Replacing dietary antibiotics with 0.20% l-glutamine in swine nursery diets: impact on intestinal physiology and the microbiome following weaning and transport

Previous research demonstrates that supplementing 0.20% l-glutamine (GLN) in the diets of newly weaned and transported pigs improves growth rate to a similar extent as providing dietary antibiotics (AB). However, research comparing the effects of GLN vs. AB on intestinal physiology and the microbiome is limited. Therefore, the study objective was to compare the effects of supplementing nursery diets with GLN, AB, or no dietary antibiotics (NA) on intestinal physiology and the microbiome of pigs in a production environment following weaning and transport. Mixed-sex piglets (N = 480; 5.62 ± 0.06 kg body weight [BW]) were weaned (18.4 ± 0.2 d of age) and transported for 12 h in central Indiana, for two replicates, during the summer of 2016 and the spring of 2017. Pens were blocked by BW and allotted to one of the three dietary treatments (n = 10 pens/dietary treatment/replicate [8 pigs/pen]): AB (chlortetracycline [441 ppm] + tiamulin [38.6 ppm]), GLN (0.20% as-fed), or NA fed for 14 d. From day 14 to 34, pigs were fed common AB-free diets in two phases. On day 33, villus height:crypt depth tended to be increased (P = 0.07; 7.0%) in GLN and AB pigs vs. NA pigs. On day 33, glucagon-like peptide 2 (GLP-2) mRNA abundance was decreased (P = 0.01; 50.3%) in GLN and NA pigs vs. AB pigs. Crypt depth was increased overall on day 33 (P = 0.01; 16.2%) during the spring replicate compared with the summer replicate. Villus height:crypt depth was reduced (P = 0.01; 9.6%) during the spring replicate compared with the summer replicate on day 33. On day 13, tumor necrosis factor-alpha and occludin mRNA abundance was increased (P ≤ 0.04; 45.9% and 106.5%, respectively) and zonula occludens-1 mRNA abundance tended to be greater (P = 0.10; 19.2%) in the spring replicate compared with the summer replicate. In addition, AB pigs had increased (P = 0.01; 101.3%) GLP-2 mRNA abundance compared with GLN and NA pigs. Microbiome analysis indicated that on day 13, dietary treatment altered the microbiota community structure (P = 0.03). Specifically, the AB pigs tended to be distinct from both the NA and GLN pigs (P = 0.08), and Lactobacillus was increased nearly 2-fold in AB compared with NA pigs (q = 0.04) and GLN pigs (q = 0.22). In conclusion, GLN supplementation tended to improve some morphological markers of intestinal health similarly to AB pigs, while the microbiome composition in GLN pigs was more similar to NA pigs than AB pigs.     

口服肠溶制剂在兽药领域中的应用前景

介绍了肠溶制剂的制剂特点、肠溶制剂包衣原理、肠溶包衣材料和肠溶制剂类型等内容。结合规模化养殖场对药物饮水给药的需求,从兽用肠溶制剂的药物开发特点及近几年的国内外研究情况等两方面做以阐述,以期为兽用肠溶微丸、肠溶微囊制剂研发提供新的思路。     

Broad spectrum antimicrobial activity of leukocyte extracts from the American alligator (Alligator mississippiensis)

Leukocytes were isolated from whole blood of wild alligators by differential sedimentation. The leukocytes were disrupted in 5% AcOH and the crude extracts processed by ultrafiltration. The extracts were subjected to solvent exchange (0.1% AcOH) and the fraction that contained macromolecules between 1 and 10 kDa were subjected to further analyses. The acid extracts of the alligator leukocytes exhibited substantial antimycotic activities against six of eight species of Candida yeast tested. In addition, the alligator leukocyte extracts were effective as antimicrobial agents against 10 of 12 bacterial species, and displayed moderate activity against two enveloped viruses (human immunodeficiency virus-1 and herpes simplex virus-1_HF). Kinetic analyses revealed that the antimycotic effects of the leukocyte extract occurred rapidly, with 64% fungal growth inhibition within 3 min of exposure. The molecule(s) responsible for the antimicrobial activities were sensitive to proteases, heat-stable, acid soluble, and in the 1–10 kDa range. These data suggest that alligator leukocytes express cationic peptides that are responsible for their antimicrobial properties.     

New cytotoxic quinolone alkaloids from fruits of Evodia rutaecarpa

Three new quinolone alkaloids, 1-methyl-2-[7-hydroxy-(E)-9-tridecenyl]-4(1H)-quinolone (1), 1-methyl-2-[(Z)-4-nonenyl]-4(1H)-quinolone (2), 1-methyl-2-[(1E,5Z)-1,5-undecadienyl]-4(1H)-quinolone (3) and one new natural product, 1-methyl-2-[(E)-1-undecenyl]-4(1H)-quinolone (4), were isolated from the dried and nearly ripe fruits of Evodia rutaecarpa (Juss.) Benth., along with thirteen known compounds (5-17). In addition, one new artificial product, 1-methyl-2-[7-carbonyl-(E)-9-tridecenyl]-4(1H)-quinolone (1A) was also obtained. The structures of these compounds were determined by spectroscopic analyses. The cytotoxic activities of all of the compounds against the human cancer cell lines HL-60, N-87, H-460, and Hep G(2) cells were evaluated by MTT assay. The results showed that these alkaloids inhibited cell proliferation with IC(50) values between 14μM and 22μM.     

中草药饲料添加剂在甘肃省平凉市畜牧业发展中的应用前景

通过对甘肃省平凉市畜牧业发展的现状、存在问题、中草药饲料添加剂发展历史和优势、发展中草药饲料添加剂的前景4个方面的阐述,旨在让平凉市的动物养殖人员更加了解中草药这种纯天然的饲料添加剂,并将其应用于生产实践中,为平凉市的畜牧业健康发展提供绿色饲料产品。     

Plasmid‐mediated antimicrobial resistance in motile aeromonads from diseased Nile tilapia (Oreochromis niloticus)

For the sustainable farming of tilapia, proper maintenance of their health and adequate treatment for infections at appropriate time are inevitable. The indiscriminate use of antibiotics in aquaculture, as a part of treatment and as growth promoters, accelerates antimicrobial resistance (AMR) among the fish pathogens. In the present study, we have isolated diverse aeromonads from Nile tilapia and studied their antibiogram and plasmid profiling. Aeromonas hydrophila, Aeromonas veronii, Aeromonas sobria, Aeromonas dhakensis, Aeromonas caviae, Aeromonas jandaei and Aeromonas aquatica were isolated from infected tilapia (n = 150), and their Shannon wiener diversity index was calculated as 1.926. A. veronii was found to be the most multiple antibiotic‐resistant pathogen with the MAR index of 0.46, and A. aquatica was noticed as the least resistant isolate. The minimum inhibitory concentration of resistant antibiotics was shown as >256 mcg/ml for most of the isolates. The virulent genes such as aerolysin and hemolysin were identified in all the isolates except A. aquatica. The detection of class 1 integrons, plasmid profiling and plasmid curing studies confirmed that AMR exhibited by most of the Aeromonas species is of plasmid mediated. This challenges the risk of wide spread of AMR among the pathogens and subsequent treatment of the infection.     

3种抗生素对尾巨桉愈伤组织诱导及植株再生的影响

【目的】研究潮霉素、卡那霉素和头孢霉素对尾巨桉愈伤组织诱导、不定芽分化及生根的影响,确立抑制农杆菌生长的头孢霉素质量浓度。【方法】以尾巨桉无菌苗茎段为外植体,先后接种于添加不同质量浓度抗生素的愈伤组织诱导培养基、不定芽诱导培养基以及生根培养基上,统计愈伤组织诱导率、不定芽诱导率和不定芽生根率,观察头孢霉素对农杆菌生长的影响。【结果】(1)培养基中的潮霉素、卡那霉素、头孢霉素的质量浓度分别为15,25,200 mg/L时,尾巨桉外植体的愈伤组织诱导率分别为6.7%,12.1%和26.7%;(2)潮霉素、卡那霉素、头孢霉素的质量浓度分别为15,25,250 mg/L时,不定芽分化受到明显抑制,不定芽诱导率分别仅有2.6%,10.2%和7.6%;(3)潮霉素、卡那霉素、头孢霉素的质量浓度分别为15,25,250 mg/L时,不定芽生根困难,生根率分别为10.2%,16.2%和10.1%;当头孢霉素质量浓度≥200 mg/L时,农杆菌生长被完全抑制。【结论】尾巨桉对不同抗生素的敏感性存在差异,在尾巨桉遗传转化过程中,抗性愈伤组织与不定芽诱导的潮霉素适宜质量浓度为10 mg/L,卡那霉素为20 mg/L;生根诱导适宜的潮霉素和卡那霉素的质量浓度分别为15 和25 mg/L;抑制农杆菌生长的头孢霉素较适宜的质量浓度为200 mg/L。     

The potential for using cyanobacteria (blue-green algae) and algae in the biological control of plant pathogenic bacteria and fungi

Cyanobacteria (blue-green algae) and eukaryote algae occur in freshwater, marine, and terrestrial (soil) habitats. In fact, these microorganisms comprise most of the world's biomass. Although the cyanobacteria are mostly photoautotrophic, some are facultative heterotrophs, capable of growing on certain substrates in darkness. Also, some are non-phototrophic and hence, are obligate heterotrophs. A number of cyanobacteria and eukaryote algae, particularly macroalgae, produce various, biologically active compounds. These include antibiotics which in laboratory tests inhibited bacteria and fungi that incite diseases of humans. In addition, the following fungi which are of interest to plant pathologists, were inhibitedin vitro by substances produced by various cyanobacteria: The saprophytesChaetomium globosum, Cunninghamella blakesleeana, andAspergillus oryzae and the plant pathogensRhizoctonia solani andSclerotinia sclerotiorum. Extracts from seaweeds (macroalgae) sprayed on plants have been reported to reduce the incidence ofBotrytis cinerea (gray mold) on strawberries,Erysiphe polygoni (powdery mildew) on turnips, and damping-off of tomato seedlings. Because many cyanobacteria and algae produce a large number of antibacterial and antifungal materials, are almost never a threat to the environment, and many can be grown in quantity in mass culture, they are suitable candidates for exploitation as biocontrol agents of plant pathogenic bacteria and fungi. Much additional work remains to be done however, to thoroughly evaluate cyanobacteria and algae and their products for this role.     

Studies on the Respiratory Disease ‘Sonbobe’ in Camels in the Eastern Lowlands of Ethiopia

New epidemics of respiratory disease have caused 29.6 morbidity and 6.4% mortality in camels in the Somalia region of Ethiopia. The major clinical signs observed were fever of 40–41.5°C, depression, cough, loss of appetite and a watery nasal discharge that became mucopurulent at a later stage. Finally, the camel became recumbent and extended its neck straight along the ground. Some of the animals died within 8–9 days. The major post-mortem lesions were hydrothorax, adhesion of the lung to the thorax, red and grey hepatization, emphysema, hydropericardium and fibrinous pericarditis. A treatment trial indicated that oxytetracycline was more effective than a combination of penicillin and streptomycin, the results showing a significant difference (p>0.05) between the treated and control groups. The bacteria isolated from lung, thoracic fluid and whole blood were Pasteurella haemolytica. Further studies on the epidemiology of this disease, the identification of the serotypes involved, and the demonstration of any primary viral initiating agent are recommended to allow the development of preventive methods.