Pneumococcal Meningitis Outbreak Tracked to PCR Confirmed Genotypes of Streptococcus Pneumoniae in Parts of Northern Nigeria
Pneumococcal meningitis caused by Streptococcus pneumoniae strains has been reported as the third major aetiology of bacterial meningitis in parts of Northern Nigeria. However, information on the genotypes of S. pneumoniae strains circulating in Northern Nigeria are unavailable in literature. Genotyping is being practiced widely in medical microbiology and has been proved an invaluable tool in tracking strains responsible for disease outbreaks. We aimed at determining the genotypes of S. pneumoniae linked to pneumococcal meningitis outbreak in parts of Northern Nigeria. The multilocus sequence typing scheme developed for S. pneumoniae, a DNA sequencing-based genotyping method of sequencing of segments of seven internal housekeeping genes was used. The PubMLST.org database and Bacterial Isolate Genome Sequence Database software were equally used. Of the eight genotyped isolates, three (37.5 %) had detectable genotypes: genotype aroE in two cases (25 %), found circulating within serotype 4 (Wzy 4); and genotype gki, one case (12.5 %) found circulating within serotype 5 (Wzy 5). The MLST results provided an overview of circulating S. pneumoniae genotypes and their genetic status; an important information for public health strategies such as vaccination. To develop more effective vaccines, it is imperative that the candidate vaccines are evaluated against a set of carefully selected genotypes, which are representative of the pathogen isolated.However, information on the circulating invasive genotypes of Haemophilus influenzae in Northern Nigeria are unavailable in literature. We aimed at determining the invasive genotypes of H. influenzae strains implicated with cerebrospinal meningitis outbreak in parts of Northern Nigeria. The multilocus sequence typing scheme developed for H. influenzae which is a DNA sequencing-based genotyping method of sequencing of segments of seven internal housekeeping genes was used. The PubMLST.org database and Bacterial Isolate Genome Sequence Database software were equally used. Of the 12 genotyped isolates, six (50 %) had detectable genotypes: genotype adk in two cases (16.7 %) found circulating amongst serotypes e (ecsH) and f (bexD); genotype fucK, two cases (16.7 %) amongst serotypes b (bcsB) and f (bexD); and genotype mdh in two cases (16.7 %) amongst serotypes b (bcsB) and e (ecsH). The three genotypes are now documented as invasive strains. Therefore, for a preventive vaccination programme against cerebrospinal meningitis caused by H. influenzae to be successful in Nigeria, these identified genotype strains should be included in the composition of the vaccines for administration.
