Prevention, Diagnosis and Eradication of Mycoplasma Contamination in Cell Culture.

Mycoplasmas, which are the smallest and simplest prokaryotes, lack a cell wall but possess the ability to undergo self-replication. Mycoplasma contamination is a common problem for laboratories engaging in cell culture. Due to their small size, Mycoplasmas can easily permeate filters designed to prevent bacterial and fungal contamination in cell culture. Although Mycoplasma contamination usually does not result in cell death, it can significantly affect cell proliferation, metabolism, and cause chromosomal aberrations. Therefore, it is crucial to detect and eliminate Mycoplasma contamination in cell culture. This step-by-step protocol presents a comprehensive approach to prevent Mycoplasma contamination in cell culture, as well as to detect and eradicate Mycoplasma to ensure accurate experimental and sequencing results.

Productive Performance, Serum Antioxidant Status, Tissue Selenium Deposition, and Gut Health Analysis of Broiler Chickens Supplemented with Selenium and Probiotics-A Pilot Study.

The effect and interaction of dietary selenium (Se) and probiotics on three yellow chicken growth performance, tissue Se content, antioxidant capacity, and gut health were studied from 0 to 70 days of age. A total of 400 one-day-old broilers were distributed into four groups (I-Se, O-Se, I-Se + pros, and O-Se + pros groups) consisting of a 2 × 2 factorial design. The main factors were the source of Se (I-Se = inorganic Se: 0.2 mg/kg sodium selenite; O-Se = organic Se: 0.2 mg/kg Selenium yeast) and the level of probiotics (0.5% EM or 0% EM, the component of EM mainly includes Lactobacillus and Yeast at the dose of 2 × 108 cfu/kg and 3 × 107 cfu/kg, respectively). Each treatment had 5 duplicates consisting of 20 broilers. The results showed that the I-Se group had a greater (p < 0.05) ratio of feed: weight gain (F/G) of broilers at Starter (0−35 d) than the other treatments. Compared to the I-Se group, the O-Se group increased (p < 0.05) Se concentrations in the liver, pancreas, breast muscles, thigh muscle, and the activity of total antioxidative capacity (T-AOC) in serum, as well as the relative abundance of Barnesiella and Lactobacillus in cecum. Meanwhile, probiotics enhanced (p < 0.05) Se concentrations in the pancreas, thigh muscle, serum, and the activity of T-AOC and glutathione peroxidase (GSH-Px), the duodenum's ratio of villi height to crypt depth (V/C), the jejunum villus height and V/C, and the ileum's villus height. Furthermore, the significant interactions (p < 0.05) between Se sources and the level of probiotics were observed in Se concentrations in the pancreas, thigh muscle, serum, crypt depth of duodenum, and villus height of jejunum of birds, and Barnesiella abundance in the cecal. In conclusion, our results demonstrate that the combination of O-Se + pros can improve broiler early growth performance, tissue Se content in the pancreas, thigh muscle, and serum, promote intestinal development, and regulate the composition of intestinal flora, suggesting a better combination. These findings provide an effective method of nutrient combination addition to improving the performance of three yellow chickens.

Potential Mechanism and Effects of Different Selenium Sources and Different Effective Microorganism Supplementation Levels on Growth Performance, Meat Quality, and Muscle Fiber Characteristics of Three-Yellow Chickens.

A trial was conducted to investigate the effects of different Se sources, including sodium selenite (S-Se) and selenium yeast (Y-Se) and different effective microorganism (EM) addition levels on growth performance, meat quality, and muscle fiber characteristics of three-yellow chickens and its potential mechanism. A total of 400 birds were randomly distributed into 4 groups (S-Se, S-Se + EM, Y-Se, and Y-Se + EM groups) consisting of a 2 × 2 factorial arrangement. The main factors were the source of Se (ISe = inorganic Se: 0.2 mg/kg S-Se; OSe = organic Se: 0.2 mg/kg Y-Se) and the level of EM (HEMB = high EM: 0.5% EM; ZEMB = low EM: 0% EM). Each treatment had 5 replicates and each replicate consisted of 20 broiler chickens. The trial lasted for 70 days. The results showed that, in breast muscle, the broiler chickens fed OSe source decreased the pH24h, drip loss, shear force, perimeter, cross-sectional area, and diameter, but increased the a 24 h * and density compared with the broiler chickens fed ISe source (p < 0.05); broiler chickens supplied with HEMB level decreased the cross-sectional area and diameter, but increased the pH24h, a 24 h , * and density compared with the broiler chickens supplied with ZEMB level (p < 0.05). In thigh muscle, OSe source and HEMB level also could improve the meat quality and change muscle fiber characteristics of broiler chickens (p < 0.05). Meat quality was correlated with the muscle fiber characteristics (p < 0.05). OSe source and HEMB level could regulate the expression levels of muscle fiber-relative genes in the breast and thigh muscles (p < 0.05). In conclusion, OSe source and HEMB level could improve the meat quality of the breast and thigh muscles of three-yellow chickens by changing the muscle fiber characteristics, and they changed the muscle fiber characteristics by regulating the expression levels of muscle fiber-relative genes.

Effects of Catalase on Growth Performance, Antioxidant Capacity, Intestinal Morphology, and Microbial Composition in Yellow Broilers.

The objective of this experiment was to study the effects of catalase (CAT) on growth performance, antioxidant capacity, intestinal morphology, and microbial composition of yellow broilers. Male Lingnan yellow broilers (360), aged 1 day, were randomly divided into control group (CON) (fed with a basic diet), R1 group (fed with basic diet + 150 U/kg catalase), and R2 group (fed with basic diet + 200 U/kg catalase). Each group had 8 replicates and 15 chickens in each replicate. The test is divided into the early stage (1-30 days) and the later stage (31-60 days). The results showed that compared with the control group, groups R1 and R2 significantly (p < 0.05) increased the weight gain and reduced (p < 0.05) the ratio of feed to gain in the early and the whole stages; prominently increased (p < 0.05) the concentration of total antioxidant capacity (T-AOC), the activities of CAT, superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) in livers, the activities of CAT and GSH-Px in serum, and CAT in the jejunum in the early and the later stages; markedly increased (p < 0.05) the villus height and the ratio of villus height to crypt depth of the duodenum in the early and the later stages, the villus height and the villus height:crypt depth ratio of the jejunum and ileum in the early stage, and significantly lowered (p < 0.05) the crypt depth of the duodenum (in the early and the later stages), jejunum, and ileum (in early stage); memorably (p < 0.05) increased the number of total bacteria and Bacteroidetes in ceca, as well as the number of Lactobacillus in the jejunum (p < 0.05) on the 30th; significantly (p < 0.05) increased the mRNA expression of junction adhesion molecule 2 (JAM2), mucin 2 (MCU2), and occlusal protein (occludin) in the duodenum in the early stage, and increased (p < 0.05) the mRNA expression of JAM2 in the jejunum in the later stage. Collectively, adding catalase (CAT) to the diet of yellow broilers can improve the growth performance and the antioxidant capacity, promoting the integrity of intestinal morphology, optimizing the composition of intestinal microorganisms, and upregulating the mRNA expression of tight junction protein.

Effects of dietary tributyrin and physterol ester supplementation on growth performance, intestinal morphology, microbiota and metabolites in weaned piglets.

AIM: This study was conducted to investigate the effects of dietary tributyrin (TB) and physterol ester (PSE) supplementation on the growth performance and intestinal health of weaned piglets. METHODS AND RESULTS: Ninety-six piglets were randomly allocated to one of four groups, including a control group (basal diet), TB group (basal diet + 1500 g t-1  TB), PSE group (basal diet + 300 g t-1 PSE) and TB + PSE group (basal diet + 1500 g t-1  TB + 300 g t-1 PSE). All groups had eight replicates with three piglets per replicate. The experiment lasted for 28 days. The results showed that dietary TB supplementation increased (p < 0.05) average daily feed intake and average daily gain, as well as the acetate and butyrate concentration in ileum, and dietary PSE supplementation decreased (p < 0.05) the ratio of feed to gain (F/G) on days 1-14 of the trial. Dietary TB or PSE alone supplementation improved the ratio of villus height to crypt depth (VH/CD) and the expression level of Occludin in ileum. The linear discriminant analysis effect size analysis identified eight biomarkers in the control group, 18 in the TB + PSE group, two in the PSE group in ileum respectively. Correlation analysis showed that the relative abundances of Enterococcus, and Streptococcus were positively correlated (p < 0.05) with propionate concentration, while the relative abundance of Clostridium_sensu_stricto_1 was negatively correlated (p < 0.05) with acetate concentration in ileum. CONCLUSION: These findings suggest that dietary TB or PSE alone supplementation could alter the growth performance, intestinal morphology, microbiota community and metabolites of weaned piglets. SIGNIFICANCE AND IMPACT OF THE STUDY: Weaning stress is a major cause of slow growth and increased diarrhoea in piglets. This study demonstrated that dietary TB and PSE presented a beneficial role in growth performance and gut health via regulating intestinal morphology, microbiota composition and metabolites.

Dietary Supplementation of EGF Ameliorates the Negatively Effects of LPS on Early-Weaning Piglets: From Views of Growth Performance, Nutrient Digestibility, Microelement Absorption and Possible Mechanisms.

Epidermal growth factor (EGF) plays an important role in nutrients absorption. However, whether it can be an effective additive to improve the growth performance and nutrients absorption in lipopolysaccharide (LPS) challenged early weaning piglets is still unknown. A 14-days trial was conducted to investigate how EGF attenuates the effect of LPS on the growth performance, nutrient digestibility, microelement absorption of early-weaned pigs, and study the underlying mechanism. A total of 48 early weaned piglets, aged 25 days, were randomly distributed to four groups (control, EGF, LPS and EGF + LPS groups) consisting of a 2 × 2 factorial design. The main factors were the level of LPS (HLPS = high LPS: 100 µg/kg body weight; ZLPS = low LPS: 0 µg/kg body weight) and EGF (HEGF = high EGF: 2 mg/kg diet; ZEGF = low EGF: 0 mg/kg diet). Each group had four replicates and each replicate consisted of three piglets. The results showed that piglets injected with HLPS level significantly decreased the average daily gain (ADG), and significantly increased the feed conversion ratio (FCR) compared with the piglets injected with ZLPS level, while piglets fed HEGF level significantly increased the average daily feed intake (ADFI) compared with the piglets fed ZEGF level (p < 0.05). Piglets injected with HLPS level significantly decreased the apparent digestibility of crude fat compared with the piglets injected with ZLPS level (p < 0.05). Piglets injected with HLPS level significantly increased the concentration of most microelements in the gastrointestinal tract chyme and feces, and significantly decreased the expression levels of most microelement transport-relative genes in the mucosa of gastrointestinal tissues compared with the piglets injected with ZLPS level (p < 0.05). Piglets fed HEGF level significantly decreased the concentration of microelement in the gastrointestinal tract chyme and feces, and significantly increased the expression levels of the microelement transport-relative genes in the mucosa of gastrointestinal tissues compared with the piglets fed ZEGF level (p < 0.05). In conclusion, dietary EGF could attenuate the negative effect of LPS exposure on the apparent digestibility of crude fat and microelement absorption of early-weaning piglets. EGF and LPS influenced the absorption of essential trace element through changing the expression levels of microelement transport-relative genes in the mucosa of gastrointestinal tissues. In the early weaning piglets, EGF can be used as an additive to increase the essential trace elements absorption.

Mechanistic insight into the gut microbiome and its interaction with host immunity and inflammation.

The intestinal tract is a host to 100 trillion of microbes that have co-evolved with mammals over the millennia. These commensal organisms are critical to the host survival. The roles that symbiotic microorganisms play in the digestion, absorption, and metabolism of nutrients have been clearly demonstrated. Additionally, commensals are indispensable in regulating host immunity. This is evidenced by the poorly developed gut immune system of germ-free mice, which can be corrected by transplantation of specific commensal bacteria. Recent advances in our understanding of the mechanism of host-microbial interaction have provided the basis for this interaction. This paper reviews some of these key studies, with a specific focus on the effect of the microbiome on the immune organ development, nonspecific immunity, specific immunity, and inflammation.