Aspergillus fumigatus
is the most reported causative pathogen associated with the increasing global incidences of aspergilloses, with the health of immunocompromised individuals mostly at risk. Monitoring the pathogenicity of
A. fumigatus
strains to identify virulence factors and evaluating the efficacy of potent active agents against this fungus in animal models are indispensable in current research effort.
Caenorhabditis elegans
has been successfully utilized as an infection model for bacterial and dimorphic fungal pathogens because of the advantages of being time-efficient, and less costly. However, application of this model to the filamentous fungus
A. fumigatus
is less investigated. In this study, we developed and optimized a stable and reliable
C. elegans
model for
A. fumigatus
infection, and demonstrated the infection process with a fluorescent strain. Virulence results of several mutant strains in our nematode model demonstrated high consistency with the already reported pathogenicity pattern in other models. Furthermore, this
C. elegans-A. fumigatus
infection model was optimized for evaluating the efficacy of current antifungal drugs. Interestingly, the azole drugs in nematode model prevented conidial germination to a higher extent than amphotericin B. Overall, our established
C. elegans
infection model for
A. fumigatus
has potential applications in pathogenicity evaluation, antifungal agents screening, drug efficacy evaluation as well as host-pathogen interaction studies.
Aspergillus flavus is one of the important human and plant pathogens causing not only invasive aspergillosis in immunocompromised patients but also crop contamination resulting from carcinogenic aflatoxins (AFs). Investigation of the targeting factors that are involved in pathogenicity is of unmet need to dismiss the hazard. Phosphoglucose isomerase (PGI) catalyzes the reversible conversion between glucose-6-phosphate and fructose-6-phosphate, thus acting as a key node for glycolysis, pentose phosphate pathway, and cell wall biosynthesis in fungi. In this study, we constructed an A. flavus pgi deletion mutant, which exhibited specific carbon requirement for survival, reduced conidiation, and slowed germination even under optimal experimental conditions. The Δpgi mutant lost the ability to form sclerotium and displayed hypersusceptibility to osmotic, oxidative, and temperature stresses. Furthermore, significant attenuated virulence of the Δpgi mutant was documented in the Caenorhabditis elegans infection model, Galleria mellonella larval model, and crop seeds. Our results indicate that PGI in A. flavus is a key enzyme in maintaining sugar homeostasis, stress response, and pathogenicity of A. flavus. Therefore, PGI is a potential target for controlling infection and AF contamination caused by A. flavus.
Aspergillus fumigatus
is an opportunistic fungal pathogen causing deadly infections in immunocompromised patients. Enzymes essential for fungal survival and cell wall biosynthesis are considered potential drug targets against
A. fumigatus
.
The threat burden from pathogenic fungi is universal and increasing with alarming high mortality and morbidity rates from invasive fungal infections. Understanding the virulence factors of these fungi, screening effective antifungal agents and exploring appropriate treatment approaches in in vivo modeling organisms are vital research projects for controlling mycoses. Caenorhabditis elegans has been proven to be a valuable tool in studies of most clinically relevant dimorphic fungi, helping to identify a number of virulence factors and immune-regulators and screen effective antifungal agents without cytotoxic effects. However, little has been achieved and reported with regard to pathogenic filamentous fungi (molds) in the nematode model. In this review, we have summarized the enormous breakthrough of applying a C. elegans infection model for dimorphic fungi studies and the very few reports for filamentous fungi. We have also identified and discussed the challenges in C. elegans-mold modeling applications as well as the possible approaches to conquer these challenges from our practical knowledge in C. elegans-Aspergillus fumigatus model.
With the mortality rate of invasive aspergillosis caused by Aspergillus fumigatus reaching almost 100% among some groups of patients, and with the rapidly increasing resistance of A. fumigatus to available antifungal drugs, new antifungal agents have never been more desirable than now. Numerous bioactive compounds were isolated and characterized from marine resources. However, only a few exhibited a potent activity against A. fumigatus when compared to the multitude that did against some other pathogens. Here, we review the marine bioactive compounds that display a bioactivity against A. fumigatus. The challenges hampering the discovery of antifungal agents from this rich habitat are also critically analyzed. Further, we propose strategies that could speed up an efficient discovery and broaden the dimensions of screening in order to obtain promising in vivo antifungal agents with new modes of action.
University students occupy a strategic position in the spread of coronavirus disease 19 (COVID-19) as they regularly travel around different locations with differing prevalence of the disease. This study was carried out to evaluate the acceptance of COVID-19 vaccines among university staffs and students in Southeastern universities of Nigeria. Self-administered anonymous online survey was conducted between 28th February and 30th June 2021, using various online social media handles. A total of 769 students and staff members participated in the study. Descriptive statistics for socio-demographics and other parameters were performed. The relationships between tested parameters were ascertained using bivariate Pearson’s correlation. Multiple linear regression analyses were done to determine associations. All statistical analyses were performed using IBM SPSS statistics 23 and P value < 0.05 was considered statistically significant at 95% CI. The respondents were 48.1% female and 51.9% male with a mean age of 24.4 years. The acceptance rate of COVID-19 vaccine was 25.6% and 82.2% of participants expressed concern about the side effects of the vaccine. While the age, gender and states of respondents were positively associated, their faculties were negatively associated with risk perception of COVID-19 vaccine. Also, the various faculties, university affiliations (P = 0.029), and age (P = 0.023) of the respondents were negatively associated, while the State of the respondents (P = 0.01) was positively associated with attitudes towards general COVID-19 vaccination. There is need for more robust information and better dissemination of such among the public to boost their confidence in COVID-19 vaccination.
The abilities of three species of freshwater microalgae to grow in, and desalinate untreated and undiluted seawater were investigated. The salinities of the seawater were reduced from 37.5g/L to 26.25 ± 1.33, 27.19 ± 1.33 and 30.0 ± 0.00 g/L by Desmodesmus subspicatus LC172266, Desmodesmus armatus LC172263 and Dictyosphaerium spp. LC172264 on the fourth, eighth and tenth week of the experiment, respectively, while the control had no change in the salinity. D. subspicatus cell concentration initially dropped from 1.25 × 106 cells/ml to 9.68 × 105 cells/ml and then gradually increased to 4.86 × 107 cells/ml by the tenth week. With D. armatus and Dictyosphaerium spp., the cell concentrations increased steadily from 1.25 × 106 cells/ml to 4.97 × 108 cells/ml and 3.25 × 108 cells/ml, respectively. There were increases in the pH during desalination by the three species. This demonstrates the halotolerant potentials of these species and their abilities to reduce the salinity of seawater.
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