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- ItemMicrobiology Laboratory Workshop(KWASU PRESS, 2024-05-01) Authors: Prof. S. Awe; Prof. A.E. Ajiboye; Prof. M.R. Adedayo; Dr. A.T. Ajao; Dr. W.T. Aborisade; Dr. F.A. Jimoh; Dr. Z.B. Abdulsalam; Dr. S.A. Abdulmumini; Dr. B.O. Yusuf-Salihu; Mr. M.M. Abdulrazaq; Mrs. A.O. Amupitan; Mrs. L. Uthman-Saheed; Mr.A . Muhammad; Mrs.R.O.Said; Mr.A.O.Ahmed; Mrs D.O. Gabriel; Mrs. H.A. Mohammed; Mrs. G.B. Yusuf; Mr. S.S. Jumah
- ItemBacteraemia in a Nigerian hospital: Implementing antimicrobial resistance surveillance(Journal of Public Health in Africa, 2025-02-07)Background: Surveillance of drug-resistant infections is crucial for antimicrobial resistance (AMR) control. Implementing surveillance in low- and middle-income countries (LMICs) is challenging. Aim: To investigate bacteraemia and describe AMR surveillance. Setting: Tertiary healthcare facility. Methods: Case finding was by WHO Global AMR and Use Surveillance System (GLASS). Blood samples were processed between May 2017 and June 2018, using BACTEC blood culture system. Bacterial identification, antibiotic susceptibility testing and detection of AMR genes followed standard protocols. Results: Aerobic blood cultures were conducted in a third of clinical sepsis cases (n = 601/1851), of which 114 (19.0%) were true positives, with a 2.2% contamination rate. Pathogens recovered included six priority blood pathogens reportable to WHO GLASS. Sixteen (30.2%) of 53 Gram-negative isolates were extended-spectrum beta-lactamase producers, predominantly harbouring blaCTX-M, three (5.7%) were AmpC beta-lactamase producers, and 20 (37.7%) were carbapenem-resistant, predominantly harbouring blaKPC . Twenty-nine (50.9%) of 57 Staphylococcus aureus isolates were methicillin-resistant; 17 (58.6%) of these harboured mecA genes. Hospital-acquired infection (odds ratio [OR] = 0.3, 95% confidence interval [CI]=0.1–0.7, p = 0.004) was identified as a predisposing factor for the development of multidrug-resistant (MDR) bacteraemia. Bacteraemia with MDR organisms was significantly associated with mortality (OR = 3.8, 95% CI = 1.6–9.1, p = 0.001). Conclusion: A wide variety of bacteria are responsible for bacteraemia in our setting, with more than half being multidrug-resistant. Bacteraemia with multidrug-resistant organisms was significantly associated with mortality, hence, the need for this AMR surveillance initiative. Contribution: Implementing healthcare facility-based surveillance of AMR in LMICs is achievable despite limited microbiological laboratory capacity. Keywords: bacteraemia; antimicrobial-resistance; surveillance; healthcare-facility; Nigeria; GLASS; multidrug resistance; implementation.
- ItemAntimicrobial Effects of Ocimum gratissimum Extracts on the Spoilage Organisms Isolated from Yoghurt Samples(UJMR, 2025-06-14) Amupitan Adefunke Olawumi; AjiboyeAdeyinka Elizabeth; Adedayo Majekodunmi Rachael; Amupitan Adewale AlexOcimum gratissimum (OG) is recognised for its nutritional, antioxidant, and antimicrobial properties, making it a strong candidate for natural food preservation. This study evaluated the effects of ethanolic and aqueous OG leaf extracts against spoilage organisms isolated from laboratory-prepared yoghurt samples stored at room temperature for ten days. The agar well diffusion technique was employed for antimicrobial screening, while the broth microdilution method was used to determine both minimum inhibitory concentration (MIC) and minimum cidal concentration (MCC). The isolated organisms included Bacillus subtilis, Bacillus spp., Saccharomyces cerevisiae, Saccharomyces bulderi, Pichia kudriavzevii, Aspergillus niger, and Aspergillus flavus, identified by standard microbiological methods. The aqueous extract at a concentration as low as 62.50 mg/mL inhibited Bacillus subtilis, Saccharomyces bulderi, Pichia kudriavzevii, and Saccharomyces cerevisiae, with inhibition zones ranging from 5.00±0.27 to 6.20±0.87 mm. The ethanolic extract exhibited antimicrobial effects against Bacillus subtilis, Bacillus spp., Saccharomyces bulderi, Pichia kudriavzevii, and Saccharomyces cerevisiae at the same concentration (62.50 mg/mL), but with larger inhibition zones ranging from 5.30±0.45 to 11.35±2.10 mm. The aqueous extract showed substantial inhibition of Bacillus subtilis, Saccharomyces bulderi, and Pichia kudriavzevii, with an MIC of 62.50 mg/mL. In contrast, the ethanolic extract demonstrated an MIC of 31. 25 mg/mL for Bacillus subtilis, Bacillus spp., and Aspergillus niger. The MCC of the aqueous extract was 250 mg/mL for Bacillus subtilis, Saccharomyces bulderi, Pichia kudriavzevii, Aspergillus flavus, and Saccharomyces cerevisiae, while the MCC of the ethanolic extract was 125 mg/mL for Bacillus subtilis and Bacillus spp. Overall, the OG extracts exhibited substantial antimicrobial effects, effectively inhibiting the growth of spoilage organisms isolated from stored yoghurt samples. Harnessing the potential of OG can lead to an extended shelf life for yoghurt, positioning OG as a promising natural preservative
- ItemBiodegradation of Total Petroleum Hydrocarbons and EPA-16 PAHs in Crude Oil by Pseudomonas aeruginosa KUD2(2025) Oluwabukola Kudirat Jimoh-Hamza and Abdullahi Taiwo AjaoThe complex mixture of hydrocarbons known as Speciated EPA-16 Polyaromatic Hydrocarbons (PAHs), which are frequently found in crude oil and are known to be extremely hazardous, mutagenic, carcinogenic, teratogenic, and immunotoxicogenic to different life forms, is included in the category of Extractable Total Petroleum Hydrocarbons (ETPHs), which also includes aliphatic compounds. Considering the environmental and public health hazards linked to ETPHs and PAHs, there is a compelling need to explore indigenous bacteria with the capability to efficiently degrade these contaminants. The present study investigated the biodegradation potential of bacterial isolates from oilpolluted soil, focusing on Extractable Total Petroleum Hydrocarbons (ETPHs) - Aliphatic and Speciated EPA-16 Poly Aromatic Hydrocarbons (PAHs) in crude oil samples. In this study, four predominant bacterial isolates, designated as KUD1, KUD2, KUD3, and KUD4, were isolated from oil-contaminated soil obtained from Okrika in Rivers State, Nigeria. These isolates exhibited positive outcomes in both the drop collapse and oil displacement tests, affirming their biosurfactant-producing, surface tension-reducing, and oil-displacing capabilities. Among them, KUD2 exhibited the highest emulsification index, highlighting its proficiency in forming stable oil-in-water emulsions. Consequently, KUD2, owing to its remarkable growth on agar plates containing 10% crude oil, was chosen for further investigation. The highly efficient isolate, KUD2 identified as Pseudomonas aeruginosa using 16S rDNA sequencing. The isolate exhibited enzymatic capabilities in the degradation of hydrocarbons, with catechol-1,2-dioxygenase enzymes detected with varying activity levels over time. Conversely, catechol-2,3-dioxygenase (C23O) remained consistently inactive throughout the experiment, suggesting alternative metabolic pathways or a lack of involvement in the studied biodegradation process. During the incubation period, the pH fluctuations correlated with the highest enzyme production, suggesting metabolic adaptations. Furthermore, P. aeruginosa KUD2 demonstrated significant increases in Alkane hydroxylase and Alcohol dehydrogenase secretion, reaching peak production after ten days of incubation signifying their active catalytic roles within the pathways associated with the investigated biodegradation process. Mass chromatograms revealed the presence of aromatic hydrocarbons in control crude oil samples, while KUD2 efficiently degraded ETPHs, reducing their concentration. Likewise, KUD2 demonstrated effective degradation of Speciated EPA-16 PAHs. The concentrations of aliphatic hydrocarbons in crude oil were significantly reduced after degradation, with some compounds being entirely degraded. Overall, this study underscores the potential of P. aeruginosa KUD2 for environmental bioremediation, as it efficiently degrades hydrocarbons and highlights the enzyme dynamics and pH influences in the biodegradation process.
- ItemBioremediation of soil contaminated with cassava mill effluents - A structural, functional, and metagenomics approach(ELSEVIER, 2025) A.T. Ajao, S. Awe, W.T. Aborisade, F.A. Jimoh, F.J. AjaoCassava mill effluent (CME) is a toxic pollutant that acidifies soil, accumulates cyanide and heavy metals, and drastically reduces soil fertility and microbial diversity. To address this, we evaluated the bioremediation po- tential of selected cyanide-degrading bacteria ( Pseudomonas fluorescens, Bacillus pumilus, Pseudomonas putida , and Pseudomonas stutzeri ) in CME-polluted soil using an integrated approach combining enzymatic assays, metage- nomic profiling, and molecular docking analyses. In laboratory microcosms, these strains significantly improved soil conditions over 20 days: soil pH increased from ∼4.8 to ∼7.4, cyanide levels fell by over 80 %, and key heavy metals (e.g., Cu2 + , Cd2 + ) were eliminated or sharply reduced. Heterotrophic bacterial counts rebounded, and enzymatic activity (nitrilase, cyanide dihydratase) correlated with the degradation of cyanide. Metagenomic sequencing revealed a restored and more diverse microbial community dominated by beneficial genera such as Pseudomonas and Bacillus after treatment. Molecular docking simulations confirmed cyanide binding to the bacterial enzymes, supporting the degradation mechanism. Our findings demonstrate that a targeted microbial consortium can detoxify CME-contaminated soils and restore soil health. This integrative structural–functional strategy provides a promising framework for sustainable remediation of cassava processing waste in agricultural lands.