Baobab Index

We present the first assessment of the diet of the blackchin guitarfish Glaucostegus cemiculus (Geoffroy Saint-Hilaire, 1817) for West Africa using DNA metabarcoding on stomach contents of individuals captured in the Bijagós Archipelago, Guinea-Bissau. The diet was dominated by crustaceans, particularly caramote prawn Penaeus kerathurus (frequency of occurrence [FO] = 74%, numerical frequency [NF] = 54%) and fiddler crab Afruca tangeri (FO = 74%, NF = 12%). Bony fishes were present in 30% of the stomachs. We highlight the importance of conservation action for intertidal habitats and their associated benthic invertebrates for the survival of the critically endangered blackchin guitarfish.

Insecticide resistance is reducing the efficacy of vector control interventions, consequently threatening efforts to control vector-borne diseases, including malaria. Investigating the prevalence of molecular markers of resistance is a useful tool for monitoring the spread of insecticide resistance in disease vectors. The Bijagós Archipelago (Bijagós) in Guinea-Bissau is a region of stable malaria transmission where insecticide-treated nets are the mainstay for malaria control. However, the prevalence of molecular markers of insecticide resistance in malaria vectors is not well understood. A total of 214 Anopheles mosquitoes were analysed from 13 islands across the Bijagós. These mosquitoes were collected using CDC light traps in November 2019, during the peak malaria transmission season. High-throughput multiplex amplicon sequencing was used to investigate the prevalence of 17 different molecular markers associated with insecticide resistance in four genes: vgsc, rdl, ace1 and gste2. Of the 17 screened mutations, four were identified in mosquitoes from the Bijagós: vgsc L995F (12.2%), N1570Y (6.2%) and A1746S (0.7%) and rdl A269G (1.1%). This study is the first to report the L995F knock-down resistance (kdr)-west allele in Anopheles melas on the Archipelago. An additional eight non-synonymous single-nucleotide polymorphisms were identified across the four genes which have not been described previously. The prevalences of the vgsc L995F and N1570Y mutations were higher on Bubaque Island than on the other islands in this study; Bubaque is the most populous island in the archipelago, with the greatest population mobility and connection to continental Guinea-Bissau. This study provides the first surveillance data for genetic markers present in malaria vectors from islands across the Bijagós Archipelago. Overall prevalence of insecticide resistance mutations was found to be low. However, the identification of the vgsc L995F and N1570Y mutations associated with pyrethroid resistance warrants further monitoring. This is particularly important as the mainstay of malaria control on the islands is the use of pyrethroid insecticide-treated nets.

Skin scar formation following Bacille Calmette-Guérin (BCG) or smallpox (Vaccinia) vaccination is an established marker of successful vaccination and 'vaccine take'. Potent pathogen-specific (tuberculosis; smallpox) and pathogen-agnostic (protection from diseases unrelated to the intentionally targeted pathogen) effects of BCG and smallpox vaccines hold significant translational potential. Yet despite their use for centuries, how scar formation occurs and how local skin-based events relate to systemic effects that allow these two vaccines to deliver powerful health promoting effects has not yet been determined. We review here what is known about the events occurring in the skin and place this knowledge in the context of the overall impact of these two vaccines on human health with a particular focus on maternal-child health.

Anopheles melas is an understudied malaria vector with a potential role in malaria transmission on the Bijagós Archipelago of Guinea-Bissau. This study presents the first whole-genome sequencing and population genetic analysis for this species from the Bijagós. To our knowledge, this also represents the largest population genetic analysis using WGS data from non-pooled An. melas mosquitoes. WGS was conducted for 30 individual An. melas collected during the peak malaria transmission season in 2019 from six different islands on the Bijagós Archipelago. Bioinformatics tools were used to investigate the population structure and prevalence of insecticide resistance markers in this mosquito population. Insecticide resistance mutations associated with pyrethroid resistance in Anopheles gambiae s.s. from the Bijagós were absent in the An. melas population, and no signatures of selective sweeps were identified in insecticide resistance-associated genes. Analysis of structural variants identified a large duplication encompassing the cytochrome-P450 gene cyp9k1. Phylogenetic analysis using publicly available mitochondrial genomes indicated that An. melas from the Bijagós split into two phylogenetic groups because of differentiation on the mitochondrial genome attributed to the cytochrome C oxidase subunits COX I and COX II and the NADH dehydrogenase subunits 1, 4, 4L and 5. This study identified an absence of insecticide-resistant SNPs common to An. gambiae in the An. melas population, but did identify structural variation over insecticide resistance-associated genes. Furthermore, this study presents novel insights into the population structure of this malaria vector using WGS analysis. Additional studies are required to further understand the role of this vector in malaria transmission.

Vector control in the Bijagós Archipelago of Guinea-Bissau currently relies on pyrethroid insecticide-treated nets. However, data on insecticide resistance in Guinea-Bissau is limited. This study identified deltamethrin resistance in the Anopheles gambiae sensu lato complex on Bubaque island using WHO tube tests in November 2022. Whole genome sequencing of An. gambiae sensu stricto mosquitoes identified six single nucleotide polymorphisms (SNPs) previously associated with, or putatively associated with, insecticide resistance: T791M, L995F, N1570Y, A1746S and P1874L in the vgsc gene, and L119V in the gste2 gene. Twenty additional non-synonymous SNPs were identified in insecticide-resistance associated genes. Four of these SNPs were present at frequencies over 5% in the population: T154S, I126F and G26S in the vgsc gene and A65S in ace1. Genome wide selection scans using Garud's H

The beneficial effects of Bacillus Calmette-Guérin (BCG) as an intervention against non-mycobacterial infections have been extensively studied in randomized trials. These non-specific effects have been linked to a heterologous increase of pro-inflammatory cytokine production by innate immune cells. It is unknown if BCG induces such responses in older individuals from TB-endemic countries. In a single-blinded trial in Guinea-Bissau, 40 adults over 50 years of age were randomized 1:1 in a block of 40 to intradermal injection of BCG-Japan (intervention) or solvent (placebo). Production of interleukin (IL)-1β, IL-6, IL-10, interferon (IFN)-γ and tumor necrosis factor (TNF)-α was measured by ELISA in supernatant of peripheral blood mononuclear cells stimulated with Mycobacterium tuberculosis and heterologous pathogens. The trial was registered at clinicaltrials.gov (NCT02953327). Between January 25 and March 7, 2017, 40 individuals were randomized. Two months after vaccination, BCG-Japan recipients (n = 11) had higher production of IFN-γ to M. tuberculosis stimulation (Geometric mean ratio (GMR): 3·91 [95 % Confidence Interval (CI), 1·53-9·96]) and increased release of the pro-inflammatory innate cytokines IL-1β, IL-6 and TNF-α to non-specific stimuli (GMR TNF-α: 1·47 [95 % CI, 0·98-2·19]) than their controls (n = 13). Both the specific and non-specific responses were more pronounced among those with a positive QuantiFERON at baseline. BCG-Japan can induce a trained immunity phenotype in older adults. These effects were particularly strong in previously M. tuberculosis exposed individuals. Future randomized trials are needed to determine BCG's potential to protect the older populations from infections-driven morbidity and mortality.

This study aimed to explore and document putative exotic marine benthic invertebrate species in the Bijagós Archipelago, Guinea-Bissau, to enhance understanding of marine biodiversity and address the extent of marine species introductions. The research was conducted in the Bijagós Archipelago, a UNESCO Biosphere Reserve located in Guinea-Bissau. The study involved the region's first scuba-diving survey of marine biodiversity. DNA barcoding was employed to assist in the identification of benthic invertebrate species. Molecular phylogenetic analyses were conducted with the available DNA barcodes to ensure accurate taxonomic assignments, detect cryptic species, and investigate the phylogeography of the taxa. The survey resulted in the discovery of 28 new species records for the Bijagós Archipelago, including octocorals, scleractinians, hydroids, bryozoans, barnacles, and ascidians. Among these, six species were documented for the first time in the East Atlantic:

Understanding how small populations cope with loss of genetic diversity and deleterious variation is crucial to address the current biodiversity crisis. Insular populations are particularly interesting as they have often persisted at lower population sizes and higher inbreeding than their mainland counterparts. While the genome-wide consequences of inbreeding in threatened insular species have received some attention, comparative genomics between insular and mainland populations of widespread and genetically diverse species have rarely been performed. Yet, they are particularly well suited to inform about the consequences of drastic population declines from initially large populations-a phenomenon that is becoming increasingly common. The spot-nosed monkey (Cercopithecus petaurista), the Campbell's monkey (Cercopithecus campbelli) and the green monkey (Chlorocebus sabaeus) are common and genetically diverse West African primates. Insular populations can be found at the Bijagós Archipelago, Guinea-Bissau. Here, we assessed the genome-wide diversity, inbreeding, genetic load and adaptive variation using whole genome sequencing data from insular and mainland populations. In the three species, island populations showed lower genome-wide diversity and higher inbreeding. Genetic drift has likely promoted the conversion of masked genetic load into realised load without increased purging of deleterious variation. Additionally, we found no evidence for accumulation of deleterious variation, suggesting that these populations are not yet at risk of extinction by genetic factors and may act as reservoirs of extant mainland genetic diversity. We highlight, however, that other anthropogenic factors are threatening these insular primates, and therefore conservation management should target their immediate threats and safeguard against additional loss of diversity.

The western chimpanzee (

Marine turtles undertake long migrations across different geographies and habitats, exposing them to a wide range of threats throughout their lifespan. Analysing population structure and connectivity is key to informing effective conservation management. We expand knowledge of Atlantic-wide connectivity of green turtles ( The online version contains supplementary material available at 10.1007/s10592-025-01720-3.