Rapid, Simultaneous Detection ofClostridium sordelliiandClostridium perfringensin Archived Tissues by a Novel PCR-Based Microsphere Assay: Diagnostic Implications for Pregnancy-Associated Toxic Shock Syndrome Cases

Abstract

Clostridium sordelliiandClostridium perfringensare infrequent human pathogens; however, the case-fatality rates for the infections are very high, particularly in obstetricC. sordelliiinfections (>90%). Deaths fromClostridium sordelliiandClostridium perfringenstoxic shock (CTS) are sudden, and diagnosis is often challenging. Formalin-fixed, paraffin-embedded (FFPE) tissues usually are the only specimens available for sudden fatal cases, and immunohistochemistry (IHC) for Clostridia is generally performed but it cannot identify species. A clear need exists for a rapid, species-specific diagnostic assay for FFPE tissues. We developed a duplex PCR-based microsphere assay for simultaneous detection ofC. sordelliiandC. perfringensand evaluated DNA extracted from 42Clostridiumisolates and FFPE tissues of 28 patients with toxic shock/endometritis (20 CTS, 8 non-CTS, as confirmed by PCR and sequencing). The microsphere assay correctly identifiedC. sordelliiandC. perfringensin all known isolates and in all CTS patients (10C. sordellii, 8C. perfringens, 2 both) and showed 100% concordance with PCR and sequencing results. The microsphere assay is a rapid, specific, and cost-effective method for the diagnosis of CTS and offers the advantage of simultaneous testing forC. sordelliiandC. perfringensin FFPE tissues using a limited amount of DNA.