46 results on '"Fokunang C"'
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2. Effect of temperature on the survival and infectivity of Pseudotheraptus devastans vector
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Fokunang, C. N., Dixon, A. G. O., and Ikotun, T.
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- 2004
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3. Evaluation of a cassava germplasm collection for reaction to three major diseases and the effect on yield
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Fokunang, C. N, Akem, C.N., Dixon, A.G.O., and Ikotun, T.
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- 2000
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4. In vitro, greenhouse and field assessments of cassava lines for resistance to anthracnose disease caused by Colletotrichum gloeosporioides f.sp. manihotis
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Fokunang, C. N., Dixon, A. G.O., Ikotun, T., Asiedu, R., Tembe, E. A., and Akem, C. N.
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- 2002
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5. Role of the insect vector, Pseudotheraptus devastans, in cassava anthracnose disease development
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Fokunang, C. N., Akem, C. N., Ikotun, T., Dixon, A. G.O., and Tembe, E. A.
- Published
- 2000
6. DEVELOPMENT OF HEPATOTOXICITY IN INDIVIDUALS HARBOURING DIFFERENT HIV SUBTYPES AND DRUG-RESISTANT VARIANTS IN CAMEROON.
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Abongwa, L. E., Torimiro, J. N., Nyamache, A. K., Fokunang, C., Yengo, C. K., and Okemo, P.
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HEPATOTOXICOLOGY ,LIVER diseases ,TOXIC hepatitis ,DRUG resistance ,HIV infection transmission - Abstract
Objective: The aim of this study was to determine the effect of HIV-1 genetic variants and drug resistance-associated mutations (DRM) on the development of hepatotoxicity. Design and participants: This was a longitudinal study of 81 newly diagnosed HIV-infected individuals in five HIV Treatment clinics in the Northwest Region (NWR) of Cameroon from February 2016 to November 2016. Methodology: Eighty-one antiretroviral drug-naïve patients were recruited into the study and followed-up for 6 months. Blood samples were collected prior to ART initiation and 180 days (D180) later. Serum levels of aminotransferases were analyzed by enzymatic methods. The HIV-1 protease and reverse transcriptase sequences were obtained using an in-house protocol and DRMs were identified using the Stanford HIVDR interpretation program, and HIV-1 subtypes by phylogeny. Results: The mean age of the study participants was 36.5 years. Of these, 37(45.7%) patients showed hepatotoxicity at D180. There were four pure subtypes and five recombinant types with CRF02_AG (74.1%) being the predominant genetic variants. The prevalence of hepatotoxicity was highest among individuals infected with HIV-1 CRF02_AG (70.3%). The prevalence of DRM was 11.1% (9/81). Hepatotoxicity was significantly (p =0.04) higher 77.8% (7/9) among patients with resistant virus. Conclusion: Data from this study reveals a high level of hepatotoxicity among patients with DRM probably as a result of persistent viral replication. These findings highlight the need to conduct routinely DRM surveillance among patients with hepatotoxicity in order to improve patient management and care. [ABSTRACT FROM AUTHOR]
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- 2021
7. Acute toxicity studies, antioxidant and in vitro antibacterial activities of extract from the barks of Ricinodendron heudoletti (Euphorbiaceae)
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Beng V. P, Ngandjui B.T, Mouafo E. T, Fokunang C, Tsafack P, Assam-Assam J. P, Oyono V.A, and Voundi S
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Minimum bactericidal concentration ,Traditional medicine ,biology ,DPPH ,Ricinodendron ,Pathogenic bacteria ,medicine.disease_cause ,biology.organism_classification ,Acute toxicity ,Microbiology ,Minimum inhibitory concentration ,chemistry.chemical_compound ,chemistry ,Drug Discovery ,medicine ,Antibacterial activity ,Bacteria - Abstract
Many bacteria are involved in infectious diseases. Most of these bacteria become resistant to the most commonly used synthetic drugs. In Cameroon, natural substance seem to be an alternative to this problem. Thus the aim of this research was to investigate the acute toxicity, antioxidant activities and the in vitro antibacterial of the methanol extract of Ricinodendron heudelotii (Euphorbiaceae) against twelve pathogenic bacteria involved in infectious diseases. The major bioactive components were also screened. The antibacterial activity of the extract was investigated against 12 strains including 10 Gram- and 2 Gram+ bacteria by disc diffusion method and micro dilution method, followed by another agar disc diffusion for the determination of inhibition diameters, the minimum inhibitory concentration (MICs) and the minimum bactericidal concentration (MBC), respectively. 2,2-Diphenyl-1-Picrylhydrazyl (DPPH) assay was used to evaluate antiradical activity. The acute toxicity study was performed according to World Health Organization (WHO) protocol. The results of the antibacterial assays indicated that the crude extract was active on 8 of 12 strains tested, with MIC ranging from 188 to 750 µg/ml and MBC from 375 to 1500 µg/ml for the extract from barks of R. heudelotii. Overall, the results of this study indicated that the crude extract represented a potential source of antibacterial and antiradical compounds as shown in previous studies and justified their traditional use in the treatment of bacterial infections and other diseases in Cameroon. Key words: Ricinodendron heudelotti, antibacterial activities, bacteria, toxicity.
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- 2014
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8. Insecticidal activity of essential oils of Chenopodium ambrosioides and Cupressus sempervirens and their binary combinations on Sitophilus zeamais
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Langsi, D. J., primary, Tofel, H. K, additional, Fokunang, C. N., additional, Suh, C., additional, Eloh, K., additional, Caboni, P, additional, and Nukenine, E.N, additional
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- 2018
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9. Methods of payment for oral health care in Yaoundé
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Ashu Michael Agbor, Kaptue Bruno, Tedong Leonard, Reine Bahaya, Lumneh Alice, Sudeshni Naidoo, and Fokunang Charles
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methods of payment ,insurance ,oral health care ,direct payment ,yaoundé ,Public aspects of medicine ,RA1-1270 - Abstract
Payment for dental services is one of the key determinants of treatment options, access to health care, and treatment decisions. The ability to pay for services directly affects the quality of life of an individual and also their accessibility to oral health services. The aim of the present study was to identify the different methods of payment used to obtain oral health care in Yaoundé, Cameroon This was a cross-sectional descriptive study carried out in selected dental clinics in Yaoundé using convenient sampling between January 2021 and June 2021. Data was collected using a structured questionnaire. A total of 377 patients aged 8 to 83 years made up of 194 (51.46%) females and 183 (48.54%) males participated in the study. There is no government-assisted package for oral health care in Cameroon and more than two-thirds (66.84%) made direct payments or paid out of pocket without a refund from any insurance company. More than half 147 (58.33%) of the study population did not complete the planned dental care due to insufficient funds. Direct payments covered treatments such as scaling, restorations, root canal therapy, and dental extractions while prostheses (dentures, crowns, bridges, and implants) were only afforded by very few patients. The reasons for the inability to pay for dental services included financial difficulties 107 (72.97%) and lack of time 36 (24.49%). Only half 36 (50%) of the participants employed in the formal sector had access to health insurance and treatments like scaling, dental prosthesis, orthodontics, and dental implants were rarely provided by an insurance company. These procedures were considered to be very expensive with fluctuating prices and were viewed as being for aesthetic purposes. The majority 67 (93.06%) of payments through insurance reported being reimbursed aftercare. Two-thirds of 48 (71.64%) of the insured participants said it was difficult to get reimbursed due to the administrative bottlenecks and as such some preferred to pay out of pocket despite being insured. Late consultations encountered led to caries complications with 105 (52.24%) pulpitis. In general, financial difficulty was reported by 97 (48.26%) as the main reason for not being able to afford dental care. Oral diseases present a huge burden for children and adults due to the high cost of treatment limiting their accessibility and treatment options. There is a need to create compulsory health insurance to enhance greater access to oral health services to encourage the population to seek dental care timeously.
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- 2023
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10. Impact of Fungicide Application on Taro Leaf Blight Disease in Three Regions of Cameroon
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Manju, E, primary, Fokunang, C, additional, Mbong, G, additional, Tima, T, additional, Suh, C, additional, Tembe-Fokunang, E, additional, and Hanna, R, additional
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- 2017
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11. In vitro evaluation of the antimicrobial properties of Mallotus oppositifolium decoction leaf extracts and fractions
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Zintchem, R, Fankem, GO, Fokunang, C, Mkounga, P, Tembe, EA, Kamgang, R, Gatsing, D, and Dimo, T
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Folk medicine, phytochemical analysis, Mallotus oppositifolium diarrhea, antimicrobial - Abstract
In order to verify the in vitro antimicrobial properties of Mallotus oppositifolium (Euphorbiaceae), the qualitative phytochemical screening and the antimicrobial activities on Shigella dysenteriae A2, Salmonella typhi, Escherichia coli, Enterococcus faecalis, Staphyllococcus aureus and Candida albicans strains of the aqueous decoction (DEMO) hexane (HEMO) and methanol (MEMO) fractions of leaves were assessed. The screening was performed using colorimetric methods. The antimicrobial activity was carried out using disc diffusion assays. The minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) were determined by the dilution methods. The screening revealed the presence of metabolites such as alkaloids, flavonoids, phenolic compounds, tannins, saponins, lipids, carbohydrates, mucilages, proteins, triterpens and steroids. DEMO, HEMO, MEMO showed a concentration-dependent activity against Shigella dysenteriae A2 and Salmonella typhi, with inhibition zone ranging from 9.44±0.44 to 19.00±0.24 mm, 8.94±0.05 to 20.03±0.17 mm and 8.13±0.17 to 16.76±0.11 mm respectively. The MIC showed ranges from 0.25 to 1.00 mg.mL-1, 0.20 to 0.50 mg.mL-1 and 1.00 to 3.00 mg.mL-1, while the MBC ranged from 1.00 to 5.00 mg.mL-1, 0.50 to 1.00 and 3.00 to 10.00 mg.mL-1 respectively. The leaves decoction and fractions activity on the two strains showed promising activities to justify the use of the plant against diarrhoea in folk medicine.Keywords: Folk medicine, phytochemical analysis, Mallotus oppositifolium diarrhea, antimicrobial.
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- 2015
12. Risk factors of severe hepatotoxicity among HIV-1 infected individuals initiated on highly active antiretroviral therapy in the Northwest Region of Cameroon
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Lem Edith Abongwa, Anthony Kebira Nyamache, Fokunang Charles, Judith Torimiro, Nshom Emmanuel, Irénée Domkam, Mbu Eyongetah, Beriyuy Jude, Fung Holgar Mua, Sama Bella, Tankou Colman Tamboh, Erna Charlene Moungang, Victorine Ngum, and Paul Okemo
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Risk factors ,Liver enzymes ,HAART ,HIV-1 ,Hepatotoxicity ,Diseases of the digestive system. Gastroenterology ,RC799-869 - Abstract
Abstract Background Hepatotoxicity due to highly active antiretroviral therapy (HAART) has gained prominent attention since it can be affected by many factors. The aim of this study was to determine the prevalence of hepatotoxicity and related risk factors of severe hepatotoxicity following HAART initiation. Methods A total of 100 drug-naive patients aged between 18 and 61 years were recruited. They were put on Tenofovir/Lamivudine/Efavirenz [TDF/3TC/EFV] (64), Zidovudine/ Lamivudine/Efavirenz [AZT/3TC/EFV] (22), and Zidovudine/Lamivudine/Nevirapine AZT/3TC/NVP (14) and monitored for 6months and blood samples drawn.Alanine aminotransferases (ALT), aspartate aminotransferases (AST), and alkaline phosphatase (ALP) wereanalyzed by enzymatic methods and used to classify levels of hepatotoxicity. Results A total of 37(37%) and 49(49%) patients presented with hepatotoxicity while 15% and 28% had severe hepatotoxicity at 4 and 24 weeks respectively. Serum levels of all enzymes increased significantly (p = 0.001) with increased treatment duration. Univariate analysis revealed that the risk factor of developing severe hepatotoxicity was significantly greater in patients
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- 2022
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13. Antioxidative properties of Mallotus oppositifolium decoction leaves extract using in vitro models
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Zintchem, R, Njinkio, B, Kamgang, R, Fokunang, C, Tsala, DE, and Biwole Sida, M
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Traditional medicine, phytochemical analysis, antioxidant - Abstract
In an attempt to explain the scientific basis for the medicinal benefits of Mallotus oppositifolium (Euphorbiaceae), the phytochemical constituent and the antioxidative properties of the aqueous decoction leaves extract of the plant versus standard Vitamin C were assessed. The phytochemical analysis (screening and quantitative assay), the 1,1- Diphenyl-2-picrylhydrazyl (DPPH), Nitric oxide, and hydroxyl radicalscavenging, the reducing power, ferrous reducing antioxidant power (FRAP) and the β carotene bleaching of the extract were performed using colorimetric or spectrophotometric methods. Qualitative screening of the extract showed the presence of alkaloids, flavonoids, steroids, phenolic compounds, tannins, phlobatannins, saponins, lipids, carbohydrates, mucilages, and proteins. The phytochemical quantitative assay of the decoction extract revealed that the plant depicted flavonols (38.278 mg.g-1 catechin equivalent), tannins (23.13 mg.g-1 tannic acid equivalent), phenolics (13.73 mg.g-1 tannic acid content), flavonoids (10.62 mg.g-1 quercetin equivalent), proanthocyanidins (2.53 mg.g-1 quercetin equivalent) contents. Alkaloids and saponins content were 200 mg.g-1 and 285 mg.g-1, respectively. The ferric reducing antioxidant power (FRAP) of Mo extract and the IC50 of vitamin C were 228±0.4 mg.mL-1 and 592.0±0.8 mg.mL-1 , respectively. The DPPH radicalscavenging properties of IC50 of vitamin C was 480.0±0.8mg.mL-1 and that of Mo extract was 360.0±0.8 mg.mL-1. The IC50 of Mo’s reduce abilities was 39.2±0.8 mg.mL-1 and that of vitamin C was 320.0±0.8 mg.mL-1.The IC50 of the hydroxyl radical scavenging activity of Mo was 75.2±0,8 mg.mL-1 whereas that of IC50 of vitaminC was not defined. The nitric oxide radical scavenging activity of IC50 of Mo was 121.6±0.8 mg.mL-1 and that of the vitamin C was 130.4±0.8 mg.mL-1, respectively. The β carotene bleanching gives the IC50 of M. oppositifolium was 12,0±0,0 mg.mL-1 and for the vitamin C was 16.0±0,0 mg.mL-1. The decoction leaves of Mallotus oppositifolium (Mo) exhibited powerful antioxidative properties as vitamin C. The plant can be a source of antioxidative materials.Keywords: Traditional medicine, phytochemical analysis, antioxidant
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- 2014
14. The Role of Ethics in Public Health Clinical Research
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Fokunang, C. N., Tembe-Fokunang, E. A., Awah, P., Ngounoue, M. Djuidje, Chi, P. C., Ateudjieu, J., Langsi, R., Kaptue, Lazare, and Abena, O. M. T.
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- 2013
15. Mycotoxins : Quality Management, Prevention, Metabolism, Toxicity and Biomonitoring
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Fokunang, C. N.
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Medical / Public Health - Abstract
Mycotoxins: Quality Management, Prevention, Metabolism, Toxicity and Biomonitoring
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- 2011
16. Anticonvulsant activity of extracts from six Cameroonian plants traditionally used to treat epilepsy
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Dongmo Nguepi, MS, primary, Fokunang, C, additional, Fekam Boyom, F, additional, and Tazoacha, A, additional
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- 2015
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17. Mycelia Growth and Sporulation of Phytophthora colocasiae Isolates under Selected Conditions
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Mbong, G., primary, Fokunang, C., additional, Manju, E., additional, Njukeng, A., additional, Tembe-Fokunang, E., additional, and Hanna, Rachid, additional
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- 2015
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18. Pre-clinical Evaluation of the Hypotensive and Anti Atherogenic Activity of Hydroethanolic Extract of Eribroma oblongum (Malvaceae) Stem Bark on Wistar Rats Models
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Tsague, M., primary, Fokunang, C., additional, Ngameni, B., additional, Tembe-Fokunang, E., additional, Guedje, N., additional, Tom, E., additional, Dongmo, F., additional, Ngoupayo, J., additional, Sokeng, S., additional, Djomeni, Dzeufiet, additional, Oben, J., additional, Dimo, T., additional, Minkande, J., additional, and Tchaleu, B., additional
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- 2015
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19. Acute toxicity studies, antioxidant and in vitro antibacterial activities of extract from the barks of Ricinodendron heudoletti (Euphorbiaceae)
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Oyono, V.A, primary, Fokunang, C, additional, Assam-Assam, J. P, additional, Voundi, S., additional, Tsafack, P, additional, Mouafo, E. T, additional, Ngandjui, B.T, additional, and Beng, V. P, additional
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- 2014
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20. OP39 Evaluation of the hypoglycemic, hypolipidemic and anti alpha amylase effects of extracts of the twigs and fruits of Ficus ovata Vahl (Moraceae)
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Fouondo, M., primary, Oben, J., additional, and Fokunang, C., additional
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- 2014
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21. Human immunodeficiency virus type 1 ((HIV-1) subtypes in the northwest region, Cameroon
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Lem Edith Abongwa, Anthony Kebira Nyamache, Judith Ndongo Torimiro, Paul Okemo, and Fokunang Charles
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HIV-1 ,Genetic diversity ,Northwest region, reverse transcriptase ,Infectious and parasitic diseases ,RC109-216 - Abstract
Abstract Background The high genetic diversity of HIV-1 has been shown to influence the global distribution, disease progression, treatment success, and the development of an effective vaccine. Despite the low HIV prevalence in Cameroon, all the major HIV subtypes alongside several circulating recombinant forms (CRFs) and unique recombinant forms (URFs) have been reported in Cameroon. To date, HIV-1 diversity in some parts of Cameroon has been largely studied however, information on circulating HIV-1 subtypes in the Northwest region (NWR) of Cameroon is dearth. Therefore the aim of this study was to determine the current circulating HIV-1 subtypes among adults in the NWR of Cameroon. Methods The genetic analysis of the reverse transcriptase region of the pol gene was performed on 81 samples. The samples were collected from drug naïve patients aged between 18 and 61 years residing within the rural and urban towns in the NWR during the period between February and April 2016. Viral RNA was extracted from plasma, reverse-transcribed, further amplified by nested-PCR before sequencing using an in-house protocol. Generated sequences were then phylogenetically analyzed together with references using MEGA 7. Results Phylogenetic analysis revealed a broad viral diversity including CRF02 _AG (74.1%), F2 (7.4%), D (7.4%), G (3.7%), A1 (1.2%), CRF22_01A1 (2.5%), CRF06_cpx (1.2%), CRF09_cpx (1.2%), CRF11_cpx (1.2%). Three close epidemic clusters were found among F2 (1) and CRF02_AG (2) variants. For the first time we are reporting the CRF22_01A1 subtype in this region. Conclusion Our findings update HIV-1 subtypes information in Cameroon and uphold previous studies that CRF02_AG is the most prevalent subtype. This CRF02_AG subtype may have important public health, research, and clinical consequences.
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- 2019
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22. Rapid Screening Method of Cassava Cultivars for Resistance to Colletotrichum gloeosporioides f.sp. manihotis
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FOKUNANG, C. N., primary, DIXON, A. G. O., additional, IKOTUN, T., additional, AKEM, C. N., additional, and TEMBE, E. A., additional
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- 2002
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23. Field reaction of cassava genotypes to anthracnose, bacterial blight, cassava mosaic disease and their effects on yield
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Fokunang, C. N., primary, Ikotun, T., additional, Dixon, A. G.O., additional, and Akem, C. N., additional
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- 2000
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24. First Report of Colletotrichum gloeosporioides f. sp. manihotis, Cause of Cassava Anthracnose Disease, Being Seed-borne and Seed-Transmitted in Cassava
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Fokunang, C. N., primary, Ikotun, T., additional, Dixon, A. G. O., additional, and Akem, C. N., additional
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- 1997
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25. Cultural, morphological and pathogenic variability of Phytophthora colocasiae isolate from taro in Cameroon
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Manju, E.B., primary, Mbong, G.A., additional, Kinge, T.R., additional, Fokunang, E.T., additional, and Fokunang, C., additional
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- 1970
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26. Association between telomere length and Plasmodium falciparum malaria endemicity in sub-Saharan Africans.
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McQuillan MA, Verhulst S, Hansen MEB, Beggs W, Meskel DW, Belay G, Nyambo T, Mpoloka SW, Mokone GG, Fokunang C, Njamnshi AK, Chanock SJ, Aviv A, and Tishkoff SA
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- Adult, Female, Humans, Male, Middle Aged, Young Adult, Africa South of the Sahara epidemiology, Black People ethnology, Black People genetics, Endemic Diseases, Leukocytes metabolism, Plasmodium falciparum genetics, Plasmodium falciparum pathogenicity, Sub-Saharan African People, Telomere Homeostasis genetics, Botswana, Tanzania, Cameroon, Southern African People, Malaria, Falciparum genetics, Malaria, Falciparum epidemiology, Malaria, Falciparum parasitology, Telomere genetics
- Abstract
Leukocyte telomere length (LTL) varies significantly across human populations, with individuals of African ancestry having longer LTL than non-Africans. However, the genetic and environmental drivers of LTL variation in Africans remain largely unknown. We report here on the relationship between LTL, genetics, and a variety of environmental and climatic factors in ethnically diverse African adults (n = 1,818) originating from Botswana, Tanzania, Ethiopia, and Cameroon. We observe significant variation in LTL among populations, finding that the San hunter-gatherers from Botswana have the longest leukocyte telomeres and that the Fulani pastoralists from Cameroon have the shortest telomeres. Genetic factors explain ∼50% of LTL variation among individuals. Moreover, we observe a significant negative association between Plasmodium falciparum malaria endemicity and LTL while adjusting for age, sex, and genetics. Within Africa, adults from populations indigenous to areas with high malaria exposure have shorter LTL than those in populations indigenous to areas with low malaria exposure. Finally, we explore to what degree the genetic architecture underlying LTL in Africa covaries with malaria exposure., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2024 American Society of Human Genetics. All rights reserved.)
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- 2024
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27. Integrative functional genomic analyses identify genetic variants influencing skin pigmentation in Africans.
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Feng Y, Xie N, Inoue F, Fan S, Saskin J, Zhang C, Zhang F, Hansen MEB, Nyambo T, Mpoloka SW, Mokone GG, Fokunang C, Belay G, Njamnshi AK, Marks MS, Oancea E, Ahituv N, and Tishkoff SA
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- Humans, Alleles, Genomics, Pigmentation genetics, Polymorphism, Single Nucleotide genetics, Repressor Proteins genetics, Skin Pigmentation genetics, Melanins genetics, Albinism, Oculocutaneous
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Skin color is highly variable in Africans, yet little is known about the underlying molecular mechanism. Here we applied massively parallel reporter assays to screen 1,157 candidate variants influencing skin pigmentation in Africans and identified 165 single-nucleotide polymorphisms showing differential regulatory activities between alleles. We combine Hi-C, genome editing and melanin assays to identify regulatory elements for MFSD12, HMG20B, OCA2, MITF, LEF1, TRPS1, BLOC1S6 and CYB561A3 that impact melanin levels in vitro and modulate human skin color. We found that independent mutations in an OCA2 enhancer contribute to the evolution of human skin color diversity and detect signals of local adaptation at enhancers of MITF, LEF1 and TRPS1, which may contribute to the light skin color of Khoesan-speaking populations from Southern Africa. Additionally, we identified CYB561A3 as a novel pigmentation regulator that impacts genes involved in oxidative phosphorylation and melanogenesis. These results provide insights into the mechanisms underlying human skin color diversity and adaptive evolution., (© 2024. The Author(s), under exclusive licence to Springer Nature America, Inc.)
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- 2024
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28. Diverse African genomes reveal selection on ancient modern human introgressions in Neanderthals.
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Harris DN, Platt A, Hansen MEB, Fan S, McQuillan MA, Nyambo T, Mpoloka SW, Mokone GG, Belay G, Fokunang C, Njamnshi AK, and Tishkoff SA
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- Humans, Animals, Genome, Human, Gene Flow, Genomics, Africa South of the Sahara, Neanderthals genetics
- Abstract
Comparisons of Neanderthal genomes to anatomically modern human (AMH) genomes show a history of Neanderthal-to-AMH introgression stemming from interbreeding after the migration of AMHs from Africa to Eurasia. All non-sub-Saharan African AMHs have genomic regions genetically similar to Neanderthals that descend from this introgression. Regions of the genome with Neanderthal similarities have also been identified in sub-Saharan African populations, but their origins have been unclear. To better understand how these regions are distributed across sub-Saharan Africa, the source of their origin, and what their distribution within the genome tells us about early AMH and Neanderthal evolution, we analyzed a dataset of high-coverage, whole-genome sequences from 180 individuals from 12 diverse sub-Saharan African populations. In sub-Saharan African populations with non-sub-Saharan African ancestry, as much as 1% of their genomes can be attributed to Neanderthal sequence introduced by recent migration, and subsequent admixture, of AMH populations originating from the Levant and North Africa. However, most Neanderthal homologous regions in sub-Saharan African populations originate from migration of AMH populations from Africa to Eurasia ∼250 kya, and subsequent admixture with Neanderthals, resulting in ∼6% AMH ancestry in Neanderthals. These results indicate that there have been multiple migration events of AMHs out of Africa and that Neanderthal and AMH gene flow has been bi-directional. Observing that genomic regions where AMHs show a depletion of Neanderthal introgression are also regions where Neanderthal genomes show a depletion of AMH introgression points to deleterious interactions between introgressed variants and background genomes in both groups-a hallmark of incipient speciation., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2023 Elsevier Inc. All rights reserved.)
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- 2023
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29. Genomic characterization of HLA class I and class II genes in ethnically diverse sub-Saharan African populations: A report on novel HLA alleles.
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Pagkrati I, Duke JL, Mbunwe E, Mosbruger TL, Ferriola D, Wasserman J, Dinou A, Tairis N, Damianos G, Kotsopoulou I, Papaioannou J, Giannopoulos D, Beggs W, Nyambo T, Mpoloka SW, Mokone GG, Njamnshi AK, Fokunang C, Woldemeskel D, Belay G, Maiers M, Tishkoff SA, and Monos DS
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- Humans, Alleles, Africa South of the Sahara, Genes, MHC Class II, Genomics
- Abstract
HLA allelic variation has been well studied and documented in many parts of the world. However, African populations have been relatively under-represented in studies of HLA variation. We have characterized HLA variation from 489 individuals belonging to 13 ethnically diverse populations from rural communities from the African countries of Botswana, Cameroon, Ethiopia, and Tanzania, known to practice traditional subsistence lifestyles using next generation sequencing (Illumina) and long-reads from Oxford Nanopore Technologies. We identified 342 distinct alleles among the 11 HLA targeted genes: HLA-A, -B, -C, -DRB1, -DRB3, -DRB4, -DRB5, -DQA1, -DQB1, -DPA1, and -DPB1, with 140 of those alleles containing novel sequences that were submitted to the IPD-IMGT/HLA database. Sixteen of the 140 alleles contained novel content within the exonic regions of the genes, while 110 alleles contained novel intronic variants. Four alleles were found to be recombinants of already described HLA alleles and 10 alleles extended the sequence content of already described alleles. All 140 alleles include complete allelic sequence from the 5' UTR to the 3' UTR that are inclusive of all exons and introns. This report characterizes the HLA allelic variation from these individuals and describes the novel allelic variation present within these specific African populations., (© 2023 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)
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- 2023
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30. Pre-Treatment HIV Drug Resistance and Genetic Diversity in Cameroon: Implications for First-Line Regimens.
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Fokam J, Chenwi CA, Tala V, Takou D, Santoro MM, Teto G, Dambaya B, Anubodem F, Semengue ENJ, Beloumou G, Djupsa S, Assomo E, Fokunang C, Alteri C, Billong S, Bouba NP, Ajeh R, Colizzi V, Mbanya D, Ceccherini-Silberstein F, Perno CF, and Ndjolo A
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- Humans, Female, Adult, Middle Aged, Male, Cameroon epidemiology, Anti-Retroviral Agents therapeutic use, Genetic Variation, Drug Resistance, Viral genetics, Anti-HIV Agents pharmacology, Anti-HIV Agents therapeutic use, HIV Infections drug therapy, HIV Infections epidemiology, HIV-1 genetics
- Abstract
The efficacy of first-line antiretroviral therapy (ART) may be hampered by the presence of HIV drug resistance (HIVDR). We described HIV-1 pre-treatment drug resistance (PDR) patterns, effect of viral clades on PDR, and programmatic implications on first-line regimens in Cameroon. A sentinel surveillance of PDR was conducted from 2014 to 2019. Sequencing of HIV-1 protease and reverse transcriptase was performed, and HIVDR was interpreted using Stanford HIVdb.v.9.4. In total, 379 sequences were obtained from participants (62% female, mean age 36 ± 10 years). The overall PDR rate was 15.0% [95% CI: 11.8-19.0] nationwide, with significant disparity between regions ( p = 0.03). NNRTI PDR was highest (12.4%), of which 7.9% had DRMs to EFV/NVP. Two regions had EFV/NVP PDR above the 10% critical threshold, namely the Far North (15%) and East (10.9%). Eighteen viral strains were identified, predominated by CRF02_AG (65.4%), with no influence of genetic diversity PDR occurrence. TDF-3TC-DTG predictive efficacy was superior (98.4%) to TDF-3TC-EFV (92%), p < 0.0001. The overall high rate of PDR in Cameroon, not substantially affected by the wide HIV-1 genetic diversity, underscores the poor efficacy of EFV/NVP-based first-line ART nationwide, with major implications in two regions of the country. This supports the need for a rapid transition to NNRTI-sparing regimens, with TDF-3TC-DTG having optimal efficacy at the programmatic level.
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- 2023
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31. Impact of natural selection on global patterns of genetic variation and association with clinical phenotypes at genes involved in SARS-CoV-2 infection.
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Zhang C, Verma A, Feng Y, Melo MCR, McQuillan M, Hansen M, Lucas A, Park J, Ranciaro A, Thompson S, Rubel MA, Campbell MC, Beggs W, Hirbo J, Wata Mpoloka S, George Mokone G, Nyambo T, Wolde Meskel D, Belay G, Fokunang C, Njamnshi AK, Omar SA, Williams SM, Rader DJ, Ritchie MD, de la Fuente-Nunez C, Sirugo G, and Tishkoff SA
- Subjects
- Africa, Angiotensin-Converting Enzyme 2 genetics, Genetic Variation, Humans, Phenotype, SARS-CoV-2 genetics, Selection, Genetic, COVID-19 genetics
- Abstract
Human genomic diversity has been shaped by both ancient and ongoing challenges from viruses. The current coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has had a devastating impact on population health. However, genetic diversity and evolutionary forces impacting host genes related to SARS-CoV-2 infection are not well understood. We investigated global patterns of genetic variation and signatures of natural selection at host genes relevant to SARS-CoV-2 infection (angiotensin converting enzyme 2 [ACE2], transmembrane protease serine 2 [TMPRSS2], dipeptidyl peptidase 4 [DPP4], and lymphocyte antigen 6 complex locus E [LY6E]). We analyzed data from 2,012 ethnically diverse Africans and 15,977 individuals of European and African ancestry with electronic health records and integrated with global data from the 1000 Genomes Project. At ACE2, we identified 41 nonsynonymous variants that were rare in most populations, several of which impact protein function. However, three nonsynonymous variants (rs138390800, rs147311723, and rs145437639) were common among central African hunter-gatherers from Cameroon (minor allele frequency 0.083 to 0.164) and are on haplotypes that exhibit signatures of positive selection. We identify signatures of selection impacting variation at regulatory regions influencing ACE2 expression in multiple African populations. At TMPRSS2, we identified 13 amino acid changes that are adaptive and specific to the human lineage compared with the chimpanzee genome. Genetic variants that are targets of natural selection are associated with clinical phenotypes common in patients with COVID-19. Our study provides insights into global variation at host genes related to SARS-CoV-2 infection, which have been shaped by natural selection in some populations, possibly due to prior viral infections.
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- 2022
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32. Redondovirus Diversity and Evolution on Global, Individual, and Molecular Scales.
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Taylor LJ, Dothard MI, Rubel MA, Allen AA, Hwang Y, Roche AM, Graham-Wooten J, Fitzgerald AS, Khatib LA, Ranciaro A, Thompson SR, Beggs WR, Campbell MC, Mokone GG, Mpoloka SW, Fokunang C, Njamnshi AK, Mbunwe E, Woldemeskel D, Belay G, Nyambo T, Tishkoff SA, Collman RG, and Bushman FD
- Subjects
- Africa epidemiology, Biodiversity, Critical Illness, DNA Virus Infections epidemiology, DNA-Binding Proteins metabolism, Evolution, Molecular, Genome, Viral, Humans, Metagenomics, Periodontitis virology, Phylogeny, Prevalence, Rural Population, United States epidemiology, Viral Proteins metabolism, DNA Virus Infections virology, DNA Viruses classification, DNA Viruses genetics, DNA Viruses metabolism, Mouth virology, Respiratory System virology, Saliva virology
- Abstract
Redondoviridae is a newly established family of circular Rep-encoding single-stranded (CRESS) DNA viruses found in the human ororespiratory tract. Redondoviruses were previously found in ∼15% of respiratory specimens from U.S. urban subjects; levels were elevated in individuals with periodontitis or critical illness. Here, we report higher redondovirus prevalence in saliva samples: four rural African populations showed 61 to 82% prevalence, and an urban U.S. population showed 32% prevalence. Longitudinal, limiting-dilution single-genome sequencing revealed diverse strains of both redondovirus species ( Brisavirus and Vientovirus ) in single individuals, persistence over time, and evidence of intergenomic recombination. Computational analysis of viral genomes identified a recombination hot spot associated with a conserved potential DNA stem-loop structure. To assess the possible role of this site in recombination, we carried out in vitro studies which showed that this potential stem-loop was cleaved by the virus-encoded Rep protein. In addition, in reconstructed reactions, a Rep-DNA covalent intermediate was shown to mediate DNA strand transfer at this site. Thus, redondoviruses are highly prevalent in humans, found in individuals on multiple continents, heterogeneous even within individuals and encode a Rep protein implicated in facilitating recombination. IMPORTANCE Redondoviridae is a recently established family of DNA viruses predominantly found in the human respiratory tract and associated with multiple clinical conditions. In this study, we found high redondovirus prevalence in saliva from urban North American individuals and nonindustrialized African populations in Botswana, Cameroon, Ethiopia, and Tanzania. Individuals on both continents harbored both known redondovirus species. Global prevalence of both species suggests that redondoviruses have long been associated with humans but have remained undetected until recently due to their divergent genomes. By sequencing single redondovirus genomes in longitudinally sampled humans, we found that redondoviruses persisted over time within subjects and likely evolve by recombination. The Rep protein encoded by redondoviruses catalyzes multiple reactions in vitro , consistent with a role in mediating DNA replication and recombination. In summary, we identify high redondovirus prevalence in humans across multiple continents, longitudinal heterogeneity and persistence, and potential mechanisms of redondovirus evolution by recombination.
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- 2021
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33. Impact of natural selection on global patterns of genetic variation, and association with clinical phenotypes, at genes involved in SARS-CoV-2 infection.
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Zhang C, Verma A, Feng Y, Melo MCR, McQuillan M, Hansen M, Lucas A, Park J, Ranciaro A, Thompson S, Rubel MA, Campbell MC, Beggs W, Hirbo J, Mpoloka SW, Mokone GG, Nyambo T, Meskel DW, Belay G, Fokunang C, Njamnshi AK, Omar SA, Williams SM, Rader D, Ritchie MD, de la Fuente Nunez C, Sirugo G, and Tishkoff S
- Abstract
We investigated global patterns of genetic variation and signatures of natural selection at host genes relevant to SARS-CoV-2 infection ( ACE2 , TMPRSS2 , DPP4 , and LY6E ). We analyzed novel data from 2,012 ethnically diverse Africans and 15,997 individuals of European and African ancestry with electronic health records, and integrated with global data from the 1000GP. At ACE2 , we identified 41 non-synonymous variants that were rare in most populations, several of which impact protein function. However, three non-synonymous variants were common among Central African hunter-gatherers from Cameroon and are on haplotypes that exhibit signatures of positive selection. We identify strong signatures of selection impacting variation at regulatory regions influencing ACE2 expression in multiple African populations. At TMPRSS2 , we identified 13 amino acid changes that are adaptive and specific to the human lineage. Genetic variants that are targets of natural selection are associated with clinical phenotypes common in patients with COVID-19., Competing Interests: Declaration of Interests No conflict of interest
- Published
- 2021
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34. Preinvasive cervical lesions and high prevalence of human papilloma virus among pregnant women in Cameroon.
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Doh G, Mkong E, Ikomey GM, Obasa AE, Mesembe M, Fokunang C, and Jacobs GB
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Introduction: With the exception of breast cancer, gynecologic neoplasms constitute the most common cancers that complicate pregnancy. Pregnancy therefore presents a window of opportunity for all pregnant women who do not take part in routine free cervical cancer screening program to undergo a free voluntary cytological test and human papillomavirus (HPV) DNA testing. This study aimed to determine prevalent HPV genotypes among pregnant women using exfoliated cells from cervical swabs and determine risk factors responsible for the upsurge of cervical precancerous lesions., Methods: In a cross-sectional study conducted from October 2017 to March 2018, a total of 482 pregnant women were enrolled. Cervical swabs and samples for cytology were collected from each enrolled participant during their routine prenatal consultation. The Papanicolaou's (Pap) staining technique was performed and all cervical swab samples were amplified through conventional PCR. HPV genotypes were identified using the Roche Linear Array Genotyping Assay. SAS 9.2 software (SAS Institute Inc., USA) was used for statistical analysis and p values >0.05 were considered significant., Results: Among the 482 participants, 354 (73.4%) had normal cytology and 128 (26.6%) had abnormal cytology. HPV DNA was identified in 62/464 (13.4%). The most prominent HPV types identified were HPV 16 (24%), HPV 18 (36.4%), HPV 45 (28%), HPV 53 (18.9%) and HPV 67 (24.3%). Early intercourse, number of sexual partners and age at first pregnancy were some of the risk factors that influenced the etiology of preinvasive cervical lesion., Conclusions: Prevalent HPV types identified in our study were HPV 16, 18, 45, 53 and 67. Organizing effective screening programs in prenatal care facilities is crucial in order to detect prevalent HR-HPV types and precursors for cervical lesions. The addition of HPV vaccination in the national immunization program with focus on the different epidemiological HPV genotypes circulating in the country is warranted., Competing Interests: Conflicts of interest: None to declare., (GERMS.)
- Published
- 2021
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35. Lifestyle and the presence of helminths is associated with gut microbiome composition in Cameroonians.
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Rubel MA, Abbas A, Taylor LJ, Connell A, Tanes C, Bittinger K, Ndze VN, Fonsah JY, Ngwang E, Essiane A, Fokunang C, Njamnshi AK, Bushman FD, and Tishkoff SA
- Subjects
- Animals, Cameroon, Diet, Paleolithic, Humans, Life Style, Machine Learning, Metagenome, RNA, Ribosomal, 16S genetics, Farmers statistics & numerical data, Gastrointestinal Microbiome, Host-Parasite Interactions immunology, Nematoda physiology, Parasite Load
- Abstract
Background: African populations provide a unique opportunity to interrogate host-microbe co-evolution and its impact on adaptive phenotypes due to their genomic, phenotypic, and cultural diversity. We integrate gut microbiome 16S rRNA amplicon and shotgun metagenomic sequence data with quantification of pathogen burden and measures of immune parameters for 575 ethnically diverse Africans from Cameroon. Subjects followed pastoralist, agropastoralist, and hunter-gatherer lifestyles and were compared to an urban US population from Philadelphia., Results: We observe significant differences in gut microbiome composition across populations that correlate with subsistence strategy and country. After these, the variable most strongly associated with gut microbiome structure in Cameroonians is the presence of gut parasites. Hunter-gatherers have high frequencies of parasites relative to agropastoralists and pastoralists. Ascaris lumbricoides, Necator americanus, Trichuris trichiura, and Strongyloides stercoralis soil-transmitted helminths ("ANTS" parasites) significantly co-occur, and increased frequency of gut parasites correlates with increased gut microbial diversity. Gut microbiome composition predicts ANTS positivity with 80% accuracy. Colonization with ANTS, in turn, is associated with elevated levels of TH1, TH2, and proinflammatory cytokines, indicating an association with multiple immune mechanisms. The unprecedented size of this dataset allowed interrogation of additional questions-for example, we find that Fulani pastoralists, who consume high levels of milk, possess an enrichment of gut bacteria that catabolize galactose, an end product of lactose metabolism, and of bacteria that metabolize lipids., Conclusions: These data document associations of bacterial microbiota and eukaryotic parasites with each other and with host immune responses; each of these is further correlated with subsistence practices.
- Published
- 2020
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36. Programme quality indicators of HIV drug resistance among adolescents in urban versus rural settings of the centre region of Cameroon.
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Fokam J, Nangmo A, Wandum C, Takou D, Santoro MM, Nlend AN, Ateba FN, Ndombo PK, Kamgaing N, Kamta C, Essiane A, Lambo V, Fokunang C, Mbanya D, Colizzi V, Perno CF, and Ndjolo A
- Subjects
- Adolescent, Anti-Retroviral Agents therapeutic use, Cameroon epidemiology, Child, Female, HIV Infections drug therapy, HIV Infections epidemiology, Humans, Male, Medication Adherence statistics & numerical data, Viral Load drug effects, Young Adult, Drug Resistance, Viral, HIV-1 drug effects, Quality Indicators, Health Care statistics & numerical data, Rural Population statistics & numerical data, Urban Population statistics & numerical data
- Abstract
Background: The high rate of mortality among HIV-vertically infected adolescents might be favoured by HIV drug resistance (HIVDR) emergence, which calls for timeous actions in this underserved population. We thus sought to evaluate program quality indicators (PQIs) of HIVDR among HIV-vertically infected adolescents on antiretroviral therapy (ART)., Methods: A study was conducted in the Centre region of Cameroon among adolescents (10-19 years) receiving ART in two urban (The Mother-Child Centre of the Chantal BIYA Foundation, the National Social Welfare Hospital) and three rural (Mfou District Hospital, Mbalmayo District Hospital and Nkomo Medical Center) health facilities. Following an exhaustive sampling from ART registers, patient medical files and pharmacy records, data was abstracted for seven PQIs: on-time drug pick-up; retention in care; pharmacy stock outs; dispensing practices; viral load coverage; viral suppression and adequate switch to second-line. Performance in PQIs was interpreted following the WHO-recommended thresholds (desirable, fair and/or poor); with p < 0.05 considered significant., Results: Among 967 adolescents (888 urban versus 79 rural) registered in the study sites, validated data was available for 633 (554 in urban and 79 in rural). Performance in the urban vs. rural settings was respectively: on-time drug pick-up was significantly poorer in rural (79% vs. 46%, p = 0.00000006); retention in care was fair in urban (80% vs. 72%, p = 0.17); pharmacy stock outs was significantly higher in urban settings (92% vs. 50%, p = 0.004); dispensing practices was desirable (100% vs. 100%, p = 1.000); viral load coverage was desirable only in urban sites (84% vs. 37%, p < 0.0001); viral suppression was poor (33% vs. 53%, p = 0.08); adequate switch to second-line varied (38.1% vs. 100%, p = 0.384)., Conclusion: Among adolescents on ART in Cameroon, dispensing practices are appropriate, while adherence to ART program and viral load coverage are better in urban settings. However, in both urban and rural settings, pharmacy stock outs, poor viral suppression and inadequate switch to second-line among adolescents require corrective public-health actions to limit HIVDR and to improve transition towards adult care in countries sharing similar programmatic features.
- Published
- 2020
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37. Near full genome characterization of HIV-1 unique recombinant forms in Cameroon reveals dominant CRF02_AG and F2 recombination patterns.
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Banin AN, Tuen M, Bimela JS, Tongo M, Zappile P, Khodadadi-Jamayran A, Nanfack AJ, Okonko IO, Meli J, Wang X, Mbanya D, Ngogang J, Gorny MK, Heguy A, Fokunang C, and Duerr R
- Subjects
- Anti-HIV Agents therapeutic use, Cameroon epidemiology, Female, Genome, Viral, HIV Infections drug therapy, Humans, Longitudinal Studies, Mutation, Phylogeny, Polymerase Chain Reaction, HIV Infections epidemiology, HIV Infections virology, HIV Seropositivity, HIV-1 genetics, Reassortant Viruses genetics
- Abstract
Introduction: In Cameroon, a manifold diversity of HIV strains exists with CRF02_AG and unique recombinant forms (URFs) being the predominant strains. In recent years, a steady increase in URFs and clade F2 viruses has been monitored through partial genome sequencing. There is an information gap in the characterization of emerging URFs along the full genome, which is needed to address the challenges URFs pose towards diagnosis, treatment and HIV-1 vaccine design., Method: Eighteen Cameroonian URFs from samples collected between the years 2000 and 2015 were studied using a newly developed near full genome sequencing (NFGS) protocol based on variable nested RT-PCRs with a versatile primer set. Near full genomes were characterized for recombination patterns and sequence signatures with possible impact on antiretroviral treatment or Env-directed immune responses. Third-generation sequencing (3GS) of near full or half genomes (HGs) gave insight into intra-patient URF diversity., Results: The characterized URFs were composed of a broad variety of subtypes and recombinants including A, F, G, CRF01_AE, CRF02_AG and CRF22_01A1. Phylogenetic analysis unveiled dominant CRF02_AG and F2 recombination patterns. 3GS indicated a high intra-patient URF diversity with up to four distinct viral sub-populations present in plasma at the same time. URF pol genomic analysis revealed a number of accessory drug resistance mutations (DRMs) in the ART-naïve participants. Genotypic env analysis suggests CCR5 usage in 14/18 samples and identified deviations at residues, critical for gp120/gp41 interphase and CD4 binding site broadly neutralizing antibodies in more than half of the studied URFs. V1V2 sites of immune pressure in the human RV144 vaccine study varied in more than a third of URFs., Conclusions: This study identified novel mosaic patterns in URFs in Cameroon. In line with the regional predominance of CRF_02AG and the increased prevalence of clade F2, prominent CRF_02AG and F2 background patterns were observed underlying the URFs. In the context of the novel mosaic genomes, the impact of the identified accessory DRMs and Env epitope variations on treatment and immune control remains elusive. The evolving diversity of HIV-1 URFs in Cameroon requires continuous monitoring to respond to the increasing challenges for diagnosis, antiretroviral treatment and prevention., (© 2019 The Authors. Journal of the International AIDS Society published by John Wiley & Sons Ltd on behalf of the International AIDS Society.)
- Published
- 2019
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38. Development of a Versatile, Near Full Genome Amplification and Sequencing Approach for a Broad Variety of HIV-1 Group M Variants.
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Banin AN, Tuen M, Bimela JS, Tongo M, Zappile P, Khodadadi-Jamayran A, Nanfack AJ, Meli J, Wang X, Mbanya D, Ngogang J, Heguy A, Nyambi PN, Fokunang C, and Duerr R
- Subjects
- Cloning, Molecular methods, DNA Primers genetics, Genotype, HIV Infections virology, HIV-1 classification, Humans, Plasma virology, HIV-1 genetics, High-Throughput Nucleotide Sequencing methods, Nucleic Acid Amplification Techniques methods, Whole Genome Sequencing methods
- Abstract
Near full genome sequencing (NFGS) of HIV-1 is required to assess the genetic composition of HIV-1 strains comprehensively. Population-wide, it enables a determination of the heterogeneity of HIV-1 and the emergence of novel/recombinant strains, while for each individual it constitutes a diagnostic instrument to assist targeted therapeutic measures against viral components. There is still a lack of robust and adaptable techniques for efficient NFGS from miscellaneous HIV-1 subtypes. Using rational primer design, a broad primer set was developed for the amplification and sequencing of diverse HIV-1 group M variants from plasma. Using pure subtypes as well as diverse, unique recombinant forms (URF), variable amplicon approaches were developed for NFGS comprising all functional genes. Twenty-three different genomes composed of subtypes A (A1), B, F (F2), G, CRF01_AE, CRF02_AG, and CRF22_01A1 were successfully determined. The NFGS approach was robust irrespective of viral loads (≥306 copies/mL) and amplification method. Third-generation sequencing (TGS), single genome amplification (SGA), cloning, and bulk sequencing yielded similar outcomes concerning subtype composition and recombinant breakpoint patterns. The introduction of a simple and versatile near full genome amplification, sequencing, and cloning method enables broad application in phylogenetic studies of diverse HIV-1 subtypes and can contribute to personalized HIV therapy and diagnosis., Competing Interests: The authors declare no conflict of interest.
- Published
- 2019
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39. Identification and quantification of 19 pharmaceutical active compounds and metabolites in hospital wastewater in Cameroon using LC/QQQ and LC/Q-TOF.
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Mayoudom EVT, Nguidjoe E, Mballa RN, Tankoua OF, Fokunang C, Anyakora C, and Blackett KN
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- Cameroon, Hospitals, Humans, Mass Spectrometry methods, Pharmaceutical Preparations metabolism, Wastewater chemistry, Chromatography, High Pressure Liquid methods, Environmental Monitoring methods, Wastewater analysis, Water Pollutants, Chemical analysis
- Abstract
Human pharmaceutical residues are a serious environmental concern. They have been reported to have eco, geno, and human toxic effects, and thus their importance as micropollutants cannot be ignored. These have been studied extensively in Europe and North America. However, African countries are still lagging behind in research on these micropollutants. In this study, the wastewaters of the University Teaching Hospital of Yaoundé (UTHY) were screened for the presence of active pharmaceutical ingredients and their metabolites. The screening was carried out using two methods: high-performance liquid chromatography coupled to a triple quadrupole analyzer (LC/QQQ) and high-performance coupled to a mass spectrometer with a time of flight analyzer (LC/Q-TOF). A total of 19 active pharmaceutical ingredients and metabolites were identified and quantified. The compounds identified include paracetamol (211.93 μg/L), ibuprofen (141 μg/L), tramadol (76 μg/L), O-demethyltramadol (141 μg/L), erythromycinanhydrate (7 μg/L), ciprofloxacin (24 μg/L), clarinthromycine (0.088 μg/L), azitromycine (0.39 μg/L), sulfamethoxazole 0.16 μg/L), trimetoprime (0.27 μg/L), caffeine (5.8 μg/L), carnamaeepine (0.94 μg/L), atenolol (0.43 μg/L), propranolol (0.3 μg/L), cimetidine (34 μg/L), hydroxy omeprazole (5 μg/L), diphenhydramine (0.38 μg/L), metformine (154 μg/L), and sucralose (13.07 μg/L).
- Published
- 2018
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40. Investigating zoonotic infection barriers to ape Plasmodium parasites using faecal DNA analysis.
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Loy DE, Rubel MA, Avitto AN, Liu W, Li Y, Learn GH, Ranciaro A, Mbunwe E, Fokunang C, Njamnshi AK, Sharp PM, Tishkoff SA, and Hahn BH
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- Animals, Cameroon epidemiology, Humans, Malaria epidemiology, Malaria parasitology, Phylogeny, Plasmodium genetics, DNA, Protozoan isolation & purification, Feces parasitology, Hominidae parasitology, Malaria veterinary, Plasmodium classification, Zoonoses
- Abstract
African apes are endemically infected with numerous Plasmodium spp. including close relatives of human Plasmodium falciparum, Plasmodium vivax, Plasmodium ovale, and Plasmodium malariae. Although these ape parasites are not believed to pose a zoonotic threat, their ability to colonise humans has not been fully explored. In particular, it remains unknown whether ape parasites are able to initiate exo-erythrocytic replication in human hepatocytes following the bite of an infective mosquito. Since animal studies have shown that liver stage infection can result in the excretion of parasite nucleic acids into the bile, we screened faecal samples from 504 rural Cameroonians for Plasmodium DNA. Using pan-Laverania as well as P. malariae- and P. vivax-specific primer sets, we amplified human P. falciparum (n = 14), P. malariae (n = 1), and P. ovale wallikeri (n = 1) mitochondrial sequences from faecal DNA of 15 individuals. However, despite using an intensified PCR screening approach we failed to detect ape Laverania, ape P. vivax or ape P. malariae parasites in these same subjects. One faecal sample from a hunter-gatherer contained a sequence closely related to the porcupine parasite Plasmodium atheruri. Since this same faecal sample also contained porcupine mitochondrial DNA, but a matching blood sample was Plasmodium-negative, it is likely that this hunter-gatherer consumed Plasmodium-infected bushmeat. Faecal Plasmodium detection was not secondary to intestinal bleeding and/or infection with gastrointestinal parasites, but indicative of blood parasitaemia. Quantitative PCR identified 26-fold more parasite DNA in the blood of faecal Plasmodium-positive than faecal Plasmodium-negative individuals (P = 0.01). However, among blood-positive individuals only 10% - 20% had detectable Plasmodium sequences in their stool. Thus, faecal screening of rural Cameroonians failed to uncover abortive ape Plasmodium infections, but detected infection with human parasites, albeit with reduced sensitivity compared with blood analysis., (Copyright © 2018 Australian Society for Parasitology. Published by Elsevier Ltd. All rights reserved.)
- Published
- 2018
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41. Pre-vaccine circulating group a rotavirus strains in under 5 years children with acute diarrhea during 1999-2013 in Cameroon.
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Ndombo PK, Ndze VN, Fokunang C, Ashukem TN, Boula A, Kinkela MN, Ndode CE, Seheri ML, Bowen MD, Waku-Kouomou D, and Esona MD
- Abstract
The aim of this review was to assess all the studies on rotavirus G and P characterization during the pre-vaccine period (1999-2013) in Cameroon to have a better basis for post-vaccine introduction evaluations. A retrospective study was done through a comprehensive review of published (PubMed, Google Scholar) and accessible unpublished data on rotavirus G and P genotypes circulating in five regions of Cameroon. Descriptive data were expressed as frequencies tables and proportions. A total of 1844 rotavirus positive cases were analyzed. In all, 1534 strains were characterized for the P (VP4) specificity. Six different VP4 genotypes were observed, including P [4], P [6], P [8], P [9], P [10] and P [14]. The most predominant P genotypes were P [8] at 42.6%, and P [6] at 37.9%. Mixed infections were observed at 5.3%, whereas 4.1% of the strains were P non-typeable. A total of 1518 rotavirus strains were characterized for the G (VP7) specificity. VP7 genotypes G1, G2, G3, G4, G5, G6, G8, G9, G10 and G12 were observed. G1 (35.3%), G3 (19.5%), G2 (14.9%) and G12 (10.1%) were the predominant G genotypes while G5 and G10 were least prevalent at 0.06% each. Approximately 5.1% of all strains were G non-typeable whereas 5.3% were mixed G genotypes. A total of 1472 strains were characterized for both G and P genes, from which 38 different G-P combinations were observed. Overall, G1P [8] (22%) was identified as the predominant rotavirus strain circulating in Cameroon followed by G3P [6] (15%). In conclusion, we observed that the genotypes identified in Cameroon during 1999-2013 were partially covered by the two WHO recommended rotavirus vaccines. This review provides comprehensive up-to-date information on rotavirus strain surveillance in Cameroon during the pre-vaccination era., Competing Interests: Disclosure of potential conflicts of interest No potential conflicts of interest were disclosed.
- Published
- 2017
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42. Antibacterial activities and toxicological study of the aqueous extract from leaves of Alchornea cordifolia (Euphorbiaceae).
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Djimeli MN, Fodouop SPC, Njateng GSS, Fokunang C, Tala DS, Kengni F, and Gatsing D
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- Animals, Anti-Bacterial Agents chemistry, Anti-Bacterial Agents isolation & purification, Anti-Bacterial Agents toxicity, Escherichia coli drug effects, Escherichia coli growth & development, Escherichia coli Infections drug therapy, Escherichia coli Infections microbiology, Female, Humans, Male, Mice, Phytotherapy, Plant Extracts chemistry, Plant Extracts isolation & purification, Plant Extracts toxicity, Plant Leaves chemistry, Rats, Rats, Wistar, Anti-Bacterial Agents administration & dosage, Euphorbiaceae chemistry, Plant Extracts administration & dosage
- Abstract
Background: A. cordifolia is a plant widely used in Africa to solve many health problems. In Cameroon, it is used in the treatment of urogenital infections. As a continuation of our search for pharmacologically active agents from natural sources, the antimicrobial activity of A. cordifolia leaf extracts against E. coli and the toxicity of this extract were investigated., Methods: The antibacterial activity of the aqueous extract from leaves of Alchornea cordifolia was carried out in vitro on Escherichia coli, as well as in vivo on E. coli-infected rat model. Phytochemical screening was performed using standard methods. The acute toxicity was investigated in mice, while at the end of treatment of infected rats, some biochemical, hematological and histological markers of toxicity were evaluated., Results: The extract exhibited a bacteriostatic activity with MIC value of 1500 μg/ml. Phytochemical screening revealed the presence of phenols, tannins, triterpens, flavonoids, alkaloids, anthraquinones, anthocyanins, saponins and coumarins in the extract. The acute toxicity study showed LD
50 values of 8.6 g/kg and 3.8 g/kg in male and female mice respectively. In vivo, the oral administration of the extract showed a dose-dependent decrease of the bacterial load as the extract at 232, 112 and 58 g/kg were able to eradicate the infection after 9, 11 and 13 days of treatment. The infected rats showed a significant (p < 0.05) increase in the level of serum creatinine, ALAT, white blood cells, and a significant (p < 0.05) decrease in the level of food and water intake, the relative weight of lungs, heart and spleen. In the treated rats, a significant (p < 0.05) increase in food and water intake and ALAT was observed at the doses of 116 and 232 mg/kg. A decrease in the red blood cells count and serum protein levels was also observed. These observations corroborate liver damages as revealed by the histopathological examination of the cross sections of this organ., Conclusion: The results of this assay thus showed that the extract of A. cordifolia is bacteriostatic, therapeutic at 58 g/kg bw and may be considered as slightly and almost non-toxic on females and males mice respectively.- Published
- 2017
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43. Intestinal carriage of Extended Spectrum Beta-Lactamase producing E. coli in women with urinary tract infections, Cameroon.
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Djuikoue IC, Woerther PL, Toukam M, Burdet C, Ruppé E, Gonsu KH, Fokunang C, El Mniai A, Larissa K, Pieme AC, Mboupaing MG, Kakam CM, Fogang HK, Andremont A, and Ngogang J
- Subjects
- Adolescent, Adult, Aged, Aged, 80 and over, Cameroon epidemiology, Carrier State microbiology, Child, Child, Preschool, Community-Acquired Infections, Cross-Sectional Studies, Disk Diffusion Antimicrobial Tests, Escherichia coli enzymology, Escherichia coli Infections epidemiology, Female, Humans, Infant, Male, Mass Spectrometry, Middle Aged, Pregnancy, Prevalence, Young Adult, Carrier State epidemiology, Escherichia coli isolation & purification, Escherichia coli Infections microbiology, Feces microbiology, Urinary Tract Infections microbiology, beta-Lactamases metabolism
- Abstract
Introduction: During the last decade, the prevalence of the intestinal carriage of extended spectrum beta-lactamases - producing Escherichia coli (ESBL-E. coli) has continued to increase worldwide in the community, especially in developing countries. Hence, we undertook a study to determine the ESBL-E. coli fecal carriage rate and the associated risk factors in Cameroonian women., Methodology: A total of 86 women suspected of community-acquired urinary tract infections (UTI) were included in 10 health structures from May 2011 to April 2012. After filling a questionnaire, they provided a stool sample that was plated on selective media for ESBL producing bacteria. The identification of strains was obtained with mass spectrometry and the antibiotic susceptibility by disk diffusion in agar media. The ESBL type was determined by PCR. The relative abundance of ESBL-E. coli was measured for positive samples. Eventually, the presence of antibiotics in stool was assessed., Results: The carriage rate of ESBL-E. coli was 57/86 (66.3%). Phenotypic and molecular characterization showed that all ESBL-E. coli strains contained group 1 CTX-M enzymes. Multivariate analysis showed that ESBL-E. coli fecal carriage was associated with the presence of antibiotics in stools (p < 0.05). Although not significant, mean ESBL relative abundance tended to be higher in patients with antibiotic exposure., Conclusions: Our results show that the carriage of ESBL-E. coli fecal carriage in women with UTI suspicion from the Cameroonian community is extremely high and associated with recent antibiotic intake.
- Published
- 2016
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44. Antityphoid properties and toxicity evaluation of Harungana madagascariensis Lam (Hypericaceae) aqueous leaf extract.
- Author
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Kengni F, Fodouop SP, Tala DS, Djimeli MN, Fokunang C, and Gatsing D
- Subjects
- Animals, Anti-Bacterial Agents pharmacology, Cameroon, Cholesterol blood, Ethnopharmacology, Female, Lipid Metabolism drug effects, Liver pathology, Liver Function Tests, Male, Microbial Sensitivity Tests, Necrosis, Plant Extracts pharmacology, Plant Leaves chemistry, Rats, Rats, Wistar, Salmonella typhimurium, Typhoid Fever microbiology, Anti-Bacterial Agents therapeutic use, Clusiaceae chemistry, Plant Extracts therapeutic use, Typhoid Fever drug therapy
- Abstract
Context: Harungana madagascariensis Lam is commonly used in Cameroonian folk medicine for the treatment of malaria and typhoid fever., Objective: To investigate the therapeutic potentials of H. madagascariensis aqueous leaf extract for the treatment of salmonellosis (e.g. typhoid fever, gastroenteritis)., Materials and Methods: A Salmonella Typhimurium-infected rat model was used. The faeces of these rats were analysed for viable Salmonella Typhimurium before and after infection, and during the treatment period. The physiological, biochemical and histopathological markers of possible side effects of the extract were also studied using standard methods and kits., Results and Discussion: The in vivo antisalmonellal study revealed that this extract significantly (P<0.05) reduced the number of viable Salmonella Typhimurium recovered from faeces, and could stop salmonellosis after 10 days of treatment for male and female rats, with non-toxic doses. However, the biochemical and histological analyses revealed that at relatively high-doses (≥100mg/kg for females and 200mg/kg for males) the extract could induce liver damage, as illustrated by a rise of serum transaminases (ALT and AST), significant inflammation of the parenchyma and portal vein, as well as cell necrosis. There were also increases in cholesterol levels in both sexes. No significant unwanted side effect of the extract was observed on the kidney, as shown by both serum and urinary creatinine, and urinary protein levels., Conclusion: The results obtained showed that H. madagascariensis has a promising antisalmonellal effect and, therefore, the potential to provide an effective treatment against salmonellosis, including typhoid fever., (Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.)
- Published
- 2016
- Full Text
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45. Relationship between multiple drug resistance and biofilm formation in Staphylococcus aureus isolated from medical and non-medical personnel in Yaounde, Cameroon.
- Author
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Eyoh AB, Toukam M, Atashili J, Fokunang C, Gonsu H, Lyonga EE, Mandi H, Ikomey G, Mukwele B, Mesembe M, and Assoumou MC
- Subjects
- Cameroon, Female, Health Personnel, Humans, Male, Staphylococcus aureus isolation & purification, Biofilms, Drug Resistance, Multiple, Bacterial, Staphylococcus aureus drug effects, Staphylococcus aureus physiology
- Abstract
Introduction: Monitoring the prevalence of nasal carriage of multiple drug resistance (MDR) Staphylococcus aureus (SA) strains in hospital personnel is essential. These strains when transmitted from hospital personnel to patients with already weakened immune states or in-built medical devices, may limit the latter's treatment options. This study aimed at assessing the potential exposure of patients to these MDR SA in a resource-limited hospital setting by assessing the prevalence and relationship between antimicrobial susceptibility and biofilm forming capacity of SA isolates from hospital personnel., Methods: A total of 59 bacteria isolates phenotypically identified as Staphylococcus aureus obtained from medical (39) and non-medical personnel (20) in Yaounde were used in the study. Multiple drug resistance defined as resistance to four or more of twelve locally used antibiotics were determined by Kirby Bauer disc diffusion technique whereas quantification of biofilm production was by the microtitre plate method., Results: Among the 59 SA isolates, the prevalence of MDR was 50.9%. Among medical personnel 48.7% had MDR as against 55.9% for non-medical personnel (p-value=0.648). The overall percentage of weak biofilm producers was 35.6%. Although the prevalence of weak biofilm formers was higher in isolates from non-medical personnel (40%) than medical personnel (33.3%) the difference was not statistically significant (p-value= 0.246). Slightly less than half (42.9%) of the weak biofilm producers were MDR., Conclusion: Considering the high rates of MDR and that slightly less than half of biofilm formers were MDR, these trends need to be monitored regularly among hospital personnel in Yaounde.
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- 2014
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46. Traditional medicine: past, present and future research and development prospects and integration in the National Health System of Cameroon.
- Author
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Fokunang CN, Ndikum V, Tabi OY, Jiofack RB, Ngameni B, Guedje NM, Tembe-Fokunang EA, Tomkins P, Barkwan S, Kechia F, Asongalem E, Ngoupayou J, Torimiro NJ, Gonsu KH, Sielinou V, Ngadjui BT, Angwafor F 3rd, Nkongmeneck A, Abena OM, Ngogang J, Asonganyi T, Colizzi V, Lohoue J, and Kamsu-Kom
- Subjects
- Cameroon, Culture, Forecasting, Humans, National Health Programs organization & administration, Research trends, Socioeconomic Factors, Delivery of Health Care organization & administration, Medicine, African Traditional statistics & numerical data, Medicine, African Traditional trends, Plants, Medicinal
- Abstract
Traditional medicine refers to health practices, approaches, knowledge and beliefs incorporating plant, animal and mineral based medicines, spiritual therapies, manual techniques and exercises, applied singularly or in combination to treat, diagnose and prevent illnesses or maintain well-being. In the last decade traditional medicine has become very popular in Cameroon, partly due to the long unsustainable economic situation in the country. The high cost of drugs and increase in drug resistance to common diseases like malaria, bacteria infections and other sexually transmitted diseases has caused the therapeutic approach to alternative traditional medicine as an option for concerted search for new chemical entities (NCE). The World Health Organisation (WHO) in collaboration with the Cameroon Government has put in place a strategic platform for the practice and development of TM in Cameroon. This platform aims at harmonizing the traditional medicine practice in the country, create a synergy between TM and modern medicine and to institutionalize a more harmonized integrated TM practices by the year 2012 in Cameroon. An overview of the practice of TM past, present and future perspectives that underpins the role in sustainable poverty alleviation has been discussed. This study gives an insight into the strategic plan and road map set up by the Government of Cameroon for the organisational framework and research platform for the practice and development of TM, and the global partnership involving the management of TM in the country.
- Published
- 2011
- Full Text
- View/download PDF
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