Esposito Eliana P, Gaiarsa Stefano, Del Franco Mariateresa, Crivaro Valeria, Bernardo Mariano, Cuccurullo Susanna, Pennino Francesca, Triassi Maria, Marone Piero, Sassera Davide, Zarrilli Raffaele
Department of Public Health, University of Naples 'Federico II', Naples, Italy.
Department of Bioscience, University of Milan, Milan, Italy.
Front Microbiol. 2017 Nov 3;8:2135. doi: 10.3389/fmicb.2017.02135. eCollection 2017.
The emergence of carbapenemase producing Enterobacteriaceae has raised major public health concern. The aim of this study was to investigate the molecular epidemiology and the mechanism of carbapenem resistance acquisition of multidrug-resistant isolates from 20 neonates in the neonatal intensive care unit (NICU) of the V. Monaldi Hospital in Naples, Italy, from April 2015 to March 2016. Genotype analysis by pulsed-field gel electrophoresis (PFGE) and multi-locus sequence typing (MLST) identified PFGE type A and subtypes A1 and A2 in 17, 2, and 1 isolates, respectively, and assigned all isolates to sequence type (ST) 104. isolates were resistant to all classes of β-lactams including carbapenems, fosfomycin, gentamicin, and trimethoprim-sulfamethoxazole, but susceptible to quinolones, amikacin, and colistin. Conjugation experiments demonstrated that resistance to third-generation cephems and imipenem could be transferred along with an IncA/C plasmid containing the extended spectrum β-lactamase and carbapenem-hydrolyzing metallo-β-lactamase genes. The plasmid that we called pIncAC_KP4898 was 156,252 bp in size and included a typical IncA/C backbone, which was assigned to ST12 and core genome (cg) ST12.1 using the IncA/C plasmid MLST (PMLST) scheme. pIncAC_KP4898 showed a mosaic structure with into a class I integron, flanked by IS6 elements, a mercury resistance and a macrolide 2'-phosphotransferase clusters, , and conferring resistance to aminoglycosides, quinolones, sulfonamides, and trimethoprim, respectively, several genes predicted to encode transfer functions and proteins involved in DNA transposition. The acquisition of pIncAC_KP4898 carrying and contributed to the spread of ST104 in the NICU of V. Monaldi Hospital in Naples.
产碳青霉烯酶肠杆菌科细菌的出现引起了重大公共卫生关注。本研究的目的是调查2015年4月至2016年3月期间从意大利那不勒斯V. Monaldi医院新生儿重症监护病房（NICU）的20名新生儿中分离出的多重耐药菌株的分子流行病学及获得碳青霉烯耐药性的机制。通过脉冲场凝胶电泳（PFGE）和多位点序列分型（MLST）进行的基因型分析分别在17株、2株和1株菌株中鉴定出PFGE A型及A1和A2亚型，并将所有菌株归为序列型（ST）104。这些菌株对包括碳青霉烯类在内的所有β-内酰胺类、磷霉素、庆大霉素和甲氧苄啶-磺胺甲恶唑耐药，但对喹诺酮类、阿米卡星和黏菌素敏感。接合实验表明，对第三代头孢菌素和亚胺培南的耐药性可随携带超广谱β-内酰胺酶和碳青霉烯水解金属β-内酰胺酶基因的IncA/C质粒一起转移。我们称为pIncAC_KP4898的质粒大小为156,252 bp，包含一个典型的IncA/C主干，根据IncA/C质粒MLST（PMLST）方案，其被归为ST12和核心基因组（cg）ST12.1。pIncAC_KP4898呈现出镶嵌结构，带有一个I类整合子，两侧为IS6元件、一个汞抗性和一个大环内酯2'-磷酸转移酶簇，以及分别赋予对氨基糖苷类、喹诺酮类、磺胺类和甲氧苄啶耐药性的、几个预测编码转移功能和参与DNA转座的蛋白质的基因。携带 和 的pIncAC_KP4898的获得促成了ST104在那不勒斯V. Monaldi医院NICU中的传播。
