Crosstalk between trace elements and T-cell immunity during early-life health in pigs

With gradual ban on the use of antibiotics, the deficiency and excessive use of trace elements in intestinal health is gaining attention. In mammals, trace elements are essential for the development of the immune system, specifically T-cell proliferation, and differentiation. However, there remain significant gaps in our understanding of the effects of certain trace elements on T-cell immune phenotypes and functions in pigs. In this review, we summarize the specificity, development, subpopulations, and responses to pathogens of porcine T cells and the effects of functional trace elements (e.g., iron, copper, zinc, and selenium) on intestinal T-cell immunity during early-life health in pigs. Furthermore, we discuss the current trends of research on the crosstalk mechanisms between trace elements and T-cell immunity. The present review expands our knowledge of the association between trace elements and T-cell immunity and provides an opportunity to utilize the metabolism of trace elements as a target to treat various diseases.

Are biters sick? Health status of tail biters in comparison to control pigs

BACKGROUND

Tail biting is a multifactorial problem. As the health status is one of the factors commonly linked to tail biting, this study focuses on the health of identified biters. 30 (obsessive) biters are compared to 30 control animals by clinical and pathological examination as well as blood and cerebrospinal fluid samples. In that way, altogether 174 variables are compared between the groups. Moreover, connections between the variables are analysed.

RESULTS

In the clinical examination, 6 biters, but only 2 controls (P = 0.019) were noticeably agitated in the evaluation of general behaviour, while 8 controls were noticeably calmer (2 biters, P = 0.02). Biters had a lower body weight (P = 0.0007) and 13 biters had overlong bristles (4 controls, P = 0.008). In the pathological examination, 5 biters, but none of the controls had a hyperceratosis or inflammation of the pars proventricularis of the stomach (P = 0.018). However, 7 controls and only 3 biters were affected by gut inflammation (P = 0.03). In the blood sample, protein and albumin levels were below normal range for biters (protein: 51.6 g/l, albumin: 25.4 g/l), but not for controls (protein: 53.7 g/l, albumin: 27.4 g/l), (protein: P = 0.05, albumin: P = 0.02). Moreover, 14 biters, but only 8 controls had poikilocytosis (P = 0.05). Although not statistically different between groups, many animals (36/60) were affected by hypoproteinemia and hyponatremia as well as by hypokalemia (53/60) and almost all animals (58/60) had hypomagnesemia. For hypomagnesemia, significant connections with variables linked to tail damage and ear necrosis were detected (r_s/V/ρ ≥ 0.4, P ≤ 0.05).

CONCLUSION

The results suggest that behavioural tests might be helpful in identifying biters. Moreover, cornification and inflammation of the pars proventricularis is linked to becoming a biter. Furthermore, the results highlight the need for appropriate and adjusted nutrient and mineral supply, especially with regard to magnesium.

Comorbidities and concentration of trace elements in livers of European bison from Bieszczady Mountains (Poland)

European bison is a species for which health monitoring is essential in conservation activities. So far, little research has been carried out on the concentration of elements in this species. Most previous studies did not associate the concentration of elements with susceptibility to diseases. In this study we investigate the relationship between comorbidities in European bison and concentrations of a wide spectrum of elements in the liver. Samples were collected during the monitoring of the European bison population in Bieszczady (southeast Poland) over the 2020-2022 period. Each individual was also visually inspected by a veterinarian in the field for the presence of lesions as a part of a post-mortem examination. The animals were divided into 3 groups: group A-one type of clinical sign; group B-two types of clinical signs; group C-three or more types of clinical signs. The ICP-OES method was applied to assess the concentration of 40 elements in livers. Discriminant analysis showed clear differences between the mineral status of individuals in the groups with one, two, and at least three types of clinical signs. Detailed analysis of selected elements showed that, in the case of eight elements, there was a relationship with age, sex, or comorbidities. Cu, Se, and Zn showed significant differences in relation to comorbidities, but only Cu concentration was lower when the frequency of lesions was higher. We concluded that in research on the mineral status of the population, apart from the availability of trace elements in the environment, the health condition of the studied individuals should also be considered. However, inferring the mineral status of the population on the basis of randomly obtained samples from dead individuals may give an incomplete view of the population, especially in the case of species susceptible to diseases, such as European bison.

Relationship between Plasma Zinc and Red Blood Cell Zinc Levels in Hospitalized Patients

Background

Patient zinc stores are quantified with plasma or red blood cell (RBC) measures. The relationship between these 2 measures of zinc status has not been determined in a broad population of hospitalized patients.

Methods

Both plasma zinc and RBC zinc were prospectively collected and measured in 252 consenting patients admitted urgently to hospital. Plasma and RBC zinc levels were measured within 48 h of admission. We collected demographic, vitals, and laboratory data for use in multivariate regression models that included markers of acute disease severity and systemic inflammation.

Results

Plasma zinc and RBC zinc levels were low in 63% and 10% of hospitalized patients, respectively. Categorized zinc levels based on normal intervals for plasma and RBC zinc values were not related (χ2 0.47 [2 df] P = 0.79). The Pearson correlation coefficient between plasma zinc and RBC zinc was −0.09 (P = 0.15). After adjustments for multiple clinical covariates, the correlation coefficient remained insignificant (r = −0.11, P = 0.08). Plasma zinc was inversely associated with markers of inflammation including the neutrophil-to-lymphocyte ratio and temperature.

Conclusions

Patient-specific plasma and RBC zinc are unrelated in hospitalized patients, possibly due to decreased values with acute illness seen in the former but not the latter. Future studies are required to determine which of these measures best predicts outcomes in hospitalized patients.

A multi-herd study shows that saliva is more than a reflection of serum biomarkers in pigs

This study evaluates if biomarkers of porcine health status in saliva samples is a mere reflection of serum to detect disease in pigs under field conditions. Four farms from the same commercial company were included to obtain samples from animals with different pathological conditions. A total of 10 healthy animals and 10-15 animals from each farm with clinical symptoms of the disease were sampled for paired saliva and blood during a veterinary clinical visit. The biomarker panel included acute-phase proteins (APPs), C-reactive protein (CRP), haptoglobin (Hp), an inflammatory marker, adenosine deaminase (ADA), the total antioxidant capacity (TAC), the levels of essential trace elements, copper (Cu) and zinc (Zn), and the measurement of the total protein content (TP). After detailed statistical analysis, the results showed that saliva could replace serum for APP measurements since a good agreement has been observed between the concentrations of APPs in both body fluids. For any other biomarker, no agreement between the concentrations quantified in serum and saliva samples was observed visually. However, salivary ADA and TP concentrations were statistically significantly higher in the diseased, whereas the statistical tests with serum concentrations were inconclusive. Furthermore, greater differentiation between healthy and diseased animals could be observed when the distribution of biomarkers was analysed in saliva than in other serum samples. The diagnostic power to discriminate between healthy and diseased pigs is similar in saliva and in serum samples. Preliminary regression models may offer an optimal combination of biomarkers for disease detection in saliva (Hp, CRP, and TAC) and serum (Hp, CRP, and Cu), which demands less labour, sample, and financial cost for saliva determinations. The contradictory results observed for TAC, Cu, and Zn levels between body fluids indicate a need for further studies. To sum up, saliva-based biomarkers instead of serum-based biomarkers could contribute to more efficient detection of diseased animals.

Potential of crocodile blood as a medication and dietary supplement: A systemic review

Crocodile blood has long been used as a traditional medicine in many Asian countries to treat diseases such as asthma, allergies, and many others. Yet, only recently has the safety and effectiveness of using crocodile blood as a medicine been examined using modern scientific methods; with both conserved and novel active components identified from crocodile blood. Further in vitro and in vivo investigations found that crocodile blood can have a wide range of beneficial effects, including antimicrobial, antiviral, anti-oxidative, anti-inflammatory, antitumour effects, anti-anaemia, and enhancement of wound healing. A systematic research of literature published in English-language journals up to April 2020 was conducted in PubMed, Google Scholar, and Web of Science. Based on the biological and chemical knowledge of crocodile immunity and crocodile blood, this article aims to: provide a critical review on the proposed properties of crocodile blood, identify the knowledge gap and offer some insights for future investigations regarding the use of crocodile blood as a medication or dietary supplement.

The Combined Effect of Weaning Stress and Immune Activation during Pig Gestation on Serum Cytokine and Analyte Concentrations

Weaning stress can elicit changes in the metabolic, hormone and immune systems of pigs and interact with prolonged disruptions stemming from maternal immune activation (MIA) during gestation. The present study advances the characterization of the combined effects of weaning stress and MIA on blood chemistry, immune and hormone indicators that inform on the health of pigs. Three-week-old female and male offspring of control gilts or gilts infected with the porcine reproductive and respiratory syndrome virus were allocated to weaned or nursed groups. The anion gap and bilirubin profiles suggest that MIA enhances tolerance to the effects of weaning stress. Interleukin 1 beta and interleukin 2 were highest among weaned MIA females, and cortisol was higher among weaned relative to nursed pigs across sexes. Canonical discriminant analysis demonstrated that weaned and nursed pigs have distinct chemistry profiles, whereas MIA and control pigs have distinct cytokine profiles. The results from this study can guide management practices that recognize the effects of the interaction between MIA and weaning stress on the performance and health of pigs.

Application of the MISTEACHING(S) disease susceptibility framework to Actinobacillus pleuropneumoniae to identify research gaps: an exemplar of a veterinary pathogen

Historically, the MISTEACHING (microbiome, immunity, sex, temperature, environment, age, chance, history, inoculum, nutrition, genetics) framework to describe the outcome of host-pathogen interaction, has been applied to human pathogens. Here, we show, using Actinobacillus pleuropneumoniae as an exemplar, that the MISTEACHING framework can be applied to a strict veterinary pathogen, enabling the identification of major research gaps, the formulation of hypotheses whose study will lead to a greater understanding of pathogenic mechanisms, and/or improved prevention/therapeutic measures. We also suggest that the MISTEACHING framework should be extended with the inclusion of a 'strain' category, to become MISTEACHINGS. We conclude that the MISTEACHINGS framework can be applied to veterinary pathogens, whether they be bacteria, fungi, viruses, or parasites, and hope to stimulate others to use it to identify research gaps and to formulate hypotheses worthy of study with their own pathogens.

Analytical characterization of trace elements (zinc, copper, cadmium, lead and selenium) in saliva of pigs under common pathological conditions in the field: a pilot study

Background

This study is focused on the measurement of trace elements (zinc, copper, cadmium, lead and selenium) in the saliva of pigs in order to study their levels on different porcine pathological conditions in the field. The experiment involved 15 pigs without clinical signs of disease and 42 diseased pigs (suffering from lameness, rectal prolapse, fatigue or growth rate retardation). Individual saliva samples were collected, allowing the pigs to chew a sponge each for trace element quantifications through atomic absorption spectrometry (AAS). Since this is the first report on the measurements of trace elements in porcine saliva, a routine analytical validation study was performed for the quantification of all the studied elements. Moreover, the acute phase proteins C-reactive protein (CRP) and haptoblobin (Hp), the total antioxidant capacity (TAC) and adenosine deaminase (ADA) were quantified in the saliva samples for the animal’s health status assessment.

Results

Modifications in the levels of acute phase proteins or ADA were only recorded in animals with lameness and rectal prolapse and those with fatigue respectively. Moreover, TAC level changes were observed in pigs with growth-rate retardation. However, alterations in the levels of two or more trace elements were reported for all the different groups of diseased pigs with evident variations within pathologies.

Conclusions

The salivary quantification of trace elements could be considered as a complementary tool to acute phase proteins, TAC and ADA determinations for disease detection and differentiation in the pig and should be explored in greater depth.

Low copper availability limits Helicobacter infection in mice

Copper is an essential element for all living organisms; however, it becomes toxic at high concentrations due to its ability to participate in many redox reactions. This vital micronutrient balance plays an important role in the battle between host and pathogen, due to its use by the host to intoxicate pathogens. In this study, we explore the effects of copper deprivation on Helicobacter infection in mice using the copper chelator tetrathiomolybdate. Our results reveal that Helicobacter infection significantly reduces copper concentration in mice stomachs without affecting its circulating levels. Moreover, in copper-deprived mice, bacteria hardly colonize the epithelium and mice show less gastric damage in comparison with the infected ones. However, when the copper chelator is administered after infection, the condition of the mouse stomachs declines. This could be explained by the lower copper availability in tetrathiomolybdate-treated mice, which would reduce macrophages' action against the pathogen. In this scenario, we observe that the protective factor trefoil factor 1 is induced upon copper-deprived conditions, probably contributing to the inefficacy of infection, whereas, when the chelator is administered after infection, the gene is already silenced by bacteria and cannot be restored. In conclusion, our data suggest that Helicobacter takes advantage of gastric copper reducing its availability for the host and that copper levels have an impact on the outcome of infection.

Haptoglobin and C-Reactive Protein-Non-specific Markers for Nursery Conditions in Swine

A quality concept for production in the pork market includes granting a good health status of pigs from birth to slaughter. This concept is a precondition for animal welfare as well as reducing antibiotic usage in farm animals. The demand for fighting bacterial antimicrobial resistance in humans, animals, and in the environment is one driving force for the development of innovative technical solutions to improve husbandry. Maintenance of a good health status in pigs depends on early detection of a disturbance in homeostasis in critical phases of life. This can be measured by non-specific biomarkers as acute phase proteins. In this project, husbandry conditions and health status in nursery pigs were monitored in an autumn and winter nursery period from weaning to the end of nursery in two compartments with 180 pigs each. It was investigated whether a slight modification in indoor climate achieved by a new ammonia sensory technology coupled with the electronic control unit of the forced ventilation system ensuring ammonia levels lower than 5 ± 3 ppm in one compartment led to a better health status in piglets in comparison to the control compartment. In the examined nursery periods in different seasons, ammonia concentrations in the experimental compartment were significantly lower than in the control compartment, thus proving the functionality and efficacy of the technical system. Production parameters as feed conversion rate and average daily weight gain were slightly improved in the experimental compartment without implementing other measures. Multifactorial analysis of variance resulted in a significant influence of season, daily quarter, and compartment on ammonia concentration. The challenge to preserve a high health status of piglets also during suboptimal outside climate in the transitional season was reflected by an increase in the acute-phase proteins haptoglobin (Hp) and C-reactive protein (CRP) in autumn compared to winter. The seasonal influence on concentrations of CRP and Hp superimposed potential influences of the climate modification. New technological concepts to reduce noxious gases and dust in the animal environment as well as emissions, which in parallel guarantee optimal temperatures also during extreme weather conditions, can be evaluated by clinical data in combination with biomarkers.

Effects of dietary sodium selenite and organic selenium sources on immune and inflammatory responses and selenium deposition in growing pigs

The study was conducted to compare effects of different dietary Se sources (sodium selenite [NaSe], Se-enriched yeast [Se yeast] or L-selenomethionine [SeMet]) and one Se-deficient control diet on the expression of selected genes, hematological and clinical biochemical parameters, and muscle morphology in two parallel trials with finisher pigs. Se concentrations in blood plasma and tissues were also monitored. From the pigs in one of the parallel groups, muscle samples obtained from Musculus longissimus dorsi (LD) before and during the trial were examined. The pigs in the other parallel group were challenged once with lipopolysaccharide (LPS) intravenously. Transcriptional analyses of LD showed that selenogenes SelenoW and H were higher expressed in pigs fed Se-supplemented diets compared with control. Furthermore, the expression of interferon gamma and cyclooxygenase 2 was lower in the Se-supplemented pigs versus control. In whole blood samples prior to LPS, SelenoN, SelenoS and thioredoxin reductase 1 were higher expressed in pigs fed NaSe supplemented feed compared with the other groups, possibly indicating a higher level of oxidative stress. After LPS exposure glutathione peroxidase 1 and SelenoN were more reduced in pigs fed NaSe compared with pigs fed organic Se. Products of most above-mentioned genes are intertwined with the oxidant-antioxidant system. No significant effects of Se-source were found on hematologic parameters or microscopic anatomy. The Se-concentrations in various skeletal muscles and heart muscle were significantly different between the groups, with highest concentrations in pigs fed SeMet, followed by those fed Se yeast, NaSe, and control diet. Consistent with previous reports our results indicate that dietary Se at adequate levels can support the body's antioxidant system. Our results indicate that muscle fibers of pigs fed organic Se are less vulnerable to oxidative stress compared with the other groups.

The influence of selenium and selenoproteins on immune responses of poultry and pigs

Selenium is an essential nutrient for poultry and pigs, and is important for a number of physiological processes including regulation and function of the immune system. Through its incorporation into selenoproteins, Se is involved in the regulation of oxidative stress, redox mechanisms, and other crucial cellular processes involved in innate and adaptive immune response. This review provides current knowledge on the mechanisms by which selenium can modulate the resilience to infectious diseases, and how this micronutrient can influence the capacity of the bird or the pig to maintain its productivity during an infectious challenge. In relation to the most frequent and economically important infectious diseases in poultry and pig production, the present paper considers the influence of different selenium sources (organic vs. inorganic Se) as well as dietary concentrations on the immune responses of poultry and pigs with major emphasis on the potential beneficial impact on animal resilience to common infectious diseases.

Update on Actinobacillus pleuropneumoniae-knowledge, gaps and challenges

Porcine pleuropneumonia, caused by the bacterial porcine respiratory tract pathogen Actinobacillus pleuropneumoniae, leads to high economic losses in affected swine herds in most countries of the world. Pigs affected by peracute and acute disease suffer from severe respiratory distress with high lethality. The agent was first described in 1957 and, since then, knowledge about the pathogen itself, and its interactions with the host, has increased continuously. This is, in part, due to the fact that experimental infections can be studied in the natural host. However, the fact that most commercial pigs are colonized by this pathogen has hampered the applicability of knowledge gained under experimental conditions. In addition, several factors are involved in development of disease, and these have often been studied individually. In a DISCONTOOLS initiative, members from science, industry and clinics exchanged their expertise and empirical observations and identified the major gaps in knowledge. This review sums up published results and expert opinions, within the fields of pathogenesis, epidemiology, transmission, immune response to infection, as well as the main means of prevention, detection and control. The gaps that still remain to be filled are highlighted, and present as well as future challenges in the control of this disease are addressed.

Role of essential trace elements in tuberculosis infection: A review article

Malnutrition is one of the risk factors in tuberculosis (TB) infection. Mineral levels perturbation is seen in patients with TB. Moreover there are some strategies to starve pathogens of essential metals. Here we decided to conclude association between some essential elements and TB. Copper, calcium and iron are essential for hosts' immune system although calcium and iron are necessary for Mycobacterium tuberculosis vitality. Changing these elements alongside with anti-TB therapy is suggested for better treatment outcomes.

Role of divalent metals in infectious disease susceptibility and outcome

BACKGROUND

Divalent metals play important roles in maintaining metabolism and cellular growth of both eukaryotic hosts and invading microbes. Both metal deficiency and overload can result in abnormal cellular function or damage. Given its central role in host-pathogen interactions, subtle alterations of divalent metal homeostasis can occur in the course of infectious diseases which aim, from the host perspective, either to reduce the availability of respective metals to microbes or to use toxic metal accumulation to eliminate pathogens.

AIMS

To provide the reader with background information and clinical data on divalent metal homeostasis in host-pathogen interactions, how this affects the course of infectious disease and whether correction of metal disturbances has shown benefit in infections.

SOURCES

An in-depth analysis of PubMed articles related to the topic of this review published in English between 1970 and 2016 was performed.

CONTENT

From the microbial perspective, divalent metals are essential for growth and pathogenicity and to mount effective protection against antimicrobial host responses, including toxic radical formation. Microbes have evolved multiple strategies to control their access to divalent metals. From the clinical perspective, alterations of divalent metal levels may result in increased or decreased susceptibility to infection and often occur in response to infections. However, keeping in mind the strategies underlying such alterations, for which the term 'nutritional immunity' was coined, the uncritical correction of such divalent metal imbalances may cause harm to patients. This review addresses the role of the divalent metals iron, selenium, zinc, manganese and copper in infectious diseases from a mechanistic and clinical perspective.

IMPLICATIONS

We point out areas of research needed to expand our limited knowledge, hoping to improve the clinical management of patients with infections and to identify promising new targets for treatment by modulation of host or microbe divalent metal metabolism.

Selenium, copper and iron in veterinary medicine-From clinical implications to scientific models

Diseases related to copper, selenium or iron overload or deficiency are common and well-described in large animal veterinary medicine. Some of them certainly have the potential to serve as useful animal models for ongoing research in the field of trace elements. Obvious advantages of large animal models compared to laboratory animal models like rats and mice are the option of long-term, consecutive examinations of progressive deficient or toxic stages and the opportunity to collect various, high volume samples for repeated measurements. Nevertheless, close cooperation between scientific disciplines is necessary as scientists using high sophisticated analytical methods and equipment are not regularly in touch with scientists working with large animal diseases. This review will give an introduction into some typical animal diseases related to trace elements and will present approaches where the animal diseases were used already as a model for interdisciplinary research.