The combined impact of xylo-oligosaccharides and gamma-irradiated astragalus polysaccharides on the immune response, antioxidant capacity, and intestinal microbiota composition of broilers.

The present study investigated the individual and combined effects of xylo-oligosaccharides (XOS) and gamma-irradiated astragalus polysaccharides (IAPS) on the immune response, antioxidant capacity and intestinal microbiota composition of broiler chickens. A total of 240 newly hatched Ross 308 chicks were randomly allocated into 5 dietary treatments including the basal diet (control), or the basal diet supplemented with 50 mg/kg chlortetracycline (CTC), 100 mg/kg XOS (XOS), 600 mg/kg IAPS (IAPS), and 100 mg/kg XOS + 600 mg/kg IAPS (XOS + IAPS) respectively. The results showed that birds in the control group had lower the thymus index and serum lysozyme activity than those in the other 4 groups (P < 0.05). Moreover, there was an interaction between XOS and IAPS treatments on increasing the serum lysozyme activity (P < 0.05). Birds in the CTC and XOS + IAPS groups had lower serum malondialdehyde concentration and higher serum total antioxidant capacity activity and mucosal interleukin 2 mRNA expression of jejunum than those in the control group (P < 0.05). In addition, birds in the control groups had lower duodenal and jejunal IgA-producing cells number than these in other 4 groups (P < 0.05). As compared with the CTC group, dietary individual XOS or IAPS administration increased duodenal IgA-producing cells number (P < 0.05). Meanwhile, there was an interaction between XOS and IAPS treatments on increasing duodenal and jejunal IgA-Producing cells numbers (P < 0.05). Dietary CTC administration increased the proportion of Bacteroides, and decreased the proportion of Negativibacillus (P < 0.05). However, dietary XOS + IAPS administration increased Firmicutes to Bacteroidetes ratio, the proportion of Ruminococcaceae, as well as decreased the proportion of Barnesiella and Negativibacillus (P < 0.05). In conclusion, the XOS and IAPS combination could improve intestinal mucosal immunity and barrier function of broilers by enhancing cytokine gene expression, IgA-producing cell production and modulates cecal microbiota, and the combination effect of XOS and IAPS is better than that of individual effect of CTC, XOS, or IAPS in the current study.

Creatine nitrate supplementation strengthens energy status and delays glycolysis of broiler muscle via inhibition of LKB1/AMPK pathway.

This study aimed to evaluate the effects of dietary creatine nitrate (CrN) on growth performance, meat quality, energy status, glycolysis, and related gene expression of liver kinase B1/AMP-activated protein kinase (LKB1/AMPK) pathway in Pectoralis major (PM) muscle of broilers. A total of 240 male Arbor Acres broilers (28-day-old) were randomly allocated to one of 5 dietary treatments: the basal diet (control group), and the basal diets supplemented with 600 mg/kg guanidinoacetic acid (GAA), 300, 600, or 900 mg/kg CrN (identified as GAA600, CrN300, CrN600, or CrN900, respectively). We found that dietary GAA and CrN supplementation for 14 d from d 28 to 42 did not affect broiler growth performance, carcass traits, and textural characteristics of breast muscle. GAA600, CrN600, and CrN900 treatments increased pH24h and decreased drip loss of PM muscle compared with the control (P < 0.05). The PM muscles of CrN600 and CrN900 groups showed higher glycogen concentration and lower lactic acid concentration accompanied by lower activities of phosphofructokinase (PFK), pyruvate kinase (PK), and lactate dehydrogenase (LDH) (P < 0.05). Simultaneously, GAA600 and all CrN treatments increased concentration of muscle creatine, phosphocreatine (PCr) and ATP, and decreased AMP concentration and AMP/ATP ratio (P < 0.05). Meanwhile, the concentrations of muscle creatine, PCr, and ATP were increased linearly, while muscle AMP concentration and AMP/ATP ratio were decreased linearly and quadratic as the dose of CrN increased (P < 0.05). GAA600, CrN600, and CrN900 treatments upregulated mRNA expression of CreaT in PM muscle, and CrN600 and CrN900 treatments downregulated GAMT expression in liver and PM muscle compared with the control or GAA600 groups (P < 0.05). The mRNA expression of muscle LKB1, AMPKα1, and AMPKα2 was downregulated linearly in response to the increasing CrN level (P < 0.05). Overall, CrN showed better efficacy on strengthening muscle energy status and improve meat quality than GAA at the some dose. These results indicate that CrN may be a potential replacement for GAA as a new creatine supplement.

Microbiota populations and short-chain fatty acids production in cecum of immunosuppressed broilers consuming diets containing γ-irradiated Astragalus polysaccharides.

This study was designed to evaluate the effects of γ-irradiated Astragalus polysaccharides (IAPS) on growth performance, cecal microbiota populations, and concentrations of cecal short-chain fatty acids of immunosuppressed broilers. A total of 144 one-day-old broiler chicks were randomly assigned into 3 groups: nontreated group (control), cyclophosphamide (CPM)-treated groups fed either a basal diet or the diets containing 900 mg/kg IAPS, respectively. On day 16, 18, and 20, broilers in the control group were intramuscularly injected with 0.5 mL sterilized saline (0.75%, wt/vol), and those in the CPM and IAPS groups were intramuscularly injected with 0.5 mL CPM (40 mg/kg of BW). The trial lasted 21 d. Compared with the control group, CPM treatment decreased the broiler average daily gain (ADG) and feed intake (P < 0.05) but did not affect the overall microbial diversity and compositions, as well as the concentrations of cecal acetate, propionate, and butyrate in cecum of broilers (P > 0.05). Dietary IAPS supplementation increased broiler ADG, Shannon index, and decreased Simpson index (P < 0.05). Specifically, broilers fed diets containing IAPS showed lower abundances of Faecalibacterium, Bacteroides, and Butyricicoccus and higher proportions of Ruminococcaceae UCG-014, Negativibacillus, Shuttleworthia, Sellimonas, and Mollicutes RF39_norank, respectively (P < 0.05). The IAPS treatment also increased butyrate concentration (P < 0.05) and tended to elevate acetate concentration (P = 0.052) in cecal digesta. The results indicated that IAPS are effective in increasing the cecal beneficial bacteria and short-chain fatty acids production, contributing to improvement in the growth performance of immunosuppressive broilers. These findings may expand our knowledge about the function of modified Astragalus polysaccharides in broiler chickens.

Glucose and lipid metabolism of broiler chickens fed diets with graded levels of corn resistant starch.

1. The aim of this study was to investigate the effects of graded levels of dietary corn resistant starch (RS) on glucose and lipid metabolism of broilers. 2. A total of 320 male broiler chicks (Arbor Acres, one-day-old) were randomly allocated to five dietary treatments, including a corn-soybean control diet, a corn-soybean based diet containing 20% corn starch, and three diets containing 4%, 8% and 12% RS by replacing corn starch with 6.67%, 13.33% and 20% Hi-Maize® 260 (identified as control, RS1, RS2, RS3 and RS4, respectively). Each treatment contained eight replicates with eight birds, and the experiment lasted 42 days. 3. Birds fed RS diets showed lower (P < 0.05) concentrations of serum low-density lipoprotein cholesterol and non-esterified fatty acid (NEFA) at d 21 and 42 of age, compared to the control. Lower (P < 0.05) hepatic apolipoprotein B concentration and citrate synthase (CS) activity, as well as a higher (P < 0.05) glycogen synthase (GS) concentration were observed in birds fed RS diets than those in the control group at d 21 of age. Consuming RS diets linearly increased (P < 0.01) serum glucose concentration, and linearly decreased (P < 0.01) NEFA concentrations in broilers at d 21 and 42 of age. Liver GS concentration and activities of hexokinase, pyruvate and CS were linearly increased (P < 0.01) in broilers at d 21 of age, but were linearly decreased (P < 0.05) in birds at d 42 of age in response to the increase of dietary RS levels. Feeding RS diets linearly decreased (P < 0.05) mRNA expressions of PC, PPARα and CPT-1 at d 21 of age and the mRNA expressions of SREBP-1 c, ChREBP, ACC and FAS at d 42 of age, and linearly increased (P < 0.05) the mRNA expressions of PEPCK, PC, LKB1, AMPKα1, PPARα, CPT-1 and L-FABP at d 42 of age. 4. Feeding broilers with diets containing higher concentration of RS promoted hepatic lipolysis and gluconeogenesis through activated AMPK signalling pathway and accelerated whole-body energy expenditures in the grower phase.

Growth performance, carcass traits and digestive function of broiler chickens fed diets with graded levels of corn resistant starch.

1. This study was conducted to assess the effects of graded levels of dietary corn resistant starch (RS) on growth performance, carcass traits, nutrient retention, digestive organ index, intestinal morphology, digestive enzyme activities, and mRNA expression of certain nutrient transporters in broiler chickens.2. A total of 320, 1-d-old Arbor Acres broiler chickens were randomly assigned to five dietary treatments, with eight replicates of eight birds in each. These treatments included one corn-soybean control diet, a corn-soybean based diet containing 20% corn starch, and three diets supplemented with 4%, 8% and 12% RS by replacing corn starch with 6.67%, 13.33% and 20% of Hi-Maize 260® (identified as control, RS1, RS2, RS3 and RS4, respectively). The feeding period lasted 42 days.3. Performance parameters including feed consumption, feed conversion, body weight gain and percentage of abdominal fat at d 42 of age, nutrient retention (including dry matter, fat, total starch and nitrogen free extract), and apparent metabolisable energy was measured from d 18 to 20 and d 39 to 41 and showed negative linear responses to increasing dietary RS level (P < 0.05). Birds fed the RS3 and RS4 diets showed higher relative weight of duodenum, jejunum and ileum, as well as lower villus height and villus height/crypt depth compared to the control (P < 0.05). The activity of pancreatic trypsin of birds at d 21 and 42 of age decreased linearly in response to the increase of dietary RS level (P < 0.01). There were linear changes in up-regulated mRNA expression of SGLT-1 and down-regulated mRNA expression of GLUT-2 with increasing proportion of RS at d 21 and 42 of age (P < 0.05), respectively.4. It was concluded that feeding broilers with diets containing higher concentrations of RS impaired the development of small intestine, which resulted in lower apparent total tract retention of nutrients and poorer body weight gain, feed efficiency and carcass traits of broiler chickens.

Dietary taurine supplementation enhances antioxidative capacity and improves breast meat quality of broiler chickens.

1. The aim of this study was to determine the effect of dietary taurine supplementation on growth performance, meat quality and antioxidant responses in breast muscle of broiler chickens.2. A total of 72 Arbor Acres broiler chickens (28-day-old) with similar body weight were randomly allocated into two groups, and fed either 0 g/kg (control; C) or 5 g/kg taurine-supplemented diets (TS) for 14 days.3. The results showed that TS had no effect on growth performance or chemical composition of breast muscle in broilers. The drip and cooking losses were significantly decreased (P < 0.05), and the pH24h of breast muscle were increased (P < 0.05) in the TS group. Meanwhile, broilers in the TS group exhibited significantly higher (P < 0.05) scavenging activities of superoxide and 2,2-diphenyl-1-picrylhydrazyl radicals, and lower (P < 0.05) contents of carbonyl, malondialdehyde, and 4-hydroxynonenal. TS increased (P < 0.05) total antioxidant capacity and superoxide dismutase activities. Moreover, TS significantly upregulated (P < 0.05) the mRNA expressions of nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase 1, NAD(P)H quinone dehydrogenase 1, superoxide dismutase, catalase, and glutathione peroxidase.4. These findings suggested that TS enhanced antioxidative capacity and improved breast meat quality of broilers via activating the Nrf2 pathway.

Protective effects of γ-irradiated Astragalus polysaccharides on intestinal development and mucosal immune function of immunosuppressed broilers.

This study was aimed to assess the protective effects of γ-irradiated Astragalus polysaccharides (IAPS) on the development of small intestine and intestinal mucosal immunity of immunosuppressed broilers induced by cyclophosphamide (CPM). A total of 384 one-day-old broiler chicks with similar initial weight were randomly assigned into 6 groups: non-treated group (control), and CPM-treated groups fed either a basal diet or the diets containing 900 mg/kg APS, or 900, 600, 300 mg/kg IAPS, respectively. On days 16, 18, and 20, all broilers except for control group were intramuscularly injected with 0.5 mL CPM (40 mg/kg of BW). Broilers in the control group were intramuscularly injected with 0.5 mL sterilized saline (0.75%, wt/vol). This trial was lasted for 21 d. The results revealed that both APS and IAPS treatment elevated the duodenal IgA-producing cells number and the jejunal mRNA expression of interleukin-2 (IL-2), interleukin-10 (IL-10), and interferon γ of CPM-injected broilers (P < 0.05). The decreased jejunal villus height (VH), the ratio of VH to crypt depth (V/C), as well as the intestinal intraepithelial lymphocytes (IELs) and goblet cells number in CPM-injected broilers were elevated by dietary supplementation with 900 mg/kg APS or 900, 600 mg/kg IAPS (P < 0.05). The CPM-induced decrease in jejunum index, the duodenal VH and the jejunal IgA-producing cells number were only improved in the 900 mg/kg IAPS group (P < 0.05). Furthermore, the number of IELs and IgA-producing cells in duodenum, VH, V/C, the number of goblet cells, and mRNA expression of IL-2 and IL-10 in jejunum were higher in the 900 mg/kg IAPS group than those in the 900 mg/kg APS group (P < 0.05). In summary, IAPS possessed stronger immunomodulatory effect than APS at the same supplementation level. Therefore, gamma irradiation can be used as an alternative treatment to enhance the immunomodulatory activity of APS.

Analysis and forecast for multidrug-resistant Acinetobacter baumannii Infections among liver transplant recipients.

BACKGROUND: Acinetobacter baumannii (Ab) has become an important pathogenic bacterium with specific epidemic features in the intensive care unit. We explored the epidemiology of multidrug-resistant Ab infections among liver transplant recipients at the Liver Transplantation Center, 1st Affiliated Hospital of Shanghai Jiao Tong University. METHODS: Seventeen multidrug-resistant Ab strains were isolated from the sputum and bronchoalveolar lavage fluid specimens of 249 liver transplant recipients from January 2007 to December 2009. The drug resistance and minimum inhibitory concentration (MIC) for the 17 Ab strains were determined. The Ab strains were genotyped with the use of repetitive element-based polymerase chain reaction. The risk factors were also characterized by single-factor and multifactor analysis to the clinical data of the 249 liver transplant recipients. RESULTS: The drug sensitivity results showed that the 17 Ab strains isolated displayed 100% drug resistance rate to aminoglycosides (gentamicin), quinolones (ciprofloxacin), penicillins (piperacillin), cephalosporins (ceftazidime, cefotaxime, and cefepime), and carbapenems (imipenem and meropenem). The 17 Ab strains could be divided into 3 genotypes: 1, 1, and 15 strains for types A, C, and B, respectively. Fungal culture positivity after operation (odds ratio [OR], 5.470) and tracheal intubation twice (OR, 11.538) were the independent risk factors for multidrug-resistant Ab strain infection. CONCLUSIONS: Type B multidrug-resistant Ab strains are prevalent in the liver transplantation center, and they could be transmitted clonally. Liver transplant recipients with postoperational fungal culture positivity and tracheal intubation twice are prone to multidrug-resistant Ab infections. Therefore, a high degree of vigilance should be paid to those recipients to avoid nosocomial Ab infections.

Prevalence of multidrug-resistant gram-negative bacilli producing extended-spectrum ß-lactamases (ESBLs) and ESBL genes in solid organ transplant recipients.

BACKGROUND: Multidrug-resistant (MDR) gram-negative bacilli pose a serious and rapidly emerging threat to recipients of solid organ transplants (SOTs). However, extended-spectrum ß-lactamases (ESBLs), as one of the cardinal mechanisms of resistance to antimicrobial agents in SOT recipients, remain obscure. The aim of this study was to investigate the prevalence of strains producing ESBLs in SOT patients with MDR gram-negative bacilli infections and to identify the ESBL genes carried by them. MATERIALS AND METHODS: Isolates from various clinical specimens of SOT recipients were identified using the VITEK 2 system, and their antibiotic sensitivity was determined by the 2-fold agar dilution method. Isolates suspected of producing ESBL enzymes were tested by an ESBL phenotypic confirmatory method, and the ESBL genotypes were determined by the polymerase chain reaction and sequencing. RESULTS: A total of 80 MDR gram-negative strains were isolated from 350 SOT recipients. Among these strains, 42 (52.5%) had an ESBL-positive phenotype; 33 (42.3%) patients with ESBL-positive infection were found. Molecular analysis showed that most of the isolates harbored blaCTX-M-9 (78.6%), blaTEM (81.0%), and blaSHV (69.0%) genes. All the ESBL-producing strains were susceptible to carbapenems. CONCLUSIONS: MDR gram-negative isolates from SOT recipients are frequently ESBL producers. TEM and CTX-M9 were the predominant ESBL types.