Antimicrobial susceptibility, serotype and genotype distribution of meningococci in Portugal, 2001-2002

Neisseria meningitidis with decreased susceptibility to penicillin G and molecular characterization of the penA gene in strains isolated at University Hospital Centers of Casablanca and Marrakech (Morocco)

Introduction

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.

Methods

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.

Results

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).

Conclusion

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.

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).

Characterization of Neisseria meningitidis isolates from Egypt using multilocus sequence typing

To characterize Neisseria meningitidis isolates collected from cerebrospinal fluid of meningitis cases in Egypt (1998-2003) as part of surveillance studies, 67 isolates were serogrouped, tested for antibiotic sensitivity and analyzed using multilocus sequence typing (MLST). Results show that isolates expressing serogroup B (50.7%) and serogroup A (34.3%) antigens were predominant in Egypt during the surveillance period, possibly due to suppression of other serogroups by meningococcal vaccines in current use. Intermediate resistance to penicillin was observed in 71% of the isolates, suggesting a need for physicians to shift to third-generation cephalosporins during the empirical treatment of infection. Recurrent lineages of N. meningitidis in Egypt appear to originate from Europe and other Middle Eastern countries. Of 19 sequence types detected, five were unique to Africa and 10 were not observed previously in the MLST database. The information obtained illustrates the changing dynamics of meningitis after vaccine introduction in Egypt.