Article
Immunology
Sara E. Oliver, Amy B. Rubis, Heidi M. Soeters, Arthur Reingold, Meghan Barnes, Susan Petit, Monica M. Farley, Lee H. Harrison, Kathy Como-Sabetti, Sarah A. Khanlian, Rachel Wester, Ann Thomas, William Schaffner, Henju Marjuki, Xin Wang, Susan Hariri
Summary: This study evaluated the epidemiology of NTHi disease in the US, including among pregnant women, infants, and PWH. Results showed that NTHi causes substantial invasive disease, especially among older adults, pregnant/postpartum women, and neonates. Enhanced surveillance and targeted interventions are needed to prevent perinatal NTHi infections.
CLINICAL INFECTIOUS DISEASES
(2023)
Article
Multidisciplinary Sciences
Nadia A. Kadry, Eric A. Porsch, Hao Shen, Joseph W. St Geme
Summary: NTHi is a common cause of respiratory tract disease and preventing colonization is a strategy to prevent disease. Immunization with HMW1 and HMW2 can protect against colonization by both parent NTHi strain and heterologous strains expressing distinct HMW1 and HMW2 proteins. The protection against heterologous strains is IL-17A dependent.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2021)
Article
Immunology
Natalie R. Lindgren, Lea Novak, Benjamin C. Hunt, Melissa S. McDaniel, W. Edward Swords
Summary: Patients with cystic fibrosis (CF) commonly experience lifelong respiratory infections. This study found that initial colonization with non-typeable Haemophilus influenzae (NTHi) reduces susceptibility to subsequent Pseudomonas aeruginosa (P. aeruginosa) infection in the respiratory tract, likely due to the priming of host innate immunity.
INFECTION AND IMMUNITY
(2022)
Article
Microbiology
Benjamin C. Hunt, Xin Xu, Amit Gaggar, W. Edward Swords
Summary: This study found that thiol-mediated redox homeostasis is a key determinant of the persistence of nontypeable Haemophilus influenzae (NTHi) within biofilm communities in smoke-exposed individuals.
Article
Microbiology
Benjamin C. Hunt, Xin Xu, Amit Gaggar, W. Edward Swords
Summary: Smoke exposure is a risk factor for community-acquired pneumonia, and redox homeostasis plays a crucial role in the persistence of NTHi within biofilm communities.
Article
Microbiology
Timothy F. Murphy, Charmaine Kirkham, Adonis D'Mello, Sanjay Sethi, Melinda M. Pettigrew, Herve Tettelin
Summary: Chronic obstructive pulmonary disease (COPD) is a common and debilitating disorder that is the third leading cause of death worldwide. This study analyzed the persistence of nontypeable Haemophilus influenzae (NTHi) in COPD airways and found that the NTHi genome undergoes inversion during persistence, resulting in changes in expression of key virulence factors. It was also discovered that the adhesins HMW1 and HMW2 play a critical role in NTHi adherence and invasion of respiratory epithelial cells. These findings provide important insights into the mechanisms of NTHi persistence in COPD airways and may inform the development of novel interventions.
Article
Microbiology
Stephen C. Watts, Louise M. Judd, Rosemary Carzino, Sarath Ranganathan, Kathryn E. Holt
Summary: Respiratory infection during childhood is a key risk factor in early cystic fibrosis lung disease progression. Haemophilus influenzae and Haemophilus parainfluenzae are commonly isolated from the lungs of children with CF, with a high frequency of colonization and antimicrobial resistance. The genetic basis for AMR in these bacteria was identified, and Haemophilus parainfluenzae had a higher prevalence of acquired AMR genes than H. influenzae.
Article
Pediatrics
Grigorios Chatziparasidis, Ahmad Kantar, Keith Grimwood
Summary: The respiratory tract antimicrobial defense system protects the lungs from microorganisms through various defense mechanisms. Nontypeable Haemophilus influenzae (NTHi), a potential pathogen, uses multiple strategies to colonize the lower airways and establish persistent infections. NTHi impairs mucociliary clearance, evades host defenses, and forms biofilms, causing chronic infections and inflammation. Understanding the molecular pathogenesis of NTHi is important for developing effective therapies and vaccines, considering its genetic heterogeneity. Currently, there are no vaccine candidates ready for large clinical trials.
PEDIATRIC PULMONOLOGY
(2023)
Review
Microbiology
Bryn Short, Stephen Carson, Anna-Claire Devlin, James A. Reihill, Anne Crilly, William MacKay, Gordon Ramage, Craig Williams, Fionnuala T. Lundy, Lorcan P. McGarvey, Keith D. Thornbury, S. Lorraine Martin
Summary: Haemophilus influenzae is a common cause of bacterial infection in the lungs of COPD patients, leading to acute exacerbations. Its ability to adhere to host epithelial cells, form biofilms, and persist through immune evasion and antibiotic tolerance plays a crucial role in the pathogenesis of COPD.
CRITICAL REVIEWS IN MICROBIOLOGY
(2021)
Article
Immunology
Rika Nakahashi-Ouchida, Hiromi Mori, Yoshikazu Yuki, Shingo Umemoto, Takashi Hirano, Yohei Uchida, Tomonori Machita, Tomoyuki Yamanoue, Shin-ichi Sawada, Masashi Suzuki, Kohtaro Fujihashi, Kazunari Akiyoshi, Yuichi Kurono, Hiroshi Kiyono
Summary: A nasal vaccine containing the NTHi surface antigen P6 was developed, which effectively induced specific IgA antibodies and prevented NTHi colonization and biofilm formation, providing protection against infection in mice.
FRONTIERS IN IMMUNOLOGY
(2022)
Article
Microbiology
Emi Tanaka, Takeaki Wajima, Kei-Ichi Uchiya, Hidemasa Nakaminami
Summary: This study investigates the emergence and dissemination mechanisms of low susceptibility to quinolones in Haemophilus influenzae strains. The results show that quinolone resistance can emerge through point mutation in gyrA as well as through horizontal transfer of mutated gyrA. Additionally, extracellular DNA plays an active role in the transfer of quinolone resistance. The study also identifies specific sequences involved in the horizontal transfer of resistance. These findings highlight the importance of monitoring drug resistance in H. influenzae isolates.
ANTIMICROBIAL AGENTS AND CHEMOTHERAPY
(2022)
Article
Microbiology
Anna Carrera-Salinas, Aida Gonzalez-Diaz, Rachel L. Ehrlich, Damaris Berbel, Fe Tubau, Xavier Pomares, Junkal Garmendia, M. Angeles Dominguez, Carmen Ardanuy, Daniel Huertas, Alicia Marin, Conchita Monton, Joshua Chang Mell, Salud Santos, Sara Marti
Summary: The immunomodulatory properties of azithromycin reduce the frequency of exacerbations and improve the quality of life of COPD patients. However, long-term administration may alter the respiratory microbiota, such as Haemophilus influenzae, an opportunistic respiratory colonizing bacteria that play an important role in exacerbations. This study contributes to a better understanding of COPD progression by characterizing the clinical evolution of H. influenzae in a cohort of patients with prolonged azithromycin treatment. The emergence of macrolide resistance during the first months, combined with the role of Haemophilus parainfluenzae as a reservoir and source of resistance dissemination, is a cause for concern that may lead to therapeutic failure. Furthermore, genetic variations in cell wall and inorganic ion metabolism coding genes likely favor bacterial adaptation to host selective pressures. Therefore, the bacterial pathoadaptive evolution in these severe COPD patients raise our awareness of the possible spread of macrolide resistance and selection of host-adapted clones.
MICROBIOLOGY SPECTRUM
(2023)
Article
Immunology
Sharon L. Clark, Elke J. Seppanen, Lea-Ann S. Kirkham, Laura A. Novotny, Lauren O. Bakaletz, Allan W. Cripps, Karli Corscadden, Harvey Coates, Shyan Vijayasekaran, Peter C. Richmond, Ruth B. Thornton
Summary: The study found that Australian Aboriginal children with chronic and recurrent otitis media had lower serum IgG titers to non-typeable Haemophilus influenzae (NTHi) protein vaccine candidate antigens, suggesting a reduced ability to develop persistent IgG responses due to repeated exposure to various bacterial strains.
FRONTIERS IN CELLULAR AND INFECTION MICROBIOLOGY
(2022)
Article
Microbiology
Benjamin Tuck, Elizabeth Watkin, Anthony Somers, Maria Forsyth, Laura L. Machuca
Summary: Biofilm formation is a global concern, and this research reveals that reducing the concentration of environmentally sustainable biocides and incorporating an eDNA degradation stage can significantly reduce the viability of mature biofilms, leading to biofilm dispersal and antimicrobial enhancement.
Article
Microbiology
Sudeshna Saha, Alison Coady, Aniruddha Sasmal, Kunio Kawanishi, Biswa Choudhury, Hai Yu, Ricardo U. Sorensen, Jaime Inostroza, Ian C. Schoenhofen, Xi Chen, Anja Munster-Kuhnel, Chihiro Sato, Ken Kitajima, Sanjay Ram, Victor Nizet, Ajit Varki
Summary: This study demonstrates the presence of anti-Kdn antibodies in humans, suggesting a potential role for Kdn in combating pathogens that rely on nonhuman sialic acids for colonization and virulence. The interaction between Kdn and the immune system provides insights for potential therapeutic interventions against pathogenic bacteria that cloak themselves in external sialic acids.