Shortened Time to Identify Staphylococcus Species from Blood Cultures and Methicillin Resistance Testing Using CHROMAgar

The ability to rapidly differentiate coagulase-negative staphylococcus (CoNS) from Staphylococcus aureus and to determine methicillin resistance is important as it affects the decision to treat empiric antibiotic selection. The objective of this study was to evaluate CHROMagar S. aureus and CHROMaga...

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Main Authors: Shingo Chihara, Mary K. Hayden, Eileen Minogue-Corbett, Kamaljit Singh
Format: Article
Language:English
Published: Hindawi Limited 2009-01-01
Series:International Journal of Microbiology
Online Access:http://dx.doi.org/10.1155/2009/636502
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spelling doaj-17cb7f1974fc4ce4bb20b1db1db9c3df2021-07-02T18:08:43ZengHindawi LimitedInternational Journal of Microbiology1687-918X1687-91982009-01-01200910.1155/2009/636502636502Shortened Time to Identify Staphylococcus Species from Blood Cultures and Methicillin Resistance Testing Using CHROMAgarShingo Chihara0Mary K. Hayden1Eileen Minogue-Corbett2Kamaljit Singh3Department of Medicine, Section of Infectious Diseases, Rush University Medical Center, 1653 W. Congress Parkway, Chicago, IL 60612, USADepartment of Pathology and Medicine, Section of Infectious Diseases, Rush University Medical Center, 1653 W. Congress Parkway, Chicago, IL 60612, USADepartment of Microbiology, Rush University Medical Center, 1653 W. Congress Parkway, Chicago, IL 60612, USADepartment of Pathology and Medicine, Section of Infectious Diseases, Rush University Medical Center, 1653 W. Congress Parkway, Chicago, IL 60612, USAThe ability to rapidly differentiate coagulase-negative staphylococcus (CoNS) from Staphylococcus aureus and to determine methicillin resistance is important as it affects the decision to treat empiric antibiotic selection. The objective of this study was to evaluate CHROMagar S. aureus and CHROMagar MRSA (Becton Dickinson) for rapid identification of Staphylococcus spp. directly from blood cultures. Consecutive blood culture bottles (BacT Alert 3D SA and SN, bioMérieux) growing gram-positive cocci in clusters were evaluated. An aliquot was plated onto CHROMagar MRSA (C-MRSA) and CHROMagar S. aureus (C-SA) plates, which were read at 12 to 16 hours. C-SA correctly identified 147/147 S. aureus (100% sensitivity); 2 CoNS were misidentified as S. aureus (98% specificity). C-MRSA correctly identified 74/77 MRSA (96% sensitivity). None of the MSSA isolates grew on C-MRSA (100% specificity). In conclusion, CHROMagar is a rapid and sensitive method to distinguish MRSA, MSSA, and coagulase-negative Staphylococcus and may decrease time of reporting positive results.http://dx.doi.org/10.1155/2009/636502
collection DOAJ
language English
format Article
sources DOAJ
author Shingo Chihara
Mary K. Hayden
Eileen Minogue-Corbett
Kamaljit Singh
spellingShingle Shingo Chihara
Mary K. Hayden
Eileen Minogue-Corbett
Kamaljit Singh
Shortened Time to Identify Staphylococcus Species from Blood Cultures and Methicillin Resistance Testing Using CHROMAgar
International Journal of Microbiology
author_facet Shingo Chihara
Mary K. Hayden
Eileen Minogue-Corbett
Kamaljit Singh
author_sort Shingo Chihara
title Shortened Time to Identify Staphylococcus Species from Blood Cultures and Methicillin Resistance Testing Using CHROMAgar
title_short Shortened Time to Identify Staphylococcus Species from Blood Cultures and Methicillin Resistance Testing Using CHROMAgar
title_full Shortened Time to Identify Staphylococcus Species from Blood Cultures and Methicillin Resistance Testing Using CHROMAgar
title_fullStr Shortened Time to Identify Staphylococcus Species from Blood Cultures and Methicillin Resistance Testing Using CHROMAgar
title_full_unstemmed Shortened Time to Identify Staphylococcus Species from Blood Cultures and Methicillin Resistance Testing Using CHROMAgar
title_sort shortened time to identify staphylococcus species from blood cultures and methicillin resistance testing using chromagar
publisher Hindawi Limited
series International Journal of Microbiology
issn 1687-918X
1687-9198
publishDate 2009-01-01
description The ability to rapidly differentiate coagulase-negative staphylococcus (CoNS) from Staphylococcus aureus and to determine methicillin resistance is important as it affects the decision to treat empiric antibiotic selection. The objective of this study was to evaluate CHROMagar S. aureus and CHROMagar MRSA (Becton Dickinson) for rapid identification of Staphylococcus spp. directly from blood cultures. Consecutive blood culture bottles (BacT Alert 3D SA and SN, bioMérieux) growing gram-positive cocci in clusters were evaluated. An aliquot was plated onto CHROMagar MRSA (C-MRSA) and CHROMagar S. aureus (C-SA) plates, which were read at 12 to 16 hours. C-SA correctly identified 147/147 S. aureus (100% sensitivity); 2 CoNS were misidentified as S. aureus (98% specificity). C-MRSA correctly identified 74/77 MRSA (96% sensitivity). None of the MSSA isolates grew on C-MRSA (100% specificity). In conclusion, CHROMagar is a rapid and sensitive method to distinguish MRSA, MSSA, and coagulase-negative Staphylococcus and may decrease time of reporting positive results.
url http://dx.doi.org/10.1155/2009/636502
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