title: Carbapenem-resistant strains from the family Enterobacteriaceae isolated in the period 2006-2011 from clinical specimens of patients treated at the university hospital in northeastern Poland.
abstract: BACKGROUND
  In recent years an alarming increase of carbapenem-resistant Enterobacteriaceae has been noticed, which creates frequent therapeutic problems, especially for patients residing in intensive care units (ICU). The aim of this study was to evaluate the prevalence of carbapenem-resistant strains of Enterobacteriaceae isolated in the years 2006-2011 at the University Hospital in Bialystok (UHB).
  
  
  METHODS
  Based on microbiological analysis reports we conducted a retrospective study of strains resistant to carbapenems. We assigned strains to three carbapenem-resistance phenotypes, and analyzed susceptibility to antibiotics and prevalence of these strains in hospital wards and in clinical specimens collected from hospitalized patients. During a six-year period, 216 strains resistant to carbapenems were tested, which represents 0.96% of all Enterobacteriaceae (n = 22.391) isolated during this period.
  
  
  RESULTS
  The greatest number of carbapenem-resistant strains was identified in 2011 (96 strains, 44.44%). Antibiotics that showed the highest activity against strains occurring most frequently (Klebsiella pneumoniae [n = 103] and Enterobacter cloacae [n = 85]) were tigecycline (102 [99.03%] of K. pneumoniae tested strains and 61 [100%] of E. cloacae strains were susceptible), colistin (33 [86.84%] of K. pneumoniae tested strains and 84 [100%] of E. cloacae were susceptible), and amikacin (86 [83.49%] of K. pneumoniae tested strains and 26 [30.58%] of E. cloacae strains were susceptible).
  
  
  CONCLUSIONS
  Carbapenem resistance among Enterobacteriaceae isolates showed a trend to increase during the six-year period of study. Because infections caused by carbapenem-resistant strains are frequently life-threatening, the effective strategies to control the spreading of antibiotic resistance are necessary.
authors.affiliation: Department of Microbiological Diagnostics and Infectious Immunology, Medical University of Białystok, Poland.
authors.forename: Anna Diana
authors.initials: AD
authors.lastname: Michalska
authors.forename: Paweł Tomasz
authors.initials: PT
authors.lastname: Sacha
authors.forename: Dominika
authors.initials: D
authors.lastname: Ojdana
authors.forename: Piotr
authors.initials: P
authors.lastname: Majewski
authors.forename: Piotr
authors.initials: P
authors.lastname: Wieczorek
authors.forename: Elzbieta
authors.initials: E
authors.lastname: Tryniszewska
mesh_terms: D015780:Carbapenems / Q000494:pharmacology*; D003428:Cross Infection / Q000382:microbiology*; D024881:Drug Resistance, Bacterial; D004755:Enterobacteriaceae / Q000145:classification / Q000187:drug effects* / Q000302:isolation & purification*; D006785:Hospitals, University; D006801:Humans; D008826:Microbial Sensitivity Tests; D011044:Poland; D012189:Retrospective Studies; D013045:Species Specificity
chemical_list: D015780:Carbapenems