Risk factors, clinical features and outcomes of Neisseria keratitis.

OBJECTIVE: To describe the clinical features, risk factors and outcomes of Neisseria keratitis. METHODS: This is a retrospective observational study wherein medical records of cases with microbiologically proven Neisseria keratitis were reviewed. Data pertaining to the underlying predisposing factors, clinical characteristics of the corneal ulcer, antibiotic susceptibility of the Neisseria species isolate from the corneal scraping, the treatment given, and outcomes were collected and analyzed. RESULTS: Medical records of 60 patients (60 eyes) with Neisseria keratitis were reviewed. Among the causes of poor ocular surface as predisposing factor, vernal keratoconjunctivitis (n = 6 eyes), along with use of topical corticosteroids (n = 18 eyes) was the most common. The ulcer was characterized by a central infiltrate (31/60, 51.7%) involving up to the mid-stroma (43/60, 71.7%). Of the forty-four (73.3%) eyes with pure Neisseria keratitis, 31 eyes (72.1%) resolved with medical therapy alone while five eyes (11.6%) underwent therapeutic penetrating keratoplasty and in two (4.6%) eyes evisceration was performed. The other 5/44 (11.6%) patients were lost to follow-up. Resolution with medical therapy was found to be similar in cases with pure infection and mixed infection (p = 0.58). CONCLUSIONS: Neisseria keratitis most commonly causes a mild form of keratitis and is often associated with the poor ocular surface or prior steroid use. In most cases medical therapy is sufficient for complete resolution of the keratitis.

Two Cases of Newly Characterized Neisseria Species, Brazil.

We describe 2 human cases of infection with a new Neisseria species (putatively N. brasiliensis), 1 of which involved bacteremia. Genomic analyses found that both isolates were distinct strains of the same species, were closely related to N. iguanae, and contained a capsule synthesis operon similar to N. meningitidis.

Neisseria macacae bacteremia: report of two cases with a literature review.

BACKGROUND: Neisseria macacae was discovered in the oral cavity of monkeys in 1983. In humans, it has been isolated from the upper respiratory tract of neutropenic patients. However, only two cases of N. macacae bacteremia have been reported in a 65-year-old man with infective endocarditis and a 5-month-old child with fever and petechiae. There are no reports of infections in cancer patients. Here, we present two cases of N. macacae bacteremia in cancer patients. CASE PRESENTATION: In the first case, a 42-year-old woman who underwent ovarian cancer surgery presented with duodenal invasion associated with multiple lymph node metastasis. N. macacae was isolated from her blood culture and identified using matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry (MS). In the second case, a 69-year-old woman with a long-standing history of esophagogastric junction cancer presented with fever. She had stage IVB cancer with lung, bone, and multiple lymph node metastasis. The last chemotherapy was administered 5 weeks before N. macacae was detected using MALDI-TOF MS and nitrate test negative. In both cases, transthoracic echography showed no vegetation. Antibiotics were administered for 14 and 13 days in the first and second cases, respectively. In both cases, fever alleviated on day 4 of antibiotic administration. Both patients were discharged after their conditions improved. CONCLUSIONS: This, to our knowledge, is the first report of N. macacae bacteremia in cancer patients. Both patients, mucosal damage was observed in the upper gastrointestinal tract. Therefore, exclusion diagnosis suggested that bacteremia invasion was caused by mucosal rupture in both cases. Both cases responded well to treatment with ß-lactam antibiotics and improved after 2 weeks. Modifying the treatment based on the source of the infection may shorten the treatment period. Therefore, further research on N. macacae bacteremia is necessary. Immunocompromised patients such as those with cancer are susceptible to mucosal damage by unusual bacterial species such as N. macacae despite not having contact with monkeys.

Use of Andromas and Bruker MALDI-TOF MS in the identification of Neisseria.

Through the past decade, MALDI-TOF MS has been recognized as a fast and robust tool for identification of most bacteria in clinical microbiology. However, the accuracy of this method to identify Neisseria species is still debated, and few data are available about commensal Neisseria species identification. In this study, we assessed two MALDI-TOF MS systems (Bruker Biotyper and Andromas) for the identification of 88, 18, and 29 isolates of Neisseria gonorrhoeae, Neisseria meningitidis, and commensal Neisseria species, respectively. All 88 isolates of N. gonorrhoeae were correctly identified using both systems, and most N. meningitidis and commensal Neisseria species were well identified: only 1/18 isolates of N. meningitidis was misidentified using Bruker Biotyper, and 1 isolate of Neisseria polysaccharea was misidentified as N. meningitidis using both systems. These results strengthen the possibility to use MALDI-TOF MS as a single method for Neisseria identification in routine, with excellent performance for N. gonorrhoeae identification. However, results should be interpreted prudently for N. meningitdis and commensal Neisseria species when isolated from genital and oropharyngeal samples where these both species can coexist.

To Lick One's Wounds: A Case of Pasteurella canis oralis Osteomyelitis and Neisseria animaloris Infection from Canine Saliva.

The complications of wound infections caused by animal related trauma are well known and explored. Of the numerous polymicrobial etiologies, Neisseria animaloris and Pasteurella canis oralis have been reported only in a limited number of cases. This manuscript explores the rare finding of these species in the case of an 83-year-old male with a diabetic foot wound complicated by infection from the saliva of his pet dog. The case highlights the first instance of P. canis oralis without the setting of a penetrating animal bite, emphasizing the vulnerability of open lesions in patients whose comorbidities impair proper wound healing. These bacteria are susceptible to beta-lactams with beta-lactamase inhibitors and can be treated once identified. It is crucial to recognize rare pathogens and initiate appropriate treatment early, and to emphasize proper wound care, especially in the context of pet interactions.

A Novel Method to Assess Antimicrobial Susceptibility in Commensal Oropharyngeal Neisseria-A Pilot Study.

Commensal Neisseria provide a reservoir of resistance genes that can be transferred to the pathogens Neisseria gonorrhoeae and N. meningitidis in the human oropharynx. Surveillance programs are thus needed to monitor resistance in oropharyngeal commensal Neisseria, but currently the isolation and antimicrobial susceptibility testing of these commensals is laborious, complex and expensive. In addition, the posterior oropharyngeal/tonsillar swab, which is commonly used to sample oropharyngeal Neisseria, is poorly tolerated by many individuals. We evaluated an alternative non-invasive method to isolate oropharyngeal commensal Neisseria and to detect decreased susceptibility to azithromycin using selective media (LBVT.SNR) with and without azithromycin (2 µg/mL). In this pilot study, we compared paired posterior oropharyngeal/tonsillar swabs and oral rinse-and-gargle samples from 10 participants and demonstrated that a similar Neisseria species diversity and number of colonies were isolated from both sample types. Moreover, the proportion of Neisseria colonies that had a decreased susceptibility to azithromycin was similar in the rinse samples compared to the swabs. This pilot study has produced encouraging data that a simple protocol of oral rinse-and-gargle and culture on plates selective for commensal Neisseria with and without a target antimicrobial can be used as a surveillance tool to monitor antimicrobial susceptibility in commensal oropharyngeal Neisseria. Larger studies are required to validate these findings.

Meningococcal disease in North America: Updates from the Global Meningococcal Initiative.

This review summarizes the recent Global Meningococcal Initiative (GMI) regional meeting, which explored meningococcal disease in North America. Invasive meningococcal disease (IMD) cases are documented through both passive and active surveillance networks. IMD appears to be decreasing in many areas, such as the Dominican Republic (2016: 18 cases; 2021: 2 cases) and Panama (2008: 1 case/100,000; 2021: <0.1 cases/100,000); however, there is notable regional and temporal variation. Outbreaks persist in at-risk subpopulations, such as people experiencing homelessness in the US and migrants in Mexico. The recent emergence of ß-lactamase-positive and ciprofloxacin-resistant meningococci in the US is a major concern. While vaccination practices vary across North America, vaccine uptake remains relatively high. Monovalent and multivalent conjugate vaccines (which many countries in North America primarily use) can provide herd protection. However, there is no evidence that group B vaccines reduce meningococcal carriage. The coronavirus pandemic illustrates that following public health crises, enhanced surveillance of disease epidemiology and catch-up vaccine schedules is key. Whole genome sequencing is a key epidemiological tool for identifying IMD strain emergence and the evaluation of vaccine strain coverage. The Global Roadmap on Defeating Meningitis by 2030 remains a focus of the GMI.

Infective endocarditis due to Neisseria elongata: A case report and literature review.

INTRODUCTION: Neisseria elongata (NE), a Gram-negative, rod-shaped organism, was previously thought to be non-pathogenic. However, in recent years it has become increasingly recognized as a rare cause of infective endocarditis. In this paper, we report a case of NE infective endocarditis and provide a review of the literature. OBJECTIVES: To describe a case of NE endocarditis, and to review the literature in search of any similar cases of this rare condition. CASE REPORT: Our patient is a 77-year-old, otherwise healthy female patient who was found to have mitral valve endocarditis with valve regurgitation. DISCUSSION: NE endocarditis is a rare condition that typically affects the left cardiac chambers and is associated with high risk of embolization. A literature review retrieved 35 other cases. CONCLUSIONS: Our report underlines the rarity of NE endocarditis, insofar as relatively few cases have been reported. The bacterium presents similarities with HACEK organisms and can potentially cause infective endocarditis.

The Human Microbiome as a Focus of Antibiotic Discovery: Neisseria mucosa Displays Activity Against Neisseria gonorrhoeae.

Neisseria gonorrhoeae infections are a serious global health problem. This organism has developed disturbing levels of antibiotic resistance, resulting in the need for new approaches to prevent and treat gonorrhea. The genus Neisseria also includes several members of the human microbiome that live in close association with an array of microbial partners in a variety of niches. We designed an undergraduate antibiotic discovery project to examine a panel of nonpathogenic Neisseria species for their ability to produce antimicrobial secondary metabolites. Five strains belonging to the N. mucosa species group displayed activity against other Neisseria in delayed antagonism assays; three of these were active against N. gonorrhoeae. The antimicrobial compound secreted by N. mucosa NRL 9300 remained active in the presence of catalase, trypsin, and HEPES buffer, and effectively inhibited a DNA uptake mutant of N. gonorrhoeae. Antimicrobial activity was also retained in an ethyl acetate extract of plate grown N. mucosa NRL 9300. These data suggest N. mucosa produces an antimicrobial secondary metabolite that is distinct from previously described antigonococcal agents. This work also serves as a demonstration project that could easily be adapted to studying other members of the human microbiome in undergraduate settings. We offer the perspective that both introductory and more advanced course-based and apprentice-style antibiotic discovery projects focused on the microbiome have the potential to enrich undergraduate curricula and we describe transferrable techniques and strategies to facilitate project design.

Atypical, Yet Not Infrequent, Infections with Neisseria Species.

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.

Neisseria models of infection and persistence in the upper respiratory tract.

The Gram-negative bacteria genus Neisseria includes both pathogenic and commensal species that are found primarily in the upper respiratory tract of humans and animals. The development of animal models to study neisserial pathogenesis has focused almost exclusively on two species that cause disease in humans. These include Neisseria meningitidis, an obligate commensal that can cause invasive disease, and N. gonorrhoeae, the causative agent of gonorrhea. Both pathogens can persist in the upper respiratory tract. This article will give a brief overview of the genus Neisseria. The anatomy of the upper respiratory tract and its use as a niche for bacteria will be discussed. Next, studies that provide insight about the first stage of upper respiratory tract infection, namely colonization, will be reviewed. Most studies of upper respiratory tract infection have focused on N. meningitidis infections of laboratory mice. This review will also discuss models of respiratory tract persistence by Neisseria species, including commensals, in mice, non-human primates and human volunteers. The article includes a section that discusses the future utility of upper respiratory tract models in informing the development of effective antimicrobial therapies. Such knowledge is needed to minimize the dissemination of antimicrobial resistance from respiratory reservoirs.