Thanki Anisha M, Brown Nathan, Millard Andrew D, Clokie Martha R J
Department of Genetics and Genome Biology, College of Life Sciences, University of Leicester, Leicester, United Kingdom.
Front Microbiol. 2019 Jul 2;10:1491. doi: 10.3389/fmicb.2019.01491. eCollection 2019.
A common cause of human food poisoning is through ingestion of pork products contaminated with spp. Worryingly multi-drug resistant (MDR) strains have been isolated from pigs, which motivates the need for alternative antimicrobials. In this study isolation and characterization of 21 lytic phages is described. All 21 phages, labeled as SPFM phages were shown to efficiently infect MDR strains isolated from United Kingdom pigs and phages SPFM1, SPFM3, SPFM10, SPFM14, SPFM15, SPFM17, and SPFM19 could lyse 100% of strains tested. The phage genome sizes range from 233 to 242 Kb, which qualifies them as jumbo phages. All SPFM phage genomes are approximately 95% similar to each other by average nucleotide identity, they encode between 258-307 coding sequences and share 188 core genes. Phylogenetic analysis shows these phages are most similar to phages of the genus and to further characterize phages within the genus, genes under positive selection were identified. Several of the genes under evolutionary selection pressure were predicted to encode for proteins that interact with bacteria. We describe the phenotypic and genetic characterization of this novel phage set. As the phages efficiently kill MDR strains, they may offer a promising alternative to antibiotics.
人类食物中毒的一个常见原因是摄入被 spp. 污染的猪肉产品。令人担忧的是，已从猪身上分离出多重耐药（MDR） 菌株，这促使人们需要替代抗菌药物。在本研究中，描述了21种裂解性噬菌体的分离和特性。所有21种噬菌体，标记为SPFM噬菌体，均显示能有效感染从英国猪身上分离出的MDR 菌株，噬菌体SPFM1、SPFM3、SPFM10、SPFM14、SPFM15、SPFM17和SPFM19能裂解100%的测试菌株。噬菌体基因组大小在233至242 Kb之间，这使它们属于巨型噬菌体。所有SPFM噬菌体基因组通过平均核苷酸同一性彼此约95%相似，它们编码258 - 307个编码序列，并共享188个核心基因。系统发育分析表明这些噬菌体与 属的噬菌体最相似，为进一步表征该属内的噬菌体，鉴定了正选择下的基因。几个处于进化选择压力下的基因预计编码与细菌相互作用的蛋白质。我们描述了这组新型噬菌体的表型和遗传特性。由于这些噬菌体能有效杀死MDR 菌株，它们可能为抗生素提供一种有前景的替代品。
