Neisseria meningitidis disease-associated clones in Amazonas State, Brazil

Meningococcal Antibiotic Resistance: Molecular Characterization of Isolates from Patients with Invasive Meningococcal Disease (IMD) in Greece

For effective case management and chemoprophylaxis of Invasive Meningococcal Disease (IMD), prompt antibiotic treatment is required. N. meningitidis is usually susceptible to antibiotics, but reduced susceptibility to penicillin, ciprofloxacin, and rifampicin is increasing worldwide, jeopardizing patients' outcome. We assessed, phenotypically and genotypically, the antimicrobial resistance patterns of 192 strains isolated from IMD cases from all over Greece during 2010-2021. Antimicrobial susceptibility to penicillin, rifampicin, and ciprofloxacin was determined using the E-test. All isolates were genotyped by Multilocus Sequence Typing (MLST). penA, rpoB, and gyrA genes were amplified by PCR and sequenced. Of the 192 isolates, 37% (72/192) were penicillin-susceptible/had increased exposure, and 11% (21/192) were penicillin-resistant. Among those, 40 penA alleles were identified; penA1, penA27, and penA3 were highly associated with susceptibility to penicillin; penA14, penA25, and penA22 related to reduced susceptibility to penicillin, while penA9, penA910, and penA295 had resistance to penicillin. Two ciprofloxacin-resistant isolates harbored the gyrA346 allele, while one rifampicin-resistant isolate harbored the rpoB5 allele. Resistance to ciprofloxacin and rifampicin remains rare. As Greece is one of the countries with high antimicrobial resistance, continued monitoring of antibiotic resistance is important to ensure timely detection of emerging resistance for treatment and prevention guidelines.

High-Resolution Melting (HRM) for rapid MLST analysis of Neisseria meningitidis

The genetic characterization of meningococcal isolates is extremely important for the epidemiological monitoring of meningococcal disease, through the identification of circulating epidemic clones, with the purpose of supporting specific actions of Health Surveillance to contain outbreaks. The objective of this work is to determine a strategy for the epidemiological control of Neisseria meningitidis (Nm) through the detection of genetic signatures of Multilocus Sequence Typing (MLST) genes, by the method of high-resolution DNA melting analysis (qPCR-HRM), to identify the main hypervirulent clones circulating in the country. We analyzed 65 cc103 strains, 19 cc11, 38 cc32 and 8 cc41/44 and 17 were not associated to a specific cc. For the abcZ gene a total of 112 strains were tested, 79 for adk and gdh genes, 87 for aroE, 27 for fumC and 70 strains for pdhC gene. The results obtained were compared and validated with nucleotide sequencing. The percentage of correct allele detection for each clonal complex ranged between 77% and 100%. After an active search in PubMLST, it was found that by inserting results from at least 4 alleles in the MLST database, it is possible to determine the clonal complex of 99% to 100% of the deposited samples. The results obtained in this study suggest that it is possible to identify Nm clonal complexes by a combination analysis of melting curves (TM) of four constitutional genes included in the MLST scheme by qPCR-HRM.

Genomic surveillance of Neisseria meningitidis serogroup B invasive strains: Diversity of vaccine antigen types, Brazil, 2016-2018

Background

Neisseria meningitidis serogroup B remains a prominent cause of invasive meningococcal disease (IMD) in Brazil. Because two novel protein-based vaccines against serogroup B are available, the main purpose of this study was to provide data on the diversity and distribution of meningococcal vaccine antigen types circulating in Brazil.

Methodology

Genetic lineages, vaccine antigen types, and allele types of antimicrobial-associated resistance genes based on whole-genome sequencing of a collection of 145 Neisseria meningitidis serogroup B invasive strains recovered in Brazil from 2016 to 2018 were collected.

Results

A total of 11 clonal complexes (ccs) were identified among the 145 isolates, four of which were predominant, namely, cc461, cc35, cc32, and cc213, accounting for 72.0% of isolates. The most prevalent fHbp peptides were 24 (subfamily A/variant 2), 47 (subfamily A/variant 3), 1 (subfamily B/variant 1) and 45 (subfamily A/variant 3), which were predominantly associated with cc35, cc461, cc32, and cc213, respectively. The NadA peptide was detected in only 26.2% of the isolates. The most frequent NadA peptide 1 was found almost exclusively in cc32. We found seven NHBA peptides that accounted for 74.5% of isolates, and the newly described peptide 1390 was the most prevalent peptide exclusively associated with cc461. Mutated penA alleles were detected in 56.5% of the isolates, whereas no rpoB and gyrA mutant alleles were found.

Conclusion

During the study period, changes in the clonal structure of circulating strains were observed, without a predominance of a single hyperinvasive lineage, indicating that an epidemiologic shift has occurred that led to a diversity of vaccine antigen types in recent years in Brazil.

Epidemiological profile of Neisseria meningitidis in Casablanca, Morocco: 2010-2019

Surveillance of invasive meningococcal diseases (IMD) must be carried out regularly and continuously in order to detect the emergence of strains of reduced susceptibility to antibiotics for therapeutic and prophylactic use and the appearance of new invasive clones. Molecular-typing approaches allow reliable traceability and powerful epidemiological analysis. This is an epidemiological study of Neisseria meningitidis causing meningitis in Casablanca, Morocco. The grouping was confirmed by PCR mainly on the isolates from cerebrospinal fluid (CSF). A total of 245 confirmed isolates of N .meningitidis were obtained between 2010 and 2019 of which 93 % are of group B. Overall, 24 % of all the isolates have a reduced susceptibility to penicillin G, but no resistance to penicillin G has been reported. All the isolated strains are susceptible to third-generation cephalosporins (3GCs). Genotyping by multilocus sequence typing (MLST) of a selection of 18 strains showed that the majority of isolates belong to the invasive clonal complex CC 32(9/18) followed by the CC 41/44(3/18).