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Papers by Yinka Titilawo

African journal of pure and applied sciences, Dec 30, 2023

Deleted Journal, Apr 25, 2024

Journal of applied phycology, Feb 8, 2024

During wastewater treatment by integrated algal pond systems (IAPS), microalgal-bacterial flocs (... more During wastewater treatment by integrated algal pond systems (IAPS), microalgal-bacterial flocs (MaB-flocs) form naturally but periodically disaggregate, resulting in poor settling, low biomass recovery, and reduced effluent quality. This study investigates biotic/abiotic-induced changes in microbial community structure in high-rate algal oxidation ponds (HRAOP) of an IAPS on MaB-floc formation and stability during sewage treatment. Results show that dominance by Pseudopediastrum, Desmodesmus and Micractinium species in spring and summer and the chytrids, Paraphysoderma sp. in spring and Sanchytrium sp. in summer, occurred coincident with enhanced MaB-floc formation and biomass recovery (≥90%). In winter, poor floc formation and low biomass recovery were associated with dominance by Desmodesmus, Chlorella, and the Chlorella-like genus Micractinium. A principal components analysis (PCA) confirmed that combinations of colonial microalgae and associated parasitic chytrids underpin MaB-floc formation and stability in spring and summer and that unicells dominated in winter. Dominance by Thiothrix sp. coincided with floc disaggregation. Thus, changes in season, composition and abundance of colonial microalgae and associated parasitic fungi appeared to impact MaB-floc formation, whereas species composition of the bacterial population and emergence of Thiothrix coincided with floc instability and disaggregation.

Sustainable Water Resources Management, Nov 20, 2022

Water, Air, & Soil Pollution, 2021

Escherichia coli isolates, commonly found as gut microflora in warm-blooded animals, are classifi... more Escherichia coli isolates, commonly found as gut microflora in warm-blooded animals, are classified into the major phylogroups, A, B1, B2 and D, and further divided into subgroups: A0, A1, B1, B22, B23, D1 and D2. This study tracks and classifies E. coli strains along an integrated algal pond system (IAPS) during municipal sewage treatment. PCR-confirmed E. coli isolates were delineated into phylogroup by targeting genes chuA, yjaA and TSPE4.C2 using the triplex PCR assay. Antimicrobial susceptibility testing was by disk diffusion assay. A total of 120 E. coli isolates were confirmed by analysis of the uidA gene. Phylogenetic analysis revealed 57 isolates were group A with others in groups B2 (35), B1 (16) and D (12). Isolate susceptibility to antibiotics was norfloxacin > florfenicol > gatifloxacin > streptomycin > gentamicin. Nearly all isolates (117, 98%) were sulphamethoxazole- and penicillin G-resistant (115, 96%). Thus, resistance was manifest by all phylogroups and to 3–17 of drugs tested. These findings confirm presence of various multidrug-resistant E. coli phylogroups throughout the IAPS wastewater treatment process and emphasize the usefulness of multidrug resistance profiling as a tool for microbial source tracking and, with which to determine origin of faecal pollution.

Processes, 2020

Coal mining produces large quantities of discard that is stockpiled in large dumps. This stockpil... more Coal mining produces large quantities of discard that is stockpiled in large dumps. This stockpiled material, termed coal discard, poses an environmental threat emphasising the need for appropriate bioremediation. Here, metagenomic analysis of the 16S rRNA from ten coal-degrading strains previously isolated from coal slurry from discard dumps and from the rhizosphere of diesel-contaminated sites was used to establish genetic relatedness to known plant growth-promoting (PGP) bacteria in the NCBI database. Measurement of indole and ammonium production and solubilisation of P and K were used to screen bacteria for PGP characteristics. BLAST analysis revealed ≥ 99% homology of six isolates with reference PGP strains of Bacillus, Escherichia, Citrobacter, Serratia, Exiguobacterium and Microbacterium, while two strains showed 94% and 91% homology with Proteus. The most competent PGP strains were Proteus strain ECCN 20b, Proteus strain ECCN 23b and Serratia strain ECCN 24b isolated from di...

Heliyon, 2020

Background: Occurrences of pathogens in environmental and irrigation waters, as well as the use o... more Background: Occurrences of pathogens in environmental and irrigation waters, as well as the use of inadequately treated sewage for fresh produce constitute potential public health threats worldwide. Objective: To investigate the treated wastewater used in fresh produce irrigation in Nsuskka, Southeastern Nigeria, as a reservoir enterotoxigenic and multidrug-resistant Escherichia coli. Methods: Treated wastewater (from the sewage treatment facility at Nsukka, Southeast Nigeria), soil and irrigated vegetable samples were collected and analyzed using standard procedures. Escherichia coli isolated from the samples were screened for the presence of enterotoxigenic E. coli strain encoding lt gene and profiled for antibiotic resistance using the conventional PCR and standardized agar disk diffusion assays respectively. Results: Of the total presumptive 103 isolates, PCR detected uidA gene in 87 (84 %), of which 23 (26 %) harboured the lt encoding ETEC gene. Generally, imipenem, cefuroxime and norfloxacin proved to be most effective of all the antibiotics employed. Wastewater isolates were variously susceptible to ciprofloxacin (95 %), norfloxacin (95 %), cefuroxime (93 %), chloramphenicol (93 %), trimethoprim and tetracycline (88 %), soil isolates to streptomycin (75 %) and vegetable isolates to cefuroxime (90 %), norfloxacin (86 %), ciprofloxacin (81 %) and chloramphenicol. Contrariwise, high resistances observed to other antibiotics were in the order; ampicillin (95 %), penicillin (93 %), erythromycin (90 %) and clarithromycin (83 %) among wastewater isolates, ciprofloxacin and norfloxacin (75 %) in soil isolates; penicillin, vancomycin and erythromycin (98 %), rifampicin and clarithromycin (93 %), sulphamethoxazole (83 %), ampicillin (81 %), tetracycline and imipenem (76 %), trimethoprim (72 %) and amoxicillin (71 %) among vegetable isolates, with multidrug resistance patterns ranging from three to seventeen. Conclusions: Our results reveal the treated wastewater as a reservoir of enterotoxigenic E. coli as well as multidrug resistance that may pose a health hazard for humans and animals when released to the natural environment. Hence, there is need to develop management strategies and ensure compliance in order to prevent water-borne diarrhoea caused by ETEC and reduce the menace of antibiotic resistance in the environment.

International Journal of Energy and Water Resources, 2020

We assessed the quality status of surface and ground waters used for drinking in Ikwo, Southeast ... more We assessed the quality status of surface and ground waters used for drinking in Ikwo, Southeast Nigeria, using the physicochemical and bacteriological qualities, and antimicrobial susceptibility profiles following standard procedures. Overall. the mean values of the physicochemical qualities of the water samples revealed the following: colour (brown/dark-brown/ colourless), odour (objectionable), temperature (28-30 °C), pH (6.30-7.50), electrical conductivity (12.94-12.99 µs cm −1), total dissolved solids (7.74-7.80 mg L −1), alkalinity (0.3-1.4 mg L −1), hardness (19-252 mg L −1), chloride (0.8-3.1 mg L −1), copper (0.01-0.72 mg L −1) and zinc (0.03-1.49 mg L −1). Only nitrate was not detected all through. Likewise, total heterotroph, coliform and Escherichia coli counts ranged from 1.16 to 6.96 × 10 3 cfu mL −1 , 150 to 2400 MPN/100 mL and 45 to 345 CFU/100 mL, respectively. The antimicrobial susceptibility profiles showed that the E. coli isolates were relatively susceptible to gentamycin (58%) and levofloxacin (50%), with high percentages of the isolates displaying resistance against tetracycline (78%), norfloxacin (76%), nalidixic acid (76%), augmentin (68%), ampiclox (62%), doxycycline (62%) and amoxil (52%). While the physicochemical parameters were generally within the permissible limits of the WHO guidelines, reverse is the case for the bacteriological loads. Exceedance of bacteriological water quality criteria and prevalence of multidrugresistant E. coli indicate high levels of microbial and drug pollutants in the waters, rendering them unfit for direct human ingestion without proper pretreatment.

AMB Express, 2018

Identification of fungal species based on morphological characteristics is tedious, complex, pron... more Identification of fungal species based on morphological characteristics is tedious, complex, prone to errors, and thus cannot be completely relied upon. In this study, internal transcribed spacers (ITS 1 and 4)-polymerase chain reaction was employed to amplify DNA of 19 mushroom isolates collected at Environmental Pollution Science and Technology farm, Ilesa, Southwest Nigeria. The PCR amplification of ITS1 and 4 of the mushrooms isolates yielded approximately 850 bp. Amplicons obtained were sequenced and identified using BLASTn in the NCBI. The BLASTn results revealed that Termitomyces aurantiacus (3), Tricholoma matsutake (8), Tricholoma robustum (2), P. ostreatus (4), Schizophyllum commune (1) and Pleurotus pulmonarius (1) were fully represented. Only Tricholoma matsutake (KT273371), Pleurotus pulmonarius (KY962469) and Tricholoma matsutake (AF438605) had 100% similarity with reference strain. However, the phylogenetic analysis of the isolates showed low genetic relatedness with reference strains. This study revealed the novelty of the mushroom strains and thus advocating the need for strict conservation measures and further investigations on their potential benefits to mankind.

Polish Journal of Environmental Studies, 2019

Rivers are important freshwater resources for domestic and industrial activities, and the availab... more Rivers are important freshwater resources for domestic and industrial activities, and the availability of good-quality freshwater is indispensable for preventing water-borne diseases and improving quality of life, especially in communities that lack a water supply system. The physicochemical parameters and coliform distribution of some selected rivers in Osun State, soutwestern Nigeria were evaluated using standard analytical procedures. The physicochemical qualities ranged as follows: pH (6.9-7.6), temperature (26-29ºC), turbidity (2.28 = 9.46 NTU), electrical conductivity (229-581 μS/cm), nitrate (0.03-0.05 mg/L), nitrite (0.00-0.01 mg/L), sulphate (3.33-20.33 mg/L), chloride ions (7.83-27.33 mg/L), dissolved oxygen (4.23-5.57 mg/L), total dissolved solids (56-184 mg/L), total hardness (78-519 mg/L) and alkalinity (50.67-146.67 mg/L). Total coliforms were detected in counts ranging from 59 to 176 CFU/100 ml of water sample. One-way ANOVA showed that pH, temperature, electrical conductivities, nitrates, nitrites, chloride, dissolved oxygen, total dissolved solid, total hardness and alkalinity were significantly different (P<0.05), whereas turbidity and sulphate were not significantly different (P>0.05) from each parameter with respect to sampling sites. Generally, results from this study suggest that the river waters are not suitable for consumption, domestic or recreational use, and confirm the importance of protecting the freshwater resources of southwestern Nigeria.

INTERNATIONAL JOURNAL OF EDUCATIONAL SCIENCES, 2015

Based on theoretical overviews covering feedback and partners in teaching practice, this paper re... more Based on theoretical overviews covering feedback and partners in teaching practice, this paper reports on a cohort of South African third year B.Ed. student teachers' impressions of feedback during a specific period of teaching practice by means of a quantitative study. By focusing on feedback on lesson presentations, 82 randomly sampled student teachers shared their impressions of feedback provided by supervisor teachers and university lecturers. Although the findings suggest that student teachers experience feedback of university lecturers as of higher quality than feedback provided by supervisor teachers, much must still be done to improve feedback practices during teaching practice periods.

Chemosphere, 2018

BMC Microbiology, 2015

Background: Diarrhoeal diseases are attributable to unsafe water stemming from improper sanitatio... more Background: Diarrhoeal diseases are attributable to unsafe water stemming from improper sanitation and hygiene and are reportedly responsible for extensive morbidity and mortality particularly among children in developed and developing countries. Methods: Water samples from selected rivers in Osun State, SouthWestern Nigeria were collected and analyzed using standard procedures. Escherichia coli isolates (n=300) were screened for 10 virulence genes using polymerase chain reaction for pathotyping. Results: While the virulence gene (VG) lt for enterotoxigenic E. coli had the highest prevalence of 45 %, the enteropathogenic E. coli genes eae and bfp were detected in 6 and 4 % of the isolates respectively. The VGs stx1 and stx2 specific for the enterohemorrhagic E. coli pathotypes were detected in 7 and 1 % of the isolates respectively. Also, the VG eagg harboured by enteroaggregative pathotype and diffusely-adherent E. coli VG daaE were detected in 2 and 4 % of the isolates respectively and enteroinvasive E. coli VG ipaH was not detected. In addition, the VGs papC for uropathogenic and ibeA for neonatal meningitis were frequently detected in 19 and 3 % of isolates respectively. Conclusions: These findings reveal the presence of diarrhoeagenic and non-diarrhoeagenic E. coli in the selected rivers and a potential public health risk as the rivers are important resources for domestic, recreational and livelihood usage by their host communities.

Science of The Total Environment, 2015

Escherichia coli isolates were recovered from some rivers in Southwestern Nigeria. • The antibiog... more Escherichia coli isolates were recovered from some rivers in Southwestern Nigeria. • The antibiogram of the isolates were evaluated including relevant resistance genes. • β-lactams and tetracyclines resistance determinants were more frequent. • Phenicols and aminoglycosides resistance determinant were less frequent. • Significant positive associations existed among ampC, bla TEM , bla Z and tetA genes.

Environmental Science and Pollution Research, 2015

We evaluated the antibiogram profile of Escherichia coli (n=300) isolated from selected rivers in... more We evaluated the antibiogram profile of Escherichia coli (n=300) isolated from selected rivers in Osun State, Nigeria. The identities of the E. coli isolates were confirmed by polymerase chain reaction (PCR) technique. Susceptibility of the isolates to 20 antibiotics conventionally used in clinical cases was assessed in vitro by the standardized agar disc-diffusion method. All the isolates were susceptible to imipenem, meropenem, amikacin and gatilofloxacin. The isolates were variously susceptible to the other antibiotics as follows: ciprofloxacin (96 %), kanamycin (95 %), neomycin (92 %), streptomycin (84 %), chloramphenicol (73 %), nalidixic acid (66 %), nitrofurantoin (64 %), gentamycin (63 %), doxycycline (58 %), cefepime (57 %), tetracycline (49 %) and cephalothin (42 %). The multiple antibiotic resistance indexing ranged from 0.50 to 0.80 for all the sampling locations and exceeded the threshold value of 0.2, suggesting the origin of the isolates to be of high antimicrobial usage. Our findings signify an increase in the incidence of antimicrobial resistance of E. coli towards conventionally used antibiotics necessitating proper surveillance programmes towards the monitoring of antimicrobial resistance determinants in water bodies.

In spite of treated wastewater presenting itself as an attractive alternative to scarce quality w... more In spite of treated wastewater presenting itself as an attractive alternative to scarce quality water in the developing countries, the associated contamination of fresh produce by irrigation waters leading to outbreak of foodborne illnesses is on the rise. Horizontal transfer of integrons play important role in the spread and maintenance of antimicrobial resistance among strains of Escherichia coli. This study assessed the effluents from the University of Nigeria, Nsukka Wastewater Treatment Plant (UNN-WWTP) as well as vegetables irrigated with the effluent, and vegetables sold in selected markets from Nsukka and Enugu cities for the presence of E. coli and determined the prevalence integrons in multidrug-resistant isolates. Isolation of E. coli was done using eosin methylene blue agar and isolates subjected to Gram staining for identification of presumptive colonies. Confirmation of E. coli was achieved by polymerase chain reaction (PCR) technique, targeting beta-glucuronidase (uid...

Environmental Science and Pollution Research

This study evaluated levels of heavy metals and macro-elements in ten major rivers in Osun State,... more This study evaluated levels of heavy metals and macro-elements in ten major rivers in Osun State, Southwest Nigeria. Triplicate water samples collected from selected rivers were analyzed for metal pollutants by atomic absorption spectrophotometry. Concentrations were obtained as follows: iron: 60 – 960 g L-1; manganese: ND – 3 µg L-1; chromium 0 – 2100 µg L-1; aluminium: 0 – 800 µg L-1 ; copper: 0 – 1350 µg L-1; zinc: 10 – 650 µg L-1; calcium: 6400 – 232000 µg L-1 and magnesium: 2000 – 71000 µg L-1 but lead (Pb) was not detected all through. While most of the parameters fell within the threshold values for drinking water, iron, chromium, aluminium and calcium exceeded at some locations. The order of pollution of the rivers, especially with heavy metals had the order: R8 > R3 > R2 > R5 > R10 > R6 > R4 > R1 > R7 > R9; which implies that R8 and R3 are the most polluted. The health risk assessment results revealed that hazard quotient (HQ) and hazard index (HI) were below the acceptable limit of 1.0, suggesting no substantial non-carcinogenic effect would arise from individual exposure to the elements. However, the high carcinogenic risk values were 3.18 × 10-6 and 4. 43 × 10-6 for adults and children, respectively at R8, implying that 1 person in every 314,206 adults and 225,836 children drinking from the water may be at risk of having cancer correspondingly. Hence, there is need to moderate the levels of these pollutants in these waterbodies to safeguard public health.