Avi Peretz1,2, Nina Pastukh3, Natlya Isakovich3, Anna Koifman3, Diana Brodsky3, Hila Mizrahi3, Ilana Aharon4, Kozitta Labay4. 1. Clinical Microbiology Laboratory, Baruch Padeh Medical Center, Poriya, affiliated with the Faculty of Medicine, Bar Ilan University, Galilee, Israel. aperetz@poria.health.gov.il. 2. Unit for Infectious Diseases, Baruch Padeh Medical Center, Poriya, affiliated with the Faculty of Medicine, Bar Ilan University, Galilee, Israel. aperetz@poria.health.gov.il. 3. Clinical Microbiology Laboratory, Baruch Padeh Medical Center, Poriya, affiliated with the Faculty of Medicine, Bar Ilan University, Galilee, Israel. 4. Unit for Infectious Diseases, Baruch Padeh Medical Center, Poriya, affiliated with the Faculty of Medicine, Bar Ilan University, Galilee, Israel.
Abstract
BACKGROUND: Identification of carbapenem-resistant Enterobacteriaceae (CRE) is complex and a major laboratory challenge; clinical cultures may diagnose only some of the CRE carriers among patients, thus it is crucial to perform asymptomatic carriage screening. MATERIALS AND METHODS: We compare the efficacy of a rectal sample culture prior to enrichment with BHI (Brain Heart Infusion) Broth and following 18-24 h. All rectal samples were applied on CHROMagar KPC selective growth media and then seeded on MacConkey agar selective growth media with an applied disk of Imipenem antibiotic on top of the media, then inserted into enrichment BHI Broth. After 18-24 h incubation with enrichment media, all samples were applied again on this media. RESULTS: From the 2,245 rectal samples, CRE colonies were found in 96 (4.3%). Following enrichment with BHI Broth, CRE colonies were found in 111 (4.9%) CHROMagar KPC plates and 106 (4.7%) MacConkey agar. CONCLUSION: We were able to demonstrate that the number of CRE-positive results increased due to use of additional enrichment with BHI Broth. Therefore, we recommend applying this method of addition of liquid enrichment media as part of a culture protocol routine for CRE screening.
BACKGROUND: Identification of carbapenem-resistant Enterobacteriaceae (CRE) is complex and a major laboratory challenge; clinical cultures may diagnose only some of the CRE carriers among patients, thus it is crucial to perform asymptomatic carriage screening. MATERIALS AND METHODS: We compare the efficacy of a rectal sample culture prior to enrichment with BHI (Brain Heart Infusion) Broth and following 18-24 h. All rectal samples were applied on CHROMagar KPC selective growth media and then seeded on MacConkey agar selective growth media with an applied disk of Imipenem antibiotic on top of the media, then inserted into enrichment BHI Broth. After 18-24 h incubation with enrichment media, all samples were applied again on this media. RESULTS: From the 2,245 rectal samples, CRE colonies were found in 96 (4.3%). Following enrichment with BHI Broth, CRE colonies were found in 111 (4.9%) CHROMagar KPC plates and 106 (4.7%) MacConkey agar. CONCLUSION: We were able to demonstrate that the number of CRE-positive results increased due to use of additional enrichment with BHI Broth. Therefore, we recommend applying this method of addition of liquid enrichment media as part of a culture protocol routine for CRE screening.
Authors: Angella Charnot-Katsikas; Vera Tesic; Sue Boonlayangoor; Cindy Bethel; Karen M Frank Journal: J Med Microbiol Date: 2013-11-13 Impact factor: 2.472