Browsing by Author "Aliyu Abdulmalik"

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    Antimicrobial Peptide Design, Molecular Docking and ADMET Studies Against the Methicillin-Resistant Staphylococcus aureus and Carbapenem resistant and Carbapenemase-producing Pseudomonas aeruginosa
    (Trends in Peptide and Peptide Sciences, 2022-10) Aliyu Abdulmalik
    Carbapenem-resistant and carbapenemase-producing Pseudomonas aeruginosa (CRPA) and methicillin-resistant Staphylococcus aureus (MRSA) are two pathogens that are resistant to currently available antimicrobials. As an alternative to effective medication molecules, antimicrobial peptides (AMPs) have the potential to cure superbug-caused infections effectively. Two new AMPs (ama1 and ama2) were designed utilizing a knowledge-based technique with optimal parameters. First, the PEP-FOLD 3.5 server made a de novo prediction of the AMPs' three-dimensional (3D) structure, which was validated using PROCHECK of SAVES v6.0 by checking the amino acid locations in the Ramachandra plot. Then, protein-peptide docking simulations of the predicted AMPs and reference AMP (Aurein 1.2) for positive control were performed using the HPEPDOCK docking web server, followed by the computation of the AMPs' physicochemical parameters and toxicity profile using the ProtParam and vNN-ADMET web servers, respectively. The sequences for ama1 and ama2 were AWGKIKALR and IKWLRLAKP, respectively. Docking analysis revealed that the antibacterial activity of ama1 and ama2 was superior to that of Aurein 1.2 against CRPA-resistant enzyme (6ew3), respectively. However, ama1, ama2, and Aurein 1.2 inhibited the activity of MRSA-resistant protein (4c12). Both the physicochemical qualities and the toxicity profiles were advantageous. Therefore, the in-silico-derived AMPs could serve as a pharmaceutical candidate for developing multidrug-resistant bacteria-effective antimicrobials.
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    Characterization of Some Novel Antimicrobial Peptides from African Common Toad, Sclerophrys regularis
    (African Journal Online, 2021) Aliyu Abdulmalik; Y.K.E. Ibrahim; B.A. Tytler
    The growing number of antimicrobial resistant bacteria have necessitated urgent need for newer and effective antimicrobials. Antimicrobial peptides (AMPs) which are also called host defense peptides are promising class of bioactives found in all living thing especially amphibians. A total of 355 Sclerophrys regularis were collected and each toad was weighed and 0.02mL/g of epinephrine (1mg/mL) was administered via the dorsal lymph sac of the toad. The skin secretions were washed, lyophilized and stored at -20°C. The secretion was purified using Sephadex G-50 gel purification column. The fractions showing antimicrobial activities against Pseudomonas aeruginosa ATCC 27853, Escherichia coli ATCC 25922, Salmonella typhii ATCC 14028, Citrobacter freundii ATCC 8090, Staphylococcus aureus ATCC 25913 and Candida albicans ATCC 3147 were further purified by RP- HPFC. The purified fractions were lyophilized and m/z ratio peaks were determined using MALDI TOF/TOF MS. The sequences corresponding to the peaks were determined using Mascot Peptide Mass Fingerprint which revealed novel AMP sequences: IHAGKTVPIVK, MHLLWR and LTGQIKNGLSGR which were named Regularin-2, Regularin-3 and Regularin-4 respectively. The MICs of purified fractions were between 50 – 200 µg/mL and the antimicrobial activities were maintained when stored at -20 °C for 180 days and was significant at p < 0.05. Bioprospecting of Nigerian toad specie (S. regularis) could yield potential therapeutic AMP agents.
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    Phenotypic Characterization and Resistance Trends of Klebsiella pneumoniae from Selected Hospitals in Ilorin, Kwara State Nigeria
    (FACULTY OF SCIENCE, FEDERAL UNIVERSITY GUSAU, NIGERIA, 2025-07-26) Aliyu Abdulmalik; David, Susan M.; Bello, Ronke H.; Olufadi-Ahmed, Haisat Y.; Sani, Muhammed A.; Akinpelu, Lateef A.; Abdussalam, Ummkhair O.; Mamman, Oyinnoiza; Gbade, Oluwapelumi M.; Salman, Islamiyat O.; Naibi Mohammed; Shittu, Abiodun O.; Njinga, Ngaistad S.
    Klebsiella pneumoniae has emerged as a formidable pathogen, complicating the treatment of infections in healthcare settings. In this study, we examined the phenotypic characteristics and resistance trends of K. pneumoniae isolates from 150 clinical samples - including urine, blood, and deep throat sputum - collected from selected hospitals in Ilorin, Nigeria. Forty-nine isolates were recovered, with a predominance among female patients and individuals aged 18 - 40 years. Identification and antimicrobial susceptibility testing were performed using standard bacteriological methods and a modified Kirby-Bauer disc diffusion technique. The findings revealed a concerning level of resistance to cephalosporins and beta-lactam/β-lactamase inhibitor combinations, whereas aminoglycosides, carbapenems, and fluoroquinolones demonstrated relatively higher susceptibility rates. Notably, the majority of the isolates exhibited multidrug resistance, with several showing high Multiple Antibiotic Resistance Index values that underscore the significant antibiotic pressure in the clinical environment. These results highlight the urgent need for enhanced antibiotic stewardship and continuous surveillance to inform targeted treatment strategies. The insights gained from this study provide crucial data for developing effective interventions aimed at curbing the spread of multidrug-resistant K. pneumoniae and ultimately improving patient outcomes in resource-limited settings.