NDM-1-encoding plasmid in Acinetobacter chengduensis isolated from coastal water.

Acinetobacter spp. may cause difficult-to-treat nosocomial infections due to acquisition of carbapenemases, including New Delhi metallo-β-lactamase (NDM). This genus has been pointed out as a possible actor in the early dissemination of blaNDM, and this gene has been documented in a variety of species. Here we describe an Acinetobacter chengduensis (isolate FL51) carrying blaNDM recovered from coastal water in Brazil. In vitro techniques included antimicrobial susceptibility and minimum inhibitory concentration tests, PCR, plasmid profile and matting-out/transformation assays. In silico approaches comprised comparative genomic analyses using appropriate databases. FL51 grew at room temperature in a variety of culture media, excluding MacConkey. It showed resistance to all beta-lactams tested and to ciprofloxacin. blaNDM-1 was identified, and a single replicon was observed in plasmid profile. In silico DNA hybridization revealed Acinetobacter FL51 as being Acinetobacter chengduensis. blaNDM-1 was flanked upstream by ISAba14-aphA6-ISAba125 and downstream by bleMBL-trpF-Δtat, inserted in a 41,068 bp non typeable plasmid named pNDM-FL51. This replicon showed high coverage and identity with other sequences present in plasmids deposited on the GenBank database, recovered almost exclusively from Acinetobacter spp., associated with hospital settings and animal sources. We described a recently described environmental Acinetobacter species carrying a plasmid-borne blaNDM associated with a Tn125-like structure. Our findings suggest that replicon may play an important role in blaNDM dissemination among distinct settings within this genus and may support the theory of blaNDM emergence from an environmental Acinetobacter.

Corrêa LL ，Kraychete GB ，Rezende AM ，Campana EH ，Lima-Morales D ，Wink PL ，Picão RC ... -  《-》

In Silico Characterization of bla(NDM)-Harboring Conjugative Plasmids in Acinetobacter Species.

Tang B ，Wang C ，Sun D ，Lin H ，Ma J ，Guo H ，Yang H ，Li X ... -  《Microbiology Spectrum》

Whole-genome analysis of New Delhi Metallo-Beta-Lactamase-1-producing Acinetobacter haemolyticus from China.

Infections caused by multidrug-resistant Acinetobacter spp. have generated worldwide attention. With the increasing isolation of non-baumannii Acinetobacter, the nature of associated infection and resistance needs to be explored. This study aimed to analyse the characteristics of New Delhi Metallo-Beta-Lactamase-1 (NDM-1)-producing Acinetobacter haemolyticus (named sz1652) isolated from Shenzhen city, China. The antibiotic spectrum was analysed after antimicrobial susceptibility testing. Combined disk test (CDT) was used to detect the metallo-beta-lactamases (MBLs). Transferability of carbapenem resistance was tested by filter mating experiments and plasmid transformation assays. Whole-genome sequencing (WGS) was performed using HiSeq 2000 and PacBio RS system. The Acinetobacter haemolyticus strain sz1652 was resistant to carbapenems and other tested agents except for amikacin, tigecycline and colistin. Production of MBLs was confirmed by CDT. Transfer of carbapenem resistance was unsuccessful. WGS analysis showed that the genome of sz1652 comprised a chromosome and two plasmids; 16 genomic islands (GIs) were predicted. Genes associated with resistance were found in this strain, including the beta-lactamase genes blaNDM-1, blaOXA-214 and blaLRA-18, the fluoroquinolone resistant-related mutations [GyrA subunits (Ser81Ile) and ParC subunits (Ser84Tyr)], and efflux pump genes related to tetracycline and macrolide resistance. Analysis of the genetic environment showed that blaNDM-1 was embedded in Tn125 transposon. The Tn125 structure was chromosomally located and shared > 99% sequence identity with the previously reported blaNDM-1 carrying region. The NDM-1-producing Acinetobacter haemolyticus coexisted with multiple drug-resistant determinants. The acquisition of the blaNDM-1 gene was probably facilitated by Tn125 in this strain. Non-Acinetobacter baumannii species also contained GIs.

Jiang L ，Yu Y ，Zeng W ，Guo J ，Lv F ，Wang X ，Liu X ，Zhao Z ... -  《-》

Complete sequences of two novel bla (NDM-1)-harbouring plasmids from two Acinetobacter towneri isolates in China associated with the acquisition of Tn125.

Zou D ，Huang Y ，Liu W ，Yang Z ，Dong D ，Huang S ，He X ，Ao D ，Liu N ，Wang S ，Wang Y ，Tong Y ，Yuan J ，Huang L ... -  《Scientific Reports》

Resistome and a Novel bla(NDM-1)-Harboring Plasmid of an Acinetobacter haemolyticus Strain from a Children's Hospital in Puebla, Mexico.

Bello-López E ，Castro-Jaimes S ，Cevallos MÁ ，Rocha-Gracia RDC ，Castañeda-Lucio M ，Sáenz Y ，Torres C ，Gutiérrez-Cazares Z ，Martínez-Laguna Y ，Lozano-Zarain P ... -  《-》