Investment in SARS-CoV-2 sequencing in Africa over the past year has led to a major increase in the number of sequences generated, now exceeding 100,000 genomes, used to track the pandemic on the continent. Our results show an increase in the number of African countries able to sequence domestically, and highlight that local sequencing enables faster turnaround time and more regular routine surveillance. Despite limitations of low testing proportions, findings from this genomic surveillance study underscore the heterogeneous nature of the pandemic and shed light on the distinct dispersal dynamics of Variants of Concern, particularly Alpha, Beta, Delta, and Omicron, on the continent. Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve, while the continent faces many emerging and re-emerging infectious disease threats. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century.

Background. Diarrhoea due to gastrointestinal infections is a significant problem facing the South African (SA) healthcare system. Infections can be acquired both from the community and from the hospital environment itself, the latter acting as a reservoir for potential pathogenic bacteria. Objectives. To examine the prevalence of a panel of potential diarrhoeacausing bacteria in patients attending a tertiary healthcare facility in Cape Town, SA. Methods. Polymerase chain reaction (PCR) primers specific for Clostridium difficile, Shigella spp., Salmonella spp., Klebsiella oxytoca, enteropathogenic and enterohaemorrhagic Escherichia coli (EPEC/EHEC), Staphylococcus aureus, enterotoxigenic Bacteroides fragilis and Campylobacter spp. were used to screen total bacterial genomic DNA extracted from stool samples provided by 156 patients with diarrhoea attending Groote Schuur Hospital, Cape Town, SA. Results. C. difficile was the most frequently detected pathogen (16% of cases) in the 21 87yearold patient range, but was not present in samples from the 16 20yearold range. K. oxytoca (6%), EPEC/EHEC strains (9%) and S. aureus (6%) were also detected. The remaining pathogens were present at low frequencies (0 2.9%), and the occurrence of mixed infections was 5%. The majority of nonC. difficilerelated diarrhoeas were community acquired. Conclusion. C. difficile was the main cause of infectious diarrhoea in the sampled patients, while K. oxytoca and EPEC/EHEC strains were present as relatively minor but potentially significant pathogens.

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Bacteroides fragilis is an opportunistic pathogen which can cause life threatening infections in humans and animals. The ability to adhere to components of the extracellular matrix, including collagen, is related to bacterial host colonisation. Collagen Far Western analysis of the B. fragilis outer membrane protein (OMP) fraction revealed the presence two collagen adhesin bands of ∼31 and ∼34 kDa. The collagen adhesins in the OMP fraction were separated and isolated by two-dimensional SDS-PAGE and also purified by collagen affinity chromatography. The collagen binding proteins isolated by both these independent methods were subjected to tandem mass spectroscopy for peptide identification and matched to a single hypothetical protein encoded by B. fragilis NCTC 9343 (BF0586), conserved in YCH46 (BF0662) and 638R (BF0633) and which is designated in this study as cbp1 (collagen binding protein). Functionality of the protein was confirmed by targeted insertional mutagenesis of the cbp1 gene in B. fragilis GSH18 which resulted in the specific loss of both the ∼31 kDa and the ∼34 kDa adhesin bands. Purified his-tagged Cbp1, expressed in a B. fragilis wild-type and a glycosylation deficient mutant, confirmed that the cbp1 gene encoded the observed collagen adhesin, and showed that the 34 kDa band represents a glycosylated version of the ∼31 kDa protein. Glycosylation did not appear to be required for binding collagen. This study is the first to report the presence of collagen type I adhesin proteins in B. fragilis and to functionally identify a gene encoding a collagen binding protein.

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