Costa Sofia Santos, Palma Cláudia, Kadlec Kristina, Fessler Andrea T, Viveiros Miguel, Melo-Cristino José, Schwarz Stefan, Couto Isabel
1 Global Health and Tropical Medicine, GHTM, Unidade de Microbiologia Médica, Instituto de Higiene e Medicina Tropical, IHMT, Universidade Nova de Lisboa , UNL, Lisbon, Portugal .
2 Institute of Farm Animal Genetics , Friedrich-Loeffler-Institut (FLI), Neustadt-Mariensee, Germany .
Microb Drug Resist. 2016 Dec;22(8):617-626. doi: 10.1089/mdr.2015.0352. Epub 2016 Jun 16.
Plasmids play a key role in the genetic plasticity and survival of Staphylococcus aureus in challenging environments. Although many S. aureus plasmids have been described, still few studies portray the plasmid content of a given S. aureus population. The aim of this work was to characterize the plasmids carried by a collection of 53 S. aureus isolates collected in a large hospital in Lisbon, Portugal, and investigate their role in conferring resistance to several antimicrobial agents. Plasmids were present in 44 out of the 53 isolates and were grouped into eleven AccI restriction profiles. Plasmid curing of representative strains and comparison of antimicrobial susceptibility profiles between pairs of isogenic strains proved to be a valuable guidance tool in the identification of plasmid-located resistance genes. The plasmids harbored several resistance genes, namely blaZ (resistance to β-lactams), erm(C) (resistance to macrolides, lincosamides, and streptogramin B), cadA (resistance to cadmium and zinc), cadD (resistance to cadmium), and qacA and smr (resistance to biocides and dyes). This study demonstrates the impact of plasmids on the resistance properties of S. aureus, highlighting their role in the dissemination of antibiotic, heavy metal, and biocide resistance genes, and survival of this major pathogen in the hospital environment.
质粒在金黄色葡萄球菌于挑战性环境中的遗传可塑性和生存中起着关键作用。尽管已描述了许多金黄色葡萄球菌质粒，但仍很少有研究描绘特定金黄色葡萄球菌群体的质粒组成。本研究的目的是对从葡萄牙里斯本一家大型医院收集的53株金黄色葡萄球菌分离株所携带的质粒进行表征，并研究它们在赋予对几种抗菌剂耐药性方面的作用。53株分离株中有44株存在质粒，并被分为11种AccI限制性酶切图谱。对代表性菌株进行质粒消除以及对同基因菌株对之间的抗菌药敏谱进行比较，被证明是鉴定位于质粒上的耐药基因的有价值的指导工具。这些质粒含有几个耐药基因，即blaZ（对β-内酰胺类耐药）、erm(C)（对大环内酯类、林可酰胺类和链阳菌素B耐药）、cadA（对镉和锌耐药）、cadD（对镉耐药）以及qacA和smr（对杀菌剂和染料耐药）。本研究证明了质粒对金黄色葡萄球菌耐药特性的影响，突出了它们在抗生素、重金属和杀菌剂耐药基因传播以及这种主要病原体在医院环境中生存方面的作用。
