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P564 Prevalence of confirmed ESBL-production among European Enterobacteriaceae: a ten-year report from the SENTRY Antimicrobial Surveillance Program
Extended-spectrum b-lactamases/metallo-b-lactamases Materials and Methods: Cotton swabs were used to obtain surveillance cultures from the hands of 50 healthcare workers attached to Intensive Care Units. Each culture event was performed twice – at the beginning and at the end of their shift. Swabs were placed directly into Mueller– Hinton broth, incubated for 24 hours at 37ºC in ambient air and subsequently subcultured onto blood and Mc Conkey agars followed by 18 to 24 hour-incubation under similar conditions. Initial evaluation of growth was performed by means of Gram stain for each unique colony morphotype present on cultures. Definite bacterial identification and antimicrobial susceptibility testing was achieved with the VITEK 2 identification system. Resistance to imipenem and meropenem was further confirmed by the Etest assay according to the manufacturers’ instructions and data were interpreted by applying the CLSI criteria. Metallo-b-lactamase (MBL) phenotypes among resistant strains were detected with the use of Etest MBL strips. Carbapenemase-resistant isolates were subjected to PCR analysis to confirm the presence of blaVIM and blaIMP genes. Results: During the study, two P. aeruginosa, one P. oryzihabitans and four P. putida non-duplicate isolates were recovered. Among these, one Ps. putida strain was characterised phenotypically as metallo-b-lactamase producer. PCR analysis of the latter with primers for blaVIM genes yielded a 261 bp amplicon, indicating the presence of a blaVIM allele. Interestingly, antimicrobial susceptibility testing revealed one P. aeruginosa strain that showed resistance to imipenem (MIC > 32 ug/mL) and intermediate susceptibility to meropenem (MIC = 8 ug/mL), however MBL production could not be established by both conventional and molecular assays. Conclusion: Previous reports have demonstrated the existence of blaVIM genes in Gram-negative bacilli isolated from various contaminated sites – inanimate objects or intact patient skin surfaces – within hospital facilities. Our study provides further evidence regarding the role of healthcare personnel in multidrug-resistant strains transmission and underlines the need for continuous epidemiological surveillance, in order to assess potential reservoirs, and implementation of preventive policies.
P562 Characterisation of an E. coli strain producer of metallo-b-lactamase in a paediatric hospital R. G´omez-Gil, A. Barrios, J. Mingorance, A. Gutierrez, C. Fern´andez (La Paz, ES) Objective: Characterisation of an E. coli strain producer of metallob-lactamase (MLBs) isolated in hemocultive and urocultives from a patient with acute pielonefritis. Material and Methods: Study of 3 isolates of E. coli from a patient of 20 days of age with acute pielonefritis, obtained first in a hemocultive and urocultive and the third in a new urocultive 4 months later. The identification and sensitivity analyses were done using Wider panels MIC/ID Gram negatives (Soria Melguizo, S.A.® ) and VITEK 2 cards GN and AST-No22 (bioM´erieux® ). Sensitivity to aztreonam was determined by Etest. The MLBs phenotype was settled down with EDTA-imipenem/imipenem Etest and diffusion in Mueler-Hinton agar with an imipenem and EDTA containing disks and with Macfarland 5 inocules. The presence of extended-spectrum b-lactamase (ESBL) was descarded by Etest of cefotaxime/cefotaxime-clavul´anic, ceftazidime/ceftazidime-clavul´anic and cefepime/cefepime-clavulanic. Finally the molecular characterisation was made by ERIC-PCR, and PCR using specific primers (blaVIM, blaIMP) Results: The 3 isolates corresponded to a same strain of E. coli and had an identical antibiotype. The strain presented resistance to all the b-lactamics, except aztreonam with CMI of 0.12 mg/mL. The CMI of imipenem was of 2 mg/mL. The Etest of imipenem/imipenem-EDTA presented a clear inhibition of the metaloenzime over more than 4 dilutions. In addition, there was resistance to gentamicin, tobramicin and trimethoprim-sulfametoxazole. Analyses by PCR showed the presence of a b-lactamase of the VIM family.
S127 Conclusions: In all the isolates of enterobacteriaceae with CMI to imipenem greater of 1 mg/mL, the MLBs should be discarded even if they seem sensible in antibiogram with CLSI cut offs – This is the first description in Spain of metaloenzyme of E. coli in children. – The association of sensitivity and the expression of the phenotype using imipenem/imipenemEDTA with high inocules allows the phenotypical characterisation of the enzyme P563 Beta-lactam resistance mechanisms in clinical isolates of Proteus spp. in Portugal: plasmid-mediated inhibitor resistant TEM and extended-spectrum b-lactamases V. Manageiro, N. Mendon¸ca, D. Louro, E. Ferreira, M. Cani¸ca on behalf of the Antimicrobial Resistance Surveillance Program in Portugal (ARSIP) Objectives: The aim of this study was to evaluate b-lactamase mechanisms responsible for b-lactam resistance in clinical strains of Proteus spp. isolated from hospitals covering several regions of Portugal. The clonal diversity of amoxicillin-resistant (AML-R) isolates of P. mirabilis was also analysed. Methods: During a 6 months period (January to June 1999), 460 consecutive nonduplicate clinical strains of Proteus spp. (429 P. mirabilis, 29 P. vulgaris and 2 P. penneri) were isolated from patients in 16 Portuguese Hospitals and Public Health Institutions. Antibiotic susceptibility tests were performed according to NCCLS and French Society of Microbiology guidelines. ESBL Etest confirmed ESBL production. Isoelectric points of b-lactamases were estimated by isoelectrofocusing. Beta-lactamase resistant genes were searched by PCR-multiplex method and blaTEM genes were identified by nucleotide sequencing, using specific primers. The genetic relatedness among P. mirabilis TEM-producers (n = 42) was investigated by pulsed-field gel electrophoresis (PFGE). Results: AML resistance was observed in 35% of isolates (135 P. mirabilis, 27 P. vulgaris and 1 P. penneri). AML-R P. mirabilis strains were divided in 4 groups: non-TEM producer strains (11%), and penicillinase (86%), IRT-type (2%) and ESBL (1%) producer strains. The coding region of blaTEM genes identified in P. mirabilis revealed that 76% were parental genes (blaTEM-1A, blaTEM-1B, blaTEM-1C, blaTEM-1F or blaTEM-1G), 1% was blaESBL gene (blaTEM-10B), 3% blaIRT-19 genes (blaTEM-74F) and 18% were non-ESBL blaTEM genes. A new gene, named blaTEM-156A, was detected in 3% of P. mirabilis strains. Five different promoter regions were identified among blaTEM genes. Thirty-two PFGE profile types were identified: 26 included clones genetically unrelated and the remaining 6 included clones related/ closely related or undistinguishable (with >80% and 100% similarity, respectively). Conclusion: TEM-1 was the main b-lactamase produced by Proteus spp. associated with the weak promoter P3 in the respective coding gene. TEM-10 enzyme was responsible for the ESBL phenotype and TEM-74 (IRT-19) for the IRT phenotype in P. mirabilis. Antimicrobial resistance to cefuroxime and narrow-spectrum cephalosporins in P. vulgaris and P. penneri were associated with the hyperproduction of cefuroximases. This study emphasizes the need to carefully prescribe b-lactams in infections due to P. mirabilis. P564 Prevalence of confirmed ESBL-production among European Enterobacteriaceae: a ten-year report from the SENTRY Antimicrobial Surveillance Program L. Deshpande, R. Jones, H. Sader, T. Fritsche (North Liberty, US) Objectives: To describe the 10-year trend among European (EUR) Enterobacteriaceae (ENT) isolates displaying phenotypic characteristics of extended-spectrum b-lactamases (ESBL). The global emergence of ESBLs has compromised the activity of penicillins, third- and fourthgeneration cephems and aztreonam (ATM) as empiric agents when treating infections caused by ENT. Understanding of recommended
S128
17th ECCMID / 25th ICC, Posters
ESBL detection criteria is critical for the assessment of isolate susceptibility (S) and initiation of necessary infection control measures. Methods: A total of 30,137 ENT isolates collected from 47 medical centres in 18 EUR countries including Russia, were S tested as part of the SENTRY Antimicrobial Surveillance Program (1997–2006). E. coli (EC), K. pneumoniae (KPN), K. oxytoca (KOX) and P. mirabilis (PM) isolates meeting ESBL-screening criteria (CLSI; MIC values 2 mg/L for ATM or ceftriaxone or ceftazidime) were confirmed using ESBL Etests (AB BIODISK) or the clavulanate (CLA) disk approximation method. A cefepime (FEP) MIC at 4 mg/L was the ESBL screening criterion for Enterobacter spp. (ESP), Citrobacter spp. (CSP) and Serratia spp. (SER) with confirmation performed using FEP with CLA. Results: Among the 26,858 ENT isolates examined for ESBLproduction, 2,954 (11.0%) qualified as potential ESBL producers. A subset of 1,796 were tested using a confirmatory method with 1,359 (75.7%) being positive. Confirmation of screening criteria occurred most frequently (>70%) in KPN, KOX, EC, CSP and least often (<70%) when testing ESP, SER and PM. Among EC and KPN, ESBL-screen positivity rates have increased from 1997–1999 to 2004– 2006 (5.5 to 8.0% and 30.0 to 35.1%, respectively). Occurrence of ESBL-screen positive isolates that did not confirm with CLA inhibition may be attributable to other recognized R mechanisms. Confirmed ESBL-production was often associated with R to fluoroquinolones and aminoglycosides. S to carbapenems, tigecycline, and polymyxin B was retained among ESBL-confirmed isolates.
Organism (no. tested)
ESBL screening criteria results
ESBL confirmatory test results
respective year NCCLS/CLSI documents. A chi-square test was applied to identify differences in each antimicrobial susceptibility rate among the two studied years. P values below 0.05 were considered significant. Results: The same centres participating in both years (n = 19) contributed with the selected ESBL phenotypes and the total Klebsiella spp. isolates for the study (143/279 from 2003 and 93/170 from 2006). Then, 236 Klebsiella spp. ESBL phenotypes clinical isolates entered the analysis. The table presents susceptibility pattern of the Klebsiella spp. ESBL phenotypes according to the year of isolation, the chi-square and the p value for each comparison. Both carbapenems presented elevated susceptibility rates at both years, although a few intermediate and resistant strains occurred. The susceptibility rate for ciprofloxacin did not demonstrate any significant change among the two years. The susceptibility rate for piperacillin/tazobactam in 2003 was 86% and in 2006 61.3%, while the chi-square test yielded a p value <0.0001 for this comparison. Conclusions: The prevalence of isolation of ESBL-producing Klebsiella spp. phenotypes has been stable over the two years in the hospitals evaluated. Stable susceptibility rates were observed among most antimicrobials evaluated in each year against this phenotype, with only the carbapenems presenting virtually full and stable activity. However, susceptibility to piperacillin/tazobactam has decreased significantly over the years, casting doubts on the role of this antimicrobial in empirical therapy for the ESBL-producing phenotypes. Susceptibility pattern of the Klebsiella spp. ESBL phenotypes according to the year of isolation, the chi-square and the p value for each comparison % Susceptibility/year
No. Detected % Positive No. Tested No. (%) Positive EC (15,026) KPN (3,881) KOX (1,121) PM (1,590) ESP (3,369) CSP (683) SER (1,188) Total (26,858)
1,022 1,034 209 171 422 65 31 2,954
6.8 26.6 18.6 10.8 12.5* 9.5* 2.6* 11.0
654 728 96 70 190 15 43 1,796
485 (74.2) 648 (89.0) 80 (83.3) 40 (57.1) 68 (35.8) 11 (73.3) 27 (62.8) 1,359 (75.5)
Ciprofloxacin Piperacillin/tazo Imipenem Meropenem
2003 n = 143
2006 n = 93
73.4 86 99.2 98.3
80.6 61.3 100 99
P value
c2
0.3 <0.0001 0.7 0.7
1.3 17.7 0.18 0.14
*ESBL phenotype screening criterion of FEP 4 mg/L. Conclusions: Among tested EUR ENT, ESBL-screening criteria were most often confirmed among KPN (89.0%) and KOX (83.3%) and less so for EC (74.2%) and other species. ESBL prevalence has increased during this 10-year study, primarily in KPN and EC. Plasmidic movement of ESBLs between ENT species is a likely product of the high prevalence within predominant species, a worrisome development warranting continued longitudinal monitoring. P565 Antimicrobial resistance comparisons amongst extendedspectrum b-lactamase producing Klebsiella spp. phenotypes collected from Brazilian hospitals in 2003 and 2006 C. Mendes, P. Koga, E. Sakagami, P. Turner, C. Kiffer on behalf of the MYSTIC Group Brazil Objective: To compare the antimicrobial resistance rates of extendedspectrum b-lactamase (ESBL) producing Klebsiella spp. phenotypes responsible for hospital infections in two MYSTIC editions (2003 and 2006) in Brazil. Methods: All hospitals participating in both surveillance years were included in the analysis. To be included, the isolates had to be consistent with the definition of an ESBL phenotype, established as having a minimal inhibitory concentration (MIC) to cefotaxime, ceftazidime, and/or cefepime 1.5 mg/mL determined by E-test method. Additionally, MICs were also determined to piperacillin/tazobactam, imipenem, meropenem, and ciprofloxacin. Interpretations followed the
P566 Antibiotic resistance of community-acquired urinary tract infections in south-east Austria. Emergence of E. coli producing extended-spectrum b-lactamase A. Badura, G. Feierl, A. Grisold, L. Masoud, U. Wagner-Eibel, E. Marth (Graz, AT) Objective: To determine antimicrobial resistance rates of the most prevalent Gram-negative pathogens responsible for urinary tract infections in community patients in the region of south-east Austria during the last 5 years (2002 to 2006). Methods: From January 2002 to October 2006, a total of 45.597 urine samples derived from community patients suffering from urinary tract infections from the region of south-east Austria were analysed. Species identification and resistance testing of nonduplicate isolates were done in the routine microbiology laboratory of the Medical University of Graz using conventional methods. Ambiguous results were confirmed with a VITEK 2 system using the ID-GNB or ID-GN test cards (bioM´erieux) for identification and the VITEK 2 AST-N020 test card (bioM´erieux) for resistance testing. Antimicrobial susceptibility results were interpreted using the criteria recommended by CLSI. Production of extendedspectrum b-lactamases (ESBL) was confirmed by the Etest ESBL screen method using strips with cefotaxime, ceftazidime, and cefepime (AB Biodisk, Solna, Sweden). Results: E. coli was most frequently isolated (70%) followed by Proteus spp. (14%), Klebsiella spp. (8%) and Pseudomonas aeruginosa (7%). The proportion of ESBL-producing E. coli increased from 1 isolate (0.03%) in 2002, 5 (0.2%) in 2003, 9 (0.3) in 2004, 27 (0.9%) in 2005 to
P562 Characterisation of an E. coli strain producer of metallo-b-lactamase in a paediatric hospital R. G´omez-Gil, A. Barrios, J. Mingorance, A. Gutierrez, C. Fern´andez (La Paz, ES) Objective: Characterisation of an E. coli strain producer of metallob-lactamase (MLBs) isolated in hemocultive and urocultives from a patient with acute pielonefritis. Material and Methods: Study of 3 isolates of E. coli from a patient of 20 days of age with acute pielonefritis, obtained first in a hemocultive and urocultive and the third in a new urocultive 4 months later. The identification and sensitivity analyses were done using Wider panels MIC/ID Gram negatives (Soria Melguizo, S.A.® ) and VITEK 2 cards GN and AST-No22 (bioM´erieux® ). Sensitivity to aztreonam was determined by Etest. The MLBs phenotype was settled down with EDTA-imipenem/imipenem Etest and diffusion in Mueler-Hinton agar with an imipenem and EDTA containing disks and with Macfarland 5 inocules. The presence of extended-spectrum b-lactamase (ESBL) was descarded by Etest of cefotaxime/cefotaxime-clavul´anic, ceftazidime/ceftazidime-clavul´anic and cefepime/cefepime-clavulanic. Finally the molecular characterisation was made by ERIC-PCR, and PCR using specific primers (blaVIM, blaIMP) Results: The 3 isolates corresponded to a same strain of E. coli and had an identical antibiotype. The strain presented resistance to all the b-lactamics, except aztreonam with CMI of 0.12 mg/mL. The CMI of imipenem was of 2 mg/mL. The Etest of imipenem/imipenem-EDTA presented a clear inhibition of the metaloenzime over more than 4 dilutions. In addition, there was resistance to gentamicin, tobramicin and trimethoprim-sulfametoxazole. Analyses by PCR showed the presence of a b-lactamase of the VIM family.
S127 Conclusions: In all the isolates of enterobacteriaceae with CMI to imipenem greater of 1 mg/mL, the MLBs should be discarded even if they seem sensible in antibiogram with CLSI cut offs – This is the first description in Spain of metaloenzyme of E. coli in children. – The association of sensitivity and the expression of the phenotype using imipenem/imipenemEDTA with high inocules allows the phenotypical characterisation of the enzyme P563 Beta-lactam resistance mechanisms in clinical isolates of Proteus spp. in Portugal: plasmid-mediated inhibitor resistant TEM and extended-spectrum b-lactamases V. Manageiro, N. Mendon¸ca, D. Louro, E. Ferreira, M. Cani¸ca on behalf of the Antimicrobial Resistance Surveillance Program in Portugal (ARSIP) Objectives: The aim of this study was to evaluate b-lactamase mechanisms responsible for b-lactam resistance in clinical strains of Proteus spp. isolated from hospitals covering several regions of Portugal. The clonal diversity of amoxicillin-resistant (AML-R) isolates of P. mirabilis was also analysed. Methods: During a 6 months period (January to June 1999), 460 consecutive nonduplicate clinical strains of Proteus spp. (429 P. mirabilis, 29 P. vulgaris and 2 P. penneri) were isolated from patients in 16 Portuguese Hospitals and Public Health Institutions. Antibiotic susceptibility tests were performed according to NCCLS and French Society of Microbiology guidelines. ESBL Etest confirmed ESBL production. Isoelectric points of b-lactamases were estimated by isoelectrofocusing. Beta-lactamase resistant genes were searched by PCR-multiplex method and blaTEM genes were identified by nucleotide sequencing, using specific primers. The genetic relatedness among P. mirabilis TEM-producers (n = 42) was investigated by pulsed-field gel electrophoresis (PFGE). Results: AML resistance was observed in 35% of isolates (135 P. mirabilis, 27 P. vulgaris and 1 P. penneri). AML-R P. mirabilis strains were divided in 4 groups: non-TEM producer strains (11%), and penicillinase (86%), IRT-type (2%) and ESBL (1%) producer strains. The coding region of blaTEM genes identified in P. mirabilis revealed that 76% were parental genes (blaTEM-1A, blaTEM-1B, blaTEM-1C, blaTEM-1F or blaTEM-1G), 1% was blaESBL gene (blaTEM-10B), 3% blaIRT-19 genes (blaTEM-74F) and 18% were non-ESBL blaTEM genes. A new gene, named blaTEM-156A, was detected in 3% of P. mirabilis strains. Five different promoter regions were identified among blaTEM genes. Thirty-two PFGE profile types were identified: 26 included clones genetically unrelated and the remaining 6 included clones related/ closely related or undistinguishable (with >80% and 100% similarity, respectively). Conclusion: TEM-1 was the main b-lactamase produced by Proteus spp. associated with the weak promoter P3 in the respective coding gene. TEM-10 enzyme was responsible for the ESBL phenotype and TEM-74 (IRT-19) for the IRT phenotype in P. mirabilis. Antimicrobial resistance to cefuroxime and narrow-spectrum cephalosporins in P. vulgaris and P. penneri were associated with the hyperproduction of cefuroximases. This study emphasizes the need to carefully prescribe b-lactams in infections due to P. mirabilis. P564 Prevalence of confirmed ESBL-production among European Enterobacteriaceae: a ten-year report from the SENTRY Antimicrobial Surveillance Program L. Deshpande, R. Jones, H. Sader, T. Fritsche (North Liberty, US) Objectives: To describe the 10-year trend among European (EUR) Enterobacteriaceae (ENT) isolates displaying phenotypic characteristics of extended-spectrum b-lactamases (ESBL). The global emergence of ESBLs has compromised the activity of penicillins, third- and fourthgeneration cephems and aztreonam (ATM) as empiric agents when treating infections caused by ENT. Understanding of recommended
S128
17th ECCMID / 25th ICC, Posters
ESBL detection criteria is critical for the assessment of isolate susceptibility (S) and initiation of necessary infection control measures. Methods: A total of 30,137 ENT isolates collected from 47 medical centres in 18 EUR countries including Russia, were S tested as part of the SENTRY Antimicrobial Surveillance Program (1997–2006). E. coli (EC), K. pneumoniae (KPN), K. oxytoca (KOX) and P. mirabilis (PM) isolates meeting ESBL-screening criteria (CLSI; MIC values 2 mg/L for ATM or ceftriaxone or ceftazidime) were confirmed using ESBL Etests (AB BIODISK) or the clavulanate (CLA) disk approximation method. A cefepime (FEP) MIC at 4 mg/L was the ESBL screening criterion for Enterobacter spp. (ESP), Citrobacter spp. (CSP) and Serratia spp. (SER) with confirmation performed using FEP with CLA. Results: Among the 26,858 ENT isolates examined for ESBLproduction, 2,954 (11.0%) qualified as potential ESBL producers. A subset of 1,796 were tested using a confirmatory method with 1,359 (75.7%) being positive. Confirmation of screening criteria occurred most frequently (>70%) in KPN, KOX, EC, CSP and least often (<70%) when testing ESP, SER and PM. Among EC and KPN, ESBL-screen positivity rates have increased from 1997–1999 to 2004– 2006 (5.5 to 8.0% and 30.0 to 35.1%, respectively). Occurrence of ESBL-screen positive isolates that did not confirm with CLA inhibition may be attributable to other recognized R mechanisms. Confirmed ESBL-production was often associated with R to fluoroquinolones and aminoglycosides. S to carbapenems, tigecycline, and polymyxin B was retained among ESBL-confirmed isolates.
Organism (no. tested)
ESBL screening criteria results
ESBL confirmatory test results
respective year NCCLS/CLSI documents. A chi-square test was applied to identify differences in each antimicrobial susceptibility rate among the two studied years. P values below 0.05 were considered significant. Results: The same centres participating in both years (n = 19) contributed with the selected ESBL phenotypes and the total Klebsiella spp. isolates for the study (143/279 from 2003 and 93/170 from 2006). Then, 236 Klebsiella spp. ESBL phenotypes clinical isolates entered the analysis. The table presents susceptibility pattern of the Klebsiella spp. ESBL phenotypes according to the year of isolation, the chi-square and the p value for each comparison. Both carbapenems presented elevated susceptibility rates at both years, although a few intermediate and resistant strains occurred. The susceptibility rate for ciprofloxacin did not demonstrate any significant change among the two years. The susceptibility rate for piperacillin/tazobactam in 2003 was 86% and in 2006 61.3%, while the chi-square test yielded a p value <0.0001 for this comparison. Conclusions: The prevalence of isolation of ESBL-producing Klebsiella spp. phenotypes has been stable over the two years in the hospitals evaluated. Stable susceptibility rates were observed among most antimicrobials evaluated in each year against this phenotype, with only the carbapenems presenting virtually full and stable activity. However, susceptibility to piperacillin/tazobactam has decreased significantly over the years, casting doubts on the role of this antimicrobial in empirical therapy for the ESBL-producing phenotypes. Susceptibility pattern of the Klebsiella spp. ESBL phenotypes according to the year of isolation, the chi-square and the p value for each comparison % Susceptibility/year
No. Detected % Positive No. Tested No. (%) Positive EC (15,026) KPN (3,881) KOX (1,121) PM (1,590) ESP (3,369) CSP (683) SER (1,188) Total (26,858)
1,022 1,034 209 171 422 65 31 2,954
6.8 26.6 18.6 10.8 12.5* 9.5* 2.6* 11.0
654 728 96 70 190 15 43 1,796
485 (74.2) 648 (89.0) 80 (83.3) 40 (57.1) 68 (35.8) 11 (73.3) 27 (62.8) 1,359 (75.5)
Ciprofloxacin Piperacillin/tazo Imipenem Meropenem
2003 n = 143
2006 n = 93
73.4 86 99.2 98.3
80.6 61.3 100 99
P value
c2
0.3 <0.0001 0.7 0.7
1.3 17.7 0.18 0.14
*ESBL phenotype screening criterion of FEP 4 mg/L. Conclusions: Among tested EUR ENT, ESBL-screening criteria were most often confirmed among KPN (89.0%) and KOX (83.3%) and less so for EC (74.2%) and other species. ESBL prevalence has increased during this 10-year study, primarily in KPN and EC. Plasmidic movement of ESBLs between ENT species is a likely product of the high prevalence within predominant species, a worrisome development warranting continued longitudinal monitoring. P565 Antimicrobial resistance comparisons amongst extendedspectrum b-lactamase producing Klebsiella spp. phenotypes collected from Brazilian hospitals in 2003 and 2006 C. Mendes, P. Koga, E. Sakagami, P. Turner, C. Kiffer on behalf of the MYSTIC Group Brazil Objective: To compare the antimicrobial resistance rates of extendedspectrum b-lactamase (ESBL) producing Klebsiella spp. phenotypes responsible for hospital infections in two MYSTIC editions (2003 and 2006) in Brazil. Methods: All hospitals participating in both surveillance years were included in the analysis. To be included, the isolates had to be consistent with the definition of an ESBL phenotype, established as having a minimal inhibitory concentration (MIC) to cefotaxime, ceftazidime, and/or cefepime 1.5 mg/mL determined by E-test method. Additionally, MICs were also determined to piperacillin/tazobactam, imipenem, meropenem, and ciprofloxacin. Interpretations followed the
P566 Antibiotic resistance of community-acquired urinary tract infections in south-east Austria. Emergence of E. coli producing extended-spectrum b-lactamase A. Badura, G. Feierl, A. Grisold, L. Masoud, U. Wagner-Eibel, E. Marth (Graz, AT) Objective: To determine antimicrobial resistance rates of the most prevalent Gram-negative pathogens responsible for urinary tract infections in community patients in the region of south-east Austria during the last 5 years (2002 to 2006). Methods: From January 2002 to October 2006, a total of 45.597 urine samples derived from community patients suffering from urinary tract infections from the region of south-east Austria were analysed. Species identification and resistance testing of nonduplicate isolates were done in the routine microbiology laboratory of the Medical University of Graz using conventional methods. Ambiguous results were confirmed with a VITEK 2 system using the ID-GNB or ID-GN test cards (bioM´erieux) for identification and the VITEK 2 AST-N020 test card (bioM´erieux) for resistance testing. Antimicrobial susceptibility results were interpreted using the criteria recommended by CLSI. Production of extendedspectrum b-lactamases (ESBL) was confirmed by the Etest ESBL screen method using strips with cefotaxime, ceftazidime, and cefepime (AB Biodisk, Solna, Sweden). Results: E. coli was most frequently isolated (70%) followed by Proteus spp. (14%), Klebsiella spp. (8%) and Pseudomonas aeruginosa (7%). The proportion of ESBL-producing E. coli increased from 1 isolate (0.03%) in 2002, 5 (0.2%) in 2003, 9 (0.3) in 2004, 27 (0.9%) in 2005 to