Autor: |
Marasini D; Division of Bacterial Diseases, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Preventiongrid.416738.f, Atlanta, Georgia, USA., Whaley MJ; Division of Bacterial Diseases, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Preventiongrid.416738.f, Atlanta, Georgia, USA., Jenkins LT; Division of Bacterial Diseases, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Preventiongrid.416738.f, Atlanta, Georgia, USA., Hu F; IHRC Inc., Contractor to Division of Bacterial Diseases, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Preventiongrid.416738.f, Atlanta, Georgia, USA., Jiang W; Weems Design Studio, Inc., Contractor to Division of Bacterial Diseases, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Preventiongrid.416738.f, Atlanta, Georgia, USA., Topaz N; Bacterial Meningitis Laboratory, Meningitis and Vaccine Preventable Diseases Branch, Division of Bacterial Diseases, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Preventiongrid.416738.f, Atlanta, Georgia, USA., Chen A; Division of Bacterial Diseases, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Preventiongrid.416738.f, Atlanta, Georgia, USA., Schmink S; Division of Bacterial Diseases, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Preventiongrid.416738.f, Atlanta, Georgia, USA., Dolan Thomas J; Division of Bacterial Diseases, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Preventiongrid.416738.f, Atlanta, Georgia, USA., Harcourt BH; Division of Bacterial Diseases, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Preventiongrid.416738.f, Atlanta, Georgia, USA., Marjuki H; Division of Bacterial Diseases, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Preventiongrid.416738.f, Atlanta, Georgia, USA., Wang X; Division of Bacterial Diseases, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Preventiongrid.416738.f, Atlanta, Georgia, USA. |
Abstrakt: |
To monitor the burden and changes in Haemophilus influenzae (Hi) disease, direct real-time PCR (drt-PCR) assays have been developed for Hi detection in monoplex form and its six serotypes in triplex form, directly from cerebrospinal fluid (CSF) specimens. These assays target the phoB gene for the species detection (Hi- phoB ) and serotype-specific genes in region II of the capsule biosynthesis locus (Hi-abf and Hi-cde), identified through comparative analysis of Hi and non-Hi whole-genome sequences. The lower limit of detection (LLD) is 293 CFU/mL for the Hi- phoB assay and ranged from 11 to 130 CFU/mL for the triplex serotyping assays. Using culture as a reference method, the sensitivity and specificity of Hi- phoB , Hi-abf, and Hi-cde were 100%. Triplex serotyping assays also showed 100% agreement for each serotype compared to their corresponding monoplex serotyping assay. These highly sensitive and specific drt-PCR assays do not require DNA extraction and thereby reduce the time, cost, and handling required to process CSF specimens. Furthermore, triplex drt-PCR assays combine the detection of three serotypes in a single reaction, further improving testing efficiency, which is critical for laboratories that process high volumes of Hi specimens for surveillance and diagnostic purposes. |