Vincent N . Chigor - Academia.edu (original) (raw)

Papers by Vincent N . Chigor

Environmental Science and Pollution Research

Irrigation of fresh produce with poorly treated wastewater or contaminated freshwater sources can... more Irrigation of fresh produce with poorly treated wastewater or contaminated freshwater sources can lead to produce contamination and foodborne illnesses, as well as the dissemination of antimicrobial resistance determinants. In this study, we assessed the presence of integrons in multidrug-resistant Escherichia coli isolated from the University of Nigeria, Nsukka Wastewater Treatment Plant effluent, tap water, vegetables from irrigated gardens and vegetables sold in selected markets from Nsukka and Enugu cities. E. coli was isolated following standard laboratory procedure and confirmed through beta-glucuronidase (uidA)-targeted polymerase chain reaction (PCR). The antibiotic resistance of the isolates was determined using Bauer-Kirby disk diffusion assay, and multiplex PCR was used to determine the presence of class 1 and 2 integrons. Our result revealed a total of 188 E. coli isolates from WWTP effluent (n = 41), tap water (n = 10) and vegetables from greenhouse (n = 46), farms (n = 55) and market (n = 36). Multidrug resistance was detected in all the isolates, ranging from three-drug resistance in a single isolate to 7-drug resistance patterns in two different isolates. Of the total isolates, class 1 integrons were abundantly detected in 175 (93.1%) and class 2 in 5 (2.7%). All the class 2 integrons were found in isolates that were positive for class 1. The abundance of multidrug-resistant E. coli harbouring class 1 integrons in the effluent and vegetable samples is a potential public health risk. Therefore, the appropriate measures for the safe use of poorly treated wastewater for vegetable farm irrigation are required to be put in place to reduce the microbial load of the discharged effluent. Also, education of farmers and the community on the dangers of wastewater effluent-grown plants and proper methods for cleaning harvested vegetable is recommended.

Bio-Research, 2021

The epidemiological consequences of co-infections by enteric, wound, opportunistic, and drug-resi... more The epidemiological consequences of co-infections by enteric, wound, opportunistic, and drug-resistant pathogens, underscore the need for alternative and multi-target therapeutic approaches. Phytochemical properties of some plants are widely known but their potential utility as cheaper multi-target therapeutic options, have rarely been investigated. In the current work, Gongronema latifolium, Psidium guajava, and Aspilia africana extracts were studied for their potential utility as multi-target therapeutic alternatives. The plants were screened for phytochemical constituents. Based on the CLSI disc diffusion assay, the sensitivities of Escherichia coli, Klebsiella pneumoniae, Enterococcus faecalis, and Pseudomonas aeruginosa to the plants’ extracts were tested. The minimum inhibitory concentration of the extracts against susceptible bacteria was determined by CLSI broth microdilution protocols. The major families of plant bioactive compounds were detected, with alkaloids, terpenoids...

The Buffalo River and its dams are major surface water sources used for fresh produce irrigation,... more The Buffalo River and its dams are major surface water sources used for fresh produce irrigation, raw water abstraction and recreation in parts of the Eastern Cape Province in South Africa. Over a 12-month period (August 2010 to July 2011), we assessed the bacteriological qualities of water from the river and 3 source water dams along its course. Faecal indicator bacteria (FIB), including total coli-form (TC), faecal coliform (FC) and enterococci (ENT) counts, were high and ranged as follows: 1.9×102–3.8× 107, 0–3.0×105 and 0–5.3×105cfu/100 ml for TC, FC and ENT, respectively. Significantly (P<0.05) higher concentra-tions of FC and ENT were observed at the sampling sites located at the lower reaches of the river compared to the upper reaches, and at Bridle Drift Dam compared to the other two dams. FIB counts mostly exceeded the recom-mended maximum values suggested by national and inter-national guidelines for safe fresh produce irrigation, domestic applications, full-contact rec...

International Journal of Sciences, 2019

Pakistan Journal of Medical Sciences Online

Objective: Prevalence, antibiotic patterns and plasmid profiles of Enterohaemorrhagic Escherichia... more Objective: Prevalence, antibiotic patterns and plasmid profiles of Enterohaemorrhagic Escherichia coli (EHEC) 0157:H7 from humans and environmental sources were studied at various seasons of the year in Nigeria. Methodology: Stool and environmental samples were obtained from Lagos and Zaria and characterized as EHEC 0157:H7 using the method of Cowan and serotyping. The isolates were further characterized using antibiotic susceptibility testing and plasmid profile. Results: Out of 132 stool samples, 42 (31.8%) of EHEC 0157:H7 were isolated between April to December 2004. These samples were from Lagos (Western Nigeria) and Zaria (Northern Nigeria). Thirty-three isolates were from Lagos while 9 were from Zaria. Out of 90 environmental samples, 11 (12.2%) were positive for EHEC 0157:H7. The highest number of isolates (13) was obtained during the month of December, the dry, harmattan and festive season. Most of the isolates from Zaria were resistant to ampicillin, nitrofurantoin and tetr...

The Scientific World Journal, 2013

Chlorophenol compounds and their derivatives are ubiquitous contaminants in the environment. Thes... more Chlorophenol compounds and their derivatives are ubiquitous contaminants in the environment. These compounds are used as intermediates in manufacturing agricultural chemicals, pharmaceuticals, biocides, and dyes. Chlorophenols gets into the environment from a variety of sources such as industrial waste, pesticides, and insecticides, or by degradation of complex chlorinated hydrocarbons. Thermal and chemical degradation of chlorophenols leads to the formation of harmful substances which constitute public health problems. These compounds may cause histopathological alterations, genotoxicity, mutagenicity, and carcinogenicity amongst other abnormalities in humans and animals. Furthermore, the recalcitrant nature of chlorophenolic compounds to degradation constitutes an environmental nuisance, and a good understanding of the fate and transport of these compounds and their derivatives is needed for a clearer view of the associated risks and mechanisms of pathogenicity to humans and anima...

African Journal of …, 2010

International Journal of Environmental Science and Technology, 2013

Science of The Total Environment

Copyright © 2013 Etinosa O. Igbinosa et al. This is an open access article distributed under the ... more Copyright © 2013 Etinosa O. Igbinosa et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Chlorophenol compounds and their derivatives are ubiquitous contaminants in the environment. These compounds are used as intermediates in manufacturing agricultural chemicals, pharmaceuticals, biocides, and dyes. Chlorophenols gets into the environment from a variety of sources such as industrial waste, pesticides, and insecticides, or by degradation of complex chlorinated hydrocarbons. Thermal and chemical degradation of chlorophenols leads to the formation of harmful substances which constitute public health problems. These compounds may cause histopathological alterations, genotoxicity, mutagenicity, and carcinogenicity amongst other abnormalities in humans and animals. Furthermore, the recalcitrant nature of chlorophenolic c...

Abstract: Ethanolic and aqueous (hot and cold) extracts of the fruit pulp, stem bark and leaves o... more Abstract: Ethanolic and aqueous (hot and cold) extracts of the fruit pulp, stem bark and leaves of Tamarindus indica were evaluated for antibacterial activity, in vitro, against 13 Gram negative and 5 Gram positive bacterial strains using agar well diffusion and macro broth dilution techniques, simultaneously. The fruit pulp extracts exhibited a wide spectrum of activity; the cold water extract against 95.5 % of the test bacterial strains; and the hot water and ethanolic extracts against 90.9 % and 86.4%, respectively. In contrast the cold water extract of the leaves and stem bark, each was active against 16.7%; while the ethanolic extract of each was active against 75 % of the test strains. The minimum inhibitory concentrations (MIC) ranged from 7.81 mg/mL against Bacillus subtilis ATCC 6051 to 31.25 mg/mL against Escherichia coli ATCC 11775; and the minimum bactericidal concentration (MBC) ranged from 125 mg/mL against Pseudomonas aeruginosa ATCC 10145 to 250 mg/mL against Bacillu...

Agricultural Engineering International: The CIGR Journal, 2018

Access to safe and reliable water supply is a challenge in many parts of the developing world. Th... more Access to safe and reliable water supply is a challenge in many parts of the developing world. The use of roof harvested rainwater for domestic and potable purposes is common in households and farmsteads in the rainforest and some parts of savannah ecological zones of Nigeria in spite of the health risk associated with ingestion of water from an unimproved source such as untreated roof harvested rainwater. Solar photocatalysis has been proven to be effective in water treatment devoid of the short comings of high fuel cost and formation of carcinogens associated with conventional households water disinfection methods such as boiling and the use of chemicals. In this study, an automated photocatalytic batch reactor which uses solar radiation as its photon source was developed with materials sourced locally in Nigeria. The automated system injects contaminated water into the reactor tube and evacuates the water into the treated water tank upon the reception of a preset solar radiat...

This study investigates the pollution level of surface waters in Zaria, Nigeria. The bacteriologi... more This study investigates the pollution level of surface waters in Zaria, Nigeria. The bacteriological and physicochemical analyses performed were in accordance with standard procedures. Out of 228 samples from different sites, 128 (56.1%) had counts higher than the standards. Samaru stream was the most polluted. The frequency of contamination of samples with Escherichia coli O157 was only 2.2%. There was a positive correlation between faecal coliform count with most of the physicochemical parameters. The use of the surface waters as raw water for drinking, irrigation of food crops for raw consumption and for recreational activities may be hazardous. The study therefore, stresses on the need to control the faecal pollution of the bodies of water.

The contamination of fresh produce by irrigation waters has led to outbreaks of foodborne illness... more The contamination of fresh produce by irrigation waters has led to outbreaks of foodborne illness, yet treated wastewater presents itself as an attractive alternative to scarce quality water in the...