| Autor: |
Aishwarya Pradeep Rao, Pratibha S., N. S. Srikanth, N. Shashidhara, T. Venkatesh |
| Jazyk: |
angličtina |
| Rok vydání: |
2014 |
| Předmět: |
|
| Zdroj: |
Journal of Krishna Institute of Medical Sciences University, Vol 03, Iss 02, Pp 43-54 (2014) |
| Druh dokumentu: |
article |
| ISSN: |
2231-4261 |
| Popis: |
Background: Lead poisoning is a prevalent health hazard in today's world of industrialization and is gaining the concern of medical professionals globally. The first organisms in the biosphere to be affected by this are the microorganisms. Many studies have established that metal tolerance is accompanied by antibiotic resistance as both the genes are present on plasmids. Aims and Objectives: The study was conducted to identify the concentrations of lead at which the microbial growth and antibiotic sensitivity was affected and also to identify whether any of the key metabolic activities were influenced. Microorganisms like Escherichia coli, Staphylococcus aureus and Candida albicans. Pseudomonas aeruginosa were chosen due to their increasing importance as a potent hospital acquired pathogen. Material and Methods: American Type Culture Collection (ATCC) strains were chosen and exposed to varying concentrations of lead acetate ranging from 1 to 1000 ppm. The growth was quantitatively analyzed spectrophotometrically at 600 nm. The antibiogram was done using disk diffusion method. The sugar fermenting property and the amino acid utilization was studied as they are the basic requirements for growth of any microorganism. Results: On exposure to lead, a decrease in the growth was seen with the three organisms but the growth pattern was different with Pseudomonas as it showed a sudden increase at 100 ppm accompanied by the production of H S at certain concentrations. The 2 antibiotic sensitivity tests which were carried out after exposure to lead, showed a resistance pattern to the β lactam group of antibiotics, hence implying that tolerance to the heavy metal affected the sensitivity of these organisms to the antibiotics. The biochemical tests showed no change in the presence of lead. Lead may exist in the soil in various concentrations but may exert a selective pressure only at certain concentrations. It has been established that a pattern exists between the antibiotic resistance and tolerance to lead, but since there seems to be no effect on the constitutional properties of the microorganisms, it can be concluded that heavy metal tolerance may have an effect only on plasmid conferred properties for the microorganisms. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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