An isothermal CRISPR- based lateral flow assay for detection of Neisseria meningitidis.

BACKGROUND: Neisseria meningitidis can cause life-threatening meningococcal meningitis and meningococcemia. Old standard microbiological results from CSF/blood cultures are time consuming. This study aimed to combine the sensitivity of loop-mediated isothermal nucleic acid amplification (LAMP) with the specificity of CRISPR/Cas12a cleavage to demonstrate a reliable diagnostic assay for rapid detection of N. meningitidis. METHODS: A total of n = 139 samples were collected from patients with suspected meningococcal disease and were used for evaluation. The extracted DNA was subjected to qualitative real-time PCR, targeting capsular transporter gene (ctrA) of N. meningitidis. LAMP-specific primer pairs, also targeting the ctrA, were designed and the LAMP products were subjected to CRISPR/Cas12 cleavage reaction. the readout was on a lateral flow strip. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of LAMP-CRISPR/Cas was compared with real-time PCR assays. The limit of detection (LOD) was established with serial dilutions of the target N. meningitidis DNA and calculated by Probit regression analysis. RESULTS: Six LAMP assay-specific primers were developed targeting the ctrA gene of N. meningitidis, which is conserved in all meningococcal serogroups. The LAMP primers did not amplify DNA from other bacterial DNA tested, showing 100% specificity. The use of 0.4 M betaine increased the sensitivity and stability of the reaction. LAMP-CRISPR/Cas detected meningococcal serogroups (B, C, W). The assay showed no cross-reactivity and was specific for N. meningitidis. The LOD was 74 (95% CI: 47-311) N. meningitidis copies. The LAMP-CRISPR/Cas performed well compared to the gold standard. In the 139 samples from suspected patients, the sensitivity and specificity of the test were 91% and 99% respectively. CONCLUSION: This developed and optimized method can complement for the available gold standard for the timely diagnosis of meningococcal meningitis and meningococcemia.

Prevalence, serogroup distribution and risk factors of Neisseria meningitidis carriage in high school and university students in Hungary.

Neisseria meningitidis causes life-threatening invasive meningococcal disease (IMD) with high mortality worldwide. Asymptomatic pharyngeal meningococcus colonisation is an important reservoir for the spread of the bacterium. The aim of this study was to determine N. meningitidis colonisation rates in asymptomatic high school and university students and to identify risk factors for carriage. Oropharyngeal swab samples and data from a self-reported questionnaire were obtained from overall 610 students, among them 303 university students and 307 high school students, aged between 15 and 31 years in Budapest, Hungary, between November 2017 and December 2018. Meningococcal carriage and serogroup of N. meningitidis were determined by RT-PCR from DNA extracted directly from the specimen. N. meningitidis was identified in 212 (34.8 %) of the participants. Significantly higher carriage rate was found among high school students (48.9 %) compared to university students (20.5 %). Peak of colonisation rate was among 17-19-year-old students (48.7 %). Most carriage isolates were non-typable (87.3 %). From the 212 meningococcus carriers, 19 were colonised by serogroup B (9 %), 5 by serogroup C (2.4 %), and 1 had serogroup Y (0.5 %). Significantly higher colonisation rate was found among males (42.4 %) than in females (33.1 %). Antibiotic use in the past 2 months has decreased the rate of meningococcal colonisation. Recent respiratory infection, active or passive smoking and attending parties have not influenced meningococcal colonisation rate significantly. In conclusion, we have found high asymptomatic meningococcus carriage rate among high school students and young adults, however, the majority of the colonizing meningococci were non-typable.

Invasive meningococcal disease in South-Eastern European countries: Do we need to revise vaccination strategies?

Invasive meningococcal disease (IMD) is an acute life-threatening infection caused by the gram-negative bacterium, Neisseria meningitidis. Globally, there are approximately half a million cases of IMD each year, with incidence varying across geographical regions. Vaccination has proven to be successful against IMD, as part of controlling outbreaks, and when incorporated into national immunization programs. The South-Eastern Europe Meningococcal Advocacy Group (including representatives from Croatia, the Czech Republic, Greece, Hungary, Poland, Romania, Serbia, Slovenia and Ukraine) was formed in order to discuss the potential challenges of IMD faced in the region. The incidence of IMD across Europe has been relatively low over the past decade; of the countries that came together for the South-Eastern Meningococcal Advocacy Group, the notification rates were lower than the European average for some country. The age distribution of IMD cases was highest in infants and children, and most countries also had a further peak in adolescents and young adults. Across the nine included countries between 2010 and 2020, the largest contributors to IMD were serogroups B and C; however, each individual country had distinct patterns for serogroup distribution. Along with the variations in epidemiology of IMD between the included countries, vaccination policies also differ.

Meningococcal disease in the Middle East: A report from the Global Meningococcal Initiative.

This review details recent findings from the Global Meningococcal Initiative's (GMI) recent meeting on the surveillance and control strategies for invasive meningococcal disease in the Middle East. The nature of case reporting and notification varies across the region, with many countries using bacterial meningitis as an IMD case definition in lieu of meningitis and septicaemia. This may overlook a significant burden associated with IMD leading to underreporting or misreporting of the disease. Based on these current definitions, IMD reported incidence remains low across the region, with historical outbreaks mainly occurring due to the Hajj and Umrah mass gatherings. The use of case confirmation techniques also varies in Middle Eastern countries. While typical microbiological techniques, such as culture and Gram staining, are widely used for characterisation, polymerase chain reaction (PCR) testing is utilised in a small number of countries. PCR testing may be inaccessible for several reasons including sample transportation, cost, or a lack of laboratory expertise. These barriers, not exclusive to PCR use, may impact surveillance systems more broadly. Another concern throughout the region is potentially widespread ciprofloxacin resistance since its use for chemoprophylaxis remains high in many countries.

Evaluating vaccine-elicited antibody activities against Neisseria gonorrhoeae: cross-protective responses elicited by the 4CMenB meningococcal vaccine.

The bacterial pathogen Neisseria gonorrhoeae is an urgent global health problem due to increasing numbers of infections, coupled with rampant antibiotic resistance. Vaccines against gonorrhea are being prioritized to combat drug-resistant N. gonorrhoeae. Meningococcal serogroup B vaccines such as four-component meningococcal B vaccine (4CMenB) are predicted by epidemiology studies to cross-protect individuals from natural infection with N. gonorrhoeae and elicit antibodies that cross-react with N. gonorrhoeae. Evaluation of vaccine candidates for gonorrhea requires a suite of assays for predicting efficacy in vitro and in animal models of infection, including the role of antibodies elicited by immunization. Here, we present the development and optimization of assays to evaluate antibody functionality after immunization of mice: antibody binding to intact N. gonorrhoeae, serum bactericidal activity, and opsonophagocytic killing activity using primary human neutrophils [polymorphonuclear leukocytes (PMNs)]. These assays were developed with purified antibodies against N. gonorrhoeae and used to evaluate serum from mice that were vaccinated with 4CMenB or given alum as a negative control. Results from these assays will help prioritize gonorrhea vaccine candidates for advanced preclinical to early clinical studies and will contribute to identifying correlates and mechanisms of immune protection against N. gonorrhoeae.

Inference of transmission dynamics and retrospective forecast of invasive meningococcal disease.

The pathogenic bacteria Neisseria meningitidis, which causes invasive meningococcal disease (IMD), predominantly colonizes humans asymptomatically; however, invasive disease occurs in a small proportion of the population. Here, we explore the seasonality of IMD and develop and validate a suite of models for simulating and forecasting disease outcomes in the United States. We combine the models into multi-model ensembles (MME) based on the past performance of the individual models, as well as a naive equally weighted aggregation, and compare the retrospective forecast performance over a six-month forecast horizon. Deployment of the complete vaccination regimen, introduced in 2011, coincided with a change in the periodicity of IMD, suggesting altered transmission dynamics. We found that a model forced with the period obtained by local power wavelet decomposition best fit and forecast observations. In addition, the MME performed the best across the entire study period. Finally, our study included US-level data until 2022, allowing study of a possible IMD rebound after relaxation of non-pharmaceutical interventions imposed in response to the COVID-19 pandemic; however, no evidence of a rebound was found. Our findings demonstrate the ability of process-based models to retrospectively forecast IMD and provide a first analysis of the seasonality of IMD before and after the complete vaccination regimen.

Continuing genomic evolution of the Neisseria meningitidis cc11.2 urethritis clade, NmUC: a narrative review.

Neisseria meningitidis (Nm) is a bacterial pathogen responsible for invasive meningococcal disease. Though typically colonizing the nasopharynx, multiple outbreaks of meningococcal urethritis were first reported in 2015-2016; outbreaks originally presumed to be caused by Neisseria gonorrhoeae (Ng). Genomic analysis revealed that the Nm isolates causing these outbreaks were a distinct clade, and had integrated gonococcal DNA at multiple genomic sites, including the gonococcal denitrification apparatus aniA-norB, a partial gonococcal operon of five genes containing ispD, and the acetylglutamate kinase gene argB with the adjacent gonococcal locus NGO0843. The urethritis isolates had also deleted the group C capsule biosynthesis genes cssA/B/C and csc, resulting in loss of capsule. Collectively, these isolates form the N. meningitidis urethritis clade (NmUC). Genomic analysis of recent (2016-2022) NmUC isolates revealed that the genomic features have been maintained in the clade, implying that they are important for NmUC's status as a urogenital pathogen. Furthermore, the analysis revealed the emergence of a sub-clade, designated NmUC-B, phylogenetically separated from the earlier NmUC-A. This sub-clade has integrated additional gonococcal alleles into the genome, including alleles associated with antimicrobial resistance. NmUC continues to adapt to a urethral niche and evolve as a urogenital pathogen.

Detection of Novel US Neisseria meningitidis Urethritis Clade Subtypes in Japan.

Neisseria meningitidis causes invasive meningococcal diseases and has also been identified as a causative agent of sexually transmitted infections, including urethritis. Unencapsulated sequence type 11 meningococci containing the gonococcal aniA-norB locus and belonging to the United States N. meningitidis urethritis clade (US_NmUC) are causative agents of urethral infections in the United States, predominantly among men who have sex with men. We identified 2 subtypes of unencapsulated sequence type 11 meningococci in Japan that were phylogenetically close to US_NmUC, designated as the Japan N. meningitidis urethritis clade (J_NmUC). The subtypes were characterized by PCR, serologic testing, and whole-genome sequencing. Our study suggests that an ancestor of US_NmUC and J_NmUS urethritis-associated meningococci is disseminated worldwide. Global monitoring of urethritis-associated N. meningitidis isolates should be performed to further characterize microbiologic and epidemiologic characteristics of urethritis clade meningococci.

Australian Meningococcal Surveillance Programme Annual Report, 2022.

In Australia, both probable and laboratory-confirmed cases of invasive meningococcal disease (IMD) are reported to the National Notifiable Diseases Surveillance System (NNDSS). Compared to 2021, the number of IMD notifications in 2022 increased by 81% to 127, alongside the easing of COVID-19 containment measures. Laboratory confirmation occurred in 95% of these cases, with 51% (62/121) diagnosed by bacterial culture and 49% (59/121) by nucleic acid amplification testing. The serogroup was determined for 97% of laboratory-confirmed cases (117/121): serogroup B (MenB) accounted for 83% of infections (100/121); MenW for 4% (5/121); MenY for 10% (12/121); no infections were attributed to MenC disease. Fine typing was available on 67% of the cases for which the serogroup was determined (78/117). In MenB isolates, 27 porA types were detected, the most prevalent of which were P1.7-2,4 (18%;11/62), P1.22,14 (15%; 9/62), P1.18-1,34 (10%; 6/62) and P1.7,16-26 (10%; 6/62). All five MenW infections identified as porA type P1.5,2 with different MLST sequence types (ST): 11, 574, 1287, 12351, 13135 all belonging to clonal complex 11, the hypervirulent strain reported in outbreaks in Australia and overseas. In MenY, the predominant porA type was P1.5-1,10-1 (73%; 8/11), ST 1655 and from clonal complex 23. Children less than 5 years of age and people aged 15-19 years were overrepresented with IMD notifications, accounting for 22% (27/121) and 23% (28/121) of laboratory-confirmed cases respectively. Fifteen percent of laboratory-confirmed notifications (18/121) were in persons aged 45-64 years. MenB infections were detected in all age groups but predominated in persons aged 15-19 years (93% of IMD in this age group; 26/28) and comprised 89% (24/27) of infections in children aged less than 5 years. MenW infections were markedly reduced in 2022, accounting for two IMD detections in children 1-4 years (2/16) and sporadic detections in other older age groups. MenY infections were largely detected in adults aged 45-64 years, accounting for 28% of IMD in this age group (5/18). All 62 cultured IMD isolates had antimicrobial susceptibility testing performed. Minimum inhibitory concentration (MIC) values were categorised using Clinical Laboratory Standards Institute (CLSI) interpretative criteria: 5% (3/62) were defined as penicillin resistant (MIC value ≥ 0.5 mg/L); 71% (44/62) had intermediate susceptibility to penicillin (MIC values 0.125 and 0.25 mg/L) and 24% (15/62) were susceptible to penicillin. All isolates were susceptible to ceftriaxone, ciprofloxacin and rifampicin.

Genomic characterization of invasive meningococcal X isolates from Brazil, 1992–2022 / Caracterización genómica de aislamientos invasivos de meningococo X de Brasil, 1992–2022

Introduction: Invasive meningococcal disease (IMD) is a major health problem. Given the post-COVID-19 pandemic scenario with the loosening of the non-pharmacological measures to control the virus transmission and considering the observed global reduction of meningococcal vaccination coverage, an increase in IMD cases can be expected. Methodology: Using whole-genome sequencing, we characterized six Neisseria meningitidis serogroup X (MenX) isolates recovered from IMD cases in Brazil in the last 30 years. Results: The predominance (66.6%, 4/6) of ST2888 presenting fHbp 160, NHBA 129, NadA 21, and PorA 19,15 was found on isolates. Two novel STs, 15458 and 15477, were described. Conclusion: This study describes the circulation of MenX lineage ST2888 in Brazil, previously reported only in Europe. Continuous universal surveillance is crucial to implement prompt public health measures aiming to prevent and control non-vaccine preventable serogroup X IMD cases.(AU)

Understanding barriers to vaccination against invasive meningococcal disease: a survey of the knowledge gap and potential solutions.

INTRODUCTION: Invasive meningococcal disease (IMD) is a leading cause of life-threatening bacterial meningitis and septicemia. Evidence points to a knowledge gap among parents, teenagers, and healthcare providers (HCPs) regarding IMD and available vaccines, including those against the highly prevalent serogroup B. AREAS COVERED: An online survey was conducted between March 27 and 12 April 2019, to gather insights into the knowledge that parents/guardians have about IMD vaccines. The children were aged 2 months to 10 years in Australia, Brazil, Germany, Greece, Italy, and Spain, 5-20 years in the UK, and 16-23 years in the USA. The findings were discussed in the context of the available literature and solutions were proposed to minimize the knowledge gap and the barriers to vaccination against IMD. EXPERT OPINION: The survey demonstrated that parents have a good understanding of IMD but a limited understanding of the different serogroups and vaccines. The available literature highlighted multiple barriers to IMD vaccine uptake; these may be reduced through education of HCPs, clear recommendations to parents by HCPs, the use of technology, and disease-awareness initiatives that engage parents through physical and digital channels. Further studies are warranted to assess the impact of the COVID-19 pandemic on IMD vaccination.

Evaluating the effect of targeted strategies as control tools for hypervirulent meningococcal C outbreaks: a case study from Tuscany, Italy, 2015 to 2016.

BackgroundMeningococcus (Neisseria meningitidis) is the causative bacteria of invasive meningococcal disease (IMD), a major cause of meningitis and sepsis. In 2015-16, an outbreak caused by serogroup C meningococci (MenC), belonging to the hyperinvasive strain ST-11(cc-11), resulted in 62 IMD cases in the region of Tuscany, Italy.AimWe aimed to estimate the key outbreak parameters and assess the impact of interventions used in the outbreak response.MethodsWe developed a susceptible-carrier-susceptible individual-based model of MenC transmission, accounting for transmission in households, schools, discos/clubs and the general community, which was informed by detailed data on the 2015-16 outbreak (derived from epidemiological investigations) and on the implemented control measures.ResultsThe outbreak reproduction number (Re) was 1.35 (95% prediction interval: 1.13-1.47) and the IMD probability was 4.6 for every 1,000 new MenC carriage episodes (95% confidence interval: 1.8-12.2). The interventions, i.e. chemoprophylaxis and vaccination of close contacts of IMD cases as well as age-targeted vaccination, were effective in reducing Re and ending the outbreak. Case-based interventions (including ring vaccination) alone would have been insufficient to achieve outbreak control. The definition of age groups to prioritise vaccination had a critical impact on the effectiveness and efficiency of control measures.ConclusionsOur findings suggest that there are no effective alternatives to widespread reactive vaccination during outbreaks of highly transmissible MenC strains. Age-targeted campaigns can increase the effectiveness of vaccination campaigns. These results can be instrumental to define effective guidelines for the control of future meningococcal outbreaks caused by hypervirulent strains.

Meningococcal Conjunctivitis in a 54-Year-Old Man: Case Report and Review of the Literature.

Neisseria meningitidis represents an uncommon pathogen of acute bacterial conjunctivitis. In this brief report, we describe a case of meningococcal conjunctivitis in an immunocompetent adult male, with a review of the literature. The patient went to the outpatient ophthalmology clinic complaining of severe ocular discomfort, burning, and redness for more than 2 weeks and, at slit lamp examination, he was diagnosed with a mild conjunctivitis. Microbiology cultures of ocular swabs revealed the growth of colonies, as pure culture, identified as N. meningitidis of serogroup B. A diagnosis of primary meningococcal conjunctivitis was made and treatment of patient with intramuscular injections of ceftriaxone in addition to topical moxifloxacin eye drops for 2 weeks led to clinical improvement and, finally, to a complete recovery, in accordance with microbiological findings. Ophthalmologists must be aware of the possibility of primary meningococcal conjunctivitis cases, even uncommon, and the need to treat with systemic antibiotics and their close contacts with adequate antibiotic chemoprophylaxis.

Invasive meningococcal disease in Norway in the two decades before the COVID-19 pandemic.

OBJECTIVES: Disease caused by the bacterium Neisseria meningitidis remains a worldwide public health challenge, despite the steadily decreasing incidence in Western countries. The objective of this study was to explore the epidemiology of invasive meningococcal disease in Norway over the last two decades. DESIGN: All isolates sent to the National Reference Laboratory from patients with invasive meningococcal disease between the years 2000 and 2019 were analyzed using whole genome sequencing (total: 625). RESULTS: A five-fold decrease in case numbers occurred over this period, and the situation has gone from being dominated by serogroup B to one where serogroups Y and W are more prevalent. Concurrently, the mean age at infection has increased from 18 to 33 years. Among the 350 serogroup B isolates, 87% were an exact match or cross-reactive with one or both the currently available serogroup B vaccines, but the proportion decreased in the past decade. Core genome analyses revealed a high variation in the number of allelic differences accumulated in epidemiologically linked isolates to the point that near-identical isolates were found several years apart. CONCLUSION: Allelic distance is an imprecise metric for the degree of epidemiologic linkage between isolates in N. meningitidis.

Meningococcal factor H-binding protein: implications for disease susceptibility, virulence, and vaccines.

Neisseria meningitidis is a human-adapted pathogen that causes meningitis and sepsis worldwide. N. meningitidis factor H-binding protein (fHbp) provides a mechanism for immune evasion by binding human complement factor H (CFH) to protect it from complement-mediated killing. Here, we discuss features of fHbp which enable it to engage human CFH (hCFH), and the regulation of fHbp expression. Studies of host susceptibility and bacterial genome-wide association studies (GWAS) highlight the importance of the interaction between fHbp and CFH and other complement factors, such as CFHR3, on the development of invasive meningococcal disease (IMD). Understanding the basis of fHbp:CFH interactions has also informed the design of next-generation vaccines as fHbp is a protective antigen. Structure-informed refinement of fHbp vaccines will help to combat the threat posed by the meningococcus, and accelerate the elimination of IMD.

Prevalence and persistence of Neisseria meningitidis carriage in Swedish university students.

The bacterium Neisseria meningitidis causes life-threatening disease worldwide, typically with a clinical presentation of sepsis or meningitis, but can be carried asymptomatically as part of the normal human oropharyngeal microbiota. The aim of this study was to examine N. meningitidis carriage with regard to prevalence, risk factors for carriage, distribution of meningococcal lineages and persistence of meningococcal carriage. Throat samples and data from a self-reported questionnaire were obtained from 2744 university students (median age: 23 years) at a university in Sweden on four occasions during a 12-month period. Meningococcal isolates were characterised using whole-genome sequencing. The carriage rate among the students was 9.1% (319/3488; 95% CI 8.2-10.1). Factors associated with higher carriage rate were age ≤22 years, previous tonsillectomy, cigarette smoking, drinking alcohol and attending parties, pubs and clubs. Female gender and sharing a household with children aged 0-9 years were associated with lower carriage. The most frequent genogroups were capsule null locus (cnl), group B and group Y and the most commonly identified clonal complexes (cc) were cc198 and cc23. Persistent carriage with the same meningococcal strain for 12 months was observed in two students. Follow-up times exceeding 12 months are recommended for future studies investigating long-term carriage of N. meningitidis.

Effectiveness of a Meningococcal Group B Vaccine (4CMenB) in Children.

BACKGROUND: In September 2015, the four-component, protein-based meningococcal serogroup B vaccine (4CMenB; Bexsero) became available for private purchase in Spain. METHODS: We conducted a nationwide matched case-control study to assess the effectiveness of 4CMenB in preventing invasive meningococcal disease in children. The study included all laboratory-confirmed cases of invasive meningococcal disease in children younger than 60 months of age between October 5, 2015, and October 6, 2019, in Spain. Each case patient was matched with four controls according to date of birth and province. 4CMenB vaccination status of the case patients and controls was compared with the use of multivariate conditional logistic regression. RESULTS: We compared 306 case patients (243 [79.4%] with serogroup B disease) with 1224 controls. A total of 35 case patients (11.4%) and 298 controls (24.3%) had received at least one dose of 4CMenB. The effectiveness of complete vaccination with 4CMenB (defined as receipt of at least 2 doses, administered in accordance with the manufacturer's recommendations) was 76% (95% confidence interval [CI], 57 to 87) against invasive meningococcal disease caused by any serogroup, and partial vaccination was 54% (95% CI, 18 to 74) effective. Complete vaccination resulted in an effectiveness of 71% (95% CI, 45 to 85) against meningococcal serogroup B disease. Vaccine effectiveness with at least one dose of 4CMenB was 64% (95% CI, 41 to 78) against serogroup B disease and 82% (95% CI, 21 to 96) against non-serogroup B disease. With the use of the genetic Meningococcal Antigen Typing System, serogroup B strains that were expected to be covered by 4CMenB were detected in 44 case patients, none of whom had been vaccinated. CONCLUSIONS: Complete vaccination with 4CMenB was found to be effective in preventing invasive disease by serogroup B and non-serogroup B meningococci in children younger than 5 years of age.

Meningococcal carriage in men who have sex with men presenting at a sexual health unit in Spain.

Neisseria meningitidis (Nm) is asymptomatically carried in the nasopharynx of 5-10% adults, although certain populations, such as men who have sex with men (MSM), exhibit a higher colonisation rate. Interest in Nm carriage has been renewed, owed to meningitis outbreaks within populations of MSM. The aim of this study was to characterise Nm isolates and risk factors for its carriage among MSM attending a sexual health unit. A retrospective cross-sectional study was undertaken between June 2018 and December 2021. We took anal, oropharyngeal, urethral, and blood samples as part of the sexually transmitted infection screening procedures routinely implemented. Nm isolates were subjected to antimicrobial susceptibility testing; the serogroup and genogroup were determined by multi-locus sequence typing. A total of 399 subjects were recruited, and the Nm oropharyngeal carriage rate was 29%, similar among both people living with HIV (PLWH) and uninfected individuals. Nm carriage was less common in vaccinated individuals, especially those who had received the tetravalent vaccine (2.6% vs. 10.6%, p = 0.008). The most frequent serogroups were B (40%) and non-groupable (45%). Most of the isolates were susceptible to ciprofloxacin (96%) and ceftriaxone (100%). However, we identified 21 strains (20%) belonging to hyperinvasive lineages (CC11, CC4821, CC32, CC41/44, CC213, and CC269), most of which belonged to serogroup B. Given that vaccination with MenACWY was associated with a low Nm carriage, we encourage routine vaccination of all MSM. Moreover, the administration of the meningitis B vaccine should also be assessed considering that several invasive lines included in serogroup B are circulating among MSM.

Genomic characterization of invasive meningococcal X isolates from Brazil, 1992-2022.

INTRODUCTION: Invasive meningococcal disease (IMD) is a major health problem. Given the post-COVID-19 pandemic scenario with the loosening of the non-pharmacological measures to control the virus transmission and considering the observed global reduction of meningococcal vaccination coverage, an increase in IMD cases can be expected. METHODOLOGY: Using whole-genome sequencing, we characterized six Neisseria meningitidis serogroup X (MenX) isolates recovered from IMD cases in Brazil in the last 30 years. RESULTS: The predominance (66.6%, 4/6) of ST2888 presenting fHbp 160, NHBA 129, NadA 21, and PorA 19,15 was found on isolates. Two novel STs, 15458 and 15477, were described. CONCLUSION: This study describes the circulation of MenX lineage ST2888 in Brazil, previously reported only in Europe. Continuous universal surveillance is crucial to implement prompt public health measures aiming to prevent and control non-vaccine preventable serogroup X IMD cases.