Toward establishing a rapid constant temperature detection method for canine parvovirus based on endonuclease activities.

Canine parvovirus (CPV) can cause high morbidity and mortality rates in puppies, posing a significant threat to both pet dogs and the breeding industry. Rapid, accurate, and convenient detection methods are important for the early intervention and treatment of canine parvovirus. In this study, we propose a visual CPV detection system called nucleic acid mismatch enzyme digestion (NMED). This system combines loop-mediated isothermal amplification (LAMP), endonuclease for gene mismatch detection, and colloidal gold lateral chromatography. We demonstrated that NMED can induce the binding of the amplicon from the sample to the specific labeling probe, which in turn triggers digestion by the endonuclease. The sensitivity and visual visibility of LAMP were increased by combining endonuclease and colloidal gold lateral chromatography assisted by a simple temperature-controlled device. The sensitivity of the NMED assay was 1 copy/µL, which was consistent with quantitative PCR (qPCR). The method was validated with 20 clinical samples that potentially had CPV infection; 15 positive samples and 5 negative samples were evaluated; and the detection accuracy was consistent with that of qPCR. As a rapid, accurate, and convenient molecular diagnostic method, NMED has great potential for application in the field of pathogenic microorganism detection. IMPORTANCE: The NMED method has been established in the laboratory and used for CPV detection. The method has several advantages, including simple sampling, high sensitivity, intuitive results, and no requirement for expensive equipment. The establishment of this method has commercial potential and offers a novel approach and concept for the future development of clinical detection of pathogenic microorganisms.

Gut microbiota contribution to selenium deficiency-induced gut-liver inflammation.

There is limited knowledge about the factors that drive gut-liver axis changes after selenium (Se) deficiency-induced gut or liver injuries. Thus, we tested Se deficiency in mice to determine its effects on intestinal bacterial balance and whether it induced liver injury. Serum Se concentration, lipopolysaccharide (LPS) level, and liver injury biomarkers were tested using a biochemical method, while pathological changes in the liver and jejunum were observed via hematoxylin and eosin stain, and a fluorescence spectrophotometer was used to evaluate intestinal permeability. Tight junction (TJ)-related and toll-like receptor (TLR) signaling-related pathway genes and proteins were tested using quantitative polymerase chain reaction, western blotting, immunohistochemistry, and 16S ribosomal ribonucleic acid gene-targeted sequencing of jejunum microorganisms. Se deficiency significantly decreased glutathione peroxidase activity and disrupted the intestinal flora, with the most significant effect being a decrease in Lactobacillus reuteri. The expression of TJ-related genes and proteins decreased significantly with increased treatment time, whereas supplementation with Se, fecal microbiota transplantation, or L. reuteri reversed these decreases. Signs of liver injury and LPS content were significantly increased after intestinal flora imbalance or jejunum injury, and the levels of TLR signaling-related genes were significantly increased. The results indicated that Se deficiency disrupted the microbiota balance, decreased the expression of intestinal TJ factors, and increased intestinal permeability. By contrast, LPS increased due to a bacterial imbalance, which may induce inflammatory liver injury via the TLR4 signaling pathway.

Selenium Deficiency via the ROS/NLRP3/IL-1ß Signaling Pathway Leads to Pyroptosis Injury in Pig Spleen.

The aim of the present study was to investigate the effect of selenium (Se) deficiency on the relationship between the pyroptosis and MAPK signaling pathway in spleen injury. A total of 10 two-month-old Sus scrofa domesticus specimens were allocated to two groups. The control group was fed a basal diet (0.15-mg/kg Se), and the experimental group was fed a 0.03-mg/kg Se-deficient diet for 2 months. The pig-spleen histopathological changes were observed with hematoxylin-eosin staining. Frozen sections were prepared to detect the content of ROS in pig-spleen cells. The oxidation stress related indexes were determined using a spectrophotometer. The levels of pyroptosis- and MAPK signaling pathway-related factors were detected via quantitative real-time polymerase chain reaction (qPCR) and western blotting (WB). The results of sections showed that the lymphocytes decreased in number, the spacing of cells widened, and some cells were necrotic in the spleen tissue of pigs fed a low-selenium diet. The content of ROS, malondialdehyde, nitric oxide, H2O2, and catalase activity in the low-selenium group was significantly higher than that in the control group, and SOD activity was decreased. The protein-ratio-levels of p-Nrf2 to Nrf2 were decreased. The expression levels of nod-like receptor (NLR) family pyrin domain containing 3 (NLRP3), IL-1ß, IL-18, ASC, gasdermin D, and caspase-1, the protein-ratio-levels of p-AKT serine/threonine kinase (p-AKT) to AKT, p-extracellular regulated protein kinases (ERK) to ERK, p-P38 MAPK to p-P38, and p-c-Jun N-terminal kinase (p-JNK) to JNK were significantly increased in the Se-deficient group compared with the control group. These results suggested that Se deficiency can induce oxidant stress, which increases pyroptosis- and inflammation-related factors of pig-spleen injury.

Meat Quality and Fatty Acid Profiles of Chinese Ningxiang Pigs Following Supplementation with N-Carbamylglutamate.

The present study evaluated the effects of dietary N-carbamylglutamate (NCG) on carcass traits, meat quality, and fatty acid profiles in the longissimus dorsi muscle and adipose tissues of Chinese Ningxiang pigs. A total of 36 castrated female pigs with a similar initial weight (43.21 ± 0.57 kg) were randomly assigned to two treatments (with six pens per treatment and three pigs per pen) and fed either a basal diet or a basal diet supplemented with 0.08% NCG for 56 days. Results showed that dietary NCG reduced shear force (p = 0.004) and increased drip loss (p = 0.044) in longissimus dorsi muscle of Ningxiang pigs. Moreover, increased levels of oleic acid (C18:1n9c) (p = 0.009), paullinic acid (C20:1) (p = 0.004), and α-linolenic acid (C18:3n3) (p < 0.001), while significant reduction in the proportions of arachidonic acid (C20:4n6) (p < 0.001) and polyunsaturated fatty acid (PUFA) (p = 0.017) were observed in the longissimus dorsi muscle of pigs fed NCG when compared with those fed the control diet. As for adipose tissues, the C20:1 (p = 0.045) proportion in dorsal subcutaneous adipose (DSA), as well as the stearic acid (C18:0) (p = 0.018) level in perirenal adipose (PA) were decreased when pigs were fed the NCG diet compared with those of the control diet. In contrast, the margaric acid (C17:0) (p = 0.043) proportion in PA were increased. Moreover, the NCG diet produced PA with a greater proportion of total PUFAs (p = 0.001) (particularly linoleic acid (C18:2n6c) (p = 0.001)) compared with those produced by the control diet. These findings suggest that dietary NCG has beneficial effects by decreasing the shear force and improving the healthfulness of fatty acid profiles, providing a novel strategy for enhancing meat quality of pigs.

Comparison of fatty acid profile of three adipose tissues in Ningxiang pigs.

The present study is conducted to determinate fatty acids (FA) composition in 3 adipose tissues. Subcutaneous and perirenal adipose tissues were prepared from 24 Ningxiang castrated boars and 24 castrated gilts fattened by a traditional diet for 56 d, respectively. The results showed that the FA profile in the 3 adipose tissues (dorsal subcutaneous adipose [DSA], abdominal subcutaneous adipose [ASA], and perirenal adipose [PA]) differed greatly. In boars, the proportions of oleic acid (c18:1n9c) (P < 0.05), cis-11-20c acid (c20:1) (P < 0.05), and α-linolenic acid (c18:3n3) (P < 0.05) in DSA were the highest among 3 adipose tissues, whereas palmitic acid (c16:0) (P < 0.05) and stearic acid (c18:0) (P < 0.05) in DSA had the lowest proportion. In gilts, cis-11-20c acid (c20:1) (P < 0.05) in DSA was the highest, while stearic acid (c18:0) (P < 0.05) in subcutaneous adipose was the lowest among these deposits. Overall, the results indicate that from external to inner carcass of boars, the sum of saturated fatty acids (SFA) increase, but the sum of monounsaturated fatty acids (MUFA) decrease, while ASA of gilts have the greatest proportion of MUFA and the lowest SFA. Sex and adipose locations as significant effects on the FA profile are interaction.

Effect of Soyabean Isoflavones Exposure on Onset of Puberty, Serum Hormone Concentration and Gene Expression in Hypothalamus, Pituitary Gland and Ovary of Female Bama Miniature Pigs.

This study was to investigate the effect of soyabean isoflavones (SIF) on onset of puberty, serum hormone concentration, and gene expression in hypothalamus, pituitary and ovary of female Bama miniature pigs. Fifty five, 35-days old pigs were randomly assigned into 5 treatment groups consisting of 11 pigs per treatment. Results showed that dietary supplementation of varying dosage (0, 250, 500, and 1,250 mg/kg) of SIF induced puberty delay of the pigs with the age of puberty of pigs fed basal diet supplemented with 1,250 mg/kg SIF was significantly higher (p<0.05) compared to control. Supplementation of SIF or estradiol valerate (EV) reduced (p<0.05) serum gonadotrophin releasing hormone and luteinizing hormone concentration, but increased follicle-stimulating hormone concentration in pigs at 4 months of age. The expression of KiSS-1 metastasis-suppressor (KISS1), steroidogenic acute regulatory protein (StAR) and 3-beta-hydroxysteroid dehydrogenase/delta-5-delta-4 isomerase (3ß-HSD) was reduced (p<0.01) in SIF-supplemented groups. Expression of gonadotropin-releasing hormone receptor in the pituitary of miniature pigs was reduced (p<0.05) compared to the control when exposed to 250, 1,250 mg/kg SIF and EV. Pigs on 250 mg/kg SIF and EV also showed reduced (p<0.05) expression of cytochrome P450 19A1 compared to the control. Our results indicated that dietary supplementation of SIF induced puberty delay, which may be due to down-regulation of key genes that play vital roles in the synthesis of steroid hormones.