Dissanayake Upuli, Ukhanova Maria, Moye Zachary Daniel, Sulakvelidze Alexander, Mai Volker
Department of Epidemiology, College of Medicine, College of Public Health and Health Professions, University of Florida, Gainesville, FL, United States.
Laboratory 300B, Department of Epidemiology, Emerging Pathogens Institute, University of Florida, Gainesville, FL, United States.
Front Microbiol. 2019 Sep 10;10:1984. doi: 10.3389/fmicb.2019.01984. eCollection 2019.
We performed a study to (i) investigate efficacy of an spp-targeting bacteriophage cocktail (tentatively named F.O.P.) to reduce a human pathogenic strain O157:H7 in experimentally infected mice, and (ii) determine how bacteriophages impact the normal gut microbiota when compared with antibiotic therapy. A total of 85 mice were inoculated with O157:H7 strain Ec231 [nalidixic acid resistant (NalAc)] via oral gavage, and were randomized into six groups separated into three categories: 1st category received PBS or No phage/No PBS (control), 2nd category received either F.O.P., F.O.P. at 1:10 dilution, or only the phage component of F.O.P. (EcoShield PX), and 3rd category received the antibiotic ampicillin. All therapies were administered twice daily for four consecutive days including before and after bacterial challenge; except ampicillin which was administered only before and after bacterial challenge on day 0. Fecal samples were collected at Days 0, 1, 2, 3, 5, and 10. Samples were homogenized and plated on LB plates supplemented with NalAc to determine viable Ec231 counts. Body weights were measured at every fecal sample collection point. qPCR was performed using specific O157:H7 primers to quantify the number of O157:H7 genome copies. Microbiota community profiles were analyzed using Denature Gradient Gel Electrophoresis (DGGE) and 16S rRNA sequencing. F.O.P. significantly ( < 0.05) reduced O157:H7 pathogen counts by 54%. Ampicillin therapy significantly ( < 0.05) reduced O157:H7 pathogen counts by 79%. Greater initial weight-loss occurred in mice treated with ampicillin (-5.44%) compared to other treatment groups. No notable changes in the gut microbiota profiles were observed for control and F.O.P. groups. In contrast, the antibiotic group displayed noticeable distortion of the gut microbiota composition, only partially returning to normal by Day 10. In conclusion, we found that F.O.P. administration was effective in reducing viable O157:H7 in infected mice with a similar efficacy to ampicillin therapy. However, the F.O.P. bacteriophage preparation had less impact on the gut microbiota compared to ampicillin.
我们开展了一项研究，以（i）调查一种靶向特定菌的噬菌体鸡尾酒制剂（暂定名为F.O.P.）在实验感染小鼠中降低人致病性大肠杆菌O157:H7菌株的效果，以及（ii）与抗生素治疗相比，确定噬菌体对正常肠道微生物群的影响。总共85只小鼠通过口服灌胃接种了大肠杆菌O157:H7菌株Ec231[耐萘啶酸（NalAc）]，并随机分为六组，分为三类：第一类接受PBS或不接受噬菌体/不接受PBS（对照组），第二类接受F.O.P.、1:10稀释的F.O.P.或仅接受F.O.P.的噬菌体成分（EcoShield PX），第三类接受抗生素氨苄青霉素。所有治疗均连续四天每天给药两次，包括在细菌攻击前后；除氨苄青霉素仅在第0天细菌攻击前后给药。在第0、1、2、3、5和10天收集粪便样本。将样本匀浆并接种在补充有NalAc的LB平板上，以确定存活的Ec231数量。在每个粪便样本采集点测量体重。使用特异性大肠杆菌O157:H7引物进行qPCR，以定量大肠杆菌O157:H7基因组拷贝数。使用变性梯度凝胶电泳（DGGE）和16S rRNA测序分析微生物群落谱。F.O.P.显著（P<0.05）将大肠杆菌O157:H7病原体数量降低了54%。氨苄青霉素治疗显著（P<0.05）将大肠杆菌O157:H7病原体数量降低了79%。与其他治疗组相比，接受氨苄青霉素治疗的小鼠出现了更大的初始体重减轻（-5.44%）。对照组和F.O.P.组的肠道微生物群谱未观察到明显变化。相比之下，抗生素组的肠道微生物群组成出现了明显扭曲，到第10天才部分恢复正常。总之，我们发现给予F.O.P.可有效降低感染小鼠体内存活的大肠杆菌O157:H7，其效果与氨苄青霉素治疗相似。然而，与氨苄青霉素相比，F.O.P.噬菌体制剂对肠道微生物群的影响较小。
