[关键词]
[摘要]
金黄色葡萄球菌能够引起食源性疾病,易产生多重耐药性,因此噬菌体在金黄色葡萄球菌防控方面的应用受到了广泛关注。本研究分离了4株噬菌体SAPYZU-04、SAPYZU-15、SAPYZU-SapM13和SAPYZU-SapM14。并对其形态学特征,生物学特性以及全基因组序列进行分析。结果表明,烈性噬菌体SAPYZU-04和SAPYZU-15属于Helelleviridae科,温和噬菌体SAPYZU-SapM13和SAPYZU-SapM14属于Siphoviridae科。而且,烈性噬菌体SAPYZU-04和SAPYZU-15裂解率高达100% (51/51),然而温和噬菌体SAPYZU-SapM13和SAPYZU-SapM14的裂解率分别为94% (48/51)和86%(44/51)。当温度为40-60 ℃,pH值为3-13时,4株噬菌体的活性较高。一步生长曲线显示,烈性噬菌体SAPYZU-04和SAPYZU-15的潜伏期均为10 min,裂解量分别为210和322 pfu/ cell;而温和噬菌体SAPYZU-SapM13和SAPYZU-SapM14的潜伏期分别为15和25 min,裂解量分别为52和49 pfu/cell。全基因组序列分析结果表明4株噬菌体均不含任何毒力、耐药基因,但烈性噬菌体SAPYZU-04和SAPYZU-15具有多个裂解酶基因和DNA代谢相关基因。本研究证实2株烈性噬菌体SAPYZU-04和SAPYZU-15的裂解谱更广、潜伏期更短、爆发量更大,更适合作为潜在的生物抑菌剂,应用于食品安全领域。
[Key word]
[Abstract]
Staphylococcus aureus can causes foodborne diseases and is prone to multiple drug resistance. Therefore, the application of phages in the prevention and control of S. aureus has attracted extensive attention. In this study, four S. aureus bacteriophages SAPYZU-04, SAPYZU-15, SAPYZU-SapM13 and SAPYZU-SapM14 were isolated. The morphology, biological characteristics, and whole genomes of these four bacteriophages were analyzed. The results of transmission electron microscopy showed that the lytic phages SAPYZU-04 and SAPYZU-15 belonged to the Helelleviridae family, and the temperate phages SAPYZU-SapM13 and SAPYZU-SapM14 belonged to the Siphoviridae family. The host range revealed that the SAPYZU-04 and SAPYZU-15 showed the broadest host range, being lytic towards all the 51 (100%, 51/51) S. aureus isolates. However, the SAPYZU-SapM13 and SAPYZU-SapM14 exhibit lytic to 48 (94%, 48/51) and 44 (86%, 44/51) S. aureus isolates, respectively. Stability experiments showed that the activity of the four phages was higher when the temperature was 40-60 ℃ and pH was 3-13. The one-step growth curve suggested that the incubation period of SAPYZU-04 and SAPYZU-15 was 10 min, and the lyses were 210 and 322 pfu/ cell, respectively. The incubation period of SAPYZU-SapM13 and SAPYZU-SapM14 was 15 min and 25 min, respectively, and the lysis volume of Sapyzu-SAPM14 was 52 and 49 pfu/cell. Genome sequencing showed that none of the four phages contained any typical virulence and drug resistance genes, but the virulence phages SAPYZU-04 and SAPYZU-15 had multiple lyase genes and genes related to DNA metabolism. This study showed that the two strains SAPYZU-04 and SAPYZU-15 had wider host spectrum, shorter incubation period and larger outbreak amount, and were more suitable to be used as potential biological bacteriostatic agents in the field of food safety.
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[基金项目]
国家自然科学基金-青年基金项目(编号:32102100);中国博士后面上项目(编号:2022M712695)