title: Outbreak of NDM-1-producing Klebsiella pneumoniae ST76 and ST37 isolates in neonates.
abstract: The purpose of this study was to investigate the epidemiological characteristics of carbapenem-resistant Klebsiella pneumoniae (CRKP) in Shanghai Children's Hospital in China. Twenty-two non-duplicate CRKP strains were collected from pediatric patients between March and June in 2014. Antimicrobial susceptibility testing was conducted by the agar dilution method. Beta-lactamases were characterized by polymerase chain reaction (PCR) and DNA sequencing. The transferability of bla NDM-1 was investigated by conjugation experiment. The plasmids bearing antibiotic resistance genes were characterized by S1 nuclease pulsed-field gel electrophoresis (S1-PFGE) and Southern hybridization. Clonal relatedness was evaluated by PFGE and multilocus sequence typing (MLST). The clinical data of patients were retrospectively reviewed. The 22 CRKP strains were resistant to most of the antimicrobial agents tested, except tigecycline and colistin. Overall, 59, 77, and 100 % of these strains were resistant to imipenem, meropenem, and ertapenem, respectively. The bla NDM-1 was positive in 77.3 % (17/22) of the CRKP strains, of which the 16 isolates from inpatients were designated as ST37 (n = 9) and ST76 (n =7) and one isolate from an outpatient belonged to ST846. The 17 bla NDM-1-positive isolates belonged to PFGE type A (n = 9), type C (n = 7), or type B (n = 1). The plasmids bearing bla NDM-1 could be transferred into recipient Escherichia coli J53 through conjugation in 88.2 % (15/17) of the strains. The hybridization results showed that the plasmids carrying the bla NDM-1 gene were approximately 50-240 kb in size. This is the first report of an outbreak caused by NDM-1-producing K. pneumoniae ST76 and ST37 among neonates.
authors.affiliation: Department of Laboratory Medicine, Shanghai Children's Hospital, Shanghai Jiao Tong University, Lane 24, 1400 W. Beijing Rd., Shanghai, 200040, People's Republic of China.
authors.forename: J
authors.initials: J
authors.lastname: Zhu
authors.affiliation: Institute of Antibiotics, Huashan Hospital, Fudan University, 12 M. Wulumuqi Rd., Shanghai, 200040, People's Republic of China.|Key Laboratory of Clinical Pharmacology of Antibiotics, Ministry of Health, Shanghai, China.
authors.forename: L
authors.initials: L
authors.lastname: Sun
authors.affiliation: Institute of Antibiotics, Huashan Hospital, Fudan University, 12 M. Wulumuqi Rd., Shanghai, 200040, People's Republic of China.|Key Laboratory of Clinical Pharmacology of Antibiotics, Ministry of Health, Shanghai, China.
authors.forename: B
authors.initials: B
authors.lastname: Ding
authors.affiliation: Institute of Antibiotics, Huashan Hospital, Fudan University, 12 M. Wulumuqi Rd., Shanghai, 200040, People's Republic of China.|Key Laboratory of Clinical Pharmacology of Antibiotics, Ministry of Health, Shanghai, China.
authors.forename: Y
authors.initials: Y
authors.lastname: Yang
authors.affiliation: Institute of Antibiotics, Huashan Hospital, Fudan University, 12 M. Wulumuqi Rd., Shanghai, 200040, People's Republic of China.|Key Laboratory of Clinical Pharmacology of Antibiotics, Ministry of Health, Shanghai, China.
authors.forename: X
authors.initials: X
authors.lastname: Xu
authors.affiliation: Department of Laboratory Medicine, Lishui People's Hospital, Lishui, Zhejiang Province, China.
authors.forename: W
authors.initials: W
authors.lastname: Liu
authors.affiliation: Institute of Antibiotics, Huashan Hospital, Fudan University, 12 M. Wulumuqi Rd., Shanghai, 200040, People's Republic of China.|Key Laboratory of Clinical Pharmacology of Antibiotics, Ministry of Health, Shanghai, China.
authors.forename: D
authors.initials: D
authors.lastname: Zhu
authors.affiliation: Institute of Antibiotics, Huashan Hospital, Fudan University, 12 M. Wulumuqi Rd., Shanghai, 200040, People's Republic of China.|Key Laboratory of Clinical Pharmacology of Antibiotics, Ministry of Health, Shanghai, China.
authors.forename: F
authors.initials: F
authors.lastname: Yang
authors.affiliation: Department of Laboratory Medicine, Shanghai Children's Hospital, Shanghai Jiao Tong University, Lane 24, 1400 W. Beijing Rd., Shanghai, 200040, People's Republic of China. zhanghong3010@126.com.
authors.forename: H
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Institute of Antibiotics, Huashan Hospital, Fudan University, 12 M. Wulumuqi Rd., Shanghai, 200040, People's Republic of China. hufupin@163.com.|Key Laboratory of Clinical Pharmacology of Antibiotics, Ministry of Health, Shanghai, China. hufupin@163.com.
authors.forename: F
authors.initials: F
authors.lastname: Hu
mesh_terms: D002648:Child; D002681:China / Q000453:epidemiology; D003227:Conjugation, Genetic; D003428:Cross Infection / Q000453:epidemiology* / Q000382:microbiology; D004196:Disease Outbreaks; D005260:Female; D022761:Gene Transfer, Horizontal; D005838:Genotype; D006776:Hospitals, Pediatric; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007710:Klebsiella Infections / Q000453:epidemiology* / Q000382:microbiology; D007711:Klebsiella pneumoniae / Q000145:classification / Q000201:enzymology* / Q000235:genetics / Q000302:isolation & purification; D008297:Male; D008826:Microbial Sensitivity Tests; D058889:Molecular Typing; D010957:Plasmids / Q000032:analysis; D016133:Polymerase Chain Reaction; D012189:Retrospective Studies; D017422:Sequence Analysis, DNA; D018440:beta-Lactam Resistance; D001618:beta-Lactamases / Q000235:genetics / Q000378:metabolism*
chemical_list: D001618:beta-Lactamases; C552864:beta-lactamase NDM-1