- Volume 5, Issue 3, 2023
Volume 5, Issue 3, 2023
- Research Articles
-
-
-
Increase in prevalence of Streptococcus pneumoniae serogroup 24 in children upon introducing 13-valent pneumococcal conjugate vaccine in Japan
More LessAfter introducing the 13-valent pneumococcal conjugate vaccine (PCV13) for children, a change in the prevalence of different Streptococcus pneumoniae serotypes that cause invasive pneumococcal diseases (IPDs) has been observed. The prevalence of vaccine serotypes has decreased and that of non-vaccine serotypes has increased. Currently, serogroup 24 has become one of the major non-vaccine serotypes causing IPDs in children in Japan. The aim of this study was to characterize clinical and genomic features of S. pneumoniae serogroup 24 strains isolated from sterile body sites in Japanese children. Serotyping, multi-locus sequence typing and genomic analysis of capsular polysaccharides of 61 strains of serogroup 24 were performed from 2015 to 2021. Among the 61 strains, 36, 23 and two belonged to serotypes 24F, 24B and 24C, respectively. The 24F sequence type (ST) 2572 and 24B ST 2572 were the major serotypes and sequence types observed from 2015 to 2019. By contrast, 24F ST 162 and 24B ST 2754 were the two major serotypes and sequence types observed after 2020. Two strains of serotype 24C were detected for the first time in Japan. Sequence analysis of the abpA gene, which plays a role in the synthesis of capsular polysaccharides in S. pneumoniae , was performed to distinguish different strains of serogroup 24. After the introduction of PCV13 in Japan, serogroup 24 has become one of the most prevalent non-vaccine serotypes causing IPDs in children. This serogroup has not been targeted in the next-generation pneumococcal conjugate vaccines. Therefore, monitoring of S. pneumoniae serogroup 24 that causes IPDs in children is essential.
-
-
-
-
Lower respiratory tract microbiome composition and community interactions in smokers
Michael Campos, Trevor Cickovski, Mitch Fernandez, Melita Jaric, Adam Wanner, Gregory Holt, Elio Donna, Eliana Mendes, Eugenia Silva-Herzog, Lisa Schneper, Jonathan Segal, David Moraga Amador, Juan Daniel Riveros, Vanessa Aguiar-Pulido, Santanu Banerjee, Matthias Salathe, Kalai Mathee and Giri NarasimhanThe lung microbiome impacts on lung function, making any smoking-induced changes in the lung microbiome potentially significant. The complex co-occurrence and co-avoidance patterns between the bacterial taxa in the lower respiratory tract (LRT) microbiome were explored for a cohort of active (AS), former (FS) and never (NS) smokers. Bronchoalveolar lavages (BALs) were collected from 55 volunteer subjects (9 NS, 24 FS and 22 AS). The LRT microbiome composition was assessed using 16S rRNA amplicon sequencing. Identification of differentially abundant taxa and co-occurrence patterns, discriminant analysis and biomarker inferences were performed. The data show that smoking results in a loss in the diversity of the LRT microbiome, change in the co-occurrence patterns and a weakening of the tight community structure present in healthy microbiomes. The increased abundance of the genus Ralstonia in the lung microbiomes of both former and active smokers is significant. Partial least square discriminant and DESeq2 analyses suggested a compositional difference between the cohorts in the LRT microbiome. The groups were sufficiently distinct from each other to suggest that cessation of smoking may not be sufficient for the lung microbiota to return to a similar composition to that of NS. The linear discriminant analysis effect size (LEfSe) analyses identified several bacterial taxa as potential biomarkers of smoking status. Network-based clustering analysis highlighted different co-occurring and co-avoiding microbial taxa in the three groups. The analysis found a cluster of bacterial taxa that co-occur in smokers and non-smokers alike. The clusters exhibited tighter and more significant associations in NS compared to FS and AS. Higher degree of rivalry between clusters was observed in the AS. The groups were sufficiently distinct from each other to suggest that cessation of smoking may not be sufficient for the lung microbiota to return to a similar composition to that of NS.
-
- Short Communications
-
-
-
Whole-genome sequencing-based characterization of Streptomyces sp. 6(4): focus on natural product
We have sequenced the whole genome of Streptomyces sp. 6(4) isolated from tomato roots that presents antifungal activity against phytopathogenic fungi, mainly Bipolaris sorokiniana. The genome has almost 7 Mb and 3368 hypothetical proteins that were analysed and characterized in Uniprot with the emphasis on biological compounds. Multilocus sequence typing (MLST) analyses were performed in an effort to characterize and identify this isolate, resulting in a new sequence type (ST), classified as ST64. Phenetic and phylogenetic trees were constructed to investigate Streptomyces sp. 6(4) evolution and sequence similarity, and the isolate is a strain closer to Streptomyces prasinus and Streptomyces viridosporus . It is known that the genus Streptomyces possess huge metabolic capacity with the presence of cryptic genes. These genes are usually present in clusters, which are responsible for the production of diverse natural products, mainly antibiotics. In addition, 6(4) showed 11 biosynthetic gene clusters through antiSMASH, including 3 polyketide synthase (PKS) and non-ribosomal peptide synthase (NRPS) type clusters.
-
-
- Pedagogy
-
-
-
Education-based grant programmes for bottom-up distance learning and project catalysis: antimicrobial resistance in Sub-Saharan Africa
International development and aid are often conducted through the allocation of funding determined by decisions of non-locals, especially in the west for those in the global south. In addition, such funding is often disassociated from local expertise, therefore providing little long-term developmental impact and generating distrust. This is particularly true for conservation, as well as environmental and educational programmes. We hypothesize that by granting local people the educational tools and the necessary funding to develop their own projects through the use of an applicant-driven peer-review approach, it is possible to relocalize the decision-making process to the programme participants, with the potential to generate and select more relevant projects with developmental outcomes of higher quality. Here we created an online curriculum for antimicrobial resistance (AMR) education that was followed by 89 participants across Ghana, Tanzania, Nigeria and Uganda. We then created an open research programme that facilitated the creation of eight de novo projects on AMR. Finally, we organized an applicant-driven grant round to allocate funding to the ‘Neonatal Sepsis in Nigeria’ project to conduct a pilot study and awareness campaign. This work opens perspectives for the design of frugal educational programmes and the funding of context-specific, community-driven projects aimed at empowering local stakeholders in the global South.
-
-