title: Nosocomial outbreak of KPC-2- and NDM-1-producing Klebsiella pneumoniae in a neonatal ward: a retrospective study.
abstract: The spread of resistance to carbapenems among Enterobacteriaceae has become a major public health problem in recent years. In this study, we describe an outbreak of Klebsiella pneumoniae in the neonatal ward. First, we aimed to study the drug resistance, genetic relatedness, and transmission mechanism of carbapenem-resistant K. pneumoniae; second, we implemented infection control measures to contain the outbreak.
  
  
  
  We investigated 27 non-repetitive strains isolated from neonates and five strains cultured from around the neonatal ward. Polymerase chain reaction (PCR), the agar dilution method, and multilocus sequence typing (MLST) were used to analyze the resistance gene(s), antimicrobial susceptibility, and homology, respectively. Health-care personnel education, hand hygiene, outer gown changing, and infected patient isolation were strictly enforced.
  
  
  
  Our antimicrobial susceptibility results show that all strains were multidrug-resistant. MLST and PCR results revealed that, in this study, all of the KPC-2-producing strains are Sequence Type (ST) 11 (ST11) (n = 22) and all of the NDM-1-producing strains are ST20 (n = 4) or ST888 (n = 1). The environmental strains were identified as KPC-2-positive K. pneumoniae ST11 (n = 3) and NDM-1-positive K. pneumoniae ST20 (n = 2). The percentages of isolates with the extended-spectrum-β-lactamases CTX-M-15, blaCTX-M-14, blaTEM-1 were 9.4, 84.3, and 68.8 %, respectively. AmpC β-lactamase genes were not detected in our isolates.
  
  
  
  KPC-2-positive K. pneumoniae ST11 and NDM-1-positive K. pneumoniae ST20 were associated with this outbreak. The identification of these isolates in samples from radiant warmers and nurses suggests that hospital cross-transmission played a role in this outbreak. Active infection control measures were effective for controlling this multidrug-resistant K. pneumoniae outbreak.
authors.affiliation: Department of Clinical Laboratory, Tongji Hospital, Tongji Medical College Huazhong University of Science and Technology, Jiefang Road 1095#, Wuhan, 430000, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Yu
authors.affiliation: Department of Infection Control, Tongji Hospital, Tongji Medical College Huazhong University of Science and Technology, Jiefang Road 1095#, Wuhan, 430000, China.
authors.forename: Kun
authors.initials: K
authors.lastname: Tan
authors.affiliation: Department of Pediatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Jiefang Road 1095#, Wuhan, 430000, China.
authors.forename: Zhihui
authors.initials: Z
authors.lastname: Rong
authors.affiliation: Department of Clinical Laboratory, Tongji Hospital, Tongji Medical College Huazhong University of Science and Technology, Jiefang Road 1095#, Wuhan, 430000, China.
authors.forename: Yue
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Clinical Laboratory, Tongji Hospital, Tongji Medical College Huazhong University of Science and Technology, Jiefang Road 1095#, Wuhan, 430000, China.
authors.forename: Zhongju
authors.initials: Z
authors.lastname: Chen
authors.affiliation: Department of Clinical Laboratory, Tongji Hospital, Tongji Medical College Huazhong University of Science and Technology, Jiefang Road 1095#, Wuhan, 430000, China.
authors.forename: Xuhui
authors.initials: X
authors.lastname: Zhu
authors.affiliation: Department of Pediatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Jiefang Road 1095#, Wuhan, 430000, China.
authors.forename: Li
authors.initials: L
authors.lastname: Wu
authors.affiliation: Department of Infection Control, Tongji Hospital, Tongji Medical College Huazhong University of Science and Technology, Jiefang Road 1095#, Wuhan, 430000, China.
authors.forename: Li
authors.initials: L
authors.lastname: Tan
authors.affiliation: Department of Infection Control, Tongji Hospital, Tongji Medical College Huazhong University of Science and Technology, Jiefang Road 1095#, Wuhan, 430000, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Xiong
authors.affiliation: Department of Clinical Laboratory, Tongji Hospital, Tongji Medical College Huazhong University of Science and Technology, Jiefang Road 1095#, Wuhan, 430000, China. zysun@tjh.tjmu.edu.
authors.forename: Ziyong
authors.initials: Z
authors.lastname: Sun
authors.affiliation: Department of Pediatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Jiefang Road 1095#, Wuhan, 430000, China. 790356760@qq.com.
authors.forename: Ling
authors.initials: L
authors.lastname: Chen
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000096:biosynthesis / Q000235:genetics; D003428:Cross Infection / Q000175:diagnosis / Q000453:epidemiology* / Q000382:microbiology; D004196:Disease Outbreaks; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007710:Klebsiella Infections / Q000175:diagnosis / Q000453:epidemiology* / Q000382:microbiology; D007711:Klebsiella pneumoniae / Q000235:genetics; D008297:Male; D008826:Microbial Sensitivity Tests; D058885:Multilocus Sequence Typing; D012189:Retrospective Studies; D001618:beta-Lactamases / Q000096:biosynthesis / Q000235:genetics
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D001618:beta-Lactamases; C552864:beta-lactamase NDM-1
keywords: KPC-2; Klebsiella pneumoniae; Multidrug-Resistant; NDM-1; Neonate; Nosocomial Infection