P928 Report of the susceptibility pattern and toxigenicity of Clostridium difficile strains isolated from patients in a tertiary hospital in Greece during four years

S242 handling raw poultry or eating undercooked poultry meat. Many studies have shown an increasing antibiotic resistance among poultry and human strains of Campylobacter. The aim of this study was to compare the prevalence of antimicrobial resistance among C. jejuni and C. coli strains isolated from children with diarrhoea and from chicken meat in central Poland. Methods: All isolates were collected during 2003–2005. Samples of chicken meat were obtained from selected supermarkets in Warsaw. Isolation of Campylobacter sp. from chicken meat was performed according to the ISO10272 guidelines. Campylobacter strains isolated from children with diarrhoea were identified according to the WHO procedure. Species identification was confirmed by the PCR method. Susceptibility to nalidixic acid, ciprofloxacin, tetracycline, erythromycin, gentamycin and ampicilin was determined by the E-test method. Results: A total of 203 Campylobacter sp. strains were isolated. Resistance to tetracycline in all strains did not exceed 30%, but the resistance in chicken isolates increased from 0% in 2003 to 17.3% in 2005 (p < 0.05). Tetracycline had lower activity against human C. jejuni strains comparing to chicken isolates. Ampicillin and ciprofloxacin showed low activity against both C. jejuni and C. coli strains, regardless of their origin. Resistance to ampicillin rose from 8% in 2003 to 35.4% in 2005 (p < 0.05) in human isolates, and from 5.8% to 30.4% in chicken strains (p < 0.05). High rates of ciprofloxacin resistance (>40%) were noted in both human and chicken isolates and they did not change significantly in the study period. Only one human C. jejuni strain was resistant to erythromycin and azithromycin. Resistance to gentamycin was detected in three C. jejuni strains isolated from children and in one chicken strain. Double resistance was detected twice as frequently in child isolates comparing to chicken strains (37% versus 16.7%, respectively). Conclusion: Differences in resistance patterns between human and chicken strains may indicate that chickens are not the main source of Campylobacter infection in Polish children. P927 Ten years of surveillance on antimicrobial resistance in non-typhoidal Salmonella from humans in a Spanish hospital: 1996–2005 C. Rodriguez-Avial, O. L´opez, I. Rodriguez-Avial, J. Picazo (Madrid, ES) Objectives: In the present work we studied the evolution of resistance and the serotypes of nontyphoidal Salmonella isolated during ten years in a hospital of Madrid. Methods: From 1996 thought 2005 a total of 1647 nontyphoidal Salmonella strains were isolated from stools. The identification and susceptibility to 14 antibiotics were performed by a microdilution method (Wyder system). All strains were serotyped using the somatic and flagellar antigens following the Kauffman-White Scheme. Results: Of the 1647 isolates, 25 different serotypes were identified. The most common were S. Enteritidis (76.5%), S. typhimurium (19.5%) and S. Hadar (2%). Overall, 43, 7% of the strains were susceptible to all antibiotics tested. The more relevant antimicrobial resistance rates were: nalidixic-acid (Na) 30, 5%, amoxicilin (A) 22%, chloranphenicol (CL) 9%, gentamycine (G), tobramycin (T) 4, 7%, and cotrimoxazol (SXT) 4.7%. Resistance to Na increased from 13% in 1996 to 38, 5% in 2005. No resistance to ciprofloxacin (CP) was detected, although decreased susceptibility (CMI > 0.12 mg/L) was observed in 89% of Na resistant strains Resistance to CL decreased from 20% in 1996 to 10.5% in 2005 and was associated with S. typhimurium. In 2004 cefoxatime (CTX), ceftazidime (TAZ) and cefoxitin (CX) resistance was observed in four S. Heidelberg strains, all expressed a b-lactamase of pI 8.9 with amplicons showing a high level of homology with CMY-2. The most frequent resistance association was A+ Na (5.5%). Six strains (6 S. typhimurium) were resistant to A+Na+SXT+CL and eleven strains (8 S. typhimurium) to A+SXT+G+CL. Conclusions: S. enteritidis was the most frequent serotype isolated, which showed an increase from 63% in 1996 to 76, 5% in 2005. S. typhimurium was associated with multidrug resistance. Resistance to NA with decreased susceptibility to ciprofloxacin was associated with

17th ECCMID / 25th ICC, Posters S. Enteritidis and S. Hadar serotypes. In 2004 four S. Heidelbeg strains were CMY-2 b-lactamase producers. P928 Report of the susceptibility pattern and toxigenicity of Clostridium difficile strains isolated from patients in a tertiary hospital in Greece during four years M. Orfanidou, H. Kafkoula-Alevizou, E. Vagiakou, H. Tzoumakidou, A. Strouza, H. Malamou-Lada (Athens, GR) Objective: To report the susceptibility pattern and toxigenicity of Clostridium difficile (Cd) strains isolated from hospitalised patients suffering from Cd associated diarrhoea, in a tertiary hospital in Athens, Greece, during four years period (3/02–3/06). Methods: During the study period 2035 stool samples were examined for C.d. using cycloserine cefoxitin fructose agar with 5% egg yolk (CCFA) and cycloserine cefoxitin blood agar (BD). The strains were identified by rapid ANA II (Remel, Lenexa) and latex test (Culturette, BD). Toxin A was detected from C.d. strains by an ELISA (Vidas, bioM´erieux) and a chromatographic assay (ColorPac, BD). Both toxins A&B were detected by an EIA (Premier Toxins A&B, Meridian) and a chromatographic assay (Immunocard Toxins A&B, Meridian). Antibiotic susceptibility testing was performed by E-test (AB Biodisk, Solna). Results: C.d. strains were isolated in 171/2035 (8.4%) stool specimens. Toxin A was detected in 133/171 (77.8%) strains, toxin B in 22/171 (12.9%) and A−B in 16/171 (9.3%) strains. The resistance rate of the isolated C.d. strains to penicillin (PEN) was 78.8% (MICs 0.016->32 mg/L), clindamycin (DA) 55.6% (MICs 0.094->256 mg/L), tetracycline (TE) 33.4% (MICs 0.023−96 mg/L), while no resistance was observed to metronidazole (MTZ) (MICs 0.016–0.38 mg/L), vancomycin (VA) (MICs 0.032−4 mg/L) and piperacillin/tazobactam (TZP) (MICs 0.75−16 mg/L), although one strain presented to VA a high level MIC of 4 mg/L. Especially for meropenem (MP) the resistance rate was 7.6% (MICs 0.016->32 mg/L), while 67 strains were tested also to ertapenem (ERT) and were found to be resistant 20% of them (MICs 0.094>32 mg/L). The MICs range of moxifloxacin (MOX) and erythromycin (ERY) for 80 C.d. strains was found to be 0.25->32 mg/L and 0.125>256 mg/L and their resistance rate was 31.2% and 46% respectively. Linezolid (LZ) was tested in 100 strains and all were found susceptible (MICs 0.5−4 mg/L). All strains that produced toxin B were found resistant to PEN, DA and ERY (MICs 1.5->32 mg/L, >256 mg/L, 12>256 mg/L respectively). Conclusions: – The most common toxin detected remains toxin A but there is an up going presence of toxin B – There is a high resistance rate to PEN, DA, ERY, TE and MOX, while there is still no resistance to MTZ and VA – A new resistance in MP and ERT is being revealed with meropenem being more effective. No resistance was found to LZ. P929 Primary and secondary resistance of Helicobacter pylori to metronidazole and azithromycin in the northern part of Croatia ˇ Z. Maruˇsic, V. Plecko, M. Katicic, L. Zele-Starcevic, A. Budimir, B. Bedenic, A. Presecki Stanko, Z. Boˇsnjak, S. Kalenic (Zagreb, HR) Objectives: The aim of this study was to assess primary and secondary antibiotic resistance rates in Helicobacter pylori isolates over a period of three and a half years (2003–2005 and the first 6 months of 2006). Methods: A total of 378 H. pylori from 347 patients were isolated from 1211 gastric biopsies taken from patients visiting CHC Zagreb and CHC Merkur in Zagreb, Croatia. Isolates from January 1st 2003 to July 1st 2006 were included in the study. From each patient 4 gastric biopsies were taken for histology and 2 were sent to the Department for Clinical and Molecular Microbiology CHC Zagreb for culture and determination of antibiotic activity against H. pylori by means of agar dilution. Susceptibility to clarithromycin, azithromycin, metronidazole, tetracycline and amoxicillin was determined. Primary resistance was