Bordetella Detection and Species Identification with the Vivalytic

Cases of Bordetella infections are rising across Europe. Bordetella species are responsible for whooping cough, or pertussis, which literally means violet cough. Vaccine deployment in the 1940s saw a reduction in the morbidity and mortality associated with these infections and now, healthy adults can be expected to make a full recovery. However, vulnerable populations, such as children, the elderly and the immunocompromised, have been shown to be at increased risk of more severe and long-lasting side effects, including increased risk of mortality.

Traditional methods of identifying Bordetella infections take the form of culture, which can take up to 7 days due to the fastidious and slow-growing nature of these bacteria and provide limited sensitivity^1,2. To provide a faster and more sensitive method for the identification of whooping cough pathogens, Randox, in partnership with Bosch, are proud to introduce the Vivalytic Bordetella Cartridge. This real-time PCR assay allows detection of B. pertussis, B. parapertussis and B. holmesii on the Vivalytic system, a universal, fully automated, cartridge-based platform enabling high-plex and low-plex testing, providing an all-in-one solution for molecular diagnostics.

To help you understand the implications of Bordetella infections and those of the Vivalytic system, we have produced a new educational guide, covering the Bordetella species responsible for whooping cough; the pathophysiology and complications associated with these infections; the Vivalytic platform and the benefits it can bring to your laboratory; and finally, a summary of findings presented at ESCMID 2024 in which the Vivalytic Bordetella cartridge showed excellent results. Here, we present this educational guide and a summary of its contents. You can download this guide for free by clicking the download link below.

The Scale of the Bordetella Problem

The rates of positive identification of Bordetella infection are increasing throughout Europe. In England, between January and March 2024, there were 2793 laboratory confirmed cases of whooping cough causing the deaths of 5 infants, compared with a total of 858 cases in 2023³. A rudimentary projection model estimates that without intervention, whooping cough cases in the England could total over 15,000 cases by the end of 2024. Rising cases are not isolated to the UK – increased rates of diagnosis have also been reported in Denmark, Spain, and Croatia⁴. Increased numbers of infections illustrate the need for novel and rapid diagnostics to identify those who have been infected and help reduce the transmission of these bacteria.

Bordetella genus

Bacteria of the Bordetella genus are gram-negative coccobacilli⁵ which are important pathogens in human medicine as they colonise the respiratory tract leading to a range of pulmonary and bronchial infections⁶. There are 3 main species associated with whooping cough: of B. pertussis, B. parapertussis (Classical Bordetella) and B. holmesii (pertussis-like disease pathogen).

Pertussis is caused by Classical Bordetella: B. pertussis and B. parapertussis. Despite widespread vaccination cases are rising, partially due to waning immunity. Pertussis is highly contagious and particularly dangerous for infants, who account for most pertussis-related deaths. The disease progresses through three phases: catarrhal (cold-like symptoms), paroxysmal (severe coughing fits), and convalescent (persistent cough). Classical Bordetella species share over 98% DNA sequence similarity and share many crucial virulence factors like toxins adenylate cyclase toxin (ACT), pertussis toxin (PXT), and dermonecrotic toxin⁵ yet there are variations in potential hosts and disease. For example, B. pertussis is an exclusively human pathogen, whereas B. parapertussis can infect both humans and sheep⁶.

Bordetella holmesii causes pertussis-like symptoms but is ofen less severe. Unlike classical Bordetella, B. holmesii can cause bacteraemia, especially in immunocompromised individuals. Accurate diagnosis of B. holmesii remains challenging due to its similarities with other Bordetella species.

Whooping cough can lead to complications such as pneumonia, which may develop if fever persists beyond the catarrhal phase². CNS complications like seizures and encephalopathy occur in less than 2% of cases, often due to hypoxia, hypoglycaemia, toxins, or secondary infections². Bordetella toxins, especially PXT, increase histamine sensitivity and insulin secretion. Infants are especially at risk of bradycardia, hypotension, and cardiac arrest.

Vivalytic Bordetella Cartridge

To enhance the detection and species identification of Bordetella, Randox introduces the Vivalytic Bordetella cartridge. This user-friendly assay is designed to detect B. pertussis, B. parapertussis, and B. holmesii from a single nasopharyngeal swab or aspirate sample. Utilising Real-time PCR, it enables rapid and accurate detection up to four weeks after symptom onset, differentiating between human pathogenic Bordetella species. With a time to result of just 47 minutes, this assay is invaluable for patient diagnosis and the containment of Bordetella, helping to reduce aerogenic transmission.

Summary of Benefits:

• Sample Volume – 300μl.
• Sample Type – Nasopharyngeal swab sample or aspirates.
• Real-time PCR detection.
• Time to result – ~47 minutes.
• Detection of B. pertussis, B. parapertussis, and B. holmesii.

Rapid and Accurate Detection of Whooping Cough in Clinical Samples

Zimmerman, 2024

At the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) 2024 congress, the Vivalytic Bordetella array showed excellent performance, with a 97.7% concordance and a 97.9% positive percent agreement (PPA) with the reference method.⁷ It accurately identified all additional positive samples and maintained over 98% PPA across spiked samples, even at low levels. The system’s invalid result rate was notably low at 0.6%, compared to 2.9% with the BioGX assay⁷.

The conclusions drawn from this investigation are as follows:

• The Vivalytic Bordetella cartridge provided excellent concordance with a sensitive reference method and delivered fast and accurate results.
• This assay is ideal for both hospital laboratories and outpatient settings, thanks to its user-friendly design and quick turnaround times.
• Early identification of infected patients will aid in preventing the spread of re-emerging whooping cough epidemics.

Conclusion

As Bordetella infections rise across Europe, rapid and accurate detection is crucial. The Vivalytic Bordetella Cartridge offers a fast, reliable solution, identifying B. pertussis, B. parapertussis, and B. holmesii with high accuracy in just 47 minutes. This advanced diagnostic tool can help reduce transmission and manage whooping cough effectively.

Take control of your diagnostic capabilities and ensure the best care for your patients. Download our comprehensive educational guide to learn more about Bordetella infections and the benefits of the Vivalytic system.

For more information on the Vivalytic, the panels mentioned, or any of our products, don’t hesitate to reach out to us at marketing@randox.com.

References

1. Lauria AM, Zabbo CP. Pertussis. StatPearls Publishing; 2024. Accessed June 12, 2024. https://www.ncbi.nlm.nih.gov/books/NBK519008/
2. Pittet LF, Posfay-Barbe KM. Bordetella holmesii: Still Emerging and Elusive 20 Years On. Microbiol Spectr. 2016;4(2). doi:10.1128/microbiolspec.EI10-0003-2015
3. UK Health and Security Agency. Confirmed Cases of Pertussis in England by Month.; 2024.
4. Smout E, Mellon D, Rae M. Whooping cough rises sharply in UK and Europe. BMJ. Published online April 2, 2024:q736. doi:10.1136/bmj.q736
5. Rivera I, Linz B, Harvill ET. Evolution and Conservation of Bordetella Intracellular Survival in Eukaryotic Host Cells. Front Microbiol. 2020;11. doi:10.3389/fmicb.2020.557819
6. Hamidou Soumana I, Linz B, Harvill ET. Environmental Origin of the Genus Bordetella. Front Microbiol. 2017;8. doi:10.3389/fmicb.2017.00028
7. Zimmerman S. Rapid and Accurate Detection of Whooping Cough in Clinical Samples.; 2024.