L-Glutamine Supplementation Alleviates Constipation during Late Gestation of Mini Sows by Modifying the Microbiota Composition in Feces

Constipation occurs frequently in both sows and humans, particularly, during late gestation. The microbial community of the porcine gut, the enteric microbiota, plays a critical role in functions that sustain intestinal health. Hence, microbial regulation during pregnancy may be important to prevent host constipation. The present study was conducted to determine whether L-glutamine (Gln) supplementation improved intestinal function and alleviated constipation by regulation of enteric microbiota. 16S rRNA sequences obtained from fecal samples from 9 constipated sows (3 in the constipation group and 6 in the 1.0% Gln group) were assessed from gestational day 70 to 84. Comparative analysis showed that the abundance of intestinal-friendly microbiota, that is, Bacteroidetes (P=0.007) and Actinobacteria (P=0.037), was comparatively increased in the 1.0% Gln group, while the abundance of pernicious bacteria, Oscillospira (P<0.001) and Treponema (P=0.011), was decreased. Dietary supplementation with 1.0% Gln may ameliorate constipation of sows by regulated endogenous gut microbiota

Glutamine Ameliorates Mucosal Damage Caused by Immune Responses to Duck Plague Virus

The immune-releasing effects of L-glutamine (Gln) supplementation in duck plague virus (DPV)-infected ducklings were evaluated in 120 seven-day-old ducklings that were divided into 8 groups. The ducklings in control and DPV, 0.5Gln and DPV + 0.5Gln, 1.0Gln and DPV + 1.0Gln, and 2.0Gln and DPV + 2.0Gln received 0, 0.5, 1.0, and 2.0 g of Gln/kg feed/d by gastric perfusion, respectively. Then, the ducklings in control to 2.0Gln were injected with 0.2 mL of phosphate-buffered saline, while those in DPV to DPV + 2.0Gln were injected with DPV at 0.2 mL of 2000 TCID 50 (50% tissue culture infection dose) 30 minutes after gavage with Gln, sampled at 12 hours and days 1, 2, 4, and 6. Glutamine supplementation under physiological conditions enhanced immune function and toll-like receptor 4 (TLR4) expressions in a dose-dependent manner. An increase in Gln supplementation under DPV-infected conditions enhanced growth performance, decreased immunoglobulin (Ig) release in plasma and secretory IgA in the duodenum, ameliorated plasma cytokine levels, and suppressed overexpressions of the TLR4 pathway in the duodenum. The positive effects of Gln on the humoral immunity- and intestinal inflammation-related damage should be considered a mechanism by which immunonutrition can assist in the recovery from DPV infection

The Stability and Efficency of CPB Cells Were Acclimated for Virus Proliferation

Background: Vaccinations are still the most effective means of preventing and controlling fish viral diseases, and cells are an important substrate for the production of a viral vaccine. Therefore, the rapid-stable growth and virus sensitivity of cells are urgently needed. Methods: Chinese perch brain 100th passage (CPB p100) were acclimated in a low serum with 5% FBS L-15 for 50 passages, then transferred to 8% FBS L-15 for 150 passages. Additionally, the morphology and cell type of CPB 300th passage (CPB p300) cells were identified. We analyzed the transfection efficiency and virus sensitivity of CPB p300 cells, and then optimized the conditions of ISKNV, SCRV, and LMBV multiplication in CPB cells. Results: CPB p300 cells were more homogeneous, and the spread diameter (20–30) µm in CPB p300 cells became the dominant population. The doubling time of CPB p300 was 1.5 times shorter than that of CPB p100.However, multiplication rate of CPB p300 was 1.37 times higher than CPB p100. CPB p300 cells were susceptible to ISKNV, SCRV, and LMBV, and the optimal conditions of ISKNV, SCRV, and LMBV multiplication were simultaneous incubation, 0.6 × 105 cells/cm2 and MOI = 0.1; infection at 48 h, 0.8 × 105 cells/cm2 and MOI = 0.01; simultaneous incubation, 0.7 × 105 cells/cm2 and MOI = 0.05, respectively. The time and economic costs of ISKNV, SCRV, and LMBV multiplication in CPB p300 cells were significantly reduced. Conclusions: The acquisition of CPB p300 cells laid a good material foundation for the production of ISKNV, SCRV, and LMBV vaccines

Development of a New Marine Fish Continuous Cell Line Derived from Brain of Red Sea Bream (<i>Pagrosomus major</i>) and Its Application to Fish Virology and Heavy Metal Toxicology

Red sea bream (Pagrosomus major) is one of the most popular farmed marine teleost fish species. Fish cell lines are becoming important research tool in the aquaculture field, and they are suitable models to study fish virology, immunology and toxicology. To obtain a Pagrosomus major cell line for biological studies, a continuous cell line from brain of red sea bream (designated as RSBB cell line) was established and has been successfully subcultured over 100 passages. The RSBB cell line predominantly consisted of fibroblast-like cells and multiplied well in M199 medium supplemented with 10% fetal bovine serum at 28 °C. Karyotyping analysis indicated that the modal chromosome numbers of RSBB cells was 48. After transfection with pEGFP-N1, RSBB cells showed bright green fluorescence with a transfection efficiency approaching 8%. For toxicology study, it was demonstrated that metal Cd could induce cytotoxic effects of RSBB cells, accompanied with a dose-dependent MTT conversion capacity. Morphologically, cells treated with metal Cd produced rounding, shrinking and detaching and induced both cell apoptosis and necrosis. For virology study, the RSBB cells were highly susceptible to Nervous necrosis virus (NNV) and Singapore grouper iridovirus (SGIV) with steady titers (i.e., 108.0~8.3 TCID50 mL−1 and 107.0~7.2 TCID50 mL−1 respectively). Furthermore, an obvious cytopathic effect (CPE) could be observed in RSBB cells infected with Infectious spleen and kidney necrosis virus (ISKNV) and Siniperca chuatsi rhabdoviruses (SCRV). Meanwhile, all the infections were confirmed by polymerase chain reaction. The new brain cell line developed and characterized from red sea bream in this study could be used as an in vitro model for fish studies in the fields of toxicology and virology

Development of a Double-Antibody Sandwich ELISA for Rapid Detection of the MCP Antigen Concentration in Inactivated ISKNV Vaccines

Infectious spleen and kidney necrosis virus (ISKNV) resulted in severe systemic diseases with high morbidity and mortality in Siniperca chuatsi. Vaccination is the primary method for effective prevention and control of these diseases. The development of inactivated ISKNV vaccines made some progress, but the technique of quality evaluation is scarce. Herein, a measurement of the MCP (major capsid protein) antigen concentration for the inactivated ISKNV vaccine was developed by double-antibody sandwich ELISA. Firstly, mouse monoclonal antibodies against ISKNV particles and MCP were generated. Then, a double-antibody sandwich ELISA was developed using the monoclonal antibody 1C8 1B9 as the capture antibody and Biotin-3B12 6B3 as the detection antibody. A standard curve was generated using the MCP concentration versus OD value with the linear range of concentration of 4.69~300 ng/mL. The assay sensitivity was 0.9 ng/mL. The antigen content of three batches of inactivated ISKNV vaccines was quantitatively detected using the double-antibody sandwich ELISA. The results showed that MCP antigen contents of inactivated ISKNV vaccines were positively correlated with the viral titers. The newly established double-antibody sandwich ELISA provided a useful tool for the detection of antigen quality for ISKNV inactivated vaccines

Development of a Double-Antibody Sandwich ELISA for Rapid Detection of the MCP Antigen Concentration in Inactivated ISKNV Vaccines

Infectious spleen and kidney necrosis virus (ISKNV) resulted in severe systemic diseases with high morbidity and mortality in Siniperca chuatsi. Vaccination is the primary method for effective prevention and control of these diseases. The development of inactivated ISKNV vaccines made some progress, but the technique of quality evaluation is scarce. Herein, a measurement of the MCP (major capsid protein) antigen concentration for the inactivated ISKNV vaccine was developed by double-antibody sandwich ELISA. Firstly, mouse monoclonal antibodies against ISKNV particles and MCP were generated. Then, a double-antibody sandwich ELISA was developed using the monoclonal antibody 1C8 1B9 as the capture antibody and Biotin-3B12 6B3 as the detection antibody. A standard curve was generated using the MCP concentration versus OD value with the linear range of concentration of 4.69~300 ng/mL. The assay sensitivity was 0.9 ng/mL. The antigen content of three batches of inactivated ISKNV vaccines was quantitatively detected using the double-antibody sandwich ELISA. The results showed that MCP antigen contents of inactivated ISKNV vaccines were positively correlated with the viral titers. The newly established double-antibody sandwich ELISA provided a useful tool for the detection of antigen quality for ISKNV inactivated vaccines

A Novel and Effective Therapeutic Method for Treating <i>Aeromonas schubertii</i> Infection in <i>Channa maculata</i>

Aeromonas schubertii is a pathogen that severely affects aquatic animals, including the snakehead, Channa maculata. Lytic bacteriophages have been recognized as effective alternatives to antibiotics for controlling bacterial infections. However, there have been no reports of A. schubertii phages as far as we know. In this study, a lytic bacteriophage SD04, which could effectively infect A. schubertii, was isolated from pond water cultured with diseased snakehead. The SD04 phage formed small, round plaques on Petri dishes. Electron microscopy revealed a hexagonal head and a contractile tail. Based on its morphology, it may belong to the Myoviridae family. Two major protein bands with molecular weights of 50 and 38 kilodaltons were observed after the phage was subjected to SDS-PAGE. The phage showed a large average burst size, high specificity, and a broad host range. When stored at 4 °C, phage SD04 had high stability over 12 months and showed almost no variation within the first six months. All fish were healthy after both intraperitoneal injection and immersion administration of SD04, indicating the safety of the phage. After treatment with SD04, Channa maculata in both phage therapy groups and prevention groups showed high survival rates (i.e., 83.3 ± 3.3% and 100 ± 1.3%, respectively). Phage therapy inhibits bacterial growth in the liver, the target organ of the infected Channa maculat. The experimental results indicate the potential use of phage SD04 for preventing A. schubertii infection in Channa maculata

Artificial intelligence-based refractive error prediction and EVO-implantable collamer lens power calculation for myopia correction

Abstract Background Implantable collamer lens (ICL) has been widely accepted for its excellent visual outcomes for myopia correction. It is a new challenge in phakic IOL power calculation, especially for those with low and moderate myopia. This study aimed to establish a novel stacking machine learning (ML) model for predicting postoperative refraction errors and calculating EVO-ICL lens power. Methods We enrolled 2767 eyes of 1678 patients (age: 27.5 ± 6.33 years, 18–54 years) who underwent non-toric (NT)-ICL or toric-ICL (TICL) implantation during 2014 to 2021. The postoperative spherical equivalent (SE) and sphere were predicted using stacking ML models [support vector regression (SVR), LASSO, random forest, and XGBoost] and training based on ocular dimensional parameters from NT-ICL and TICL cases, respectively. The accuracy of the stacking ML models was compared with that of the modified vergence formula (MVF) based on the mean absolute error (MAE), median absolute error (MedAE), and percentages of eyes within ± 0.25, ± 0.50, and ± 0.75 diopters (D) and Bland-Altman analyses. In addition, the recommended spheric lens power was calculated with 0.25 D intervals and targeting emmetropia. Results After NT-ICL implantation, the random forest model demonstrated the lowest MAE (0.339 D) for predicting SE. Contrarily, the SVR model showed the lowest MAE (0.386 D) for predicting the sphere. After TICL implantation, the XGBoost model showed the lowest MAE for predicting both SE (0.325 D) and sphere (0.308 D). Compared with MVF, ML models had numerically lower values of standard deviation, MAE, and MedAE and comparable percentages of eyes within ± 0.25 D, ± 0.50 D, and ± 0.75 D prediction errors. The difference between MVF and ML models was larger in eyes with low-to-moderate myopia (preoperative SE >  − 6.00 D). Our final optimal stacking ML models showed strong agreement between the predictive values of MVF by Bland-Altman plots. Conclusion With various ocular dimensional parameters, ML models demonstrate comparable accuracy than existing MVF models and potential advantages in low-to-moderate myopia, and thus provide a novel nomogram for postoperative refractive error prediction and lens power calculation

Additional file 1: Figure S1. of Comparative genetic analysis and pathological characteristics of goose parvovirus isolated in Heilongjiang, China

GPV DNA amplification results. M: marker; Li: Liver; Lu: Lung; Ki: Kidney; Bu: Bursa of Fabricius; Pa: Pancreas; Du: Duodenum; Re: Rectum; Je: Jejunum; Il: Ileum; La: Large intestine; Sk: Skeletal muscle; Br: Brain; Tr: Trachea; 24 and 192: Un-inoculated 24 and 192 h; 1, 2, 3, 4, 5, 6, 7, 8, 9 and 10: Duck ID number in Table 3. 1: 4Li; 2: 4Sk; 3: 4Br; 4: 4La; 5: 7 Pa; 6: 2Li; 7: 2 Pa; 8: 3Br; 9:1 Pa;10:3Tr; 11: 4Ca; 12: 3Bu; 13: 4Je; 14: 1Ca; 15: 4Tr; 16:1Li; 17:1Lu; 18: 3Du; 19: 2Ki; 20: 3 Pa; 21:1Tr; 22: 4Lu; 23: 4Ki; 24: 3Ki; 25: 2Ca; 26: 3Re; 27: 7Lu; 28: 2Sk; 29: 2Lu; 30: 7Li; 31: 3La; 32:3Sk; 33: 10Du; 34: 7Tr; 35: 6 Pa; 36: 3Il; 37: 5Je; 38: 7Re; 39: 5 Pa; 40: 3Je; 41: 2Tr; 42: 6Br; 43: 7La; 44: 1Je; 45: 7Du; 46: 7Ca; 47: 1Bu; 48: 7Il; 49: 4Du; 50: 10Je; 51:1La; 52: 9La; 53: 8Bu; 54: 1Br; 55: 3Lu; 56: 2Br; 57:5Br; 58: 7Br; 59: 8Br; 60: 9Bu; 61: 1Il; 62: 10Il; 63: 2La; 64: 4Re; 65:10Br; 66: 10Ca; 67: 9Lu; 68: 9Tr; 69: 7Ki; 70: 4 Pa; 71:9Re; 72:8La; 73: 5Ca; 74: 6Ca; 75: 8Je; 76: 7Bu; 77: 5Li; 78: 6Li; 79: 2Je; 80: 8Ca; 81: 10La; 82: 5Lu; 83: 6Lu; 84: 2Il; 85:8Lu; 86:1Ki; 87:9Br; 88:5Ki; 89:6Ki; 90: 8Ki; 91: 9Ki; 92: 10Ki; 93: 2Bu; 94: 4Bu; 95: 5Bu; 96: 8Li; 97: 6Bu; 98: 3Li; 99:2Du; 100: 5Du; 101: 3Ca; 102: 9Li; 103: 6Du; 104: 4Il; 105:8Du; 106: 9Du; 107: 2Re; 108:10Li; 109:10Lu; 110: 5Re; 111:10Bu; 112: 8 Pa; 113:9 Pa; 114: 6Re; 115: 8Re; 116: 6Je; 117: 9Je; 118: 5Il; 119: 6Il; 120: 1Sk; 121:5Sk; 122 6Sk; 123:10 Pa; 124: 8Sk; 125: 9Sk; 126:10Re; 127:1Du; 128: 10Sk; 129: 5Tr; 130:1Re; 131:7Je; 132:8Tr; 133: 6Tr; 134: 10Tr; 135:9Ca; 136: 5La; 137: 6La; 138: 7Sk; 139: 8Il; 140: 9Il; 141: 24Ca; 142: 24Li; 143: 24Lu; 144: 24Ki; 145: 24Bu; 146: 24 Pa; 147: 24Du; 148: 24Re; 149: 24Il; 150: 24Je; 151: 24La; 152: 24Sk; 153: 24Br; 154: 24Tr; 155:192Ca; 156:192Li; 157:192Lu; 158:192Ki; 159:192Bu; 160: 192 Pa; 161: 192 Du; 162:192Re; 163:192Il; 164:192Je; 165:192La; 166:192Sk; 167:192Br; 168:192Tr; 169:192con. Figure S2. Duck embryo muscle tissues inoculated with serial dilutions. Dentified by PCR. A 1.2 × 102PFU. B 1.2 × 103PFU. C 1.2 × 104PFU. D 1.2 × 105PFU. (PDF 289 kb