title: Prevalence and molecular characterization of Extended Spectrum Beta-Lactamases (ESBLs) producing Escherichia Coli and Klebsiella Pneumoniae.
abstract: The aim of this study was to determine the prevalence of ESBL-producing Escherichia coli and Klebsiella pneumoniae as well as genes encoding ESBLs.
  
  
  METHODS
  A total of 1207 non-repeat isolates of E. coli and K. pneumoniae were obtained from urine, tracheal aspirate, wound swab and blood from patients hospitalized at the University Clinics in Skopje. ESBL set and E-test were used for phenotypic detection of ESBL-production. Multiplex PCR was used to identify genes for different types of ESBLs in 100 ESBL positive strains (E. coli-52 and K. Pneumoniae-48), randomly selected.
  
  
  RESULTS
  Out of 804 E. coli isolates and 403 K. pneumoniae isolates, 126 (15.7%) and 125 (31%) isolates were ESBL producers, respectively. The prevalence of ESBL-positive strains of E. coli in surgery clinics (42 out of total of 211-19.9%) and K. Pneumoniae (61 out of a total of 161-37.9%) was higher compared to those in the clinics of internal medicine (84 out of 593-14.2%) and (64 out of 242-26.4%), respectively. Only 87 of ESBL positive isolates could be typed for one or more genes. Among the isolates of E. coli and K. pneumoniae harbouring a single ESBL gene (39%), blaSHV, blaTEM and blaCTX-M were present in 19.5%, 16% and 3.4% strains, respectively. Two or more genes for ESBL were present in 61% of ESBL isolates; blaTEM+blaSHV being the most common combination.
  
  
  CONCLUSIONS
  The majority of strains harboured two or more ESBL genes and the most common phenotypes were TEM, SHV and CTX-M. Identification of the genes is necessary for the surveillance of their transmission in hospitals.
authors.affiliation: Institute of Microbiology and Parasitology, Medical Faculty  Ss Cyril and Methodius University, Skopje, R. Macedonia.
authors.forename: A
authors.initials: A
authors.lastname: Kaftandzieva
authors.forename: E
authors.initials: E
authors.lastname: Trajkovska-Dokic
authors.forename: N
authors.initials: N
authors.lastname: Panovski
mesh_terms: D003428:Cross Infection / Q000453:epidemiology / Q000382:microbiology; D004269:DNA, Bacterial / Q000032:analysis; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics / Q000302:isolation & purification; D004927:Escherichia coli Infections / Q000453:epidemiology / Q000382:microbiology; D006801:Humans; D007710:Klebsiella Infections / Q000453:epidemiology / Q000382:microbiology; D007711:Klebsiella pneumoniae / Q000201:enzymology / Q000235:genetics / Q000302:isolation & purification; D015995:Prevalence; D018843:Republic of North Macedonia / Q000453:epidemiology; D017422:Sequence Analysis, DNA; D001618:beta-Lactamases / Q000032:analysis
chemical_list: D004269:DNA, Bacterial; D001618:beta-Lactamases