The study showed that Neisseria species is associated with exacerbation of bronchiectasis in patients

This was discovered by a team of international scientists led by Nanyang Technological University of Singapore (NTU Singapore). Neisseria – a type of bacteria that lives in the human body – is not as harmful as previously thought, and can cause infections in patients with bronchiectasis, asthma and chronic obstructive pulmonary disease (COPD).

In a historical study, published today in host cell and microbe, The team has shown compelling evidence of this Neisseria The species can cause lung disease and is associated with exacerbation of bronchiectasis (a type of lung disease) in patients.

Bronchiectasis is a long-term condition in which the air passages of the lungs become abnormally enlarged for unknown reasons in up to 50 percent of Singaporean patients. The disease is four times more common in Asians than its Western counterparts and can also occur after recovery from tuberculosis. In Singapore, research at Tan Tock Seng Hospital described 420 bronchiectasis patients hospitalized in 2017. The incidence is 10.6 per 100,000 and increases sharply with age.

Despite its prevalence among the elderly, there is no clear cause in most cases of bronchiectasis and the condition tends to appear spontaneously and without warning.

To unravel the mystery of why bronchiectasis worsens at a much greater rate among older Asian patients, the international team – which includes researchers and hospitals in Singapore, Malaysia, China, Australia and the UK – has… (see appendix) Led by LKCMedicine Associate Professor Sanjay Chutermal, University Chair in Molecular Medicine, disease and infection data from 225 patients with bronchiectasis of Asian origin (Singapore and Malaysia) matched to bronchiectasis patients in Europe.

Neisseria: Not harmful after all

While Neisseria The species is known to cause meningitis and gonorrhea, and is not known to infect the lungs. Through detailed identification and careful characterization, the research team found that Neisseria The microbiome of Asian patients with exacerbations of bronchiectasis was controlled.

Specifically, patients with bronchiectasis predominate in amounts from a subgroup of Neisseria Call Neisseria subflava (N. subflava), suffer from more severe disease and frequent infection (exacerbations) when compared to patients with bronchiectasis without such high amounts of Neisseria.

After further investigations using experimental cells and animal models, the research team confirmed this N. subflava It causes cell disruption, leading to inflammation and immune dysfunction in bronchiectasis patients with these bacteria.

Prior to this discovery, Neisseria was not considered to be a cause of lung infection or severe disease in bronchiectasis patients.

Lead researcher Professor Chottermal of LKCMedicine said, “Our findings demonstrate, for the first time, that poorer clinical outcomes such as disease severity, poor lung function, and higher rates of recurrent infections among bronchiectasis patients are closely related to Neisseria bacteria and that this finding is significant. Especially for Asian patients.”

“This discovery is important because it could change the way we treat bronchiectasis patients with this bacteria. Doctors will now need to consider Neisseria as a potential ‘causative’ for patients who get worse despite treatment, and run tests to identify those who may harbor this type of bacteria in their We hope that early identification with personalized treatment will lead to better satisfactory outcomes for Asian patients with this devastating disease,” said Professor Schuttermal, who is also Associate Dean (faculty affairs) at LKCM Medical.

This study reflects NTU’s efforts under NTU2025, the university’s five-year strategic plan that addresses humanity’s major challenges such as human health. The study was conducted by international researchers from various disciplines, and also highlights the strength of the NTU and its focus on interdisciplinary research.

Wider significance of Neisseria

Aside from linking Neisseria and acute bronchiectasis, the NTU-led research team also discovered the same bacteria in other, more common chronic respiratory conditions such as severe asthma and chronic obstructive pulmonary disease (COPD) — a condition that causes airflow and breathing obstruction. Related problems.

Using next-generation sequencing techniques, the team also sought to verify the source of this bacteria and to take samples from the homes of bronchiectasis patients who had large amounts of Neisseria in their lungs. The researchers found the presence of bacteria in the home environment, suggesting that an indoor living space and possibly a tropical climate might favor the presence of these bacteria in the Asian environment.

What is Neisseria?

The Neisseria Bacteria species have been identified as the cause of sexually transmitted infections such as gonorrhea but also serious meningitis – an infection of the fluid and membranes surrounding the brain and spinal cord. Its subtypes N. subflavaHowever, it is known to be present in the oral mucosa, throat, and upper airway of humans previously without any known connection to lung infections.

This family of bacteria has long been thought to be harmless to humans, and the infection that causes it has not been described – until now.

It is encouraging to see that we have made progress in identifying Neisseria species as a cause of exacerbation of bronchiectasis, an unlikely culprit that was not originally considered a threat. This comes as a powerful reminder that we shouldn’t get too complacent when it comes to doing research and being more proactive in exploring different possibilities, where every seemingly innocent ingredient can be a threat to our bodies and our health in general.”

Wang De Yun, Co-author, Professor, Department of Otolaryngology, Yong Lo Lin School of Medicine, National University of Singapore

Co-author Andrew Tan, Associate Professor of Metabolic Disorders from LKCMedicine, said, “The reverse translational approach adopted in this work has been critical to our success. Starting at the ‘bed’ where we studied patients’ real-life experiences, we then worked backwards to reveal the biological process of the bacteria. Thanks to the interdisciplinary nature of the study, the team was able to interact with members of different research disciplines, providing an enjoyable experience while gaining unique insights into the disease.”

The researchers are now looking forward to further studies and clinical trials of Neisseria Eradication of the microbiome by the newly launched LKCM Center for Microbiome Medicine, which seeks to assess the benefits of targeting and treatment Neisseria Using antibiotics at the first discovery, in the hope that it will lead to better clinical outcomes for patients with chronic respiratory diseases.


Journal reference:

night. et al. (2022) Neisseria species as pathogens in bronchiectasis. Host cell and microbe.