title: Plasmid-mediated AmpC: prevalence in community-acquired isolates in Amsterdam, the Netherlands, and risk factors for carriage.
abstract: OBJECTIVE
  The objective of this study was to determine the prevalence of pAmpC beta-lactamases in community-acquired Gram negative bacteria in the Netherlands, and to identify possible risk factors for carriage of these strains.
  
  
  METHODS
  Fecal samples were obtained from community-dwelling volunteers. Participants also returned a questionnaire for analysis of risk factors. Screening for pAmpC was performed with selective enrichment broth and a selective screening agar. Confirmation of AmpC-production was performed with two double disc combination tests: cefotaxime and ceftazidime with either boronic acid or cloxacillin as inhibitor. Multiplex PCR was used as gold standard for detection of pAmpC. 16S rRNA PCR and AFLP were performed as required, plasmids were identified by PCR-based replicon typing. Questionnaire results were analyzed with SPSS, version 20.0.
  
  
  RESULTS
  Fecal samples were obtained from 550 volunteers; mean age 51 years (range: 18-91), 61% were females. pAmpC was present in seven E. coli isolates (7/550, 1.3%, 0.6-2.7 95% CI): six CMY-2-like pAmpC and one DHA. ESBL-encoding genes were found in 52/550 (9.5%, 7.3-12.2 95% CI) isolates; these were predominantly blaCTX-M genes. Two isolates had both ESBL and pAmpC. Admission to a hospital in the previous year was the only risk factor we identified.
  
  
  CONCLUSIONS
  Our data indicate that the prevalence of pAmpC in the community seems still low. However, since pAmpC-producing isolates were not identified as ESBL producers by routine algorithms, there is consistent risk that further increase of their prevalence might go undetected.
authors.affiliation: Medical Microbiology and Infection Control, VU University Medical Center, Amsterdam, The Netherlands.
authors.forename: E Ascelijn
authors.initials: EA
authors.lastname: Reuland
authors.affiliation: Laboratory for Medical Microbiology and Public Health, Hengelo, The Netherlands.
authors.forename: Teysir
authors.initials: T
authors.lastname: Halaby
authors.affiliation: Department of Medical Microbiology and Infectious Diseases, Erasmus MC, Rotterdam, The Netherlands.
authors.forename: John P
authors.initials: JP
authors.lastname: Hays
authors.affiliation: Department of Medical Microbiology and Infectious Diseases, Erasmus MC, Rotterdam, The Netherlands.
authors.forename: Denise M C
authors.initials: DM
authors.lastname: de Jongh
authors.affiliation: Medical Microbiology and Infection Control, VU University Medical Center, Amsterdam, The Netherlands.
authors.forename: Henrieke D R
authors.initials: HD
authors.lastname: Snetselaar
authors.affiliation: Medical Microbiology and Infection Control, VU University Medical Center, Amsterdam, The Netherlands.
authors.forename: Marte
authors.initials: M
authors.lastname: van Keulen
authors.affiliation: EMGO Institute for Health and Care Research, VU University Medical Center, Amsterdam, The Netherlands.
authors.forename: Petra J M
authors.initials: PJ
authors.lastname: Elders
authors.affiliation: Medical Microbiology and Infection Control, VU University Medical Center, Amsterdam, The Netherlands.
authors.forename: Paul H M
authors.initials: PH
authors.lastname: Savelkoul
authors.affiliation: Medical Microbiology and Infection Control, VU University Medical Center, Amsterdam, The Netherlands.
authors.forename: Christina M J E
authors.initials: CM
authors.lastname: Vandenbroucke-Grauls
authors.affiliation: Medical Microbiology and Infection Control, VU University Medical Center, Amsterdam, The Netherlands; Laboratory for Medical Microbiology and Public Health, Hengelo, The Netherlands; Medical Microbiology and Infection Control, Ziekenhuisgroep Twente, Almelo, The Netherlands.
authors.forename: Nashwan
authors.initials: N
authors.lastname: Al Naiemi
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D054458:Amplified Fragment Length Polymorphism Analysis; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000032:analysis* / Q000235:genetics; D002439:Cefotaxime / Q000494:pharmacology; D002442:Ceftazidime / Q000494:pharmacology; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics; D005243:Feces / Q000737:chemistry*; D005260:Female; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D012307:Risk Factors; D055815:Young Adult; D001618:beta-Lactamases / Q000032:analysis* / Q000235:genetics
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D002442:Ceftazidime; C048795:AmpC beta-lactamases; D001618:beta-Lactamases; D002439:Cefotaxime