Engineered Bacillus subtilis alleviates intestinal oxidative injury through Nrf2-Keap1 pathway in enterotoxigenic Escherichia coli (ETEC) K88-infected piglet / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Engineered probiotics can serve as therapeutics based on their ability of produce recombinant immune-stimulating properties. In this study, we built the recombinant Bacillus subtilis WB800 expressing antimicrobial peptide KR32 (WB800-KR32) using genetic engineering methods and investigated its protective effects of nuclear factor-E2-related factor 2 (Nrf2)‍-Kelch-like ECH-associated protein 1 (Keap1) pathway activation in intestinal oxidative disturbance induced by enterotoxigenic Escherichia coli (ETEC) K88 in weaned piglets. Twenty-eight weaned piglets were randomly distributed into four treatment groups with seven replicates fed with a basal diet. The feed of the control group (CON) was infused with normal sterilized saline; meanwhile, the ETEC, ETEC+WB800, and ETEC+WB800-KR32 groups were orally administered normal sterilized saline, 5×1010 CFU (CFU: colony forming units) WB800, and 5×1010 CFU WB800-KR32, respectively, on Days 1‍‒‍14 and all infused with ETEC K88 1×1010 CFU on Days 15‍‒‍17. The results showed that pretreatment with WB800-KR32 attenuated ETEC-induced intestinal disturbance, improved the mucosal activity of antioxidant enzyme (catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx)) and decreased the content of malondialdehyde (MDA). More importantly, WB800-KR32 downregulated genes involved in antioxidant defense (GPx and SOD1). Interestingly, WB800-KR32 upregulated the protein expression of Nrf2 and downregulated the protein expression of Keap1 in the ileum. WB800-KR32 markedly changed the richness estimators (Ace and Chao) of gut microbiota and increased the abundance of Eubacterium_rectale_ATCC_33656 in the feces. The results suggested that WB800-KR32 may alleviate ETEC-induced intestinal oxidative injury through the Nrf2-Keap1 pathway, providing a new perspective for WB800-KR32 as potential therapeutics to regulate intestinal oxidative disturbance in ETEC K88 infection.

Rice bran oil supplementation protects swine weanlings against diarrhea and lipopolysaccharide challenge / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Early weaned piglets suffer from oxidative stress and enteral infection, which usually results in gut microbial dysbiosis, serve diarrhea, and even death. Rice bran oil (RBO), a polyphenol-enriched by-product of rice processing, has been shown to have antioxidant and anti-inflammatory properties both in vivo and in vitro. Here, we ascertained the proper RBO supplementation level, and subsequently determined its effects on lipopolysaccharide (LPS)-induced intestinal dysfunction in weaned piglets. A total of 168 piglets were randomly allocated into four groups of seven replicates (42 piglets each group, (21±1) d of age, body weight (7.60±0.04) kg, and half males and half females) and were given basal diet (Ctrl) or basal diet supplemented with 0.01% (mass fraction) RBO (RBO1), 0.02% RBO (RBO2), or 0.03% RBO (RBO3) for 21 d. Then, seven piglets from the Ctrl and the RBO were treated with LPS (100 μg/kg body weight (BW)) as LPS group and RBO+LPS group, respectively. Meanwhile, seven piglets from the Ctrl were treated with the saline vehicle (Ctrl group). Four hours later, all treated piglets were sacrificed for taking samples of plasma, jejunum tissues, and feces. The results showed that 0.02% was the optimal dose of dietary RBO supplementation based on diarrhea, average daily gain, and average daily feed intake indices in early weaning piglets. Furthermore, RBO protected piglets against LPS-induced jejunal epithelium damage, which was indicated by the increases in villus height, villus height/crypt depth ratio, and Claudin-1 levels, as well as a decreased level of jejunal epithelium apoptosis. RBO also improved the antioxidant ability of LPS-challenged piglets, which was indicated by the elevated concentrations of catalase and superoxide dismutase, and increased total antioxidant capacity, as well as the decreased concentrations of diamine oxidase and malondialdehyde in plasma. Meanwhile, RBO improved the immune function of LPS-challenged weaned piglets, which was indicated by elevated immunoglobulin A (IgA), IgM, β‍‍-defensin-1, and lysozyme levels in the plasma. In addition, RBO supplementation improved the LPS challenge-induced dysbiosis of gut microbiota. Particularly, the indices of antioxidant capacity, intestinal damage, and immunity were significantly associated with the RBO-regulated gut microbiota. These findings suggested that 0.02% RBO is a suitable dose to protect against LPS-induced intestinal damage, oxidative stress, and jejunal microbiota dysbiosis in early weaned piglets.

Effect of dihydroartemisinin supplementation on inflammation and lipid metabolism induced by lipopolysaccharide in liver of weaned piglets / 中国中药杂志

To study the effect of dihydroartemisinin(DHA) on hepatic inflammation and lipid metabolism in weaned piglets, a liver injury model of weaned piglets was established by lipopolysaccharide(LPS)-induced method. In this study, 30 healthy weaned piglets were selected and randomly divided into control group(CON), model group(LPS) and treatment group(LD, LPS+DHA), with 10 in each group. The CON group and the LPS group were fed with a basal diet, and the LD group was fed with a basal diet+80 mg·kg~(-1) DHA. The test period was 21 days. The LPS group and the LD group were intraperitoneally injected with 100 μg·kg~(-1) LPS at 4 hours before slaughter, and the CON group was injected with the same dose of sterile physiological saline. The results showed that compared with the CON group, contents of TC, AST activity and AST/ALT ratio were significantly increased in the serum of LPS piglets(P<0.05), content of HDL-c was significantly decreased(P<0.05). In addition, in the liver, the levels of TG, NEFA, IL-1β, IL-6 and TNF-α were increased significantly(P<0.05), and activities of LPL, HL and TL were decreased significantly(P<0.05). Compared with LPS group, content of TC, activities of AST and ALT and the AST/ALT ratio were decreased significantly(P<0.05), and HDL-c content increased significantly in the serum of LD piglets(P<0.05). The contents of TG, NEFA, IL-1β, IL-6 and TNF-α and activity of FAS in the liver were decreased significantly(P<0.05), and the activities of LPL, HL and TL were increased significantly(P<0.05). Compared with the CON group, the mRNA expressions of IL-1β, IL-6, TNF-α, ACCβ and SREBP-1 c in the LPS group were significantly increased(P<0.05), the mRNA expressions of AMPKα, SIRT1, CPT-1 and SCD were decreased significantly(P<0.05). The above indicators were improved in the LD group compared with the LPS group. These results indicated that DHA had a certain effect in recovering LPS-induced liver inflammation and abnormal lipid metabolism.

Prevalence of O-serogroups, virulence genes, and F18 antigenic variants in Escherichia coli isolated from weaned piglets with diarrhea in Korea during 2008–2016

To diagnose colibacillosis, detection of O-serogroups and virulence genes has been recommended worldwide. The prevalence of virulence factors can fluctuate over time. The objectives of this study were to determine the prevalence of O-serogroups, virulence genes, and F18 subtypes among pathogenic Escherichia coli isolated from weaned piglets with diarrhea in Korea. Between 2008 and 2016, 362 E. coli were isolated from weaned piglets with diarrhea. Hemolysis was determined in blood agar, and O-serogroups were identified using the slide agglutination technique. The genes for the toxins and fimbriae were amplified by polymerase chain reaction (PCR). Real-time PCR was conducted to discriminate between F18 subtypes. Although the most prevalent serogroup was O149 (11.3%) in the last 9 years, O139 (19.1%) became the most prevalent in recent years (2015–2016). The most predominant pathotype was enterotoxigenic E. coli (61.3%). The frequencies of Shiga-like toxin-producing E. coli (STEC) (23.4%), O139 (19.1%), Stx2e (35.1%), and F18ab (48.7%) increased over the most recent years. Although enterotoxigenic E. coli was the most predominant pathotype, the frequencies of O139, Stx2e, STEC, and F18ab have increased in recent years. These results demonstrate that there have been temporal changes in the predominant O-serogroups and virulence genes over the last decade in Korea. These findings can be practicable for use in epidemiology and control measures for enteric colibacillosis in Korean piggeries.

Evidence of bovine viral diarrhea virus transmission by back pond water in experimentally infected piglets / Evidência da transmissão do vírus da diarreia viral bovina através da lâmina d'água em leitões experimentalmente infectados

Swine can be infected by bovine viral diarrhea virus (BVDV). However, transmission routes among pigs are still unknown. The objective of the present study was to induce experimental infection of BVDV-1 in weaned piglets and to assess the potential transmission through pen back pond water, used to facilitate heat exchange of the pigs housed in barns. Two repetitions (BP1 and BP 2) were performed using 12 piglets proven to be free BVDV (n=6 per repetition) allocated into three groups: control, sentinels and infected with two piglets each. The piglets were placed in stainless steel isolators. The infected group received an inoculum containing BVDV-1, Singer strain. The piglets remained in the cabinets for 25 days, during which samples of nasal swab were collected daily and blood sampled weekly. At the end, the piglets were euthanized, necropsied and organ fragments were collected for histopathology, immunohistochemistry and RT-PCR. In the first experiment (BP1) the infected animals shed the virus between days 6 and 21 post-infection. Regarding the sentinel group, shedding occurred in only one piglet, on the 20th day after infection, and seroconversion was observed on the 25th day post-infection. In BP2, infected piglets I3 and I4 shed the virus on days 4 and 21 post-infection, respectively. Only one sentinel piglet (S3) she the virus on day 13 post-infection. Therefore, it was concluded that pigs can become infected with BVDV-1 and shed potentially infectious viral particles consequently, being able to transmit the virus to other pigs through back pond water.(AU)

Os suínos podem ser infectados pelo vírus da diarreia viral bovina (BVDV). No entanto, as vias de transmissão entre os suínos são ainda desconhecidas. O objetivo do presente estudo foi induzir a infecção experimental de BVDV-1 em leitões desmamados e avaliar a potencial transmissão pela lâmina d'água, que ajuda na troca de calor dos suínos alojados em baias. Duas repetições do experimento (BP1 e BP2) foram realizadas com 12 animais comprovadamente livres de BVDV (n=6 por repetição) alocados em três grupos: controle, sentinelas e infectados, com dois animais cada. Os animais foram mantidos em isoladores de aço inoxidável. O grupo infectado recebeu um inóculo contendo BVDV-1, estirpe Singer. Os animais permaneceram nos isoladores durante 25 dias e, durante esse período, amostras de suabe nasal foram coletadas diariamente e sangue coletado semanalmente. No final, os animais foram eutanasiados, necropsiados e fragmentos de órgãos foram coletados para histopatologia, imuno-histoquímica e RT-PCR. No primeiro experimento (BP1), os animais infectados excretaram partículas virais entre os dias 6 e 21 pós-infecção. Quanto ao grupo sentinela, a excreção ocorreu apenas em um animal, no 20º dia pós-infecção, e a soroconversão foi observada no 25º dia pós-infecção. Na BP2, os animais infectados I3 e I4 excretaram partículas virais nos dias 4 e 21 pós-infecção, respectivamente. Apenas um animal sentinela (S3) apresentou excreção no dia 13 pós-infecção. Concluiu-se que os suínos podem se infectar com BVDV-1 e excretar partículas virais potencialmente infecciosas, sendo capazes de transmitir o vírus a outros suínos através da lâmina d'água.(AU)

Effect of probiotics and xylo-oligosaccharide on performance,digestive enzyme activities,blood index and intestinal microflora of early weaned piglets / 中国兽医学报

To evaluate the effects of supplemental probiotics and xylo-oligosaccharide on performance,digestive enzyme activities,blood index and intestinal microflora.Two hundred and forty crossbred early weaned PIC piglets with an average initial weight of (6.83 + 0.9) kg,weaned at (21 ± 2) d of age,were divided into four groups.Control Ⅰ (positive diet,with no probiotics and xylo-oligosaccharide but more fish meal,whey powder and little soybean meal),Control Ⅱ (negative diet,with no probiotics and xylo-oligosaccharide but less fish meal,whey powder and more soybean meal),Negative diet + 0.035 % probiotics,negative diet + 0.002% xylo-oligosaccharide.The results of theses studies suggested that whey powder and fish meal from 5.50% to 2.50%,soybean meal from 22.50% to 26.50% could result in decreasing of alimentary canal enzyme activity,blood sugar,total serum protein and the quantities of Bacillus in appendix(P<0.05),and raising of serum urea nitrogen,the quantities of Escherichia coli in appendix,diarrhea indexes and Feed/Gain(P<0.05).Addition of probiotics and xylo-oligosaccharide could significantly improve the activities of alimentary canal protein,lipase and amylase(P<0.05),decrease Feed/Gain and the levels of blood sugar and decrease the levels of serum urea nitrogen and improve protein equilibrium in blood and energy metabolism.The quantities of bacillus were improved,Escherichia coli were decreased in appendix(P<0.05).Diarrhea indexes were decreased(P<0.05).Whether adding probiotics and xylo-oligosaecharide or not could not affect ADG and ADFI (P>0.05).Addition of probiotics and xylo-oligosaccharide could improve digestive function,beneficial microbial population of post-alimentary canal,Feed/Gain and prevent the diarrhea of piglets.