs) has been suggested to play a role in atherosclerosis. We studied the synergism of hypercholesterolemia with Chlamydia pneumoniae and influenza virus infections on EC morphology and intimal changes in a minipig model. The coronary artery was excised at euthanasia (19 weeks of age) and serial sections were processed for the detection of EC apoptosis, histology, and transmission electron microscopy (TEM) studies.

The use of sequential organ failure assessment parameters in an awake porcine model of severe Staphylococcus aureus sepsis.

The human sequential organ failure assessment (SOFA) scoring system is used worldwide in intensive care units for assessing the extent of organ dysfunction/failure in patients with severe sepsis. An increasing number of septic cases are caused by Gram-positive bacteria as Staphylococcus aureus. The aim of the current study was to apply the human SOFA parameters in an awake, porcine model of severe S.

Infection-induced coronary dysfunction and systemic inflammation in piglets are dampened in hypercholesterolemic milieu.

The synergism of infection with conventional cardiovascular risk factors in atherosclerosis is much debated. We hypothesized that coronary arterial injury correlates with infection recurrence and pathogen burden and is further aggravated by hypercholesterolemia. Forty-two Göttingen minipigs were assigned to repeated intratracheal inoculation of PBS, Chlamydia pneumoniae (Cpn), or both Cpn and influenza virus at 8, 11, and 14 wk of age.

High dietary fat and cholesterol exacerbates chronic vitamin C deficiency in guinea pigs.

Vitamin C deficiency - or hypovitaminosis C defined as a plasma concentration below 23 μm - is estimated to affect hundreds of millions of people in the Western world, in particular subpopulations of low socio-economic status that tend to eat diets of poor nutritional value. Recent studies by us have shown that vitamin C deficiency may result in impaired brain development. Thus, the aim of the present study was to investigate if a poor diet high in fat and cholesterol affects the vitamin C status of guinea pigs kept on either sufficient or deficient levels of dietary ascorbate (Asc) for up to 6 months with particular emphasis on the brain.

Expression studies of the obesity candidate gene FTO in pig.

Obesity is an increasing problem worldwide and research on candidate genes in good animal models is highly needed. The pig is an excellent model as its metabolism, organ size, and eating habits resemble that of humans. The present study is focused on the characterization of the fat mass and obesity associated gene (FTO) in pig.

Distribution of mast cells in relation to Schistosoma japonicum induced lesions in pigs.

The pathogenesis of schistosomiasis japonica has been extensively studied, however only little attention has been paid to the presence and localization of mast cells in relation to Schistosoma japonicum induced lesions. The aim of the present pilot study was to assess the parasitological and pathological responses in S. japonicum infected pigs with emphasis on the description of the distribution of mast cells in relation to lesions in the liver and cecum.