Search

Antibiotics discovery was a significant breakthrough in the field of therapeutic medicines, but the over (mis)use of such antibiotics (in parallel) caused the increasing number of resistant bacterial species at an ever-higher rate. This study was thus devised to assess the multi-drug resistant bacteria present in sanitation-related facilities in human workplaces. In this regard, samples were collected from different gender, location, and source-based facilities, and subsequent antibiotic sensitivity testing was performed on isolated bacterial strains. Four classes of the most commonly used antibiotics i.e., β-lactam, Aminoglycosides, Macrolides, and Sulphonamides, were evaluated against the isolated bacteria. The antibiotic resistance profile of different (70) bacterial strains showed that the antibiotic resistance-based clusters also followed the grouping based on their isolation sources, mainly the gender. Twenty-three bacterial strains were further selected for their 16s rRNA gene based molecular identification and for phylogenetic analysis to evaluate the taxonomic evolution of antibiotic resistant bacteria (ARB). Moreover, the bacterial resistance to Sulphonamides and beta lactam was observed to be the most and to Aminoglycosides and macrolides as the least. Plasmid curing was also performed for multidrug resistant (MDR) bacterial strains, which significantly abolished the resistance potential of bacterial strains for different antibiotics. These curing results suggested that the antibiotic resistance determinants in these purified bacterial strains are present on respective plasmids. Altogether, the data suggested that the human workplaces are the hotspot for the prevalence of MDR bacteria and thus may serve as the source of horizontal gene transfer and further transmission to other environments. [ABSTRACT FROM AUTHOR]

This study examined properties of soil and runoff water under different land uses: forestry, pasture, cropping and fallow. The moisture level was found higher in the forest soil, while fallow and pasture soils showed a similar level of moisture. In top soil, the water holding capacity of pasture and forest soils was higher than other soils, especially that under cropping; the sub-soil held more water (12.1 %) than the top soil (10.3 %). The lower moisture level in cultivated or fallow lands could be attributed to the lower soil organic matter. Carbon concentration in the soils varied in the order forest > pasture > fallow > crop land. Across land uses, the concentrations of cations differed in the order: Ca > Mg > Na > K. Relatively higher concentrations of nutrients and lower pH were obtained in the top soil and sub-soil of the forest land. Forest and pasture catchments showed lower Na in soil. Regression analysis showed higher correlation between soil carbon and soil moisture, water holding capacity and nutrients. The nutrients concentrations were higher in forest soil and lowest in the soils of fallow and agricultural lands. The cations in the runoff water varied in the order Ca > Mg > Na > K, being highly consistent with that in the soil in each land use. Calcium concentrations in the runoff varied in the order forest > pasture > crop > fallow. Magnesium concentration was higher in forest runoff than other land uses, whereas higher K concentration was in pasture runoff. Higher total solids in the runoff of fallow land indicate soil erosion. The study highlights the value of plantation as a measure for land management. [ABSTRACT FROM AUTHOR]