The thermotolerant representative of the Bacillus cereus group, Bacillus cytotoxicus, reliably harbors the coding gene of cytotoxin K-1 (CytK-1). This protein is a highly cytotoxic variant of CytK toxin, initially recovered from a diarrheal foodborne outbreak that caused the death of three people. In recent years, the cytotoxicity of B. cytotoxicus has become controversial, with some strains displaying a high cytotoxicity while others show no cytotoxicity towards cell lines. In order to better circumscribe the potential pathogenic role of CytK-1, knockout (KO) mutants were constructed in two B. cytotoxicus strains, E8.1 and E28.3. The complementation of the cytK-1 KO mutation was implemented in a mutant strain lacking in the cytK-1 gene. Using the tetrazolium salt (MTT) method, cytotoxicity tests of the cytK-1 KO and complemented mutants, as well as those of their wild-type strains, were carried out on Caco-2 cells. The results showed that cytK-1 KO mutants were significantly less cytotoxic than the parental wild-type strains. However, the complemented mutant was as cytotoxic as the wild-type, suggesting that CytK-1 is the major cytotoxicity factor in B. cytotoxicus.

Mpox is a zoonosis caused by the monkeypox virus. Here, we report Mali’s index Mpox case, which was clinically identified at the Mali–Guinea border by the national telemedicine center and confirmed by PCR. The library prepared with NextGenPCR™ MPXV Sequencing Library Prep and sequenced on Minion MK1C revealed a genome length of 197,122 bp with an average depth of 1284.4×. The strain belonged to Clade IIb G1 lineage and exhibited 85 mutations relative to NC_063383.1. To decipher genomic epidemiology, genomes ≥ 195 kb were retrieved from NCBI and aligned with MAFFT. Time-resolved phylogenetic reconstruction and ancestral trait inference were performed with TreeTime v0.11.4. A median joining network was built with Popart v1.7. Phylogeographic analysis revealed clustering with Clade IIb (G.1 lineage) linked to the May 2025 outbreak in Sierra Leone.

Foodborne diseases pose a major public health threat in Africa, driven by rapid urbanization, expanding informal food markets, and limited cold-chain infra

Despite the global scale of SARS-CoV-2 genomic surveillance, data from West Africa are limited. In Mali 33,197 confirmed cases and 743 deaths (case fatality ratio: 2.23%) were recorded between March 2020 and August 2025. This study aimed to provide the first comprehensive genomic reconstruction of SARS-CoV-2 variant introductions, transmission pathways, and evolutionary trends in Mali from 2020 to 2023. A total of 548 Malian sequences were used for lineages assignment and variant tracking. For the reconstruction of transmission dynamic a high quality subset of 305 Malian sequences (passing 90% coverage) was analysed alongside 142 closely related global genomes (from 20 countries) identified using the UShER. Time-resolved phylogenetic reconstruction, ancestral trait inference, and molecular clock analyses were performed with TreeTime v0.11.4 to infer variant introductions, local transmission, and substitution rates. Genomic and epidemiological data revealed five distinct epidemic waves driven by the temporal succession of global variants, from 19A/20A lineages in early 2020 to dominant XBB sublineages in 2023. Multiple independent viral introductions were traced primarily to Europe and North America, followed by sustained local and intercontinental transmission, including reciprocal exchanges with neighbouring African countries. The substitution rate was estimated to be 1.56 x 10−3 substitutions per site per year, consistent with global evolutionary trends. Entropy analysis revealed high genetic variability within the spike gene, particularly in the receptor-binding domain. These findings underscore the persistent global connectivity and local evolutionary pressure shaping the trajectory of the pandemic in Mali. These call for the need for sustained genomic surveillance capacity to inform epidemic preparedness and response.

Invasive bacterial infections caused by Streptococcus pneumoniae, Haemophilus influenzae, and Neisseria meningitidis remain a major public health concern. This study aimed to perform the molecular characterization of bacterial strains responsible for meningitis in patients of all ages who met the World Health Organization case definition for meningitis and had cerebrospinal fluid samples collected between January 2021 and December 2022 at the Clinical Bacteriology Laboratory of the National Public Health Institute of Mali. We conducted a surveillance-based observational study using national surveillance data collected between January 2021 and December 2022. Data were collected continuously and in real time throughout the study. The analysis was cross-sectional and descriptive. Data were obtained from samples received at the laboratory, accompanied by individual clinical notification forms. For each sample, demographic data and additional clinical information, including vaccination status, were collected. Infection was diagnosed by isolating invasive strains through culture, confirmed by real-time triplex PCR, and positive cases were further characterized by real-time triplex PCR for serotyping. Overall, 103 infections were confirmed among the 1000 samples received, corresponding to a positivity rate of 10.3%. S. pneumoniae predominated with 62%, followed by H. influenzae type b with 36% and N. meningitidis serogroup X with 2%. The identified serotypes of pneumococcus were predominantly not covered by existing vaccines, particularly serotype 23A (38.30%), while others, including serotypes 1 (17.02%) and 3 (10.63%), are included in the PCV13 vaccine. The distribution of cases by age and gender shows a predominance of males, accounting for 60.2% of cases (62/103). The 0–5 age group is by far the largest, accounting for 76.7% of cases (79/103), with males representing 58. 22% (46 cases). These findings highlight the importance and the need for continuous monitoring surveillance of circulating strains and strengthening vaccination efforts to improve prevention.