Antibiotics resistance genes (ARGs) in environmental samples have been implicated in the clinical spread of resistance to antibiotics. This study was therefore aimed at the metagenomic assessment of ARGs from various environmental samples. Benthic, epipellic, estuary and soil samples were collected and analyzed for physicochemical parameters using standard techniques and ARGs via metagenomics. Metagenomic DNA was extracted from the various samples and sequenced on Miseq Illumina platform. Following next generation sequencing, gene calling was performed on the assembled sequence reads using FragGeneScan to predict open reading frames (ORFs), which were functionally annotated to various taxonomic groups using the Kyoto Encyclopedia of Genes and Genomes (KEGG) and Ghost KOALA databases. Results of physicochemical analysis showed anthropogenic influence in the various environments. Furthermore, a total of 12 types of ARGs were identified, that belongs to the RND and ABC superfamilies of ARGs. These were dominated by five classes of bacteria which were Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria, Deltaproteobacteria, and the Firmicutes (Clostridia). Our findings suggest that ARGs diversity differs with samples; with soil being the most abundant and only sample with the multidrug resistant efflux pumps. Further studies aimed at building a repository of ARGs genes in various environments should be carried out.
The present investigation was carried out during two consecutive seasons 2015 and 2016 in fruit nursery of faculty of Agriculture at Moshtohor, Benha University, in order to throw some spotlight on the impact of some chemical substances (Ethylmethanesulphonate – EMS in 10, 20 and 30 ppm); (colchicine at concentrations of 1%, 2% and 3%) and (benzyl adenine – BA, at concentrations of 1,2% and 3%) on seed germination %, seed germination rate, some seedling growth measurements and cytological examination of root tip of Carica papaya cv. Solo. The treatments were arranged in complete randomized block design with nine replicates (polyethylene bags), however, each replicate was represented by two papaya seedlings. The seedlings were divided into three categories according to their growth vigor, each category represented by three replicates for each treatment and subsequently each category sampled by 60 seedlings for all studied treatments. Seedling growth and chromosomal behavior as imported by the three studied chemical substances were evaluated on the 1st week of December. Data obtained revealed that both BA at 2% and BA 3% increased significantly germination %, germination rate and growth measurements. On the contrary, the least significant increase was always in concomitant to EMS at 3% and colchicine at 3 % during both experimental seasons. Moreover, EMS was more inhibitor of cell division followed by BA than Colchicine. This may be due to more damage resulted by BA and EMS affected on DNA replication during mitosis.
Aim: Maize (Zea mays L.) is the third most important food grain for humankind after rice and wheat. Therefore, the aim of this study is to evaluate the phenotypic variations in eight maize varieties under moisture stress.
Materials and Methods: All the varieties were grown with 3 replications in 75 cm deep polyethylene bags containing soil from study area for 30 days under four moisture stress conditions i.e. 25%, 50%, 75% and 100% of Field Capacity (FC) in green house.
Results: Significant variation existed in plant height, primary root length, root dry weight and shoot dry weight under different moisture conditions. The plant height and primary root length of maize seedlings under drought condition decreased in all tested maize varieties from 100% to 25% of moisture content. The average primary root length ranged from 27.5 to 88 cm. Melkassa 02 variety showed highest primary root length whereas, lowest mean root length was observed in Hora variety. Root and shoot dry weight also showed significant differences among eight maize varieties at different moisture levels. Each variety was also evaluated for ratio of root to shoot dry weight at different moisture levels in comparison to control. At 25% of FC, Pioneer variety recorded highest value for root to shoot ratio of dry weight with 2.4 fold increased followed by Hora, BH140, and Melkassa 02. Melkassa 04 reported least value for root to shoot ratio.
Conclusion: Results of our study has major implication for future breeding in maize. Under different condition of moisture stress, variations in maize morphological characteristics were observed. Thus more sampling should be done in future where maize is grown under adequate drought tolerance strategy.
In the Niger Delta region of Nigeria, the major anthropogenic source of xenobiotics is petroleum based hydrocarbons. Studies suggest that hydrocarbon degradation genes with potential for bioremediation have a greater abundance at equatorial biomes. Therefore, the primary aim of this study was to establish the distribution of hydrocarbon utilizing genes and metabolic activities in different ecosystems in Eastern Obolo in the Niger Delta and correlate same with total petroleum hydrocarbons contents of these ecosystems. Samples were designated as 1 to 5 (two soil samples: 1 and 2), epipellic and benthic sediment samples (3 and 4), and estuary water (5) samples). Sample collection, determination of total petroleum hydrocarbon (TPH) contents and molecular analyses were all done using standard methods. Extracted DNAs from the various samples were then subjected to next generation sequencing on Miseq Illumina platform.
Gene calling was then performed on the assembled sequence reads using Frag Gene Scan to predict open reading frames (ORFs). The ORFS were then functionally annotated to various taxonomic groups using the Kyoto Encyclopedia of Genes and Genomes (KEGG) and Ghost KOALA databases. A total of 10 xenobiotics metabolisms were detected and these were amino benzoate and steroid degradation, phenylalanine metabolism, synthesis and degradation of ketones, fatty acid degradation, caprolactam, ethylbenezene, chloroalkane and chloroalkene, geraniol, and limonene and pinene degradations. Mean values of TPH (mg/L) ranged from 1.58 to 23.48 in the samples. Furthermore, sample 1 with the least TPH had no xenobiotics metabolism while sample 2 with the highest TPH had the highest number of xenobiotic metabolisms. Dioxygenase, monoxygenase, dehydrogenase and acyltransferase enzymes were the most commonly annotated genes in our samples. Annotated bacteria classes in decreasing order were Alphaproteobacteria > Firmicutes > Gammaproteobacteria > Betaproteobacteria. Correlation analysis between levels of TPH and various annotated metabolisms gave a significant (p < 0.05) and strong positive R2 value (> 0.90). The findings in this study indicate that TPH coupled with metagenomic assessment of xenobiotics metabolic activities is a better way of monitoring biodegradation capacity of an impacted ecosystem.
Mosquito species of the Anopheles gambiae complex represent the major vectors of human malaria and they pose an enormous burden on global health and economies. Every year 300–500 million people are infected by malaria and over a million people die as consequence of Plasmodium parasite infections. Disease endemic countries often do not have the economic resources and the logistics to sustain control efforts like the massive and prolonged use of insecticides, the use of Long Lasting Insecticide Treated Nets (LLITN), Indoor Residual Sprays (IRS), Larviciding (abortion of metamorphosis) and adequate environmental sanitation. New control strategies that have sustainable effects are desperately needed. This article, therefore, considered the unprecedented effort aimed at generating new molecular tools and a comprehensive knowledge of biology and the genetics of Anopheline mosquitoes which has culminated in the sequencing of the A. gambiae genome and development of gene transfer technology for a series of vectors species. The article also looked into the molecular advances that have been made to express genes that can block the transmission of Plasmodium in model systems or express traits facilitating the implementation of sterile insect techniques for vector control.