title: Long-term outbreak ofKlebsiella pneumoniae& third generation cephalosporin use in a neonatal intensive care unit in north India.
abstract: OBJECTIVE
  The indiscriminate use of third generation cephalosporin has contributed to the emergence and widespread dissemination of extended spectrum β lactamases (ESBL) genes in Klebsiella pneumoniae. This study was undertaken to elaborate the genetic behaviour of ESBL - producing K. pneumoniae isolates in the neonatal intensive care unit (NICU) of a tertiary care hospital in north India causing successive outbreaks in context with empirical third generation cephalosporin use.
  
  
  METHODS
  Isolates of K. pneumoniae (43 from blood, 3 from pus and endotracheal tube, 4 from environment) causing successive outbreaks in the NICU of a tertiary care university hospital were studied for two years. Antimicrobial susceptibility testing was done by disc diffusion and minimum inhibitory concentration (MIC) determination by agar dilution methods. ESBL production was determined by phenotypic and genotypic methods. Clonal relatedness among the isolates was studied by enterobacterial repetitive intergenic consensus polymerase chain reaction (ERIC-PCR). Genetic environment of these isolates was assessed by the presence of integrons and gene cassettes. Transformation experiments were done, and plasmids of these isolates were characterized by stability testing and incompatibility testing. Subsequently, a change in the ongoing antibiotic policy was adopted, and corresponding changes in the behaviour of these isolates studied.
  
  
  RESULTS
  During the period from August 2011 to January 2013, 46 isolates of monoclonal ESBL K. pneumoniae were obtained from different neonates and four similar environmental isolates were studied. Multidrug-resistant ESBL isolates harboured both blaCTXM-15 and bla SHV-5. The dfr and aac-6 ' resistant genes were found in gene cassettes. A 50 kb plasmid belonging to IncFIIA group was detected in all the isolates which was transferable and stable. The emergence and regression of the outbreaks coincided with antibiotic usage in the NICU, with widespread empirical use of cefotaxime being responsible for their persistence in the environment.
  
  
  CONCLUSIONS
  The study indicates that empirical use of third generation cephalosporins may promote the emergence, persistence, and dissemination of resistant isolates in the hospital environment. Periodic review of antibiotic policy is necessary for rationalized use of antibiotics.
authors.affiliation: Department of Microbiology, Institute of Medical Sciences, Banaras Hindu University, Varanasi, India.
authors.forename: Tuhina
authors.initials: T
authors.lastname: Banerjee
authors.affiliation: Department of Microbiology, Assam University, Silchar, India.
authors.forename: Amitabha
authors.initials: A
authors.lastname: Bhattacharjee
authors.affiliation: Department of Microbiology, Institute of Medical Sciences, Banaras Hindu University, Varanasi, India.
authors.forename: Supriya
authors.initials: S
authors.lastname: Upadhyay
authors.affiliation: Department of Microbiology, Institute of Medical Sciences, Banaras Hindu University, Varanasi, India.
authors.forename: Shweta
authors.initials: S
authors.lastname: Mishra
authors.affiliation: Department of Microbiology, Institute of Medical Sciences, Banaras Hindu University, Varanasi, India.
authors.forename: Karuna
authors.initials: K
authors.lastname: Tiwari
authors.affiliation: Department of Microbiology, Institute of Medical Sciences, Banaras Hindu University, Varanasi, India.
authors.forename: Shampa
authors.initials: S
authors.lastname: Anupurba
authors.affiliation: Department of Microbiology, Institute of Medical Sciences, Banaras Hindu University, Varanasi, India.
authors.forename: Malay Ranjan
authors.initials: MR
authors.lastname: Sen
authors.affiliation: Department of Pediatrics, Institute of Medical Sciences, Banaras Hindu University, Varanasi, India.
authors.forename: Sriparna
authors.initials: S
authors.lastname: Basu
authors.affiliation: Department of Pediatrics, Institute of Medical Sciences, Banaras Hindu University, Varanasi, India.
authors.forename: Ashok
authors.initials: A
authors.lastname: Kumar
mesh_terms: D002511:Cephalosporins / Q000009:adverse effects / Q000627:therapeutic use; D004196:Disease Outbreaks; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics*; D005838:Genotype; D006801:Humans; D007194:India; D007231:Infant, Newborn; D007363:Intensive Care Units, Neonatal; D007710:Klebsiella Infections / Q000188:drug therapy* / Q000235:genetics / Q000382:microbiology; D007711:Klebsiella pneumoniae / Q000235:genetics* / Q000302:isolation & purification / Q000472:pathogenicity; D062606:Tertiary Care Centers; D001618:beta-Lactamases / Q000235:genetics* / Q000302:isolation & purification
chemical_list: D002511:Cephalosporins; D001618:beta-Lactamases