Staphylococcus aureus and biofilms:transmission, threats, and promising strategies in animal husbandry

Staphylococcus aureus(S. aureus) is a common pathogenic bacterium in animal husbandry that can cause diseases such as mastitis, skin infections, arthritis, and other ailments. The formation of biofilms threatens and exacerbates S. aureus infection by allowing the bacteria to adhere to pathological areas and livestock product surfaces, thus triggering animal health crises and safety issues with livestock products. To solve this problem, in this review, we provide a brief overview of the harm caused by S. aureus and its biofilms on livestock and animal byproducts(meat and dairy products). We also describe the ways in which S. aureus spreads in animals and the threats it poses to the livestock industry. The processes and molecular mechanisms involved in biofilm formation are then explained. Finally, we discuss strategies for the removal and eradication of S. aureus and biofilms in animal husbandry, including the use of antimicrobial peptides, plant extracts, nanoparticles, phages, and antibodies. These strategies to reduce the spread of S. aureus in animal husbandry help maintain livestock health and improve productivity to ensure the ecologically sustainable development of animal husbandry and the safety of livestock products.

Effects of magnesium on the performance of sows and their piglets

The objective of this study was to evaluate the effects of supplemental magnesium （Mg） on the performance of gilts and parity 3 sows and their piglets. Fifty-six grits （Trial 1） and 56 sows （Trial 2） were assigned to one of 4 treatments according to their mating weight, respectively. The treatments comprised corn-soybean meal based gestation and lactation diets （0.21% magnesium） supplemented with 0, 0.015, 0.03, or 0.045% Mg from mating until weaning. The results showed that magnesium supplementation significantly （P 〈 0.05） reduced the weaning to estrus interval in both gilts and sows. There were significant effects （P 〈 0.05） of supplemental magnesium on the total number of piglets born, born alive and weaned in sows. In late gestation and lactation, the digestibility of crude fiber （quadratic effects, P 〈 0.05）, and crude protein （P 〈 0.05）, were significantly influenced by magnesium in gilts and sows, respectively. There were differences among the 4 groups in terms of the apparent digestibility of dry matter and crude fiber in sows （P 〈 0.0S） during both early and late gestation. The apparent digestibility of gross energy was increased for sows in late gestation （P 〈 0.05）, and lactation （quadratic effects, P 〈 0.0S）. At farrowing and weaning, serum prolactin levels and alkaline phosphate activities linearly increased in sows as the Mg supplementation increased （P 〈 0.0.5）. Serum Mg of sows at farrowing and serum urea nitrogen of sows at weaning was significantly influenced by Mg supplementation （P 〈 0.05）. The Mg concentration in sow colostrum and the serum of their piglets were increased by supplemental magnesium （P 〈 0.05）. In addition, growth hormone levels were linearly elevated （P 〈 0.05） in the serum of piglets suckling sows. Our data demonstrated that supplemental magnesium has the potential to improve the reproduction performance of sows, and the suitable supplemental dose ranged from 0.015% to 0.03%.

Experience in New Socialist Countryside Planning and Construction and Recommendations: A Case Study of Haotang Village in Xinyang City of Henan Province

Taking Haotang Village in Xinyang City of Henan Province as an example,this paper analyzed experience of this village in development of new socialist countryside construction. The new socialist countryside planning and construction should attach importance to research on original spatial pattern of villages,really respect and bring into play subject function of farmers,and deeply explore rural financial services. It is expected to provide reference for future new socialist countryside planning and construction.

Clostridium species as probiotics:potentials and challenges

Clostridium species,as a predominant cluster of commensal bacteria in our gut,exert lots of salutary effects on our intestinal homeostasis.Up to now,Clostridium species have been reported to attenuate inflammation and allergic diseases effectively owing to their distinctive biological activities.Their cellular components and metabolites,like butyrate,secondary bile acids and indolepropionic acid,play a probiotic role primarily through energizing intestinal epithelial cells,strengthening intestinal barrier and interacting with immune system.In turn,our diets and physical state of body can shape unique pattern of Clostridium species in gut.In view of their salutary performances,Clostridium species have a huge potential as probiotics.However,there are still some nonnegligible risks and challenges in approaching application of them.Given this,this review summarized the researches involved in benefits and potential risks of Clostridium species to our health,in order to develop Clostridium species as novel probiotics for human health and animal production.

Pyrroloquinoline quinone regulates the redox status in vitro and in vivo of weaned pigs via the Nrf2/HO-1 pathway

Background:Oxidative stress is a main cause of piglet gut damage and diarrhea.Pyrroloquinoline quinone(PQQ),is a novel redox cofactor with antioxidant properties.However,the effect and mechanism that PQQ supplementation decreases oxidative injury in weaned pigs is not understood.Therefore,the aim of this study is to confirm the effect of PQQ on regulating redox status in weaned pigs and the mechanism for antioxidant function by porcine intestinal epithelial cell line(IPEC-J2)challenged with H_(2)O_(2).Results:Experiment 1,144 Duroc×Landrace×Yorkshire pigs(weaned at 28 d)were allocated to four groups:received a basal diet(control)and diets supplemented with 0.15%,0.30%and 0.45%PQQ,respectively.On d 28,growth performance,diarrhea incidence and redox factors were measured.Experiment 2,IPEC-J2 were treated with or without PQQ in the presence or absence of H_(2)O_(2)for indicated time points.Experiment 3,IPEC-J2 were transfected with or without Nrf2 siRNA,then treated according to Experiment 2.The cell viability,redox factors,protein of tight junctions and Nrf2 pathway were determined.In vivo,PQQ supplementation demonstrated dose-related improvements in average daily gain,and gain to feed ratio(Linear P<0.05).During d 0–28,compared to controls,0.45%PQQ supplementation for pigs decreased diarrhea incidence and MDA content in liver and jejunum,and increased concentration of SOD in liver;0.3%PQQ supplementation decreased ileal and liver MDA concentration;and 0.15%PQQ supplementation decreased ileal MDA concentration(P<0.05).In vitro,compared to cells cultured with H_(2)O_(2),pre-treatment with PQQ increased cell viability,tight junction proteins expression including ZO-1,ZO-2,Occludin and Claudin-1;and decreased ROS concentration and level of Caspase-3(P<0.05);as well as upregulated the ratio of Bcl-2 to Bax and protein expression of nuclear Nrf2,HO-1.Notably,Nrf2 knockdown by transfection with Nrf2 siRNA largely abrogated the positive effects of PQQ pretreatment on H_(2)O_(2)-induced intracellular changes.Conclusions:PQQ administration attenuated oxidative stress in weaned pigs which is associated with activation of Nrf2/HO-1 pathway.

Fat deposition deficiency is critical for the high mortality of pre-weanling newborn piglets

Background: The high mortality of pre-weanling piglets is a dominant challenge which severely restricts the development of pig industry. A number of factors including nutrients imbalance and temperature variation during postnatal period of piglets have been reported to closely associated with the high mortality of postnatal piglets.This study aims to find out the relationship between fat deposition and survival of newborn piglets.Results: There were no differences in organ coefficient and bone density between the surviving and dead piglets(P > 0.05). The body weight and the fat deposition in the dead piglets were lower than the live individuals(P < 0.05).Consistently, the average sizes of white adipocytes in back and abdominal adipose tissues of dead piglets were smaller than the survivals(P < 0.05). The protein expression levels of adipocyte differentiation markers PPARγ and C/EBPα in the back and abdominal adipose tissues were lower in dead piglets compared to live piglets. The mRNA expressions of thermogenic markers PGC1α and PRDM16 in adipose tissues were decreased in the dead piglets(P < 0.05). The microarray of back fat samples from the surviving and dead piglets were conducted; two down-regulated genes namely AAMDC and CASTOR1 were identified from the dead piglets. According to quantitative real-time PCR(RT-PCR) analysis, the mRNA expression of AAMDC decreased, whereas CASTOR1 expression elevated in the dead piglets compared to the surviving piglets(P < 0.05).Conclusions: The fat deposition and adipocyte differentiation in the dead piglets are insufficient compared to the surviving piglets, which may attenuate the thermogenic ability of white adipose tissue(WAT). Our data indicate that fat deposition in newborn piglets is vital to their survival.

Effects of L-lysine·H2SO4 product on the intestinal morphology and liver pathology using broiler model

Background: Lysine is used widely in livestock production due to the shortage of feed protein resources.Llysine·H2SO4 contains L-lysine sulphate as well as fermentation co-products which contain other amino acids and phosphorus.However,there are few articles about L-lysine·H2SO4 product regarding intestinal morphology and liver pathology of broiler chickens.In this article,we focus on the absorption and metabolism of L-lysine·H2SO4 revealed in the variation of intestinal morphology and liver pathology to determine the tolerance of chicks for L-lysine·H2SO4.Methods: To evaluate the tolerance of broilers for L-lysine·H2SO4,240 one day old broilers were allocated randomly to one of five dietary treatments which included corn-soybean diets containing 0,1%,4%,7% or 10% L-lysine·H2SO4(L-lysine content = 55%).Results: Supplementation of 1% L-lysine·H2SO4 in the diet had no negative effects.However,4%,7% or 10% Llysine·H2SO4 supplementation produced negative responses on broiler performance,carcass characteristics,blood biochemistry,and particularly on intestinal morphology and liver pathology compared with broilers fed the control diet.Conclusion: Our results show that supplementation with 1% L-lysine·H2SO4 had no negative effects on performance,carcass characteristics,blood biochemistry,intestinal morphology and liver pathology in broilers,but supplementation with 4%,7% or 10% L-lysine·H2SO4 produced a negative response,particularly with respect to intestinal morphology and liver pathology.

Horizontal transfer of vanA between probiotic Enterococcus faecium and Enterococcus faecalis in fermented soybean meal and in digestive tract of growing pigs

Background: The aim of this study was to investigate the intergeneric transfer of vancomycin resistance gene vanA between probiotic enterococci in the fermentation progress of soybean meal and in the digestive tract of growing pigs.One vanA genotype vancomycin resistant E.faecium strain,Efm4,and one chloramphenicol-resistant E.faecalis strain,Efs2,were isolated from twenty-nine probiotic basis feed material/additive samples.For in vitro conjugation,Efm4 and Efs2 were used as starter to ferment soybean meal.For in vivo conjugation,thirty growing pigs were randomly assigned to five groups(n = 6),treated with a basic diet,or supplemented with 10% fermented soybean meal,1% Efm4,5% Efs2 or a combination of 1% Efm4 + 5% Efs2 for 7 d,respectively.Fecal samples of pigs in each group were collected daily for the isolation and dynamic analysis of Efm4,Efs2 and transconjugants.The sequence types(STs) of Efm4,Efs2 and transconjugants were analyzed by multilocus sequence typing(MLST).The vanA harboring plasmid in Efm4 and transconjugants was analyzed by S1-pulsed field gel electrophoresis(PFGE)and further verified by multiple alignments.Results: The results showed that,in FSBM,transconjugants were detected 1 h after the fermentation,with a conjugation frequency of ~ 10^-3 transconjugants/recipient.Transconjugants proliferated with Efm4 and Efs2 in the first 8 h and maintained steadily for 10 d till the end of the experiment.Additionally,in vivo experiment showed that transcojugants were recovered in one of six pigs in both FSBM and Efm4 + Efs2 groups,with conjugation frequency of ~ 10^-5 and ~ 10^-4,respectively.MLST revealed the ST of Efm4,Efs2 and transconjugants was ST1014,ST69 and ST69,respectively.S1-PFGE confirmed the existence of the vanA-harboring,142,988-bp plasmid,which was also a multi-drug resistant plasmid containing Tn1546-like transposon.Conclusions: The findings revealed the potential safety hazard existing in the commercial probiotic enterococci in China,because the horizontal transfer from farm to fork could potentially pose a safety risk to the public.

Integrative analysis of indirect calorimetry and metabolomics profiling reveals alterations in energy metabolism between fed and fasted pigs

Background: Fasting is a simple metabolic strategy that is used to estimate the maintenance energy requirement where the energy supply for basic physiological functions is provided by the mobilization of body reserves.However, the underlying metabolic components of maintenance energy expenditure are not clear. This study investigated the differences in heat production(HP), respiratory quotient(RQ) and plasma metabolites in pigs in the fed and fasted state, using the techniques of indirect calorimetry and metabolomics.Methods: Nine barrows(45.2 ± 1.7 kg BW) were fed corn-soybean based meal diets and were kept in metabolism crates for a period of 14 d. After 7 d adaptation, pigs were transferred to respiratory chambers to determine HP and RQ based on indirect calorimetry. Pigs were fed the diet at 2,400 k J ME/(kg BW0.6·d) during d 8 to 12. The last 2 d were divided into 24 h fasting and 48 h fasting treatment, respectively. Plasma samples of each pig were collected from the anterior vena cava during the last 3 d(1 d while pigs were fed and 2 d during which they were fasted).The metabolites of plasma were determined by high-resolution mass spectrometry using a metabolomics approach.Results: Indirect calorimetry analysis revealed that HP and RQ were no significant difference between 24 h fasting and 48 h fasting, which were lower than those of fed state(P < 0.01). The nitrogen concentration of urine tended to decrease with fasting(P = 0.054). Metabolomics analysis between the fed and fasted state revealed differences in15 compounds, most of which were not significantly different between 24 h fasting and 48 h fasting. Identified compounds were enriched in metabolic pathways related to linoleic acid metabolism, amino acid metabolism,sphingolipid metabolism, and pantothenate and Co A biosynthesis.Conclusion: These results suggest that the decreases in HP and RQ of growing pigs under fasting conditions were associated with the alterations of linoleic acid metabolism and amino acid metabolism. The integrative analysis also revealed that growing pigs under a 24-h fasting were more appropriate than a 48-h fasting to investigate the metabolic components of maintenance energy expenditure.

Poly-β-hydroxybutyrate alleviated diarrhea and colitis via Lactobacillus johnsonii biofilm-mediated maturation of sulfomucin

Maintainance of sulfomucin is a key end point in the treatment of diarrhea and inflammatory bowel disease(IBD).However,the mechanisms underlying the microbial sense to sulfomucin are poorly understood,and to date,there are no therapies targeting the secretion and maturation of sulfomucin in IBD.Herein,we biosynthesized poly-β-hydroxybutyrate(PHB)and found that PHB could alleviate inflammation caused by diarrhea and colitis by enhancing the differentiation of sulfomucin.Microbiota transplantation and clearance together demonstrate that PHB promoting sulfomucin is mediated by Lactobacillus johnsonii(L.johnsonii).Further studies revealed that PHB provides a favorable niche for L.johnsonii biofilm formation to resist disturbance and support its growth.L.johnsonii-biofilm alleviates colitis by regulating fucose residues to promote goblet cell differentiation and subsequent sulfomucin maturation.Importantly,PHB alleviates colitis by enhancing sulfomucin secretion and maturation in a L.johnsonii-dependent manner.PHB represents a class of guardians,acting as a safe probiotic-biofilm delivery system that significantly promotes probiotic proliferation.Altogether,this study adds weight to the possible role of probiotics and functional materials in the treatment of intestinal inflammation.The application of PHB and biofilm self-coating L.johnsonii carries high translational potential and may be of clinical relevance.

Gama-aminobutyric acid(GABA)alleviates hepatic inflammation via GABA receptors/TLR4/NF-kB pathways in growing-finishing pigs generated by super-multiparous sows

The offspring of super-multiparous sows face problems such as decreased growth performance,poor meat quality and even diseases in animal husbandry.Gama-aminobutyric acid(GABA)has long been known to promote growth and suppress inflammation,but little is known about the mechanisms.A total of 72 growing-finishing pigs from the 8th generation were randomly allotted to 2 groups with 6 replicates per treatment to receive a cornesoybean basal diet or the basal diet supplemented 20 mg/kg GABA for 60 d.After the animal-trial period,samples of serum and liver were collected for further analysis.Additionally,a lipopolysaccharide(LPS)-induced inflammatory model using HepG2 cells was established to explore the role of GABA on regulating hepatic inflammation.The results indicated that inflammatory cell infiltration occurs in the liver of progeny of super-multiparous sows,and dietary supplementation with GABA influenced liver morphology,increased activities of antioxidant enzymes and decreased the expression abundance of pro-inflammatory cytokines,including tumor necrosis factor-α(TNFα)and interleukin(IL)-1β,in the liver of growing-finishing pigs(P<0.05).In addition,GABA supplementation increased mRNA expressions of peroxisome proliferator-activated receptor g(PPARg)and GABA receptors(GABARs),and reduced the expression of toll-like receptor 4(TLR4)/nuclear factor-kB(NF-kB)signaling(P<0.05).Additionally,an in vitro experiment demonstrated that GABA decreased the expressions of hepatic TLR4/NF-kB signaling via activating GABARs under LPS-stress(P<0.05).In summary,liver injury may affect the growth performance of growing-finishing pigs by changing hepatic mitochondrial metabolism,the expression of pro-inflammatory cytokines and TLR4/NF-kB pathway and that GABA supplementation has a restorative effect by acting on GABARs.

Dietary modulation of endogenous host defense peptide synthesis as an alternative approach to in-feed antibiotics

Traditionally, antibiotics are included in animal feed at subtherapeutic levels for growth promotion and disease prevention.However, recent links between in-feed antibiotics and a rise in antibiotic-resistant pathogens have led to a ban of all antibiotics in livestock production by the European Union in January 2006 and a removal of medically important antibiotics in animal feeds in the United States in January 2017.An urgent need arises for antibiotic alternatives capable of maintaining animal health and productivity without triggering antimicrobial resistance.Host defense peptides(HDP) are a critical component of the animal innate immune system with direct antimicrobial and immunomodulatory activities.While in-feed supplementation of recombinant or synthetic HDP appears to be effective in maintaining animal performance and alleviating clinical symptoms in the context of disease, dietary modulation of the synthesis of endogenous host defense peptides has emerged as a cost-effective,antibiotic-alternative approach to disease control and prevention.Several different classes of smallmolecule compounds have been found capable of promoting HDP synthesis.Among the most efficacious compounds are butyrate and vitamin D.Moreover, butyrate and vitamin D synergize with each other in enhancing HDP synthesis.This review will focus on the regulation of HDP synthesis by butyrate and vitamin D in humans, chickens, pigs, and cattle and argue for potential application of HDP-inducing compounds in antibiotic-free livestock production.

Lipids and membrane-associated proteins in autophagy

Autophagy is essential for the maintenance of cellular homeostasis and its dysfunction has been linked to various diseases.Autophagy is a membrane driven process and tightly regulated by membrane-associated proteins.Here,we summarized membrane lipid composition,and membrane-associated proteins relevant to autophagy from a spatiotemporal perspective.In particular,we focused on three important membrane remodeling processes in autophagy,lipid transfer for phagophore elongation,membrane scission for phago-phore closure,and autophagosome-lysosome membrane fusion.We discussed the significance of the discoveries in this field and possible avenues to follow for future studies.Finally,we summarized the membrane-associated biochemical techniques and assays used to study membrane properties,with a discussion of their applications in autophagy.

Attitude Control of Rigid Body with Inertia Uncertainty and Saturation Input

In this paper, the attitude control problem of rigid body is addressed with considering inertia uncertainty,bounded time-varying disturbances, angular velocity-free measurement, and unknown non-symmetric saturation input. Using a mathematical transformation, the effects of bounded time-varying disturbances, uncertain inertia,and saturation input are combined as total disturbances. A novel finite-time observer is designed to estimate the unknown angular velocity and the total disturbances. For attitude control, an observer-based sliding-mode control protocol is proposed to force the system state convergence to the desired sliding-mode surface; the finite-time stability is guaranteed via Lyapunov theory analysis. Finally, a numerical simulation is presented to illustrate the effective performance of the proposed sliding-mode control protocol.

Autophagy and the nutritional signaling pathway

During their growth and development, animals adapt to tremendous changes in order to survive. These include responses to both environmental and physiological changes and autophagy is one of most important adaptive and regulatory mechanisms. Autophagy is defined as an autolytic process to clear damaged cellular organelles and recycle the nutrients via lysosomic degradation. The process of autophagy responds to special conditions such as nutrient withdrawal. Once autophagy is induced,phagophores form and then elongate and curve to form autophagosomes. Autophagosomes then engulf cargo,fuse with endosomes, and finally fuse with lysosomes for maturation. During the initiation process, the ATG1/ULK1(unc-51-like kinase 1) and VPS34(which encodes a class III phosphatidylinositol(Ptd Ins) 3-kinase) complexes are critical in recruitment and assembly of other complexes required for autophagy. The process of autophagy is regulated by autophagy related genes(ATGs). Amino acid and energy starvation mediate autophagy by activating m TORC1(mammalian target of rapamycin) and AMPactivated protein kinase(AMPK). AMPK is the energy status sensor, the core nutrient signaling component and the metabolic kinase of cells. This review mainly focuses on the mechanism of autophagy regulated by nutrient signaling especially for the two important complexes,ULK1 and VPS34.

Phage-displayed heptapeptide sequence conjugation significantly improves the specific targeting ability of antimicrobial peptides against Staphylococcus aureus

Broad-spectrum antibacterial drugs often lack specificity,leading to indiscriminate bactericidal activity,which can disrupt the normal microbial balance of the host flora and cause unnecessary cytotoxicity during systemic administration.In this study,we constructed a specifically targeted antimicrobial peptide against Staphylococcus aureus by introducing a phage-displayed peptide onto a broad-spectrum antimicrobial peptide and explored its structure–function relationship through one-factor modification.SFK2 obtained by screening based on the selectivity index and the targeting index showed specific killing ability against S.aureus.Moreover,SFK2 showed excellent biocompatibility in mice and piglet,and demonstrated significant therapeutic efficacy against S.aureus infection.In conclusion,our screening of phage-derived heptapeptides effectively enhances the specific bactericidal ability of the antimicrobial peptides against S.aureus,providing a theoretical basis for developing targeted antimicrobial peptides.