ESBLs, AmpCs & others in Enterobacteriaceae: genes, plasmids & clones – part 2 S333 Conclusion: CMY-2 is the dominant PABL among Norwegian E. coli isolates. It is strongly associated with ISEcp1 upstream and identified on multiple-replicon IncI1, IncA/C or IncFII transferable plasmids. The occurrence of PABLs in Norway is sporadic and is probably linked to globally dispersed uropathogenic strains of CC38, CC448 and ST-131 of which the latter has been associated with the spread of CTX-M-15. P1216 Acquisition of a plasmid carrying blaCMY-2 by the established blaOXA-30-producing Salmonella Typhimurium Iberian clone P. Antunes ° , L. Peixe (Porto, PT) Objectives: Multidrug-resistant (MDR) Salmonella is emerging world- wide, with increasing involvement of particular clones in human infections. Given the importance of cephalosporins in therapeutics, our goal was to characterise mobile genetic elements associated to b-lactams resistance in a predominant MDR Salmonella Typhimurium clone causing foodborne infections in Portugal and Spain over years. Methods: We analysed 46 blaOXA-30-producing Salmonella Ty- phimurium isolates belonging to a previously described Iberian clone obtained from human clinical infections, food products and environment in different regions of Portugal (2002–2008). The isolates were examined for susceptibility to antimicrobial agents and b-lactamase production. Detection of resistance genes and integrases was done by PCR. Class 1 integrons were characterised by PCR, RFLP (TaqI) and sequencing. Clonality was established by PFGE (XbaI). Plasmid analysis included conjugation assays, extraction of DNA and sequencing, determination of size (S1-PFGE) and content (incompatibility groups by rep-PCR typing, hybridisation and sequencing). Location of integron and b-lactamase was performed by hybridisation of I-CeuI/S1-PFGE. Results: The isolates were MDR (predominant phenotype: amoxicillin, chloramphenicol, streptomycin, sulfamethoxazole and tetracycline) and harboured tetB, catA1, sul1, sul2 and blaOXA-30. The integron-borne OXA-30 b-lactamase was located on a conjugative plasmid classified as IncFIIA (140Kb), a common replicon among Salmonella virulence plasmids. Recently, in 2008, we identified from a hospitalised patient with gastrointestinal infection a clinical isolate also carrying the blaCMY-2 gene that was responsible for resistance to most of the large spectrum b-lactams, with exception for cefepime and carbapenems. The blaCMY-2 gene was located on a conjugative IncI1 plasmid of 75kb and analysis of its genetic environment revealed blaCMY-2-blc-sugE genes downstream of a post-segregational killing system (pnd genes). Conclusion: We described for the first time in Portugal the acquisition of a resistance plasmid carrying blaCMY-2 gene by a established MDR blaOXA-30-producing Salmonella Typhimurium clone, conferring resis- tance to therapeutically important broad-spectrum b-lactams. Moreover, the finding of blaCMY-2 gene in a conjugative plasmid IncI1 with a maintenance system is worrisome as persistence of this b-lactamase and its emergence in other Salmonella strains could be anticipated. P1217 Prevalence of ampC b-lactamase genes in Enterobacteriaceae clinical isolates from Aveiro, Portugal S. Ferreira ° , A. Paradela, J. Velez, E. Ramalheira, T. Walsh, S. Mendo (Aveiro, PT; Cardiff, UK) Objectives: AmpC b-lactamases are enzymes that confer resistance to most b-lactams except carbapenems, thus are clinically relevant. The general mechanism for overexpression of chromosomally encoded AmpC b-lactamases is well known, however little is known about the occurrence of plasmid-borne ampC genes. In the present study, we investigated the prevalence of these plasmid encoded genes in clinical isolates collected in Aveiro, Portugal. Methods: Clinical isolates of Escherichia coli (n = 30), Citrobacter freundii (n = 6) and Klebsiella peneumoniae (n = 50) were collected from different inpatients at the Hospital Infante D. Pedro EPE, Aveiro. Strains were selected based on a cefoxitin MIC >16 ug/ml and were tested with Etest (CN/CNI) (AB Biodisk) AmpC strips, according to manufacturer’s instructions. ampC gene families and respective genetic environment were detected by PCR and amplified products were sequenced and compared with others deposited in the GenBank, by standard methods. Results: Two different types of ampC genes were found, blaDHA-1-like in 5 K. pneumoniae and blaCMY-2-like in 6 C. freundii. As expected, all the blaCMY-2-like genes were linked to ISEcp1. blaDHA-1 genes have been found between ISCR1 and 3-CS2 of class 1 integrons in regions of variable length that may include qnrB. Conclusions: Two different types of plasmid borne ampC genes were found among the population studied however, these results can only explain a small proportion of cefoxitin resistant phenotypes. blaCMY- 2-like and blaDHA-1-like genes appeared in genetic contexts similar to those described by other authors. AmpC producers are a major concern in nosocomial infections and should be monitored by surveillance studies. These data highlights the importance of the identification of microorganisms producing plasmid encoded AmpC b-lactamases. P1218 First detection of plasmid-mediated AmpC-type ACC-4 b-lactamase from Proteus mirabilis in Hungary I. Damjanova ° , ´ A. T´ oth, G. Kardos, P. Sz´ antai, P. Orosi, K. B¨ or¨ ocz (Budapest, Debrecen, HU) Objectives: In August 2007 two clinical isolates of Proteus mirabilis showed 3rd generation cephalosprins resistance were isolated at an university teaching hospital and submitted to the National Center for Epidemiology to determine the mechanism of their resistance. Characterisation of these strains was performed. Methods: The two clinical isolates were identified using the Micro- naut E system (Genzyme Virotech GmbH). The MICs of ceftazidime, cefotaxime, cefepime, cefoxitin, imipenem, gentamicin, amikacin and ciprofloxacin were determined by the E-test (AB Biodisk). The phenotypic investigations of mechanism of resistance to cephalosporins were performed by ESBL combined disk test (MAST) and AmpC disk test. The isolates were examined for the presence of bla SHV, blaTEM, blaCTX-M, blaMOX, blaCMY, blaLAT, blaBIL, blaDHA, blaACC, blaMIR, blaACT, blaFOX by PCR and the amplified genes were sequenced. Conjugation and plasmid curing experiments were carried out also. Furthermore typing with pulsed field gel electrophoresis was performed. Results: The isolates were highly resistant to ceftazidime (>256 mg/L), cefotaxime (64 mg/L), gentamicin (128 mg/L), amikacin (>256 mg/L) and ciprofloxacin (>32 mg/L) and moderately resistant to cefoxitin (16−32 mg/L). The ESBL combined disk test did not showed synergy between clavulanic acid and indicator cephalosporins, while the AmpC disk test proved to be positive. According to the PFGE analysis the strains showed identical macrore- striction profiles. The strains carried a large non-transferable plasmid of app. 140 kb in size which was cured from their host. The plasmid cured strains became susceptible to ceftazidime (0.25 mg/L), cefotaxime (0.032 mg/L), gentamicin (1 mg/L) and amikacin (4 mg/L). By PCR screening, the strains were found to be positive for blaACC and blaTEM. Sequence analysis of b-lactamase genes detected blaACC-4 and blaTEM- 1 in both isolates. Conclusion: To our best knowledge this is the first report of plasmid- mediated AmpC-type b-lactamase in Hungary and blaACC-4 in Europe as well as the first blaACC in Proteus mirabilis. P1219 A complex outbreak of multiresistant Enterobacteriaceae producing the acquired AmpC-type b-lactamase FOX-7 in a neonatal intensive care unit setting F. Montagnani, F. Arena, T. Giani, A. Zanchi, M.M. D’Andrea, S. Cresti, G. Zanelli, C. Cellesi, G.M. Rossolini ° (Siena, IT) Background: Enterobacteriaceae are a leading cause of infections in neonatal intensive care units (NICUs). Plasmid-encoded AmpC-type b-lactamases (pACBLs) are resistance determinants of increasing clinical relevance in Enterobacteriaceae. Production of these enzymes is tipically