S268 17th ECCMID / 25th ICC, Posters Methods: A total of 264 samples collected from pig, cattle and sheep were screened for A. baumannii. Five clinical isolates were obtained from two Scottish hospitals. Acinetobacter selective medium was used for isolation of this species. Suspected isolates were phenotypically characterised by the API 20NE test, and identification to the species level was carried out by restriction analysis of the 16S-23S rRNA intergenic spacer sequences (RAI16rRNA). The minimum inhibitory concentration of antibiotics was determined by the agar dilution method following the BSAC Guidelines. Pulsed-field gel electrophoresis (PFGE) typing was performed using ApaI restriction endonuclease. Results: Out of 264 animal samples processed, 18 were confirmed as A. baumannii by RAI16rRNA. Two isolates were resistant to ciprofloxacin and two were resistant to gentamicin. All isolates were resistant to ampicillin, trimethoprim, chloramphenicol and tetracycline but were sensitive to imipenem. Dendrogramme analysis showed that most (8 out 9 and 6 out 8) A. baumannii isolated from pig and cattle faecal samples respectively, fell into one major cluster. The clinical isolates grouped in two different clusters and were much more closely related to each other than to those of the animal isolate clusters. Conclusion: This study has shown that PFGE revealed a certain degree of heterogeneity among ciprofloxacin-resistant-A. baumannii from both animal and human isolates, and that they were genetically different. It has also shown that there was no correlation between PFGE profile and ciprofloxacin resistance in both animal and clinical isolates. P1005 Resident OXA-51-like carbapenemases in Acinetobacter baumannii : a useful marker for genotyping? T. Giani, M.M. D’Andrea, R. Migliavacca, M. Spalla, E. Nucleo, G. Fina, F. Luzzaro, L. Pagani, G.M. Rossolini (Siena, Pavia, Varese, IT) Objectives: Multi drug resistant (MDR) Acinetobacter baumannii is a problem of a great concern in nosocomial settings. Hospital outbreaks have been described worldwide and this organism has become endemic in some areas. Comparison of isolates obtained from different investigators is not straightforward, mostly because requires the interchange of isolates between laboratories and the standardisation of the genotyping techniques used. Recently resident blaOXA-51 type determinants have been proposed as a convenient marker for species identification, in alternative to previous molecular approaches. The aim of this study was to investigate the correlation between OXA-51-like carbapenemases and genotypes in a collection of A. baumannii isolates from Italian hospitals. Methods: A. baumannii analyzed in this work included 151 clinical isolates, collected from 14 different Italian hospitals. Identification and susceptibility testing were carried out following standard procedures. Genotyping was carried out by RAPD, REP-PCR and PFGE analysis. OXA-51-like determinants were investigated by PCR, followed by direct amplicon sequencing. Results: Genotyping analysis defined 5 major clusters of MDR A. baumannii, with consistent results using the various typing methods. Each cluster was characterised by a specific resident blaOXA-51- type carbapenemase, namely OXA-66, OXA-69, OXA-90, OXA-98 and OXA-100. The last three are new variants which differ from OXA-51 by 4, 7 and 6 amino acids respectively. Conclusions: Consistent relationship between the blaOXA-51-like variants and genotyping results was found. Present results suggest that OXA-51 typing could be a useful marker for genotyping of A. baumannii clinical isolates. This work was funded in part by the research grant “MIUR-PRIN 2005061894_004”. P1006 Imported cases of carbapenem-resistant Acinetobacter baumannii producing OXA-23 carbapenemase in Belgium: characterisation and unusual loss of resistance P. Bogaerts, T. Naas, C. Bauraing, A. Deplano, D. Pi´ erard, P. Nordmann, Y. Glupczynski (Yvoir, BE; Paris, FR; Brussels, BE) Objectives: International travel contributes to the worldwide spread of multi-drug resistant (MDR) bacterial strains. Carbapenems are the drugs of choice for the treatment of nosocomial infections due to MDR Acinetobacter baumannii (Ab). However, their efficacy is actually compromised through the emergence of carbapenem- hydrolysing b-lactamases (CHBL) in that species. We report here, three independent cases of CHBL OXA-23-producing Ab strains documented after international travel and the unusual spontaneous loss of OXA-23 gene in the absence of any antibiotic treatment. Methods: Over the last 24 months, three severely injured patients were transferred from Cairo (Egypt), Cape Town and Johannesburg (South Africa) to three unrelated hospitals in Belgium. Carbapenem-resistant clinical isolates of Ab were recovered upon patient arrival and for one patient 3 sequential isolates were obtained. The five strains were referred centrally for molecular investigation of their resistance mechanism, using DNA analysis, isoelectric focusing (IEF), conjugation assays and PFGE. BlaIMP, blaVIM, blaOXA-23-like, blaOXA-26-like, blaOXA-51- like, blaOXA-58 genes, blaTEM gene, blaAmpC and the presence of ISAba1 inserted upstream of different genes were sought by PCR. Results: All 5 MDR-Ab isolates were positive blaOXA-51-like and blaAmpC genes and all but one were positive for blaOXA-23-like genes. ISAba1 was detected upstream of blaAmpC, blaOXA-23-like and blaOXA-51-like in 5, 4 and 1 isolates respectively. blaTEM was detected in two isolates. Sequencing of the amplicons revealed identical blaOXA- 23 gene but different blaAmpC and blaOXA-51-like genes. Ab isolates from the different patients were unrelated as shown by PFGE. For one patient with a diagnosis of complicated urinary tract infection, the three consecutive isolates presented identical PFGE patterns, though only the two first isolates were found blaOXA-23-positive. The third isolate was susceptible to carbapenem by loss of the blaOXA-23 gene allowing the patient to be successfully treated by meropenem. Conclusions: Our data further support the role of inter-country transfer in the spread of MDR-Ab and underline the importance of ISAba1 in the expression of b-lactam resistance genes. The spontaneous loss of carbapenem resistance along with blaOXA-23 gene in the absence of antibiotic treatment highlights the importance of judicious and well controlled usage of antibiotics for such MDR isolates. P1007 Plasmid location of blaOXA-40 gene in Acinetobacter baumannii and Acinetobacter haemolyticus S. Quinteira, F. Grosso, L. Peixe (Porto, PT) Objectives: The aim of this work was to investigate the location and genetic background of the carbapenem-hydrolysing oxacillinase gene blaOXA-40 in Acinetobacter spp. isolated from a University Hospital with a high rate of imipenem resistance, mainly due to the endemic presence of the Iberian A. baumannii blaOXA-40 producing clone. Methods: An isolate of A. baumannii and two A. haemolyticus producing OXA-40 recovered from a University Hospital were studied. Susceptibility to antibiotics was determined by standard agar diffusion method and Etest. Carbapenemase producing strains were detected by a bioassay using imipenem discs (10 mg) with enzymatic extracts. Clonality was established by PFGE. The presence and sequencing of blaOXA gene was determined using the blaOXA-24-like primers. Sequencing of flanking regions of blaOXA-40 was conducted in plasmidic extracts. Hybridisation assays were performed using blaOXA-40 probe after S1 nuclease digestion and plasmidic extraction. Furthermore, transfer of resistance by conjugation and transformation assays was also attempted. Results: The A. baumannii and the two A. haemolyticus isolates presented resistance to imipenem, meropenem, ertapenem (MIC of 32 mg/mL), to amoxicillin and its association with clavulanic acid, ure- idopenicillins and their associations (MIC of 256 mg/mL). Resistance to ceftazidime, cefepime and aztreonam (MIC of 256 mg/mL) was only observed in the A. baumannii isolate. Hybridisation experiments with blaOXA-40 probe in S1 nuclease resulting bands and in plasmids extracts revealed a plasmid of about 30 Kb carrying blaOXA-40 in the A. baumannii and the two clonally related A. haemolyticus. These plasmids showed an identical sequence upstream of blaOXA-40.