Nkenfou, C. N. | Search bioRxiv

bioRxiv2026

Genetic Diversity and Antifungal Susceptibility among Ecological Niche Populations of Aspergillus flavus in Yaounde, Cameroon

Aspergillus flavus is a ubiquitous fungus commonly found in a variety of ecological niches including soil, crops, the air, and humans. In humans, it is the second leading cause of invasive aspergillosis (IA) and is linked to other illnesses through contamination of agricultural products with aflatoxins. As such, A. flavus threatens food safety, economic wellbeing, and human health, particularly in less developed regions and countries such as Cameroon. To mitigate these effects, farmers and clinicians rely on triazoles to reduce aflatoxin contamination and treat IA. However, a consequence of increasing triazole use is the emergence and spread of triazole resistance in both agriculture and clinics. To identify the prevalence of triazole resistance and the potential relationships among triazole resistant and susceptible strains, this study investigated antifungal susceptibility to both clinical and agricultural triazoles and analyzed genetic variation among various ecological niche populations of A. flavus in Cameroon. Strain genotypes were obtained through analysis of six polymorphic microsatellite markers. Our analyses revealed that 30.3% (17/56) of the strains were resistant to at least one of the four triazoles, with increased minimum inhibitory concentrations found among crop-isolated strains. A Permutational Multivariate Analysis of Variance suggested limited ecological niche-based clustering of genotypes, consistent with frequent gene flow and dispersal among ecological niches. A multilocus linkage disequilibrium analysis revealed evidence of non-random recombination in A. flavus. Overall, this study elucidates the interplay between ecological pressures, antifungal resistance, and genetic differentiation, and invites alternative methods to control aflatoxin contamination in foods without the use of agricultural fungicides.

microbiology↗

bioRxiv2018

Factors Associated with Risk Of HIV-Infection Among Pregnant Women in Cameroon: Evidence from the 2016 National Sentinel Surveillance Survey of HIV and syphilis

BackgroundHuman Immunodeficiency Virus infection (HIV) remains a public health concern in Cameroon that requires regular surveillance for informed policy-making to guide programmatic interventions. Using data from the 2016 HIV national sentinel survey in Cameroon, we ascertained HIV prevalence and factors associated with risk of infection among pregnant women\n\nMethodsA cross-sectional study was conducted throughout 2016 in the 10 regions of Cameroon, targeting 7000 first antenatal care (ANC-1) attendees (4000 from urban and 3000 from rural areas) in 60 sentinel health facilities. HIV serological test was performed using the national serial algorithm at the National Reference Laboratory (NRL). Prevalence was determined, and multivariate logistic regression was used to assess determinants of HIV infection, with p-value<0.05 considered statistically significant.\n\nResultsOf the 7000 targeted participants, a total of 6859 first ANC-1 attendees were enrolled (98.0% sampling coverage). Median age was 26 [IQR: 21-30] years and 47,40% had a secondary school level of education. The national prevalence of HIV was 5.70% (95% CI: 4.93 - 6.40) and range from 9.7% in East region to 2.6% in North region. The prevalence was 5.58% (95% CI: 95%: 4.88 - 6.35) in urban and 5.87% (95% CI: 5.04 - 6.78) in rural settings. Factors that were associated with HIV infection included marital status, women who were married or living with their partner are less likely to be infected than singles women (aOR=0.60; 95% CI: 0.46 - 0.78), multiparity [aOR=1.5(95%CI:1.0-2.2)] and been living in the Centre, East, North-west and South-west regions. HIV infection was also significantly associated with age, with the risk of being infected increasing with age.\n\nConclusionPregnant women in Cameroon are still disproportionately infected with HIV compared with the general population (prevalence 4.3%). Preventive actions to curb the epidemic amongst pregnant women should prioritize interventions targeting single pregnant women, who are older, and residing particularly in the Centre, East, North West and South West regions of the country.

epidemiology↗