title: Molecular survey of beta-lactamases conferring resistance to newer beta-lactams in Enterobacteriaceae isolates from Polish hospitals.
abstract: The first national survey of resistance to newer beta-lactams in nosocomial populations of Enterobacteriaceae in Poland was performed. The study covered all nonrepetitive enterobacterial isolates cultured from specimens from inpatients in 13 regional secondary-care hospitals from November 2003 to January 2004. Among 2,388 isolates, the predominant species was Escherichia coli (59.6%), followed by Proteus mirabilis (14.5%) and Klebsiella spp. (8.5%). The frequency of extended-spectrum beta-lactamases (ESBLs) was very high, with ESBLs present in 11.1% of all isolates and 40.4% of Klebsiella pneumoniae isolates, the latter value greatly exceeding that for E. coli (2.5%). The contribution of outbreak isolates was significant, resulting, for example, in a particularly high rate of ESBL producers among Serratia marcescens isolates (70.8%). The pool of ESBL types was overwhelmingly dominated (81.7%) by CTX-M-like beta-lactamases CTX-M-3 (80.6%) and CTX-M-15, with SHV types (17.5%; SHV-2, SHV-5, and SHV-12) and sporadic TEM-like enzymes (0.7%; TEM-19 and TEM-48) being the next most frequent. Acquired AmpC-type cephalosporinases were observed exclusively in P. mirabilis, in 20.5% of the isolates of this species (compared with the frequency of ESBL producers of 11.5% of P. mirabilis isolates). All these cephalosporinases (CMY-12, CMY-15, and a novel variant, CMY-38) originated from Citrobacter freundii. Four isolates of E. coli (two isolates), K. pneumoniae (one isolate), and P. mirabilis (one isolate) produced class A inhibitor-resistant beta-lactamases (TEM-30, TEM-32, TEM-37, and SHV-49), being the first of such producers identified in Poland. The survey documented both specific and more global characteristics of the epidemiology of the beta-lactamase-mediated resistance in enterobacteria from Polish hospitals and demonstrated that the ESBL frequency has reached an alarming level.
authors.affiliation: National Medicines Institute, 00-725 Warsaw, Poland.
authors.forename: Joanna
authors.initials: J
authors.lastname: Empel
authors.forename: Anna
authors.initials: A
authors.lastname: Baraniak
authors.forename: Elzbieta
authors.initials: E
authors.lastname: Literacka
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Mrówka
authors.forename: Janusz
authors.initials: J
authors.lastname: Fiett
authors.forename: Ewa
authors.initials: E
authors.lastname: Sadowy
authors.forename: Waleria
authors.initials: W
authors.lastname: Hryniewicz
authors.forename: Marek
authors.initials: M
authors.lastname: Gniadkowski
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D003428:Cross Infection / Q000188:drug therapy* / Q000453:epidemiology / Q000382:microbiology*; D003625:Data Collection; D004755:Enterobacteriaceae / Q000187:drug effects* / Q000201:enzymology* / Q000235:genetics / Q000302:isolation & purification; D004756:Enterobacteriaceae Infections / Q000188:drug therapy* / Q000453:epidemiology / Q000382:microbiology*; D005798:Genes, Bacterial; D006801:Humans; D017720:Molecular Epidemiology; D008969:Molecular Sequence Data; D011044:Poland / Q000453:epidemiology; D018440:beta-Lactam Resistance / Q000235:genetics; D001618:beta-Lactamases / Q000096:biosynthesis* / Q000235:genetics; D047090:beta-Lactams / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D047090:beta-Lactams; D001618:beta-Lactamases