Exosome-Based Vaccines: Pros and Cons in the World of Animal Health.

Due to the emergence of antibiotic resistance and new and more complex diseases that affect livestock animal health and food security, the control of epidemics has become a top priority worldwide. Vaccination represents the most important and cost-effective measure to control infectious diseases in animal health, but it represents only 23% of the total global animal health market, highlighting the need to develop new vaccines. A recent strategy in animal health vaccination is the use of extracellular vesicles (EVs), lipid bilayer nanovesicles produced by almost all living cells, including both prokaryotes and eukaryotes. EVs have been evaluated as a prominent source of viral antigens to elicit specific immune responses and to develop new vaccination platforms as viruses and EVs share biogenesis pathways. Preliminary trials with lymphocytic choriomeningitis virus infection (LCMV), porcine reproductive and respiratory syndrome virus (PRRSV), and Marek's disease virus (MDV) have demonstrated that EVs have a role in the activation of cellular and antibody immune responses. Moreover, in parasitic diseases such as Eimeria (chickens) and Plasmodium yoelii (mice) protection has been achieved. Research into EVs is therefore opening an opportunity for new strategies to overcome old problems affecting food security, animal health, and emerging diseases. Here, we review different conventional approaches for vaccine design and compare them with examples of EV-based vaccines that have already been tested in relation to animal health.

Body stalk anomalies in pig-Definition and classification.

The presence of body wall closing defects (abdominoschisis and thoracoabdominoschisis) in combination with other congenital malformations was studied in the pig (Sus scrofa domesticus). After clinical examination and literature review, body wall defects with multiple congenital anomalies in eight pigs were described, and classified using anatomical and embryological criteria. Several BSA presentations were identified and classified as follows: (a) BSA Type I: fetus with spinal and UC defects, thoracoabdominoschisis, anal atresia and/or other internal organs structural defects, and structural limb defects; (b) BSA Type II: fetus with spinal and UC defects, thoracoabdominoschisis, anal atresia and/or other internal organs structural defects, and nonstructural limb defects; (c) BSA Type III: fetus with spinal and UC defects, abdominoschisis, anal atresia and/or other internal organs structural defects, and structural limb defects; and (d) BSA Type IV: fetus with spinal and UC defects, abdominoschisis, anal atresia and/or other internal organs structural defects, and nonstructural limb defects. Two types of LBWC were differentiated: LBWC Type I: characterized by thoracoabdominoschisis and structural limb defects, and LBWC Type II: characterized by abdominoschisis and structural limb defects, corresponding to BSA type I and type III. This is the first report on BSA and LBWC in the pig.

Classification, bacteriological findings, and analysis of sex hormone receptors and cytokine expression in mammary lesions of abattoir sows.

Mammary lesions in sows can prevent suckling piglets from consuming colostrum that provides fundamental nutrients and protective immunity. Although mammary gross lesions are frequently found in sows at farms or slaughterhouses, with the exception of mastitis, they have received little research attention. In this study, we investigated mammary lesions observed in South Korean sows between 2015 and 2016. Mammary tissue samples of 82 sows showing gross lesions during meat inspection were histologically classified and immunohistochemical analysis was conducted to assess the expression of estrogen receptor (ER)-α, ER-ß, and progesterone receptor (PR) for mammary hyperplastic lesions as well as that of cluster of differentiation (CD) 3, CD79a, interleukin (IL)-1α, IL-1ß, IL-6, and IL-8 for mastitis. Furthermore, 20 swab samples were cultured, and the isolated bacteria were identified using polymerase chain reactions for 16S ribosomal RNA genes. The lesions were classified as hyperplasia, mastitis, or hyperplasia with mastitis. Immunohistochemistry results revealed that there was neither expression of ER-α nor of ER-ß, but all examined hyperplastic samples expressed PR. In addition, there was a significant correlation between CD3 and IL-1ß expressions, as well as between IL-1ß and IL-6 expressions. Regarding the identity of the isolated bacteria, Pseudomonas spp. were most frequently detected. The results of this study have revealed the incidence and characteristics of porcine mammary lesions.

Background Pathological Changes in Minipigs: A Comparison of the Incidence and Nature among Different Breeds and Populations of Minipigs.

Swine, especially the miniature swine or minipigs, are increasingly being used in preclinical safety assessment of small molecules, biopharmaceutical agents, and medical devices as an alternate nonrodent species. Although swine have been used extensively in biomedical research, there is a paucity of information in the current literature detailing the incidence of background lesions and differences in incidence between commonly used breeds. This article is a collaborative effort between multiple organizations to define and document lesions found in the common breeds of minipigs used for toxicological risk assessment in North America (NA) and the European Union (EU). We retrospectively assessed 10 years of historical control data from several institutions located in NA and EU, covering the period of 2004-2015. Here we report the background lesions with consideration of breed and geographical location. To our knowledge, this is the first report documenting spontaneous background lesions in commonly used breeds of swine in both NA and EU. This report serves as a resource to pathologists and will aid in interpretation of findings and differentiation of background from test article-related changes.

A survey of porcine picornaviruses and adenoviruses in fecal samples in Spain.

In the course of an epidemiologic surveillance program for swine diseases carried out in Spain, 206 cytopathic viruses were isolated from 600 porcine fecal samples between 2004 and 2005. The virus isolates were examined using reverse transcription polymerase chain reaction (RT-PCR) methods specific for different types of porcine picornaviruses, including members of the Teschovirus, Enterovirus, and Sapelovirus genera, and PCR for porcine adenoviruses. Of the 206 isolates, 97 (47%) were identified as teschoviruses, 18 (9%) as sapeloviruses, and 7 (3%) as porcine adenoviruses. Neither Porcine enterovirus B nor Swine vesicular disease virus was found among the isolates. The present study confirms that teschoviruses are highly prevalent in porcine fecal samples, at least in Spain. It also reveals that these viruses commonly circulate among apparently healthy pigs.

Wide variety of bioserotypes of enteropathogenic Yersinia in tonsils of English pigs at slaughter.

The tonsils of 630 pigs from 45 English farms using three different rearing methods (Assured British Pigs, Open Management and Organic) were examined between 2003 and 2005 in order to investigate if the low incidence of human yersiniosis could be attributed to a low prevalence of enteropathogenic Yersinia among English pigs. In addition, different isolation methods were compared, possible differences in prevalence among pigs were studied, as well as the prevalence of different bioserotypes of enteropathogenic Yersinia. A high prevalence and a wide diversity of bioserotypes of enteropathogenic Yersinia compared to other European countries were observed. The prevalence of pathogenic Yersinia enterocolitica was 44% and of Yersinia pseudotuberculosis 18%. Overall, 60% of pigs carried enteropathogenic Yersinia. Y. pseudotuberculosis was detected on 78% of farms and Y. enterocolitica on 69%. The most common bioserotypes of Y. enterocolitica were 2/O:9 (33%) and 2/O:5 (26%), and of Y. pseudotuberculosis 2/O:3 (34%), 1/O:1 (26%) and 1/O:4 (24%). Cold enrichment gave the highest isolation rate for both species. Y. enterocolitica was more prevalent (P<0.001) and Y. pseudotuberculosis less prevalent (P<0.05) in winter than in summer in Eastern England. Y. enterocolitica was more common in Eastern England and in assured British pigs, whereas Y. pseudotuberculosis was more common in Western England and in organic pigs. Y. pseudotuberculosis 1/O:1 was predominant (P<0.05) in Western England. Types 1/O:4 (P<0.05) and 2/O:3 (P<0.001) predominated in Eastern England. The high prevalence of Y. enterocolitica bioserotypes 2/O:9 and 2/O:5 found in this study suggests that English pigs are an important reservoir of these bioserotypes whereas in other European countries bioserotype 4/O:3 predominates.

Oesophagogastric ulceration in pigs: a visual morphological scoring guide.

OBJECTIVE: To provide a visual guide for oesophagogastric ulcer scoring and recognition of different morphological changes in the pars oesophagea. DESIGN: Pig stomachs were collected at slaughter and visually evaluated and scored for parakeratosis, erosion and ulceration in the pars oesophagea. RESULTS: A visual and descriptive guide is presented that will aid in the objective assessment and scoring of oesophagogastric ulceration in pigs within the pig health monitoring system (PHMS), namely to the four categories of 0 = normal stomach, 1 = parakeratosis and thickened epithelium, 2 = erosions and 3 = developed ulcers with and without stenosis. CONCLUSION: A visual guide has been developed that illustrates the full range of morphological changes that can occur in the pars oesophagea of the stomach within the few currently recognised stages of the disease.

Genetic variation and geographic distribution of porcine reproductive and respiratory syndrome virus in Japan.

Porcine reproductive and respiratory syndrome virus (PRRSV) has two genotypes, the North American-type (NA-type) and the European-type (EU-type), and each genotype is also genetically diverged. We sequenced the ORF5 gene of 30 PRRSVs isolated from 23 prefectures of Japan during 1992 and 1993 and during 2000 and 2001. All of the isolates were of the NA-type. Phylogenetic analysis of the overall NA-type viruses isolated from around the world identified five major genetic clusters. The 1992-1993 Japanese samples belonged to only two genetic clusters, while the 2000-2001 samples included more diverged ORF5 genomes. One genetic cluster, which included 63% (20/32) of Japanese isolates, one Taiwanese isolate and one Chinese isolate, was mainly found in the eastern part of Japan. Another genetic cluster, which was found in various areas around the world, was distributed in the western part of Japan.

[Occurrence of the fusariotoxins deoxynivalenol and zearalenone in Austrian feedstuff in the period from 1995 to 1999]. / Zum Vorkommen der Fusarientoxine Desoxynivalenol und Zearalenon in österreichischen Futtermitteln im Zeitraum von 1995 bis 1999.

3970 feed samples were analysed for the fusariumtoxins deoxynivalenol and zearalenone. 979 (24.6%) of the submitted feed samples from farms with case history (swine herds: decreased feed intake and daily weight gain, vomiting, cannibalism, impaired fertility, small litter size, weakness of newborn piglets, prolonged oestrus of sows; cattle: persistence of follicular ovarian cysts, enteritis, decreased slaughter weight, feed refusal). 74% of the samples contained cereal and corn ingredients respectively or were complete diet samples from swine herds. Based on economic losses the fusariumtoxin deoxynivalenol is most important in Austrian husbandry and particularly found in maize, cornsilage, wheat and oat.

Interactive classification of porcine Eimeria spp. by computer-assisted image analysis.

Digitalized pictures of oocysts of Eimeria scabra, E. polita, E. debliecki, E. suis, and E. porci were used to develop a program routine that allows semi-automatic interactive classification of porcine Eimeria spp. with a computer-assisted image analysis system. Morphological parameters (shape, color, length and width of oocysts and length and width of sporocysts) were assayed, transformed to color and shape factors and used to calculate classification indices (G1, SP). Thresholds were defined for these indices to allocate oocysts to groups of species and successively to single species. In more than 97% of cases the program routine allocated digitalized oocysts (n = 175) to the respective species. E. suis was always correctly classified. Interactive classification proved to be convenient, fast, precise and largely free of individual bias.

Statistical method for characterization of hypertrophic cardiomyopathy by use of morphologic and pathologic measurements in pigs (Sus scrofa domestica).

BACKGROUND AND PURPOSE: Hypertrophic cardiomyopathy (HCM) is characterized by symmetric or asymmetric hypertrophy of the left and/or right ventricle. Morphologic and pathologic indices (MI and PI) of hearts were established for classification of HCM in pigs. METHODS: Fifty on-farm-performance-tested pigs (average body weight, 104.3 kg; age, 224.5 days) were randomly selected. Heart weight, length, width, heart-to-body weight ratio, and thickness of the cranial and middle portions of ventricular septum and left ventricular free wall were measured. Myocyte disorganization and necrosis, myocardial and endocardial fibrosis, and intramural coronary arterial occlusion were scored. Principal component analysis and stepwise regression analysis were used to establish MI and PI. RESULTS: MI was established by using the first principal component as the dependent variable and applying stepwise regression analysis. Hearts were classified as morphologically normal, suspicious, and hypertrophic according to the range of MI. The same statistical method was used to find PI. Hearts were classified as pathologically normal, moderately affected, or seriously affected according to the range of PI. Combining MI and PI, hearts could be classified into five groups: no hypertrophy with minor lesion (normal); hypertrophy but with rare lesion; no hypertrophy but seriously affected; suspicious; and hypertrophy and seriously affected (heart with HCM). Another 119 hearts were collected and classified. The variation of heart measurements was consistent with the original purpose of classification. CONCLUSIONS: Using fewer measurements for identification of HCM objectively in pigs seems to have practical application.

Identificación de granjas seropositivas a Mycoplasma hyopneumonie y exploración de potenciales factores de riesgo relacionados a su presentación en 33 granjas porcinas del estado de Yucatan, México / To identify forms seropositive to mycoplasma hyopneumonie and to investigate the potential risk factors on its presentation in 33 pig farms in the state of Yucatan, Mexico

Introducción. Dentro de los problema infecciosos más graves que afectan a la porcicultura intensiva en todo el mundo se encuentran los respiratorios, los cuales producen efectos adversos sobre la ganancia de peso, la eficiencia alimenticia y la mortalidad. El objetivo del estudio fue detectar la presencia de anticuerpos contra Mycoplasma hyopneumonie (M. hyopneumonie) en cerdos de engorda del estado de Yucatán, México. Material y métodos. Se realizó un estudio transversal en 33 granjas porcinas del estado de Yucatán. En cada granja se recolectó 14 muestras de sueros procedentes de cerdos de engorda (= 5 meses de edad) de líneas comerciales. Para la detección de anticuerpos contra M. hyopneumonie, se utilizó una prueba comercial de ELISA indirecta. En cada granja se aplicó un cuestionario para conocer potenciales factores que pudieran estar relacionados a la seropositividad. La seroprevalencia de M. hyopneumoie se estratificó en dos categorías (ó 30 por ciento) y (> 30 por ciento) y se utilizó la prueba de Ji cuadrada para explorar la asociación con variables contenidas en aspectos generales, de instalaciones y equipo, medidas zoosanitarias y manejo. Resultados. De las 33 granjas muestreadas, 31 (93.9 por ciento) tuvieron al menos un animal seropositivo a M. hyopneumonie. De los 462 sueros evaluados, 168 (36.4 por ciento) resultaron seropositivos. No se encontró asociación (p>0.05) entre las variables analizadas como potenciales factores de riesgo y las seroprevalencias a M. hyopneumonie. Conclusioens. La seropositividad a M. hyopneumonie se encuentra presente y ampliamente distribuida en las granjas porcinas estudiadas y que éstas realizan práctica de manejo que pueden favorecer la presencia o incremento de la seroprevalencia a M. hyopneumonie

Epidemiological studies of pig diseases: 1. Use of French protocols for risk factor assessment to predict the health status of Australian herds.

OBJECTIVE: To determine in Australian pig herds the accuracy of French protocols for risk factor assessment. PROCEDURE: Data on health indicators and risk factors were collected for three syndromes, 'pre-weaning diarrhoea', 'post-weaning diarrhoea' and 'respiratory problems', using the French protocols. The protocols were used on 118 occasions in 32 Western Australian pig herds during 3 years (1988 to 1991). RESULTS: There was a wide variation in pre-weaning performance, for example growth rate was 107 to 273 g/day (< 200 g/day in 33% of herds). Respiratory lesions at weaning were associated with poor pre-weaning performance. Post-weaning (21 days after weaning) growth rate was 114 to 408 g/day (< 250 g/day in 54% of herds). In the grower herds, 91% of herds had pneumonia, and growth rate was 439 to 625 g/day (< 550 g/day in 54% of herds). Pleurisy as well as pneumonia was associated with reduced growth rate. The risk factor most closely associated with respiratory health status was air volume per pig. CONCLUSION: Risk factors were most accurate at predicting the health status in post-weaning problems. A weaning weight of at least 7.9 kg and weaning age of 30 days optimised weaner performance. Stocking densities and shed designs providing at least 3 m3 air volume and 0.6 m2 floor space per pig throughout the growing phase should be considered for an improved respiratory health status. Australian pig sheds often do not provide a satisfactory environment for optimum health. The technique of risk factor assessment as an aid to the maintenance of health in pig herds is applicable in Australia, but further research is necessary to determine the most important Australian risk factors.

Epidemiological studies of pig diseases: 2. Post-weaning diarrhoea and performance in Western Australian pigs.

OBJECTIVE: To determine in Australian pig herds the accuracy of French protocols for risk factor assessment of post-weaning diarrhoea and illthrift. PROCEDURE: French protocols for the collection of data on health indicators and risk factors for post-weaning diarrhoea were conducted on 54 batches of weaner pigs from 28 Western Australian pig herds during three years. RESULTS: Large variations in post-weaning performance were found. About one-third of the batches were growing at < 200 g/day during the 3 weeks after weaning, and 54% had growth rates of < 250 g/day. Weaning age and weight of at least 30 days and 7.9 kg, respectively, optimised weaner performance. Other risk factors associated with little post-weaning diarrhoea and good weaner performance were high creep feed intakes, relatively little diarrhoea as suckers, and, contrary to expectations, large temperature fluctuations. CONCLUSION: Overall, the 'predictability' of post-weaning problems as assessed by measurement of risk status, was good. However, the model was less accurate at predicting the performance of a single batch of pigs.