Comparison of established diagnostic methodologies and a novel bacterial smpB real-time PCR assay for the specific detection of haemophilus influenzae associated with respiratory tract infections
Reddington, Kate ; Schwenk, Stefan ; Tuite, Nina ; Platt, Gareth ; Davar, Danesh ; Coughlan, Helena ; Personne, Yoann ; Enne, Virve I. ; Zumla, Alimuddin ; Barry, Thomas
Reddington, Kate
Schwenk, Stefan
Tuite, Nina
Platt, Gareth
Davar, Danesh
Coughlan, Helena
Personne, Yoann
Enne, Virve I.
Zumla, Alimuddin
Barry, Thomas
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Publication Date
2015-06-23
Type
Article
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Citation
Kate Reddington, Stefan Schwenk, Nina Tuite, Gareth Platt, Danesh Davar, Helena Coughlan, Yoann Personne, Vanya Gant, Virve I. Enne, Alimuddin Zumla, and Thomas Barry (2015) 'Comparison of established diagnostic methodologies and a novel bacterial smpB real-time PCR assay for the specific detection of Haemophilus influenzae associated with respiratory tract infections'. Journal Of Clinical Microbiology, .
Abstract
Haemophilus influenzae is a significant causative agent of respiratory tract infections (RTI) worldwide. The development of a rapid H. influenzae diagnostic assay that would allow for the implementation of infection control measures and also improve antimicrobial stewardship for patients is required. A number of nucleic acid diagnostics approaches that detect H. influenzae in RTIs have been described in the literature; however, there are reported specificity and sensitivity limitations for these assays. In this study, a novel real-time PCR diagnostic assay targeting the smpB gene was designed to detect all serogroups of H. influenzae. The assay was validated using a panel of well-characterized Haemophilus spp. Subsequently, 44 Haemophilus clinical isolates were collected, and 36 isolates were identified as H. influenzae using a gold standard methodology that combined the results of matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) and a fucK diagnostic assay. Using the novel smpB diagnostic assay, 100% concordance was observed with the gold standard, demonstrating a sensitivity of 100% (95% confidence interval [CI], 90.26% to 100.00%) and a specificity of 100% (95% CI, 63.06% to 100.00%) when used on clinical isolates. To demonstrate the clinical utility of the diagnostic assay presented, a panel of lower RTI samples (n 98) were blindly tested with the gold standard and smpB diagnostic assays. The results generated were concordant for 94/98 samples tested, demonstrating a sensitivity of 90.91% (95% CI, 78.33% to 97.47%) and a specificity of 100% (95% CI, 93.40% to 100.00%) for the novel smpB assay when used directly on respiratory specimens.
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Publisher
American Society for Microbiology
Publisher DOI
10.1128/JCM.00777-15
Rights
Attribution-NonCommercial-NoDerivs 3.0 Ireland