PDF(Pubmed)
Abstract：
UNASSIGNED: The rapid spread of plasmid-mediated tet(X4) conferring high tigecycline resistance poses a significant threat to public health. Escherichia coli as the most common pathogen which carries tet(X4) has been widely disseminated in China. Thus, comprehensive investigations are required to understand the mechanism of transmission of tet(X4)-positive E. coli.
UNASSIGNED: In this study, a total of 775 nonduplicate samples were collected in Guangdong, China from 2019 to 2020. We screened for tet(X4)-positive E. coli by PCR amplification and species identification. Furthermore, we analyzed the phylogenetics and genetic context of tet(X4)-positive E. coli through whole-genome sequencing and long-reads sequencing.
UNASSIGNED: Overall, 146 (18.84%) tet(X4)-positive E. coli were isolated, comprising 2 isolates from humans and 144 isolates from pigs. The majority of tet(X4)-positive E. coli exhibited resistance to multiple antibiotics but all of them were susceptible to amikacin and colistin. Phylogenetic analysis showed that ST877, ST871, and ST195 emerged as the predominant sequence types in tet(X4)-positive E. coli. Further analysis revealed various genetic environments associated with the horizontal transfer of tet(X4). Notably, a 100-kbp large fragment insertion was discovered downstream of tet(X4), containing a replicon and a 40-kbp gene cluster for the bacterial type IV secretion system.
UNASSIGNED: The high colonization rate of tet(X4)-positive E. coli in animals suggests that colonization as a key factor in its dissemination to humans. Diverse genetic context may contribute to the transfer of tet(X4). Our findings underline the urgent need for controlling the spread of plasmid-mediated tigecycline resistance.
UNASSIGNED: In this study, a total of 775 nonduplicate samples were collected in Guangdong, China from 2019 to 2020. We screened for tet(X4)-positive E. coli by PCR amplification and species identification. Furthermore, we analyzed the phylogenetics and genetic context of tet(X4)-positive E. coli through whole-genome sequencing and long-reads sequencing.
UNASSIGNED: Overall, 146 (18.84%) tet(X4)-positive E. coli were isolated, comprising 2 isolates from humans and 144 isolates from pigs. The majority of tet(X4)-positive E. coli exhibited resistance to multiple antibiotics but all of them were susceptible to amikacin and colistin. Phylogenetic analysis showed that ST877, ST871, and ST195 emerged as the predominant sequence types in tet(X4)-positive E. coli. Further analysis revealed various genetic environments associated with the horizontal transfer of tet(X4). Notably, a 100-kbp large fragment insertion was discovered downstream of tet(X4), containing a replicon and a 40-kbp gene cluster for the bacterial type IV secretion system.
UNASSIGNED: The high colonization rate of tet(X4)-positive E. coli in animals suggests that colonization as a key factor in its dissemination to humans. Diverse genetic context may contribute to the transfer of tet(X4). Our findings underline the urgent need for controlling the spread of plasmid-mediated tigecycline resistance.
摘要：
■赋予高度替加环素抗性的质粒介导的tet（X4）的快速传播对公众健康构成了重大威胁。大肠埃希菌作为携带tet(X4)的最常见病原体在我国已广泛传播。因此，需要进行全面的调查以了解tet（X4）阳性大肠杆菌的传播机制。
■在这项研究中，广东共采集了775个非重复样本，中国从2019年到2020年。我们通过PCR扩增和物种鉴定筛选了tet(X4)阳性大肠杆菌。此外，我们通过全基因组测序和长读数测序分析了tet(X4)阳性大肠杆菌的系统发育和遗传背景。
■总的来说，分离出146株(18.84%)tet(X4)阳性大肠杆菌,包括2个来自人类的分离株和144个来自猪的分离株。大多数tet（X4）阳性的大肠杆菌对多种抗生素表现出耐药性，但它们都对阿米卡星和粘菌素敏感。系统发育分析显示,ST877、ST871和ST195作为tet(X4)阳性大肠杆菌中的主要序列类型出现。进一步的分析揭示了与tet（X4）的水平转移相关的各种遗传环境。值得注意的是,在tet（X4）的下游发现了一个100-kbp的大片段插入，含有一个复制子和一个用于细菌IV型分泌系统的40-kbp基因簇。
■tet（X4）阳性大肠杆菌在动物中的高定殖率表明，定殖是其传播给人类的关键因素。不同的遗传背景可能有助于tet的转移(X4)。我们的发现强调了控制质粒介导的替加环素耐药性传播的迫切需要。
■在这项研究中，广东共采集了775个非重复样本，中国从2019年到2020年。我们通过PCR扩增和物种鉴定筛选了tet(X4)阳性大肠杆菌。此外，我们通过全基因组测序和长读数测序分析了tet(X4)阳性大肠杆菌的系统发育和遗传背景。
■总的来说，分离出146株(18.84%)tet(X4)阳性大肠杆菌,包括2个来自人类的分离株和144个来自猪的分离株。大多数tet（X4）阳性的大肠杆菌对多种抗生素表现出耐药性，但它们都对阿米卡星和粘菌素敏感。系统发育分析显示,ST877、ST871和ST195作为tet(X4)阳性大肠杆菌中的主要序列类型出现。进一步的分析揭示了与tet（X4）的水平转移相关的各种遗传环境。值得注意的是,在tet（X4）的下游发现了一个100-kbp的大片段插入，含有一个复制子和一个用于细菌IV型分泌系统的40-kbp基因簇。
■tet（X4）阳性大肠杆菌在动物中的高定殖率表明，定殖是其传播给人类的关键因素。不同的遗传背景可能有助于tet的转移(X4)。我们的发现强调了控制质粒介导的替加环素耐药性传播的迫切需要。
