College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China.
National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, South China Agricultural University, Guangzhou 510642, China.
Viruses. 2021 Oct 14;13(10):2070. doi: 10.3390/v13102070.
Bacteriophages are the most abundant biological entities on earth and may play an important role in the transmission of antibiotic resistance genes (ARG) from host bacteria. Although the specialized transduction mediated by the temperate phage targeting a specific insertion site is widely explored, the carrying characteristics of "transducing particles" for different ARG subtypes in the process of generalized transduction remains largely unclear. Here, we isolated a new T4-like lytic phage targeting transconjugant C600 that contained plasmid pHNAH67 (KX246266) and encoded 11 different ARG subtypes. We found that phage AH67C600_Q9 can misload plasmid-borne ARGs and package host DNA randomly. Moreover, for any specific ARG subtype, the carrying frequency was negatively correlated with the multiplicity of infection (MOI). Further, whole genome sequencing (WGS) identified that only 0.338% (4/1183) of the contigs of an entire purified phage population contained ARG sequences; these were , , , and . The low coverage indicated that long-read sequencing methods are needed to explore the mechanism of ARG transmission during generalized transduction.
噬菌体是地球上最丰富的生物实体，可能在抗生素耐药基因 (ARG) 从宿主细菌传播中发挥重要作用。尽管针对特定插入位点的温和噬菌体介导的专门转导已被广泛探索，但在普遍转导过程中，“转导颗粒”对不同 ARG 亚型的携带特性在很大程度上仍不清楚。在这里，我们分离到一种针对含有质粒 pHNAH67 (KX246266) 和编码 11 种不同 ARG 亚型的转导体 C600 的新型 T4 样裂解噬菌体。我们发现噬菌体 AH67C600_Q9 可以错误加载质粒携带的 ARG 并随机包装宿主 DNA。此外，对于任何特定的 ARG 亚型，携带频率与感染复数 (MOI) 呈负相关。此外，全基因组测序 (WGS) 鉴定出整个纯化噬菌体群体的仅有 0.338%（4/1183）的基因组序列含有 ARG 序列；它们是 、 、 和 。低覆盖率表明需要使用长读测序方法来探索普遍转导过程中 ARG 传播的机制。
