Ahmed, Risikat Nike
@unilorin.edu.ng
Associate Professor/ Department of Microbiology.
University of Ilorin,Ilorin
RESEARCH, TEACHING, or OTHER INTERESTS
Applied Microbiology and Biotechnology, Microbiology, Molecular Biology, Sensory Systems
Scopus Publications
Scholar Citations
Scholar h-index
Scholar i10-index
Scopus Publications
Risikat Nike Ahmed, Mercy Oluwaseyi Bamigboye, Kamoldeen Abiodun Ajijolakewu, Sheriffdeen Olakunle Idris, and Nimat Toyosi Ajide Bamigboye
Univ. of Malaya
Antibiotics are one of the most exploited metabolites produced by soil actinomycetes. This study isolated fifteen actinomycetes (A1 – A15) from dumpsite soils within Ilorin metropolis & screened them for antibacterial activity. Isolates were identified with morphology & biochemical characteristics.Their activity against clinical bacteria (Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae & Staphylococcus aureus) was determined. Their bioactive metabolites after fermentation was assayed for by agar well diffusion & compared with reference antibiotics. Molecular analysis of two most active isolates was done. The most active metabolite was subjected to GCMS. All isolates were identified as Streptomyces, 7 isolates exhibited activity against 3 test bacteria with highest (10.5mm±0.35) by Streptomyces griseoplanus while S. aureus demonstrated total resistance to all isolates. Secondary activity revealed 7 of the metabolites as effective against the bacteria with highest activity (28.5±1.04mm) by S. sparsogenes showing similar activity with Cefuroxime (28.01±0.01mm). The two most active isolates were Streptomyces griseoplanus strain NR725RL-ISP 5009 & Streptomyces sparsogenes strain NBRC 1308616S & RNA nucleotide similarity revealed close phylogenic relationship. GC-MS revealed10 compounds in S. sparsogenes strain NBRC 1308616S metabolite. Streptomyces from dumpsite soils within Ilorin produced bioactive compounds against clinical test bacteria and thus could be potential sources of antibiotics.
M. A. Balogun, R. N. Ahmed, O. A. Akintayo, T. E. Aruna, M. O. Omovbude, and T. Shittu
Sri Lanka Journals Online (JOL)
Pigeon pea (Cajanus cajan L.) is an important grain legume crop predominantly grown in India. Changes in the microbial and chemical qualities of pigeon pea during wild (96 h) and controlled (72 h) fermentations were investigated. Sensory properties of the resulting condiments were also evaluated. Organisms associated with 96 h wild fermentation of pigeon pea included Bacillus species, Lactobacillus species, Staphylococcus aureus, Escherichia coli, Escherichia faecalis and Pseudomonas aeruginosa. pH decreased with wild (from 7.5 to 5.0) and controlled (from 7.4 to 6.0) fermentations. There was a steady decrease in crude fibre, crude fat and carbohydrate but an increase in ash, moisture and crude protein with increasing length of fermentation periods. Phytate, oxalate, tannins, and trypsin inhibitory activity of fermented condiment decreased with increasing fermentation period. Sensory evaluation showed that pigeon pea produced from controlled fermentation had higher scores in colour and texture compared with commercial condiment (iru). This study has revealed the feasibility of producing pigeon pea condiment using wild and controlled fermentation, and this presents a veritable strategy to increase the utilization of the crop.
AHMED Risikat Nike, DANIEL Folake, GBALA Ifeoluwa Deborah, and SANNI Alhassan
African Journals Online (AJOL)
BACKGROUND: Increased antibiotic resistant properties of pathogens has led to a pronounced search for new effective antibiotics from microbes in diverse ecological niches. This study focused on isolating actinomycetes from soil of reserved areas and profiling them for antibacterial potentials.METHODS: The isolates (IS-2, IS-4, IS-6, IS-10, IS-14) were assessed for antagonistic activity against ten multi-drug resistant bacterial strains (Gram positive and negative) by cross streak and well diffusion methods.RESULTS: During the primary screening, four of the isolates showed good antagonistic activity against the test strains. Notably, all the bacterial strains except Pseudomonas aeruginosa responded sensitively to at least one of the actinomycetes screened. The crude extracts of the secondary metabolites of the four actinomycetes (IS-2, IS-4, IS-6, IS-10) with considerably significant antagonistic activities inhibited the growth of all the bacterial strains efficiently. All the test bacterial strains were sensitive to at least one of the extracts at a concentration of 100μg/ml. The minimum inhibitory concentration of the extracts against the isolates ranged from 12.5 - 25μg/ml. The crude extracts of IS-4 and IS-6 identified as Streptomyces glauciniger NBRC 100913 and Streptomyces griseoplanus NRRL-ISP 5009 by I6s rRNA sequencing, showed higher antibacterial activities against the bacterial strains. Significantly, the ethyl acetate crude extract of the actinomycetes demonstrated better antibacterial activities than the standard antibiotics (ofloxacin, amoxicillin/clavulanate, cefuroxime and ceftriaxone).CONCLUSION: This study reports remarkable anti-MRSA activities as well as broad spectrum antibacterial potentials of extracts of Streptomyces spp. worthy of further exploration.
Risikat N. AHMED, Sesan M. SOBA, Mercy O. BAMIGBOYE, and Kamoldeen A. AJIJOLAKEWU
Society of Land Measurements and Cadastre from Transylvania
The present research aimed at screening various soils within Ilorin metropolis for antibiotic producing actinomycetes. The objectives of the study were to determine physiochemical parameters of soils, the occurrence of actinomycetes in soils, antibacterial potentials and identity of isolates. Soil parameters such as pH, temperature, moisture, organic matter and soil type were evaluated following standard procedures. Selective isolation to determine the occurrence of actinomycetes was performed by soil dilution using pour plate technique on starch casein agar. Preliminary antibacterial screening against 10 clinical test bacteria was performed using cross streak method. All isolates were initially identified based on morphological and biochemical characteristics, while the most bioactive isolates were further identified by molecular means. The soils were alkaline, with temperatures between 29 °C and 31 °C, moisture was in range of 0.72 ± 0.07c and 6.62 ± 0.42b. Highest organic matter content was 32.13 ± 0.20a with soil types mostly loamy and sandy loam. Ten actinomycetes (SM1 - SM10) were isolated, with the most frequently occurring isolate being SM3 and SM5 (16.7%). SM5 was the most active, inhibiting 9 out of 10 tests, with the highest inhibition against Staphylococcus aureus 25923 (24 mm ± 0.15a). All isolates were identified as Streptomyces by morphology and biochemical tests. Based on nucleotide similarity searches and phylogeny, two bioactive Streptomycetes were suggested as novel strains and thus named as Streptomyces bottropensis UIL RNA (SM5) and S. flavoviridis UIL RNA(SM7), which may serve as promising sources of antibiotics. Actinomycetes from Ilorin metropolis demonstrated broad spectrum of antibacterial activity against clinical test bacteria.
Rotimi Olusanya Arise, Jalil James Idi, Iseoluwa Maureen Mic-Braimoh, Emmanuel Korode, Risikat Nike Ahmed, and Omorefosa Osemwegie
Elsevier BV
Risikat Nike Ahmed, Bamigboye Oluwaseyi Mercy, and Sheriffdeen Olakunle Idris
University of Baghdad College of Science
Three beach soils in Lagos, Nigeria were screened for the presence of antibiotic producing fungi against 8 test pathogenic bacteria & fungi. The physiochemical parameters of the soils were determined following standard procedures. Soil plate dilution method was employed for isolation of marine fungi and they were identified based on cultural and microscopic characteristics. Primary screening of isolated fungi for antibiotic potential was determined by perpendicular streak method against known pathogenic test organisms (Escherichia coli, Saphylococcus aureus, Klebsiella pnuemoniae, Pseudomonas aeruginosa, Candida albicans, Saccharomyces cerevisiae,Aspergillus niger and Aspergillus fumigatus). Further sreening of the product of secondary metabolism [antibiotic] of the active fungi was done by agar disc diffusion assay. The fungus with the highest secondary activity was subjected to molecular analysis for further identification. pH of beach soils was alkaline ranging from 7.6-8.0, while temperature and moisture were normal ranging from 26.333 ± 1.155a-30.333 ± 0.577aand 7.142 ± 1.497a-10.030 ± 3.130a respectively. A total of four fungal species of 2 different genera were isolated from the beaches ;Aspergillus niger,Aspergillus flavus,Penicillium purpurogenum and Penicillium islandicum. Both primary and secondary assays revealed only antibacterial activities against Staphylococcus aureus and Psedomonas aeruginosa with no effect on all test fungi. Highest antibacterial activity[28+0.2a] was exhibited by the fungus identified as Penicillium purpurogenum. Fungi from beaches in Lagos, Nigeria may be a promising source of antibacterial agent useful in the treatment of infections caused by S. aureus and P. aeruginosa.
S.A. Bolu, T.O. Babalola, N. Elelu, R.N. Ahmed, S.A. Oyetunde, P.F. Ademola, and S.A. Jiddah
Diva Enterprises Private Limited
A 6-weeks feeding trial was carried out to elucidate the effect of different levels of aloe vera leaf extract on the performance and health of turkey poults challenged with Escherichia coli. Sixty (60) turkey poults were randomly grouped into five treatments which were further replicated three times in a completely randomized design. The first group of poults was without infection and fed on the basal diet alone, and served as the positive control (P-CON). Out of the rest four infected groups, one was fed the basal diet alone to serve as the negative control (N-CON), while the others were fed the basal diet with tetramycin (ANT), or aloe vera at 2-mL (ALV2) and 3-mL (ALV3) per litre of water. The response of turkey poults to the challenge were assessed in terms of their growth performance, histology, haematology and serum constituents. The growth parameters, such as survival, weight gain, feed conversion efficiency were significantly (P<0.05) higher in poults given ALV3. Histological results of the organs (breast muscle, liver, spleen and ileum) showed normal morphological pattern for poults subjected to ALV2 while those kept on ALV3 showed normal for breast muscle, spleen and ileum but not for the liver. Similarly, birds raised on ANT showed normal organ morphology compared with the positive control. However, the birds challenged with E. coli without (N-CON) showed abnormal morphological pattern for all the organs investigated. There were also no adverse effects of aloe vera leaf extract on turkey poults health, as determined from the analysis of various haematological parameters and serum metabolites. The results indicated that Aloe vera leaf extract inclusion at 2mL (ALV2) in drinking water could successfully replace antibiotics in the rearing of turkey poults.
Alafara A. BABA, Folahan A. ADEKOLA, Rasaq F. ATATA, Risikat N. AHMED, and Sandeep PANDA
Elsevier BV
Atata, F R, Ibrahim, K E Akanbi Y, A A, Abdul, F I, Sani, A, Ahmed,et al.
Academic Journals
Microbiological quality of some brands of intravenous fluids produced by some pharmaceutical companies in Nigeria was investigated. Membrane filtration method was used for concentration of contaminating organisms in the intravenous fluids. Thioglycollate medium, Tryptone Soya broth, Brilliant Green Agar, Pseudomonas medium, Mannitol salt agar, MacConkey agar, and Nutrient agar and Saboraud dextrose agar were the media used for the isolation and differentiation of the microbial species. Rabbitory method was used for Pyrogen test. Out of 160 samples analyzed, 14 (8.25%) were contaminated and remaining 146 (91.75%) were found sterile. The result of pyrogen test showed that 58 (36.25%) of the samples were pyrogenic. Dextrose (5%), peritoneal dialysis and Normal saline were free of detectable microbial species. Contaminating organisms in Dextrose Saline are Microsporum fulvum and Aspergillus sp. In Half strength Darrow’s Bacillus cereus, Klebsiella pneumoniae and Aspergillus sp. were detected. In Half strength Darrow’s, Full strength Darrow’s and Ringer Lactate, the contaminating bacterial species include K. pneumoniae, M. fulvum, Aspergillus sp. and Penicillium sp.