Touzain Fabrice, Le Devendec Laetitia, de Boisséson Claire, Baron Sandrine, Jouy Eric, Perrin-Guyomard Agnès, Blanchard Yannick, Kempf Isabelle
ANSES, Ploufragan Laboratory, Ploufragan, France.
Université Bretagne Loire, Rennes, France.
PLoS One. 2018 Jan 23;13(1):e0188768. doi: 10.1371/journal.pone.0188768. eCollection 2018.
Resistance to extended-spectrum cephalosporins (ESC) is a global health issue. The aim of this study was to analyze and compare plasmids coding for resistance to ESC isolated from 16 avian commensal and 17 avian pathogenic Escherichia coli (APEC) strains obtained respectively at slaughterhouse or from diseased broilers in 2010-2012. Plasmid DNA was used to transform E. coli DH5alpha, and the resistances of the transformants were determined. The sequences of the ESC-resistance plasmids prepared from transformants were obtained by Illumina (33 plasmids) or PacBio (1 plasmid). Results showed that 29 of these plasmids contained the blaCTX-M-1 gene and belonged to the IncI1/ST3 type, with 27 and 20 of them carrying the sul2 or tet(A) genes respectively. Despite their diverse origins, several plasmids showed very high percentages of identity. None of the blaCTX-M-1-containing plasmid contained APEC virulence genes, although some of them were detected in the parental strains. Three plasmids had the blaCMY-2 gene, but no other resistance gene. They belonged to IncB/O/K/Z-like or IncFIA/FIB replicon types. The blaCMY-2 IncFIA/FIB plasmid was obtained from a strain isolated from a diseased broiler and also containing a blaCTX-M-1 IncI1/ST3 plasmid. Importantly APEC virulence genes (sitA-D, iucA-D, iutA, hlyF, ompT, etsA-C, iss, iroB-E, iroN, cvaA-C and cvi) were detected on the blaCMY-2 plasmid. In conclusion, our results show the dominance and high similarity of blaCTX-M-1 IncI1/ST3 plasmids, and the worrying presence of APEC virulence genes on a blaCMY-2 plasmid.
对超广谱头孢菌素（ESC）的耐药性是一个全球性的健康问题。本研究的目的是分析和比较分别于2010 - 2012年在屠宰场或患病肉鸡中获得的16株禽源共生大肠杆菌和17株禽致病性大肠杆菌（APEC）中编码对ESC耐药性的质粒。用质粒DNA转化大肠杆菌DH5α，并测定转化子的耐药性。通过Illumina（33个质粒）或PacBio（1个质粒）获得从转化子制备的ESC耐药性质粒的序列。结果表明，这些质粒中有29个含有blaCTX-M-1基因，属于IncI1/ST3型，其中分别有27个和20个携带sul2或tet(A)基因。尽管它们来源不同，但一些质粒显示出非常高的同源性百分比。含blaCTX-M-1的质粒均不含有APEC毒力基因，尽管在亲本菌株中检测到了其中一些基因。三个质粒含有blaCMY-2基因，但没有其他耐药基因。它们属于IncB/O/K/Z样或IncFIA/FIB复制子类型。blaCMY-2 IncFIA/FIB质粒是从一株患病肉鸡分离的菌株中获得的，该菌株还含有blaCTX-M-1 IncI1/ST3质粒。重要的是，在blaCMY-2质粒上检测到了APEC毒力基因（sitA-D、iucA-D、iutA、hlyF、ompT、etsA-C、iss、iroB-E、iroN、cvaA-C和cvi）。总之，我们的结果显示了blaCTX-M-1 IncI1/ST3质粒的优势和高度相似性，以及blaCMY-2质粒上存在令人担忧的APEC毒力基因。
