Beker Michal, Rose Simon, Lykkebo Claus A, Douthwaite Stephen
Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark.
Front Microbiol. 2018 Jun 26;9:1329. doi: 10.3389/fmicb.2018.01329. eCollection 2018.
Strains of the Pasteurellaceae bacteria and are major etiological agents of bovine respiratory disease (BRD). Treatment of BRD with antimicrobials is becoming more challenging due to the increasing occurrence of resistance in infecting strains. In Pasteurellaceae strains exhibiting resistance to multiple antimicrobials including aminoglycosides, beta-lactams, macrolides and sulfonamides, the resistance determinants are often chromosomally encoded within integrative and conjugative elements (ICEs). To gain a more comprehensive picture of ICE structures, we sequenced the genomes of six strains of and four strains of ; all strains were independent isolates and eight of them were multiple-resistant. ICE sequences varied in size from 49 to 79 kb, and were comprised of an array of conserved genes within a core region and varieties of resistance genes within accessory regions. These latter regions mainly account for the variation in the overall ICE sizes. From the sequence data, we developed a multiplex PCR assay targeting four conserved core genes required for integration and maintenance of ICE structures. Application of this assay on 75 isolates of and reveals how the presence and structures of ICEs are related to their antibiotic resistance phenotypes. The assay is also applicable to other members of the Pasteurellaceae family including and indicates how clustering and dissemination of the resistance genes came about.
巴氏杆菌科细菌菌株是牛呼吸道疾病（BRD）的主要病原体。由于感染菌株中耐药性的日益增加，用抗菌药物治疗BRD变得更具挑战性。在对包括氨基糖苷类、β-内酰胺类、大环内酯类和磺胺类在内的多种抗菌药物表现出耐药性的巴氏杆菌科菌株中，耐药决定因素通常在整合和接合元件（ICEs）内进行染色体编码。为了更全面地了解ICE结构，我们对6株[具体细菌名称未给出]和4株[具体细菌名称未给出]的基因组进行了测序；所有菌株均为独立分离株，其中8株具有多重耐药性。ICE序列大小从49到79 kb不等，由核心区域内一系列保守基因和辅助区域内多种耐药基因组成。后一类区域主要导致ICE总体大小的差异。根据序列数据，我们开发了一种针对ICE结构整合和维持所需的四个保守核心基因的多重PCR检测方法。将该检测方法应用于75株[具体细菌名称未给出]和[具体细菌名称未给出]分离株，揭示了ICE的存在和结构与其抗生素耐药表型之间的关系。该检测方法也适用于巴氏杆菌科的其他成员，包括[具体细菌名称未给出]，并表明了耐药基因的聚集和传播方式。
