Bicalho M L S, Machado V S, Nydam D V, Santos T M A, Bicalho R C
Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, United States.
Livest Sci. 2012 Apr;144(3):294-299. doi: 10.1016/j.livsci.2011.12.007. Epub 2012 Jan 12.
Diarrhea is an important cause of morbidity and mortality in neonatal calves. Several enteropathogens are associated with diarrhea in young calves, with Enterotoxigenic (ETEC) infection being the most common type of colibacillosis. The rise of antibiotic resistance in a number of medically important bacterial pathogens has revived interest in the use of bacteriophages as anti-bacterial therapeutic agents. Here we describe the results of a randomized, placebo-controlled, double-blinded study designed to evaluate the effect of an oral bacteriophage cocktail on fecal colony-forming units (CFU). Ten calves were enrolled in the study to either the bacteriophage group or the placebo group for 22 feedings. Calves in the bacteriophage treatment group (n = 6) received a total of 10 plaque-forming units (PFU) (volume = 5 ml) of each of four bacteriophages while the placebo group (n = 4) received only phosphate-buffered saline (5 ml). Fresh fecal samples and blood samples were collected daily from each calf and analyzed for bacterial count and presence of bacteriophage. -infecting phages were recovered from all phage-treated calves at concentrations of 10² to 10³ PFU per gram of rectal contents, but none was detected in serum. Phage treatment caused a reduction in fecal when compared to the control group: the mean log CFU for the placebo-treated group was 9.25 (SE = 0.42) versus 9.11 (SE = 0.34) for the phage-treated group, but the difference was not statistically significant.
腹泻是新生犊牛发病和死亡的重要原因。几种肠道病原体与幼龄犊牛腹泻有关，其中产肠毒素大肠杆菌（ETEC）感染是最常见的大肠杆菌病类型。许多医学上重要的细菌病原体中抗生素耐药性的增加，重新引发了人们对使用噬菌体作为抗菌治疗剂的兴趣。在此，我们描述了一项随机、安慰剂对照、双盲研究的结果，该研究旨在评估口服噬菌体混合物对粪便菌落形成单位（CFU）的影响。10头犊牛被纳入研究，分为噬菌体组或安慰剂组，进行22次投喂。噬菌体治疗组（n = 6）的犊牛每头接受4种噬菌体各10个噬菌斑形成单位（PFU）（体积 = 5 ml），而安慰剂组（n = 4）仅接受磷酸盐缓冲盐水（5 ml）。每天从每头犊牛采集新鲜粪便样本和血液样本，分析细菌计数和噬菌体的存在情况。在所有接受噬菌体治疗的犊牛的直肠内容物中均检测到感染噬菌体，浓度为每克10²至10³ PFU，但血清中未检测到。与对照组相比，噬菌体治疗使粪便中的细菌数量减少：安慰剂治疗组的平均对数CFU为9.25（标准误 = 0.42），而噬菌体治疗组为9.11（标准误 = 0.34），但差异无统计学意义。
