title: Rapid identification, virulence analysis and resistance profiling of Staphylococcus aureus by gene segment-based DNA microarrays: application to blood culture post-processing.
abstract: Up to now, blood culturing systems are the method of choice to diagnose bacteremia. However, definitive pathogen identification from positive blood cultures is a time-consuming procedure, requiring subculture and biochemical analysis. We developed a microarray for the identification of Staphylococcus aureus comprising PCR generated gene-segments, which can reduce the blood culture post-processing time to a single day. Moreover, it allows concomitant identification of virulence factors and antibiotic resistance determinants directly from positive blood cultures without previous amplification by PCR. The assay unambiguously identifies most of the important virulence genes such as tsst-1, sea, seb, eta and antibiotic resistance genes such as mecA, aacA-aphD, blaZ and ermA. To obtain positive signals, 20 ng of purified genomic S. aureus DNA or 2 microg of total DNA extracted from blood culture was required. The microarray specifically distinguished S. aureus from gram-negative bacteria as well as from closely related coagulase negative staphylococci (CoNS). The microarray-based identification of S. aureus can be accomplished on the same day blood cultures become positive in the Bactec. The results of our study demonstrate the feasibility of microarray-based systems for the direct identification and characterization of bacteria from cultured clinical specimens.
authors.affiliation: Institute for Medical Microbiology, Immunology and Hygiene, Medical Center, University of Cologne, Goldenfelsstr. 19-21, 50935 Köln, Germany.
authors.forename: Maria
authors.initials: M
authors.lastname: Palka-Santini
authors.forename: Stefan
authors.initials: S
authors.lastname: Pützfeld
authors.forename: Berit E E
authors.initials: BE
authors.lastname: Cleven
authors.forename: Martin
authors.initials: M
authors.lastname: Krönke
authors.forename: Oleg
authors.initials: O
authors.lastname: Krut
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics*; D015373:Bacterial Typing Techniques; D001769:Blood / Q000382:microbiology; D003470:Culture Media; D004269:DNA, Bacterial / Q000032:analysis / Q000235:genetics; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D005838:Genotype; D006801:Humans; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods*; D016133:Polymerase Chain Reaction / Q000379:methods*; D012680:Sensitivity and Specificity; D013211:Staphylococcus aureus / Q000145:classification* / Q000187:drug effects / Q000235:genetics / Q000472:pathogenicity*; D013997:Time Factors; D014774:Virulence; D037521:Virulence Factors / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D003470:Culture Media; D004269:DNA, Bacterial; D037521:Virulence Factors