Atypical, Yet Not Infrequent, Infections with Neisseria Species
Maria Victoria Humbert1, Myron Christodoulides1
1Molecular Microbiology, School of Clinical and Experimental Sciences, University of Southampton, Faculty of Medicine, Southampton General Hospital, Southampton SO16 6YD, UK.
Abstract:
Neisseria species are extremely well-adapted to their mammalian hosts and they display unique phenotypes that account for their ability to thrive within niche-specific conditions. The closely related species N. gonorrhoeae and N. meningitidis are the only two species of the genus recognized as strict human pathogens, causing the sexually transmitted disease gonorrhea and meningitis and sepsis, respectively. Gonococci colonize the mucosal epithelium of the male urethra and female endo/ectocervix, whereas meningococci colonize the mucosal epithelium of the human nasopharynx. The pathophysiological host responses to gonococcal and meningococcal infection are distinct. However, medical evidence dating back to the early 1900s demonstrates that these two species can cross-colonize anatomical niches, with patients often presenting with clinically-indistinguishable infections. The remaining Neisseria species are not commonly associated with disease and are considered as commensals within the normal microbiota of the human and animal nasopharynx. Nonetheless, clinical case reports suggest that they can behave as opportunistic pathogens. In this review, we describe the diversity of the genus Neisseria in the clinical context and raise the attention of microbiologists and clinicians for more cautious approaches in the diagnosis and treatment of the many pathologies these species may cause.
Insights
Neisseria gonorrhoeae and Neisseria meningitidis cause gonorrhea and meningitis, respectively. This review highlights the diversity of Neisseria species and their potential as opportunistic pathogens, urging cautious clinical approaches.
Area of Science:
- Microbiology
- Infectious Diseases
- Bacteriology
Background:
- Neisseria species are adapted to mammalian hosts, with N. gonorrhoeae and N. meningitidis being primary human pathogens.
- N. gonorrhoeae causes gonorrhea (urethra, cervix), while N. meningitidis causes meningitis and sepsis (nasopharynx).
- Despite distinct niches, these species can cross-colonize, leading to similar clinical presentations.
Purpose of the Study:
- To review the diversity of the genus Neisseria in clinical settings.
- To emphasize the potential of non-pathogenic Neisseria species as opportunistic pathogens.
- To advocate for increased vigilance in diagnosing and treating Neisseria-associated diseases.
Main Methods:
- Literature review of clinical case reports and medical evidence.
- Analysis of Neisseria species' adaptation, pathogenicity, and clinical manifestations.
- Synthesis of information on cross-colonization and opportunistic behavior.
Main Results:
- Neisseria species exhibit diverse clinical presentations and host-pathogen interactions.
- Cross-colonization between N. gonorrhoeae and N. meningitidis can occur.
- Commensal Neisseria species may act as opportunistic pathogens.
Conclusions:
- The genus Neisseria encompasses a broader range of clinical relevance than previously recognized.
- Clinicians and microbiologists should consider opportunistic infections by less common Neisseria species.
- Further research and diagnostic awareness are crucial for managing Neisseria-related pathologies.
Related Concept Videos
Acute Pyelonephritis II: Diagnostic Studies and Management
Bacterial Phylum Spirochaetes
Sexually Transmitted Infections
Bacterial Phylum Chlamydiae
Acute Pyelonephritis I: Introduction
Bacterial Phylum Tenericutes


