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.     

重庆一例猪源及鸡源大肠杆菌的分离鉴定和药敏试验

为了解重庆市北碚区龙凤桥镇养殖场中大肠杆菌对抗菌药物的敏感性,笔者在该镇某猪场及某鸡场采集了5份猪粪及10份鸡粪,从中分离出大肠杆菌,随后进行药物敏感性检测。结果显示:在15份粪便中分离到了15株大肠杆菌,包括5株猪源性大肠杆菌和10株鸡源性大肠杆菌;药物敏感性试验表明,这15株大肠杆菌的耐药率很高,2/3的菌株对超过23种抗菌药物有耐药性。     

Randomized Clinical Trial of Long‐Acting Oxytetracycline,Foot Trimming,and Flunixine Meglumine on Time to Recovery in Sheep with Footrot

Background: Internationally, foot trimming is used by most farmers, and parenteral antibacterials by some, to treat sheep with footrot. Nonsteroidal anti‐inflammatory drugs (NSAID) are sometimes used. No clinical trials have compared these treatments. Objectives: To investigate the above treatments on time to recovery from lameness and foot lesions in sheep with footrot. Animals: Fifty‐three sheep with footrot on a commercial farm in England. Methods: In a randomized factorial design, the sheep were allocated to 6 treatment groups. The treatments were oxytetracycline spray to all sheep (positive control) and one or more of parenteral administration of long‐acting oxytetracycline, flunixine meglumine, and foot trimming on day 1 or 6 of diagnosis. Follow‐up was for 15 days. Time to recovery from lameness and lesions was investigated with discrete‐time survival models. Results: There was significant association (P < .05) between recovery from lameness and lesions. Sheep receiving antibacterials parenterally recovered faster from lameness (odds ratio [OR]: 4.92 [1.20–20.10]) and lesions (OR: 5.11 [1.16–22.4]) than positive controls, whereas sheep foot trimmed on day 1 (lameness—OR: 0.05 [0.005–0.51]; lesions—OR: 0.06 [0.008–0.45]) or day 6 of diagnosis (lameness—OR: 0.07 [0.01–0.72]; lesions—OR: 0.07 [0.01–0.56]) recovered more slowly than positive controls. NSAID had no significant effect on recovery. Conclusions and Clinical Importance: If foot trimming on day 1 or 6 of diagnosis was stopped and parenteral antibacterials were used, then over 1 million sheep/annum lame with footrot in the United Kingdom would recover more rapidly with benefits to productivity. Globally, this figure would be much higher.