title: Characterization and plasmid elimination of NDM-1-producing Acinetobacter calcoaceticus from China.
abstract: The presence of multidrug-resistant bacterial pathogens in the environment poses a serious threat to public health. The opportunistic Acinetobacter spp. are among the most prevalent causes of nosocomial infections. Here, we performed complete genome sequencing of the Acinetobacter calcoaceticus strain XM1570, which was originally cultivated from the sputum of a patient diagnosed with pneumonia in Xiamen in 2010. We identified carbapenem resistance associated gene bla(NDM-1) located on a 47.3-kb plasmid. Three methods--natural reproduction, sodium dodecyl sulfate treatment and nalidixic acid treatment--were used to eliminate the bla(NDM-1)-encoding plasmid, which achieved elimination rates of 3.32% (10/301), 83.78% (278/332), and 84.17% (298/354), respectively. Plasmid elimination dramatically increased antibiotic sensitivity, reducing the minimum bacteriostatic concentration of meropenem from 256 µg/ml in the clinical strain to 0.125 µg/ml in the plasmid-eliminated strain. Conjugation transfer assays showed that the bla(NDM-1)-containing plasmid could be transferred into Escherichia coli DH5α:pBR322 in vitro as well as in vivo in mice. The bla(NDM-1) genetic environment was in accordance with that of other bla(NDM-1) genes identified from India, Japan, and Hong-Kong. The multilocus sequence type of the isolate was identified as ST-70. Two novel genes encoding intrinsic OXA and ADC were identified and named as OXA-417 and ADC-72. The finding of bla(NDM-1) in species like A. calcoaceticus demonstrates the wide spread of this gene in gram-negative bacteria which is possible by conjugative plasmid transfer. The results of this study may help in the development of a treatment strategy for controlling NDM-1 bacterial infection and transmission.
authors.affiliation: Institute of Military Veterinary, AMMS, Key Laboratory of Jilin Province for Zoonosis Prevention and Control, Changchun, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Sun
authors.affiliation: Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Liu
authors.affiliation: Institute of Military Veterinary, AMMS, Key Laboratory of Jilin Province for Zoonosis Prevention and Control, Changchun, China.
authors.forename: Shuo
authors.initials: S
authors.lastname: Chen
authors.affiliation: Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Song
authors.affiliation: Institute of Military Veterinary, AMMS, Key Laboratory of Jilin Province for Zoonosis Prevention and Control, Changchun, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Liu
authors.affiliation: Institute of Military Veterinary, AMMS, Key Laboratory of Jilin Province for Zoonosis Prevention and Control, Changchun, China.
authors.forename: Xuejun
authors.initials: X
authors.lastname: Guo
authors.affiliation: Institute of Military Veterinary, AMMS, Key Laboratory of Jilin Province for Zoonosis Prevention and Control, Changchun, China.
authors.forename: Lingwei
authors.initials: L
authors.lastname: Zhu
authors.affiliation: Institute of Military Veterinary, AMMS, Key Laboratory of Jilin Province for Zoonosis Prevention and Control, Changchun, China.
authors.forename: Xue
authors.initials: X
authors.lastname: Ji
authors.affiliation: Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, China.
authors.forename: Lizhi
authors.initials: L
authors.lastname: Xu
authors.affiliation: Institute of Military Veterinary, AMMS, Key Laboratory of Jilin Province for Zoonosis Prevention and Control, Changchun, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Zhou
authors.affiliation: Institute of Military Veterinary, AMMS, Key Laboratory of Jilin Province for Zoonosis Prevention and Control, Changchun, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Qian
authors.affiliation: Institute of Military Veterinary, AMMS, Key Laboratory of Jilin Province for Zoonosis Prevention and Control, Changchun, China.
authors.forename: Shuzhang
authors.initials: S
authors.lastname: Feng
mesh_terms: D000151:Acinetobacter Infections / Q000188:drug therapy / Q000382:microbiology; D016954:Acinetobacter calcoaceticus / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification; D000818:Animals; D001426:Bacterial Proteins / Q000096:biosynthesis / Q000235:genetics*; D002510:Cephalosporinase / Q000235:genetics; D002681:China; D003227:Conjugation, Genetic; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics; D016680:Genome, Bacterial; D006801:Humans; D008297:Male; D051379:Mice; D010957:Plasmids / Q000235:genetics; D018410:Pneumonia, Bacterial / Q000188:drug therapy / Q000382:microbiology; D014774:Virulence / Q000235:genetics; D001618:beta-Lactamases / Q000096:biosynthesis / Q000235:genetics*
chemical_list: D001426:Bacterial Proteins; D002510:Cephalosporinase; D001618:beta-Lactamases; C552864:beta-lactamase NDM-1; C108449:oxacillinase