title: Phenotypic and molecular characterization of nosocomial K. pneumoniae isolates by ribotyping.
abstract: OBJECTIVE
  To characterize clinical isolates of Klebsiella pneumoniae by phenotypic and genotypic methods.
  
  
  METHODS
  Over a 12-month period, 52 isolates of K. pneumoniae were isolated. Of these 52 isolates, 7 were isolated over a period of 21 days from a suspected outbreak in the Neonatal Intensive Care Unit (NICU) and 45 from sporadic cases occurring in different wards of hospital were analysed.
  
  
  RESULTS
  The prevalence of K. pneumoniae isolates was 4% (52/1295). Quinolones, aztreonam and amikacin showed the greatest efficacy showing >85% sensitivity. Of the 52 isolates of K. pneumoniae, 8 (15.4%) isolates were positive for ESBL-production. Among the ESBL-producing K. pneumoniae, two out of 8 (25%) and 6 out of 8 (75%) were positive for (bla)SHV and (bla)CTX-M genes respectively. Ribotyping identified 30 distinct ribogroups among 52 isolates evaluated. Seven NICU outbreak isolates were divided into 2 ribotypes, as many as 6 belonged to one ribotype while one isolate which was isolated a week later was of a different ribotype, indicating the termination of the outbreak in the NICU. The outbreak in the NICU thus, was shown to have been caused by a single clone.
  
  
  CONCLUSIONS
  A high discriminatory power, ease of interpretation coupled with excellent reproducibility and stability make ribotyping a very useful technique for investigating the molecular epidemiology of nosocomial infections caused by K. pneumoniae. A regular surveillance of hospital associated infections including monitoring antibiotic sensitivity pattern of K. pneumoniae, ESBL-production and molecular characterization is mandatory to control the spread of multidrug-resistant and ESBL-producing K. pneumoniae and for epidemiological purposes especially in outbreak situations.
authors.affiliation: Department of Medical Laboratory Sciences, College of Medical Sciences, Salman Bin AbdulAziz University, Saudi Arabia. Electronic address: dr.shamweel@sau.edu.sa.
authors.forename: Shamweel
authors.initials: S
authors.lastname: Ahmad
authors.affiliation: Department of Medical Laboratory Sciences, College of Medical Sciences, Salman Bin AbdulAziz University, Saudi Arabia.
authors.forename: Ashraf
authors.initials: A
authors.lastname: Abulhamd
mesh_terms: D000583:Amikacin / Q000494:pharmacology; D001398:Aztreonam / Q000494:pharmacology; D024881:Drug Resistance, Bacterial / Q000235:genetics; D005838:Genotype; D007711:Klebsiella pneumoniae / Q000187:drug effects* / Q000235:genetics; D008826:Microbial Sensitivity Tests; D015363:Quinolones / Q000494:pharmacology; D021521:Ribotyping / Q000379:methods*
chemical_list: D015363:Quinolones; D000583:Amikacin; D001398:Aztreonam
keywords: (bla)(CTX-M); (bla)(SHV); ESBL Production; K. pneumoniae; Multidrug resistance; Multiplex PCR; Ribotyping