Since 1941, outbreaks of Neisseria meningitidis have been recorded in Chile which, to date, have varied according to clinical form, incidence, lethality, and the responsible serogroup.
OBJECTIVE: To summarize the available evidence on the epidemiological profile of acute bacterial meningitis due to Neisseria meningitidis in Chile, analyzing the incidence between 1990 and 2019.
METHODS: A systematized review of primary articles was carried out following the Cochrane Collaboration standards. The information sources were PubMed, Scielo, and LILACS. Publications on acute bacterial meningitis due to Neisseria meningitidis were included, with a descriptive design, and in English and Spanish. Studies on the effectiveness of vaccines and diagnostic techniques were excluded.
RESULTS: Between 1990 and 2019, the evidence collected focuses exclusively on the year 2012. Of the 133 cases of invasive meningococcal disease (IMD) reported that year, 42 cases presented with meningitis. Of the IMD cases caused by serogroup W135 strains, 21.7% of the cases presented with meningitis (13 cases), compared with the \"Non-W135\" strains, in which it was 67.4% (29 cases). Lethality due to IMD was higher in patients affected by serogroup W135 (26.7%), compared with patients affected by serogroup \"Non-W135\" (13.9%).
CONCLUSIONS: The year 2012 shows a change in the prevalent serogroup from serogroup B to W, with a decrease in cases of meningitis and an increase in cases of meningo- coccemia and the lethality of IMD.

BACKGROUND Meningococcal meningitis is rare in Japan; however, when outbreaks do occur, they predominantly involve domestically infected cases rather than those contracted overseas. CASE REPORT A Japanese man with diabetes in his 50s experienced fever and loss of consciousness, with no history of international travel. In our hospital, gram-negative diplococci were detected in the cerebrospinal fluid (CSF) of the patient by Gram staining, although the rapid agglutination test and cultures of blood and CSF were negative. Multiplex polymerase-chain reaction (PCR) testing returned positive results for meningococcus and parechovirus. Brain MRI revealed a finding of meningitis, but there were no indications of encephalitis. To determine the serotype and genotype, we sent the sample to the National Institute of Infectious Diseases, which identified the serogroup and sequence type (ST) as type B and 2057, respectively. Despite the unknown antimicrobial susceptibility, the patient responded well to empirical treatment with ceftriaxone at 2 g every 12 h, and was discharged with remaining symptoms of dizziness, headache, difficulty hearing in the left ear, and tinnitus in the left ear. CONCLUSIONS In Japan, vaccines covering serogroups A, C, and W/Y are available but not routinely administered. According to epidemiological surveillance reports, serogroup B is the second most common cause of meningococcal meningitis in Japan, yet there is no corresponding vaccine available in the country. This case has prompted a review of the epidemiology of meningococcus in Japan, encompassing strategies for vaccination and hospital infection control to prevent droplet transmission, which includes post-exposure prophylaxis when no prior measures have been implemented.

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The genus Neisseria, which colonizes mucosal surfaces, includes both commensal and pathogenic species that are exclusive to humans. The two pathogenic Neisseria species are closely related but cause quite different diseases, meningococcal sepsis and meningitis (Neisseria meningitidis) and sexually transmitted gonorrhea (Neisseria gonorrhoeae). Although obvious differences in bacterial niches and mechanisms for transmission exists, pathogenic Neisseria have high levels of conservation at the levels of nucleotide sequences, gene content and synteny. Species of Neisseria express broad-spectrum O-linked protein glycosylation where the glycoproteins are largely transmembrane proteins or lipoproteins localized on the cell surface or in the periplasm. There are diverse functions among the identified glycoproteins, for example type IV biogenesis proteins, proteins involved in antimicrobial resistance, as well as surface proteins that have been suggested as vaccine candidates. The most abundant glycoprotein, PilE, is the major subunit of pili which are an important colonization factor. The glycans attached can vary extensively due to phase variation of protein glycosylation (pgl) genes and polymorphic pgl gene content. The exact roles of glycosylation in Neisseria remains to be determined, but increasing evidence suggests that glycan variability can be a strategy to evade the human immune system. In addition, pathogenic and commensal Neisseria appear to have significant glycosylation differences. Here, the current knowledge and implications of protein glycosylation genes, glycan diversity, glycoproteins and immunogenicity in pathogenic Neisseria are summarized and discussed.

Inspired by the specificity of α-(2,9)-sialyl epitopes in bacterial capsular polysaccharides (CPS), a doubly fluorinated disaccharide has been validated as a vaccine lead against Neisseria meningitidis serogroups C and/or B. Emulating the importance of fluorine in drug discovery, this molecular editing approach serves a multitude of purposes, which range from controlling α-selective chemical sialylation to mitigating competing elimination. Conjugation of the disialoside with two carrier proteins (CRM197 and PorA) enabled a semisynthetic vaccine to be generated; this was then investigated in six groups of six mice. The individual levels of antibodies formed were compared and classified as highly glycan-specific and protective. All glycoconjugates induced a stable and long-term IgG response and binding to the native CPS epitope was achieved. The generated antibodies were protective against MenC and/or MenB; this was validated in vitro by SBA and OPKA assays. By merging the fluorinated glycan epitope of MenC with an outer cell membrane protein of MenB, a bivalent vaccine against both serogroups was created. It is envisaged that validation of this synthetic, fluorinated disialoside bioisostere as a potent antigen will open new therapeutic avenues.

A 13-year-old boy was admitted with severe meningococcal meningitis. Immunologic workup revealed a properdin deficiency, and genetic sequencing of CFP identified a novel, private and predicted pathogenic variant in exon 8. The patient received broad immunizations and penicillin prophylaxis. Children with invasive meningococcal disease should be tested for complement deficiency.

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UNASSIGNED: the laboratory diagnosis of meningococcal meningitis relies on conventional techniques. This study aims to evaluate the correlation between the reduced sensitivity to penicillin G of Neisseria meningitidis (N.m) strains and the expression of the altered PBP 2 gene.
UNASSIGNED: out of 190 strains of N.m isolated between 2010 and 2021 at the bacteriology laboratories of Ibn Rochd University Hospital Centre (IR-UHC) in Casablanca and the UHC Mohammed VI in Marrakech, 23 isolates were part of our study. We first determined their state of sensitivity to penicillin G by E-Test strips and searched for the expression of the penA gene by PCR followed by Sanger sequencing.
UNASSIGNED: of all the confirmed cases of N.m, 93.15% (n=177) are of serogroup B, 75.2% (n = 143) are sensitive to penicillin G and 24.73% (n = 47) are of intermediate sensitivity. No resistance to penicillin G was observed. Reduced sensitivity to penicillin G in N.m is characterized by mutations namely F504 L, A510 V, I515 V, G541 N and I566 V located in the C-terminal region of the penA gene encoding the penicillin-binding protein 2 (PBP2) (mosaic gene).
UNASSIGNED: our study presents useful data for the phenotypic and genotypic monitoring of resistance to penicillin G in N.m and can contribute to the analysis of genetic exchanges between different Neisseria species.

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.
CONCLUSIONS: This developed and optimized method can complement for the available gold standard for the timely diagnosis of meningococcal meningitis and meningococcemia.