摘要

      目标：
      抗菌素抗性基因（ARGs）可以通过可移动的基因元件进行转移，在细菌群落中传播耐药性方面发挥着关键作用。在质粒和转座子中已经报道了ARG在可移动遗传元件中的传递，但在噬菌体中较少报道。在这里，对七份人类粪便样本的噬菌体部分进行纯化和深度测序，以检测噬菌体颗粒中是否存在精氨酸。
      方法：
      用7份粪便样本（5份来自健康人，2份来自接受环丙沙星治疗前后的患者）提取噬菌体DNA，纯化后在MiSeq（Illumina）中测序。生成的读数经过质量检查和组装，然后用Kraken、PHASTER、VirSorter和Prokka分析生成的contigs。一些基因也通过定量PCR进行了验证。
      结果：
      从4～266株病毒中分离纯化的噬菌体DNA。病毒组分主要与尾状病毒目相对应，包括Siphoviridae科和Myoviridae科的噬菌体。定量PCR证实，在病毒DNA中检测到与耐药性相关的细菌基因。在环丙沙星处理后和处理前的样品中，发现携带ARG的噬菌体颗粒密度较高。
      结论：
      噬菌体颗粒中ARGs的发现支持了将噬菌体描述为有助于细菌耐药性传播的可移动元素，并提示环丙沙星治疗可能在释放载ARG颗粒中发挥作用，从而增加耐药性。

OBJECTIVES:

Antimicrobial resistance genes (ARGs) can be transferred by means of mobile genetic elements, which play a critical role in the dissemination of resistance in the bacterial community. ARG transmission within mobile genetic elements has been reported in plasmids and transposons but less frequently in bacteriophages. Here, the bacteriophage fraction of seven human faecal samples was purified and deep-sequenced to detect the presence of ARGs in the phage particles.

METHODS:

Seven faecal samples (five from healthy individuals and two from a patient before and after receiving ciprofloxacin treatment) were used to extract phage DNA, which was purified and then sequenced in a MiSeq (Illumina). Generated reads were checked for quality and assembled, and then the generated contigs analysed with Kraken, PHASTER, VirSorter and Prokka. Some genes were also validated by quantitative PCR.

RESULTS:

Analysis of the purified phage DNA by Kraken identified from 4 to 266 viruses in the samples. The viral fraction corresponded mainly to the order Caudovirales, including phages from the Siphoviridae and Myoviridae families. Bacterial genes associated with antimicrobial resistance were detected in the viral DNA, as confirmed by quantitative PCR. Higher densities of ARG-carrying phage particles were observed in the post- versus pre-ciprofloxacin treatment sample.

CONCLUSIONS:

The finding of ARGs in phage particles supports the description of phages as mobile elements contributing to the dissemination of bacterial antibiotic resistance and suggests ciprofloxacin treatment may play a role in the release of ARG-carrying particles, thereby increasing resistance.

        https://academic.oup.com/jac/article-abstract/74/4/854/5288153?redirectedFrom=fulltext