Division of Clinical Microbiology, HUSLAB, Helsinki University Hospital, Haartmaninkatu 3, 00290 Helsinki, Finland.
Human Microbiome Research Program, Faculty of Medicine, University of Helsinki, P.O. Box 21 (Haartmaninkatu 3), 00014 Helsinki, Finland.
Viruses. 2021 Sep 22;13(10):1888. doi: 10.3390/v13101888.
The increase of livestock-associated methicillin-resistant (LA-MRSA) causes a threat to human health. LA-MRSA can be transmitted from animals to animal caretakers, which may further spread MRSA to communities and health care facilities. The objective of this work was to study the efficacy of phage treatment in the eradication of LA-MRSA from healthy carrier pigs. A total of 19 MRSA -positive weanling pigs were assigned to a test ( = 10) and a control group ( = 9). A phage cocktail containing three phages, or a control buffer was administered to the nares and skin of the pigs three times every two days, after which the phage and MRSA levels in nasal and skin swab samples were monitored for a three-week period. The sensitivity of the strains isolated during the follow-up period to the phage cocktail and each phage individually was analyzed and the pig sera were tested for antibodies against the phages used in the cocktail. The phage treatment did not cause any side effects to the pigs. Phages were found in the skin and nasal samples on the days following the phage applications, but there was no reduction in the MRSA levels in the sampled animals. Phage-resistant strains or phage-specific antibodies were not detected during the experiment. The MRSA load in these healthy carrier animals was only 10-100 CFU/swab or nasal sample, which was likely below the replication threshold of phages. The effectiveness of phage treatment to eradicate MRSA from the pigs could thus not be (reliably) determined.
猪源耐甲氧西林金黄色葡萄球菌（LA-MRSA）的增加对人类健康构成威胁。LA-MRSA 可以从动物传播给动物饲养员，这可能会进一步将 MRSA 传播到社区和医疗机构。本研究的目的是研究噬菌体治疗在根除健康携带猪中 LA-MRSA 的功效。总共将 19 头 MRSA 阳性断奶猪分配到试验组（n=10）和对照组（n=9）。每隔两天，将含有三种噬菌体的噬菌体鸡尾酒或对照缓冲液施用于猪的鼻腔和皮肤三次，之后监测鼻腔和皮肤拭子样本中噬菌体和 MRSA 水平持续三周。分析了在随访期间分离的菌株对噬菌体鸡尾酒和每种噬菌体的敏感性，并检测了猪血清中针对鸡尾酒中使用的噬菌体的抗体。噬菌体治疗未对猪造成任何副作用。在噬菌体处理后的几天，在皮肤和鼻腔样本中发现了噬菌体，但被采样动物的 MRSA 水平没有降低。在实验过程中未检测到噬菌体耐药株或噬菌体特异性抗体。这些健康携带动物中的 MRSA 负荷仅为 10-100 CFU/拭子或鼻腔样本，这可能低于噬菌体的复制阈值。因此，无法（可靠）确定噬菌体治疗根除猪中 MRSA 的效果。
