Département de Prévention, Diagnostic et Traitement des Infections, Hôpital Henri Mondor, APHP, Créteil, France.
EA 7380 Dynamyc, Université Paris-Est Créteil, Créteil, France.
Appl Environ Microbiol. 2022 Jun 14;88(11):e0022022. doi: 10.1128/aem.00220-22. Epub 2022 May 16.
Genus bacteria include important agricultural pathogens. Pectobacterium versatile isolates contain a chromosome-borne beta-lactamase, PEC-1. This enzyme is the closest relative of TEM-1, a plasmid-borne beta-lactamase widespread in the . We performed bioinformatics and phenotypic analyses to investigate the genetic and phenotypic features of PEC-1 and its frequency and ability to spread within genus . We also compared the characteristics of PEC-1 and TEM-1 and evaluated the likelihood of transfer. We found that was present principally in a small number of genetic environments in . Identical genetic environments were present in closely related species, consistent with the high frequency of genetic exchange within the genus . Despite the similarities between PEC-1 and TEM-1, their genetic environments displayed no significant identity, suggesting an absence of recent transfer. Phenotypic analyses on clonal constructs revealed similar hydrolysis spectra. Our results suggest that is the main reservoir of PEC-1, which seems to transfer to closely related species. The genetic distance between PEC-1 and TEM-1, and the lack of conserved elements in their genetic environments, suggest that any transfer that may have occurred must have taken place well before the antibiotic era. This study aimed to compare the chromosomal beta-lactamase from Pectobacterium versatile, PEC-1, with the well-known and globally distributed TEM-1 in terms of genetic and functional properties. Despite the similarities between the enzymes, we obtained no definitive proof of gene transfer for the emergence of from . Indeed, given the limited degree of sequence identity and the absence of a common genetic environment, it seems unlikely that any transfer of this gene has occurred recently. However, although was found mostly in one specific clade of the species, certain isolates from other closely related species, such as Pectobacterium brasiliense and Pectobacterium polaris, may also carry this gene inserted into common genetic environments. This observation suggests that genetic exchanges are frequent, accounting for the diffusion of between isolates from different species and, potentially, to exogenous mobile genetic elements.
属细菌包括重要的农业病原体。多形杆菌属分离株含有一个染色体携带的β-内酰胺酶，PEC-1。这种酶是质粒携带的β-内酰胺酶 TEM-1 的最接近的亲缘物，TEM-1 在 中广泛存在。我们进行了生物信息学和表型分析，以研究 PEC-1 的遗传和表型特征及其在属内传播的频率和能力。我们还比较了 PEC-1 和 TEM-1 的特征，并评估了转移的可能性。我们发现， 在 中主要存在于少数几种遗传环境中。与密切相关的物种中存在相同的 遗传环境，这与属内遗传交换的高频率一致。尽管 PEC-1 和 TEM-1 之间存在相似之处，但它们的遗传环境没有明显的同一性，表明最近没有发生转移。对克隆构建体的表型分析显示出相似的水解谱。我们的结果表明， 是 PEC-1 的主要储库，它似乎转移到密切相关的物种。PEC-1 和 TEM-1 之间的遗传距离以及它们遗传环境中缺乏保守元件表明，任何可能发生的转移都必须发生在抗生素时代之前。本研究旨在比较多形杆菌属的染色体β-内酰胺酶 PEC-1 与全球分布的 TEM-1 在遗传和功能特性方面的差异。尽管两种酶具有相似性，但我们没有确凿的证据表明 是从 中出现的。事实上，鉴于酶之间的序列同一性有限，以及缺乏共同的遗传环境，似乎不太可能最近发生了这种基因的转移。然而，尽管 在 属的一个特定分支中发现，但来自其他密切相关物种的某些分离株，如巴西果胶杆菌和极地果胶杆菌，也可能携带插入共同遗传环境的这种基因。这一观察结果表明，遗传交换是频繁发生的，这解释了 从不同 属分离株之间的扩散，以及可能向外源性可移动遗传元件的扩散。
