Application of flow cytometry for the identification of Staphylococcus epidermidis by peptide nucleic acid fluorescence in situ hybridization (PNA FISH) in blood samples

• Published in: Antonie van Leeuwenhoek 2011-10, Vol.100 (3), p.463-470
• Main Authors: Azevedo, N. F., Jardim, T., Almeida, C., Cerqueira, L., Almeida, A. J., Rodrigues, F., Keevil, C. W., Vieira, M. J.
• Format: Article
• Language: English
• Subjects: Bacteria; Bacteriological methods and techniques used in bacteriology; Bacteriology; Biological and medical sciences; Biomedical and Life Sciences; Blood; Blood - microbiology; Cross Infection - diagnosis; Cross Infection - microbiology; Flow cytometry; Flow Cytometry - methods; Fluorescence; Fluorescence in situ hybridization; Fundamental and applied biological sciences. Psychology; Humans; Hybridization; In Situ Hybridization, Fluorescence - methods; Life Sciences; Medical Microbiology; Microbiology; Nosocomial infection; Nosocomial infections; Nucleic acids; Peptide Nucleic Acids - genetics; Plant Sciences; Short Communication; Soil Science & Conservation; Staphylococcal Infections - diagnosis; Staphylococcal Infections - microbiology; Staphylococcus epidermidis - genetics; Staphylococcus epidermidis - isolation & purification
• ISSN: 0003-6072; 1572-9699
• DOI: 10.1007/s10482-011-9595-9

Staphylococcus epidermidis is considered to be one of the most common causes of nosocomial bloodstream infections, particularly in immune-compromised individuals. Here, we report the development and application of a novel peptide nucleic acid probe for the specific detection of S. epidermidis by fluorescence in situ hybridization. The theoretical estimates of probe matching specificity and sensitivity were 89 and 87%, respectively. More importantly, the probe was shown not to hybridize with closely related species such as Staphylococcus aureus . The method was subsequently successfully adapted for the detection of S. epidermidis in mixed-species blood cultures both by microscopy and flow cytometry.