Heavy Metal Loading in Surface Sediments along the Kawere Stream, Tarkwa, Ghana

Sediment contamination by heavy metals resulting from anthropogenic activities is increasingly becoming a global concern due to the risk it poses to human well-being and ecological integrity at large. The purpose of this study was to assess the heavy metals loading in sediment along the Kawere stream. Ten sediment samples were collected, acid digested and analysed for copper (Cu), lead (Pb), cadmium (Cd), manganese (Mn), zinc (Zn), nickel (Ni), chromium (Cr), cobalt (Co) and iron (Fe) using a Varian AA240FS Atomic Absorption Spectrometer (AAS). The Australian and New Zealand Environment and Conservation Council (ANZECC) guidelines for freshwater sediment quality was used as the benchmark against which the measured metal concentrations were compared. Nemerow’s pollution and potential ecological risk indices were used to evaluate the pollution status and ecological risk levels of the heavy metals in the stream. The results obtained indicated that, except Cu which exceeded the ANZECC trigger value of 65 mg/kg at three sampling sites (K01=171.29 mg/kg, K05=170.83 mg/kg and K07=113.31 mg/kg), all other measured heavy metals concentrations were below their corresponding ANZECC values. Heavy metal pollution assessment showed that three samples (K01, K05 and K07) were slightly polluted, suggesting the likelihood of posing a health threat to the aquatic organisms and humans. Calculated Ecological Risk Index (RI) ranged from 3.229 to 19.750 (RI < 150), representing a low ecological risk. As such, the metals, Cu, Ni, Cd, Pb, Cr, and Zn pose a low ecological risk to the aquatic ecosystem. Although the ecological risk is low based on the current results, constant monitoring of the stream quality is recommended due to the increasing human activities along the stream as well as the sediments ability to accumulate and remobilise heavy metals back into the water column and possibly transferring them through the food chain.   Keywords: Heavy Metals, Sediment, Ecological Risk Assessment, Pollution, Strea

Effects of Fish Cage Culture on Water and Sediment Quality in the Gorge Area of Lake Volta in Ghana: A Case Study of Lee Fish Cage Farm

The study determined the impacts of fish cage farming on the gorge area of Lake Volta. Water and sediment samples were collected from six sites in the Lee Cage Farm; four from sections with cages and two from about 1300 m upstream of the farm which served as the control. Water quality variables monitored were pH, temperature, dissolved oxygen, nitrate-nitrogen, ammonia-nitrogen, orthophosphate, faecal coliforms and total coliforms. Variables monitored in the sediment were organic matter, total carbon, total nitrogen and total phosphorus. There were variations in water quality between the farmed and control sites but the differences were not significant (p > 0.05). The mean counts of total coliform in the water ranged from 940 - 3318 cfu/100 ml while faecal coliforms ranged from 113 - 552 cfu/100 ml at the farmed site. The mean total coliform count at the control site ranged from 837 - 6960 cfu/100 ml while the faecal coliforms ranged from 48 - 120 cfu/100 ml. Therefore, there was significant variation between the faecal coliforms count at the two sites (p = 0.046). The results suggest that the general microbiological quality of the water at the study area was unacceptable

High prevalence of multidrug resistant ESBL- and plasmid mediated AmpC-producing clinical isolates of Escherichia coli at Maputo Central Hospital, Mozambique

Background: Epidemiological data of cephalosporin-resistant Enterobacterales in Sub-Saharan Africa is still restricted,and in particular in Mozambique. The aim of this study was to detect and characterize extended-spectrum β-lactamase (ESBL) - and plasmid-mediated AmpC (pAmpC)-producing clinical strains of Escherichia coli at Maputo Central Hospital (MCH), a 1000-bed reference hospital in Maputo, Mozambique. Methods: A total of 230 clinical isolates of E. coli from urine (n = 199) and blood cultures (n = 31) were collected at MCH during August–November 2015. Antimicrobial susceptibility testing was performed by the disc diffusion method and interpreted according to EUCAST guidelines. Isolates with reduced susceptibility to 3rd generation cephalosporins were examined further; phenotypically for an ESBL−/AmpC-phenotype by combined disc methods and genetically for ESBL- and pAmpC-encoding genes by PCR and partial amplicon sequencing as well as genetic relatedness by ERIC-PCR. Results: A total of 75 isolates with reduced susceptibility to cefotaxime and/or ceftazidime (n = 75) from urine (n = 58/199; 29%) and blood (n = 17/31; 55%) were detected. All 75 isolates were phenotypically ESBL-positive and 25/75 (33%) of those also expressed an AmpC-phenotype. ESBL-PCR and amplicon sequencing revealed a majority of blaCTX-M (n = 58/75; 77%) dominated by blaCTX-M-15. All AmpC-phenotype positive isolates (n = 25/75; 33%) scored positive for one or more pAmpC-genes dominated by blaMOX/FOX. Multidrug resistance (resistance ≥ three antibiotic classes) was observed in all the 75 ESBL-positive isolates dominated by resistance to trimethoprimsulfamethoxazole, ciprofloxacin and gentamicin. ERIC-PCR revealed genetic diversity among strains with minor clusters indicating intra-hospital spread. Conclusion: We have observed a high prevalence of MDR pAmpC- and/or ESBL-producing clinical E. coli isolates with FOX/MOX and CTX-Ms as the major β-lactamase types, respectively. ERIC-PCR analyses revealed genetic diversity and some clusters indicating within-hospital spread. The overall findings strongly support the urgent need for accurate and rapid diagnostic services to guide antibiotic treatment and improved infection control measures

DOI: 10.5897/JSSEM12.068 ISSN 2141-2391 ©2013 Academic Journals Full Length Research Paper Nematode pests of plantain: A case study of Ashanti and Brong Ahafo regions of Ghana

A survey of plantain farms was conducted in April 2012 at four locations in two districts of Ghana. The purpose was to identify plant parasitic nematodes (PPN) associated with plantain production in Ghana. The locations were Adomakokrom and Kenyasi in the Brong Ahafo, Adanwomase and Mpobi in the Ashanti region. Demographic and sociological data of farmers, plantain root lesion scores, PPN populations per 200 cm 3 soil and 5 g plantain roots were analyzed. Nematode damage to root at Adomakokrom, Adanwomase, Mpobi and Kenyasi were 50, 75, 75 and 50%, respectively. Five nematode species were recovered from the rhizosphere of plantain. The nematodes were in the order of importance; Pratylenchus coffeae, Meloidogyne spp., Rotylenchulus reniformis, Radopholus similis and Helicotylenchus multicintus. High populations of P. coffeae (803/200 cm 3), H. multicintus (292/200 cm 3) and R. reniformis (343/200 cm 3) were extracted from soil samples at Adomakokrom, Adanwomase and Adanwomase respectively. Four parasitic nematodes; Meloidogyne spp., P. coffeae, R. reniformis and R. similis were extracted from plantain roots. Root populations were higher compared with soil samples. For sustainable plantain production in Ghana, an efficient management option must be devised. Key words: Ghana, integrated pest management, Musa spp., plant parasitic nematodes

Agronomic potentials of quality protein maize hybrids developed in Ghana

A quality protein maize (QPM) hybrid programme was started in 1991 to develop and promote high and stableyielding QPM hybrids to increase production of nutritionally superior maize varieties in Ghana. Six 3- way QPM hybrids developed from inbred lines originating from germplasm of the International Centre for Maize and Wheat Improvement (CIMMYT) were evaluated on research stations and in farmers\' fields in Ghana from 1995 to 1996. In the on-station evaluations, grain yields across 10 sites in both years averaged 6.0 ton ha-1 for the three hybrids (GH132-28, GH110-5 and GH2328-88), 5.22 ton ha-1 for Obatanpa, and 3.60 ton ha-1 for the local maize variety. In farmers\' fields, data from over 50 farm sites in 1995 and 1996 showed mean yields of 4.95 ton ha-1 for the three hybrids, and 4.28 ton ha-1 for Obatanpa compared to 3.59 ton ha-1 for farmers\' varieties. On the average, the hybrids were similar to Obatanpa in days to 50 per cent silking, but were shorter in plant height and ear placement. Consumer preference tests showed that the three hybrids were rated similar to the local variety in popular traditional food preparations such as ‘kenkey\' and ‘tuo zafi\'. In 1997, the National Variety Release Committee approved the release of GH132-28, GH110-5, and GH2328-88 under the local names Dadaba, Mamaba, and CIDA-ba, respectively. These hybrids are recommended for planting in all the major agro-ecologies to boost maize production in Ghana.Les variétés de maïs hybride (Zea mays L.) dont les plus sésirées que les variétés de pollinisation libre à cause de leur uniformté et leurs potentiels de rendement plus élevés. Pour augmenter la production de variétés de maïs nutritionnellement supérieures au Ghana, I\'Institut de Recherche de Cultures a mis en place un programme hybrid de maïs protéique de qualité (MPQ) en 1991 pour développer et promouvoir des hybrides de MPQ de rendement élevés et stable. Six hybrids en trois de MPQ développés d\'issu de la même souch provenant de germeplasmes de CIMMYT (Centre International pour I\'amélioration de maïs et de blé) étaient évalués aux stations de recherches et aux champs d\'agriculteurs au Ghana de 1995 à 1996. Dans les évaluations sur place, les rendements de grain à travers 10 sites dans les deux années ont atteint la moyenne de 6.0 ton ha-1 pour les trois hybrids (GH132-28, GH110-5 et GH2328-88), 5.22 ton ha-1 pour \'Obatanpa\' et 3.60 ton ha-1 pour la variétés de maïs local. Sur les champs d\'agriculteurs des données de plus que 50 sites de champs en 1995 et 1996 montraient les rendements moyens de 4.95 ton ha-1 pour les trois hybrids et 4.28 ton ha-1 pour les \'Obatanpa\' comparées à 3.59 ton ha-1 pour les variétés d\'agriculteurs. En moyenne, les hybrides étaient semblables à \'Obatanpa\' en jours jusqu à 50% d\'apparition de soie maïs étaient plus courtes en taille de plante et en placement d\'épi. Les essais de préférence de consommateur montraient que les trios hybrides étaient évalués semblables à la variété locale dans les préparations de nouriture traditionnelle populaire telle que \'kenkey\' et \'tuo zafi\'. En 1997, le comité pour la mise en vente de Variété Nationale a approuvé la mise en vente de GH132-28, GH110-5 et GH2328-88 sous les noms locaux respectifs de Dadaba, Mamaba, et CIDA-ba. Ce hybrides sont recommandés pour la popultion dans toutes les agroéclogies majeures pour stimuler la production de maïs au Ghana. Ghana Journal of Agricultural Science Vol. 40 (1) 2007: pp. 81-8

Analysis of drug resistance among difficult-to-treat tuberculosis patients in Ghana identifies several pre-XDR TB cases

BACKGROUND: Resistance to tuberculosis (TB) drugs has become a major threat to global control efforts. Early case detection and drug susceptibility profiling of the infecting bacteria are essential for appropriate case management. The objective of this study was to determine the drug susceptibility profiles of difficult-to-treat (DTT) TB patients in Ghana. METHODS: Sputum samples obtained from DTT-TB cases from health facilities across Ghana were processed for rapid diagnosis and detection of drug resistance using the Genotype MTBDRplus and Genotype MTBDRsl.v2 from Hain Life science. RESULTS: A total of 298 (90%) out of 331 sputum samples processed gave interpretable bands out of which 175 (58.7%) were resistant to at least one drug (ANY(r)); 16.8% (50/298) were isoniazid-mono-resistant (INH(r)), 16.8% (50/298) were rifampicin-mono-resistant (RIF(r)), and 25.2% (75/298) were MDR. 24 (13.7%) of the ANY(r) were additionally resistant to at least one second line drug: 7.4% (2 RIF(r), 1 INH(r), and 10 MDR samples) resistant to only FQs and 2.3% (2 RIF(r), 1 INH(r), and 1 MDR samples) resistant to AMG drugs kanamycin (KAN), amikacin (AMK), capreomycin (CAP), and viomycin (VIO). Additionally, there were 4.0% (5 RIF(r) and 2 MDR samples) resistant to both FQs and AMGs. 81 (65.6%) out of 125 INH-resistant samples including INH(r) and MDR had katG-mutations (MT) whereas 15 (12%) had inhApro-MT. The remaining 28 (22.4%) had both katG and inhA MT. All the 19 FQ-resistant samples were gyrA mutants whereas the 10 AMGs were rrs (3), eis (3) as well as rrs, and eis co-mutants (4). Except for the seven pre-XDR samples, no sample had eis MT. CONCLUSION: The detection of several pre-XDR TB cases in Ghana calls for intensified drug resistance surveillance and monitoring of TB patients to, respectively, ensure early diagnosis and treatment compliance

Genome-wide analysis of ivermectin response by Onchocerca volvulus reveals that genetic drift and soft selective sweeps contribute to loss of drug sensitivity

Treatment of onchocerciasis using mass ivermectin administration has reduced morbidity and transmission throughout Africa and Central/South America. Mass drug administration is likely to exert selection pressure on parasites, and phenotypic and genetic changes in several Onchocerca volvulus populations from Cameroon and Ghana-exposed to more than a decade of regular ivermectin treatment-have raised concern that sub-optimal responses to ivermectin's anti-fecundity effect are becoming more frequent and may spread.Pooled next generation sequencing (Pool-seq) was used to characterise genetic diversity within and between 108 adult female worms differing in ivermectin treatment history and response. Genome-wide analyses revealed genetic variation that significantly differentiated good responder (GR) and sub-optimal responder (SOR) parasites. These variants were not randomly distributed but clustered in ~31 quantitative trait loci (QTLs), with little overlap in putative QTL position and gene content between the two countries. Published candidate ivermectin SOR genes were largely absent in these regions; QTLs differentiating GR and SOR worms were enriched for genes in molecular pathways associated with neurotransmission, development, and stress responses. Finally, single worm genotyping demonstrated that geographic isolation and genetic change over time (in the presence of drug exposure) had a significantly greater role in shaping genetic diversity than the evolution of SOR.This study is one of the first genome-wide association analyses in a parasitic nematode, and provides insight into the genomics of ivermectin response and population structure of O. volvulus. We argue that ivermectin response is a polygenically-determined quantitative trait (QT) whereby identical or related molecular pathways but not necessarily individual genes are likely to determine the extent of ivermectin response in different parasite populations. Furthermore, we propose that genetic drift rather than genetic selection of SOR is the underlying driver of population differentiation, which has significant implications for the emergence and potential spread of SOR within and between these parasite populations

Deletion of parasite immune modulatory sequences combined with immune activating signals enhances vaccine mediated protection against filarial nematodes

<p>Background: Filarial nematodes are tissue-dwelling parasites that can be killed by Th2-driven immune effectors, but that have evolved to withstand immune attack and establish chronic infections by suppressing host immunity. As a consequence, the efficacy of a vaccine against filariasis may depend on its capacity to counter parasite-driven immunomodulation.</p> <p>Methodology and Principal Findings: We immunised mice with DNA plasmids expressing functionally-inactivated forms of two immunomodulatory molecules expressed by the filarial parasite Litomosoides sigmodontis: the abundant larval transcript-1 (LsALT) and cysteine protease inhibitor-2 (LsCPI). The mutant proteins enhanced antibody and cytokine responses to live parasite challenge, and led to more leukocyte recruitment to the site of infection than their native forms. The immune response was further enhanced when the antigens were targeted to dendritic cells using a single chain Fv-αDEC205 antibody and co-administered with plasmids that enhance T helper 2 immunity (IL-4) and antigen-presenting cell recruitment (Flt3L, MIP-1α). Mice immunised simultaneously against the mutated forms of LsALT and LsCPI eliminated adult parasites faster and consistently reduced peripheral microfilaraemia. A multifactorial analysis of the immune response revealed that protection was strongly correlated with the production of parasite-specific IgG1 and with the numbers of leukocytes present at the site of infection.</p> <p>Conclusions: We have developed a successful strategy for DNA vaccination against a nematode infection that specifically targets parasite-driven immunosuppression while simultaneously enhancing Th2 immune responses and parasite antigen presentation by dendritic cells.</p&gt

The transcriptional response of Caenorhabditis elegans to ivermectin exposure identifies novel genes involved in the response to reduced food intake

We have examined the transcriptional response of Caenorhabditis elegans following exposure to the anthelmintic drug ivermectin (IVM) using whole genome microarrays and real-time QPCR. Our original aim was to identify candidate molecules involved in IVM metabolism and/or excretion. For this reason the IVM tolerant strain, DA1316, was used to minimise transcriptomic changes related to the phenotype of drug exposure. However, unlike equivalent work with benzimidazole drugs, very few of the induced genes were members of xenobiotic metabolising enzyme families. Instead, the transcriptional response was dominated by genes associated with fat mobilization and fatty acid metabolism including catalase, esterase, and fatty acid CoA synthetase genes. This is consistent with the reduction in pharyngeal pumping, and consequential reduction in food intake, upon exposure of DA1316 worms to IVM. Genes with the highest fold change in response to IVM exposure, cyp-37B1, mtl-1 and scl-2, were comparably up-regulated in response to short–term food withdrawal (4 hr) independent of IVM exposure, and GFP reporter constructs confirm their expression in tissues associated with fat storage (intestine and hypodermis). These experiments have serendipitously identified novel genes involved in an early response of C. elegans to reduced food intake and may provide insight into similar processes in higher organisms