This study reports the extraction of phenolic compound from shells and kernels of the Raphia farinifera fruit and the biological activities of the extract. A face-centered composite design was established to optimize the extraction conditions: ethanol/water ratio (0-100%), solvent/powder ratio (10-30 mL/g), and extraction time (90-180 min). Subsequently, the extracts obtained under the optimal conditions were used for the evaluation of the radical scavenging capacity, the capacity to chelate ferric ions, and the antimicrobial and anti-inflammatory activities. The optimal extraction conditions for the shells are an extraction time of 134.24 min, 65% ethanol in water, and a solvent/substrate ratio of 21.16 mL/g, and for the kernel, an extraction time of 180 min, 94.3% ethanol in water, and a solvent/substrate ratio of 18.6 mL/g. In these conditions, the phenolic compounds were 95.36 mg EAG/L for the shell extract and 139.72 mg EAG/L for the kernel extract. The antioxidant activity revealed that the half-maximal inhibitory concentrations (IC₅₀) of the kernel extracts are 22.32 μg/mL and 55.73 g/mL for the shells. A reducing activity of Fe ³⁺ ions with an activity of 308.39 μg EAA/mg for the kernel extracts and 293 μg EAA/mg for the shells was observed. B. cereus was the most sensitive microorganism with a minimum inhibitory concentration (MIC) equal to the minimum bactericidal concentration (MBC) with a value of 156.25 ppm for the kernel extract while the shell extract showed MIC of 625 ppm and MBC of 2500 ppm. The IC₅₀ values for the denaturation of proteins by extracts of shells and kernels are 0.76 μg/mL and 0.56 g/mL, respectively. Membrane stabilization revealed IC₅₀ values of 1054.54 g/mL and 1339 g/mL for the shell and kernel extracts, respectively. This work has shown the potential of Raphia farinifera extracts for the food industry and cosmetics.

The COVID-19 pandemic rapidly evolved in December 2019 and to prevent its spread, effective vaccines were produced and made available to the population. Despite their availability so far in Cameroon, the vaccination coverage remains low. This study aimed at describing the epidemiology of the acceptance of vaccines against COVID-19 in some urban and rural areas of Cameroon. A cross-sectional, descriptive and analytical survey was conducted from March 2021 to August 2021 targeting unvaccinated individuals from urban and rural area. After receiving appropriate administrative authorizations and an ethical clearance from the Institutional Review Board (or Ethics Committee) of Douala University (N° 3070CEI-Udo/05/2022/M), a cluster sampling at many degrees was performed and a language-adapted questionnaire was completed by each consenting participant. Data were analyzed using Epi info version 7.2.2.6 software and for p-values < 0.05, the difference was considered as statistically significant. Out of 1053 individuals, 58.02% (611/1053) participants were residing in urban and 41.98% (442/1053) in rural areas. Good knowledge relative to COVID-19 was significantly higher in urban areas as compared to rural areas (97.55% vs. 85.07, p < 0.000). The proportion of respondents who intended to accept the anti COVID-19 vaccine was significantly higher in urban areas than rural areas (42.55% vs. 33.26, p = 0.0047). Conversely, the proportion of anti COVID-19 reluctant respondents thinking that the vaccine can induce a disease was significantly higher in rural areas than urban areas (54 (35.07 vs. 8.84, p < 0.0001). The significant determinants of anti-COVID-19 acceptance were the level of education (p = 0.0001) and profession in the rural areas (p ≤ 0.0001), and only the profession (p = 0.0046) in the urban areas. This study globally showed that anti-COVID-19 vaccination remains a major challenge in urban as well as rural areas in Cameroon. We should continue sensitizing and educating the population about vaccine importance in preventing the COVID-19 spread.

Kribi is a seaside town that welcomes thousands of tourists each year. However, the poor sanitation condition of its beaches along the Atlantic coast is not without risk for visitors. In this study, we used the formol-ether concentration technique to identify and quantify larvae or eggs of intestinal helminths in waters of three regularly visited Kribi beaches (Mpalla, Ngoyè, and Mboamanga). Results revealed that all identified larvae and eggs were cestodes (Hymenolepis nana) and nematodes (Strongyloides sp., Ascaris sp., Ancylostoma duodenale and Trichuris trichiura). All the helminth eggs and larvae showed high abundance at low tide during rainy seasons. Ancylostoma duodenale eggs, totally absent at Mpalla, were densely present at low tide at Ngoyè (301 ± 15 eggs/L). Trichuris trichiura eggs showed the lowest abundance (0 to 62 eggs/L) at all sites. Abiotic variables indicated that waters at the various beaches were basic (pH: 8.75–9.77), generally warmer (32.44°C at Mpalla in the Short Rainy Season), more oxygenated at low tide, and moderately mineralized at high tide. Positive and significant correlations were observed at Ngoyè at low tide between Strongyloides sp. larvae and dissolved oxygen (P ˂ 0.05); and between Ancylostoma duodenale eggs and temperature (P ˂ 0.05). The overall results indicated that the beaches studied are subjected to fecal pollution. This pollution is more accentuated during low tides than during high tides. Depending on tidal movements, swimmers risk exposure to helminth eggs and larvae known to be responsible for gastroenteritis.

Beaches are major sites of microbiological pollution. Assessment of the abundance of resistant forms of enteric protozoa on these recreational waters is important for the prevention and management of health risks. Based on sedimentation and flotation methods, this study found that Kribi beach waters concentrate considerable amounts of enteric protozoa, which are potentially pathogenic. They include Coccidia (Cryptosporidium sp. and Cyclospora cayetanensis), Amoebae (Endolimax nana, Entamoeba histolytica and Entamoeba coli) and Flagellates (Giardia intestinalis). In general, seasonal changes and tidal cycles have significantly impacted the spread of these parasites along Kribi beaches. Thus, at all sites surveyed (Mpalla, Ngoyè and Mboamanga), maximum protozoan abundances were recorded at low tide and during the rainy seasons. It should also be noted that at each sampling site, significant correlations were recorded between certain protozoa and certain physico-chemical variables (p < 0.05). At Mboamanga, for example, Cryptosporidium sp. and Endolimax nana were positively correlated during the Short Rainy Season with temperature (r = 0.601, p = 0.044 and r = 0.632, p = 0.042). At Mpalla, a positive and significant correlation was observed during the Short Rainy Season between Entamoeba coli and pH (r = 0.605, p = 0.033). The high concentration of resistant forms of these enteric protozoa at Kribi beaches is a real public health threat for bathers. Therefore, in this tourist town, it is urgent to put in place an effective plan for the collection and sustainable treatment of solid and liquid waste, which are the main sources of contamination.

The present study had as objective to assess the microbiological quality and profile of some braised products and their accompanying soups sold in the city of Bangangte (Cameroon) and evaluate the antibiotic susceptibility of selected pathogens isolated in these products. An investigation was conducted in three locations in city of Bangangte in order to assess the environment and working conditions as well as the respect of good hygiene practices. Then, samples of braised fish (05) and its soups (05), and braised chicken (05) and its soups (05) were collected from six vendors in each location. The samples (360) were submitted to microbiological analyses and the isolates were identified at species level using API gallery. The susceptibility of the isolates to 14 antibiotics were tested. The 72 participants involved in this study declared having knowledge on hygiene despite the fact that, most of them had no formal education and do not apply good hygiene practices. Microbiological analyses revealed the poor quality of all the samples of braised products. Fecal coliforms and staphylococci counts higher than the values recommended by norms demonstrated the non-respect of good hygiene and manufacturing practices during the braising activity. The 169 strains isolated from these products belonged to 12 different species: Enterobacter gergoviae, Enterobacter spp., Morganella morganiae, Yersinia enterolitica, Yersinia frederiksenii, Staphylococcus aureus, Staphylococcus epidermitidis, Staphylococcus spp., Clostridium spp., Klebsiella pneumoniae, Enterobacter aerogene, and Proteus mirabilis. Strains which could be considered as marker of braised fish sold in the city of Bangangte were Yersinia enterolitica, Staphylococcus aureus and Klebsiella pneumonia while for braised chicken, they were Yersinia enterolitica, Staphylococcus aureus and Proteus mirabilis. The antibiotic susceptibility test performed on these pathogens revealed that they were resistant with 93.75% having multiple antibiotic resistance index values greater than 0.2. We conclude that the microbiological quality of braised products is poor and we suggest to producers to applicate the good hygiene practices. For breeders, we suggest respecting withdrawal periods and the better use of antibiotics.

The present study aimed to evaluate the antimicrobial activity of aqueous extracts of the mixture of spices used as accompanying soup of braised fish against multidrug resistant (MDR) bacteria isolated from raw and braised fish collected in the city of Bangangté, Cameroon. A survey was conducted in the city of Bangangté to diagnose the braising fish processes. Pathogens were isolated from raw and braised fish samples collected in fish farms and selling points, and their susceptibility to 16 commonly used antibiotics was tested using the Kirby-Bauer disk diffusion method. The aqueous extracts of spices’ formulations used as accompanying soup of braised fish were tested against MDR isolates using the well diffusion method. The results revealed that 13 spices are used in the preparation of accompanying soups of braised fish. Three formulations were identified with mbongo, clove and prekeses as the main differential spices. These formulations were either heated at 100 °C/30 min (process 1) or not (process 2) before being served to consumers’. Fifty-five strains belonging to six species (Salmonella Typhi, Salmonella Paratyphi, Escherichia coli, Escherichia vulneralis, Staphylococcus aureus and Staphylococcus spp.) were isolated from the different samples. Forty-four isolates were resistant to several antibiotics with Multiple Antibiotic Resistance indexes ranging from 0.18 to 0.81. The aqueous extracts of all the formulations were active against the MDR isolates independent of the formulation and preparation process, with inhibition diameters varying significantly (p < 0.05) from one isolate to another. Heated extracts were less active than the unheated ones and the most active extract was from the formulation including clove. The strains E. coli and E. vulneralis were most resistant to the different extracts whereas S. Typhi, S. aureus, Staphylococcus spp. and S. Paratyphi A, were more sensitive. This study evidenced that fish products from Bangangté city contain MDR pathogens and demonstrated that the formulations of spices used as accompanying soup for braised fish are active against these MDR pathogens. It suggests their potential use as strategy to combat the antimicrobial resistance phenomena associated to foodborne gastroenteritis pathogens. It also suggests that more attention should be paid to the use of antibiotics in fish farming activities.