1.Molecular characterization of mycotoxin-producing Aspergillus parasiticus and sensitivity pattern to different disinfectants
Zunira Mughis ; Muhammad Asad Ali ; Aftab Ahmad Anjum ; Muhammad Ovais Omer ; Mateen Abbas ; Maria Najeeb
Malaysian Journal of Microbiology 2022;18(5):524-532
Aims:
The study was aimed to isolate and characterize the mycotoxin-producing filamentous Aspergillus parasiticus from the feed samples. The sensitivity pattern of the isolates was assessed against different disinfectants.
Methodology and results:
Fifty different feed samples were screened for A. parasiticus isolation. Isolates were subjected to macroscopic and microscopic characterization. Polymerase chain reaction was performed to confirm the isolates at the genomic level. Mycotoxin producing potential of the isolates was assessed by thin-layer chromatography (TLC). To quantify the toxins, high performance liquid (HPLC) was employed. The antifungal potential of disinfectants was determined by the well diffusion method followed by minimum inhibitory concentration (MIC) calculation. Out of twenty isolates of A. parasiticus, 11(55%) isolates were observed positive for toxin production. Three toxigenic isolates (AspP2, AspP4 and AspP8) were selected to evaluate their susceptibility against disinfectants by well diffusion method. AspP2 produced maximum (5.90 ng/mL) toxin, followed by AspP4 (3.11 ng/mL) and AspP8 (18.47 ng/mL). Terralin showed maximum fungicidal activity with 29.66 ± 8.08 mm zone of inhibition at 0.42 μg/mL MIC. Hypochlorite and Instru Star showed 99% disinfection with 30, 60 and 90 min contact time (6 mean log reduction) for all A. parasiticus isolates. Alpha Guard inhibited growth after 15 min contact time for all the isolates.
Conclusion, significance and impact of study
This study provides data indicating the contamination of feed samples with mycotoxin-producing A. parasiticus isolates and their sensitivity against commercially available disinfectants. Use of these disinfectants in appropriate concentrations and time could help prevent the contamination of food, feed and healthcare settings with the fungal species.
Mycotoxins
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Aspergillus
2. Phytochemical analysis of Berberis lyceum methanolic extract and its antiviral activity through the restoration of MAPK signaling pathway modulated by HCV NS5A
Koloko Brice LANDRY ; Shafiq AZAM ; Somayya TARIQ ; Bushra IQBAL ; Bushra IJAZ ; Sidra REHMAN ; Mateen ABBAS ; Dieudonné Massoma LEMBÈ
Asian Pacific Journal of Tropical Biomedicine 2021;11(3):132-140
Objective: To evaluate the antiviral activity and phytochemicals of selected plant extracts and their effect on the mitogen-activated protein kinase (MAPK) signaling pathway modulated by hepatitis C virus (HCV) nonstructural protein 5A (NS5A). Methods: A total of ten plant extracts were initially screened for their toxicities against HepG2 cells. The non-toxic plants were tested for their inhibitory effect on the expression of HCV NS5A at both mRNA and protein levels using real-time PCR and Western blotting assays, respectively. The differential expression of the genes associated with MAPK pathway in the presence of NS5A gene and plant extract was measured through real-time PCR. Subsequently, the identification of secondary metabolites was carried out by phytochemical and HPLC analysis. Results: The phytochemical profiling of Berberis lyceum revealed the presence of alkaloids, phenols, saponins, tannins, flavonoids, carbohydrates, terpenoids, steroids, and glycosides. Similarly, quercetin, myricetin, gallic acid, caffeic acid, and ferulic acid were identified through HPLC analysis. The methanolic extract of Berberis lyceum strongly inhibited HCV RNA replication with an IC50 of 11.44 μg/mL. RT-PCR and Western blotting assays showed that the extract reduced the expression of HCV NS5A in a dosedependent manner. Berberis lyceum extract also attenuated NS5Ainduced dysregulation of the MAPK signaling pathway. Conclusions: Our findings suggest that Berberis lyceum extract strongly inhibits HCV propagation by reducing HCV NS5Ainduced perturbation of MAPK signaling.