Background: Nucleic acid amplification of the IS481 region by PCR is more sensitive than culture for detection and diagnosis of Bordetella pertussis but the assay has known cross-reactivity for Bordetella holmesii and its use as a routine diagnostic assay has not been widely evaluated.
Methods: The objectives of this study were: 1) to assess the diagnostic utility of real-time IS481 PCR by comparison of results with culture and direct fluorescent antigen (DFA) testing for B. pertussis, 2) to employ a PCR assay designed against a different insertion sequence (IS1001) to assess the incidence of B. holmesii in symptomatic individuals and 3) to design and evaluate a new PCR-based assay which could be used for B. pertussis confirmation. A total of 808 nasopharyngeal specimens were included in the study the majority of which were submitted in charcoal transport medium (88%) with the rest submitted in Regan-Lowe medium.
Results: Concordant results for PCR, DFA and culture were obtained for 21 B. pertussis positive and 729 B. pertussis negative specimens. DFA was prone to false positive and negative reactions when compared with both PCR and culture. The IS481 PCR identified 28 positive results for specimens that were DFA and culture negative. A novel real-time PCR targeting the B. pertussis toxin promoter was found to be specific and useful for confirming the majority of IS481 positive specimens as B. pertussis. B. holmesii was not detected in any of the submitted samples.
Conclusion: The potential pick up of B. holmesii by the IS481 PCR had minimal diagnostic relevance in the Alberta population during the time period of our study. The IS481 PCR assay is now used in our laboratory routinely for front-line screening of samples for B. pertussis with associated enhancement in diagnostic sensitivity compared with DFA and culture. Retrospectively, patients' samples are batched and tested by the IS1001 MB and TPR assays for research purposes and to ensure there is no change in B. holmesii incidence in the population.
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http://dx.doi.org/10.1186/1471-2334-6-62 | DOI Listing |
Microbiol Spectr
December 2024
Department of Pathology, George Washington University School of Medicine and Health Sciences, Washington, DC, USA.
Diagnosis of is made by using polymerase chain reaction (PCR) to detect insertion sequence 481 (IS). However, IS is found in both and . In a recent study, Cole et al.
View Article and Find Full Text PDFJ Clin Microbiol
December 2024
School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, New South Wales, Australia.
Unlabelled: Whooping cough (pertussis) has re-emerged despite high vaccine coverage in Australia and many other countries worldwide, partly attributable to genetic adaptation of the causative organism, to vaccines. Therefore, genomic surveillance has become essential to monitor circulating strains for these genetic changes. However, increasing uptake of PCR for the diagnosis of pertussis has affected the availability of cultured isolates for typing.
View Article and Find Full Text PDFJ Infect
September 2024
Key Laboratory of Major Diseases in Children, Ministry of Education, National Clinical Research Center for Respiratory Diseases, National Key Discipline of Pediatrics, Laboratory of Infection and Microbiology, Beijing Pediatric Research Institute, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing 100045, China. Electronic address:
Microbiol Spectr
August 2024
Division of Parasitic Diseases and Malaria, Global Health Center, Centers for Disease Control and Prevention, Atlanta, Georgia, USA.
Unlabelled: In the United States, the general laboratory method for diagnosing pertussis, caused by is real-time PCR (rt-PCR) targeting insertion sequence 481 (IS). Other species (, and ) can also cause a pertussis-like syndrome, and some commercial laboratory assays include the insertion sequence 1001 (pIS) that can detect /). Because IS exists in and , current commercial assays cannot differentiate these two species.
View Article and Find Full Text PDFDiagn Microbiol Infect Dis
July 2024
Department of Microbiology, National Reference Centre for Bordetella pertussis, Vrije Universiteit Brussel (VUB), Universitair Ziekenhuis Brussel (UZ Brussel), Laarbeeklaan 101, Brussels 1090, Belgium.
Bordetella pertussis is the causative pathogen of whooping cough or pertussis, a contagious respiratory disease. Aside from serodiagnosis, laboratory confirmation of pertussis is done through PCR, as B. pertussis is difficult to culture.
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