Development of a Specific and Sensitive Enzyme-Linked Immunosorbent Assay as anIn VitroDiagnostic Tool for Detection ofBartonella henselaeAntibodies in Human Serum
ABSTRACTBartonella henselaecauses cat scratch disease and several other clinical entities. Infections withB. henselaeare frequently occurring; however, the infection is only rarely diagnosed, mainly due to a lack of knowledge in the medical community. Microscopic immunofluorescence assays (IFA) are widely used for the serodiagnosis ofB. henselaeinfections but are laborious and time-consuming, and interpretation is subjective. An easy and reliable method for the serological diagnosis ofB. henselaeinfections is needed to overcome the shortcomings of the current IFA. Here, we report the development of an ELISA detecting human anti-B. henselaeantibodies from serum samples. By separating the water-insoluble fraction ofB. henselaeHouston-1 via ion-exchange chromatography, 16 subfractions were generated and tested for immunoreactivity via line blotting. One particular fraction (fraction 24) was selected and spotted on ELISA plates using an industrial production platform. By use of well-characterized human sera from the strictly quality-controlled serum library of the German National Consiliary Laboratory forBartonellainfections, the sensitivity of this ELISA was 100% for PCR-proven infections and 76% for clinically suspected infections at a specificity of 93%. This ELISA is therefore a reliable high-throughput method allowing the serodiagnosis ofB. henselaeinfections.